Thursday, May 25, 2017

Sunscreen Use in Schools

Did you know that in most states, teachers and school nurses in public schools cannot apply sunscreen to students? That's because the FDA classifies sunscreen as an over-the-counter drug. Technically, students can't even apply sunscreen themselves unless they have a signed note from a doctor and their parents.

The rule strikes most parents and school administrators as odd. It's hard to see who could be harmed by applying sunscreen to a child who needs it, unless of course the child were allergic to an ingredient in the sunscreen. And that would be an unrelated problem entirely.

A bill to allow students to use sunscreen in schools stalled in Congress last year. Not willing to wait for Congress, some states are taking action. Seven states have already passed laws that allow students to use sunscreen in school, and eight more states are considering such laws, according to a CBS news report. It makes sense; Congress has a lot on its plate, and this is something states can deal with on their own.

Sunday, May 21, 2017

A New Outbreak of the Ebola Virus in 2017

On April 22 a 45-year-old man in a remote area of the Democratic Republic of the Congo (DRC) was diagnosed with the Ebola virus; call him the new "patient zero". In less than a month there were 20 more suspected cases and three deaths. Is this the start of a new outbreak? And if so, what is being done to prevent another outbreak like the 2014-2016 outbreak that killed over 11,000 people in Guinea, Sierra Leone, and Liberia?

It would be encouraging to think that "it'll be different this time", and maybe it will. For one thing, Merck has developed a vaccine that appears to be effective against the 2014-2016 strain of Ebola. There are already stockpiles of the vaccine on ice. But the vaccine is still considered "experimental". It has not yet been approved by the FDA, and so it can only be used in carefully monitored clinical study protocols designed to document the vaccine's safety and effectiveness. The DRC does not yet have an approved clinical study protocol on file, according to an article in Science. The government will need to decide whether standard containment strategies are likely to suffice, or whether it can establish an approved study protocol quickly enough to be able to vaccinate people at risk before the outbreak gets much worse.

You might think it would be a no-brainer to establish a clinical study protocol. It is not. Requirements would include the ability to keep the vaccine refrigerated the vaccine at all times - no small task in remote region of the country. Furthermore, an approved clinical study protocol would require extensive record-keeping, including follow-up of all vaccine recipients for an extended period of time. There's even a requirement for ethical oversight and for obtaining informed consent from all vaccine recipients.

And so we wait. We wait to see what the DRC does about this latest outbreak, and whether the outbreak spreads.

Friday, May 19, 2017

Creating Eggs From Skin Cells

Some day it may be possible to produce human babies from skin cells, according to an editorial in Science Translational Medicine.  It's all due to a new technique called in vitro gametogenesis (IVG).

IVG refers to the technique for producing eggs or sperm (gametogenesis) outside the body (in vitro). The technique only became possible because, a decade or so ago, scientists learned how to produce undifferentiated stem cells known as induced pluripotent stem cells (iPSPs) from mature somatic cells.  Since that time iPSCs have been used to create various kinds of specialized somatic cells, including neurons to heart muscle cells.  And just recently, iPSCs derived from mouse tail cells were used to create fully functional gametes (eggs).  When fertilized with sperm, these eggs created by IVG were able to develop into healthy baby mice.  Sperm have not yet been fully developed from iPSCs, but surely they will be.

The ability to produce eggs and/or sperm from somatic cells raises all kinds of possibilities for how the procedure might be used (or misused, depending on your perspective).  If an egg could be grown from a male's skin cell and then fertilized by IVF with sperm from a male partner, gay couples could have babies that were genetically related to both of the males.  Of course a female surrogate mother would be necessary to carry the embryo to term, but surrogate mothers are not uncommon these days. Taking it one step further, if both eggs and sperm could be created from a male's skin cells, the male could (again, with the help of a surrogate) have a child that was entirely genetically his. These are scenarios that may need to be dealt with in your lifetime.  (Note that since females have no Y chromosome, IVG could only produce eggs from a female; never sperm.)

