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There are two recent articles that are, if not interesting, possibly important in the direction of cellular regulation, adaptation, and decline. One deals with apoptosis, or cell death, which is synchronized with recovery of membrane and protein breakdown for reuse in synthesis and maintenance. The other is a new perspective to Alzhemier’s Disease, for which there is no effective pharmacotherapy. In both cases, the stresses of the cell are critical to the responce to the environment. This is not just about the classical transcriptomics story. This is a perfect followup to the just posted research on the regulatory role of a small RNA that is related to, but distinct from silencing RNA, and also the revelations about lncRNA.
Protein Helps Cells Adapt—or Die
Scientists show how cell stress both prevents and promotes cell suicide in a study that’s equally divisive.
By Ruth Williams | July 3, 2014
A cellular stress pathway called the unfolded-protein-response (UPR) both activates and degrades death receptor 5 protein (DR5), which can promote or prevent cell suicide, according to a paper published in Science today (July 3). The theory is that initial stress blocks cell suicide, or apoptosis, to give the cell a chance to adapt, but that if the stress persists, it eventually triggers apoptosis.
“This work has made the most beautiful simplification of all this big complex mess. Basically, they identified and pinpointed the specific protein involved in the switching decision and explain how the decision is made,” said Alexei Korennykh, a professor of molecular biology at Princeton University, who was not involved in the work.
But Randal Kaufman of the Sanford-Burnham Medical Research Institute in La Jolla, California, was not impressed. He questioned the physiological relevance of the experiments supporting the authors’ main conclusions about this key cellular process.
Protein folding in a cell takes place largely in the endoplasmic reticulum (ER), but if the process goes awry, unfolded proteins accumulate, stressing the ER. This triggers the UPR, which shuts down translation, degrades unfolded proteins, and increases production of protein-folding machinery. If ER stress is not resolved, however, the UPR can also induce apoptosis.
Two main factors control the UPR—IRE1a and PERK. IRE1a promotes cell survival by activating the transcription factor XBP1, which drives expression of cell-survival genes. PERK, on the other hand, activates a transcription factor called CHOP, which in turn drives expression of the proapoptotic factor DR5.
Peter Walter of the University of California, San Francisco, and his colleagues have now confirmed that CHOP activates DR5, showing that it is a cell-autonomous process. But they have also found that IRE1a suppresses DR5, directly degrading its mRNA through a process called regulated IRE1a-dependent degradation (RIDD). Inhibition of IRE1a in a human cancer cell line undergoing ER stress both prevented DR5 mRNA decay and increased apoptosis.
However, in an e-mail to The Scientist, Kaufman expressed concern that “the significance of RIDD has not been demonstrated in a physiologically-relevant context.”
Walter insisted that the evidence for RIDD’s existence is “crystal clear.” His only concession was that “the effects aren’t 100 percent,” he said, because “RIDD degrades mRNA by a few-fold,” making it difficult to measure.
This RIDD debate aside, the researchers have also sparked a rumpus with their finding that IRE1a expression switches off just 24 hours after ER stress initiation, leaving PERK to drive the cell toward apoptosis. “We and others have evidence that suggests another model,” said Scott Oakes, a professor of pathology at the University of California, San Francisco, “which is that both PERK and IRE1a under high stress will send out death signals.”
Whether IRE1a promotes or inhibits apoptosis under extreme stress “is controversial,” said Ira Tabas, a professor at Columbia University in New York City. But it’s essential that scientists figure it out. Cell death from ER stress is a pathological process in many major diseases, Tabas said, and there are IRE1a inhibitors in pharmaceutical development. “It is very important because under high stress you have two different views here,” said Oakes. “One is that you want to keep IRE1a on, the other is that you want to shut it off.”
Because ER stress is central to many diseases, “a lot of people are passionate about it,” said Tabas, explaining the polemic views. “Who’s right? . . . I think it depends on the context in which the experiments are done—one pathway may be important in some settings, and another pathway may be important in different settings,” he suggested. What might help to resolve the issues, he said, will be “in vivo causation studies using actual disease models.”
Researchers will continue to debate. So, said Walter, “we’ll have to see what holds-up five years from now.”
M. Lu et al., “Opposing unfolded-protein-response signals converge on death receptor 5 to control apoptosis,” Science, 345:98-101, 2014.
It is one of the big scientific mysteries of Alzheimer’s disease: Why do some people whose brains accumulate the plaques and tangles so strongly associated with Alzheimer’s not develop the disease?
Now, a series of studies by Harvard scientists suggests a possible answer, one that could lead to new treatments if confirmed by other research.
The memory and thinking problems of Alzheimer’s disease and other dementias, which affect an estimated seven million Americans, may be related to a failure in the brain’s stress response system, the new research suggests. If this system is working well, it can protect the brain from abnormal Alzheimer’s proteins; if it gets derailed, critical areas of the brain start degenerating.
“This is an extremely important study,” said Li-Huei Tsai, director of the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology, who was not involved in the research but wrote a commentary accompanying the study. “This is the first study that is really starting to provide a plausible pathway to explain why some people are more vulnerable to Alzheimer’s than other people.”
An image of tau tangles in the brain, often a hallmark of Alzheimer’s disease.
The research, published on Wednesday in the journal Nature, focuses on a protein previously thought to act mostly in the brains of developing fetuses. The scientists found that the protein also appears to protect neurons in healthy older people from aging-related stresses. But in people with Alzheimer’s and other dementias, the protein is sharply depleted in key brain regions.
Experts said if other scientists could replicate and expand upon the findings, the role of the protein, called REST, could spur development of new drugs for dementia, which has so far been virtually impossible to treat. But they cautioned that much more needed to be determined, including whether the decline of REST was a cause, or an effect, of brain deterioration, and whether it was specific enough to neurological diseases that it could lead to effective therapies.
“You’re going to see a lot of papers now following up on it,” said Dr. Eric M. Reiman, executive director of the Banner Alzheimer’s Institute in Phoenix, who was not involved in the study. “While it’s a preliminary finding, it raises an avenue that hasn’t been considered before. And if this provides a handle on which to understand normal brain aging, that will be great, too.”
REST, a regulator that switches off certain genes, is primarily known to keep fetal neurons in an immature state until they develop to perform brain functions, said Dr. Bruce A. Yankner, a professor of genetics at Harvard Medical School and the lead author of the new study. By the time babies are born, REST becomes inactive, he said, except in some areas outside the brain like the colon, where it seems to suppress cancer.
“Why should a fetal gene be coming on in an aging brain?” he wondered. He hypothesized that it was because in aging, as in birth, brains encounter great stress, threatening neurons that cannot regenerate if harmed.
His team discovered that REST appears to switch off genes that promote cell death, protecting neurons from normal aging processes like energy decrease, inflammation and oxidative stress.
Analyzing brains from brain banks and dementia studies, the researchers found that brains of young adults ages 20 to 35 contained little REST, while healthy adults between the ages of 73 and 106 had plenty. REST levels grew the older people got, so long as they did not develop dementia, suggesting that REST is related to longevity.
But in people with Alzheimer’s, mild cognitive impairment, frontotemporal dementia and Lewy body dementia, the brain areas affected by these diseases contained much less REST than healthy brains.
This was true only in people who actually had memory and thinking problems. People who remained cognitively healthy, but whose brains had the same accumulation of amyloid plaques and tau tangles as people with Alzheimer’s, had three times more REST than those suffering Alzheimer’s symptoms. About a third of people who have such plaques will not develop Alzheimer’s symptoms, studies show.
REST levels dropped as symptoms worsened, so people with mild cognitive impairment had more REST than Alzheimer’s patients. And only key brain regions were affected. In Alzheimer’s, REST steeply declined in the prefrontal cortex and hippocampus, areas critical to learning, memory and planning. Other areas of the brain not involved in Alzheimer’s showed no REST drop-off.
It is not yet possible to analyze REST levels in the brains of living people, and several Alzheimer’s experts said that fact limited what the new research could prove.
John Hardy, an Alzheimer’s researcher at University College London, cautioned in an email that information from post-mortem brains could not prove that a decline in REST caused dementia because death might produce unrelated damage to brain cells.
To investigate further, the team conducted what both Dr. Tsai and Dr. Reiman called a “tour de force” of research, examining REST in mice, roundworms and cells in the lab.
“We wanted to make sure the story was right,” Dr. Yankner said. “It was difficult to believe at first, to be honest with you.”
Especially persuasive was that mice genetically engineered to lack REST lost neurons as they aged in brain areas afflicted in Alzheimer’s.
Dr. Yankner said REST appeared to work by traveling to a neuron’s nucleus when the brain was stressed. In dementia, though, REST somehow gets diverted, traveling with toxic dementia-related proteins to another part of the neuron where it is eventually destroyed.
Experts said the research, while intriguing, left many unanswered questions. Bradley Wise of the National Institute on Aging’s neuroscience division, which helped finance the studies, said REST’s role needed further clarification. “I don’t think you can really say if it’s a cause of Alzheimer’s or a consequence of Alzheimer’s” yet, he said.
Dr. Samuel E. Gandy, an Alzheimer’s researcher at Mount Sinai Medical Center, wondered if REST figured only in neurodegenerative diseases or in other diseases, too, which could make it difficult to use REST to develop specific treatments or diagnostic tests for dementia.
“My ambivalence is, is this really a way that advances our understanding of the disease or does this just tell us this is even more complicated than we thought?” he said.
Dr. Yankner’s team is looking at REST in other neurological diseases, like Parkinson’s. He also has thoughts about a potential treatment, lithium, which he said appears to stimulate REST function, and is considered relatively safe.
But he and other experts said it was too early. “I would hesitate to start rushing into lithium treatment” unless rigorous studies showed that it could forestall dementia, said Dr. John C. Morris, an Alzheimer’s researcher at Washington University in St. Louis.
Still, Dr. Morris said, the REST research the team conducted so far is “very well done, and certainly helps support this idea that we’ve all tried to understand about why Alzheimer’s is age-associated and why, while amyloid is necessary for the development of Alzheimer’s disease, it certainly is not sufficient.”
He added, “There have to be some other processes and triggers that result in Alzheimer’s.”
Correction: March 19, 2014
Because of an editing error, an earlier version of this article misstated the gender of Dr. Li-Huei Tsai. Dr. Tsai is a woman.
Physicians’ View of Supreme Court on an Issue of Public Health
The physicians are under considerable stress. They have a minimum of 8 years of post graduate university education to practice as a generalist or in a medical, pediatric, gynecological or surgical related specialty. A significant loss is incurred in the cost of loans for education to many. A significant sacrifice is made in time for family. A primary obligation is incurred toward the wellbeing of the patient, and the community that has to be respected and protected by civil law.
Supreme Court Issues Hobby Lobby Decision
By Joyce Frieden, News Editor, MedPage Today Published: Jun 30, 2014
The Supreme Court has struck down the Affordable Care Act requirement that employers must include no-cost contraceptive coverage in employee health insurance plans. The 5-4 decision decision issued today in the Hobby Lobby case (Burwell v. Hobby Lobby Stores, Inc.) follows conflicting appellate court rulings in cases involving businesses that objected to the ACA’s birth control requirement on religious grounds. The businesses said the ACA stepped on their religious freedoms.
The 2010 health law mandates that all health plans provide preventive services — including birth control — free of cost-sharing. But some corporations — most notably arts-and-crafts giant Hobby Lobby and its sister company Mardel, a Christian bookstore chain — sued the Department of Health and Human Services to be exempted from having to comply with the mandate. In its 5-4 decision, written by Justice Samuel Alito, the Court ruled that the mandate violates the Religious Freedom Restoration Act of 1993, “which prohibits the ‘Government [from] substantially burden[ing] a person’s exercise of religion’” unless it shows that doing so is “in furtherance of a compelling governmental interest” and “is the least restrictive means” of doing do. The decision summary also notes that the Department of Health and Human Serivces (HHS) “argues that the companies cannot sue because they are for-profit corporations, and that the owners cannot sue because the regulations apply only to the companies, but that would leave merchants with a difficult choice:
give up the right to seek judicial protection of their religious liberty or forgo the benefits of operating as corporations.
RFRA’s text shows that Congress designed the statute to provide very broad protection for religious liberty and did not intend to put merchants to such a choice.” Donna Harrison, MD, executive director of the American Association of Pro-Life Obstetricians & Gynecologists (AAPLOG), noted that Hobby Lobby was in particular objecting to very specific contraceptives — the emergency contraceptive Ella and intrauterine devices, which she noted are capable of killing embryos, either by preventing their implantation or killing them after they have been implanted.
Art Caplan, PhD, director of the medical ethics division at the NYU Langone Medical Center in New York City, oberved “decision could have a very negative impact” on women’s ability to obtain contraception, and “it could affect many women even if only a small percentage of companies followed suit.” “The other problem,” he told MedPage Today in a video interview, “is that if your employer says ‘I’m not covering contraception,’ you may decide to go with methods that don’t involve pharmaceutical control, or you may rely on something like emergency contraception” — decisions that could lead to more abortions, which would be
an ironic outcome since many employers’ objections to contraception revolve around their objections to abortion.
Harrison, of AAPLOG, noted that the decision should be reassuring to physicians who object to prescribing particular forms of contraception that they see as abortifacients, since insurers may have been considering excluding such doctors from their provider networks if the mandate had been upheld. “This will help incentivize insurers to not exclude ‘conscientious doctors’ from their networks,” she said.
More Physician Groups Weigh In
Many of the other physician groups issuing statements today expressed disappointment in the ruling.
“Allowing for-profit employers to exclude coverage for contraception is itself deeply concerning because of the demonstrated adverse impact it will have on women’s health,” David Fleming, MD, president of the American College of Physicians, said in a statement. “And, “the ruling clearly does not preclude for-profit employers from challenging such mandates (vaccinations), or the courts from granting further coverage exemptions.”
Rebecca Sokol, MD, president of the American Society for Reproductive Medicine in Washington, said in a statement that her organization “profoundly disagrees” with the decision. “Allowing an employer to impose their beliefs about reproduction on their staff is simply wrong, particularly when those beliefs are
so clearly misinformed on the scientific and medical facts,” Sokol said.
“In no other field of medicine do we allow employers to substitute their judgment for that of patients and physicians; it should not be allowed just because the subject matter is reproduction.”
Between Women and Their Physicians
Lin-Fan Wang, MD, reproductive health advocacy fellow at Physicians for Reproductive Health in New York City, said in a video interview that
“decisions about contraception should really be made between a woman and her doctor, and not by her employer.”
Wang recounted the story of one of her own patients, a woman who had recently had a baby and then went back to work, and was having trouble remembering to take her birth control pills. “She chose one of the intrauterine devices … because it was one of the most effective forms of contraception and she didn’t have to think about it every day,” she said. “Luckily her insurance plan covered the cost of this very expensive form of contraception, but
under the ruling today, patients like [her] might not be able to choose that method
and she may end up having to choose a method that is hard for her to take or she’s not happy with.” Reproductive rights groups also expressed their concerns. Bebe Anderson, JD, director of the U.S. Legal Program at the Center for Reproductive Rights in New York City, called the decision “an affront to women of this country.”
“As Justice [Ruth Bader] Ginsburg recognized in her dissent, this decision makes it very difficult for women to get some of the best long-acting reversible forms of contraception,” Anderson told MedPage Today in a video interview. “For example, IUDs are as expensive as 1 month’s pay for someone working at minimum wage.”
Cecile Richards, president of the Planned Parenthood Action Fund, called the ruling “stunning.” On a call with reporters she said it was no coincidence that the majority opinion was decided by five male justices. “It is endlessly frustrating for women that decisions about their healthcare are being made by people who never need to use birth control, and it is no coincidence that all three women on the court signed today’s dissent,” Richards said. On the same call, Marcia Greenberger, co-president of the National Women’s Law Center, said the decision was “a bitter pill for women to swallow …These [plaintiffs] and other closely held companies
will now have license to harm their female employees in the name of the company’s religion, and
ignore the moral and practical considerations of women themselves.”
Other Implications
Several commenters noted that, although the majority opinion specifically states that this ruling does not apply to religious objections to other healthcare benefits such as vaccinations and blood transfusions, this opens up the way for plaintiffs to sue about those as well. “Regardless of what they said, they’ve opened Pandora’s box and set a precedent,” said Ilyse Hogue, president of NARAL Pro-Choice America. The Tenth Circuit Court of Appeals in Denver ruled in June 2013 that
Hobby Lobby should be given the opportunity to show its religious beliefs would be violated by either complying with the law or being forced to pay large fines.
Hobby Lobby faced penalties amounting to $1.3 million a day starting in the summer of 2013 if it didn’t provide FDA-approved contraceptive methods in its self-insured health plans, which cover 13,000 employees. But a court issued an injunction in July that prevented the penalty from taking effect.
When Religious Freedom Clashes with Access to Care
Glenn Cohen, J.D., Holly Fernandez Lynch, J.D., M.Bioethics, and Gregory D. Curfman, M.D.
July 2, 2014 DOI: 10.1056/NEJMp1407965
At the tail end of this year’s Supreme Court term, religious freedom came into sharp conflict with the government’s interest in providing affordable access to health care. In a consolidated opinion inBurwell v. Hobby Lobby Stores and Conestoga Wood Specialties Corp. v. Burwell (collectively known as Hobby Lobby) delivered on June 30, the Court sided with religious freedom, highlighting the limitations of our employment-based health insurance system.
Hobby Lobby centered on the contraceptives-coverage mandate, which derived from the Affordable Care Act (ACA) mandate that many employers offer insurance coverage of certain “essential” health benefits, including coverage of “preventive” services without patient copayments or deductibles. The ACA authorized the Department of Health and Human Services (HHS) to define the scope of those preventive services, a task it delegated to the Institute of Medicine, whose list included all 20 contraceptive agents approved by the Food and Drug Administration. HHS articulated various justifications for the resulting mandate, including the fact that many Americans have difficulty affording contraceptives despite their widespread use and
the goal of avoiding a disproportionate financial burden on women.
Under the regulation, churches are exempt from covering contraception for their employees, and nonprofit religious organizations may apply for an “accommodation,” which shifts to their insurance companies (or other third parties) the responsibility for providing free access. However,
HHS made no exception for for-profit, secular businesses with religious owners.
Hobby Lobby, a craft-store chain with more than 13,000 employees, is a closely held, for-profit corporation owned by a Protestant family that operates the business in accordance with its Christian principles — for example, donating a portion of proceeds to Christian missions and remaining closed on Sundays. The family does not object to providing coverage for some contraceptives, but
it challenged the mandate because it includes contraceptive methods that the family believes cause abortion by preventing implantation of a fertilized egg.
The challenge in Hobby Lobby was not about the Constitution or its First Amendment. Rather, it hinged on the Religious Freedom Restoration Act of 1993 (RFRA), which was Congress’s response to a Supreme Court decision holding that
even if a law in fact burdened religion, it could stand as long as it was not intended to burden religion (was “neutral”),
applied without regard to religious beliefs or practices (was “generally applicable”), and
was rationally related to a legitimate government interest — a low bar.
RFRA applies when a federal law is deemed to “substantially” burden a person’s exercise of religion, even if it is neutral and generally applicable. Such laws may be enforced against religious objectors only when they further a compelling government interest using the least restrictive means available. This is the most demanding standard of judicial review, and few laws meet its requirements. In a 5-to-4 decision the Court found that the contraceptives-coverage mandate did not.
In its RFRA analysis, the Court had to address several key questions:
Are closely held, for-profit corporations “persons” for the purposes of RFRA protection?
Can corporations exercise religion?
Does the contraceptives-coverage mandate substantially burden religion?
Does the mandate advance a compelling government interest? And
are there less restrictive alternatives that would achieve the same result?
In a ruling in which Justice Samuel Alito wrote for the majority (joined by Chief Justice John Roberts and Justices Antonin Scalia, Anthony Kennedy, and Clarence Thomas), the mandate came up short. The majority concluded that RFRA was intended to protect even for-profit corporations and that
corporations may exercise religion,
rejecting as unreasonable any definition of “person” that would include some but not all corporations.
The majority also concluded that the mandate did place a substantial burden on the companies’ religious beliefs, given the dramatic financial consequences of noncompliance (for example, Hobby Lobby would have faced a fine of $475 million per year) and
the fact that the government had extended other exemptions and accommodations in recognition of that burden.
The majority assumed that the government has a compelling interest in promoting free access to contraceptive agents, but it held that
the government had failed to advance that interest in the least restrictive way, given
the possibility of extending its existing exemptions and accommodations to for-profit corporations
Thus, the Court held that as applied to closely held, for-profit corporations with religious objections, the mandate violates RFRA. It was careful, however, to restrict the decision to the case before it, refraining from opining on the implications for other types of employers or objections to other health care services, which it cautioned must be addressed on a case-by-case basis. Nonetheless, the case may have broad practical impact, since
approximately 90% of all U.S. companies are closely held, and
“closely held” is not synonymous with “small.”
Justice Ruth Bader Ginsburg issued a sharp dissent, in which she was joined by Justice Sonia Sotomayor and in large part by Justices Elena Kagan and Stephen Breyer. Delivering her opinion from the bench, Justice Ginsburg underscored the burden that the majority decision would allow to be placed on women in favor of religious objectors:
“Today’s potentially sweeping decision . . . discounts the disadvantages religion-based opt outs impose on others, in particular, employees who do not share their employer’s religious beliefs.”
Hobby Lobby‘s outcome is of concern to U.S. health care professionals because
our health insurance system is still largely dependent on employers.
Employers and employees may have fundamentally different perspectives on which medical interventions are acceptable,
particularly when the employer’s fundamental mission is not to advance specific religious beliefs and
its employees are therefore unlikely to be drawn exclusively from its own religious group.
The Court’s decision allows the beliefs of employers of various sizes and corporate forms to trump the beliefs and needs of their employees, potentially influencing the types of care that will be affordable and accessible to individuals and permitting employers to intrude on clinician–patient relationships.
The case also has important implications for efforts to achieve compromise between religious freedom and health care access. The Obama administration’s attempts to compromise on the contraceptives-coverage mandate ultimately backfired, since its efforts were used to demonstrate that
applying the mandate even to secular employers was not necessarily the only way to achieve the government’s interests.
In the future, regulators may be less willing to seek compromise lest their efforts be similarly used against them — and it is bad news for all of us if health policy can be made only through polarization and rancor rather than compromise. On the other hand, in other contraceptives-mandate cases working their way through the courts, nonprofit religious employers argue that the government’s accommodations do not go far enough in protecting their religious freedom, essentially requiring them to deputize a third party to commit what they think is a sin on their behalf.
Finally, in the wake of Hobby Lobby, we may anticipate challenges to other medical services that some religions find objectionable, such as vaccinations, infertility treatments, blood transfusions, certain psychiatric treatments, and even hospice care. Hobby Lobby‘s implications may also extend into civil rights law, with employers asking to “opt out” of laws intended to protect people from employment and housing discrimination based on religion, race, sex, national origin, or pregnancy status. Although the majority deemed these slippery-slope concerns unrealistic, the dissent expressed serious concerns.
Though the decision applies only to closely held, for-profit corporations, it sets a precedent for religious exemptions that could have sweeping implications — and reflects the Supreme Court’s great potential impact on U.S. health care. Yet the Court was applying Congress’s statute, and
Congress could, if it chose, scale back the protection offered to religious objectors — a good reason to share public reactions to the decision with our elected representatives.
