Tuesday, December 20, 2016

Do Women Make Better Physicians Than Men?

A new study published in JAMA Internal Medicine raises the very real possibility that in some undefined way, women may be better physicians than men. The authors of the study examined the records of more than a million and a half Medicare patients 65 and older admitted to a hospital, using 30-day mortality and readmission rates as their measured endpoints. They found that the 30-day death rate for patients treated by women physicians was lower than for patients treated by men physicians (11.07% vs. 11.49%). Patient readmission rates, too, were lower for women physicians. The differences were statistically significant and independent of medical condition or severity of illness.

To control for how patients were assigned to doctors, the authors focused on patients whose admissions were non-elective at hospitals and where the assignment of physician depended only on the physician's work schedule, and not on choice. Finally, to eliminate differences in physician specialty as a factor, the study focused only on physicians who were general internists.

The difference between 11.07% vs. 11.49% deaths would translate to four fewer deaths for every thousand patients treated by women physicians. Given that more than 10 million Medicare patients are admitted to hospitals every year, tens of thousands of lives might be saved if we could learn exactly how women physicians are different. One theory is that women physicians are more likely to stick to evidence-based protocols and medical practice guidelines, but that would need to be tested.

Thursday, December 15, 2016

A Full Recovery From Metastasized Colon Cancer

A woman with a type of colon cancer that had already metastasized to her lungs has now recovered, thanks to a new type of cancer therapy that relies on her own immune cells.  It may be too early to say that she is cured forever, but apparently she is now tumor-free.

The therapy relied on a type of immune cell called a tumor-infiltrating lymphocyte (TIL).  TILs are naturally occurring immune cells that recognize the specific genetic mutations in a tumor.  They attach to the tumor cells, attacking and killing them but leaving normal cells alone.  In most patients there aren't enough of these cells, though, to stop the cancer from growing.  In the specific patient case presented in the article, the researchers isolated some of these TIL cells from the woman's tumors, grew them in the laboratory, and then returned them (100 billion of them, in fact) to the patient, where they attacked and destroyed her tumors.

Researchers caution that this is the first and only time that this type of therapy has worked completely; a previous attempt in another patient had failed, probably because too few TILs were harvested.   However, a similar approach has been used to produce long periods of remission in 20-25% of patients with advanced melanoma, a particularly deadly form of skin cancer.  And similar experiments are underway with TILs found on other soft-tissue cancers such as pancreatic cancer.

With findings like this, we may yet see some cancers curable in our lifetimes.

Friday, December 9, 2016

Life expectancy declines in the U.S.

Life expectancy is defined as the number of years a person born in any given year can expect to live, on average.  It's commonly used to as a comparative measure of the health of a population over time, or to compare different populations.

In the past, life expectancy in the U.S. generally rose year-over-year as health care improved and the U.S. became more safety-conscious (the requirement that we use seat belts while driving, for example).  But now the Centers for Disease Control & Prevention (CDC) reports that life expectancy actually declined in 2015. A person born in 2015 can expect to live 78.8 years, on average - down from 78.9 years in 2014.

A decline of only 0.1 years doesn't sound like much, and indeed it isn't.  But life expectancy in the U.S. has risen steadily and consistently for over 45 years, so 2015 represents a noticeable change.  The only other year in those 45 years that life expectancy declined was 1993, at the height of the HIV/AIDS epidemic.

This time around, there doesn't seem to be just one obvious cause.  In 2015, eight of the ten top causes of death (including suicides and accidents, as well as chronic diseases such as heart disease and diabetes) showed an increase in death rates.  If life expectancy continues to decline in future years, health officials will have to dig deeper to try to discern the cause.  For now, a wait-and-see approach seems most appropriate.

Friday, December 2, 2016

AIDS "Patient Zero" Was Wrongly Accused

For many years, it was believed that the first outbreak of AIDS in the U.S. was triggered by just one person, dubbed "patient zero". That belief was popularized by Randy Shilts's best-selling book And The Band Played On, published in 1987. Patient zero was allegedly Gaetan Dugas, a French-Canadian flight attendant who was thought to have picked up H.I.V. in Haiti sometime in the late 1970s. Mr. Dugas died of AIDS in 1984. After his death Mr. Dugas was vilified by the media; a 1987 New York Post headline called him "The Man Who Gave Us AIDS".

The myth of "patient zero" persisted for almost 20 years. It wasn't until 2014 that careful detective work provided convincing evidence that HIV actually arrived in New York City around 1971 and was well established in the U.S. before Mr. Dugas became infected. And just recently, DNA analysis of a sample of Mr. Dugas's stored blood confirmed that he was not the infamous "patient zero", if indeed there ever was one.

Mr. Dugas was not the villain he was made out to be, despite the fact that he continued to be sexually active after he became infected. He deserves our belated apology.

Monday, November 28, 2016

Essure Contraception to Come With a Warning

Not mentioned in Human Biology: Concepts and Current Issues is a type permanent non-surgical contraception for women marketed by Bayer, called Essure.  Essure consists of a pair of small coiled devices placed in the two fallopian tubes through the vagina.  The devices trigger local inflammatory responses that seal off the fallopian tubes within about 3 months, rendering the woman permanently sterile.  When it was first approved in 2002, Essure became the first permanent sterilization procedure that could be done in a doctor's office without general anesthesia or a surgical incision, making it an attractive option to surgical tubal ligation for some women.

Now it appears that Essure will come with an FDA-mandated warning that it may cause unwanted effects in some women, including possible puncture of the fallopian tubes or uterus and intense pain.  The FDA is not requiring that the devices be pulled from the market at this time because the device has been proven safe and effective for most women.  However, the FDA did work with Bayer to develop a 3-page checklist that physicians and patients may find useful in evaluating the risks and benefits of Essure versus surgical tubal ligation.

Bayer, of course, blames any problems associated with Essure on poor skills on the part of doctors implanting the devices.  There could be some truth to that. For most medical procedures, physicians who have done a lot of them tend to have fewer reported complications.  It's always wise to choose your physician carefully.

Tuesday, November 15, 2016

Vice-President-Elect Mike Pence Says "Smoking Doesn't Kill"

The U.S. will soon have a Vice-President who denies the health dangers of smoking cigarettes. The Former Indiana governor and U.S Congressman has consistently argued that there is no causal link between smoking and lung cancer. In 2000 he wrote, "Time for a quick reality check. Despite the hysteria from the political class and the media, smoking doesn't kill." He has yet to change his position.

The Surgeon General of the United States clearly identified the risks associated with smoking in a report released back in 1964. Since then, nearly all states have set up smoking cessation programs. Mike Pence cut funding for Indiana's smoking cessation program when he was Indiana's governor while receiving generous campaign contributions from the tobacco industry, according to a ThinkProgress investigative report.

You can't dismiss away overwhelming scientific evidence just because it isn't politically expedient. Smoking does kill, Mr. Vice-President-Elect.

Friday, November 11, 2016

Medical Abortions Without Visiting an Abortion Clinic

A study is underway in four states (Hawaii, Washington, Oregon, and New York) to determine whether medical abortions can be conducted safely without the woman ever having to visit an abortion clinic.

Currently, women must visit to an abortion clinic for a medical abortion.  After consultation with a physician, the woman is prescribed two pills; the first is given at the abortion clinic, and the second is taken a day later.  Together, the two pills cause a miscarriage.  Medical abortions are FDA-approved during the first 10 weeks of pregnancy; after that, only surgical abortions are allowed.   Nearly a quarter of all abortions in the U.S. are now medical abortions.

In the current study, women will first consult with an abortion provider by video, from the comfort of her own home.  Then certain tests must be completed, including blood work and an ultrasound.  If all goes well, the medical abortion pills will be delivered by mail.

The FDA has approved the study and will be monitoring the safety of the procedure closely.  But pro-life advocates are unlikely to favor FDA approval of medical abortions by videoconference and mail, regardless of how safe it turns out to be.

Monday, November 7, 2016

An Increase in Suicides Among Young Adolescents

From 2007 to 2014 (the last year for which data are available) the suicide rate among young adolescents aged 10 to 14 doubled, according to the Centers for Disease Control and Prevention (CDC). In 2014 there were 425 deaths from suicide in this age group. And for the first time, the number of deaths by suicide among young adolescents exceeded the number of deaths from auto accidents, which has been declining in recent years.

The trend is disturbing, but for now a cause (or causes) has not been identified. Officials speculate that one factor may be the rise of social networking, which enables bullying to be witnessed not just by a close group of friends or classmates, but the whole school and even the wider community, magnifying the shame and unhappiness of the victim. And with 24-hour access to the social networking, bullying does not necessarily end after school.

It's something to think about. Is there anything we might do to reverse this trend?

