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Archive for the ‘Reproductive Biology & Bio Instrumentation’ Category

 

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

An estimated 10 to 15% of couples suffer from infertility, and many treatment decisions rely on trial and error. A team of international scientists has found a common genetic variant which may explain why some men with normal sperm counts and good quality sperm are affected by infertility.

The study findings suggested that men with a variation in a gene which codes for a sperm-coating protein called beta defensin 126 (DEFB126) have a reduction in the protein coat on the outside of the sperm which makes it difficult for the sperm to ‘swim’ to the egg.

Dr Edward Hollox of the University of Leicester and co-author of the study said: ‘If you’ve got this gene variant you should allow that little bit longer if your partner’s planning to get pregnant’. The researchers, including scientists from the University of California and the Anhui Medical University in China, carried out the study on over 500 newly-wed Chinese couples who were trying for a baby.

They found that when men’s sperm lacked a coat of the DEFB126 protein, their wives were significantly less likely than expected to become pregnant.

Previous studies have shown that two copies of the genetic variant may be found in up to one quarter of men around the world, with about half of all men having one copy. The DEFB126 protein coat helps sperm to swim through cervical mucus and evade the woman’s immune system, as well as enabling it to attach to the walls of fallopian tubes.

The study showed, however, that men with two copies of the variant produced sperm that were less able to swim through a substitute to cervical mucus, hyaluronic acid gel. In macaques, it has already been shown that this protein is important in evading the immune system and the researchers believe the protein coat plays the same role in humans. Commenting on the study, Dr Allan Pacey, senior lecturer in Andrology at the University of Sheffield, said: ‘We actually understand very little about the subtle molecular events which occur in sperm as they make their journey through the woman’s body to fertilise an egg’. The research was published in the journal Science Translational Medicine. If replicated in future studies, these findings promise to guide choices about the timing and type of assisted reproduction interventions—and further hint at the possibility of treating sperm from del/del homozygotes to promote fertility.

A gene which helps sperm bind to an egg has been identified by scientists. Sperm-to-egg binding is an essential process during fertilization and although the preliminary studies were performed on mice, the gene may represent a new target for infertility treatments. Sperm from mice that had the gene switched off were only able to fertilise eggs from female mice three percent of the time compared to 80 percent fertilisation success in normal mice.

The gene codes for a protein called PDILT which helps another gene product to form and assemble correctly and then to reach the surface of a sperm. Once this happens the sperm is able to navigate the uterus and oviduct and penetrate the sticky outer layers of an egg. The study, which is published in PNAS (Proceedings of the National Academy of Sciences), also demonstrates the importance of cumulus cells, a cluster of cells that surround and protect the egg, as their presence allows sperm to bind to their target. Sperm from mice that had their PDILT gene switched off would not bind to a bare egg, but would bind to an egg surrounded by cumulus cells.

Co-author Dr Adam Benham from Durham University in the UK said that the PDILT protein is ‘an essential part of the navigation system of sperm. Like any navigation system, you have to programme where it is that you want to go and this protein plays an essential role in getting sperm to the right destination, in good shape, and in good time’. A question now for the scientists is whether the PDILT gene has as much importance in human fertility as it does in mice. ‘Mutations in the gene may be responsible for unexplained male fertility problems and further research may aid more effective IVF treatment‘, said Dr Benham.

Source References:

http://stm.sciencemag.org/content/3/92/92ps31.abstract

http://www.bionews.org.uk/page_142955.asp

http://www.itv.com/news/update/2012-05-01/scientists-discover-new-gene-key-to-fertility/

http://www.bionews.org.uk/page_102705.asp

 

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Reporter: Aviva Lev-Ari, PhD, RN

 

 

Study Counters WHI on Heart Risk of Hormones in Menopause

By Crystal Phend, Senior Staff Writer, MedPage Today

Published: October 03, 2012

 

 

 

 

Hormone therapy may actually help the heart in some respects for newly menopausal women, a randomized trial showed, although the impact on hard outcomes like stroke and breast cancer still remains to be seen.

Oral estrogen plus progesterone improved lipid levels, while a transdermal patch improved insulin sensitivity in the KEEPS trial, according to researchers led by S. Mitchell Harman, MD, PhD, of the nonprofit Kronos Longevity Research Institute, which sponsored the trial.

Neither combination hormone treatment altered atherosclerosis progression or raised blood pressure, according to a Kronos press release summarizing a report to be presented Wednesday at the North American Menopause Society meeting in Orlando.

“The results provide reassurance for women who are recently menopausal and taking hormone therapy for short-term treatment of menopausal symptoms,” the group concluded in the release.

The need for reassurance stems from results released a decade ago from the Women’s Health Initiative (WHI), which showed an elevated risk of cardiovascular disease, stroke, and thromboembolic events as well as breast cancer with estrogen plus progestin.

Subsequent studies largely affirmed those risks and pointed to others, including ovarian cancer, lung cancer mortality, and probable dementia.

Menopause organizations largely recommended “the lowest dose for the shortest time” but have started backing away from that stance, instead endorsing a more flexible approach based on type and timing of hormone therapy.

Contradiction or Clarification?

The new study didn’t show significant differences in adverse events between women taking oral or transdermal estrogen with progesterone and those on placebo, including:

  • Breast cancer
  • Endometrial cancer
  • Myocardial infarction
  • Transient ischemic attack
  • Stroke
  • Venous thromboembolic disease

“However, the absolute numbers of such events were extremely small in all three treatment groups, making definitive conclusions impossible,” the researchers acknowledged.