BUFFER ZONES, BUBBLE ZONES, AND ABORTION CLINICS — ANOTHER WOMEN’S HEALTH CASE
In 2000, concerned about clashes between antiabortion protesters and women seeking abortions, the Massachusetts legislature established an 18-ft radius around the entrances and driveways of facilities providing abortions and specified that within that area, no person could, without consent, approach within 6 ft of another person (a so-called “bubble zone”) for the purpose of protesting, leafleting, counseling, or education. In 2007, the legislature concluded that law was not effective enough and increased its stringency, imposing a 35-ft fixed buffer zone with few exceptions. The law was challenged on free-speech grounds in a case called McCullen v. Coakley, and on June 26, 2014, the U.S. Supreme Court unanimously struck it down as unconstitutional.
The lead opinion by Chief Justice John Roberts, joined by four other justices, noted that sidewalks and public ways hold a “special position in terms of First Amendment protection because of their historic role as sites for discussion and debate.” Although it was abortion that had motivated the statute, the Court held that the law was content- and viewpoint-neutral: it did not focus on what was said but on where it was said, and it burdened all speech, not merely disfavored speech.
On this point, the four remaining justices disagreed. Nevertheless, the Court held that the statute failed the second part of the relevant constitutional test because it was not “narrowly tailored to serve a significant governmental interest.” In particular, though the Court recognized that the buffer zones furthered the state’s interests in “ensuring public safety” on streets and sidewalks and in “preserving access to adjacent healthcare facilities,” it determined that
the law problematically criminalized not only protests,
but also sidewalk counseling, which could not be done at a distance of 35 ft.
It also found that the buffer zones burdened “substantially more speech than necessary to achieve” the state’s interest
and suggested a plethora of less intrusive means the state could have used instead, some of which are used in other states.
Although the decision deals another blow to abortion rights, that blow is not as substantial as some had feared: the finding that the law was content- and viewpoint-neutral allows for the possibility that Massachusetts and other states could pass similar but narrower laws. Moreover, the Court left open the future of the floating “bubble zone” around women approaching clinics for abortions — the strategy that Massachusetts had used from 2000 to 2007 and one that the Court upheld in a Colorado case in 2000. Several justices, however, indicated a willingness to revisit that decision in future litigation.
See §§2000bb–1(a), (b) (requiring the Government to “demonstrat[e] that application of [a substantial] burden to the person . . . is the least restrictive means of furthering [a] compelling governmental interest” (emphasis added)).
This article is concerned only with updating the importance of key nutrients for maintenance of health. Nutritional losses are associated with memory loss, impaired immunity, and loss of lean body mass.
Low levels of omega-3 fatty acids may cause memory problems
ST. PAUL, Minn. – A diet lacking in omega-3 fatty acids, nutrients commonly found in fish, may cause your brain to age faster and lose some of its memory and thinking abilities, according to a study published in the February 28, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology. Omega-3 fatty acids include the nutrients called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
salmon dinner
“People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging,” said study author Zaldy S. Tan, MD, MPH, of the Easton Center for Alzheimer’s Disease Research and the Division of Geriatrics, University of California at Los Angeles.
For the study, 1,575 people with an average age of 67 and free of dementia underwent MRI brain scans. They were also given tests that measured mental function, body mass and the omega-3 fatty acid levels in their red blood cells.
The researchers found that people whose DHA levels were among the bottom 25 percent of the participants had lower brain volume compared to people who had higher DHA levels. Similarly, participants with levels of all omega-3 fatty acids in the bottom 25 percent also scored lower on tests of visual memory and executive function, such as problem solving and multi-tasking and abstract thinking.
ABSTRACT In patients with chronic kidney disease (CKD), loss of cellular proteins increases the risks of morbidity and mortality. Persistence of muscle protein catabolism in CKD results in striking losses of muscle proteins as whole-body protein turnover is great; even small but persistent imbalances between protein synthesis and degradation cause substantial protein loss. No reliable methods to prevent CKD-induced muscle wasting currently exist, but mechanisms that control cellular protein turnover have been identified, suggesting that therapeutic strategies will be developed to suppress or block protein loss. Catabolic pathways that cause protein wasting include activation of the ubiquitin-proteasome system (UPS), caspase-3, lysosomes and myostatin (a negative regulator of skeletal muscle growth). These pathways can be initiated by complications associated with CKD, such as metabolic acidosis, defective insulin signalling, inflammation, increased angiotensin II levels, abnormal appetite regulation and impaired microRNA responses. Inflammation stimulates cellular signalling pathways that activate myostatin, which accelerates UPS-mediated catabolism. Blocking this pathway can prevent loss of muscle proteins. Myostatin inhibition could yield new therapeutic directions for blocking muscle protein wasting in CKD or disorders associated with its complications.
We’re Fishing the Oceans Dry. It’s Time to Reconsider Fish Farms.
Food and Agriculture Organization of the United Nations -State of World Fisheries and Aquaculture 2014
Aquaculture has gotten much greener, with American innovators leading the way.
When I meet Kenny Belov mid-morning at San Francisco’s Fisherman’s Wharf, the boats that would normally be out at sea chasing salmon sit tethered to their docks. The steady breeze coursing through the bay belies choppier conditions farther out—so rough that the local fishermen threw in the towel for the fifth morning in a row. Belov scans the horizon as he explains this, feet away from the warehouse of his sustainable seafood company, TwoXSea. Because his business hinges on what local fishermen can bring in, he’s used to coping with wild fish shortages.
If we continue to fish at the current pace, some scientists predict we’ll be facing oceans devoid of edible marine creatures by 2050.
But unlike these fishermen, Belov has a stash of treasure in his warehouse, as he soon shows me: a golf-cart-size container of plump trout, their glossy bodies still taut from rigor mortis. The night before, Belov drove north to Humboldt to help “chill kill” the fish by submerging them live into barrels of slushy ice water. Belov can count on shipments of these McFarland Springs trout every week—because he helped grow them himself on a farm.
For many consumers, aquaculture lost its appeal after unappetizing news spread about commercial fish farms—like fish feed’s pressure on wild resources, overflowing waste, toxic buildup in the water, and displacement of natural species. But consider this: Our appetite for seafood continues to rise. Globally, we’ve hungered for 3.2 percent more seafood every year for the last five decades, double the rate of our population. Yet more than four-fifths of the world’s wild fisheries are overexploited or fully exploited (yielding the most fish possible with no expected room for growth). Only 3 percent of stocks are considered underexploited—meaning they have any significant room for expansion. If we continue to fish at the current pace, some scientists predict we’ll be facing oceans devoid of edible marine creatures by 2050.
Aquaculture could come to the rescue. The Food and Agriculture Organization of the United Nations predicts that farmed fish will soon surpass wild-caught; by 2030, aquaculture may produce more than 60 percent of fish we consume as food.
Food and Agriculture Organization of the United Nations “State of World Fisheries and Aquaculture” 2014 report
One of the most pressing concerns about aquaculture, though, is that many farmed fish are raised on a diet of 15 million tons a year of smaller bait fish—species like anchovies and menhaden. These bait—also known as forage fish—are ground up and converted into a substance called fishmeal. It takes roughly five pounds of them to produce one pound of farmed salmon. Bait fish are also used for nonfood products like pet food, makeup, farm animal feed, and fish oil supplements.
Forage fish are a “finite resource that’s been fully utilized.”
It may appear as though the ocean enjoys endless schools of these tiny fish, but they too have been mismanaged, and their populations are prone to collapse. They’re a “finite resource that’s been fully utilized,” says Mike Rust of NOAA’s fisheries arm. Which is disturbing, considering that researchers like those at Oceana argue that forage fish may play an outsize role in maintaining the ocean’s ecological balance, including by contributing to the abundance of bigger predatory fish.
And that’s where Belov’s trout come in: Though he swears no one can taste the difference, his fish are vegetarians. That means those five pounds of forage fish can rest easy at sea. It also means that the trout don’t consume some of the other rendered animal proteins in normal fishmeal pellets: bone meal, feather meal, blood meal, and chicken byproducts.
Belov and McFarland Springs’ owner David McFarland were inspired to switch to vegetarian feed in part by Rick Barrows, a USDA researcher. About six years ago, recounts Barrows, several USDA studies confirmed that fish rely on nutrients—vitamins, minerals, fatty acids, and protein—rather than fishmeal or fish oil, to thrive. If those nutrients could be found in other products, including purely plant-based substances, then aquaculture might not be so dependent on feeding fish other smaller fish.
Barrows and team began to test about 50 potential materials a year, and now have a database of 140 that anyone can browse through online. Belov was one of their first commercial partners. The plant-based food fed to McFarland Springs’ trout consists of a hearty blend of marine algae, freshwater micro algae, vitamins, minerals, flax, flax oil, corn, and nut waste. The resulting complete protein means the trout’s omega 3s are high and their omega 6s are low—a ratio that’s said to enhance anti-inflammatory properties. And “they don’t have the concentration of heavy metals that come from the bait fish,” Belov says. I took one of his rosy fillets home and turned it into trout lox; find the recipe here.
McFarland Springs manages the trout’s waste by funneling it out into a natural sagebrush pasture where it composts the soil.
Belov’s fish feed includes California nuts that are too broken or disfigured to be sold.
Barrows thinks region-specific material for this type of feed offers the most potential. For instance, his team learned that around 5 percent of California nuts can’t be sold because they’re broken or disfigured. They realized they could repurpose excess nut parts for the trout feed; the nut bits helped round out the complete protein. Lately, Barrows has become especially excited about turning barley surplus from the beer industry—which comes at a cheap price in Montana, where he’s based—into a feed-grade concentrate for trout feed.
“You can get just as much growth rate out of fishmeal-free feeds as fishmeal,” says Barrows. And his lab has proven as much with eight different fish species: cobia, Florida pompano, coho salmon, Atlantic salmon, walleye, yellowtail, and White seabass.
But the price difference still stands in the way for many fish farmers. Belov pays slightly more than $1/pound for his plant-based feed, whereas fishmeal pellets average around $0.71/pound. He sells his trout for $6.95/pound, about a dollar more than conventional. But he’s well positioned in the affluent Bay Area, and he usually sells out of his McFarland Springs trout well before the end of each week. As innovation continues in the realm of plant-based feeds, he’s hopeful, along with Barrows, that the price of the pellets will continue to drop.
Here in the United States, we consume plenty of farmed fish already, but only 5 percent of it is sourced domestically. “If we didn’t import so much farmed seafood,” implored Four Fish author Paul Greenberg in a recent New York Times op-ed, “we might develop a viable, sustainable aquaculture sector of our own.” It doesn’t just boil down to economics: The locations we generally export from, like China and South Asia, don’t have near the stringent environmental and health regulations as the US. “Growing more seafood at home would help with trade deficit, but also we could control the safety more,” says Barrows.
Though our current aquaculture sector is relatively tiny, US farmers are in a better position to innovate, because we have a sophisticated animal nutrition research center and feed sector, says NOAA’s Rust. “We’re the leading technical country in the world on feed.”
Belov wasn’t always open to aquaculture, and he still feels that fish—such as some salmon—with healthy wild fisheries attached to them should never be farmed. That way, environmentally responsible fishermen can stay in business. His long-term strategy for sustainable seafood? Draw from the “amazing [wild] fisheries that exist, and then you backfill with intelligent aquaculture, and yes, you can feed the planet with sustainable marine products.” Which may take more work, but as he puts it, “We depleted the ocean. It wasn’t anybody else’s fault. So it’s our job to fix it.”
Cell-free Protein Synthesis from a Release Factor 1 Deficient Escherichia coli Activates Efficient and Multiple Site-specific Nonstandard Amino Acid Incorporation
†Department of Chemical and Biological Engineering,‡Chemistry of Life Processes Institute, §Department of Chemistry, and Department of Molecular Biosciences,Northwestern University, Evanston, Illinois 60208,United States of America
Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, United States of America
# Systems Biology Institute, Yale University, West Haven, Connecticut 06516, United States of America
Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois 60611, United States of America
Institute of Bionanotechnology in Medicine, Northwestern University, Chicago, Illinois 60611, United States of America
Site-specific incorporation of nonstandard amino acids (NSAAs) into proteins
Site-specific incorporation of nonstandard amino acids (NSAAs) into proteins enables the creation of biopolymers, proteins, and enzymes with new chemical properties, new structures, and new functions. To achieve this, amber (TAG codon) suppression has been widely applied. However, the suppression efficiency is limited due to the competition with translation termination by release factor 1 (RF1), which leads to truncated products. Recently, we constructed a genomically recoded Escherichia coli strain lacking RF1 where 13 occurrences of the amber stop codon have been reassigned to the synonymous TAA codon (rEc.E13.ΔprfA). Here, we assessed and characterized cell-free protein synthesis (CFPS) in crude S30 cell lysates derived from this strain. We observed the synthesis of 190 ± 20 μg/mL of modified soluble superfolder green fluorescent protein (sfGFP) containing a single p-propargyloxy-l-phenylalanine (pPaF) or p-acetyl-l-phenylalanine. As compared to the parentrEc.E13 strain with RF1, this results in a modified sfGFP synthesis improvement of more than 250%. Beyond introducing a single NSAA, we further demonstrated benefits of CFPS from the RF1-deficient strains for incorporating pPaF at two- and five-sites per sfGFP protein. Finally, we compared our crude S30 extract system to the PURE translation system lacking RF1. We observed that our S30 extract based approach is more cost-effective and high yielding than the PURE translation system lacking RF1, 1000 times on a milligram protein produced/$ basis. Looking forward, using RF1-deficient strains for extract-based CFPS will aid in the synthesis of proteins and biopolymers with site-specifically incorporated NSAAs.
2014 Tang Prize in Biopharmaceutical Sciences awards to James P. Allison and Tasuku Honjo For the discoveries of CTLA-4 and PD-1 as immune inhibitory molecules that led to their applications in cancer immunotherapy 2014/06/19.
Founded by Dr. Samuel Yin in December 2012, the Tang Prize recognizes scholars conducting revolutionary research in the four major fields of Sustainable Development, Biopharmaceutical Science, Sinology, and the Rule of Law. The Prize is awarded with each category a cash reward of over US$1 million (NT$50 million). The Tang Prize Foundation hopes that recipients of the Prize will continue to innovate while cultivating and nurturing new talent in their respective fields.
Academia Sinica was commissioned by the Tang-Prize Foundation to administer the selection of Tang-Prize Laureates for the category of Biopharmaceutical Science, recognizing original biopharmaceutical or biomedical research that has led to significant advances towards preventing, diagnosing and/or treating major human diseases to improve human health.
James P. Allison and Tasuku Honjo were chosen among nearly a hundred nominees for their discoveries of CTLA-4 and PD-1 as immune inhibitory molecules, revealing ways to harness our incredibly powerful immune system to fight cancer and marking the beginning of the immunotherapy revolution.
A critical process in the immune response involves presentation of antigens to T cells by antigen-presenting cells, two key cell types in our immune system. This process is highly regulated by molecules that stimulate the response to ensure our mounting a sufficient immune response, especially in the event of invasion by pathogens, but also by molecules that inhibit the process to ensure the response is not excessive. Indeed, there is now a family of proteins on T cells involved in this regulatory process, which is designated the “CD28 receptor family” co-receptors, as CD28 is the first protein identified to have such function. They are divided into co-receptors transmitting stimulatory signals and co-receptors transmitting inhibitory signals. Each of these has its counterpart (ligand) on antigen-presenting cells belonging to the “B7 family”. Two most prominent inhibitory receptors on T cells are called CTLA-4 (cytotoxic T lymphocyte antigen-4, as it is first identified on cytotoxic T lymphocytes) and PD-1 (program death-1, as it is first identified to be associated with a type of cell death process called programmed cell death). Their ligands are designated as B7-1/B7-2 and PD-L1/PD-L2, respectively. These are also referred to as immune checkpoint receptors and ligands.
Our immune system is not perfect and at times, the regulatory mechanisms might be faulty, which in fact may be the basis of a variety of diseases. For example, autoimmune diseases may be related to the suppressive mechanism becoming weak and the individuals can mount excessive immune responses even to their own cells and tissues. Also, our immune system is capable of recognizing cancer cells and attacking them, in a process called immune surveillance. However, cancer cells are also equipped with machineries to evade the host anti-tumor activity, which is described as immune escape. For example, cancer cells can also express B7 family ligands on their surfaces and, by engaging the co-receptors transmitting inhibitory signals on T cells, they can inhibit the host anti-tumor T cell activity. By recognizing how cancer cells escape the immune surveillance, scientists have developed novel approaches to interfere with the ability of cancer cells to suppress the immune response, thus enhancing the ability of the host immune system to inhibit cancer cell growth.
Dr. James Allison, Chairman, Department of Immunology and Executive Director, Immunotherapy Platform at the University of Texas, MD Anderson Cancer Center, is one of two scientist to identify CTLA-4 as an inhibitory receptor on T-cells in 1995 and was the first to recognize it as a potential target for cancer therapy. His team then developed an antibody that blocks CTLA-4 activity and showed in 1996 that this antibody is able to help reject several different types of tumors in mouse models. This subsequently led to development of a monoclonal antibody drug, which has undergone clinical trials against stage 4 melanoma and been approved for treatment of melanoma by the U.S. FDA in 2011.
Dr. Tasuku Honjo, Professor, Department of Immunology and Genomic Medicine, Kyoto University, discovered PD-1 in 1992. His group subsequently established that PD-1 is an inhibitor regulator of the T cell response. Additional studies from his and other laboratories established that this protein plays a critical role in the regulation of tumor immunity and stimulated many groups to generate its blocker for the treatment of cancer. Antibodies against PD-1 have been approved by the U.S. FDA as an investigational new drug and developed for the treatment of cancer. One such antibody produced complete or partial responses in non-small-cell lung cancer, melanoma, and renal-cell cancer in clinical trials, and is predicted to be launched in 2015 for treatment of non-small cell lung cancer; this has been stated by some as having the potential to “change the landscape” of the treatment for lung cancer. Another antibody, shown to achieve a substantial response rate also in patients with non-small cell lung cancer, is currently in clinical trial for many types of cancers. In addition, combination therapy (anti-CTLA-4 plus anti-PD-1) has been shown to dramatically improve the long-term survival rates in cancer patients.
This is an exciting time in our fight against cancer. The discoveries by Dr. Allison and Dr. Honjo have spurred additional development of therapeutic approaches along the line of immunotherapy and brought new hope that many types of cancers can be cured.
In addition, dysregulation in immune checkpoint pathways may be intimately involved in other illnesses, such as allergy, infectious diseases, and autoimmune diseases. Thus, the approach of targeting immune stimulatory and inhibitory molecules also promises to lead to the development of new therapies for these diseases.
Dr. Allison’s and Dr. Honjo’s discoveries have opened a new therapeutic era in medicine.
Supplementary figure:
unleashes immune system to attack cancer cells
Dr. Samuel Yin, founder of the Tang Prize, is currently chairman of the Ruentex Group and chief development officer, chief technology officer, and chief engineer of Ruentex Construction & Development. He is also an adjunct professor in the department of civil engineering at National Taiwan University and a professor at Peking University, where he advises PhD students.
Dr. Yin read history at Chinese Culture University. He received a master’s degree in business administration at National Taiwan University and a doctorate in business administration at National Chengchi University.
In addition to his academic background in the humanities and business administration, Dr. Yin’s great interest in and devotion to interdisciplinary studies have made him an award-winning civil engineer and educator.
In 2004, Dr. Yin was named fellow of the Chinese Institute of Civil and Hydraulic Engineering. In 2008, he was invited to join Russia’s International Academy of Engineering and also awarded the Engineering Prowess Medal, the academy’s highest honour. In 2010, Dr. Yin received the Henry L. Michel Award for Industry Advancement of Research by the prestigious American Society of Civil Engineers (ASCE) for his contribution in the area of construction technology research. He was the first person without an academic background in engineering to receive the award.
Driven by a firm belief that he should give back to the society that has enabled him to achieve so much, Dr. Yin has been investing in philanthropy and education for a long time, in the hope of creating a positive force in society and making a better world.
Dr. Yin’s biggest dream was to set up an international award. He has long had great respect and admiration for the Nobel Prize, so he established an award modeled on the Nobel. The Tang Prize rewards excellent research in the areas of Sustainable Development, Biopharmaceutical Science, Sinology (excluding literary works), and Rule of Law. Dr. Yin hopes to encourage experts to dedicate themselves to innovative research in these fields and to spur human development with first-class research.
Dr. Yin’s relentless enthusiasm for philanthropy was instilled through his upbringing, particularly the example set by his late father Yin Shu-Tien. Dr. Yin established a foundation in memory of his grandfather, Yin Xun-Ruo, to provide scholarships to students of families originating in Shandong Province to study Chinese literature and history. When Yin senior passed away, Dr. Yin also set up the Kwang-Hua Education Foundation to help with China’s higher education programs.
In the past few years, Dr. Yin has set up a number of foundations to serve people on both sides of the Taiwan Strait and to foster more talented people for the nation (the Yin Xun-Ruo Educational Foundation, the Yin Shu-Tien Medical Foundation, the Kwang-Hua Education Foundation, and the Guanghua School of Management of Peking University). In 2012, Dr. Yin set up a global award, the Tang Prize, to spread his philanthropy across the world.
Summary of Translational Medicine – e-Series A: Cardiovascular Diseases, Volume Four – Part 1
Author and Curator: Larry H Bernstein, MD, FCAP
and
Curator: Aviva Lev-Ari, PhD, RN
Article ID #135: Summary of Translational Medicine – e-Series A: Cardiovascular Diseases, Volume Four – Part 1. Published on 4/28/2014
WordCloud Image Produced by Adam Tubman
Part 1 of Volume 4 in the e-series A: Cardiovascular Diseases and Translational Medicine, provides a foundation for grasping a rapidly developing surging scientific endeavor that is transcending laboratory hypothesis testing and providing guidelines to:
Target genomes and multiple nucleotide sequences involved in either coding or in regulation that might have an impact on complex diseases, not necessarily genetic in nature.
Target signaling pathways that are demonstrably maladjusted, activated or suppressed in many common and complex diseases, or in their progression.
Enable a reduction in failure due to toxicities in the later stages of clinical drug trials as a result of this science-based understanding.
Enable a reduction in complications from the improvement of machanical devices that have already had an impact on the practice of interventional procedures in cardiology, cardiac surgery, and radiological imaging, as well as improving laboratory diagnostics at the molecular level.
Enable the discovery of new drugs in the continuing emergence of drug resistance.
Enable the construction of critical pathways and better guidelines for patient management based on population outcomes data, that will be critically dependent on computational methods and large data-bases.
What has been presented can be essentially viewed in the following Table:
Summary Table for TM – Part 1
There are some developments that deserve additional development:
1. The importance of mitochondrial function in the activity state of the mitochondria in cellular work (combustion) is understood, and impairments of function are identified in diseases of muscle, cardiac contraction, nerve conduction, ion transport, water balance, and the cytoskeleton – beyond the disordered metabolism in cancer. A more detailed explanation of the energetics that was elucidated based on the electron transport chain might also be in order.
2. The processes that are enabling a more full application of technology to a host of problems in the environment we live in and in disease modification is growing rapidly, and will change the face of medicine and its allied health sciences.
Electron Transport and Bioenergetics
Deferred for metabolomics topic
Synthetic Biology
Introduction to Synthetic Biology and Metabolic Engineering
http://www.ibiology.org Lecturers generously donate their time to prepare these lectures. The project is funded by NSF and NIGMS, and is supported by the ASCB and HHMI.
Dr. Prather explains that synthetic biology involves applying engineering principles to biological systems to build “biological machines”.