Thursday, November 3, 2016

Bioengineered Tobacco Plants Produce an Antimalarial Drug

One of the main weapons against malaria, a drug called artemisinin, comes from a plant called sweet wormwood. Unfortunately sweet wormwood grows slowly and the yield of artemisinin per plant is low. In addition, extraction of the drug is difficult and expensive. As a result, the supply of purified artemisinin is currently insufficient to meet worldwide demand.

That's where genetic engineering may come to the rescue. Researchers have managed to insert 12 key genes in the artemisinin biosynthetic pathway into tobacco plants. The modified tobacco plants grow quickly and produce much more artemisinin per gram of dried leaf than sweet wormwood. Indeed, they produce so much artemisinin that just feeding the dried leaves directly to malaria-infected mice works as well against malaria as administering purified artemisinin. The researchers suggest that by creating genetically modified plants that produce high concentrations of artemisinin, extraction and purification of the drug may not be necessary at all.

No one is suggesting that it would be a good idea to feed malaria-infected kids a steady diet of dried tobacco leaves. But as a proof of concept, these new findings demonstrate that it might be possible to genetically engineer another plant to produce artemisinin. Perhaps some day the drug will be produced in an edible plant, such as beets or lettuce.

Wednesday, October 26, 2016

Dishonesty May Be a Slippery Slope

Why is it that some people seem to lie or cheat consistently, with no apparent remorse? According to a report in Nature Neuroscience, it may be that they have been lying (or cheating) for so long that their brains' neural circuits have adapted to it, leaving them insensitive to their own dishonesty.

The researchers devised a research protocol in which volunteer subjects were put in a situation in which deliberate dishonesty was to their advantage, with no risk of detection. (As controls, other subjects were put in a situation in which only honesty was to their advantage.) Using magnetic resonance imaging (MRI), the researchers found that subjects who were dishonest showed a reduction in brain activity in the amygdala, the area of the brain associated with emotions. The degree of reduction of activity in the amygdala tracked with the history of dishonesty, suggesting adaptation. Even more startling was the finding that the rate of amygdala adaptation predicted the rate of escalation of subsequent dishonesty. It appears, then that dishonesty tends to increase with repetition.

Nearly everyone tells a little lie now and then ("That dress looks great on you!"). But when lying becomes a self-serving habit, it may become a habit that's hard to break. Think about that the next time you are tempted to cheat on an exam.

Tuesday, October 25, 2016

New Infant Safe-Sleep Recommendations to Prevent SIDS

Every year in the U.S., approximately 3,500 seemingly healthy infants die suddenly during their sleep.  A few deaths are clearly due to strangulation or suffocation, but most are lumped under the ill-defined heading of sudden infant death syndrome (SIDS).  The actual causes of many of these SIDS deaths are never identified clearly, though it is suspected that certain body positions and the type of bedding may contribute to many of the cases.  The highest risk is to infants between 1 and 4 months of age.

Recognizing that parenting is a new and potentially overwhelming experience for some parents, the American Academy of Pediatrics (AAP) has produced relatively easy-to-understand guidelines for parents that are designed to reduce the risk of SIDS.  Foremost among them; newborns should sleep in a crib or bassinet in the same room as their parents for at least six months, and preferably up to a year.  According to the AAP, room-sharing alone reduces the risk of SIDS by 50%.  The crib (or bassinet) should have a relatively firm, bare sleep surface that is free of toys, pillows, and, if possible, even blankets.  The newborn should be placed on his/her back.  If blankets are necessary for warmth, they should not restrict the baby's breathing or cause overheating.

For some reason, breastfeeding also apparently reduces the risk of SIDS, so it, too, is recommended. And it goes without saying that the infant should not be exposed to smoke, alcohol, or illicit drugs.

Simple, really.  Easy enough for even a new parent to understand, and that's the point. A little prevention goes a long way.

Thursday, October 13, 2016

Why is Myopia on the Rise?

Babies are born with "short" eyeballs, so shortly after birth they are unable to focus on near objects. During early childhood the eyeball elongates until both near and far images are in proper focus. At that point, eyeball elongation generally stops. However, in some people the eyeball continues to elongate beyond its ideal length. The result is the common condition known as myopia, in which the person now sees distant objects as fuzzy and out of focus. Fortunately, the condition is easily corrected with corrective lenses or Lasix surgery.

The incidence of myopia has doubled among young U.S. adults in the past 50 years. No one knows for sure why, though there are some interesting theories. One is that we spend too much time on our computers, cell phones, video games, etc., looking at screens up-close. Another theory is that we don't spend enough time outside in the sunlight. The second theory is supported by research in animals showing that a neurotransmitter called dopamine controls elongation of the eye; too little dopamine throughout childhood and young adulthood allows elongation to continue, leading to myopia. And, as it turns out, dopamine production is stimulated by sunlight.

The theory that the rise in incidence of myopia might be due to too little time in the sun is interesting, but no one is suggesting just yet that spend more time outside. For starters, we don' have any idea just how much time in the sun might be needed to prevent myopia. And we wouldn't necessarily want to trade myopia for skin cancer when myopia is so easily corrected.

Friday, October 7, 2016

Is There a Natural Limit to Human's Lifespan?

For at least a century, human life expectancy (how long a person can expect to live) has been steadily increasing. Some of the increase in life expectancy has been due to advances in medicine and improvements in health care delivery. An increased awareness of safety has also had an effect. And yet, we can all expect to die sometime. Is there a natural upper limit to the human lifespan?

Better understanding of the process whereby cells age and die has led some scientists to propose that the aging process could someday be slowed, to the extent that humans could live a lot longer than they currently do. That may be possible in the distant future. But a new report in Nature seems to suggest that in the absence of successful intervention with the aging process, the "natural" limit to the human lifespan is about 115 years.

The evidence is intriguing. Using the death records of the International Database on Longevity, the authors plotted the age of the oldest person to die in each year from 1968 to 2006. The age of the oldest person to die in any given year rose from 111 years old in 1969 to about to 115 years old in 1995. But since that time it has risen no further. Only three persons have ever lived longer than 115 years (call them exceptions). So unless those scientists who are working on delaying the aging process achieve a breakthrough soon, you better plan on having your affairs in order by the time you reach 115 years old.

Sunday, October 2, 2016

Health Impact of Air Pollution

The World Health Organization (WHO) has just released its latest figures for air pollution worldwide. According to WHO, one specific type of air pollution is associated with over 3 million deaths per year worldwide, not to mention the adverse health effects it produces. It's not ozone or other gaseous pollutants; it's PM 2.5 (particulate matter smaller than 2.5 micrometers in diameter). PM 2.5 is especially damaging to the lungs because it is small enough to be drawn into the deepest parts of the lung's airways. In industrial areas, PM 2.5 includes byproducts of diesel fuel combustion and black carbon, a component of soot. In rural areas and in some cities, naturally-occurring dust is a major contributor.

It might surprise you to learn that the highest levels of air-borne particulate matter worldwide are not necessarily in the most industrialized countries. According to the WHO, the highest levels of PM 2.5 are found in Northern Africa, the middle East, India, and parts of Asia. That's because in many of these areas, naturally-occurring dust is a major problem. In the United States, though, the most significant air pollutants are man-made. Major U.S. cities with the worst air are Chicago and Los Angeles; the states with the worst air are Illinois, Indiana and Ohio, in the industrial heartland. You can use WHO's interactive map to find the reported levels of particulate matter in your specific area. The full WHO report can be viewed here.

Admittedly, we're not likely to make much headway against the problem of naturally-occurring dust anytime soon. Nevertheless, adequate monitoring and reporting can at least warn citizens when their air quality is at its worst, and better education can help them take precautions. Man-made pollution is another matter; in addition to monitoring and education, progress can (and should) be made to reduce its occurrence, to the extent it is feasible to do so.

We can pay now to reduce exposure to bad air or we can pay later in health care costs. It's our choice.

Wednesday, September 28, 2016

Cooler Fabrics

Staying warm indoors is easy; just put on a sweater, sweatshirt, or light jacket. But staying cool under warm conditions indoors has its limits. It's generally not socially acceptable to take off all clothing or even strip down to just a cotton t-shirt in a hot office. But soon there may be a solution. By taking advantage of knowledge of how the human body cools itself, researchers at Stanford University believe that they have developed a clothing fabric that can keep the wearer significantly cooler than other fabrics such as cotton. Their findings are documented in the Sept. 2 issue of Science and explained in layperson's terms in Forbes Magazine.

Except when a person is sweating, the body loses most of its heat as radiant heat energy in the infrared part of the wavelength spectrum. (You can't see infrared radiation because its wavelength is longer than visible light.) The problem is that fabrics such as cotton reflect most of this radiant heat back toward the body; that's partly how they keep the body warm. Understanding this, the researchers started with sheets of opaque polyethylene that allow 90% of IR radiation to pass through (cotton only transmits 5%.) Then they punctured it with tiny needles to allow air to pass through and added a substance that allows the fabric to wick moisture away. Finally, to make the material feel more like traditional fabrics they bonded two sheets of the material to a middle layer of widely spaced cotton mesh.