On the positive side, the ability to produce eggs from skin cells could mean that overcoming infertility would become easier and cheaper.  Right now, women undergoing an IVF procedure must undergo a complicated cycle of ovary stimulation and egg retrieval; with IVG, that would be unnecessary.  Furthermore, IVG could be used to produce an almost infinite supply of eggs, whereas only a few eggs are produced with each IVF cycle.

How do you think IVG should be used?

Thursday, May 11, 2017

A Second Drug is Approved to Treat ALS

The FDA has approved a second drug to treat amyotropic lateral sclerosis (ALS), also known as Lou Gehrig's disease. ALS is a progressive, debilitating, neurodegenerative disease that is usually fatal within 3-5 years. The new drug, called Radicava, slows the progression of the disease somewhat after six months of use; apparently that was enough for the FDA to approve the drug.

Before you get too excited, though, here are some facts about the new drug; 1) It must be given intravenously. That means that the patient must have a permanent IV port installed, which poses an infection risk. 2) The drug is only partially effective. Patients using the drug won't feel better; their health will just decline less rapidly. 3) It's expensive - $146,000 a year, according to its manufacturer.

The first drug to treat ALS, called riluzole, costs only about a tenth as much as Radicava.  Riluzole extends the life of ALS patients by 2 or 3 months; whether Radicava does the same isn't yet known.

If you had a fatal disease and were expected to live only 5 more years, would you pay $146,000 per year to slow the rate of disease progression just a little, or to live an extra 2-3 months? That's a judgment call only you can make. But your insurance company might balk at the price of this drug, considering its minimal effectiveness.

Sunday, May 7, 2017

When Did Humans Reach the Americas?

Until now, the best available evidence had indicated that humans probably reached the Americas about 20,000 years ago.  But now a new paper published in Nature raises the possibility that humans reached the Americas as early as 130,000 years ago.  The new findings could force a re-thinking of when, how, and by whom the Americas were colonized.

The new paper focuses on an archaeological site in California, where smashed and broken bones of a mastodon were found intermingled with what are reported to be crude stone tools.  Uranium/thorium dating shows that the bones are a whopping 130,000 years old.  The authors propose that the bones were deliberately smashed, leading to the conclusion that humans must have been in California at least as early as 130,000 years ago.

The findings are intriguing, but we'll probably have to wait for corroborating evidence before everyone accepts the new date.  For starters, it would help if we could find human bones that old; so far, no human bones older than about 20,000 years have ever been found in the Americas.  And then there's the question of how they could have gotten to the Americas in the first place.  The humans who colonized the Americas about 20,000 years ago crossed over from Asia via a land bridge that existed at the time between current-day Russia and Alaska.  That land bridge probably didn't exist 130,000 years ago.  They could have arrived by boat, but that would presume a higher degree of sophistication than implied by primitive stone tools.

Finally, there's the question of who these people were, if indeed they ever existed.  DNA evidence indicates that Native Americans can trace their ancestry back to a common ancestor who lived about 20,000 years ago.  If a band of humans arrived more than 110,000 years before that, they must have died out without leaving a continuous line of descendants.

Thursday, May 4, 2017

An artificial Womb

A baby that is born at 23 weeks of gestation (about halfway through the normal gestation period) has only about a 50% chance of surviving. The main problem for babies born prematurely ("preemies") is that they struggle to breathe, for their lungs are not yet fully developed. Their underdeveloped hearts, too, have a hard time pumping all of the blood that the baby requires outside of the womb. In the womb, the baby's still-developing lungs are filled with amniotic fluid, and so the baby doesn't breathe at all. Oxygen is delivered to the baby (and CO2 is removed) by the blood circulating between mother and baby via the umbilical cord.