Nor is the KEEPS study ever likely to definitively determine safety, because it was too small to assess clinical events, session moderator and presenter JoAnn E. Manson, MD, DrPH, commented in an email to ABC News and MedPage Today.

But that wasn’t the point of the trial, said Manson, who serves as chief of preventive medicine at Brigham and Women’s Hospital in Boston and is outgoing president of the menopause society.

“The KEEPS trial does not challenge the conclusions of WHI about the risks of clinical events with hormone therapy,” she wrote. “KEEPS and WHI were addressing entirely different questions.”

The earlier study tested hormone therapy as it was in clinical use at the time, for cardiovascular prevention based on epidemiologic suggestion of benefit.

The evidence has clearly come down against hormone therapy for that use, Manson noted.

The question that KEEPS is now answering is how perimenopausal women should approach management of menopausal symptoms — if relatively short periods of hormone therapy are safe, noted Sharonne N. Hayes MD, of the Women’s Heart Clinic at the Mayo Clinic in Rochester, Minn.

So it may be enough that these risks weren’t substantially elevated in the trial, several experts contacted by ABC and MedPage Today agreed.

“The safety of HRT in this newly menopausal population is very reassuring and will likely increase usage as well as demand for HRT in women suffering with vasomotor symptoms,” commented neurologist Cynthia L. Harden, MD, of the North Shore-Long Island Jewish Health System in Great Neck, N.Y., who said the KEEPS data adds nuance rather than contradiction.

The results don’t change the post-WHI clinical approach of yearly reassessment targeting discontinuation after a few years of hormone therapy, added Wendy Vitek, MD, an ob/gyn at the University of Rochester Medical Center in Rochester, N.Y.

Different Populations, Different Drugs

There were some differences between the Women’s Health Initiative and the KEEPS trial that may lead to real differences in outcome, though, researchers suggested.

The KEEPS trial included 727 healthy women ages 42 to 58 who were all within 3 years of the onset of menopause at baseline.

The mean age was 52, whereas the vast majority of women in the nine hormone therapy trials done to date, including the WHI, were in their 60s.

KEEPS randomized its newly-menopausal population to double-blind treatment with cyclical micronized progesterone (Prometrium) plus one of the following:

  •  

    Oral conjugated equine estrogen (Premarin) given at 0.45 mg/day, which was lower than the 0.625 mg/d used in the WHI

  •  

    Transdermal estradiol (Climara) at 50 µg/day, an option not available in the WHI

  • Placebo

 

Even the two different estrogen administration routes showed some differential effects on cardiovascular risk factors, the investigators pointed out.

HDL cholesterol and triglycerides rose while LDL fell with the oral estrogen.

The patch didn’t affect any lipid levels, but it did lower insulin resistance, which the oral form did not.

Neither drug boosted systolic or diastolic blood pressure, unlike the blood pressure increases seen with oral estrogen in the WHI.

Atherosclerosis neither accelerated nor reversed with 48 months of either treatment as monitored by carotid ultrasound, although there was a nonsignificant trend for less coronary artery calcium accumulation compared with placebo, noted Harman, who also practices at the Phoenix VA Medical System.

But that’s not necessarily reassuring with regard to cardiovascular outcomes for this younger group of women, Jacques Rossouw, MBChB, MD, chief of the WHI Branch of the National Heart, Lung and Blood Institute, noted in an email to ABC and MedPage Today.

“Changes in arteries in younger women have little relation to risk of stroke,” he explained. “Estrogen/progestin have [effects] on clotting mechanisms, on inflammation mechanisms. Those are things that trigger acute heart attack or stroke [in younger women]. Perfectly healthy young women can have strokes but have completely normal arteries. ”

Really, “the lack of effect on atherosclerosis reinforces the results of the WHI that hormone therapy is not good preventive therapy for heart disease,” added Lewis H. Kuller, MD, DrPH, of the University of Pittsburgh.

 

As expected, hormone therapy cut down on hot flashes and night sweats while raising bone density and mood, co-investigator Sanjay Asthana, MD, of the University of Wisconsin in Madison, said in the Kronos press release.

Sexual function also improved compared with placebo, in accord with the reduction in vaginal dryness although not the lack of improvement in sex drive seen in prior studies.

“KEEPS also highlights the need for individualized decision making about hormone therapy, given that oral conjugated equine estrogen and transdermal estradiol may have different profiles of effects, and different women have different symptom profiles and priorities for treatment,” the researchers noted in the press release.

KEEPS Sponsor Biased?

Kronos has long had an openly declared interest in countering the 2002 WHI findings of increased health risks from postmenopausal hormone therapy. In 2007, it issued a series of press releases attacking the WHI conclusions and touting KEEPS — one of which included a synopsis describing the nascent trial as “one of the studies to refute the WHI.”

The money behind Kronos comes from the Aurora Foundation. The latter was established by John Sperling, the billionaire founder of the University of Phoenix and other for-profit education ventures.

About 90% of Kronos’ $5.3 million in funding in 2010, the last year for which public records are available, came from Aurora. The $4.8 million given to Kronos that year was more than half of Aurora’s total giving.

Sperling, who is the foundation’s sole trustee, has a long history of involvement in sometimes controversial biological research involving life extension. He funded a successful, multimillion-dollar effort to clone his girlfriend’s dog in 2007, and later a similar cloning project for house cats.