Then they tested the new fabric. In a room kept at 23.5oC the temperature of bare skin was 33.5oC, skin covered with cotton was 37oC, and skin covered with the new fabric was 35oC. That's fully 2oC lower than cotton, giving the new fabric an advantage in a warm room.

There's no guarantee that the new fabric will catch on with clothing designers. But at least it introduces a new way of thinking about how to create new fabrics for specific purposes, based on human physiology.

Thursday, September 22, 2016

Wearable Activity Monitors and Weight Loss

It may be fun to record how many steps you took today. But does wearing an activity monitor help a person to lose weight?

To find out, researchers at The University of Pittsburgh enlisted nearly 500 people in a randomized trial. For six months, all participants were asked to adhere to a low-calorie diet and to exercise in prescribed ways. After six months the diet and exercise recommendations were continued for another year and a half, but now half of the participants wore an activity monitor and the other half (the control group) did not.

The researchers had hypothesized that those wearing the activity monitors would lose more weight than those in the control group. Surprisingly, that was not the case. In fact, the activity monitor-wearers lost slightly less weight; only 7.7 lb versus 13.0 lb. in the control group.

So what are we to make of this? Not much, except that human beings and their behaviors are, well, complicated. Perhaps wearing an activity monitor reduces diet compliance (self-reported in this study). Or perhaps an activity monitor gives the wearer an inflated perception of how hard they actually are exercising, so that they aren't expending as many calories as they think (physical activity, too, was self-reported). Who knows? For now, all we know is that wearing an activity monitor doesn't help one lose weight.

Tuesday, September 20, 2016

Purposefully Causing the Extinction of a Species

Question: If it were technically possible, should we deliberately cause the extinction of species that we perceive as harmful (to us)? If we could actually eliminate forever the species of mosquitoes that carry certain human diseases such as yellow fever, malaria, and the Zika virus, should we do it?

Think hard on this question, because one day it may be possible. Right now, we know how to modify mosquitoes so that the males are sterile; when these sterile males are released into the wild there is a sharp drop in the mosquito population in the local region, but not a complete extinction because there are still plenty of wild normal males to ensure the survival of the species. But what if you could modify mosquito genes so that they could only produce male offspring? Such a change would wipe out the entire species in short order.

The ides of deliberately causing the extinction of certain species may be morally repugnant to some. But even if its not, we need to be aware of that there may be risks. Time and time again we've seen how the introduction of an invasive species disrupts an ecosystem. What might be the unintended consequence of the opposite scenario; eliminating a species from its ecosystem? If we were to eliminate a species in the wild, it might be wise to keep colonies of the species in captivity so that they could be re-introduced if necessary.

On the political front, who would be responsible for giving consent for a species extinction? Mosquitoes know no political boundaries. Any plan to eliminate a species, even one so universally unloved as a mosquito, should require nearly universal international approval. Don't count on that any time soon.

Wednesday, September 14, 2016

The Presidential Candidates' Plans to Reduce Drug Prices

What are Hillary Clinton's and Donald Trump's views on the skyrocketing costs of prescription drugs in the U.S.? Who, exactly, is to blame for the rising costs, and what could be done about it? There's an article in The Lancet (a British medical journal) last month on the subject. Some of Donald Trump's ideas are not well fleshed out, as is usual for Donald Trump: you just have to trust him. Hillary Clinton, also true to form, focuses her attention on specific changes that she has in mind.

After reading the article I was left with a lot of unanswered questions. For example, why is it that although the U.S. develops most of the drugs, we end up paying more for them than people in other countries? Should drug companies really get tax deductions for their marketing expenses? Why isn't Medicare allowed to negotiate drug prices directly with pharmaceutical companies, as insurance companies and pharmacy benefit management companies do?

There has been a lot of news coverage lately about Mylan Pharmaceuticals' epinephrine injection device called the EpiPen, which contains about a dollar's worth of epinephrine but sells for about $300. It's time to ask whether this is really reasonable.

Thursday, September 1, 2016

New Guidelines for Human/Animal Stem Cell Research

The National Institutes of Health (NIH) is considering updating its guidelines for stem cell research. The proposed new guidelines would allow human pluripotent stem cells to be inserted into non-human vertebrate embryos under certain conditions. Federal funding for such research has been prohibited since 2009 to give NIH time to study the issues carefully.

It seems clear that the NIH wishes to avoid the accidental (or on-purpose) production of human/animal chimeras; animals that are too close to human in their physical, mental, or emotional traits. To avoid this possibility, NIH plans to review carefully any experiments in which the human cells are introduced before the gastrula stage in the embryo - when the three germ cell layers begin to develop. A special restriction is that human cells may not be introduced into primates before the blastocyst stage. Proposals will be reviewed by a special steering committee comprised of scientists, ethicists, and even animal welfare specialists. The committee may consider such things as where the human cells are likely to end up in the animal, as well as how the human cells might affect the animal's physical and behavioral traits.

Why do this type of research at all? Scientists argue that the chimeras produced in this way (perhaps rodents with some human cells or tissue types) would be useful for understanding some human diseases, as well as for drug testing on animal models. Perhaps one day it might be possible to produce human organs suitable for transplant in animals. But that day is a long way off.

What do you think? You have until Sept. 6 to submit your comments NIH.

Caster Semenya Wins Gold at the Olympics

It has been a long and sometimes humiliating road for Caster Semenya, who won the women's 800-meter race at the 2016 Olympics. That's because Caster is thought to have an intersex condition characterized by ambiguous genitalia and quite possibly high testosterone levels - in other words, she may be a "tweener" in terms of gender. After she won the women's 800 meters race at the 2009 World Games, Caster was subjected to humiliating gender determination - by a committee, no less. Cleared to compete again in 2010, she won a silver medal in the 800 meters race at the 2012 Olympic Games (see this blog Aug. 16, 2012).

In an effort to establish a policy for female athletes that could be applied before competition, not after, in 2011 the International Association of Athletics Federations (IAAF) developed a policy based on testosterone levels. The first test case was a woman named Dutee Chand who was prevented from competing as a woman in 2014 because she had testosterone levels above the limit for females. Ms. Chand appealed the decision to the Court of Arbitration in Sport (CAS), based in Switzerland. In 2015 the CAS ruled in favor of Ms. Chand and suspended the IAAF's policy for two years. The CAS argued that there was insufficient evidence to conclude that women with high testosterone levels benefit from such a performance advantage that they should be excluded from competing as females. The court gave the IAAF two years to provide more persuasive evidence for its policy, if it could.

And that's where we stand today. Based on the CAS ruling, there was no way that a defensible policy defining femaleness for the purpose of athletic competition could have been developed for the 2016 Olympics, and so Caster Semenya was quietly allowed to compete again. In a brief statement, the International Olympic Committee said only that it encourages the IAAF to go back to the CAS "with arguments and evidence to support the reinstatement of it hyperandrogenism rules."

For the record, Caster Semenya has always identified herself as a woman. She wasn't looking for the controversy she caused in 2009, and she wasn't looking for it in 2016. She just wanted to compete. And that, after all, is the spirit of the Olympics.

Saturday, August 27, 2016

Sex Reassignment and Olympic Competition

For the 2016 Olympics, the International Olympics Committee (IOC) established a clear and defensible policy regarding persons who have chosen to undergo sex reassignment, so that they may compete in Olympic sports. The new policy recognizes that gender identity should be a personal choice; that all athletes should have the opportunity to compete in the Olympics; and that Olympics competition should be fair.

With these three guiding principles in mind, the IOC has set forth the guidelines for persons who transition from male to female. A transgender woman who wants to compete in the Olympics must have identified herself as a woman for at least the past four years. After that, she need only prove that her testosterone levels have been below 10 nmol/l for 12 months before her first competition and remain at those levels throughout her period of eligibility. Testing to verify these levels may be required. A testosterone level of 10 nmol/l is below the level found in normal males. (Presumably there would be no athletic advantage for a transgender person who had transitioned from female to male, so such persons may compete as males without restriction.)

Some might argue that having undergone development as a male until after puberty might confer a competitive advantage and thus be unfair to other female athletes. But barring male-to-female transgender athletes from the Olympics altogether would violate both the first and second principles; that gender identity is personal and that there be a way for all athletes to compete. Unless the new rules unleash a flood of male athletes transgendering to female just to compete in the Olympics (and no one expects that), the IOC has done the right thing. Good for them!

Friday, August 19, 2016

Did They Think the State was Kidding?