In an effort to increase the chances of survival of very premature preemies, scientists are now working to develop an artificial womb. So far, the artificial womb has only been tried with premature lambs in an experimental setting, but the early results look promising. The artificial womb looks a bit like a large re-sealable bag. Upon delivery, a premature lamb is put into the bag, and the bag is then filled with artificial amniotic fluid and sealed to prevent infections. Ports provide access to the umbilical cord and allow for exchange of amniotic fluid. The umbilical artery and vein are cannulated so that blood can be exchanged with the lamb, just as it would be in the womb. Premature lambs have been kept alive in the artificial womb for four weeks; long enough to dramatically increase their chances of survival outside the womb.

It may be awhile before you'll see artificial wombs for human use. But perhaps some day, you'll have a grandchild that was delivered at 19 weeks of gestation then grown for four weeks or more in a plastic bag!

Friday, April 28, 2017

Are Vitamin D Supplements Effective in Preventing Disease?

Are you one of the millions of people who are taking vitamin D supplements? People take vitamin D supplements to prevent depression, muscle weakness, cancer, heart disease, and who knows what else. And yet, there is a lack of evidence that vitamin D supplements will prevent any of these conditions.

The trend to test for and treat alleged vitamin D deficiencies took off in 2011 with the publication of a book entitled The Vitamin D Solution - A 3-Step Strategy to Cure Our Most Common Health Problems. The suggestion by the book's author that vitamin D levels of 21-29 ng/ml are insufficient for good health were a bit of a shocker, since blood levels of vitamin D of greater than 20 ng/ml are considered normal.  The book and several studies that seemed to support its thesis led to an increase in vitamin D screening blood tests, and to recommendations by many physicians that their patients consider taking vitamin D supplements.

However, the Institute of Medicine says that there is no evidence that people who have vitamin D levels above 20 ng/ml (i.e. normal vitamin D levels) will benefit from taking additional vitamin D.  In addition, two studies published this year show that vitamin D supplements don't prevent heart attacks and don't protect women against cancer. An ambitious 5-year study is now underway to try to determine once and for all whether vitamin D supplements are of any use in preventing cancer, heart disease, and stroke.

I don't know about you, but I'm taking vitamin D deficiency off my list of things to worry about, at least for now.

Tuesday, April 25, 2017

'Subclinical' Hypothyroidism is Being Over-treated

What was the most prescribed drug in 2016?   If you guessed a blood pressure medication, a cholesterol-lowering drug, insulin for diabetes, or even a painkiller such as oxycodone, you'd have been wrong.  It was levothyroxine, a drug used to treat hypothyroidism. But not all physicians are using this drug correctly; many are using it to treat 'subclinical' hypothyroidism.

Subclinical hypothyroidism is generally defined as a slightly elevated TSH (thyroid-stimulating hormone; indicating perhaps an under-responsive thyroid gland), accompanied by a number of vague and highly subjective symptoms such as tiredness, lack of motivation, and muscle aches and pains. It's called 'subclinical' hypothyroidism because levels of the two thyroid hormones, T3 and T4, are still normal, as opposed to true hypothyroidism in which there is a clear deficiency in these two hormones.

The problem is that many of the physical symptoms of hypothyroidism, such as tiredness and muscle aches and pains, are common complaints in older people.  So if their TSH levels are just a little over the normal level (which also often happens with age), physicians are increasingly putting their older patients on levothyroxine, regardless of what their T3 and T4 levels are.  As a result, fully 15% of older Americans are taking levothyroxine to treat their alleged symptoms.

However, recent evidence shows that other than lowering TSH levels to normal, levothyroxine doesn't have any effect on the actual "symptoms" patients are complaining about - no effect at all.  If this new evidence is correct, physicians could stop prescribing levothyroxine to treat 'subclinical' hypothyroidism entirely.  The proper use of levothyroxine is to treat patients with true hypothyroidism, in which T3 and T4 are demonstrably low.