Previously, he had bankrolled a medical clinic in a Phoenix suburb called the Kronos Group — not related to the Kronos Longevity Research Institute — that offered anti-aging remedies to older patients. It has since morphed into Kronos Optimal Health, which markets relatively conventional health and wellness programs to employers and individuals.

2004 article in Wired magazine reported that Sperling had also invested in a group of biotechnology companies seeking to develop anti-aging technologies based on cloning and stem cells.

The study was sponsored by the Kronos Longevity Research Institute with funding from the National Institutes of Health for the ancillary cognitive and affective portion.

The presentation was supported by grant funding from Noven Pharmaceuticals.

This article was developed in collaboration with ABC News. 

 

Primary source: North American Menopause Society
Source reference:
Manson JE, et al “New findings from the Kronos early estrogen prevention study (keeps) Randomized trial” NAMS2012.


Crystal Phend

Staff Writer

Crystal Phend joined MedPage Today in 2006 after roaming conference halls for publications including The Medical PostOncology TimesDoctor’s Guide, and the journal IDrugs. When not covering medical meetings, she writes from Silicon Valley, just south of the San Francisco fog.

SOURCE:

http://www.medpagetoday.com/MeetingCoverage/NAMS/35106?utm_source=breaking-news&utm_medium=email&utm_campaign=breaking-news

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Calcium Dependent NOS Induction by Sex Hormones: Estrogen

Reporter and Curator:  Sudipta Saha, Ph.D.

Nitric oxide (NO) synthases (NOSs) constitute a family of isozymes that catalyze the oxidation of L-arginine to NO and citrulline. First identified in the vascular endothelium, NO synthesis has subsequently been shown to play important roles in:

  • the regulation of vascular and gastrointestinal tone,
  • in cell-mediated cytotoxicity against bacteria and tumors, and
  • in a variety of central and peripheral nervous system activities.

NOSs can be divided into three functional classes based on their sensitivity to calcium.

  • The cytokine- or bacterial product-inducible isoenzyme iNOS binds calmodulin tightly at resting intracellular calcium concentrations.
  • The constitutive forms, isozymes eNOS (originally described in endothelial cells) and
  • nNOS (originally described in neuronal tissue), bind calmodulin in a reversible and calcium-dependent fashion.

The mechanisms by which their synthesis is controlled are unknown. The cDNA species encoding the rat, mouse, and human nNOS, the human and bovine eNOS, and iNOS from several species and cell types have been cloned and sequenced. The three human isozymes characterized to date are distinct, with their deduced protein sequences showing only 50-60%o amino acid identity. nNOS, which in rats and humans localizes to neurons in the central and peripheral nervous system and colocalizes with NADPHdiaphorase activity, has also been shown to be widely distributed in several non-neuronal tissues including human skeletal muscle.

It had been thought that both nNOS and eNOS were purely constitutive enzymes, although studies suggest eNOS may be induced by shear stress. Studies demonstrate that these NOSs can be induced in several tissues during pregnancy and in nonpregnant female and male animals by estradiol and that in skeletal muscle it is accompanied by an increase in NOS-specific mRNA.

Evidences emerging from various laboratories showed that there is an increase in the release of NO from the vasculature during pregnancy. Furthermore, treatment of pregnant animals at the end of gestation with tamoxifen reduced NOS activity in the cerebellum, an organ where tamoxifen acts as a pure estrogen-receptor antagonist. Thus, the increase in calcium-dependent NOS activity during pregnancy is mediated by estrogen. This conclusion is supported by the fact that treatment of nonpregnant females and male animals with estradiol also increased calcium-dependent NOS activity in all tissues studied.

Interestingly, testosterone treatment also increased cerebellar NOS activity without affecting other tissues. However, testosterone may increase brain NOS by directly binding estrogen receptors as has been reported. Furthermore, the cerebellum was the only tissue in the male to respond to a 5-day course of estradiol, suggesting that it may have a larger number and/or a greater availability of estrogen receptors than other tissues. In addition, the brain is rich in aromatase, which converts testosterone into estradiol. This, together with the observation that progesterone does not induce NOS, indicates that the induction of both nNOS and eNOS is specific for estrogen and not a characteristic of all sex steroids. These experiments do not exclude the possibility that the addition of progesterone might modify the estradiol effect.

The increases in NOS activity are the result of augmented enzyme synthesis (enzyme induction) since they are accompanied by increases in the specific mRNAs for both eNOS and nNOS. It is not, however, possible to tell whether the increases in mRNA are caused by an upregulation of mRNA synthesis (transcriptional induction) or decreased mRNA breakdown.

Although calcium-dependent NOS activity was increased by estradiol in tissues obtained from both female and male guinea pigs, a longer duration of treatment was necessary in the male. The most likely explanation for this observation is that the number or availability of estrogen receptors is initially too low in most tissues of the male and requires a period of estrogen priming. Although other factors may play a role, the duration of exposure may well explain the observation that the effect of pregnancy on NOS-specific mRNA is greater than estradiol alone.

The observation that estradiol induces calcium-dependent NOSs has several important implications:

  • An increase in release of NO from the endothelium would decrease vascular tone and contractility, events that are characteristic in pregnancy.
  • Heterogeneity among tissue endothelium regarding the effects of estrogen on basal NO release could explain the selective redistribution of maternal cardiac output to organs important for a successful pregnancy.
  • Consistent with this possibility is the observation that the effect of pregnancy on endothelium-derived NO is greatest in the uterine artery, followed by the mesenteric artery and then renal arteries.
  • An alternative hypothesis to explain the adaptation of smooth muscle to pregnancy is that it is caused by prostacyclin. Prostacyclin is increased during pregnancy and contributes to the observed reduced contractility of the ovine uterine artery to angiotensin II.