In July of 2015 the California legislature passed a law that requires all children to be vaccinated before they can attend school (see this blog, July 8, 2015). Unlike the previous law, the new law does not permit exceptions for either personal or religious beliefs. The new law will be phased in over seven years; this year and each subsequent year, all students entering kindergarten and the seventh grade will have to be vaccinated. (Current tenth- through twelfth-graders are exempt from the new law, as they'll all be out of school in three years anyway.)

The Sacramento Bee reports that in the Fulsom Unified School District, 145 kindergartners and seventh-graders were sent home on Tuesday last week (the first day of school) for failure to have the required vaccination documentation. By Friday, 98 of those students still had not returned to school. Do parents who oppose childhood vaccinations think the state is kidding? If they stick to their convictions they'll have to home-school their children.

I'm with the state and the school district on this one. It's time to hold the line against the anti-vaccine movement.

Tuesday, August 16, 2016

I'm Confused: Which Foods are Best/Worst for My Health?

Will eating more blueberries or broccoli help prevent cancer? Does oatmeal really reduce the risk of heart disease? How can we separate truth from fiction when it comes to the constant barrage of claims about certain foods?

The short answer is that it's difficult. That's because there's no easy way to prove that a certain food has a certain specific effect, given that so many other variables are in play at the same time. Most studies of specific foods and health rely on self-reported food consumption data, which is notoriously unreliable since people have a tendency to report what they think is the "right" answer. And such studies can't co ntrol for all the other variables in a person's life. So we're left, usually, with just a report of an "association" between a certain food and a certain medical effect. And as you know, an association (or correlation) doesn't prove cause and effect.

Want further evidence of the difficulty in evaluating the health effects of specific foods? Researchers from Harvard and Stanford Universities examined the recipes of a published cookbook and came up with a list of 50 common food ingredients. Then they surveyed the scientific literature to find out what had been published about that ingredient and the risk of cancer. Astonishingly, they found that 72% of the ingredients had been associated with either an increase or a decrease in cancer risk; some of the ingredients were reported to either increase or decrease risk in different studies.

I've stopped listening to the hype about any one food. I just try to eat a variety of foods, while keeping an eye on my weight. I'd like to report that I eat plenty of fresh fruits and vegetables and that I restrict my saturated fat intake, but that would be stretching it. You can do what you like; just don't believe that eating a lot of just one food is going to keep you from getting cancer, or prevent any other health problem for that matter.

Thursday, August 11, 2016

The U.S. Death Rate Increased in 2015

The death rate per 100,000 people in the U.S., also called the mortality rate, increased in 2015 for the first time in years, even when adjusted for age. The increase was slight but unusual; in a healthy society, death rates generally decline as a result of better nutrition and health care. So what happened in 2015?

For years, there has been a slow upward trend in the death rate among middle-aged whites, due to increases in drug- and alcohol-related deaths (see this blog, Dec. 13, 2015). Suicides have also been on the rise. In the past, these increases in deaths were more than offset by declines in deaths from specific diseases, such as heart disease and some cancers. But in 2015 the death rate from heart disease stopped declining. As a result, for the first time in a long time the overall death rate in the U.S. increased in 2015.

It would be unusual if this were the start of a new long-term trend in the U.S., for most developed and developing nations are still reporting annual declines in mortality. A long-term trend toward increases in mortality in the U.S. would be a worrying sign of a decline in overall societal health. Perhaps it will focus our attention on the rising death rate due drugs, alcohol, and suicides. Might many of these deaths be preventable?

Tuesday, August 9, 2016

Turning Sutures Into Sensors

A number of wearable and implantable sensors are now used to collect medical information from patients. It's possible, for example to wear devices that monitor body temperature, heart rate, steps taken, etc. A limitation of most wearable sensors is that they must lie relatively flat against the body. More importantly, none are very effective at monitoring the complex chemical changes that can take place within the body.

A breakthrough technology of the future may be to create "smart thread" - specialized types of sutures that could be used as sensors. Sutures are flexible, cheap, and easily implanted into the skin or even into organs. Researchers at Tufts University are studying how to coat sutures with conductive materials so that they might be used to monitor mechanical activity or chemical activity. Coating stretchable suture material with nanotubes and silicone causes the thread's resistance to change when they are stretched, so that by passing a small amount of current through the thread, sutures could be used to measure physical strain. By taking advantage of the wicking properties of some fibers (most notably cotton), sutures could be used to monitor the complex biochemistry of interstitial fluid in real time. Such sutures might be particularly useful in monitoring the progress of wound healing, where local conditions (pH, electrolytes, and glucose, for example) might be quite different from conditions elsewhere in the body.

So far, most of these ideas are just that: ideas. But the Tufts researchers are laying the groundwork with experiments in rats and in animal tissues such as chicken skin. Don't be surprised if someday your physician suggests using a smart suture to monitor some aspect of your health.

Wednesday, August 3, 2016

Hybrids and the Environmental Protection Act

In the 43 years since it was written, the Endangered Species Act (ESA) has played a key role in the recoveries from near-extinction of several species, including the bald eagle, the humpback whale, and the gray wolf. However, the ESA doesn't address hybrids - organisms produced when individuals of two different species mate and produce viable offspring. The problem of what to do about endangered hybrids has now come to the forefront, thanks (or no thanks) to a powerful new tool in biology, DNA sequencing.

The classic definition of a species is "a group of organisms that under natural conditions tend to breed within that group." Most species can't breed with other species and produce viable offspring. But there are exceptions; wolves, for example, can (and occasionally do) interbreed with dogs or coyotes. And that brings us to the problem of which wolves, if any, should be protected by the ESA.

The ESA currently recognizes (and protects) two species of wolves. Gray wolves are found primarily in the western U.S.; their population is recovering, thanks to protection under the ESA. Red wolves were once found in the southeast U.S. but now exist only in captivity; they, too, are protected. In addition, scientists have recently suggested that wolves in the eastern U.S. should also be listed as a separate protected species, to be called the Eastern wolf.

But now new research, using DNA sequencing, has revealed that the Eastern wolf and the red wolf are actually hybrids, produced by interspecies mating between gray wolves and coyotes. That creates a problem for the ESA. If Eastern and red wolves are just hybrids of two true species, should we attempt to save them? And if there is just one species of wolf, does its total population still warrant protection under the ESA?

The Environmental Protection Act is showing its age. It needs to be able to take into account new findings derived from DNA sequencing. And it needs to address what to do (if anything) about hybrids.

Tuesday, July 26, 2016

A New Map of the Cerebral Cortex

The map used in most textbooks to describe the functional regions of the cerebral cortex is admittedly rather old. Fortunately, it has just been updated. Using data collected as part of the Human Connectome Project, researchers examined over 1,200 brain scans looking at not one, but four features; architecture, function, connectivity and topography. They identified nearly 180 distinct areas of the cerebral cortex - more than double the number described in the past. The researchers also created a computer program that can recognize each area in an individual brain being studied.

What makes each region different and how they communicate with each other will likely be areas of active research for years to come. Of specific interest will be how the areas are involved in specific neurologic disorders. Dreaming big, we might imagine a future in which doctors could diagnose specific brain disorders from an MRI (magnetic resonance image), just by looking at changes in specific brain areas.

Thursday, July 21, 2016

We're Just One Step Away From a Superbug

The possibility that a strain of bacteria might develop total resistance to all known antibiotics (i.e., a superbug) continues to haunt us. Slowly but surely, more and more bacteria are increasing their resistance to antibiotics faster than we can create new antibiotics. No bacterium is completely resistant to all antibiotics yet, but a recent discovery suggests that we are just one step away from that point.

Right now, one of the most antibiotic-resistant of all bacteria is carbapenum-resistant Enterobacteriaceae (CRE for short). CRE has developed resistance to all antibiotics except an old antibiotic developed 50 years ago, called colistin. But now researchers have discovered a strain of E. coli bacteria that is resistant to colistin. If this strain of E. coli ever transfers its genetic material to CRE (the equivalent of bacterial mating), then we are in for real trouble.

Will it ever happen? No one knows. But bacteria have proven themselves to be highly adaptable. The era when antibiotics were the answer to bacterial infections may be coming to an end. We may have to find new ways to combat the bacteria of the future.

Saturday, July 16, 2016

Sexual Transmission of the Zika Virus

In healthy adults, the Zika virus causes only mild flu-like symptoms.  80% of infected adults never even know they are infected. However it's a dangerous virus nonetheless, because women who are infected during their pregnancies can give birth to infants with a birth defect called microcephaly.

When Zika first appeared in South America, it was believed that the virus was transmitted exclusively by mosquitoes that thrive in South American countries with warm, humid climates. However we now know that the Zika virus can be sexually transmitted. Until yesterday, all 14 documented cases of sexually transmitted infections in the U.S. had been caused by Zika-infected men (who infected their partners, either male or female). But now the CDC has reported the first documented case of transmission from an infected woman to her male partner in the U.S. The significance of sexual transmission is that it raises the possibility of an outbreak of Zika virtually anywhere in the world, not just in areas in which the Zika-transmitting mosquito is found.