Monday, April 17, 2017

Lyme Disease is On the Rise

People who live in the Northeast are aware of Lyme disease; a baffling, debilitating, bacterial infection spread by bites from certain types of ticks.  Lyme disease is difficult to treat if not detected and treated early.  The forecast is for an increase in the number of cases of Lyme disease this summer. The reason is an increase in the population of field mice last year; mice, it turns out, are a preferred host of the ticks that spread the disease.

Cases of Lyme disease in the U.S. have tripled in the past 20 years, according to the Centers for Disease Control and Prevention (CDC).  For more on why that is, see the recent article in The New York Times.

How can you prevent becoming infected? Your best defense is to avoid being bitten by ticks.  If you are outside in a tick-infested area, be sure to check yourself carefully for ticks after coming back inside.  Most ticks won't actually bite you in the first 12-24 hours or so, so it pays to get them off of you as soon as possible.

Thursday, April 13, 2017

Updated Prostate Cancer Screening Guidelines

Just five years ago the U.S. Preventive Services Task Force (USPSTF) recommended that men 55-69 should be "discouraged" from having the PSA test to screen for prostate cancer (see this blog, May 27, 2012). At the time, the best evidence was that the risks of having a PSA test slightly outweighed the rewards. That's because the PSA test is not 100% accurate; sometimes it gives false positive results, meaning that the test indicates that prostate cancer might be present when in fact it isn't. According to the USPSTF, these false positive PSA tests were leading to biopsies (the next step in making a diagnosis), radiation, and sometimes even to surgeries for prostate removal, all of which carry some risk.

But just recently the USPSTF reversed course; now it recommends that men aged 55-69 should "have a conversation with their doctor" about the advisability of having the PSA blood test to screen for prostate cancer. Why the apparent about-face? Again, it's based on the best available evidence. The PSA test hasn't gotten any more reliable, but what has changed is what happens after a positive test result. Recent research has showed early, aggressive treatment after a positive PSA test isn't necessary and doesn't increase patient survival. That means that doctors can afford to wait, doing repeated PSA tests for years if necessary before recommending biopsies or treatment. As a result, the risks of having the PSA test (and everything that comes after) have declined to the point that the rewards now slightly outweigh the risks.

As before, the PSA test is not recommended for men over 70 (they're likely to die of something else before they would die of a slow-growing prostate cancer) or for men under 50 (prostate cancer is too rare in younger men for the test to be of much benefit).

Saturday, April 8, 2017

Home Genetic Testing and Risk Assessment Approved by the FDA

Back in 2013, a company called 23andMe (referring to the 23 pairs of human chromosomes) offered a genome testing service that promised to analyze a sample of the DNA in your saliva for over 300 alleles, many of which were associated with increased risks of genetic diseases. At the time, the FDA claimed that providing information about future risk of genetic disease was tantamount to offering medical device, and ordered the company to stop selling the kits for medical purposes (see this blog, Dec. 5, 2013).

For a time thereafter, 23andMe survived by selling its kits for "entertainment", i.e. to provide insight into ancestry for those who were interested. But it kept working on the medical angle. In 2015 the company went back to the FDA and was given approval to provide genetic information regarding allele "carrier" status for 36 genetic conditions, such as cystic fibrosis and sickle cell anemia, as long as the company didn't make any statements about the risks of developing a genetic condition as a result of the alleles (see this blog Nov. 3, 2015).

Still, the company kept working on the goal of being able to provide customers with valid risk assessment data. And apparently they did a pretty good job, for this week the FDA gave 23andMe permission to identify 10 telltale markers of genetic diseases, including Parkinson's disease and late-onset Alzheimer's disease, and provide information about the likelihood that the customer will develop the genetic conditions associated with these markers (my emphasis added). It's a big win for a small company, and a testament to the company's perseverance.

A word of caution, however, before you decide to have your DNA analyzed. You should know that you may not be able to keep the results of your home genetic test private under certain circumstances (see this blog, Mar. 13, 2017).

