- Zika Virus Reduces Male Fertility in Mice
- Opioid Poisoning in Toddlers Increases 205%
- Male Birth Control Shots are 96% Effective, Study Finds
Posted: 31 Oct 2016 09:00 AM PDT
The Zika virus is known to influence developing fetuses and pregnant women, and now researchers are turning their attention to the possible effects on men. There is growing evidence that Zika can be sexually transmitted from an infected man to another partner, and studies show that the virus can remain in semen and sperm for months. Does the virus have long-term effects on the male reproductive tract and on male fertility?
Dr. Michael Diamond, professor of medicine, molecular microbiology, pathology and immunology at Washington University School of Medicine in St. Louis, and his team explored that question in mice. In a paper published in Nature, they report on how Zika affected the reproductive health of male mice, and the findings suggest more extensive damage to fertility than previously thought.
Diamond conducted extensive studies of the reproductive organs of male mice and found the virus damaged key sperm-making organs, as well as the stem cells that sire the sperm in a male. The testes in infected mice were also smaller compared to those in uninfected animals. Zika’s effect on male mice is two-fold, he says: first on the architecture, including the early sperm cells and the Sertoli cells in the testes, as well as the seminiferous tubules, which serve as the conveyer belt through which immature sperm cells pass as they receive the proper hormones to develop and mature. The virus also affects the sperm stem cells, which are the grandfather cells that produce all sperm. In essence, Zika hampers the sperm-making process by producing fewer sperm, as well as interfering with the development of the few sperm that do get released.
“In mice, the damage caused by Zika leads to not just loss of architecture but decreases in sperm count, loss of hormones and ultimately decreased fertility,” says Diamond. When the Zika-infected male mice mated, they were less likely to sire pups than uninfected males.
Whether similar damage is occurring in the testes of men infected with Zika isn’t clear yet. But the results do raise concern for the need to study men as well as women and babies infected with the virus. “These results suggest that if the same [effects] happen in men, we may need to be treating men much more aggressively than we probably thought,” he says. Up until now, the management of Zika in men focused mostly on preventing transmission of the virus. But it’s possible, says Diamond, that “if it turns out that Zika is causing more damage [to male reproduction], then we need to be more aggressive about treatment in men not just to interrupt sexual transmission but to prevent damage to their reproductive organs.”
Much more research is also needed to better understand how Zika affects male fertility. For one, related viruses like West Nile or dengue do not seem to cause the same damage to the testes in the mice that Diamond tested as Zika. His group is collaborating with researchers in South and Central America, where Zika is endemic, to start investigating how the infection affects male fertility. The scientists are planning to track things like sperm count, motility and testosterone levels to see if the changes they found in mice are also occurring in men.
Posted: 31 Oct 2016 08:00 AM PDT
The toll opiates are taking on the U.S. population is growing uncomfortably familiar, and causing enough harm that opioid abuse has prompted the Obama Administration to launch a campaign to address the problem and investigate ways to reverse the trend. While the opioid epidemic is certainly driven by illicit drugs such as heroin, the bigger problem is abuse of prescription opiates and the rampant over prescription of the addictive drugs for pain.
Given the ubiquity of prescription painkillers in U.S. households — the Centers for Disease Control predicts that 260 million prescriptions are written for the drugs every year, which is enough to put a bottle in nearly every home — Julie Gaither, a post doctoral fellow at Yale University School of Medicine, and her colleagues wanted to learn more about how young children are affected by the more easily accessible medications.
They studied 13,052 hospital records of children aged 1 to 19 years who were hospitalized for opioid poisoning between 1997 and 2012. During that time, the rate of opioid hospitalizations jumped 165% among children, with the largest spike among the youngest, a 205% increase for those aged one to four.
“We were surprised by the findings for the one to four year olds,” says Gaither, who published her findings in JAMA Pediatrics.
The surge suggests that children of all ages have more access to opioid drugs, which means that accidental ingestion and overdose are also more common. For older children in their teens, the rates of suicide attempts and attempts at self-harm remain higher than accidental poisonings, but the rate of accidental poisonings increased at a faster clip than that of suicides, indicating that the availability of the drugs may be leading to more accidental ingestion among older kids as well.
Among teens, the suicide and self-harm attempts remain the primary reason for opioid poisoning, suggesting that another problem might not be getting as much attention — that of depression and mental illness among young children. “Research shows that teens will self-medicate for depression with prescription opioids,” says Gaither.