Dr. Prather has received numerous awards both for her innovative research and for excellence in teaching. Learn more about how Kris became a scientist at
Prather 1: Synthetic Biology and Metabolic Engineering 2/6/14IntroductionLecture Overview In the first part of her lecture, Dr. Prather explains that synthetic biology involves applying engineering principles to biological systems to build “biological machines”. The key material in building these machines is synthetic DNA. Synthetic DNA can be added in different combinations to biological hosts, such as bacteria, turning them into chemical factories that can produce small molecules of choice. In Part 2, Prather describes how her lab used design principles to engineer E. coli that produce glucaric acid from glucose. Glucaric acid is not naturally produced in bacteria, so Prather and her colleagues “bioprospected” enzymes from other organisms and expressed them in E. coli to build the needed enzymatic pathway. Prather walks us through the many steps of optimizing the timing, localization and levels of enzyme expression to produce the greatest yield. Speaker Bio: Kristala Jones Prather received her S.B. degree from the Massachusetts Institute of Technology and her PhD at the University of California, Berkeley both in chemical engineering. Upon graduation, Prather joined the Merck Research Labs for 4 years before returning to academia. Prather is now an Associate Professor of Chemical Engineering at MIT and an investigator with the multi-university Synthetic Biology Engineering Reseach Center (SynBERC). Her lab designs and constructs novel synthetic pathways in microorganisms converting them into tiny factories for the production of small molecules. Dr. Prather has received numerous awards both for her innovative research and for excellence in teaching.
Calcium Cycling in Synthetic and Contractile Phasic or Tonic Vascular Smooth Muscle Cells
in INTECH
Current Basic and Pathological Approaches to
the Function of Muscle Cells and Tissues – From Molecules to HumansLarissa Lipskaia, Isabelle Limon, Regis Bobe and Roger Hajjar
Additional information is available at the end of the chapter http://dx.doi.org/10.5772/48240
1. Introduction
Calcium ions (Ca ) are present in low concentrations in the cytosol (~100 nM) and in high concentrations (in mM range) in both the extracellular medium and intracellular stores (mainly sarco/endo/plasmic reticulum, SR). This differential allows the calcium ion messenger that carries information
as diverse as contraction, metabolism, apoptosis, proliferation and/or hypertrophic growth. The mechanisms responsible for generating a Ca signal greatly differ from one cell type to another.
In the different types of vascular smooth muscle cells (VSMC), enormous variations do exist with regard to the mechanisms responsible for generating Ca signal. In each VSMC phenotype (synthetic/proliferating and contractile [1], tonic or phasic), the Ca signaling system is adapted to its particular function and is due to the specific patterns of expression and regulation of Ca.
For instance, in contractile VSMCs, the initiation of contractile events is driven by mem- brane depolarization; and the principal entry-point for extracellular Ca is the voltage-operated L-type calcium channel (LTCC). In contrast, in synthetic/proliferating VSMCs, the principal way-in for extracellular Ca is the store-operated calcium (SOC) channel.
Whatever the cell type, the calcium signal consists of limited elevations of cytosolic free calcium ions in time and space. The calcium pump, sarco/endoplasmic reticulum Ca ATPase (SERCA), has a critical role in determining the frequency of SR Ca release by upload into the sarcoplasmic
sensitivity of SR calcium channels, Ryanodin Receptor, RyR and Inositol tri-Phosphate Receptor, IP3R.
Synthetic VSMCs have a fibroblast appearance, proliferate readily, and synthesize increased levels of various extracellular matrix components, particularly fibronectin, collagen types I and III, and tropoelastin [1].
Contractile VSMCs have a muscle-like or spindle-shaped appearance and well-developed contractile apparatus resulting from the expression and intracellular accumulation of thick and thin muscle filaments [1].
Schematic representation of Calcium Cycling in Contractile and Proliferating VSMCs
Figure 1. Schematic representation of Calcium Cycling in Contractile and Proliferating VSMCs.
Left panel: schematic representation of calcium cycling in quiescent /contractile VSMCs. Contractile re-sponse is initiated by extracellular Ca influx due to activation of Receptor Operated Ca (through phosphoinositol-coupled receptor) or to activation of L-Type Calcium channels (through an increase in luminal pressure). Small increase of cytosolic due IP3 binding to IP3R (puff) or RyR activation by LTCC or ROC-dependent Ca influx leads to large SR Ca IP3R or RyR clusters (“Ca -induced Ca SR calcium pumps (both SERCA2a and SERCA2b are expressed in quiescent VSMCs), maintaining high concentration of cytosolic Ca and setting the sensitivity of RyR or IP3R for the next spike.
Contraction of VSMCs occurs during oscillatory Ca transient.
Middle panel: schematic representa tion of atherosclerotic vessel wall. Contractile VSMC are located in the media layer, synthetic VSMC are located in sub-endothelial intima.
Right panel: schematic representation of calcium cycling in quiescent /contractile VSMCs. Agonist binding to phosphoinositol-coupled receptor leads to the activation of IP3R resulting in large increase in cytosolic Ca calcium pumps (only SERCA2b, having low turnover and low affinity to Ca depletion leads to translocation of SR Ca sensor STIM1 towards PM, resulting in extracellular Ca influx though opening of Store Operated Channel (CRAC). Resulted steady state Ca transient is critical for activation of proliferation-related transcription factors ‘NFAT).
Abbreviations: PLC – phospholipase C; PM – plasma membrane; PP2B – Ca /calmodulin-activated protein phosphatase 2B (calcineurin); ROC- receptor activated channel; IP3 – inositol-1,4,5-trisphosphate, IP3R – inositol-1,4,5- trisphosphate receptor; RyR – ryanodine receptor; NFAT – nuclear factor of activated T-lymphocytes; VSMC – vascular smooth muscle cells; SERCA – sarco(endo)plasmic reticulum Ca sarcoplasmic reticulum.
Time for New DNA Synthesis and Sequencing Cost Curves
By Rob Carlson
I’ll start with the productivity plot, as this one isn’t new. For a discussion of the substantial performance increase in sequencing compared to Moore’s Law, as well as the difficulty of finding this data, please see this post. If nothing else, keep two features of the plot in mind: 1) the consistency of the pace of Moore’s Law and 2) the inconsistency and pace of sequencing productivity. Illumina appears to be the primary driver, and beneficiary, of improvements in productivity at the moment, especially if you are looking at share prices. It looks like the recently announced NextSeq and Hiseq instruments will provide substantially higher productivities (hand waving, I would say the next datum will come in another order of magnitude higher), but I think I need a bit more data before officially putting another point on the plot.
cost-of-oligo-and-gene-synthesis
Illumina’s instruments are now responsible for such a high percentage of sequencing output that the company is effectively setting prices for the entire industry. Illumina is being pushed by competition to increase performance, but this does not necessarily translate into lower prices. It doesn’t behoove Illumina to drop prices at this point, and we won’t see any substantial decrease until a serious competitor shows up and starts threatening Illumina’s market share. The absence of real competition is the primary reason sequencing prices have flattened out over the last couple of data points.
Note that the oligo prices above are for column-based synthesis, and that oligos synthesized on arrays are much less expensive. However, array synthesis comes with the usual caveat that the quality is generally lower, unless you are getting your DNA from Agilent, which probably means you are getting your dsDNA from Gen9.
Note also that the distinction between the price of oligos and the price of double-stranded sDNA is becoming less useful. Whether you are ordering from Life/Thermo or from your local academic facility, the cost of producing oligos is now, in most cases, independent of their length. That’s because the cost of capital (including rent, insurance, labor, etc) is now more significant than the cost of goods. Consequently, the price reflects the cost of capital rather than the cost of goods. Moreover, the cost of the columns, reagents, and shipping tubes is certainly more than the cost of the atoms in the sDNA you are ostensibly paying for. Once you get into longer oligos (substantially larger than 50-mers) this relationship breaks down and the sDNA is more expensive. But, at this point in time, most people aren’t going to use longer oligos to assemble genes unless they have a tricky job that doesn’t work using short oligos.
Looking forward, I suspect oligos aren’t going to get much cheaper unless someone sorts out how to either 1) replace the requisite human labor and thereby reduce the cost of capital, or 2) finally replace the phosphoramidite chemistry that the industry relies upon.
IDT’s gBlocks come at prices that are constant across quite substantial ranges in length. Moreover, part of the decrease in price for these products is embedded in the fact that you are buying smaller chunks of DNA that you then must assemble and integrate into your organism of choice.
Someone who has purchased and assembled an absolutely enormous amount of sDNA over the last decade, suggested that if prices fell by another order of magnitude, he could switch completely to outsourced assembly. This is a potentially interesting “tipping point”. However, what this person really needs is sDNA integrated in a particular way into a particular genome operating in a particular host. The integration and testing of the new genome in the host organism is where most of the cost is. Given the wide variety of emerging applications, and the growing array of hosts/chassis, it isn’t clear that any given technology or firm will be able to provide arbitrary synthetic sequences incorporated into arbitrary hosts.
Dr. Jon Rowley and Dr. Uplaksh Kumar, Co-Founders of RoosterBio, Inc., a newly formed biotech startup located in Frederick, are paving the way for even more innovation in the rapidly growing fields of Synthetic Biology and Regenerative Medicine. Synthetic Biology combines engineering principles with basic science to build biological products, including regenerative medicines and cellular therapies. Regenerative medicine is a broad definition for innovative medical therapies that will enable the body to repair, replace, restore and regenerate damaged or diseased cells, tissues and organs. Regenerative therapies that are in clinical trials today may enable repair of damaged heart muscle following heart attack, replacement of skin for burn victims, restoration of movement after spinal cord injury, regeneration of pancreatic tissue for insulin production in diabetics and provide new treatments for Parkinson’s and Alzheimer’s diseases, to name just a few applications.
While the potential of the field is promising, the pace of development has been slow. One main reason for this is that the living cells required for these therapies are cost-prohibitive and not supplied at volumes that support many research and product development efforts. RoosterBio will manufacture large quantities of standardized primary cells at high quality and low cost, which will quicken the pace of scientific discovery and translation to the clinic. “Our goal is to accelerate the development of products that incorporate living cells by providing abundant, affordable and high quality materials to researchers that are developing and commercializing these regenerative technologies” says Dr. Rowley
NHMU Lecture featuring – J. Craig Venter, Ph.D. Founder, Chairman, and CEO – J. Craig Venter Institute; Co-Founder and CEO, Synthetic Genomics Inc.
J. Craig Venter, Ph.D., is Founder, Chairman, and CEO of the J. Craig Venter Institute (JVCI), a not-for-profit, research organization dedicated to human, microbial, plant, synthetic and environmental research. He is also Co-Founder and CEO of Synthetic Genomics Inc. (SGI), a privately-held company dedicated to commercializing genomic-driven solutions to address global needs.
In 1998, Dr. Venter founded Celera Genomics to sequence the human genome using new tools and techniques he and his team developed. This research culminated with the February 2001 publication of the human genome in the journal, Science. Dr. Venter and his team at JVCI continue to blaze new trails in genomics. They have sequenced and a created a bacterial cell constructed with synthetic DNA, putting humankind at the threshold of a new phase of biological research. Whereas, we could previously read the genetic code (sequencing genomes), we can now write the genetic code for designing new species.
The science of synthetic genomics will have a profound impact on society, including new methods for chemical and energy production, human health and medical advances, clean water, and new food and nutritional products. One of the most prolific scientists of the 21st century for his numerous pioneering advances in genomics, he guides us through this emerging field, detailing its origins, current challenges, and the potential positive advances.
His work on synthetic biology truly embodies the theme of “pushing the boundaries of life.” Essentially, Venter is seeking to “write the software of life” to create microbes designed by humans rather than only through evolution. The potential benefits and risks of this new technology are enormous. It also requires us to examine, both scientifically and philosophically, the question of “What is life?”
J Craig Venter wants to digitize DNA and transmit the signal to teleport organisms
A technology trend analyst offers an overview of synthetic biology, its potential applications, obstacles to its development, and prospects for public approval.
In addition to boosting the economy, synthetic biology projects currently in development could have profound implications for the future of manufacturing, sustainability, and medicine.
Before society can fully reap the benefits of synthetic biology, however, the field requires development and faces a series of hurdles in the process. Do researchers have the scientific know-how and technical capabilities to develop the field?
Biology + Engineering = Synthetic Biology
Bioengineers aim to build synthetic biological systems using compatible standardized parts that behave predictably. Bioengineers synthesize DNA parts—oligonucleotides composed of 50–100 base pairs—which make specialized components that ultimately make a biological system. As biology becomes a true engineering discipline, bioengineers will create genomes using mass-produced modular units similar to the microelectronics and computer industries.
Currently, bioengineering projects cost millions of dollars and take years to develop products. For synthetic biology to become a Schumpeterian revolution, smaller companies will need to be able to afford to use bioengineering concepts for industrial applications. This will require standardized and automated processes.
A major challenge to developing synthetic biology is the complexity of biological systems. When bioengineers assemble synthetic parts, they must prevent cross talk between signals in other biological pathways. Until researchers better understand these undesired interactions that nature has already worked out, applications such as gene therapy will have unwanted side effects. Scientists do not fully understand the effects of environmental and developmental interaction on gene expression. Currently, bioengineers must repeatedly use trial and error to create predictable systems.
Similar to physics, synthetic biology requires the ability to model systems and quantify relationships between variables in biological systems at the molecular level.
The second major challenge to ensuring the success of synthetic biology is the development of enabling technologies. With genomes having billions of nucleotides, this requires fast, powerful, and cost-efficient computers. Moore’s law, named for Intel co-founder Gordon Moore, posits that computing power progresses at a predictable rate and that the number of components in integrated circuits doubles each year until its limits are reached. Since Moore’s prediction, computer power has increased at an exponential rate while pricing has declined.
DNA sequencers and synthesizers are necessary to identify genes and make synthetic DNA sequences. Bioengineer Robert Carlson calculated that the capabilities of DNA sequencers and synthesizers have followed a pattern similar to computing. This pattern, referred to as the Carlson Curve, projects that scientists are approaching the ability to sequence a human genome for $1,000, perhaps in 2020. Carlson calculated that the costs of reading and writing new genes and genomes are falling by a factor of two every 18–24 months. (see recent Carlson comment on requirement to read and write for a variety of limiting conditions).
Startup to Strengthen Synthetic Biology and Regenerative Medicine Industries with Cutting Edge Cell Products
Synthetic Biology: On Advanced Genome Interpretation for Gene Variants and Pathways: What is the Genetic Base of Atherosclerosis and Loss of Arterial Elasticity with Aging
Futurists have touted the twenty-first century as the century of biology based primarily on the promise of genomics. Medical researchers aim to use variations within genes as biomarkers for diseases, personalized treatments, and drug responses. Currently, we are experiencing a genomics bubble, but with advances in understanding biological complexity and the development of enabling technologies, synthetic biology is reviving optimism in many fields, particularly medicine.
Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman,and his most recent book is The Secret Anarchy of Science.
The basic idea is that we take an organism – a bacterium, say – and re-engineer its genome so that it does something different. You might, for instance, make it ingest carbon dioxide from the atmosphere, process it and excrete crude oil.
That project is still under construction, but others, such as using synthesised DNA for data storage, have already been achieved. As evolution has proved, DNA is an extraordinarily stable medium that can preserve information for millions of years. In 2012, the Harvard geneticist George Church proved its potential by taking a book he had written, encoding it in a synthesised strand of DNA, and then making DNA sequencing machines read it back to him.
When we first started achieving such things it was costly and time-consuming and demanded extraordinary resources, such as those available to the millionaire biologist Craig Venter. Venter’s team spent most of the past two decades and tens of millions of dollars creating the first artificial organism, nicknamed “Synthia”. Using computer programs and robots that process the necessary chemicals, the team rebuilt the genome of the bacterium Mycoplasma mycoides from scratch. They also inserted a few watermarks and puzzles into the DNA sequence, partly as an identifying measure for safety’s sake, but mostly as a publicity stunt.
What they didn’t do was redesign the genome to do anything interesting. When the synthetic genome was inserted into an eviscerated bacterial cell, the new organism behaved exactly the same as its natural counterpart. Nevertheless, that Synthia, as Venter put it at the press conference to announce the research in 2010, was “the first self-replicating species we’ve had on the planet whose parent is a computer” made it a standout achievement.
Today, however, we have entered another era in synthetic biology and Venter faces stiff competition. The Steve Jobs to Venter’s Bill Gates is Jef Boeke, who researches yeast genetics at New York University.
Boeke wanted to redesign the yeast genome so that he could strip out various parts to see what they did. Because it took a private company a year to complete just a small part of the task, at a cost of $50,000, he realised he should go open-source. By teaching an undergraduate course on how to build a genome and teaming up with institutions all over the world, he has assembled a skilled workforce that, tinkering together, has made a synthetic chromosome for baker’s yeast.
Stepping into DIYbio and Synthetic Biology at ScienceHack
We got a crash course on genetics and protein pathways, and then set out to design and build our own pathways using both the “Genomikon: Violacein Factory” kit and Synbiota platform. With Synbiota’s software, we dragged and dropped the enzymes to create the sequence that we were then going to build out. After a process of sketching ideas, mocking up pathways, and writing hypotheses, we were ready to start building!
The night stretched long, and at midnight we were forced to vacate the school. Not quite finished, we loaded our delicate bacteria, incubator, and boxes of gloves onto the bus and headed back to complete our bacterial transformation in one of our hotel rooms. Jammed in between the beds and the mini-fridge, we heat-shocked our bacteria in the hotel ice bucket. It was a surreal moment.
While waiting for our bacteria, we held an “unconference” where we explored bioethics, security and risk related to synthetic biology, 3D printing on Mars, patterns in juggling (with live demonstration!), and even did a Google Hangout with Rob Carlson. Every few hours, we would excitedly check in on our bacteria, looking for bacterial colonies and the purple hue characteristic of violacein.
Most impressive was the wildly successful and seamless integration of a diverse set of people: in a matter of hours, we were transformed from individual experts and practitioners in assorted fields into cohesive and passionate teams of DIY biologists and science hackers. The ability of everyone to connect and learn was a powerful experience, and over the course of just one weekend we were able to challenge each other and grow.
Returning to work on Monday, we were hungry for more. We wanted to find a way to bring the excitement and energy from the weekend into the studio and into the projects we’re working on. It struck us that there are strong parallels between design and DIYbio, and we knew there was an opportunity to bring some of the scientific approaches and curiosity into our studio.
Prologue to Cancer – e-book Volume One – Where are we in this journey?
Author and Curator: Larry H. Bernstein, MD, FCAP
Article ID #128: Prologue to Cancer – e-book Volume One – Where are we in this journey? Published on 4/13/2014
WordCloud Image Produced by Adam Tubman
Consulting Reviewer and Contributor: Jose Eduardo de Salles Roselino, MD
LH Bernstein
LES Roselino
This is a preface to the fourth in the ebook series of Leaders in Pharmaceutical Intelligence, a collaboration of experienced doctorate medical and pharmaceutical professionals. The topic is of great current interest, and it entails a significant part of current medical expenditure by a group of neoplastic diseases that may develop at different periods in life, and have come to supercede infections or even eventuate in infectious disease as an end of life event. The articles presented are a collection of the most up-to-date accounts of the state of a now rapidly emerging field of medical research that has benefitted enormously by progress in immunodiagnostics, radiodiagnostics, imaging, predictive analytics, genomic and proteomic discovery subsequent to the completion of the Human Genome Project, advances in analytic methods in qPCR, gene sequencing, genome mapping, signaling pathways, exome identification, identification of therapeutic targets in inhibitors, activators, initiators in the progression of cell metabolism, carcinogenesis, cell movement, and metastatic potential. This story is very complicated because we are engaged in trying to evoke from what we would like to be similar clinical events, dissimilar events in their expression and classification, whether they are within the same or different anatomic class. Thus, we are faced with constructing an objective evidence-based understanding requiring integration of several disciplinary approaches to see a clear picture. The failure to do so creates a high risk of failure in biopharmaceutical development.
The chapters that follow cover novel and important research and development in cancer related research, development, diagnostics and treatment, and in balance, present a substantial part of the tumor landscape, with some exceptions. Will there ever be a unifying concept, as might be hoped for? I certainly can’t see any such prediction on the horizon. Part of the problem is that disease classification is a human construct to guide us, and so are treatments that have existed and are reexamined for over 2,000 years. In that time, we have changed, our afflictions have been modified, and our environment has changed with respect to the microorganisms within and around us, viruses, the soil, and radiation exposure, and the impacts of war and starvation, and access to food. The outline has been given. Organic and inorganic chemistry combined with physics has given us a new enterprise in biosynthetics that is and will change our world. But let us keep in mind that this is a human construct, just as drug target development is such a construct, workable with limitations.
What Molecular Biology Gained from Physics
We need greater clarity and completeness in defining the carcinogenetic process. It is the beginning, but not the end. But we must first examine the evolution of the scientific structure that leads to our present understanding. This was preceded by the studies of anatomy, physiology, and embryology that had to occur as a first step, which was followed by the researches into bacteriology, fungi, sea urchins and the evolutionary creatures that could be studied having more primary development in scale. They are still major objects of study, with the expectation that we can derive lessons about comparative mechanisms that have been passed on through the ages and have common features with man. This became the serious intent of molecular biology, the discipline that turned to find an explanation for genetics, and to carry out controlled experiments modelled on the discipline that already had enormous success in physics, mathematics, and chemistry. In 1900, when Max Planck hypothesized that the frequency of light emitted by the black body depended on the frequency of the oscillator that emitted it, it had important ramifications for chemistry and biology (See Appendix II and Footnote 1, Planck equation, energy and oscillation). The leading idea is to search below the large-scale observations of classical biology.
The central dogma of molecular biology where genetic material is transcribed into RNA and then translated into protein, provides a starting point, but the construct is undergoing revision in light of emerging novel roles for RNA and signaling pathways. The term, coined by Warren Weaver (director of Natural Sciences for the Rockefeller Foundation), who observed an emergence of significant change given recent advances in fields such as X-ray crystallography. Molecular biology also plays important role in understanding formations, actions, regulations of various parts of cellswhich can be used efficiently for targeting new drugs, diagnosis of disease, physiology of the Cell. The Nobel Prize in Physiology or Medicine in 1969 was shared by Max Delbrück, Alfred D. Hershey, Salvador E. Luria, whose work with viral replication gave impetus to the field. Delbruck was a physicist who trained in Copenhagen under Bohr, and specifically committed himself to a rigor in biology, as was in physics.
Dorothy Hodgkin protein crystallography
Rosalind Franlin crystallographer double helix
Max Delbruck molecular biology
Max Planck Quantum Physics
We then stepped back from classical (descriptive) physiology, with the endless complexity, to molecular biology. This led us to the genetic code, with a double helix model. It has recently been found insufficiently explanatory, with the recent construction of triplex and quadruplex models. They have a potential to account for unaccounted for building blocks, such as inosine, and we don’t know whether more than one model holds validity under different conditions . The other major field of development has been simply unaccounted for in the study of proteomics, especially in protein-protein interactions, and in the energetics of protein conformation, first called to our attention by the work of Jacob, Monod, and Changeux (See Footnote 2). Proteins are not just rigid structures stamped out by the monotonously simple DNA to RNA to protein concept. Nothing is ever quite so simple. Just as there are epigenetic events, there are posttranslational events, and yet more.