However, estradiol does not increase the synthesis of prostacyclin by the endothelium, nor does inhibition of prostacyclin synthesis prevent the effects of pregnancy on smooth muscle. In addition, both the incidence of esophageal reflux and the gastrointestinal transit time are increased during pregnancy. Although this phenomenon has previously been attributed to a direct effect of progesterone, NO is a powerful dilator of the gastrointestinal smooth muscle. If the increase in NOS activity observed in the esophagus applies to the bowel, enhanced NO might be the mechanism underlying both increased esophageal reflux and transit time.

The biological signifcance of an estradiol-dependent increase in the NOS in the central nervous system is of great interest and deserves further investigation. Furthermore, an estradiol-mediated increase in NOS in the vasculature could be the mechanism whereby premenopausal women are protected from coronary artery disease since increased NOS may slow the development of atherosclerosis and reduce the contractile response to acute thrombosis. Finally, the induction of calcium-dependent NOS enzymes by estradiol suggests that the present classification of this family of enzymes into constitutive and inducible types needs to be revised, since eNOS and nNOS enzymes at least are both constitutive and inducible.

Source References:

http://www.ncbi.nlm.nih.gov/pubmed?term=Calcium%20dependent%20NOS%20induction%20by%20sex%20hormones

Other research published on Nitric Oxide on this Scientific Web Site include the following:

Nitric Oxide in bone metabolism July 16, 2012

Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/16/nitric-oxide-in-bone-metabolism/?goback=%2Egde_4346921_member_134751669

 

Nitric Oxide production in Systemic sclerosis July 25, 2012

Curator: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/07/25/nitric-oxide-production-in-systemic-sclerosis/?goback=%2Egde_4346921_member_138370383

Nitric Oxide Signalling Pathways August 22, 2012 by

Curator/ Author: Aviral Vatsa, PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/22/nitric-oxide-signalling-pathways/?goback=%2Egde_4346921_member_151245569

Nitric Oxide: a short historic perspective August 5, 2012

Author/Curator: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/05/nitric-oxide-a-short-historic-perspective-7/

 

Nitric Oxide: Chemistry and function August 10, 2012

Curator/Author: Aviral Vatsa PhD, MBBS

http://pharmaceuticalintelligence.com/2012/08/10/nitric-oxide-chemistry-and-function/?goback=%2Egde_4346921_member_145137865

Nitric Oxide and Platelet Aggregation August 16, 2012 by

Author: Dr. Venkat S. Karra, Ph.D.

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/?goback=%2Egde_4346921_member_147475405

 

The rationale and use of inhaled NO in Pulmonary Artery Hypertension and Right Sided Heart Failure August 20, 2012

Author: Larry Bernstein, MD

http://pharmaceuticalintelligence.com/2012/08/20/the-rationale-and-use-of-inhaled-no-in-pulmonary-artery-hypertension-and-right-sided-heart-failure/

Nitric Oxide: The Nobel Prize in Physiology or Medicine 1998 Robert F. Furchgott, Louis J. Ignarro, Ferid Murad August 16, 2012

Reporter: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/16/nitric-oxide-the-nobel-prize-in-physiology-or-medicine-1998-robert-f-furchgott-louis-j-ignarro-ferid-murad/

 

Coronary Artery Disease – Medical Devices Solutions: From First-In-Man Stent Implantation, via Medical Ethical Dilemmas to Drug Eluting Stents August 13, 2012

Author: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/08/13/coronary-artery-disease-medical-devices-solutions-from-first-in-man-stent-implantation-via-medical-ethical-dilemmas-to-drug-eluting-stents/

Cardiovascular Disease (CVD) and the Role of agent alternatives in endothelial Nitric Oxide Synthase (eNOS) Activation and Nitric Oxide Production July 19, 2012

Curator and Research Study Originator: Aviva Lev-Ari, PhD, RN

http://pharmaceuticalintelligence.com/2012/07/19/cardiovascular-disease-cvd-and-the-role-of-agent-alternatives-in-endothelial-nitric-oxide-synthase-enos-activation-and-nitric-oxide-production/

Macrovascular Disease – Therapeutic Potential of cEPCs: Reduction Methods for CV Risk

An Investigation of the Potential of circulating Endothelial Progenitor Cells (cEPCs) as a Therapeutic Target for Pharmacological Therapy Design for Cardiovascular Risk Reduction: A New Multimarker Biomarker Discovery

Curator: Aviva Lev-Ari, PhD, RN, July 12, 2012

http://pharmaceuticalintelligence.com/2012/07/02/macrovascular-disease-therapeutic-potential-of-cepcs-reduction-methods-for-cv-risk/

 

Bone remodelling in a nutshell June 22, 2012

Author: Aviral Vatsa, Ph.D., MBBS

http://pharmaceuticalintelligence.com/2012/06/22/bone-remodelling-in-a-nutshell/

Targeted delivery of therapeutics to bone and connective tissues: current status and challenges – Part 1

AuthorL Aviral Vatsa, PhD, September 23, 2012

http://pharmaceuticalintelligence.com/2012/09/23/targeted-delivery-of-therapeutics-to-bone-and-connective-tissues-current-status-and-challenges-part-i/