Scientists are working feverishly on a vaccine to prevent Zika infections. It will take some time before one is available. In the meantime, pregnant women (and their male partners) should be aware of the dangers of traveling to countries where the Zika-transmitting mosquito is common.

Sunday, July 10, 2016

Nobel Laureates Support Genetically Modified Organisms (GMOs)

In an open letter published online, more than 100 Nobel Laureates are urging the environmental organization Greenpeace to stop their crusade against GMOs. Over 90% of the letter's signatories earned their Nobel prizes in the fields of physics, chemistry, or medicine. According to the letter's signatories, GMOs have been proven to be safe and have the potential to improve nutrition and feed a hungry world in the future. The letter suggests that opposition to GMOs is based on emotion and dogma, rather than facts. It concludes, "How many more poor people in the world must die before we consider this a 'crime against humanity'"?

The issue of the safety of GMOs is one of those areas in which the views of the public and of scientists are still far apart. A Pew Research Center study revealed last year that while 88% of scientists affiliated with the American Association for the Advancement of Science say that GMOs are generally safe, only 37% of the public thinks so.

In other related news, this month Vermont became the first state to require that food product labels indicate whether or not the product contains GMO ingredients. Other states are likely to follow suit. Clearly, the fight over GMOs is not over yet.

Monday, July 4, 2016

Prescription Contraceptives Via App or Website

It is now possible to obtain prescription contraceptives without ever having to schedule a visit to a doctor's office. A growing number of websites and apps allow you to fill out your personal and health information online or on an app and then have a videoconference or phone conversation with a licensed doctor; after approval of your prescription, your contraceptives (pills, patches, and in some cases even the morning-after pill) can be shipped directly to you.

Contraceptives are currently available only by prescription. Health professionals believe that contraceptives are so safe that they could be made available over-the-counter. However, over-the-counter availability would require approval from the FDA, an expensive and time-consuming effort most drug companies wish to avoid. In addition, the widespread availability of contraceptives without any medical approval at all would likely meet with opposition from conservative groups.

A few states allow pharmacists to write contraceptive prescriptions, but most do not. Web-and app- based services that connect patients to a doctor without a visit to a doctor' office are yet another way to make contraceptives more readily available. Health professionals hope that by making it easier for women to obtain contraceptives, these web-and app-based services will lead to a further reduction in the rate of unintended pregnancies.

For a description of some of the current websites and apps, see this article in the New York Times.

Monday, June 27, 2016

The Supreme Court Strikes Down a Texas Abortion Law

In a surprise ruling today, the U.S. Supreme Court struck down a Texas abortion access law (see this blog March 2, 2016) that severely restricted access to abortions in that state. The decision was a surprise because the court currently has only eight members, and it was widely believed that the court would be deadlocked on the issue until a ninth justice could be appointed after the presidential election.

Ever since Roe v. Wade, anti-abortionists have introduced legislation in many states designed to restrict access to abortion or make it more difficult. By striking down Texas's law, the court is signaling the states that they cannot restrict access to abortion simply by putting unnecessary obstacles in the way. In the majority opinion, Justice Breyer wrote, "We agree with the District Court that the surgical-center requirement, like the admitting-privileges requirement, provides few, if any, health benefits to women, poses a substantial obstacle to women seeking abortions, and constitutes an "undue burden" on their constitutional right to do so."

This new Supreme Court sets a fairly high bar for anti-abortion legislation; it must not introduce an "undue burden" on what is clearly a constitutional right.

Friday, June 24, 2016

Incorporating CO2 Into Solid Rock

Burning fossil fuels for energy releases CO2 gas into the atmosphere. Most of this CO2 stays in the atmosphere, where (as a greenhouse gas) it contributes to global warming and climate change. Some of it dissolves into the oceans, where it contributes to increased ocean acidity. These problems could be mitigated if the extra CO2 could be removed from the atmosphere somehow, but so far on one method has proven to be sufficiently cheap and effective. The most promising method so far has been to store the CO2 deep underground, in the hope that it will stay buried and not leak again to the Earth’s surface.

But now new research suggests that it may be possible to incorporate CO2 into minerals within solid rock, thereby sequestering it permanently. In a pilot study in Iceland, British researchers pumped 175 tons of CO2 into formations of basalt, a volcanic type of rock loaded with minerals that can combine readily with CO2. They found that within two years, 95% of the CO2 combined with these elements to become part of the rock itself. A larger study is underway to mineralize 10,000 tons of CO2.

One problem with this method is that so far it has only been shown to be effective in basalt. Although there are areas of basalt rock on Earth’s land surface, most of it is found on the ocean floor. At present, then, sequestering CO2 permanently in basalt may be too expensive to be the method of choice in most places. Still, if we ever finally have the will to do something about rising atmospheric CO2 levels, it’ll be nice to know that there’s a way.

Thursday, June 23, 2016

Should Cigarette Pack Labels Include Grotesque Images?

One way to get smokers to quit smoking, according to authorities in Australia, is to make cigarette packaging as unattractive as possible. In 2012, Australia commissioned a market research company to find the most unattractive color. Today, cigarette packs in Australia are a green-brown color known as “color 448c”. The packs are emblazoned with photos of the potential damage caused by smoking, along with messages such as “smoking kills” and “smoking doubles your risk of a stroke” displayed in letters larger than the brand names themselves. According to Australian authorities, the new packaging (new since 2012) is at least partly responsible for a steady decline in smoking in Australia. Other countries, including France and Britain, have taken note of Australia’s success and are planning to do develop their own similar rules for cigarette pack labels.

Attempts by the U.S. Food and Drug Administration (FDA) to require large warning labels and grotesque images on cigarette packs in the U.S have been blocked by lawsuits brought by tobacco companies. The tobacco companies argue that under the First Amendment right to free speech, they have a right to advertise their products without having the government use the companies’ packaging to carry the government’s anti-smoking message. In this country at least, our First Amendment rights to free speech trump the government’s interest in changing behaviour. The FDA is working on new cigarette pack labelling requirements that will pass muster with the courts, but that will take some time.

What do you think? Should cigarette packs in the U.S. carry prominent, grotesque images?

Saturday, June 18, 2016

Cell Phones and Cancer (Yet Again)

A recent study by government scientists again raises the possibility that radiation emitted by cell phones could cause cancer. In the study, rats were exposed to radiation of the type emitted by cell phones for 9 hours a day for their entire life span; a dose never approached by human use of cell phones. There was a barely significant increase in two types of cancer (of the heart and brain), but only in male (not female) rats. The 74-page report is labeled 'preliminary' and was not peer-reviewed, meaning that it has not yet been reviewed by other independent scientists in the same field. That's generally a no-no in terms of establishing a paper's scientific validity.

Although some media duly reported (yet again) that cell phones may cause cancer, this report just isn't very convincing. For a critique of the report, see the article in the New York Times. For an extensive and sometimes humorous analysis, see this commentary.

Friday, June 17, 2016

If You're Healthy, You Don't Need Probiotics

The National Institutes of Health (NIH) defines probiotics as live bacteria that are "similar to beneficial organisms found in the gut." They're found in yogurt, fermented milk, soy products and some juices, as well as (these days) in probiotic capsules, pills, and powders. Many people make sure to get plenty of probiotics in the belief that a healthier population of gut bacteria makes for a healthier individual. It's a trend strongly encouraged by the rapidly growing probiotics dietary supplements industry.

The idea that probiotics may be good for you comes from the reports that patients with certain gastrointestinal conditions can benefit from taking probiotics. For example, patients with ulcerative colitis or who have diarrhea due either to antibiotics or to a particularly bad gut bacterium called Clostridium difficile may benefit from taking probiotics to more quickly restore their gut microbiota to normal.

What if you're healthy and just want to stay that way - should you spend your hard-earned money on probiotics? The answer, according to the latest research, is "no". The authors of the research reviewed the findings of seven studies that specifically identified the composition of gut bacteria in healthy people, before and after they took probiotics. They report that in healthy people, probiotics had essentially no effect on the final composition (in terms of both variety and number) of gut bacteria. In other words, healthy people develop and maintain a healthy steady-state population of gut bacteria naturally, on their own. Taking probiotics is only likely to be helpful when the gut's normal microbiota have been severely disrupted by antibiotics or disease.

Probiotics probably won't do you any harm, mind you; it's just that if you're healthy, they're unnecessary.

Saturday, June 11, 2016

California's End-Of-Life Law Takes Effect

Last Fall the California legislature passed a bill called the End-Of-Life Option Act (see this blog, Sept. 17, 2015). Following the signature of governor Jerry Brown in October, the new law went into full effect on June 9th. The new law gives terminally ill patients the option of terminating their lives at a time and place of their own choosing. The law was inspired by the plight of Brittany Maynard, a terminally ill young Californian who chose to move to Oregon in 2014 to take advantage of a similar law already in effect there.