JP Changeux
The Emergence of Molecular Biology
I now return the discussion to the topic of medicine, the emergence of molecular biology and the need for convergence with biochemistry in the mid-20th century. Jose Eduardo de Salles Roselino recalls “I was previously allowed to make of the conformational energy as made by R Marcus in his Nobel lecture revised (J. of Electroanalytical Chemistry 438:(1997) p251-259. (See Footnote 1) His description of the energetic coordinates of a landscape of a chemical reaction is only a two-dimensional cut of what in fact is a volcano crater (in three dimensions) (each one varies but the sum of the two is constant. Solvational+vibrational=100% in ordinate) nuclear coordinates in abcissa. In case we could represent it by research methods that allow us to discriminate in one by one degree of different pairs of energy, we would most likely have 360 other similar representations of the same phenomenon. The real representation would take into account all those 360 representations together. In case our methodology was not that fine, for instance it discriminates only differences of minimal 10 degrees in 360 possible, will have 36 partial representations of something that to be perfectly represented will require all 36 being taken together. Can you reconcile it with ATGC? Yet, when complete genome sequences were presented they were described as though we will know everything about this living being. The most important problems in biology will be viewed by limited vision always and the awareness of this limited is something we should acknowledge and teach it. Therefore, our knowledge is made up of partial representations. If we had the entire genome data for the most intricate biological problems, they are still not amenable to this level of reductionism. But going from general views of signals andsymptoms we could get to the most detailed molecular view and in this case genome provides an anchor.”
“Warburg Effect” describes the preference of glycolysis and lactic acid fermentation rather than oxidative phosphorylation for energy production in cancer cells. Mitochondrial metabolism is an important and necessary component in the functioning and maintenance of the cell, and accumulating evidence suggests that dysfunction of mitochondrial metabolism plays a role in cancer. Progress has demonstrated the mechanisms of the mitochondrial metabolism-to-glycolysis switch in cancer development and how to target this metabolic switch.
glycolysis
Otto Warburg
Louis Pasteur
The expression “Pasteur effect” was coined by Warburg when inspired by Pasteur’s findings in yeast cells, when he investigated this metabolic observation (Pasteur effect) in cancer cells. In yeast cells, Pasteur had found that the velocity of sugar used was greatly reduced in presence of oxygen. Not to be confused, in the “Crabtree effect”, the velocity of sugar metabolism was greatly increased, a reversal, when yeast cells were transferred from the aerobic to an anaerobic condition. Thus, the velocity of sugar metabolism of yeast cells was shown to be under metabolic regulatory control in response to change in environmental oxygen conditions in growth. Warburg had to verify whether cancer cells and tissue related normal mammalian cells also have a similar control mechanism. He found that this control was also found in normal cells studied, but was absent in cancer cells. Strikingly, cancer cells continue to have higher anaerobic gycolysis despite the presence of oxygen in their culture media (See Footnote 3).
Taking this a step further, food is digested and supplied to cells In vertebrates mainly in the form of glucose, which is metabolized producing Adenosine Triphosphate (ATP) by two pathways. Glycolysis, occurs via anaerobic metabolism in the cytoplasm, and is of major significance for making ATP quickly, but in a minuscule amount (2 molecules). In the presence of oxygen, the breakdown process continues in the mitochondria via the Krebs’s cycle coupled with oxidative phosphorylation, which is more efficient for ATP production (36 molecules). Cancer cells seem to depend on glycolysis. In the 1920s, Otto Warburg first proposed that cancer cells show increased levels of glucose consumption and lactate fermentation even in the presence of ample oxygen (known as “Warburg Effect”). Based on this theory, oxidative phosphorylation switches to glycolysis which promotes the proliferation of cancer cells. Many studies have demonstrated glycolysis as the main metabolic pathway in cancer cells.
Albert Szent Gyogy (Warburg’s student) and Otto Meyerhof both studied striated skeletal muscle metabolism invertebrates, and they found those changes observed in yeast by Pasteur. The description of the anaerobic pathway was largely credited to Emden and Meyerhof. Whenever there is increase in muscle work, energy need is above what can be provided by blood supply, the cell metabolism changes from aerobic (where Acetyl CoA provides the chemical energy for aerobic production of ATP) to anaerobic metabolism of glucose. In this condition, glucose is obtained directly from its muscle glycogen stores (not from hepatic glycogenolysis). This is the sole source of chemical energy that is independent of oxygen supplied to the cell. It is a physiological change on muscle metabolism that favors autonomy. It does not depend upon the blood oxygen for aerobic metabolim or blood sources of carbon metabolites borne out from adipose tissue (free fatty acids) or muscle proteins (branched chain amino acids), or vascular delivery of glucose. On that condition, the muscle can perform contraction by its internal source of ATP and uses conversion of pyruvate to lactate in order to regenerate much-needed NAD (by hydride transfer from pyruvate) as a replacement for this mitochondrial function. This regulatory change, keeps glycolysis going at fast rate in order to meet ATP needs of the cell under low yield condition (only two or three ATP for each glucose converted into two lactate molecules). Therefore, it cannot last for long periods of time. This regulatory metabolic change is made in seconds, minutes and therefore happens with the proteins that are already presented in the cell. It does not requires the effect of transcription factors and/or changes in gene expression (See Footnote 1, 2).
In other types mammalian cells, like those from the lens of the eye (86% gycolysis + pentose shunt), and red blood cells (RBC)[both lacking mitochondria], and also in the deep medullary layer of the kidneys, for lack of mitochondria in the first two cases and normally reduced blood perfusion in the third – A condition required for the counter current mechanism and our ability to concentrate urine also have, permanent higher anaerobic metabolism. In the case of RBC, it includes the ability to produce in a shunt of glycolytic pathway 2,3 diphospho- glycerate that is required to place the hemogloblin macromolecule in an unstable equilibrium between its two forms (R and T – Here presented as simplified accordingly to the model of Monod, Wyman and Changeux. The final model would be even much complex (see for instance, H-W and K review Nature 2007 vol 450: p 964-972 )
Any tissue under a condition of ischemia that is required for some medical procedures (open heart surgery, organ transplants, etc) displays this fast regulatory mechanism (See Footnote 1, 2). A display of these regulatory metabolic changes can be seen in: Cardioplegia: the protection of the myocardium during open heart surgery: a review. D. J. Hearse J. Physiol., Paris, 1980, 76, 751-756 (Fig 1). The following points are made:
1- It is a fast regulatory response. Therefore, no genetic mechanism can be taken into account.
2- It moves from a reversible to an irreversible condition, while the cells are still alive. Death can be seen at the bottom end of the arrow. Therefore, it cannot be reconciled with some of the molecular biology assumptions:
A- The gene and genes reside inside the heart muscle cells but, in order to preserve intact, the source of coded genetic information that the cell reads and transcribes, DNA must be kept to a minimal of chemical reactivity.
B- In case sequence determines conformation, activity and function , elevated potassium blood levels could not cause cardiac arrest.
In comparison with those conditions here presented, cancer cells keep the two metabolic options for glucose metabolism at the same time. These cells can use glucose that our body provides to them or adopt temporarily, an independent metabolic form without the usual normal requirement of oxygen (one or another form for ATP generation). ATP generation is here, an over-simplification of the metabolic status since the carbon flow for building blocks must also be considered and in this case oxidative metabolism of glucose in cancer cells may be viewed as a rich source of organic molecules or building blocks that dividing cells always need.
JES Roselino has conjectured that “most of the Krebs cycle reaction works as ideal reversible thermodynamic systems that can supply any organic molecule that by its absence could prevent cell duplication.” In the vision of Warburg, cancer cells have a defect in Pasteur-effect metabolic control. In case it was functioning normally, it will indicate which metabolic form of glucose metabolism is adequate for each condition. What more? Cancer cells lack differentiated cell function. Any role for transcription factors must be considered as the role of factors that led to the stable phenotypic change of cancer cells. The failure of Pasteur effect must be searched for among the fast regulatory mechanisms that aren’t dependent on gene expression (See Footnote 3).
Extending the thoughts of JES Roselino (Hepatology 1992;16: 1055-1060), reduced blood flow caused by increased hydrostatic pressure in extrahepatic cholestasis decreases mitochondrial function (quoted in Hepatology) and as part of Pasteur effect normal response, increased glycolysis in partial and/or functional anaerobiosis and therefore blocks the gluconeogenic activity of hepatocytes that requires inhibited glycolysis. In this case, a clear energetic link can be perceived between the reduced energetic supply and the ability to perform differentiated hepatic function (gluconeogenesis). In cancer cells, the action of transcription factors that can be viewed as different ensembles of kaleidoscopic pieces (with changing activities as cell conditions change) are clearly linked to the new stable phenotype. In relation to extrahepatic cholestasis mentioned above it must be reckoned that in case a persistent chronic condition is studied a secondary cirrhosis is installed as an example of persistent stable condition, difficult to be reversed and without the requirement for a genetic mutation. (See Footnote 4).
The Rejection of Complexity
Most of our reasoning about genes was derived from scientific work in microorganisms. These works have provided great advances in biochemistry.
double helix
Triple helix
formation of triple helix
1- The “Gelehrter idea”: No matter what you are doing you will always be better off, in case you have a gene (In chapter 7 Principles of Medical Genetics Gelehrter and Collins Williams & Wilkins 1990).
2- The idea that everything could be found following one gene one enzyme relationship that works fine for our understanding of the metabolism, in all biological problems.
3- The idea that everything that explains biochemistry in microorganisms explains also for every living being (J Nirenberg).
4- The idea that biochemistry may not require that time should be also taken into account. Time must be considered only for genetic and biological evolution studies (S Luria. In Life- The unfinished experiment 1977 C Scribner´s sons NY).
5- Finally, the idea that everything in biology, could be found in the genome. Since all information in biology goes from DNA through RNA to proteins. Alternatively, are in the DNA, in case the strict line that includes RNA is not included.
This last point can be accepted in case it is considered that ALL GENETIC information is in our DNA. Genetics as part of life and not as its total expression.
For example, when our body is informed that the ambient temperature is too low or alternatively is too high, our body is receiving an information that arrives from our environment. This external information will affect our proteins and eventually, in case of longer periods in a new condition will cause adaptive response that may include conformational changes in transcription factors (proteins) that will also, produce new readings on the DNA. However, it is an information that moves from outside, to proteins and not from DNA to proteins. The last pathway, when transcription factors change its conformation and change DNA reading will follow the dogmatic view as an adaptive response (See Footnotes 1-3).
However, in case, time is taken into account, the first reactions against cold or warmer temperatures will be the ones that happen through change in protein conformation, activities and function before any change in gene expression can be noticed at protein level. These fast changes, in seconds, minutes cannot be explained by changes in gene expression and are strongly linked to what is needed for the maintenance of life.
“It is possible”, says Roselino, “desirable, to explain all these fast biochemical responses to changes in a living being condition as the sound foundation of medical practices without a single mention to DNA. In case a failure in any mechanism necessary to life is found to be genetic in its origin, the genome in context with with this huge set of transcription factors must be taken into account. This is the biochemical line of reasoning that I have learned with Houssay and Leloir. It would be an honor to see it restored in modern terms.”
More on the Mechanism of Metabolic Control
It was important that genomics would play such a large role in medical research for the last 70 years. There is also good reason to rethink the objections of the Nobelists James Watson and Randy Schekman in the past year, whatever discomfort it brings. Molecular biology has become a tautology, and as a result deranged scientific rigor inside biology.
Eatson and Crick
Randy-Schekman Berkeley
According to JES Roselino, “consider that glycolysis is oscillatory thanks to the kinetic behavior of Phosphofructokinase. Further, by its effect upon Pyruvate kinase through Fructose 1,6 diphosphate oscillatory levels, the inhibition of gluconeogenesis is also oscillatory. When the carbon flow through glycolysis is led to a maximal level gluconeogenesis will be almost completely blocked. The reversal of the Pyruvate kinase step in liver requires two enzymes (Pyruvate carboxylase (maintenance of oxaloacetic levels) + phosphoenolpyruvate carboxykinase (E.C. 4.1.1.32)) and energy requiring reactions that most likely could not as an ensemble, have a fast enough response against pyruvate kinase short period of inhibition during high frequency oscillatory periods of glycolytic flow. Only when glycolysis oscillates at low frequency the opposite reaction could enable gluconeogenic carbon flow.”
In case it can be shown in a rather convincing way, the same reasoning could be applied to understand how simple replicative signals inducing Go to G1 transition in cells, could easily overcome more complex signals required for cell differentiation and differentiated function.
Perhaps the problem of overextension of the equivalence of the DNA and what happens to the organism is also related to the initial reliance on a single cell model to relieve the complexity (which isn’t fully the case).
For instance, consider this fragment:
“Until only recently it was assumed that all proteins take on a clearly defined three-dimensional structure – i.e. they fold in order to be able to assume these functions.”
Cold Spring Harbour Symp. Quant. Biol. 1973 p 187-193 J.C Seidel and J Gergely – Investigation of conformational changes in Spin-Labeled Myosin Model for muscle contraction:
Huxley, A. F. 1971 Proc. Roy. Soc (London) (B) 178:1
Huxley, A.F and R. M. Simmons,1971. Nature 233:633
J.C Haselgrove X ray Evidence for a conformational Change in the Actin-containing filaments…Cold Spring Harbour Symp Quant Biol.1972 v 37: p 341-352
Only a very small sample indicating otherwise. Proteins were held as interacting macromolecules, changing their conformation in regulatory response to changes in the microenvironment (See Footnote 2). DNA was the opposite, non-interacting macromolecules to be as stable as a library must be.
The dogma held that the property of proteins could be read in DNA alone. Consequenly, the few examples quoted above, must be ignored and all people must believe that DNA alone, without environmental factors roles, controls protein amino acid sequence (OK), conformation (not true), activity (not true) and function (not true).
It appeared naively to be correct from the dogma to conclude from interpreting your genome: You have a 50% increased risk of developing the following disease (deterministic statement). The correct form must be: You belong to a population that has a 50% increase in the risk of….followed by – what you must do to avoid increase in your personal risk and the care you should take in case you want to have longer healthy life. Thus, genetics and non-genetic diseases were treated as the same and medical foundations were reinforced by magical considerations (dogmas) in a very profitable way for those involved besides the patient.
Footnotes:
There is a link of electricity with ions in biology and the oscillatory behavior of some electrical discharges. In addition, the oscillatory form of electrical discharged may have allowed Planck to relate high energy content with higher frequencies and conversely, low energy content in low frequency oscillatory events. One may think of high density as an indication of great amount of matter inside a volume in space. This helps the understanding of Planck’s idea as a high-density-energy in time for a high frequency phenomenon.
Take into account a protein that may have its conformation restricted by an S-S bridge. This protein also, may move to another more flexible conformation in case it is in HS HS condition when the S-S bridge is broken. Consider also that, it takes some time for a protein to move from one conformation for instance, the restricted conformation (S-S) to other conformations. Also, it takes a few seconds or minutes to return to the S-S conformation (This is the Daniel Koshland´s concept of induced fit and relaxation time used by him in order to explain allosteric behavior of monomeric proteins- Monod, Wyman and Changeux requires tetramer or at least, dimer proteins).
In case you have glycolysis oscillating in a frequency much higher than the relaxation time you could lead to the prevalence of high NADH effect leading to high HS /HS condition and at low glycolytic frequency, you could have predominance of S-S condition affecting protein conformation. In case you have predominance of NAD effect upon protein S-S you would get the opposite results. The enormous effort to display the effect of citrate and over Phosphofructokinase conformation was made by others. Take into account that ATP action as an inhibitor in this case, is a rather unusual one. It is a substrate of the reaction, and together with its action as activator F1,6 P (or its equivalent F2,6 P) is also unusual. However, it explains oscillatory behaviour of glycolysis. (Goldhammer , A.R, and Paradies: PFK structure and function, Curr. Top Cell Reg 1979; 15:109-141).
The results presented in our Hepatology work must be viewed in the following way: In case the hepatic (oxygenated) blood flow is preserved, the bile secretory cells of liver receive well-oxygenated blood flow (the arterial branches bath secretory cells while the branches originated from portal vein irrigate the hepatocytes. During extra hepatic cholestasis the low pressure, portal blood flow is reduced and the hepatocytes do not receive enough oxygen required to produce ATP that gluconeogenesis demands. Hepatic artery do not replace this flow since, its branches only join portal blood fluxes after the previous artery pressure is reduced to a low pressure venous blood – at the point where the formation of hepatic vein is. Otherwise, the flow in the portal vein would be reversed or, from liver to the intestine. It is of no help to take into account possible valves for this reasoning since minimal arterial pressure is well above maximal venous pressure and this difference would keep this valve in permanent close condition. In low portal blood flow condition, the hepatocyte increases pyruvate kinase activity and with increased pyruvate kinase activity Gluconeogenesis is forbidden (See Walsh & Cooper revision quoted in the Hepatology as ref 23). For the hemodynamic considerations, role of artery and veins in hepatic portal system see references 44 and 45 Rappaport and Schneiderman and Rappapaport.
Appendix I.
metabolic pathways
Signals Upstream and Targets Downstream of Lin28 in the Lin28 Pathway
1. Functional Proteomics Adds to Our Understanding
Ben Schuler’s research group from the Institute of Biochemistry of the University of Zurich has now established that an increase in temperature leads to folded proteins collapsing and becoming smaller. Other environmental factors can trigger the same effect. The crowded environments inside cells lead to the proteins shrinking. As these proteins interact with other molecules in the body and bring other proteins together, understanding of these processes is essential “as they play a major role in many processes in our body, for instance in the onset of cancer”, comments study coordinator Ben Schuler.
Measurements using the “molecular ruler”
“The fact that unfolded proteins shrink at higher temperatures is an indication that cell water does indeed play an important role as to the spatial organisation eventually adopted by the molecules”, comments Schuler with regard to the impact of temperature on protein structure. For their studies the biophysicists use what is known as single-molecule spectroscopy. Small colour probes in the protein enable the observation of changes with an accuracy of more than one millionth of a millimetre. With this “molecular yardstick” it is possible to measure how molecular forces impact protein structure.
With computer simulations the researchers have mimicked the behaviour of disordered proteins. They want to use them in future for more accurate predictions of their properties and functions.
Correcting test tube results
That’s why it’s important, according to Schuler, to monitor the proteins not only in the test tube but also in the organism. “This takes into account the fact that it is very crowded on the molecular level in our body as enormous numbers of biomolecules are crammed into a very small space in our cells”, says Schuler. The biochemists have mimicked this “molecular crowding” and observed that in this environment disordered proteins shrink, too.
Given these results many experiments may have to be revisited as the spatial organisation of the molecules in the organism could differ considerably from that in the test tube according to the biochemist from the University of Zurich. “We have, therefore, developed a theoretical analytical method to predict the effects of molecular crowding.” In a next step the researchers plan to apply these findings to measurements taken directly in living cells.
Glucose-6-phosphate dehydrogenase regulation in the hepatopancreas of the anoxia-tolerantmarinemollusc, Littorina littorea
JL Lama , RAV Bell and KB Storey
Glucose-6-phosphate dehydrogenase (G6PDH) gates flux through the pentose phosphate pathway and is key to cellular antioxidant defense due to its role in producing NADPH. Good antioxidant defenses are crucial for anoxia-tolerant organisms that experience wide variations in oxygen availability. The marine mollusc, Littorina littorea, is an intertidal snail that experiences daily bouts of anoxia/hypoxia with the tide cycle and shows multiple metabolic and enzymatic adaptations that support anaerobiosis. This study investigated the kinetic, physical and regulatory properties of G6PDH from hepatopancreas of L. littorea to determine if the enzyme is differentially regulated in response to anoxia, thereby providing altered pentose phosphate pathway functionality under oxygen stress conditions.
Several kinetic properties of G6PDH differed significantly between aerobic and 24 h anoxic conditions; compared with the aerobic state, anoxic G6PDH (assayed at pH 8) showed a 38% decrease in K G6P and enhanced inhibition by urea, whereas in pH 6 assays Km NADP and maximal activity changed significantly.
All these data indicated that the aerobic and anoxic forms of G6PDH were the high and low phosphate forms, respectively, and that phosphorylation state was modulated in response to selected endogenous protein kinases (PKA or PKG) and protein phosphatases (PP1 or PP2C). Anoxia-induced changes in the phosphorylation state of G6PDH may facilitate sustained or increased production of NADPH to enhance antioxidant defense during long term anaerobiosis and/or during the transition back to aerobic conditions when the reintroduction of oxygen causes a rapid increase in oxidative stress.
Structural Basis for Isoform-Selective Inhibition in Nitric Oxide Synthase
TL. Poulos and H Li
In the cardiovascular system, the important signaling molecule nitric oxide synthase (NOS) converts L-arginine into L-citrulline and releases nitric oxide (NO). NO produced by endothelial NOS (eNOS) relaxes smooth muscle which controls vascular tone and blood pressure. Neuronal NOS (nNOS) produces NO in the brain, where it influences a variety of neural functions such as neural transmitter release. NO can also support the immune system, serving as a cytotoxic agent during infections. Even with all of these important functions, NO is a free radical and, when overproduced, it can cause tissue damage. This mechanism can operate in many neurodegenerative diseases, and as a result the development of drugs targeting nNOS is a desirable therapeutic goal.
However, the active sites of all three human isoforms are very similar, and designing inhibitors specific for nNOS is a challenging problem. It is critically important, for example, not to inhibit eNOS owing to its central role in controlling blood pressure. In this Account, we summarize our efforts in collaboration with Rick Silverman at Northwestern University to develop drug candidates that specifically target NOS using crystallography, computational chemistry, and organic synthesis. As a result, we have developed aminopyridine compounds that are 3800-fold more selective for nNOS than eNOS, some of which show excellent neuroprotective effects in animal models. Our group has solved approximately 130 NOS-inhibitor crystal structures which have provided the structural basis for our design efforts. Initial crystal structures of nNOS and eNOS bound to selective dipeptide inhibitors showed that a single amino acid difference (Asp in nNOS and Asn in eNOS) results in much tighter binding to nNOS. The NOS active site is open and rigid, which produces few large structural changes when inhibitors bind. However, we have found that relatively small changes in the active site and inhibitor chirality can account for large differences in isoform-selectivity. For example, we expected that the aminopyridine group on our inhibitors would form a hydrogen bond with a conserved Glu inside the NOS active site. Instead, in one group of inhibitors, the aminopyridine group extends outside of the active site where it interacts with a heme propionate. For this orientation to occur, a conserved Tyr side chain must swing out of the way. This unanticipated observation taught us about the importance of inhibitor chirality and active site dynamics. We also successfully used computational methods to gain insights into the contribution of the state of protonation of the inhibitors to their selectivity. Employing the lessons learned from the aminopyridine inhibitors, the Silverman lab designed and synthesized symmetric double-headed inhibitors with an aminopyridine at each end, taking advantage of their ability to make contacts both inside and outside of the active site. Crystal structures provided yet another unexpected surprise. Two of the double-headed inhibitor molecules bound to each enzyme subunit, and one molecule participated in the generation of a novel Zn site that required some side chains to adopt alternate conformations. Therefore, in addition to achieving our specific goal, the development of nNOS selective compounds, we have learned how subtle differences in and structure can control proteinligand interactions and often in unexpected ways.
Nitric oxide synthase
arginine-NO-citulline cycle
active site of eNOS (PDB_1P6L) and nNOS (PDB_1P6H).
NO – muscle, vasculature, mitochondria
Figure: (A) Structure of one of the early dipeptide lead compounds, 1, that exhibits excellentisoform selectivity. (B, C) show the crystal structures of the dipeptide inhibitor 1 in the active site of eNOS (PDB: 1P6L) and nNOS (PDB: 1P6H). In nNOS, the inhibitor “curls” which enables the inhibitor R-amino group to interact with both Glu592 and Asp597. In eNOS, Asn368 is the homologue to nNOS Asp597.
Accounts in Chem Res 2013; 46(2): 390-98.