Calcium dependent NOS induction by sex hormones: Estrogen

Curator: S. Saha, PhD, October 3, 2012

http://pharmaceuticalintelligence.com/2012/10/03/calcium-dependent-nos-induction-by-sex-hormones/

 

Nitric Oxide and Platelet Aggregation

Author V. Karra, PhD, August 16, 2012

http://pharmaceuticalintelligence.com/2012/08/16/no-and-platelet-aggregation/

Bystolic’s generic Nebivolol – positive effect on circulating Endothelial Progenitor Cells endogenous augmentation

Curator: Aviva Lev-Ari, PhD, July 16, 2012

http://pharmaceuticalintelligence.com/?s=Nebivolol

 

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

Targeting a protein important for chromatin organization could be a new strategy for male birth control. Proper regulation of chromatin dynamics is critical for proper sperm development, and mice with alterations in a protein that is central to chromatin organization are infertile. Now, scientists show that treating mice with a drug known to inhibit that protein impedes sperm development and renders the animals infertile—but halting treatment allows sperm production to restart and mice to sire normal litters.

The results, published in Cell, suggest that targeting this protein could produce a safe, reversible method for non-hormonal male contraception—a long-sought goal that has so far failed to materialize as an option alongside condoms and vasectomies.

Hormonal male contraception methods are already well-established. Male hormonal contraception works at least as well as a typical female oral contraceptive pill. But such contraceptives still have some significant hurdles to overcome before making it to market.

First, the strategy, which involves administering a hormone (usually a progestin) to halt production of testosterone and thus inhibit sperm development, does not suppress sperm production enough in every man. It also requires dosing with enough exogenous testosterone to maintain libido and muscle mass, but there’s currently no cheap and easily applied testosterone on the market. Furthermore, hormone-based male contraception can cause side effects. Unlike side effects for the female hormonal contraception, these can’t be balanced against the risks of pregnancy, which are often higher, noted John Amory at the University of Washington. Because men don’t run the same medical risks of pregnancy, there’s a higher bar for ensuring that contraception administered to healthy men doesn’t carry risks. Finally, despite worldwide surveys suggesting public receptiveness to a male contraceptive pill, pharmaceutical companies no longer fund development of such drugs.

Some of these issues have spurred researchers to look for a non-hormonal way to temporarily induce infertility in men, which should cause with fewer side effects and be more appealing to pharma. Amory’s work, for example, has shown that a compound that targets the retinoic acid pathway of sperm development reversibly inhibits sperm production. The drug’s potential is hamstrung by the fact that men taking the drug can’t consume alcohol without nausea—a side effect he’s currently working to circumvent.

The current study builds on previous work by Debra Wolgemuth at Columbia University showing that BRDT—a testes-specific member of a family of bromodomain-containing proteins, which are important for regulating chromatin organization in various tissues—was critical for normal sperm development in mice. Truncating BRDT has an amazing effect on haploid sperm development. Removing the first bromodomain results in production of a shortened protein and, consequently, the aberrant organization and packaging of DNA in the sperm cells produced. Spermatids fail to elongate normally in mutant mice, resulting in decreased sperm production, misshapen sperm, and infertility.

In order to test the possibility that a BRDT-inhibiting drug, JQ1, might have potential as a male contraceptive, Martin Matzuk of Baylor College of Medicine and his collaborators injected male mice daily with the drug, and examined their testis volume. This volume, which reflects the amount of sperm in the testes, dropped by 60 percent over the 6 weeks of treatment. The sperm count of these mice was nearly 90 percent lower than in control mice, and sperm motility also plunged in JQ1-treated mice, collectively resulting in infertility. Though JQ1 is known to inhibit related proteins expressed elsewhere in the body, the mice seemed to have no other effects from JQ1 treatment, and normal hormone levels in treated mice suggested that infertility wasn’t the result of a hormone imbalance.

A closer look at sperm generation in JQ1-treated mice suggested that sperm development was primarily blocked after the sperm cells had undergone meiosis, but before they began the process of elongating—a similar stage to that seen in BRDT-mutant mice. Importantly, the mice regained the ability to sire pups after several weeks off the drug.

The reversibility of the treatment is likely attributable to the fact that the researchers are targeting sperm cells midway through development, rather than accessory cells that support sperm development from stem cells, noted Michael Griswold, who studies sperm cell development at Washington State University, but did not participate in the study. It’s “a great place to inhibit, because you don’t get sperm cells, but you don’t affect stem cells, which makes [the treatment] reversible,” he explained.

Whether JQ1 acts by primarily targeting BRDT and derailing chromatin organization or whether it inhibits other family members expressed during sperm development remains unclear. Matzuk and his colleagues examined gene expression in JQ1-treated and control mice, and saw decreased expression of many genes important for meiosis, suggesting that JQ1 may be working by affecting transcription of a suite of important genes for spermatogensis. Also, because JQ1 also inhibits BRDT-related proteins, researchers need to be watchful for long-term side effects not detected in the current study, Matzuk noted. Going forward, it will be important to design drugs that selectively target BDRT.

Source References:

 

http://www.ncbi.nlm.nih.gov/pubmed?term=Small-molecule%20inhibition%20of%20BRDT%20for%20male%20contraception

http://the-scientist.com/2012/08/16/hope-for-male-contraception/?goback=%2Egde_3695897_member_148573151

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Reported by: Dr. Venkat S Karra, Ph.D.

Two-thirds of Americans aged 15 to 24 have engaged in oral sex, according to a broad new survey of young people’s sexual habits.