The study also found disturbing evidence that as regulations make it harder to obtain prescription opiates, teens may be turning to heroin. Rates of hospitalizations for heroin have increased among adolescents aged 15 to 19 by 161%. Heroin is both cheaper than opioids and, in some cities, easier to purchase than a prescription opioid.
“What I hope is that people realize the opioid crisis affects everyone,” says Gaither. “Children make up a quarter of the U,S population, and we need to pay better attention to them when it comes to the opiates by limited their exposure to them.” For young children as well as teens, simply keeping the drugs out of reach can go a long way toward reducing poisoning, she says. “A lot of the solutions and interventions needed to address the opioid crisis are complex. But limiting exposure for children doesn’t have to be. We need to realize the opioid crisis is affecting us all, throughout the lifespan, from neonates through the elderly.”
Posted: 31 Oct 2016 06:43 AM PDT
Male birth control just got one step closer to becoming a reality (finally!). A new study shows that giving contraceptive injections to men can effectively prevent pregnancy in their partners. The caveat: the shots won’t be available any time soon. Their formulation must be tweaked to reduce side effects, and larger studies are needed before they can be brought to market.
Hormonal birth control has never been an option for men, who currently have few choices when it comes to managing their fertility, including condoms, vasectomies, and the not-always-effective withdrawal method.
The new study, a phase II clinical trial, tested the safety and efficacy of injectable contraceptives in 320 men ages 18 to 45. The men received two hormones—a synthetic testosterone and progesterone—via injection, every eight weeks for up to a year and a half.
Synthetic testosterone suppresses sperm count, explains Jamin Brahmbhatt, MD, a urologic surgeon with the Orlando Health hospital system, because it tricks the body into thinking it has enough of the hormone. The body then shuts down production of real testosterone, which is needed to make sperm.
“We already prescribe this drug to men who have low testosterone levels, and we warn our patients that they may experience infertility as a side effect,” Dr. Brahmbhatt, who was not involved in the new study, told Health. Pairing testosterone with the other drug tested in the study—a type of synthetic progesterone—has been shown to alleviate other side effects, he adds.
The participants provided semen samples regularly. Once their samples were shown to contain less than 1 million sperm per milliliter—which for most men, occurred within 24 weeks—they were instructed to stop using other forms of birth control with their partners (women ages 18 to 38) and rely only on the injections.
In the second phase of the study—during which 266 men continued receiving injections for up to 56 more weeks—four pregnancies occurred. (That makes sense, says Dr. Brahmbhatt, since a tiny amount of sperm is still likely to be present.) The researchers determined the drug combo was nearly 96% effective at suppressing sperm counts. Condoms, in comparison, are 98% effective when used correctly.
The results were published online and will appear in the Journal of Clinical Endocrinology & Metabolism. The research was funded by several global health organizations, including the United Nations and the World Health Organization (WHO).
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“The study found it is possible to have a hormonal contraceptive for men that reduces the risk of unplanned pregnancies in the partners of men who use it,” said co-author and WHO researcher Mario Philip Reyes Festin, MD, in a press release. “Our findings confirmed the efficacy of this contraceptive method previously seen in small studies.”
However, complaints from participants caused the researchers to stop enrolling new volunteers earlier than expected. The men reported side effects including muscle pain, pain at the injection site, increased libido, and acne. One participant was diagnosed with depression, one intentionally overdosed on acetaminophen, and one experienced an irregular heartbeat after he stopped receiving injections.
Overall, 20 participants dropped out of the study because of side effects. One person also died in a suicide, although researchers concluded that was not related to the drug. In fact, nearly 39% of the 1,491 adverse effects reported were found to be unrelated to the injections.
Despite the side effects, however, more than 75% of participants said they’d be willing to use this method of contraception once the trial was over.
They won’t have that option for at least a few years, though. “More research is needed to advance this concept to the point that it can be made widely available to men as a method of contraception,” Dr. Festin said. Along with larger, phase III trials, he added, “the combination of hormones needs to be studied more to consider a good balance between efficacy and safety.”
Dr. Brambhatt predicts it will be at least five to 10 years before a hormonal birth control method is approved by the Food and Drug Administration. When that does happen, however, he thinks injections will still be the delivery method (rather than a pill).
“With injections, the drug stays in your body,” he says. “You don’t have to think about it the way you do with condoms or even female birth control pills—which is one reason those methods sometimes fail. My patients who get injections for low testosterone really like that they don’t have to remember to take something every day.”
“Having a long-acting form of birth control for men will be ideal, and this is a step in the right direction,” he continues. “But this study doesn’t solve all of the problems we’ve seen so far, and we’re still far away from finding the right dosage.”
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