Jamming a Protein Signal
Interfering with a single cancer-promoting protein and its receptor can open this resistance mechanism by initiating autophagy of the affected cells, according to researchers at The University of Texas MD Anderson Cancer Center in the journal Cell Reports. According to Dr. Anil Sood and Yunfei Wen, lead and first authors, blocking prolactin, a potent growth factor for ovarian cancer, sets off downstream events that result in cell by autophagy, the process recycles damaged organelles and proteins for new use by the cell through the phagolysozome. This in turn, provides a clinical rationale for blocking prolactin and its receptor to initiate sustained autophagy as an alternative strategy for treating cancers.
Steep reductions in tumor weight
Prolactin (PRL) is a hormone previously implicated in ovarian, endometrial and other cancer development andprogression. When PRL binds to its cell membrane receptor, PRLR, activation of cancer-promoting cell signaling pathways follows. A variant of normal prolactin called G129R blocks the reaction between prolactin and its receptor. Sood and colleagues treated mice that had two different lines of human ovarian cancer, both expressing the prolactin receptor, with G129R. Tumor weights fell by 50 percent for mice with either type of ovarian cancer after 28 days of treatment with G129R, and adding the taxane-based chemotherapy agent paclitaxel cut tumor weight by 90 percent. They surmise that higher doses of G129R may result in even greater therapeutic benefit.
Next the team used the prolactin-mimicking peptide to treat cultures of cancer spheroids which sharply reduced their numbers, and blocked the activation of JAK2 and STAT signaling pathways.
Protein analysis of the treated spheroids showed increased presence of autophagy factors and genomic analysis revealed increased expression of a number of genes involved in autophagy progression and cell death. Then a series of experiments using fluorescence and electron microscopy showed that the cytosol of treated cells had large numbers of cavities caused by autophagy.
The team also connected the G129R-induced autophagy to the activity of PEA-15, a known cancer inhibitor. Analysis of tumor samples from 32 ovarian cancer patients showed that tumors express higher levels of the prolactin receptor and lower levels of phosphorylated PEA-15 than normal ovarian tissue. However, patients with low levels of the prolactin receptor and higher PEA-15 had longer overall survival than those with high PRLR and low PEA-15.
Source: MD Anderson Cancer Center
Chemists’ Work with Small Peptide Chains of Enzymes
Korendovych and his team designed seven simple peptides, each containing seven amino acids. They then allowed the molecules of each peptide to self-assemble, or spontaneously clump together, to form amyloids. (Zinc, a metal with catalytic properties, was introduced to speed up the reaction.) What they found was that four of the seven peptides catalyzed the hydrolysis of molecules known as esters, compounds that react with water to produce water and acids—a feat not uncommon among certain enzymes.
“It was the first time that a peptide this small self-assembled to produce an enzyme-like catalyst,” says Korendovych. “Each enzyme has to be an exact fit for its respective substrate,” he says, referring to the molecule with which an enzyme reacts. “Even after millions of years, nature is still testing all the possible combinations of enzymes to determine which ones can catalyze metabolic reactions. Our results make an argument for the design of self-assembling nanostructured catalysts.”
Source: Syracuse University
Here are three articles emphasizing the value of combinatorial analysis, which can be formed from genomic, clinical, and proteomic data sets.
Comparative analysis of differential network modularity in tissue specific normal and cancer protein interaction networks
F Islam , M Hoque , RS Banik , S Roy , SS Sumi, et al.
As most biological networks show modular properties, the analysis of differential modularity between normal and cancer protein interaction networks can be a good way to understand cancer more significantly. Two aspects of biological network modularity e.g. detection of molecular complexes (potential modules or clusters) and identification of crucial nodes forming the overlapping modules have been considered in this regard.
The computational analysis of previously published protein interaction networks (PINs) has been conducted to identify the molecular complexes and crucial nodes of the networks. Protein molecules involved in ten major cancer signal transduction pathways were used to construct the networks based on expression data of five tissues e.g. bone, breast, colon, kidney and liver in both normal and cancer conditions.
Cancer PINs show higher level of clustering (formation of molecular complexes) than the normal ones. In contrast, lower level modular overlapping is found in cancer PINs than the normal ones. Thus a proposition can be made regarding the formation of some giant nodes in the cancer networks with very high degree and resulting in reduced overlapping among the network modules though the predicted molecular complex numbers are higher in cancer conditions.
Islam et al. Journal of Clinical Bioinformatics 2013, 3:19-32
A new 12-gene diagnostic biomarker signature of melanoma revealed by integrated microarray analysis
Here we present an integrated microarray analysis framework, based on a genome-wide relative significance (GWRS) and genome-wide global significance (GWGS) model. When applied to five microarray datasets on melanoma published between 2000 and 2011, this method revealed a new signature of 200 genes. When these were linked to so-called ‘melanoma driver’ genes involved in MAPK, Ca2+, and WNT signaling pathways we were able to produce a new 12-gene diagnostic biomarker signature for melanoma (i.e., EGFR, FGFR2, FGFR3, IL8, PTPRF, TNC, CXCL13, COL11A1, CHP2, SHC4, PPP2R2C, andWNT4).We have begun to experimentally validate a subset of these genes involved inMAPK signaling at the protein level, including CXCL13, COL11A1, PTPRF and SHC4 and found these to be overexpressed inmetastatic and primarymelanoma cells in vitro and in situ compared to melanocytes cultured from healthy skin epidermis and normal healthy human skin.
catalytic amyloid forming particle
8. PanelomiX: A threshold-based algorithm to create panels of biomarkers
The PanelomiX toolbox combines biomarkers and evaluates the performance of panels to classify patients better than singlemarkers or other classifiers. The ICBTalgorithm proved to be an efficient classifier, the results of which can easily be interpreted.
Here are two current examples of the immense role played by signaling pathways in carcinogenic mechanisms and in treatment targeting, which is also confounded by acquired resistance.
Triple-Negative Breast Cancer
epidermal growth factor receptor (EGFR or ErbB1) and
high activity of the phosphatidylinositol 3-kinase (PI3K)–Akt pathway
are both targeted in triple-negative breast cancer (TNBC).
activation of another EGFR family member [human epidermal growth factor receptor 3 (HER3) (or ErbB3)] may limit the antitumor effects of these drugs.
This study found that TNBC cell lines cultured with the EGFR or HER3 ligand EGF or heregulin, respectively, and treated with either an Akt inhibitor (GDC-0068) or a PI3K inhibitor (GDC-0941) had increased abundance and phosphorylation of HER3.
The phosphorylation of HER3 and EGFR in response to these treatments
was reduced by the addition of a dual EGFR and HER3 inhibitor (MEHD7945A).
MEHD7945A also decreased the phosphorylation (and activation) of EGFR and HER3 and
the phosphorylation of downstream targets that occurred in response to the combination of EGFR ligands and PI3K-Akt pathway inhibitors.
In culture, inhibition of the PI3K-Akt pathway combined with either MEHD7945A or knockdown of HER3
decreased cell proliferation compared with inhibition of the PI3K-Akt pathway alone.
Combining either GDC-0068 or GDC-0941 with MEHD7945A inhibited the growth of xenografts derived from TNBC cell lines or from TNBC patient tumors, and
this combination treatment was also more effective than combining either GDC-0068 or GDC-0941 with cetuximab, an EGFR-targeted antibody.
After therapy with EGFR-targeted antibodies, some patients had residual tumors with increased HER3 abundance and EGFR/HER3 dimerization (an activating interaction).
Thus, we propose that concomitant blockade of EGFR, HER3, and the PI3K-Akt pathway in TNBC should be investigated in the clinical setting.
Reference: Antagonism of EGFR and HER3 Enhances the Response to Inhibitors of the PI3K-Akt Pathway in Triple-Negative Breast Cancer. JJ Tao, P Castel, N Radosevic-Robin, M Elkabets, et al. Sci. Signal., 25 March 2014; 7(318), p. ra29 http://dx.doi.org/10.1126/scisignal.2005125
10. Metastasis in RAS Mutant or Inhibitor-Resistant Melanoma Cells
The protein kinase BRAF is mutated in about 40% of melanomas, and BRAF inhibitors improve progression-free and overall survival in these patients. However, after a relatively short period of disease control, most patients develop resistance because of reactivation of the RAF–ERK (extracellular signal–regulated kinase) pathway, mediated in many cases by mutations in RAS. We found that BRAF inhibition induces invasion and metastasis in RAS mutant melanoma cells through a mechanism mediated by the reactivation of the MEK (mitogen-activated protein kinase kinase)–ERK pathway.
Reference: BRAF Inhibitors Induce Metastasis in RAS Mutant or Inhibitor-Resistant Melanoma Cells by Reactivating MEK and ERK Signaling. B Sanchez-Laorden, A Viros, MR Girotti, M Pedersen, G Saturno, et al., Sci. Signal., 25 March 2014; 7(318), p. ra30 http://dx.doi.org/10.1126/scisignal.2004815
Appendix II.
The world of physics in the twentieth century saw the end of determinism established by Newton. This is characterized by discrete laws that describe natural observations. These are in gravity and in eletricity. In an early phase of investigation, an era of galvanic or voltaic electricity represented a revolutionary break from the historical focus on frictional electricity. Alessandro Voltadiscovered that chemical reactions could be used to create positively charged anodes and negatively charged cathodes. In 1790, Prof. Luigi Alyisio Galvani of Bologna, while conducting experiments on “animal electricity“, noticed the twitching of a frog’s legs in the presence of an electric machine. He observed that a frog’s muscle, suspended on an iron balustrade by a copper hook passing through its dorsal column, underwent lively convulsions without any extraneous cause, the electric machine being at this time absent. Volta communicated a description of his pile to the Royal Society of London and shortly thereafter Nicholson and Cavendish (1780) produced the decomposition of water by means of the electric current, using Volta’s pile as the source of electromotive force.
Siméon Denis Poisson attacked the difficult problem of induced magnetization, and his results provided a first approximation. His innovation required the application of mathematics to physics. His memoirs on the theory of electricity and magnetism created a new branch of mathematical physics. The discovery of electromagnetic induction was made almost simultaneously and independently by Michael Faraday and Joseph Henry. Michael Faraday, the successor of Humphry Davy, began his epoch-making research relating to electric and electromagnetic induction in 1831. In his investigations of the peculiar manner in which iron filings arrange themselves on a cardboard or glass in proximity to the poles of a magnet, Faraday conceived the idea of magnetic “lines of force” extending from pole to pole of the magnet and along which the filings tend to place themselves. On the discovery being made that magnetic effects accompany the passage of an electric current in a wire, it was also assumed that similar magnetic lines of force whirled around the wire. He also posited that iron, nickel, cobalt, manganese, chromium, etc., are paramagnetic (attracted by magnetism), whilst other substances, such as bismuth, phosphorus, antimony, zinc, etc., are repelled by magnetism or are diamagnetic.
Around the mid-19th century, Fleeming Jenkin‘s work on ‘ Electricity and Magnetism ‘ and Clerk Maxwell’s ‘ Treatise on Electricity and Magnetism ‘ were published. About 1850 Kirchhoff published his laws relating to branched or divided circuits. He also showed mathematically that according to the then prevailing electrodynamic theory, electricity would be propagated along a perfectly conducting wire with the velocity of light. Herman Helmholtz investigated the effects of induction on the strength of a current and deduced mathematical equations, which experiment confirmed. In 1853 Sir William Thomson (later Lord Kelvin) predicted as a result of mathematical calculations the oscillatory nature of the electric discharge of a condenser circuit. Joseph Henry, in 1842 discerned the oscillatory nature of the Leyden jardischarge.
In 1864 James Clerk Maxwell announced his electromagnetic theory of light, which was perhaps the greatest single step in the world’s knowledge of electricity. Maxwell had studied and commented on the field of electricity and magnetism as early as 1855/6 when On Faraday’s lines of force was read to the Cambridge Philosophical Society. The paper presented a simplified model of Faraday’s work, and how the two phenomena were related. He reduced all of the current knowledge into a linked set of differential equations with 20 equations in 20 variables. This work was later published as On Physical Lines of Force in1861. In order to determine the force which is acting on any part of the machine we must find its momentum, and then calculate the rate at which this momentum is being changed. This rate of change will give us the force. The method of calculation which it is necessary to employ was first given by Lagrange, and afterwards developed, with some modifications, by Hamilton’s equations. Now Maxwell logically showed how these methods of calculation could be applied to the electro-magnetic field. The energy of a dynamical systemis partly kinetic, partly potential. Maxwell supposes that the magnetic energy of the field is kinetic energy, the electric energypotential. Around 1862, while lecturing at King’s College, Maxwell calculated that the speed of propagation of an electromagnetic field is approximately that of the speed of light. Maxwell’s electromagnetic theory of light obviously involved the existence of electric waves in free space, and his followers set themselves the task of experimentally demonstrating the truth of the theory. By 1871, he presented the Remarks on the mathematical classification of physical quantities.
A Wave-Particle Dilemma at the Century End
In 1896 J.J. Thomson performed experiments indicating that cathode rays really were particles, found an accurate value for their charge-to-mass ratio e/m, and found that e/m was independent of cathode material. He made good estimates of both the charge e and the mass m, finding that cathode ray particles, which he called “corpuscles”, had perhaps one thousandth of the mass of the least massive ion known (hydrogen). He further showed that the negatively charged particles produced by radioactive materials, by heated materials, and by illuminated materials, were universal. In the late 19th century, the Michelson–Morley experiment was performed by Albert Michelson and Edward Morley at what is now Case Western Reserve University. It is generally considered to be the evidence against the theory of a luminiferous aether. The experiment has also been referred to as “the kicking-off point for the theoretical aspects of the Second Scientific Revolution.” Primarily for this work, Albert Michelson was awarded theNobel Prize in 1907.
Wave–particle duality is a theory that proposes that all matter exhibits the properties of not only particles, which have mass, but also waves, which transfer energy. A central concept of quantum mechanics, this duality addresses the inability of classical concepts like “particle” and “wave” to fully describe the behavior of quantum-scale objects. Standard interpretations of quantum mechanics explain this paradox as a fundamental property of the universe, while alternative interpretations explain the duality as an emergent, second-order consequence of various limitations of the observer. This treatment focuses on explaining the behavior from the perspective of the widely used Copenhagen interpretation, in which wave–particle duality serves as one aspect of the concept of complementarity, that one can view phenomena in one way or in another, but not both simultaneously. Through the work of Max Planck, Albert Einstein, Louis de Broglie, Arthur Compton, Niels Bohr, and many others, current scientific theory holds that all particles also have a wave nature (and vice versa).
Beginning in 1670 and progressing over three decades, Isaac Newton argued that the perfectly straight lines of reflection demonstrated light’s particle nature, but Newton’s contemporaries Robert Hooke and Christiaan Huygens—and later Augustin-Jean Fresnel—mathematically refined the wave viewpoint, showing that if light traveled at different speeds in different, refraction could be easily explained. The resulting Huygens–Fresnel principle was supported by Thomas Young‘s discovery of double-slit interference, the beginning of the end for the particle light camp. The final blow against corpuscular theory came when James Clerk Maxwell discovered that he could combine four simple equations, along with a slight modification to describe self-propagating waves of oscillating electric and magnetic fields. When the propagation speed of these electromagnetic waves was calculated, the speed of light fell out. While the 19th century had seen the success of the wave theory at describing light, it had also witnessed the rise of the atomic theory at describing matter.
Matter and Light
In 1789, Antoine Lavoisier secured chemistry by introducing rigor and precision into his laboratory techniques. By discovering diatomic gases, Avogadro completed the basic atomic theory, allowing the correct molecular formulae of most known compounds—as well as the correct weights of atoms—to be deduced and categorized in a consistent manner. The final stroke in classical atomic theory came when Dimitri Mendeleev saw an order in recurring chemical properties, and created a table presenting the elements in unprecedented order and symmetry. Chemistry was now an atomic science.
Black-body radiation, the emission of electromagnetic energy due to an object’s heat, could not be explained from classical arguments alone. The equipartition theorem of classical mechanics, the basis of all classical thermodynamic theories, stated that an object’s energy is partitioned equally among the object’s vibrational modes. This worked well when describing thermal objects, whose vibrational modes were defined as the speeds of their constituent atoms, and the speed distribution derived from egalitarian partitioning of these vibrational modes closely matched experimental results. Speeds much higher than the average speed were suppressed by the fact that kinetic energy is quadratic—doubling the speed requires four times the energy—thus the number of atoms occupying high energy modes (high speeds) quickly drops off. Since light was known to be waves of electromagnetism, physicists hoped to describe this emission via classical laws. This became known as the black body problem. The Rayleigh–Jeans law which, while correctly predicting the intensity of long wavelength emissions, predicted infinite total energy as the intensity diverges to infinity for short wavelengths.
The solution arrived in 1900 when Max Planck hypothesized that the frequency of light emitted by the black body depended on the frequency of the oscillator that emitted it, and the energy of these oscillators increased linearly with frequency (according to his constanth, where E = hν). By demanding that high-frequency light must be emitted by an oscillator of equal frequency, and further requiring that this oscillator occupy higher energy than one of a lesser frequency, Planck avoided any catastrophe; giving an equal partition to high-frequency oscillators produced successively fewer oscillators and less emitted light. And as in the Maxwell–Boltzmann distribution, the low-frequency, low-energy oscillators were suppressed by the onslaught of thermal jiggling from higher energy oscillators, which necessarily increased their energy and frequency. Planck had intentionally created an atomic theory of the black body, but had unintentionally generated an atomic theory of light, where the black body never generates quanta of light at a given frequency with energy less than hν.
In 1905 Albert Einstein took Planck’s black body model in itself and saw a wonderful solution to another outstanding problem of the day: the photoelectric effect, the phenomenon where electrons are emitted from atoms when they absorb energy from light. Only by increasing the frequency of the light, and thus increasing the energy of the photons, can one eject electrons with higher energy. Thus, using Planck’s constant h to determine the energy of the photons based upon their frequency, the energy of ejected electrons should also increase linearly with frequency; the gradient of the line being Planck’s constant. These results were not confirmed until 1915, when Robert Andrews Millikan, produced experimental results in perfect accord with Einstein’s predictions. While the energy of ejected electrons reflected Planck’s constant, the existence of photons was not explicitly proven until the discovery of the photon antibunching effect When Einstein received his Nobel Prizein 1921, it was for the photoelectric effect, the suggestion of quantized light. Einstein’s “light quanta” represented the quintessential example of wave–particle duality. Electromagnetic radiation propagates following linear wave equations, but can only be emitted or absorbed as discrete elements, thus acting as a wave and a particle simultaneously.
Radioactivity Changes the Scientific Landscape
The turn of the century also features radioactivity, which later came to the forefront of the activities of World War II, the Manhattan Project, the discovery of the chain reaction, and later – Hiroshima and Nagasaki.
Marie Curie
Marie Skłodowska-Curie was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. She was the first woman to win a Nobel Prize, the only woman to win in two fields, and the only person to win in multiple sciences. She was also the first woman to become a professor at the University of Paris, and in 1995 became the first woman to be entombed on her own merits in the Panthéon in Paris. She shared the 1903 Nobel Prize in Physics with her husband Pierre Curie and with physicist Henri Becquerel. She won the 1911 Nobel Prize in Chemistry. Her achievements included a theory of radioactivity (a term that she coined, techniques for isolating radioactive isotopes, and the discovery of polonium and radium. She named the first chemical element that she discovered – polonium, which she first isolated in 1898 – after her native country. Under her direction, the world’s first studies were conducted into the treatment of neoplasms using radioactive isotopes. She founded the Curie Institutes in Paris and in Warsaw, which remain major centres of medical research today. During World War I, she established the first military field radiological centres. Curie died in 1934 due to aplastic anemia brought on by exposure to radiation – mainly, it seems, during her World War I service in mobile X-ray units created by her.
Introduction – The Evolution of Cancer Therapy and Cancer Research: How We Got Here?
Author and Curator: Larry H Bernstein, MD, FCAP
The evolution of progress we have achieved in cancer research, diagnosis, and therapeutics has originated from an emergence of scientific disciplines and the focus on cancer has been recent. We can imagine this from a historical perspective with respect to two observations. The first is that the oldest concepts of medicine lie with the anatomic dissection of animals and the repeated recurrence of war, pestilence, and plague throughout the middle ages, and including the renaissance. In the awakening, architecture, arts, music, math, architecture and science that accompanied the invention of printing blossomed, a unique collaboration of individuals working in disparate disciplines occurred, and those who were privileged received an education, which led to exploration, and with it, colonialism. This also led to the need to increasingly, if not without reprisal, questioning long-held church doctrines.
It was in Vienna that Rokitansky developed the discipline of pathology, and his student Semelweis identified an association between then unknown infection and childbirth fever. The extraordinary accomplishments of John Hunter in anatomy and surgery came during the twelve years war, and his student, Edward Jenner, observed the association between cowpox and smallpox resistance. The development of a nursing profession is associated with the work of Florence Nightengale during the Crimean War (at the same time as Leo Tolstoy). These events preceded the work of Pasteur, Metchnikoff, and Koch in developing a germ theory, although Semelweis had committed suicide by infecting himself with syphilis. The first decade of the Nobel Prize was dominated by discoveries in infectious disease and public health (Ronald Ross, Walter Reed) and we know that the Civil War in America saw an epidemic of Yellow Fever, and the Armed Services Medical Museum was endowed with a large repository of osteomyelitis specimens. We also recall that the Russian physician and playwriter, Anton Checkov, wrote about the conditions in prison camps.
But the pharmacopeia was about to open with the discoveries of insulin, antibiotics, vitamins, thyroid action (Mayo brothers pioneered thyroid surgery in the thyroid iodine-deficient midwest), and pitutitary and sex hormones (isolatation, crystal structure, and synthesis years later), and Karl Landsteiner’s discovery of red cell antigenic groups (but he also pioneered in discoveries in meningitis and poliomyelitis, and conceived of the term hapten) with the introduction of transfusion therapy that would lead to transplantation medicine. The next phase would be heralded by the discovery of cancer, which was highlighted by the identification of leukemia by Rudolph Virchow, who cautioned about the limitations of microscopy. This period is highlighted by the classic work – “Microbe Hunters”.