The data, published Aug. 16 in the U.S. Centers for Disease Control and Prevention’s National Health Statistics Reports, also reveals that about one-quarter of young people try oral sex before they engage in intercourse.

“I don’t think these numbers are surprising, but I do think that it’s important that this data has been captured at all, because it’s really important to have, and has for a long time been a fuzzy area in our understanding of sexual behavior,” said one expert, Dr. Christopher Hurt, A clinical assistant professor in the division of infectious disease at the University of North Carolina.

He said the findings are also valuable because too many people of all ages mistakenly believe that oral sex is “risk-free.”

“That’s not the case,” Hurt said. “Studies looking, for example, at patients visiting STD [sexually transmitted disease] clinics have shown that 5 to 10 percent have gonorrhea in the throat. And it’s often asymptomatic and can be transmitted through oral sex.”

Gonorrhea is becoming increasingly resistant to antibiotics, and a report released last week by the CDC noted that certain strains are resistant to all but one such drug. Oral sex can also raise risks for infection with chlamydia, herpes and syphilis, the CDC noted.

Oral sex is also increasingly linked to transmission of the human papillomavirus (HPV), which may be linked to cancers of the throat and oral cavity, in addition to cervical cancer, experts say.

While the odds of contracting any sexually transmitted disease from oral sex remain lower than that for unprotected intercourse, the CDC has stated that “numerous studies have demonstrated that oral sex can result in the transmission of HIV and other sexually transmitted diseases.”

The new report is based on data from the agency’s seventh National Survey of Family Growth, involving interviews conducted between 2007 and 2010 with nearly 22,700 people between the ages of 15 and 44.

Even though the survey found that about one-quarter of Americans aged 15 to 24 engaged in oral sex before they moved on to intercourse, for about another quarter of respondents the opposite was true — they tried penile-vaginal intercourse prior to engaging in oral sex. Among males, 12 percent said their first experience with both practices occurred at the same time, while a little more than 7 percent of women said that that was the case for them.

Examining behaviors solely among the youngest participants — those 15 to 19 years old — the CDC team found that more than half of American girls and boys in this age group had already engaged in some form of sexual contact with someone of the opposite sex (55 percent of girls and 58 percent of boys).

Among the survey’s other findings:

  • About 5 percent of women and nearly 7 percent of men aged 15 to 24 said that at the time of the survey they had only engaged in oral sex, not intercourse. Another 28 percent of women and nearly 29 percent of men said they had had no sexual experiences with an opposite-sex partner whatsoever.
  • Among girls aged 15 to 19 years, oral sex and vaginal intercourse experience were equally common (48 percent and 47 percent, respectively), while among similarly aged boys oral sex was slightly more common (49 percent) compared to intercourse (44 percent).
  • Rates of sexual behaviors did not appear to vary widely by race. For example, among females aged 15 to 24, nearly three-quarters (74 percent) of black women, 68 percent of Hispanic women and 66 percent of white women said they had had vaginal intercourse.
  • Among males aged 15 to 24, about seven in 10 black and Hispanic men said they had had intercourse, compared with 63 percent of white men. There were no appreciable racial differences observed in terms of the percentages of those who said they had engaged in oral sex, the CDC survey found.

According to Hurt, young people need to be properly armed with knowledge before they engage in their first sexual activity, and that includes information on the risks that accompany oral sex.

“I would say that the risk of STD transmission through oral sex is underappreciated and underestimated,” he said. “As part of sex education programs, kids need to be made aware of that fact: that oral sex is not a completely risk-free activity.”

SOURCES: Christopher Hurt, M.D., clinical assistant professor, division of infectious diseases, University of North Carolina, Chapel Hill; Aug. 16, 2012, U.S. Centers for Disease Control and Prevention’s National Center for Health Statistics report, Prevalence and Timing of Oral Sex with Opposite-Sex Partners Among Females and Males Aged 15-24 Years: United States: 2007-2010

Source

http://www.nlm.nih.gov/medlineplus/news/fullstory_128320.html

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Cumulative Birth Rates with Linked Assisted Reproductive Technology Cycles

 

Reporter: Aviva Lev-Ari, PhD, RN

 

Barbara Luke, Sc.D., M.P.H., Morton B. Brown, Ph.D., Ethan Wantman, M.B.A., Avi Lederman, B.A., William Gibbons, M.D., Glenn L. Schattman, M.D., Rogerio A. Lobo, M.D., Richard E. Leach, M.D., and Judy E. Stern, Ph.D.

N Engl J Med 2012; 366:2483-2491   June 28, 2012

BACKGROUND

Live-birth rates after treatment with assisted reproductive technology have traditionally been reported on a per-cycle basis. For women receiving continued treatment, cumulative success rates are a more important measure.

METHODS

We linked data from cycles of assisted reproductive technology in the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database for the period from 2004 through 2009 to individual women in order to estimate cumulative live-birth rates. Conservative estimates assumed that women who did not return for treatment would not have a live birth; optimal estimates assumed that these women would have live-birth rates similar to those for women continuing treatment.