The new law is not "assisted suicide". Patients who might choose to take advantage of the law will die soon anyway. The new law simply allows them to choose a more gentle way of dying, at a time and place of their choosing. The preferred term is "death with dignity" or "aid in dying".

In order to request a prescription for life-ending medication in California, the patient must be a California resident at least 18 years of age who is mentally capable of making an informed decision and who has been diagnosed by at least two physicians with a disease that will result in their death within six months. In addition, there's a long list of requirements that must be met before a prescription for life-ending medications is approved, as well as certain restrictions on how the drugs can be used (the patient must self-administer the drugs, for example). The experience of the only other states with similar laws (Washington, Oregon, and Vermont) is that only about half of all patients who are issued prescriptions for life-ending medications actually use them.

Friday, June 3, 2016

What Is an "All-Natural" Food Product?

What does the term "all natural" mean to you? Some people favor foods with a "natural" or "all-natural" label because they think it means that they are better for you. It's a feel-good term that influences consumers, for sure. But legally it means absolutely nothing.

More than a hundred class-action lawsuits have been filed against food manufacturers who have used the terms "natural" or "all-natural" on foods containing all sorts of things, including pesticides, hormones, genetically modified organisms (GMOs), and artificial ingredients. All of the lawsuits have failed in court. The basic problem is that the Food and Drug Administration (FDA), the agency charged with regulating our food industry, has never adequately defined the terms. And without a definition, judges have been reluctant to rule against food manufacturers who use the terms lightly.

That may change soon. For two years the FDA has been receiving comments from the public on what they think "natural" means. The agency is now reviewing the 7,600 comments it received and may issue a final definition of the term later this year. One possible definition might be "foods not made by humans and subjected to little or no processing", such as ground nuts, whole grain flours, and foods processed by traditional techniques such as roasting, drying, fermenting, and smoking.

Once the FDA has officially defined "natural", the makers of food products will either have to comply with the new definition or face lawsuits that they may actually lose.

Saturday, May 28, 2016

ALS and Environmental Pollutants

A recent study raises the possibility that exposure to certain environmental pollutants may contribute to the development of ALS (amyotropic lateral sclerosis, a degenerative nerve disease.) The authors of the study measured the concentrations of more than a hundred specific environmental pollutants in the blood of patients with ALS, using normal persons as controls. They found that the concentrations of some of the pollutants were significantly higher in the blood of patients with ALS than in normal patient controls. The authors concluded that certain environmental pollutants "may represent modifiable ALS disease risk factors."

It's a good study, but we need to be careful not to read too much into it. The data did not prove that environmental pollutants cause ALS. In fact, the data didn't really prove anything at all; they only revealed that an association exists between ALS and environmental pollutants. And as we know, an association does not prove causation. The authors' choice of the word "may" in their conclusion was deliberate and accurate.

And yet, this is still a very important finding because it gives us a possible clue to ALS that could be pursued by future scientific studies. Can the findings in this study be confirmed by other researchers? Are there any animal models that develop neurological conditions similar to ALS, and if so, is their condition made worse by exposure to environmental pollutants under strictly controlled conditions in the laboratory? Do any of these pollutants affect the biochemistry or development of embryonic nerve cells grown under laboratory conditions?

There's a lot more to do before we know for sure whether environmental pollutants contribute to the development of ALS. This current study represents a starting point.

Tuesday, May 24, 2016

The 'Textalyzer' Can Prove You're Texting While Driving

It's illegal to text while driving in nearly all states now. But people do it anyway, perhaps because they think the likelihood of getting caught is slim, and perhaps because in some states its still a relatively minor infraction.

If you drive and text, you should know that the likelihood of getting caught and punished may soon go up. That's because now there's a device called a 'textalyzer' that can test your phone for recent use. In addition, the state of New York is now considering a bill that would put the offense of texting-while-driving on a par with driving-while-drunk.

The textalyzer is a product of Cellebrite, an Israeli company that is a leader in "mobile device forensic solutions". The textalyzer is a portable device that can 'read' your phone to tell exactly when it has been in use. The device could provide detailed information down to the level of content of the text itself, but for reasons of privacy its use will probably be restricted to just determining the precise timing of the phone's use. In an accident investigation, that would be enough for a conviction.

New York may be the first state to use the textalyzer to tell if drivers have been texting while driving and to establish stiff penalties for the offense. If they're successful you can expect other states to follow suit.

Tuesday, May 17, 2016

Do NSAIDs Speed the Rate of Healing of Tendinitis?

Many athletes routinely use nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen and ibuprofen to blunt pain and hopefully shorten the recovery time from acute tendon injuries, called tendinitis. But are the NSAIDs really helpful other than that they blunt the pain? Do they speed the healing process?

Apparently not, according to an editorial in the British Journal of Sports Medicine. For starters, tendinitis is actually a misnomer; "-itis" means inflammation, and researchers have found that although tendon injury generally is characterized by pain and swelling, it is actually not accompanied by the appearance of the immune cells normally associated with inflammation. Therefore, what we tend to call tendinitis should probably be called tendinopathy ("-pathy" means injury). And while the NSAIDs do block the pain associated with tendinopathy, they also inhibit the release of prostaglandins which are normally involved in the production of collagen, thought to be necessary for tendon repair. So if anything, NSAIDs are more likely to slow the healing process than speed it up.

So, what to do? It's probably okay to take NSAIDs over the short-term (up to a week) to relieve acute pain. In the long term, gentle stretching and light weight-bearing exercise of the injured tendon will do more good than continued use of NSAIDs. Consult your doctor or physical therapist for the final word on your particular situation.

Wednesday, May 11, 2016

The FDA Bans E-Cigarette Sales to Minors

Last week the U.S. Food and Drug Administration (FDA) finalized new rules that lump e-cigarettes in with tobacco products, in effect giving the FDA full regulatory authority over e-cigarettes. As a consequence of that change, sales of e-cigarettes to persons under the age of 18 will now be banned. The new rules take effect in 90 days.

E-cigarettes don't contain tobacco. Nevertheless, health authorities have long argued that because they contain nicotine and other toxins they are not completely safe, and in any case they should not be available to children. Calling e-cigarettes tobacco products for purposes of regulation was an interesting move, because in addition to the ban on the sale of e-cigarettes to minors, it means that manufacturers will be prevented from making misleading claims about their products and will need to disclose all ingredients to the FDA.

E-cigarette use among persons under 18 has risen dramatically in the past few years. Over the same time period the use of tobacco cigarettes by persons under 18 has declined slightly. Cause-and-effect? No one knows for sure, but there is some tantalizing evidence to suggest that it might be. One study reports that there was a small but statistically increase in smoking among underage teens in states that banned e-cigarette sales to minors, compared to states that have not banned e-cigarettes.

So, are e-cigarettes a good thing, or a bad thing? If they help current smokers to quit and/or reduce the rate at which young people begin smoking, that would be good. If they lead to a whole new generation of nicotine addicts or if we find that e-cigarettes' other ingredients are harmful to human health, that would be bad. It may be a few more decades before we know for sure

Wednesday, May 4, 2016

Stent Retrievers Improve the Odds of Recovery From a Stroke

A device called a stent retriever can improve the odds of recovery from an ischemic stroke, brought on by a clot that blocks blood flow in an artery in the brain. The stent retriever is a tube-shaped wire mesh device similar to the stents that are used to open blocked arteries in the heart. In the case of a stroke, however, the device is inserted into the blocked artery in the brain, where it enmeshes and entraps the clot so that it can be pulled out.

Stent retrievers (and the surgeons trained to use them) have been available for a while now in hospitals with state-of-the-the art endovascular treatment units. Generally that does not include your local clinic or small hospital; more likely it's a large regional hospitals. That may prove to be important, because new findings show that the stent retriever technique is highly effective IF it is done soon after the stroke. Using "functional independence" as the definition of recovery from a stroke, 91% of stroke patients recover if the stent retriever technique is performed within 2 1/2 hours of the onset of stroke symptoms. However, recovery percentages decline rapidly if treatment is delayed. The recovery percentage declines an additional 10% if treatment is delayed another hour, and another 20% for each additional hour after that. By 5 1/2 hours after the stroke, recovery after the stent retrieval procedure is only about 40%.

Stent retrievers are shaping up to be a lifesaver for stroke victims with quick access to a well-equipped health care center. But burn this into your brain; in the case of a stroke, getting to treatment (any treatment) quickly is absolutely essential. Like the stent retrieval procedure, clot-dissolving drugs also are more effective when they are administered soon after a stroke.

Monday, May 2, 2016

First Child Born Without Kidneys

The first child ever to survive a condition called bilateral renal agenesis (the failure of kidneys to develop in the fetus) will be three years old this July. Young Abigail Beutler is the daughter of Congresswoman Jaime Herrera-Beutler from Washington state and her husband, Dan.