John Hunter
Walter Reed
Robert Koch
goldberger 1916 Pellagra
Louis Pasteur
A multidisciplinary approach has led us to a unique multidisciplinary or systems view of cancer, with different fields of study offering their unique expertise, contributions, and viewpoints on the etiology of cancer. Diverse fields in immunology, biology, biochemistry, toxicology, molecular biology, virology, mathematics, social activism and policy, and engineering have made such important contributions to our understanding of cancer, that without cooperation among these diverse fields our knowledge of cancer would never had evolved as it has. In a series of posts “Heroes in Medical Research:” the work of researchers are highlighted as examples of how disparate scientific disciplines converged to produce seminal discoveries which propelled the cancer field, although, at the time, they seemed like serendipitous findings. In the post Heroes in Medical Research: Barnett Rosenberg and the Discovery of Cisplatin (Translating Basic Research to the Clinic) discusses the seminal yet serendipitous discoveries by bacteriologist Dr. Barnett Rosenberg, which eventually led to the development of cisplatin, a staple of many chemotherapeutic regimens. Molecular biologist Dr. Robert Ting, working with soon-to-be Nobel Laureate virologist Dr. James Gallo on AIDS research and the associated Karposi’s sarcoma identified one of the first retroviral oncogenes, revolutionizing previous held misconceptions of the origins of cancer (described in Heroes in Medical Research: Dr. Robert Ting, Ph.D. and Retrovirus in AIDS and Cancer). Located here will be a MONTAGE of PHOTOS of PEOPLE who made seminal discoveries and contributions in every field to cancer Each of these paths of discovery in cancer research have led to the unique strategies of cancer therapeutics and detection for the purpose of reducing the burden of human cancer. However, we must recall that this work has come at great cost, while it is indeed cause for celebration. The current failure rate of clinical trials at over 70 percent, has been a cause for disappointment, and has led to serious reconsideration of how we can proceed with greater success. The result of the evolution of the cancer field is evident in the many parts and chapters of this ebook. Volume 4 contains chapters that are in a predetermined order:
The concepts of neoplasm, malignancy, carcinogenesis, and metastatic potential, which encompass:
(a) How cancer cells bathed in an oxygen rich environment rely on anaerobic glycolysis for energy, and the secondary consequences of cachexia and sarcopenia associated with progression
invasion
ARTS protein and cancer
Glycolysis
Krebs cycle
Metabolic control analysis of respiration in human cancer tissue
akip1-expression-modulates-mitochondrial-function
(b) How advances in genetic analysis, molecular and cellular biology, metabolomics have expanded our basic knowledge of the mechanisms which are involved in cellular transformation to the cancerous state.
nucleotides
Methylation of adenine
ampk-and-ampk-related-kinase-ark-family-
ubiquitylation
(c) How molecular techniques continue to advance our understanding of how genetics, epigenetics, and alterations in cellular metabolism contribute to cancer and afford new pathways for therapeutic intervention.
genomic effects
LKB1AMPK pathway
mutation-frequencies-across-12-cancer-types
AMPK-activating drugs metformin or phenformin might provide protection against cancer
2. The distinct features of cancers of specific tissue sites of origin
3. The diagnosis of cancer by
(a) Clinical presentation
(b) Age of onset and stage of life
(c) Biomarker features
hairy cell leukemia
lymphoma leukemia
(d) Radiological and ultrasound imaging
Treatments
Prognostic differences within and between cancer types
We have introduced the emergence of a disease of great complexity that has been clouded in more questions than answers until the emergence of molecular biology in the mid 20th century, and then had to await further discoveries going into the 21st century. What gave the research impetus was the revelation of
1 the mechanism of transcription of the DNA into amino acid sequences
Proteins in Disease
2 the identification of stresses imposed on cellular function
NO beneficial effects
3 the elucidation of the substructure of the cell – cell membrane, mitochondria, ribosomes, lysosomes – and their functions, respectively
AKIP1 Expression Modulates Mitochondrial Function
4 the elucidation of oligonucleotide sequences
nucleotides
dna-replication-unwinding
dna-replication-ligation
dna-replication-primer-removal
dna-replication-leading-strand
dna-replication-lagging-strand
dna-replication-primer-synthesis
dna-replication-termination
5 the further elucidation of functionally relevant noncoding lncDNA
6 the technology to synthesis mRNA and siRNA sequences
Figure. RNAi and gene silencing
7 the repeated discovery of isoforms of critical enzymes and their pleiotropic properties
8. the regulatory pathways involved in signaling
Figure. Signaling Pathways Map
This is a brief outline of the modern progression of advances in our understanding of cancer. Let us go back to the beginning and check out a sequence of Nobel Prizes awarded and related discoveries that have a historical relationship to what we know. The first discovery was the finding by Louis Pasteur that fungi that grew in an oxygen poor environment did not put down filaments. They did not utilize oxygen and they produced used energy by fermentation. This was the basis for Otto Warburg sixty years later to make the comparison to cancer cells that grew in the presence of oxygen, but relied on anaerobic glycolysis. He used a manometer to measure respiration in tissue one cell layer thick to measure CO2 production in an adiabatic system.
Lavoisier Antoine-Laurent and Laplace Pierre-Simon (1783) Memoir on heat. Mémoirs de l’Académie des sciences. Translated by Guerlac H, Neale Watson Academic Publications, New York, 1982.
The Warburg apparatus is a manometric respirometer which was used for decades in biochemistry for measuring oxygen consumption of tissue homogenates or tissue slices.
The aqueous phase is vigorously shaken to equilibrate with a gas phase, from which oxygen is consumed while the evolved carbon dioxide is trapped, such that the pressure in the constant-volume gas phase drops proportional to oxygen consumption. The Warburg apparatus was introduced to study cell respiration, i.e. the uptake of molecular oxygen and the production of carbon dioxide by cells or tissues. Its applications were extended to the study of fermentation, when gas exchange takes place in the absence of oxygen. Thus the Warburg apparatus became established as an instrument for both aerobic and anaerobic biochemical studies [2, 3].
The respiration chamber was a detachable glass flask (F) equipped with one or more sidearms (S) for additions of chemicals and an open connection to a manometer (M; pressure gauge). A constant temperature was provided by immersion of the Warburg chamber in a constant temperature water bath. At thermal mass transfer equilibrium, an initial reading is obtained on the manometer, and the volume of gas produced or absorbed is determined at specific time intervals. A limited number of ‘titrations’ can be performed by adding the liquid contained in a side arm into the main reaction chamber. A Warburg apparatus may be equipped with more than 10 respiration chambers shaking in a common water bath. Since temperature has to be controlled very precisely in a manometric approach, the early studies on mammalian tissue respiration were generally carried out at a physiological temperature of 37 °C.
The Warburg apparatus has been replaced by polarographic instruments introduced by Britton Chance in the 1950s. Since Chance and Williams (1955) measured respiration of isolated mitochondria simultaneously with the spectrophotometric determination of cytochrome redox states, a water chacket could not be used, and measurements were carried out at room temperature (or 25 °C). Thus most later studies on isolated mitochondria were shifted to the artifical temperature of 25 °C.
Today, the importance of investigating mitochondrial performance at in vivo temperatures is recognized again in mitochondrial physiology. Incubation times of 1 hour were typical in experiments with the Warburg apparatus, but were reduced to a few or up to 20 min, following Chance and Williams, due to rapid oxygen depletion in closed, aqueous phase oxygraphs with high sample concentrations. Today, incubation times of 1 hour are typical again in high-resolution respirometry, with low sample concentrations and the option of reoxygenations.
Oesper P (1964) The history of the Warburg apparatus: Some reminiscences on its use. J Chem Educ 41: 294.
Koppenol WH, Bounds PL, Dang CV (2011) Otto Warburg’s contributions to current concepts of cancer metabolism. Nature Reviews Cancer 11: 325-337.
Gnaiger E, Kemp RB (1990) Anaerobic metabolism in aerobic mammalian cells: information from the ratio of calorimetric heat flux and respirometric oxygen flux. Biochim Biophys Acta 1016: 328-332. – “At high fructose concentrations, respiration is inhibited while glycolytic end products accumulate, a phenomenon known as the Crabtree effect. It is commonly believed that this effect is restricted to microbial and tumour cells with uniquely high glycolytic capacities (Sussman et al, 1980). However, inhibition of respiration and increase of lactate production are observed under aerobic conditions in beating rat heart cell cultures (Frelin et al, 1974) and in isolated rat lung cells (Ayuso-Parrilla et al, 1978). Thus, the same general mechanisms responsible for the integration of respiration and glycolysis in tumour cells (Sussman et al, 1980) appear to be operating to some extent in several isolated mammalian cells.”
Mitochondria are sometimes described as “cellular power plants” because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy.[2] In addition to supplying cellular energy, mitochondria are involved in other tasks such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth.[3] The organelle is composed of compartments that carry out specialized functions. These compartments or regions include the outer membrane, the intermembrane space, the inner membrane, and the cristae and matrix. Mitochondrial proteins vary depending on the tissue and the species. In humans, 615 distinct types of proteins have been identified from cardiac mitochondria,[9Leonor Michaelis discovered that Janus green can be used as a supravital stain for mitochondria in 1900. Benjamin F. Kingsbury, in 1912, first related them with cell respiration, but almost exclusively based on morphological observations.[13] In 1913 particles from extracts of guinea-pig liver were linked to respiration by Otto Heinrich Warburg, which he called “grana”. Warburg and Heinrich Otto Wieland, who had also postulated a similar particle mechanism, disagreed on the chemical nature of the respiration. It was not until 1925 when David Keilin discovered cytochromes that the respiratory chain was described.[13]
The Clark Oxygen Sensor
Dr. Leland Clark – inventor of the “Clark Oxygen Sensor” (1954); the Clark type polarographic oxygen sensor remains the gold standard for measuring dissolved oxygen in biomedical, environmental and industrial applications . ‘The convenience and simplicity of the polarographic ‘oxygen electrode’ technique for measuring rapid changes in the rate of oxygen utilization by cellular and subcellular systems is now leading to its more general application in many laboratories. The types and design of oxygen electrodes vary, depending on the investigator’s ingenuity and specific requirements of the system under investigation.’Estabrook R (1967) Mitochondrial respiratory control and the polarographic measurement of ADP:O ratios. Methods Enzymol. 10: 41-47. “one approach that is underutilized in whole-cell bioenergetics, and that is accessible as long as cells can be obtained in suspension, is the oxygen electrode, which can obtain more precise information on the bioenergetic status of the in situ mitochondria than more ‘high-tech’ approaches such as fluorescent monitoring ofΔψm.” Nicholls DG, Ferguson S (2002) Bioenergetics 3. Academic Press, London.
Great Figures in Cancer
Dr. Elizabeth Blackburn,
j_michael_bishop onogene
Harold Varmus
Potts and Habener (PTH mRNA, Harvard MIT) JCI
JCI Fuller Albright and hPTH AA sequence
Dr. E. Donnall Thomas Bone Marrow Transplants
Dr Haraldzur Hausen EBV HPV
Dr. Craig Mello
Lee Hartwell – Hutchinson Cancer Res Center
Judah Folkman, MD
Gertrude B. Elien (1918-1999)
The Nobel Prize in Physiology or Medicine 1922
Archibald V. Hill, Otto Meyerhof
AV Hill –
“the production of heat in the muscle” Hill started his research work in 1909. It was due to J.N. Langley, Head of the Department of Physiology at that time that Hill took up the study on the nature of muscular contraction. Langley drew his attention to the important (later to become classic) work carried out by Fletcher and Hopkins on the problem of lactic acid in muscle, particularly in relation to the effect of oxygen upon its removal in recovery. In 1919 he took up again his study of the physiology of muscle, and came into close contact with Meyerhof of Kiel who, approaching the problem differently, arrived at results closely analogous to his study. In 1919 Hill’s friend W. Hartree, mathematician and engineer, joined in the myothermic investigations – a cooperation which had rewarding results.
Otto Meyerhof –
otto-fritz-meyerhof
lactic acid production in muscle contraction Under the influence of Otto Warburg, then at Heidelberg, Meyerhof became more and more interested in cell physiology. In 1923 he was offered a Professorship of Biochemistry in the United States, but Germany was unwilling to lose him. In 1929 he was he was placed in charge of the newly founded Kaiser Wilhelm Institute for Medical Research at Heidelberg. From 1938 to 1940 he was Director of Research at the Institut de Biologie physico-chimique at Paris, but in 1940 he moved to the United States, where the post of Research Professor of Physiological Chemistry had been created for him by the University of Pennsylvania and the Rockefeller Foundation. Meyerhof’s own account states that he was occupied chiefly with oxidation mechanisms in cells and with extending methods of gas analysis through the calorimetric measurement of heat production, and especially the respiratory processes of nitrifying bacteria. The physico-chemical analogy between oxygen respiration and alcoholic fermentation caused him to study both these processes in the same subject, namely, yeast extract. By this work he discovered a co-enzyme of respiration, which could be found in all the cells and tissues up till then investigated. At the same time he also found a co-enzyme of alcoholic fermentation. He also discovered the capacity of the SH-group to transfer oxygen; after Hopkins had isolated from cells the SH bodies concerned, Meyerhof showed that the unsaturated fatty acids in the cell are oxidized with the help of the sulfhydryl group. After studying closer the respiration of muscle, Meyerhof investigated the energy changes in muscle. Considerable progress had been achieved by the English scientists Fletcher and Hopkins by their recognition of the fact that lactic acid formation in the muscle is closely connected with the contraction process. These investigations were the first to throw light upon the highly paradoxical fact, already established by the physiologist Hermann, that the muscle can perform a considerable part of its external function in the complete absence of oxygen.
But it was indisputable that in the last resort the energy for muscle activity comes from oxidation, so the connection between activity and combustion must be an indirect one, and observed that in the absence of oxygen in the muscle, lactic acid appears, slowly in the relaxed state and rapidly in the active state, disappearing in the presence of oxygen. Obviously, then, oxygen is involved when muscle is in the relaxed state. http://upload.wikimedia.org/wikipedia/commons/e/e1/Glycolysis.jpg
The Nobel Prize committee had been receiving nominations intermittently for the previous 14 years (for Eijkman, Funk, Goldberger, Grijns, Hopkins and Suzuki but, strangely, not for McCollum in this period). Tthe Committee for the 1929 awards apparently agreed that it was high time to honor the discoverer(s) of vitamins; but who were they? There was a clear case for Grijns, but he had not been re-nominated for that particular year, and it could be said that he was just taking the relatively obvious next steps along the new trail that had been laid down by Eijkman, who was also now an old man in poor health, but there was no doubt that he had taken the first steps in the use of an animal model to investigate the nutritional basis of a clinical disorder affecting millions. Goldberger had been another important contributor, but his recent death put him out of consideration. The clearest evidence for lack of an unknown “something” in a mammalian diet was presented by Gowland Hopkins in 1912. This Cambridge biochemist was already well known for having isolated the amino acid tryptophan from a protein and demonstrated its essential nature. He fed young rats on an experimental diet, half of them receiving a daily milk supplement, and only those receiving milk grew well, Hopkins suggested that this was analogous to human diseases related to diet, as he had suggested already in a lecture published in 1906. Hopkins, the leader of the “dynamic biochemistry” school in Britain and an influential advocate for the importance of vitamins, was awarded the prize jointly with Eijkman. A door was opened. Recognition of work on the fat-soluble vitamins begun by McCollum. The next award related to vitamins was given in 1934 to George Whipple, George Minot and William Murphy “for their discoveries concerning liver therapy in cases of [then incurable pernicious] anemia,” The essential liver factor (cobalamin, or vitamin B12) was isolated in 1948, and Vitamin B12 was absent from plant foods. But William Castle in 1928 had demonstrated that the stomachs of pernicious anemia patients were abnormal in failing to secrete an “intrinsic factor”.
Szent-Györgyi was a Hungarian biochemist who had worked with Otto Warburg and had a special interest in oxidation-reduction mechanisms. He was invited to Cambridge in England in 1927 after detecting an antioxidant compound in the adrenal cortex, and there, he isolated a compound that he named hexuronic acid. Charles Glen King of the University of Pittsburgh reported success In isolating the anti-scorbutic factor in 1932, and added that his crystals had all the properties reported by Szent-Györgyi for hexuronic acid. But his work on oxidation reactions was also important. Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP) from food. It is formed by the oxidation of succinate by the enzyme succinate dehydrogenase. Fumarate is then converted by the enzyme fumarase to malate. An enzyme adds water to the fumarate molecule to form malate. The malate is created by adding one hydrogen atom to a carbon atom and then adding a hydroxyl group to a carbon next to a terminal carbonyl group.
In the same year, Norman Haworth from the University of Birmingham in England received a Nobel prize from the Chemistry Committee for having advanced carbohydrate chemistry and, specifically, for having worked out the structure of Szent-Györgyi’s crystals, and then been able to synthesize the vitamin. This was a considerable achievement. The Nobel Prize in Chemistry was shared with the Swiss organic chemist Paul Karrer, cited for his work on the structures of riboflavin and vitamins A and E as well as other biologically interesting compounds. This was followed in 1938 by a further Chemistry award to the German biochemist Richard Kuhn, who had also worked on carotenoids and B-vitamins, including riboflavin and pyridoxine. But Karrer was not permitted to leave Germany at that time by the Nazi regime. However, the American work with radioisotopes at Lawrence Livermore Laboratory, UC Berkeley, was already ushering in a new era of biochemistry that would enrich our studies of metabolic pathways. The importance of work involving vitamins was acknowledged in at least ten awards in the 20th century.
1. Carpenter, K.J., Beriberi, White Rice and Vitamin B, University of California Press, Berkeley (2000).
2. Weatherall, M.W. and Kamminga, H., The making of a biochemist: the construction of Frederick Gowland Hopkins’ reputation. Medical History vol.40, pp. 415-436 (1996).
3. Becker, S.L., Will milk make them grow? An episode in the discovery of the vitamins. In Chemistry and Modern Society (J. Parascandela, editor) pp. 61-83, American Chemical Society,
Washington, D.C. (1983).
4. Carpenter, K.J., The History of Scurvy and Vitamin C, Cambridge University Press, New York (1986).
Transport and metabolism of exogenous fumarate and 3-phosphoglycerate in vascular smooth muscle.
The keto (linear) form of exogenous fructose 1,6-bisphosphate, a highly charged glycolytic intermediate, may utilize a dicarboxylate transporter to cross the cell membrane, support glycolysis, and produce ATP anaerobically. We tested the hypothesis that fumarate, a dicarboxylate, and 3-phosphoglycerate (3-PG), an intermediate structurally similar to a dicarboxylate, can support contraction in vascular smooth muscle during hypoxia. 3-PG improved maintenance of force (p < 0.05) during the 30-80 min period of hypoxia. Fumarate decreased peak isometric force development by 9.5% (p = 0.008) but modestly improved maintenance of force (p < 0.05) throughout the first 80 min of hypoxia. 13C-NMR on tissue extracts and superfusates revealed 1,2,3,4-(13)C-fumarate (5 mM) metabolism to 1,2,3,4-(13)C-malate under oxygenated and hypoxic conditions suggesting uptake and metabolism of fumarate. In conclusion, exogenous fumarate and 3-PG readily enter vascular smooth muscle cells, presumably by a dicarboxylate transporter, and support energetically important pathways.
Comparison of endogenous and exogenous sources of ATP in fueling Ca2+ uptake in smooth muscle plasma membrane vesicles.
A smooth muscle plasma membrane vesicular fraction (PMV) purified for the (Ca2+/Mg2+)-ATPase has endogenous glycolytic enzyme activity. In the presence of glycolytic substrate (fructose 1,6-diphosphate) and cofactors, PMV produced ATP and lactate and supported calcium uptake. The endogenous glycolytic cascade supports calcium uptake independent of bath [ATP]. A 10-fold dilution of PMV, with the resultant 10-fold dilution of glycolytically produced bath [ATP] did not change glycolytically fueled calcium uptake (nanomoles per milligram protein). Furthermore, the calcium uptake fueled by the endogenous glycolytic cascade persisted in the presence of a hexokinase-based ATP trap which eliminated calcium uptake fueled by exogenously added ATP. Thus, it appears that the endogenous glycolytic cascade fuels calcium uptake in PMV via a membrane-associated pool of ATP and not via an exchange of ATP with the bulk solution. To determine whether ATP produced endogenously was utilized preferentially by the calcium pump, the ATP production rates of the endogenous creatine kinase and pyruvate kinase were matched to that of glycolysis and the calcium uptake fueled by the endogenous sources was compared with that fueled by exogenous ATP added at the same rate. The rate of calcium uptake fueled by endogenous sources of ATP was approximately twice that supported by exogenously added ATP, indicating that the calcium pump preferentially utilizes ATP produced by membrane-bound enzymes.
Evidence for succinate production by reduction of fumarate during hypoxia in isolated adult rat heart cells.
Archives of Biochemistry and Biophysics (Impact Factor: 3.37). 01/1988; 259(2):527-35. http://dx.doi.org:/10.1016/0003-9861(87)90519-4 It has been demonstrated that perfusion of myocardium with glutamic acid or tricarboxylic acid cycle intermediates during hypoxia or ischemia, improves cardiac function, increases ATP levels, and stimulates succinate production. In this study isolated adult rat heart cells were used to investigate the mechanism of anaerobic succinate formation and examine beneficial effects attributed to ATP generated by this pathway. Myocytes incubated for 60 min under hypoxic conditions showed a slight loss of ATP from an initial value of 21 +/- 1 nmol/mg protein, a decline of CP from 42 to 17 nmol/mg protein and a fourfold increase in lactic acid production to 1.8 +/- 0.2 mumol/mg protein/h. These metabolite contents were not altered by the addition of malate and 2-oxoglutarate to the incubation medium nor were differences in cell viability observed; however, succinate release was substantially accelerated to 241 +/- 53 nmol/mg protein. Incubation of cells with [U-14C]malate or [2-U-14C]oxoglutarate indicates that succinate is formed directly from malate but not from 2-oxoglutarate. Moreover, anaerobic succinate formation was rotenone sensitive.
We conclude that malate reduction to succinate occurs via the reverse action of succinate dehydrogenase in a coupled reaction where NADH is oxidized (and FAD reduced) and ADP is phosphorylated.Furthermore, by transaminating with aspartate to produce oxaloacetate, 2-oxoglutarate stimulates cytosolic malic dehydrogenase activity, whereby malate is formed and NADH is oxidized.
In the form of malate, reducing equivalents and substrate are transported into the mitochondria where they are utilized for succinate synthesis.
1953 Hans Adolf Krebs –
” discovery of the citric acid cycle” and In the course of the 1920’s and 1930’s great progress was made in the study of the intermediary reactions by which sugar is anaerobically fermented to lactic acid or to ethanol and carbon dioxide. The success was mainly due to the joint efforts of the schools of Meyerhof, Embden, Parnas, von Euler, Warburg and the Coris, who built on the pioneer work of Harden and of Neuberg. This work brought to light the main intermediary steps of anaerobic fermentations.
In contrast, very little was known in the earlier 1930’s about the intermediary stages through which sugar is oxidized in living cells. When, in 1930, I left the laboratory of Otto Warburg (under whose guidance I had worked since 1926 and from whom I have learnt more than from any other single teacher), I was confronted with the question of selecting a major field of study and I felt greatly attracted by the problem of the intermediary pathway of oxidations.
These reactions represent the main energy source in higher organisms, and in view of the importance of energy production to living organisms (whose activities all depend on a continuous supply of energy) the problem seemed well worthwhile studying. http://www.johnkyrk.com/krebs.html
Interactive Krebs cycle
There are different points where metabolites enter the Krebs’ cycle. Most of the products of protein, carbohydrates and fat metabolism are reduced to the molecule acetyl coenzyme A that enters the Krebs’ cycle. Glucose, the primary fuel in the body, is first metabolized into pyruvic acid and then into acetyl coenzyme A. The breakdown of the glucose molecule forms two molecules of ATP for energy in the Embden Meyerhof pathway process of glycolysis.
On the other hand, amino acids and some chained fatty acids can be metabolized into Krebs intermediates and enter the cycle at several points. When oxygen is unavailable or the Krebs’ cycle is inhibited, the body shifts its energy production from the Krebs’ cycle to the Embden Meyerhof pathway of glycolysis, a very inefficient way of making energy.
Fritz Albert Lipmann –
“discovery of co-enzyme A and its importance for intermediary metabolism”.
In my development, the recognition of facts and the rationalization of these facts into a unified picture, have interplayed continuously. After my apprenticeship with Otto Meyerhof, a first interest on my own became the phenomenon we call the Pasteur effect, this peculiar depression of the wasteful fermentation in the respiring cell. By looking for a chemical explanation of this economy measure on the cellular level, I was prompted into a study of the mechanism of pyruvic acid oxidation, since it is at the pyruvic stage where respiration branches off from fermentation.