RESULTS

The data were from 246,740 women, with 471,208 cycles and 140,859 live births. Live-birth rates declined with increasing maternal age and increasing cycle number with autologous, but not donor, oocytes. By the third cycle, the conservative and optimal estimates of live-birth rates with autologous oocytes had declined from 63.3% and 74.6%, respectively, for women younger than 31 years of age to 18.6% and 27.8% for those 41 or 42 years of age and to 6.6% and 11.3% for those 43 years of age or older. When donor oocytes were used, the rates were higher than 60% and 80%, respectively, for all ages. Rates were higher with blastocyst embryos (day of transfer, 5 or 6) than with cleavage embryos (day of transfer, 2 or 3). At the third cycle, the conservative and optimal estimates of cumulative live-birth rates were, respectively, 42.7% and 65.3% for transfer of cleavage embryos and 52.4% and 80.7% for transfer of blastocyst embryos when fresh autologous oocytes were used.

CONCLUSIONS

Our results indicate that live-birth rates approaching natural fecundity can be achieved by means of assisted reproductive technology when there are favorable patient and embryo characteristics. Live-birth rates among older women are lower than those among younger women when autologous oocytes are used but are similar to the rates among young women when donor oocytes are used. (Funded by the National Institutes of Health and the Society for Assisted Reproductive Technology.)

The views expressed in this article are those of the authors and do not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health.

Supported by the National Cancer Institute, National Institutes of Health (grant R01 CA151973), and the Society for Assisted Reproductive Technology (SART).

Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.

We thank all the members of SART for providing clinical information to the SART Clinic Outcome Reporting System database for use by patients and researchers.

SOURCE INFORMATION

From the Departments of Obstetrics, Gynecology, and Reproductive Biology (B.L., R.E.L.), Michigan State University, East Lansing; the Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor (M.B.B.); and the Department of Obstetrics, Gynecology, and Women’s Health, Spectrum Health Medical Group, Grand Rapids (R.E.L.) — all in Michigan; Redshift Technologies (E.W., A.L.), the Department of Obstetrics and Gynecology, Cornell Medical Center (G.L.S.), and the Department of Obstetrics and Gynecology, Columbia University Medical Center (R.A.L.) — all in New York; the Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston (W.G.); and the Department of Obstetrics and Gynecology, Dartmouth–Hitchcock Medical Center, Geisel School of Medicine at Dartmouth, Lebanon, NH (J.E.S.).

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SAME SCIENTIFIC IMPACT: Scientific Publishing – Open Journals vs. Subscription-based

Reporters: Aviva Lev-Ari, PhD, RN & Pnina G. Abir-Am, PhD

Drastic change in academic education by design: FREE ACCESS to knowledge — Program edX – the  Harvard+MIT collaboration on Online education!! 
FREE ACCESS to Scientific Journals will be the next step. Research to support that by a study carried by Bjork, B. C., and D. Solomon. 2012. Open access versus subscription journals: a comparison of scientific impact. BMC Medicine. 10(1):73+. 
“Following step will be to demonstrated that Scientific Websites like http://pharmaceuticalintelligence.com have SAME Scientific impact as Open Journals!!
“We are well positioned to demonstrate that” said Aviva Lev-Ari, PhD, RN, Director & Founder of Leaders in Pharmaceutical Business Intelligence and the 2/2012 launcher of the initiative called  http://pharmaceuticalintelligence.com  To trace her contributions to Research Methodology, 1976-2005, go to  https://sites.google.com/site/avivasopusmagnum/aviva-s-home-page
The merit of Scientific Website is manifold:
  • Time from Lab/Desk to Publication on the Internet and Search engines is reduced to seconds
  • comments by other scientists are equally valuable to peer review
  • collaboration with other scientist around the globe is fostered on WWW
  • the platform is of collaborative authoring, we have 60 categories of research in one site
  • interdisciplinary work can be published in one site the over arching domain in our case is Life Sciences, Pharmaceutical and Healthcare
In May 2012 MIT and Harvard are collaborating on distribution of course material of all classes on the Internet – a Program called EdX
In the Press Release“EdX represents a unique opportunity to improve education on our own campuses through online learning, while simultaneously creating a bold new educational path for millions of learners worldwide,” MIT President Susan Hockfield said.

Harvard President Drew Faust said, “edX gives Harvard and MIT an unprecedented opportunity to dramatically extend our collective reach by conducting groundbreaking research into effective education and by extending online access to quality higher education.”

“Harvard and MIT will use these new technologies and the research they will make possible to lead the direction of online learning in a way that benefits our students, our peers, and people across the nation and the globe,” Faust continued.

Princeton, Stanford, Michigan and the University of Pennsylvania announced that they would offer free Web-based courses through a for-profit company called Coursera that was founded by two Stanford computer science professors. One of those professors, Andrew Ng, taught a free online course in machine learning this past fall with an enrollment of more than 100,000 students.

There’s also Udacity, co-founded by a former Stanford professor, andKhan Academy, which boasts 3,100 free educational videos across a variety of subjects.

MIT and Harvard said that they hope to eventually partner with other universities to expand the offerings on the edX platform.

Results of the BMC Medicine study are reported, below and they are:  Open Access, But Same Impact
profile

BioTechniques

http://www.biotechniques.com/news/Open-Access-But-Same-Impact/biotechniques-333012.html#.UA2SsRxueMU 

Open Access, But Same Impact

07/19/2012

Jesse Jenkins
By comparing two-year impact factors for journals, researchers found that open access and subscription-based journals have about the same scientific impact.
Open access (OA) journals are approaching the same scientific impact and quality as traditional subscription journals, according to a new study. In a study published in BMC Medicine on July 17 (1), researchers surveyed the impact factors, the average number of citations per paper published in a journal during the two preceding years, of OA and traditional subscription journals.

By comparing two-year impact factors for journals from the four countries that publish the most scientific literature, researchers have found that OA journals have about the same scientific impact as their subscription-based counterparts. Source: BMC Medicine.