Bilateral renal agenesis occurs in about 1 in 5,000 pregnancies. In the past, such fetuses always died before birth. That's because the urine produced by the fetus's kidneys is the source of most of the amniotic fluid that bathes a fetus; without adequate amniotic fluid, the fetus's lungs fail to develop normally. Representative Herrera-Beutler's fetus (the future Abigail) was kept alive during gestation by an experimental procedure in which Rep. Herrera-Beutler received intra-abdominal injections of saline throughout late pregnancy, simulating amniotic fluid. The technique worked, and Abigail was born successfully on July 15, 2013.

But that was only the beginning of young Abigail's survival story. Because she was born without kidneys, she was on dialysis from birth until she was old enough for a kidney transplant. Fortunately, both of her parents were good matches for the transplant. On Feb. 8 of this year when she was 2 1/2 years old, Abigail received one of her father's kidneys. Both father and daughter are doing well.

Call it yet another lifesaving advance in medicine. We can probably expect the saline injection technique used in this case to become the standard treatment for fetuses diagnosed with bilateral renal agenesis.

Thursday, April 28, 2016

Whatevever Happened to Filbanserin, the "Female Viagra" Drug?

Last year we were talking about a new libido drug for women, called filbanserin (see this blog, July 2, 2015.). The drug was supposed to improve women's sex lives, giving them the same options men have had for years with Cialis and Viagra. The drug was poised for approval by the FDA, even though there were concerns that it wasn't very effective. Whatever happened to it?

The story of filbanserin (trade name Addyi) is one of hype, greed, and mismanagement. filbanserin was originally under development as a drug to treat depression. Then it was discovered that it seemed to improve some women's satisfaction with their sex lives. Sensing that there might be a really big market for the drug, a small company called Sprout Pharmaceuticals bought the rights to the drug. Twice they tried get it approved by the FDA. When filbanserin was finally approved last August, the company's sales force of 14 national/regional sales managers and 150 sales representatives was all set to promote and sell the drug.

But just one day after FDA's approval of filbanserin, Sprout Pharmaceuticals was bought by an even bigger pharmaceutical company, Valeant Pharmaceuticals for (wait for it...) a whopping $1 billion. (Big fish swallows helpless little fish.) Valeant was making a name for itself on Wall Street by buying up other smaller pharmaceutical companies with patented drugs and immediately raising the drugs' prices. Yes, that's the same Valeant Pharmaceuticals that is now under federal investigation for predatory drug pricing practices.

Valeant's stock price has plummeted 85% since last year. As part of its efforts to save itself, Valeant dismissed the entire Sprout Pharmaceuticals sales force and shelved all plans to sell the drug, saying they might reintroduce the drug later this year. We'll see.

Only a few thousand prescriptions for the drug were ever written. Forget about it: it wasn't a very effective drug anyway.

Monday, April 25, 2016

Determining Who Can't Tolerate Statins

For years now, a class of drugs called statins have been the treatment of choice for lowering LDL cholesterol levels. They're cheap (pennies a day), effective, and safe. The problem is that 5-20% of patients say they can't tolerate the statins because of muscle-related side effects, including muscle pain and weakness.

A new class of class cholesterol-lowering drugs, called PCSK-9 inhibitors, avoids the muscle-related side effects. However, the big downside to the PCSK-9 inhibitors is that they are very expensive - approximately $14,000 a year. For that reason, insurance companies would like the PCSK-9 inhibitors to be used only by the few people who are truly intolerant of the statins. But how is intolerance to the statins to be defined, other than by the patients and their physicians?

A recent study showed how big a problem this is. Researchers wanted to explore the effectiveness of several newer LDL cholesterol-lowering drugs in statin-intolerant patients with very high cholesterol levels. To find such patients, they recruited more than 500 patients who had tried two or more statins and claimed that they could not tolerate them because of muscle pain or weakness. The patients were randomly assigned to take a statin (atorvastatin) or a placebo for ten weeks. Then the drugs were switched for an additional 10 weeks. It turned out that only 43% of the patients could be defined as statin-intolerant; that is, they reported muscle-related symptoms while they were on the statins but not while they were on the placebo. 26% of the patients reported muscle pain only while on the placebo, 17% never experienced muscle-related symptoms on either the statin or the placebo, and 10% complained of pain on both the statins and the placebo.

The bottom line is that fewer than half of all patients who say they are statin-intolerant actually are statin-intolerant. Because the PCSK-9 inhibitors are so expensive, some insurance companies are suggesting that patients who request them should be tested for statin intolerance (as the patients in the above study were) before insurance will pay for the new drugs.

What do you think? Should patients be required to submit to several months of testing before their (and your) insurance company agrees to pay for a $14,000-a-year drug for them?

Friday, April 22, 2016

A "Liquid Biopsy" for Lung Cancer

There are several known possible genetic mutations in non-small cell lung cancer (NSCLC), the most common form of lung cancer. Depending on which of several mutations it is, the cancer cells will respond differently to different treatments. The problem is that in the past the only way to tell which type of genetic mutation was present, and hence which treatment would work best, was a biopsy, which is invasive and often painful. A biopsy is certainly worth doing, of course, if it's required for adequate diagnosis and treatment, but not if there were an easier or better way.

Now scientists may have found that easier way. When cancer cells die (or when any cells die, for that matter), their DNA is spilled into the blood. By testing a sample of the patient's blood for the various possible genetic mutations found in NSCLC cells, it should be possible to identify the specific genetic mutation present, and thus to know which of several treatment options is likely to work best.

That's precisely what research conducted at the Dana Farber Cancer Center in Boston has found. The researchers have identified two key genes found in NSCLC cells using just a single test tube of blood. Technically known as plasma genotyping, the new test is also referred to as a "liquid biopsy" because it serves the same function as a traditional tissue-based biopsy, only using a liquid (blood).

In addition to helping physicians determine which of several treatment options to offer the patient, the liquid biopsy can also be used to determine how well the patient is responding to the treatment. If the cancer treatment is working, for example, the unique genes found in NSCLC cells should begin to disappear from future liquid biopsies.

Thursday, April 14, 2016

Exercise Doesn't Increase Bone Strength

It's a commonly-held belief that weight-bearing exercise is a good way to increase bone density and strength. But it isn't true. The notion comes from the fact that you do lose bone mass if you are bed-ridden for a long time (or if you are an astronaut in space). But the inverse idea; that you gain bone mass when you exercise, doesn't seem to be true, according to an article in The New York Times that summarizes recent research. The available research shows that exercise only increases bone mass about 1% - not enough to have much effect on overall bone strength. Apparently, just the effects of gravity on your normal types of activity are enough to keep your bones healthy.

However, exercise does reduce the risk of bone fractures, especially in older people. Apparently that's not due to stronger bones, but to better balance and/or stronger muscles, both of which reduce the risk of falling.

Saturday, April 9, 2016

The First U.S. Uterus transplant Has Failed

The first attempted uterus transplant in the U.S. has failed. The patient, Lindsay MacFarland, appeared before reporters on February 26, two days after the operation, to thank The Cleveland Clinic and her doctors. But just a day later the uterus was removed because of complications caused by a yeast infection. The announcement of that failure came only yesterday. For more details and photos, see the article in the Daily Mail.

The Cleveland Clinic had anticipated that this would just be the first of ten such surgeries in order to evaluate the potential of such transplants on a wider scale. The protocol may have to be modified in an effort to reduce the chances of future failures.

As I noted in a previous post (see this blog, Nov. 23, 2015), a uterus transplant serves no valid medical purpose other than to allow an infertile woman to experience pregnancy. In a statement to the New York Times last year Mrs. MacFarland, the mother of three adopted children, said, "I crave that experience. I want the morning sickness, the backaches, the feet swelling. I want to feel the baby move. That is something I've wanted for as long as I can remember. "

Do you think it will be worth the risk and expense for surgeons to perfect this surgery? (Mrs. MacFarland's surgery was paid for by a government-funded research study.)

Thursday, April 7, 2016

Easier Access to the Morning-After Pill? Not in Arizona!

Just last week the FDA established new labeling guidelines for the use of mifepristone, the so-called "morning-after pill" (see this blog Apr. 1, 2016). The new labeling guidelines were expected to make mifepristone more widely available in six states that had specifically passed laws requiring physicians to adhere to FDA labeling guidelines when using the drug. The previous labeling guidelines written in 2000 are no longer considered "best medical practice". But they were much more restrictive than the way most physicians were using the drug, so in effect they limited access to medication abortions.