For this study I chose as a promising system a relatively simple looking pyruvic acid oxidation enzyme in a certain strain of Lactobacillus delbrueckii1. In 1939, experiments using minced muscle cells demonstrated that one oxygen atom can form two adenosine triphosphate molecules, and, in 1941, the concept of phosphate bonds being a form of energy in cellular metabolism was developed by Fritz Albert Lipmann.
In the following years, the mechanism behind cellular respiration was further elaborated, although its link to the mitochondria was not known.[13]The introduction of tissue fractionation by Albert Claude allowed mitochondria to be isolated from other cell fractions and biochemical analysis to be conducted on them alone. In 1946, he concluded that cytochrome oxidase and other enzymes responsible for the respiratory chain were isolated to the mitchondria. Over time, the fractionation method was tweaked, improving the quality of the mitochondria isolated, and other elements of cell respiration were determined to occur in the mitochondria.[13]
The most important event during this whole period, I now feel, was the accidental observation that in the L. delbrueckii system, pyruvic acid oxidation was completely dependent on the presence of inorganic phosphate. This observation was made in the course of attempts to replace oxygen by methylene blue. To measure the methylene blue reduction manometrically, I had to switch to a bicarbonate buffer instead of the otherwise routinely used phosphate. In bicarbonate, pyruvate oxidation was very slow, but the addition of a little phosphate caused a remarkable increase in rate. The phosphate effect was removed by washing with a phosphate free acetate buffer. Then it appeared that the reaction was really fully dependent on phosphate.
A coupling of this pyruvate oxidation with adenylic acid phosphorylation was attempted. Addition of adenylic acid to the pyruvic oxidation system brought out a net disappearance of inorganic phosphate, accounted for as adenosine triphosphate. The acetic acid subunit of acetyl CoA is combined with oxaloacetate to form a molecule of citrate. Acetyl coenzyme A acts only as a transporter of acetic acid from one enzyme to another. After Step 1, the coenzyme is released by hydrolysis to combine with another acetic acid molecule and begin the Krebs’ Cycle again.
Hugo Theorell –
“the nature and effects of oxidation enzymes”
From 1933 until 1935 Theorell held a Rockefeller Fellowship and worked with Otto Warburg at Berlin-Dahlem, and here he became interested in oxidation enzymes. At Berlin-Dahlem he produced, for the first time, the oxidation enzyme called «the yellow ferment» and he succeeded in splitting it reversibly into a coenzyme part, which was found to be flavin mononucleotide, and a colourless protein part. On return to Sweden, he was appointed Head of the newly established Biochemical Department of the Nobel Medical Institute, which was opened in 1937.
Succinate is oxidized by a molecule of FAD (Flavin Adenine Dinucleotide). The FAD removes two hydrogen atoms from the succinate and forms a double bond between the two carbon atoms to create fumarate.
They followed the path that became clear from intense collaborative work in California by George Beadle, by Avery and McCarthy, Max Delbruck, TH Morgan, Max Delbruck and by Chargaff that indicated that genetics would be important.
1965
François Jacob, André Lwoff and Jacques Monod –
” genetic control of enzyme and virus synthesis”.
In 1958 the remarkable analogy revealed by genetic analysis of lysogeny and that of the induced biosynthesis of ß-galactosidase led François Jacob, with Jacques Monod, to study the mechanisms responsible for the transfer of genetic information as well as the regulatory pathways which, in the bacterial cell, adjust the activity and synthesis of macromolecules. Following this analysis, Jacob and Monod proposed a series of new concepts, those of messenger RNA, regulator genes, operons and allosteric proteins.
Francois Jacob
Having determined the constants of growth in the presence of different carbohydrates, it occurred to me that it would be interesting to determine the same constants in paired mixtures of carbohydrates. From the first experiment on, I noticed that, whereas the growth was kinetically normal in the presence of certain mixtures (that is, it exhibited a single exponential phase), two complete growth cycles could be observed in other carbohydrate mixtures, these cycles consisting of two exponential phases separated by a-complete cessation of growth.
Lwoff, after considering this strange result for a moment, said to me, “That could have something to do with enzyme adaptation.”
“Enzyme adaptation? Never heard of it!” I said.
Lwoff’s only reply was to give me a copy of the then recent work of Marjorie Stephenson, in which a chapter summarized with great insight the still few studies concerning this phenomenon, which had been discovered by Duclaux at the end of the last century. Studied by Dienert and by Went as early as 1901 and then by Euler and Josephson, it was more or less rediscovered by Karström, who should be credited with giving it a name and attracting attention to its existence.
Lwoff’s intuition was correct. The phenomenon of “diauxy” that I had discovered was indeed closely related to enzyme adaptation, as my experiments, included in the second part of my doctoral dissertation, soon convinced me. It was actually a case of the “glucose effect” discovered by Dienert as early as 1900. That agents that uncouple oxidative phosphorylation, such as 2,4-dinitrophenol, completely inhibit adaptation to lactose or other carbohydrates suggested that “adaptation” implied an expenditure of chemical potential and therefore probably involved the true synthesis of an enzyme.
With Alice Audureau, I sought to discover the still quite obscure relations between this phenomenon and the one Massini, Lewis, and others had discovered: the appearance and selection of “spontaneous” mutants. We showed that an apparently spontaneous mutation was allowing these originally “lactose-negative” bacteria to become “lactose-positive”. However, we proved that the original strain (Lac-) and the mutant strain (Lac+) did not differ from each other by the presence of a specific enzyme system, but rather by the ability to produce this system in the presence of lactose. This mutation involved the selective control of an enzyme by a gene, and the conditions necessary for its expression seemed directly linked to the chemical activity of the system.
1974
Albert Claude, Christian de Duve and George E. Palade –
” the structural and functional organization of the cell”.
I returned to Louvain in March 1947 after a period of working with Theorell in Sweden, the Cori’s, and E Southerland in St. Louis, fortunate in the choice of my mentors, all sticklers for technical excellence and intellectual rigor, those prerequisites of good scientific work. Insulin, together with glucagon which I had helped rediscover, was still my main focus of interest, and our first investigations were accordingly directed on certain enzymatic aspects of carbohydrate metabolism in liver, which were expected to throw light on the broader problem of insulin action. But I became distracted by an accidental finding related to acid phosphatase, drawing most of my collaborators along with me. The studies led to the discovery of the lysosome, and later of the peroxisome.
In 1962, I was appointed a professor at the Rockefeller Institute in New York, now the Rockefeller University, the institution where Albert Claude had made his pioneering studies between 1929 and 1949, and where George Palade had been working since 1946. In New York, I was able to develop a second flourishing group, which follows the same general lines of research as the Belgian group, but with a program of its own.
1968
Robert W. Holley, Har Gobind Khorana and Marshall W. Nirenberg –
“interpretation of the genetic code and its function in protein synthesis”.
1969
Max Delbrück, Alfred D. Hershey and Salvador E. Luria –
” the replication mechanism and the genetic structure of viruses”.
1975 David Baltimore, Renato Dulbecco and Howard Martin Temin –
” the interaction between tumor viruses and the genetic material of the cell”.
1976
Baruch S. Blumberg and D. Carleton Gajdusek –
” new mechanisms for the origin and dissemination of infectious diseases” The editors of the Nobelprize.org website of the Nobel Foundation have asked me to provide a supplement to the autobiography that I wrote in 1976 and to recount the events that happened after the award. Much of what I will have to say relates to the scientific developments since the last essay. These are described in greater detail in a scientific memoir first published in 2002 (Blumberg, B. S., Hepatitis B. The Hunt for a Killer Virus, Princeton University Press, 2002, 2004).
1980
Baruj Benacerraf, Jean Dausset and George D. Snell
” genetically determined structures on the cell surface that regulate immunological reactions”.
1992
Edmond H. Fischer and Edwin G. Krebs
“for their discoveries concerning reversible protein phosphorylation as a biological regulatory mechanism”
1994
Alfred G. Gilman and Martin Rodbell –
“G-proteins and the role of these proteins in signal transduction in cells”
2011
Bruce A. Beutler and Jules A. Hoffmann –
” the activation of innate immunity“and the other half to Ralph M. Steinman – “the dendritic cell and its role in adaptive immunity”.
Renato L. Baserga, M.D.
Kimmel Cancer Center and Keck School of Medicine
Dr. Baserga’s research focuses on the multiple roles of the type 1 insulin-like growth factor receptor (IGF-IR) in the proliferation of mammalian cells. The IGF-IR activated by its ligands is mitogenic, is required for the establishment and the maintenance of the transformed phenotype, and protects tumor cells from apoptosis. It, therefore, serves as an excellent target for therapeutic interventions aimed at inhibiting abnormal growth. In basic investigations, this group is presently studying the effects that the number of IGF-IRs and specific mutations in the receptor itself have on its ability to protect cells from apoptosis.
This investigation is strictly correlated with IGF-IR signaling, and part of this work tries to elucidate the pathways originating from the IGF-IR that are important for its functional effects. Baserga’s group has recently discovered a new signaling pathway used by the IGF-IR to protect cells from apoptosis, a unique pathway that is not used by other growth factor receptors. This pathway depends on the integrity of serines 1280-1283 in the C-terminus of the receptor, which bind 14.3.3 and cause the mitochondrial translocation of Raf-1.
Another recent discovery of this group has been the identification of a mechanism by which the IGF-IR can actually induce differentiation in certain types of cells. When cells have IRS-1 (a major substrate of the IGF-IR), the IGF-IR sends a proliferative signal; in the absence of IRS-1, the receptor induces cell differentiation. The extinction of IRS-1 expression is usually achieved by DNA methylation.
Janardan Reddy, MD
Northwestern University
The central effort of our research has been on a detailed analysis at the cellular and molecular levels of the pleiotropic responses in liver induced by structurally diverse classes of chemicals that include fibrate class of hypolipidemic drugs, and phthalate ester plasticizers, which we designated hepatic peroxisome proliferators. Our work has been central to the establishment of several principles, namely that hepatic peroxisome proliferation is associated with increases in fatty acid oxidation systems in liver, and that peroxisome proliferators, as a class, are novel nongenotoxic hepatocarcinogens.
We introduced the concept that sustained generation of reactive oxygen species leads to oxidative stress and serves as the basis for peroxisome proliferator-induced liver cancer development. Furthermore, based on the tissue/cell specificity of pleiotropic responses and the coordinated transcriptional regulation of fatty acid oxidation system genes, we postulated that peroxisome proliferators exert their action by a receptor-mediated mechanism. This receptor concept laid the foundation for the discovery of
a three member peroxisome proliferator-activated receptor (PPARalpha-, ß-, and gamma) subfamily of nuclear receptors.
PPARalpha is responsible for peroxisome proliferator-induced pleiotropic responses, including
hepatocarcinogenesis and energy combustion as it serves as a fatty acid sensor and regulates fatty acid oxidation.
Our current work focuses on the molecular mechanisms responsible for PPAR action and generation of fatty acid oxidation deficient mouse knockout models. Transcription of specific genes by nuclear receptors is a complex process involving the participation of multiprotein complexes composed of transcription coactivators.
Jose Delgado de Salles Roselino, Ph.D.
Leloir Institute, Brazil
Warburg effect, in reality “Pasteur-effect” was the first example of metabolic regulation described. A decrease in the carbon flux originated at the sugar molecule towards the end metabolic products, ethanol and carbon dioxide that was observed when yeast cells were transferred from anaerobic environmental condition to an aerobic one. In Pasteur´s works, sugar metabolism was measured mainly by the decrease of sugar concentration in the yeast growth media observed after a measured period of time. The decrease of the sugar concentration in the media occurs at great speed in yeast grown in anaerobiosis condition and its speed was greatly reduced by the transfer of the yeast culture to an aerobic condition. This finding was very important for the wine industry of France in Pasteur time, since most of the undesirable outcomes in the industrial use of yeast were perceived when yeasts cells took very long time to create a rather selective anaerobic condition. This selective culture media was led by the carbon dioxide higher levels produced by fast growing yeast cells and by a great alcohol content in the yeast culture media. This finding was required to understand Lavoisier’s results indicating that chemical and biological oxidation of sugars produced the same calorimetric results. This observation requires a control mechanism (metabolic regulation) to avoid burning living cells by fast heat released by the sugar biological oxidative processes (metabolism). In addition, Lavoisier´s results were the first indications that both processes happened inside similar thermodynamics limits.
In much resumed form, these observations indicates the major reasons that led Warburg to test failure in control mechanisms in cancer cells in comparison with the ones observed in normal cells. Biology inside classical thermo dynamics poses some challenges to scientists. For instance, all classical thermodynamics must be measured in reversible thermodynamic conditions. In an isolated system, increase in P (pressure) leads to decrease in V (volume) all this in a condition in which infinitesimal changes in one affects in the same way the other, a continuum response. Not even a quantic amount of energy will stand beyond those parameters. In a reversible system, a decrease in V, under same condition, will led to an increase in P.
In biochemistry, reversible usually indicates a reaction that easily goes from A to B or B to A. This observation confirms the important contribution of E Schrodinger in his What´s Life: “This little book arose from a course of public lectures, delivered by a theoretical physicist to an audience of about four hundred which did not substantially dwindle, though warned at the outset that the subject-matter was a difficult one and that the lectures could not be termed popular, even though the physicist’s most dreaded weapon, mathematical deduction, would hardly be utilized. The reason for this was not that the subject was simple enough to be explained without mathematics, but rather that it was much too involved to be fully accessible to mathematics.”
Hans Krebs describes the cyclic nature of the citrate metabolism. Two major research lines search to understand the mechanism of energy transfer that explains how ADP is converted into ATP. One followed the organic chemistry line of reasoning and therefore, searched how the breakdown of carbon-carbon link could have its energy transferred to ATP synthesis. A major leader of this research line was B. Chance who tried to account for two carbon atoms of acetyl released as carbon dioxide in the series of Krebs cycle reactions. The intermediary could store in a phosphorylated amino acid the energy of carbon-carbon bond breakdown. This activated amino acid could transfer its phosphate group to ADP producing ATP. Alternatively, under the possible influence of the excellent results of Hodgkin and Huxley a second line of research appears.
The work of Hodgkin & Huxley indicated the storage of electrical potential energy in transmembrane ionic asymmetries and presented the explanation for the change from resting to action potential in excitable cells. This second line of research, under the leadership of P Mitchell postulated a mechanism for the transfer of oxide/reductive power of organic molecules oxidation through electron transfer as the key for energetic transfer mechanism required for ATP synthesis. Paul Boyer could present how the energy was transduced by a molecular machine that changes in conformation in a series of 3 steps while rotating in one direction in order to produce ATP and in opposite direction in order to produce ADP plus Pi from ATP (reversibility). Nonetheless, a victorious Peter Mitchell obtained the correct result in the conceptual dispute, over the B. Chance point of view, after he used E. Coli mutants to show H gradients in membrane and its use as energy source.
However, this should not detract from the important work of Chance. B. Chance got the simple and rapid polarographic assay method of oxidative phosphorylation and the idea of control of energy metabolism that bring us back to Pasteur. This second result seems to have been neglected in searching for a single molecular mechanism required for the understanding of the buildup of chemical reserve in our body. In respiring mitochondria the rate of electron transport, and thus the rate of ATP production, is determined primarily by the relative concentrations of ADP, ATP and phosphate in the external media (cytosol) and not by the concentration of respiratory substrate as pyruvate. Therefore, when the yield of ATP is high as is in aerobiosis and the cellular use of ATP is not changed, the oxidation of pyruvate and therefore of glycolysis is quickly (without change in gene expression), throttled down to the resting state. The dependence of respiratory rate on ADP concentration is also seen in intact cells. A muscle at rest and using no ATP has very low respiratory rate.
I have had an ongoing discussion with Jose Eduardo de Salles Roselino, inBrazil. He has made important points that need to be noted.
The constancy of composition which animals maintain in the environment surrounding their cells is one of the dominant features of their physiology. Although this phenomenon, homeostasis, has held the interest of biologists over a long period of time, the elucidation of the molecular basis for complex processes such as temperature control and the maintenance of various substances at constant levels in the blood has not yet been achieved. By comparison, metabolic regulation in microorganisms is much better understood, in part because the microbial physiologist has focused his attention on enzyme-catalyzed reactions and their control, as these are among the few activities of microorganisms amenable to quantitative study. Furthermore, bacteria are characterized by their ability to make rapid and efficient adjustments to extensive variations in most parameters of their environment; therefore, they exhibit a surprising lack of rigid requirements for their environment, and appears to influence it only as an incidental result of their metabolism. Animal cells on the other hand have only a limited capacity for adjustment and therefore require a constant milieu. Maintenance of such constancy appears to be a major goal in their physiology (Regulation of Biosynthetic Pathways H.S. Moyed and H EUmbarger Phys Rev,42 444 (1962)).
A living cell consists in a large part of a concentrated mixture of hundreds of different enzymes, each a highly effective catalyst for one or more chemical reactions involving other components of the cell. The paradox of intense and highly diverse chemical activity on the one hand and strongly poised chemical stability (biological homeostasis) on the other is one of the most challenging problems of biology (Biological feedback Control at the molecular Level D.E. Atkinson Science vol. 150: 851, 1965). Almost nothing is known concerning the actual molecular basis for modulation of an enzyme`s kinetic behavior by interaction with a small molecule. (Biological feedback Control at the molecular Level D.E. Atkinson Science vol. 150: 851, 1965). In the same article, since the core of Atkinson´s thinking seems to be strongly linked with Adenylates as regulatory effectors, the previous phrases seems to indicate a first step towards the conversion of homeostasis to an intracellular phenomenon and therefore, one that contrary to Umbarger´s consideration could be also studied in microorganisms.
Most biochemical studies using bacteria, were made before the end of the third upper part of log growth phase. Therefore, they could be considered as time-independent as S Luria presented biochemistry in Life an Unfinished Experiment. The sole ingredient on the missing side of the events that led us into the molecular biology construction was to consider that proteins, a macromolecule, would never be affected by small molecules translational kinetic energy. This, despite the fact that in a catalytic environment and its biological implications S Grisolia incorporated A K Balls observation indicating that the word proteins could be related to Proteus an old sea god that changed its form whenever he was subjected to inquiry (Phys Rev v 4,657 (1964).
In D.E. Atkinson´s work (Science vol 150 p 851, 1965), changes in protein synthesis acting together with factors that interfere with enzyme activity will lead to “fine-tuned” regulation better than enzymatic activity regulation alone. Comparison of glycemic regulation in granivorous and carnivorous birds indicate that when no important nutritional source of glucose is available, glycemic levels can be kept constant in fasted and fed birds. The same was found in rats and cats fed on high protein diets. Gluconeogenesis is controlled by pyruvate kinase inhibition. Therefore, the fact that it can discriminate between fasting alone and fasting plus exercise (carbachol) requirement of gluconeogenic activity (correspondent level of pyruvate kinase inhibition) the control of enzyme activity can be made fast and efficient without need for changes in genetic expression (20 minute after stimulus) ( Migliorini,R.H. et al Am J. Physiol.257 (Endocrinol. Met. 20): E486, 1989). Regrettably, this was not discussed in the quoted work. So, when the control is not affected by the absorption of nutritional glucose it can be very fast, less energy intensive and very sensitive mechanism of control despite its action being made in the extracellular medium (homeostasis).
Component #2: Music Review and Critique as a Curation
Component #2: Detailed, below
Music Review and Critique as a Curation it represents a very fine example of Music Critique as a Curation written by Thomas Garvey on 2/8/2014 for the 1/31/2014, Celebrity Series concert in Jordan Hall by Kirill Gerstein, Component #1, above
Component #3, #4, #5, #6 – Curations in Medical Research
Component #3: Detailed, here
Work of Original Expressionwhat is the methodology of Curation in the context of Medical Research Findings Exposition of Synthesis and Interpretation of the significance of the results to Clinical Care
Dr. A. Lev-Ari‘s definition of the Methodology of Curation
Work of Original Expression of the function and use of Curation methodology for Medical Research Findings Exposition of Synthesis and Interpretation of the significance of the results to Clinical Care
Dr. JD Pearlman‘s metaphoric expression of the Curation Methodology
This volume introduces a fresh look at keeping abreast of cardiovascular disease. In particular it explains and exemplifies the how and why of curation as a methodology for discourse. Curation is designed to edify and facilitate awareness and cohesive access to biomedical knowledge otherwise buried in subspecialty scientific journals in the Life Sciences and Medicine. Particular themes of focus include discovery, innovation and translation to clinical care, including linkages and underpinnings that might otherwise be mislabeled as esoteric. Key components of curation include expert identification of data, ideas and innovations of interest, expert interpretation of the original research results, integration with context, digesting, highlighting, correlating and presenting in novel light.
The superstructure of curations includes multiple additional creative elements:
eTOCs stands for electronic Table of Contents: fresh thought-provoking organizing themes link a path to a diverse trail of publications (analogous to creating a path in the forest)
Extracts highlighting notable elements of publications that mark a path
Voice of Expert commentary providing context and direction
The Electronic Table of Contents (eTOCs) serves several functions:
eTOCs collates information from multiple sources into coherent themes
eTOCs enables multiple pathways to information, including both Longitudinal and cross-sectional organizational themes.
eTOCs presents nested pathways through the forest, including nesting of topics by overreaching theme, chapters, Curations, reports and references.
eTOCs assemblies of thought provide fresh vistas that promote innovation and rethinking
In ekistics (urban design) Francis Bacon emphasized the importance of pathways linked to purpose, recommending a landmark magnet as an attractor for pursuits along a created path. Analogously, if the continually expanding collective knowledge embodied in subspecialty publications represents a forest of data and ideas, then Curation creates pathways in that forest that serve not only to keep the reader from getting lost, but also, as recommended by Francis Bacon, creates pathways that serve attractive purposes, with special vistas, highlights, themes, coherence, motivations and purposes.
CONTEXT (for each, Causes, Risks, Biomarkers and Therapeutics): See Volumes 1,2,3,4,5,6
Component #5: Detailed, here
Work of Original Expression of two examples for the Writing Tatent and the Curation Talent applied in Medical writings by a Surgeon and by a Pathologist
Dr. A. Lev-Ari’s Curation of an article that demonstrates the Art of Praise for the Physician as a Author and Writer of proze of high literary merit on subjects in Science and Medicine:
(from Greek ἀναλογία, analogia, “proportion”[1][2]) is a cognitive process of transferring information or meaning from a particular subject (the analogue or source) to another particular subject (the target), or a linguistic expression corresponding to such a process. In a narrower sense, analogy is an inference or anargument from one particular to another particular, as opposed to deduction, induction, and abduction, where at least one of the premises or the conclusion is general. The word analogy can also refer to the relation between the source and the target themselves, which is often, though not necessarily, a similarity, as in the biological notion of analogy.
Analogy has been studied and discussed since classical antiquity by philosophers, scientists and lawyers. The last few decades have shown a renewed interest in analogy, most notably in cognitive science.
[Component #1] is analogous to [Component #6] = [Component #6] is analogous to [Component #1]
[Component #2] is analogous to [Component #4] = [Component #4] is analogous to [Component #2]
[Components #3, #5] are analogous to [Components #1, #4] and [Component #2]
Component #1: Work of Original Music Curation and Performance:
Component #2: Music Review and Critique as a Curation
Component #3: Work of Original Expression what is the methodology of Curation
Component #4: Work of Original Expression of the function and use of Curation methodology for Medical Research
Component #5: Work of Original Expression of two examples for the Writing Tatent and the Curation Talent applied in Medical writings by a Surgeon and by a Pathologist
Component #6: Music in the Service of Clinical Care
Part 3
Curation in Music (Component #1) and
Music Review as a Curation (Component #2)
Component #1: Curation in Music
Work of Original Music Curation and Performance: The Celebrity Series Concert on 1/31/2014 in Boston, MA, which I attended.