At first, the study’s authors—Bo-Christer Björk from the Hanken School of Economics in Helsinki, Finland, and David Solomon from the College of Human Medicine at Michigan State University—found that there was a 30% higher average citation rate for subscription journals. But after controlling for journal discipline, location of publisher, and age of publication, their results showed that OA and subscription journals had nearly identical scientific impact.

“The newer open access published within the last 10 years, particularly those journals funded by article processing fees, had basically the same impact as subscription journals within the same category,” said Solomon. “I think that that is the key finding.”

The initial higher citation rate for subscription journals was the result of a higher percentage of older OA journals from countries that are not major publishing countries. “A lot of them are from South America or other developing countries, and they tend to have lower impact factors,” said Solomon. “When you compare apples to apples and start looking within subgroups, particularly journals launched after 2000 in biomedicine for example, the differences fall away.”

However, the authors identified a sector of low quality, OA publishers that are looking to capitalize on the article processing charge model rather than contribute to the advancement of science. Solomon said that this could partly be to blame for negative perceptions about the integrity of OA publishing as a whole and its impact on the peer review system. But most researchers are aware of these low-quality publishers and prefer to publish in more reputable OA journals.

In the end, Bjork and Solomon are hopeful that the study’s findings may help dispel some of the misconceptions in the debate over OA publishing. “Open access journals still have the reputation of being second class in the minds of some people. So, we think that this is important because this is objective data verifying that at least the open access journals published in the last 10 years by professional publishers are on par with subscription journals.”

References

  1. Bjork, B. C., and D. Solomon. 2012. Open access versus subscription journals: a comparison of scientific impact. BMC Medicine. 10(1):73+.

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Reporter: Sudipta Saha, Ph.D.

Laboratory testing is an integral component of the evaluation of the infertile men. This testing must be appropriate and specific for the individual couple. As there are many tests that evaluate various aspects of infertility, the urologist have to decide what information the tests can offer as well as the limitations of each assay. The semen analysis remains the cornerstone of the evaluation but is not a functional assay. Other assays such as sperm-cervical mucus tests, hemizona assays, and the sperm-penetration assay are functional tests. Through the appropriate use of these and other tests, the urologist will be capable of better and more accurately counseling the infertile couple (http://www.springerlink.com/content/t518435632851834/).

5.3 million American couples of reproductive age (9%) are affected by infertility, among which male factors account for up to 50% of cases, which necessitates the identification of parameters defining sperm quality, including sperm count and motility. In vitro fertilization (IVF) with or without intra cytoplasmic sperm injection (ICSI) has become the most widely used assisted reproductive technology (ART) in modern clinical practice to overcome male infertility challenges. One of the obstacles of IVF and ICSI lies in identifying and isolating the most motile and presumably healthiest sperm from semen samples that have low sperm counts (oligozoospermia) and/or low sperm motility (oligospermaesthenia). Microfluidic systems have shown potential to sort sperm with flow systems. However, the small field of view (FOV) of conventional microscopes commonly used to image sperm motion presents challenges in tracking a large number of sperm cells simultaneously. To address this challenge, Zhang et. al. at Harvard Medical School and MIT integrated a lensless charge-coupled device (CCD) with a microfluidic chip to enable wide FOV and automatic recording as the sperm move inside a microfluidic channel. The integrated system enables the sorting and tracking of a population of sperm that have been placed in a microfluidic channel. This channel can be monitored in both horizontal and vertical configuration similar to a swim up column method used clinically. Sperm motilities can be quantified by tracing the shadow paths for individual sperm. Moreover, as the sperm are sorted by swimming from the inlet towards the outlet of a microfluidic channel, motile sperm that reach the outlet can be extracted from the channel at the end of the process. This technology can lead to methods to evaluate each sperm individually in terms of motility response in a wide field of view, which could prove especially useful, when working with oligozoospermic or oligospermaesthenic samples, in which the most motile sperm need to be isolated from a pool of small number of sperm (http://mit.edu/bammlabs/Lensless_Imaging.pdf).

There are also some new kit based methods developed to analyze male fertility at home. There is no need to count hundreds of sperm in these methods. They are user-friendly, quite affordable (between 40 and 100 dollars) and quick. One of the pioneers on the market is FertilMARQ Home Diagnostic Screening Test, which works by staining the cells in the sperm sample to produce a color. The intensity of this color is then compared to a color reference on the FertilMARQ test cassette providing results with an overall accuracy of 78 percent. Another popular home kit is Spermcheck fertility, known to be 97 percent accurate. This test is based on the detection of SP-10, a protein compound found on the surface of the head of a sperm cell and which concentrations are directly related to the sperm count number (http://howto.wired.com/wiki/Check_a_Man’s_Sperm_Count).

Techniques such as Vasectomy Reversal and Tubal Ligation Reversal, In vitro fertilization (IVF), Intra-cytoplasmic sperm injection (ICSI) have also improved with respect to the instrumentation used. Dr. Sherman J. Silber, M.D. and his Japanese collaborators have recently developed a new “mini-IVF” technique that saves money, eliminates complications of IVF, and is useful for older women and women with low ovarian reserve. (http://www.infertile.com/).

The pioneer company in making the most sophisticated and most popular sperm analysis instrument is Hamilton Thorne (http://www.hamiltonthorne.com/products/casa/systems-index.htm) and their website may be reviewed for more knowledge on modern sperm analysis.

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