But wait a minute! Just one day after the FDA established the new labeling requirements for mifepristone, Arizona's governor signed into law legislation that declares that mifepristone may only be used in accordance with the old protocol as it existed at the end of 2015. The new law will take effect this Summer, when the legislature is conveniently out of session. Apparently the Arizona legislature knew the FDA ruling was coming and made a preemptive strike against it before adjourning. The intent is clear, for there can be no medical justification for sticking to an outdated protocol that restricts access to a safe and effective drug.

We'll see how this plays out in the courts and in other states that may choose to copy this approach. At the very least, it is likely to delay the availability of mifepristone in Arizona by a year or so.

For more on this subject, see the article in The New York Times.

Monday, April 4, 2016

A Temporary School Closure Due to Measles

A single case of measles in a preschool student in California has prompted the county's Public Health Department to close the preschool for several days. In addition, the health department has informed all parents that children who are not fully vaccinated will not be allowed to return to school for an additional week and a half, even though the school will be reopened for vaccinated students.

Measles is a highly contagious disease. Although most infected individuals recover fully without incident, measles still causes an estimated 140,000 deaths worldwide per year. Health officials stress that approximately 95% of the individuals in any community need to be vaccinated in order to achieve "herd immunity", in which the disease is not able to spread rapidly throughout the community once an individual is infected. Vaccination rates are well below that number in some counties in California.

Reading between the lines, this may be a situation where the health department has exercised its authority and fired a warning shot across the bow of parents who have (so far) refused to have their kids vaccinated. California passed a law last year that requires children to be vaccinated in order to attend school (see this blog July 8, 2015). The law, which takes effect on July 1st for this year's crop of preschoolers, no longer allows for exemptions based on personal or religious beliefs. At the school in question only 43% of the children have been fully vaccinated, according to the Huffington Post. If they are not vaccinated by this Fall they will have to be home-schooled.

Anti-vaxxers may be in for a tough fight on this issue. Their main argument against vaccinations seems to have shifted recently from "vaccines cause autism" to "it's a matter of choice". But they do not have the choice to endanger the health of others, according to the State of California.

Friday, April 1, 2016

New Guidelines for the Use of the Morning-After Pill

The FDA has published new guidelines for the use of the "morning-after" pill mifepristone (MifeprexR), used to affect a medication abortion. The new guidelines will permit the pill to be used up to 10 weeks after pregnancy, three weeks longer than previously permitted. The new guidelines will also require only two visits to a physician for a full course of treatment, making the drug easier to obtain and use. Many doctors had already been using mifepristone according to the new guidelines (meaning that they were using it "off-label" at the time), because it has been known for years that the pill is safe and effective up to 10 weeks after pregnancy.

The new FDA guidelines are a setback for the anti-abortion movement. In an effort to make access to mifepristone as difficult as possible, anti-abortion advocates had convinced the legislators of six states (Arizona, Arkansas, Ohio, Oklahoma, North Dakota, and Texas) to pass laws prohibiting off-label use of the drug. The unspoken goal of these laws was to make it harder to obtain and use mifepristone by forcing patients to see a physician three or more times instead of just twice and limiting the drug's use to just seven weeks after pregnancy. The tactic worked; one study found that medication abortions fell by more than 80% in Ohio after introduction of the restrictive law in that state, according to CBS News.

Under the new guidelines, the way that most physicians currently prescribe mifepristone will no longer be "off-label".  As a result, medication abortions should again become more common in those six states that had attempted to restrict them.

Monday, March 28, 2016

The Rate of Climate Change Could Accelerate

A respected group of climate scientists has concluded that climate change and its negative effects are likely to occur much more rapidly than previously thought. The authors predict that within just 50-150 years Earth will experience massive storms, the disappearance of large portions of the polar ice sheets, and a rise in ocean levels of several meters; enough to inundate some coastal cities. According to the authors, we are already in the early phase of an accelerated period of temperature rise similar to one that occurred naturally about 120,000 years ago. By the time that one was over, ocean levels had risen by a whopping 20-30 feet.

What is new about this prediction is the rapidity of the changes; the authors conclude that they could occur in just a couple of human generations, and not over thousands of years.

While not all scientists are absolutely convinced by this paper, it appears that they are taking it seriously. It is likely that this paper will cause other scientists to examine the data to see if it fits with their own predictive models. Little by little, through the scientific process of testing and retesting, we come closer and closer to the truth. We cannot afford to get this one wrong.

Sunday, March 27, 2016

Using "Incompatible" Kidneys for Transplant

Every year, hundreds of patients who need a new kidney die before a donated kidney (either from a living person or a cadaver) can be found for them. The basic problem is that the donated kidney has to be a good immunological match for the recipient (the patient) or his/her immune system will attack the donated kidney, ultimately causing it to be rejected. But before we blame the immune system for this problem, remember that the immune system protects us from infectious diseases precisely because it attacks foreign tissues and cells, such as bacteria.

Knowing how the immune system works, scientists think they may have found a way to circumvent the system so that any kidney could be used in any recipient. It would mean that a husband could donate to his wife, for example, or any friend could donate to a friend in need. This would be a huge advance, because the chance of a good immunological match between two unrelated individuals is around one in 100,000 or more.

In the procedure, called "desensitization", the patient's antibodies are filtered out of the blood. (They're replaced by an infusion of other antibodies to provide some temporary protection from infection.) After the kidney transplant, the patient's immune system slowly replenishes the patient's own antibodies, but for some reason these new antibodies are not as likely to attack the foreign (donated) kidney.

  According to a recent summary study, the 8-year survival rate of desensitized patients who received an incompatible kidney was 76%. That compares favorably to the 44% survival rate of a matched group of control patients who simply remained on the transplant list.

Friday, March 25, 2016

Zika Virus Infections and Fetal Damage

We're learning more about the effect of a Zika virus infection on an unborn fetus every week. Two new reports strengthen the link between Zika virus infection during pregnancy and an increased risk of birth defects, most notably microcephaly. One ongoing study is following pregnant women in Brazil who were infected with the Zika virus during pregnancy. Forty-two of the women agreed to have regular ultrasounds to study the progression of the fetus. Among those 42 women, the fetus has already died or appears to suffer from serious birth defects in 12 of the women. Only 8 of the women have given birth so far, and in all cases the ultrasound diagnoses were accurate. The study will continue until all of the women have given birth, but the preliminary results are pretty dismal; a 29% rate of fetal death or significant fetal problems.

In a second laboratory-based study, researchers showed that the Zika virus appears to attack and kill human neural progenitor cells that will ultimately form the cortex of the brain. In this study, the researchers cultured various fetal cells and then exposed them to the Zika virus. The cultured neural progenitor cells were infected and killed by the virus, whereas several other types of cultured fetal cells were not.

There is no vaccine yet for the Zika virus. Although research into Zika vaccines is underway, it is likely to be several years before one is available. And because this is the first major outbreak of the virus, there are almost no women who are currently immune to the virus by virtue of a previous exposure. The clock is ticking.

Tuesday, March 15, 2016

More Support for Early Exposure to Food Allergens

The hypothesis that early exposure to certain food allergens may reduce the likelihood of children developing food allergies later in life received support recently from two additional studies. The first study, by the same authors that carried out the study described last year (see this blog Mar. 9, 2015) shows that the protective effect of being exposed to peanuts at an early age seems to last a long time, even when peanuts are not consumed at all for a full year. The second study extended these findings by showing that the protective effect of early exposure to allergens is not restricted to peanuts, but seems to apply to other of the usual food allergens such as eggs and wheat. At the very least, early exposure to these allergens does no harm.

The World Health Organization currently recommends that infants be fed only milk for the first six months. With more studies like these two, that recommendation may have to be changed in the future.

Tuesday, March 8, 2016

Maria Sharapova to be Suspended From Tennis

The latest athlete caught up in a doping scandal is Russian tennis player Maria Sharapova, currently ranked #7 in the world by the World Tennis Association and the highest-paid female athlete for the past eleven years. She earned more than $29 million last year, most of it from endorsements.

Apparently Ms. Sharapova tested positive at the Australian Open tennis tournament for a banned substance called meldronium, also known as mildronate. Meldronium is approved in Russia and the nearby Baltic countries for the treatment of ischemia (an inadequate supply of oxygen to the heart, due to a reduced blood flow). Its main use is for patients with angina or heart failure, but apparently it improves blood flow enough that it also improves athletic performance, or at least that's what athletes think. It was banned last year by the World Anti-Doping Agency (WADA) after a 2015 study showed that 17% of Russian athletes, and just over 2% of athletes worldwide, were using it. It is not available in the U.S or Europe.

Ms. Sharapova claims that she's been using the drug since 2006 for "several health issues I was having in 2006", and then just failed to check the list of banned substances in 2015 when meldronium was added to the list.  Really?  You be the judge.

Ms. Sharapova faces a possible suspension from tennis competition of up to four years. Her sponsors are watching the situation closely; several of them (Nike, Porsche, and Tag Heuer) have already suspended their relationships with her. It would be sad if this is how her distinguished career ends.