Music Review and Critique which represents a very fine example of a Curation in Music Critique written by Thomas Garvey for the 1/31/2014, Celebrity Series concert in Jordan Hall by Kirill Gerstein, Component #1, above
Rarely has a performance been curated with such subtle thematic skill as Kirill Gerstein’s at Celebrity Series last weekend.
Its calling card was the Boston premiere of current wunderkind Timo Andres’ “Old Friend,” a kind of millennial fantasia on Chopin’s Third Scherzo. You know the Chopin – it’s a dazzler split between two apparent emotional poles, one grumbling at the bottom of the keyboard, the other chiming at the top; the piece is perhaps most memorable for the sparkling arpeggios that rain over the conflicted theme that sounds at the point where the two modes meet in the middle.
Andres teases that opposition into a vast structure in “Old Friend” – but more on that later. The point I want to make now is that Andres’ title unlocks the design of Gerstein’s whole concert – or concert à clef, if you will. For the pianist had clearly taken Andres’ insight into Chopin’s scherzo as the key to his entire program, and had thought long and hard not only about the theme of “friendship” (particularly lost friendship) in life and art, but about the musical values that undergird its expression.Hence the opening choice of Haydn’s familiar Variations in F Minor. It too, of course, is a double variation: an initial melancholy voice in F minor is slowly entwined by a lighter song in F major; two “friends,” if you will, of opposed temperaments. The voices dance in ever more elaborate patterns until the second is abruptly cut off, and a coda of poignant force rings down the curtain on the piece. Legend has it that this shock was inspired by the unexpected death of Haydn’s friend Maria Anna von Genzinger, with whom he had struck up a passionate correspondence. And the Variations do have a sweetly epistolary quality; one voice seems to “reply” to the other almost by post. But Gerstein took that sense of distance a bit far; he played with a measured precision that came off as slightly dry – although the outpouring of emotion at the end of the affair, if you will, was genuine, and genuinely moving.In the next offering, Schumann’s Carnaval, the theme of friendship evoked in music was even more overt. For the program of Carnaval – now worked out by scholars from Schumann’s notes and titles – is a cavalcade of the composer’s friends, both real and imaginary, through which move two lovers, Ernestine von Fricken and Schumann’s eventual wife, Clara (along with real-life musical idols like Paganini). The piece seems structureless to the uninitiated (and, well, it is!) – but there is clearly some sort of romantic showdown at its core; many believe Schumann’s eventual rejection of Ernestine in favor of Clara is prefigured in its variations. But then Chopin shows up, and the party grinds on. I admit Carnaval never quite sustains my interest throughout its meandering length; but I also admit that Gerstein’s version was among the most compelling I’ve heard. From its opening flourish, the pianist seemed in superb control of its many voices, and even the sense of their overlapping interpenetration, and the musical haze that surrounds them. And Gerstein carried off the finale, in which the whole artsy crowd marches out to confront the Philistines, in very high style indeed.After intermission came the premiere from Andres, who delivered the most musically abstracted vision of friendship yet. Of course, this time the friend was itself a piece of music – Chopin’s scherzo (rather than the composer himself) – and music about music is almost always inherently abstract. Andres basically took the most famous feature of the scherzo – those cascades of arpeggios – and doubled them, so that “Old Friend” rippled up from the bottom of the keyboard as well as down from its top, in a series of interlocking minimalist cells drawn from Chopin’s harmonic material. The cells moved in and out of phase, and various points of intersection or inversion were constantly shifting – still, Andres seemed unable to transcend the limits of his schema, and the eventual emergence of the scherzo’s own phrases seemed like a slight anticlimax (as we could see them coming from so very far away).
Hartmann’s “Catacombs of Paris”
Thus “Old Friend” at times felt like pianism for pianists, a kind of giant tinkertoy – still, its construction was virtuosic, and its technical demands challenging indeed (the composer himself is an astonishingly facile pianist, and he clearly intended this as his own exploration of the grand manner – a kind of maximal minimalism!). For his part, Gerstein played its rumbling, chiming cadences for all they were worth; Andres wrote the piece for him, and he had to have been pleased with this performance.
Finally, galloping after the premiere came one of the great keyboard warhorses – Mussorgsky’sPictures at an Exhibition. If you’re wondering at the friendship connection here, recall that the paintings in question were by a close friend and artistic associate of the composer – the architect/artist Viktor Hartmann. And in keeping with the slightly funereal theme of much of the concert, these famous tone poems were intended as both valedictory and obituary; for the exhibition that Mussorgsky evokes (and which included works from his own collection) was, tragically, a posthumous one, as the artist died of an aneurysm at the early age of 39.
Hartmann’s “Great Gate” of Kiev was never realized.
I always make it a point to recommend that concertgoers who are only familiar with Ravel’s celebrated orchestration seek out a performance of the original score (preferably in its first form – as here – rather than Rimsky-Korsakov’s corrected edition). It’s not often heard, as its demands are punishing, particularly in the final two “pictures,” but it is an eye-opener. Perhaps inevitably, the dazzling color of the Ravel somehow spectacularizes, and perhaps even slightly de-personalizes, everything inPictures; certainly on the keyboard, for instance, it is far easier to limn the shifting response of the “Promenade” theme as it moves from vignette to vignette.
Although of course the viewer of these pictures eventually seems to step right into them; his voice first materializes deep within “Catacombs” – where perhaps he is calling to Hartmann himself – before later opening out into its own apotheosis in “The Great Gate of Kiev” (the artist’s sketch for the project, at left) – which in a way is both a gate to Heaven, through which we can imagine the artist’s spirit soaring, and a portal into the deeply Russian artistic consciousness that Mussorgsky and Hartmann dreamed of together.
To be honest, I felt that Gerstein was finally tiring a bit as the bells chimed their welcome in “Great Gate,” but it hardly mattered, as so much of his performance had proved so very exciting (perhaps it’s worth noting at this point the pianist’s own Russian roots). Just a few highlights were the subtly singing line of “The Old Castle,” the note of tragedy sounding beneath “Goldenberg and Schmuyle,” and the haunted murmur of “Con Mortuis in Lingua Mortua.” This was truly a masterly performance of a masterpiece, so no wonder the crowd called the pianist back for an encore. Gerstein chose Rachmaninoff’s Op. 3, No. 3, “Mélodie,” – a last nostalgic bouquet, simple and sweet – and perhaps meant for yet another friend cut down too soon.
Thomas Garvey – A local reviewer for several years, I was cast from my perch at the Boston Globesome time ago, but quickly learned I could write about my hometown’s culture with more freedom and accuracy on the Web than I ever could at the Globe. And as local reviews grow ever more watered-down (as the press becomes more and more desperate to hang onto advertising – and readers), it has become obvious this town needs an independent, unfettered critic who’s not interested in tossing softballs to the suburbs (or the academy), And I guess I’m just dumb enough to take the job. You can reach me with invites, praise, screeds, etc., at hubreview@hotmail.com.
Pathophysiological Effects of Diabetes on Ischemic-Cardiovascular Disease and on Chronic Obstructive Pulmonary Disease (COPD)
Curator: Larry H. Bernstein, MD, FCAP
Article ID #106: Pathophysiological Effects of Diabetes on Ischemic-Cardiovascular Disease and on Chronic Obstructive Pulmonary Disease (COPD). Published 1/15/2014
WordCloud Image Produced by Adam Tubman
This is a multipart article that develops the pathological effects of type-2 diabetes in the progression of a systemic inflammatory disease with a development of neuropathy, and fully developing into cardiovascular disease. It also identifies a systemic relationship to the development of chronic obstructive pulmonary disease (COPD).
The more we learn about diabetes, we learn about its generalized systemic effects.
This article has the following SIX Parts:
Part 1. Role of Autonomic Cardiovascular Neuropathy in Pathogenesis of ischemic heart disease in patients with diabetes mellitus
Part 2. A Longitudinal Cohort Study of the Cardiovascular Experience of Individuals at High Risk for Diabetes
Part 3. Clinical significance of cardiovascular dysmetabolic syndrome
Part 4. Waist circumference a good indicator of future risk for type 2 diabetes and cardiovascular disease
Part 5. How to use C-reactive protein in acute coronary care
Part 6. Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony
INTRODUCTION
Type 2 diabetes mellitus is a common chronic disease which develops insidiously over time, and is associated with obesity, nutritional imbalance (high fructose beverages, high starch and processed foods, carbohydrate excess intake, and an imbalance of proinflammatory to anti-inflammatory polyunsaturated fatty acids), which makes it an acquired and manageable disease. The long term effects of T2DM is played out on cardiovascular disease and stroke-risk, obstructive sleep apnea, progressive renal insufficiency, development of neuropathy, congestive heart failure and chronic obstructive pulmonary disease, all of which are occuring related to an systemic inflammatory condition that proceeds for some time prior to the identification of overt diabetes.
A detailed story of a significant part of these associations continues in the SIX Part series.
Part 1. Role of Autonomic Cardiovascular Neuropathy in Pathogenesis of ischemic heart disease in patients with diabetes mellitus
This article is an abstract only of a related publication of the pathogenesis of autonomic neuropathy in diabetics leading to ischemic heart disease.
Diabetes is strongly associated with macrovascular complications, among which
ischemic heart disease is the major cause of mortality.
Autonomic neuropathy increases the risk of complications, which calls for an early diagnosis. The aim of this study was to determine
both presence and extent of cardiac autonomic neuropathy,
in regard to the type of diabetes mellitus, as well as
its correlation with coronary disease and
major cardiovascular risk factors.
Material and methods. We have examined 90 subjects, classified into three groups, with 30 patients each: those with type 1 diabetes, type 2 diabetes and control group of healthy subjects. All patients underwent
cardiovascular tests (Valsalva maneuver, deep breathing test, response to standing, blood pressure response to standing sustained, handgrip test),
electrocardiogram,
treadmill exercise test and
filled out a questionnaire referring to major cardiovascular risk factors: smoking, obesity, hypertension, and dyslipidemia.
Results. Our results showed that cardiovascular autonomic neuropathy was
more frequent in type 2 diabetes,
manifesting as autonomic neuropathy.
In patients with autonomic neuropathy, regardless of the type of diabetes,
the treadmill test was positive, i.e. strongly correlating with coronary disease.
In regard to coronary disease risk factors,
the most frequent correlation was found for obesity and hypertension.
Discussion
Cardiovascular autonomic neuropathy is considered to be the principal cause of arteriosclerosis and coronary disease. Our results showed that the occurrence of cardiovascular autonomic neuropathy increases the risk of coronary disease due to dysfunction of autonomic nervous system.
Conclusions
Cardiovascular autonomic neuropathy is a common complication of diabetes that significantly correlates with coronary disease. Early diagnosis of cardiovascular autonomic neuropathy points to increased cardiovascular risk, providing a basis for preventive and therapeutic measures.
Part 2. A Longitudinal Cohort Study of the Cardiovascular Experience of Individuals at High Risk for Diabetes
This second part is a description of a longitudinal cohort study of individuals at high-risk for diabetes. Unlike the SSA study, the study is not focused on protein-energy malnutrition.
Protocol for ADDITION-PRO: a longitudinal cohort study of the cardiovascular experience of individuals at high risk for diabetes recruited from Danish primary care
Subjects: Public aspects of medicine, Medicine, Public Health, Health Sciences
Authors: Johansen NB, Hansen Anne-Louise S, Jensen TM, Philipsen A, Rasmussen SS, Jørgensen ME, Simmons RK, Lauritzen T, Sandbæk A, Witte DR
Publisher: BioMed Central Date of publication: 2012 Dec Published in: BMC Public Health 2012; 12(1): 1078 ISSN(s): 1471-2458 Added to DOAJ: 2013-03-12 http://dx.doi.org/10.1186/1471-2458-12-1078 http://www.biomedcentral.com/1471-2458/12/1078
Keywords: Diabetes, Cardiovascular disease, Primary care, Complications, Microvascular, Impaired fasting glucose, Impaired glucose intolerance, Aortic stiffness, Physical activity, Body composition
Background
Screening programmes for type 2 diabetes inevitably find more individuals at high risk for diabetes than people with undiagnosed prevalent disease. While well established guidelines for the treatment of diabetes exist, less is known about treatment or prevention strategies for individuals found at high risk following screening. In order to make better use of the opportunities for primary prevention of diabetes and its complications among this high risk group, it is important to
quantify diabetes progression rates and to examine
the development of early markers of cardiovascular disease and
microvascular diabetic complications.
We also require a better understanding of the
mechanisms that underlie and drive early changes in cardiometabolic physiology.
The ADDITION-PRO study was designed to address these issues among individuals at different levels of diabetes risk recruited from Danish primary care.
Methods/Design
ADDITION-PRO is a population-based, longitudinal cohort study of individuals at high risk for diabetes. 16,136 eligible individuals were identified at high risk following participation in a stepwise screening programme in Danish general practice between 2001 and 2006.
All individuals with impaired glucose regulation at screening,
those who developed diabetes following screening, and
a random sub-sample of those at lower levels of diabetes risk
were invited to attend a follow-up health assessment in 2009–2011 (n = 4,188), of whom 2,082 (50%) attended. The health assessment included
detailed measurement of anthropometry,
body composition,
biochemistry,
physical activity and
cardiovascular risk factors including aortic stiffness and central blood pressure.
All ADDITION-PRO participants are being followed for incident cardiovascular disease and death.
Discussion
The ADDITION-PRO study is designed to increase
understanding of cardiovascular risk and
its underlying mechanisms among individuals at high risk of diabetes.
Key features of this study include
(i) a carefully characterised cohort at different levels of diabetes risk;
(ii) detailed measurement of cardiovascular and metabolic risk factors;
(iii) objective measurement of physical activity behaviour; and
(iv) long-term follow-up of hard clinical outcomes including mortality and cardiovascular disease.
Results will inform policy recommendations concerning cardiovascular risk reduction and treatment among individuals at high risk for diabetes. The detailed phenotyping of this cohort will also allow a number of research questions concerning early changes in cardiometabolic physiology to be addressed.
Part 3. Clinical significance of cardiovascular dysmetabolic syndrome
This study also addresses the issue of diabetes insulin resistance leading to cardiovascular dysmetabolic syndrome.
Subjects: Diseases of the circulatory (Cardiovascular) system,
Specialties of internal medicine, Internal medicine, Medicine, Cardiovascular, Medicine (General), Health Sciences
Authors: Deedwania Prakash C Publisher: BioMed Central Date of publication: 2002 Jan
Published in: Trials 2002; 3: 1(2) ISSN(s): 1468-6708 Added to DOAJ: 2004-06-03 http://dx.doi.org/10.1186/1468-6708-3-2 http://cvm.controlled-trials.com/content/3/1/2
Although diabetes mellitus is predominantly a metabolic disorder,
recent data suggest that it is as much a vascular disorder.
Cardiovascular complications are the leading cause
of death and disability in patients with diabetes mellitus.
A number of recent reports have emphasized that
many patients already have atherosclerosis in progression
at the time they are diagnosed with clinical evidence of diabetes mellitus.
The increased risk of atherosclerosis and cardiovascular complications in diabetic patients is related to
the frequently associated dyslipidemia, hypertension, hyperglycemia, hyperinsulinemia, and endothelial dysfunction.
The evolving knowledge regarding the variety of
metabolic,
hormonal, and
hemodynamic abnormalities in patients with diabetes mellitus
has led to efforts designed for early identification of individuals at risk of subsequent disease. It has been suggested that
insulin resistance, the key abnormality in type II diabetes,
often precedes clinical features of diabetes by 5–6 years.
Careful attention to the criteria described for the cardiovascular dysmetabolic syndrome
should help identify those at risk at an early stage.
The application of nonpharmacologic as well as newer emerging pharmacologic therapies can have beneficial effects
in individuals with cardiovascular dysmetabolic syndrome and/or diabetes mellitus
by improving insulin sensitivity and related abnormalities.
Early identification and implementation of appropriate therapeutic strategies would be necessary
to contain the emerging new epidemic of cardiovascular disease related to diabetes.
Part 4. Waist circumference a good indicator of future risk for type 2 diabetes and cardiovascular disease
Subjects: Public aspects of medicine, Medicine, Public Health, Health Sciences
Authors: Siren Reijo, Eriksson Johan G, Vanhanen Hannu
Publisher: BioMed Central Date of publication: 2012 Aug
Published in: BMC Public Health 2012; 12: 1(631) ISSN(s): 1471-2458 Added to DOAJ: 2013-03-12 http://dx.doi.org/10.1186/1471-2458-12-631 http://www.biomedcentral.com/1471-2458/12/631
Keywords: Waist circumference, Type 2 diabetes, Cardiovascular disease, Middle-aged men
Background
Abdominal obesity is a more important risk factor than overall obesity in
predicting the development of type 2 diabetes and cardiovascular disease.
From a preventive and public health point of view it is crucial that
risk factors are identified at an early stage,
in order to change and modify behaviour and lifestyle in high risk individuals.
Methods
Data from a community based study was used to assess
the risk for type 2 diabetes,
cardiovascular disease and
prevalence of metabolic syndrome in middle-aged men.
In order to identify those with increased risk for type 2 diabetes and/or cardiovascular disease
sensitivity and specificity analysis were performed, including
calculation of positive and negative predictive values, and
corresponding 95% CI for eleven different cut-off points,
with 1 cm intervals (92 to 102 cm), for waist circumference.
Results
A waist circumference ≥94 cm in middle-aged men,
identified those with increased risk for type 2 diabetes
and/or for cardiovascular disease
with a sensitivity of 84.4% (95% CI 76.4% to 90.0%), and a specificity of 78.2% (95% CI 68.4% to 85.5%). The positive predictive value was 82.9% (95% CI 74.8% to 88.8%), and negative predictive value 80.0% (95% CI 70.3% to 87.1%), respectively .
Conclusions
Measurement of waist circumference in middle-aged men
is a reliable test to identify individuals at increased risk for type 2 diabetes and cardiovascular disease.
This measurement should be used more frequently in daily practice in primary care
in order to identify individuals at risk and when planning health counselling and interventions.
Part 5. How to use C-reactive protein in acute coronary care
Luigi M. Biasucci, Wolfgang Koenig, Johannes Mair, Christian Mueller, Mario Plebani, Bertil Lindahl, Nader Rifai,Per Venge,Christian Hamm, and the Study Group on Biomarkers in Cardiology of the Acute Cardiovascular Care Association of the European Society of Cardiology
Department of Cardiology B, Aarhus University Hospital, Tage Hansens Gade2, Aarhus DK-8000,Denmark; Germany, U.K., U.S., Italy
European Heart Journal Advance Access published Nov 7, 2013. Current Opinion. http://dx.doi.org/10.1093/eurheartj/eht435
Introduction
C-reactive protein (CRP) is an acute phase protein and an established marker for detection, risk stratification, and monitoring of infections, and inflammatory and necrotic processes.. Because C-reactive protein is sensitive but not specific, its values must be nterpreted in the clinical context. Inpatients with acute myocardial infarction (AMI), CRP increases within 4–6h of symptoms, peaks 2–4 days later,and returns to baseline after 7–10 days.
CRP has gained interest recently as a marker for risk stratification in acute coronary syndrome (ACS) when measured by high-sensitivity CRP assays. These assays have greater analytical sensitivity and reliably measure CRP concentrations within the reference range with low imprecision (5–10%). Because of evidence that atherosclerosis is an inflammatory disease, high-sensitivity CRP can be used as a biomarker of risk
in primary prevention and in patients with known cardiovascular disease. The aim of this review is to evaluate the use of CRP in patients with acute coronary disease.
The in-vitro stability of high-sensitivity C-reactive protein is excellent. Specific blood sampling conditions aren’t necessary. However, retesting may be necessary with some assays if there is marked lipaemia. Baseline and subsequent measures are in good for agreement for risk stratification despite biological variability of 30–60%.
The upper reference limit is method-dependent but usually 8mg/L for standard assays. The distribution of high-sensitivity CRP concentrations is skewed in both genders with a 50th percentile of_1.5mg/L (excluding women on hormone replacement therapy). Race differences have been reported. Most studies have reported no relationship with age, but to circadian and seasonal variation. CRP concentrations are increased by smoking, obesity, and hormone replacement therapy and reduced by exercise, moderate alcohol drinking, and statin use. Correction for these factors is essential in reference range studies. CRP assays are not standardized. We recommend the use of third-generation high-sensitivity CRP assays that combine features of standard and high-sensitivity CRP assays. Required assay precision should be < 10% in the range of 3 and 10 mg/L.
Biochemical and analytical issues
Critical clinical concepts
(1) CRP concentrations are reported in mg/L
(2) CRP test results are method-dependent
classification of patients into risk categories is usually comparable
(3) Third generation CRP assay are recommended
(4) No specific patient preparation before blood sampling is necessary
(5) The in-vitro stability of CRP is high
This is only a portion of the published concensus document. What is relevant to this discussion is that the hs-CRP is an extremely valuable marker for inflammatory disease. It is not ordered often enough because of the broad range of values that we have become accustomed to for years, and it is elevated in rheumatologic conditions, but even then, it is widely used in pediatrics because children may present with rapidly emergent sepsis with very minimal sympoms.
The hs-CRP has opened a window to subliminal inflammatory disease that is diabetes, with accompanied arteriolar endothelial inflammation.
Part 6. Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony
Subjects: Diseases of the circulatory (Cardiovascular) system,
Specialties of internal medicine, Internal medicine, Medicine, Cardiovascular, Medicine (General), Health Sciences
Authors: Mirrakhimov Aibek E
Publisher: BioMed Central Date of publication: Oct 2012 ISSN(s): 1475-2840
Published in: Cardiovascular Diabetology 2012; 11(1):132 Added to DOAJ: 2013-03-12 http://dx.doi.org/10.1186/1475-2840-11-132http://www.cardiab.com/content/11/1/132
Chronic obstructive pulmonary disease, metabolic syndrome and diabetes mellitus
are common and underdiagnosed medical conditions.
It was predicted that chronic obstructive pulmonary disease
will be the third leading cause of death worldwide by 2020.
The healthcare burden of this disease is even greater
if we consider the significant impact of chronic obstructive pulmonary disease on
the cardiovascular morbidity and mortality.
Chronic obstructive pulmonary disease
may be considered as a novel risk factor for new onset type 2 diabetes mellitus via
multiple pathophysiological alterations such as:
inflammation and oxidative stress,
insulin resistance,
weight gain and
alterations in metabolism of adipokines.
On the other hand, diabetes may act as an independent factor,
negatively affecting pulmonary structure and function.
Diabetes is associated with an increased risk of
pulmonary infections,
disease exacerbations and
worsened COPD outcomes.
On the top of that, coexistent OSA
may increase the risk for type 2 DM in some individuals.
The current scientific data necessitate a greater outlook on chronic obstructive pulmonary disease and
chronic obstructive pulmonary disease may be viewed as a risk factor for
the new onset type 2 diabetes mellitus.
Conversely, both types of diabetes mellitus should be viewed as
strong contributing factors for the development of obstructive lung disease.
Such approach can potentially improve the outcomes and medical control for both conditions,
and, thus, decrease the healthcare burden of these major medical problems.
CONCLUSIONS
This discussion presents a spectrum of cardiovascular risk associated with type 2 diabetes mellitus, with high risk for CVD, stroke, endothelial dysfunction, and an association with obesity, measured by waist circumference, and an underlying proinflammatory state that can be measured by CRP.
2012pharmaceutical
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