Sunday, April 2, 2017

A Texting-While-Driving Accident Claims 13 Lives

Here we go again. A lot has been written about the dangers of texting while driving, yet many of us just can't seem to resist the temptation. The death toll continues to climb.

Consider the most recent incident. Local sheriff's offices received several calls that a pickup truck was driving erratically on a two-lane highway west of San Antonio, Texas. One of the callers even recorded video footage of the truck. Although police responded to the calls quickly, they reached the pickup only after it had plowed head-on into a church van, killing 13 people. According to a Fox News report, the 20-year-old driver of the pickup truck (who survived the crash) said "I'm sorry, I'm sorry, I was texting."

Thirteen deaths is a lot to feel sorry for, especially when they could have been avoided so easily. And a lifetime of remorse is only part of what this young man will have to endure; what's the law going to do to him? I do truly feel sorry for him, because I'm sure he had no intention of harming anyone.

What's it going to take to get you to put down your phone while driving?

Tuesday, March 28, 2017

A New Vaccine Against a Diarrhea-Causing Virus

A new vaccine may represent an improvement over older vaccines against a deadly virus that causes severe diarrhea in children. The virus, called rotavirus, kills over 200,000 children under the age of five each year, mostly in Pakistan, India, and the African continent.

Current rotavirus vaccines have two drawbacks; they are only partially effective, and they require refrigeration. The need for refrigerated transport and storage of a vaccine or medicine is a real problem in very poor and very rural environments, where infrastructure is inadequate and even the availability of electricity may be sporadic. The new vaccine, called Rotasiil, is manufactured by an Indian company and was tested in Niger, where it proved to be 67% effective; as good or better other vaccines currently available. It does not need to be refrigerated, it can be delivered orally, and as an added bonus it's expected to be inexpensive, or at least cheaper than other available vaccines.

Over 200,000 childhood deaths a year, and you've probably never even heard of rotavirus! In the U.S., rotavirus infection is rare because vaccination against rotavirus is just part of the normal childhood vaccination schedule; its given as either one or two doses before the age of six months. Just goes to show that there are a lot of pretty nasty bugs out there, and not everyone in the world is equally protected against them.

Friday, March 24, 2017

Using Cellphone Photos for Medical Analyses

There's an app now for taking medical-grade selfies of a sort. Actually, they're selfies of urine dipsticks, useful for diagnosing and monitoring certain diseases and conditions.

Clinical diagnosis of certain diseases and conditions relies on simple dipstick analysis of a sample of urine. Typically, a paper dipstick that changes color when dipped in urine is compared to a color chart to determine the presence or absence of certain substances in the urine, such as glucose, blood, or protein. Diagnosis depends on a physical comparison of the color of the dipstick to a reference color chart.

It would be nice to be able to just take a photo of the dipstick and send it in to a health professional, so that diagnosis could be done remotely without the patient having to go to a clinic. But the problem with photo analysis of a dipstick is that the colors depend critically on lighting conditions and the angle at which the photo is taken. But now an app developed by an Israeli company called Healthy.io has gotten around that problem. First, a photo of the dipstick is taken against a proprietary color card. The app, called Dip.io, then color-corrects the background colors to mimic natural ambient light and reads the dipstick. The company hopes that Dip.io will provide patients and their physicians with an easy and inexpensive way to monitor certain diseases characterized by substances in the urine, such as diabetes (glucose), chronic renal failure and pre-eclampsia of pregnancy (protein), and urinary tract infections (blood).

The ability to standardize photographs for color and size opens up all kinds of possibilities. Take dermatological conditions, for example. If moles on the skin were photographed against a background card displaying objects of various sizes and colors, the results could again be standardized to allow long-distance diagnosis. The barriers to entry into this exciting new development in distance medicine are low (just the development of an app), so we can expect Healthy.io to have healthy competition in the future.

Disclosure: I have no financial interest in Healthy.io, nor do I expect to have one in the future. I'm just interested in new and interesting medical technologies.

Monday, March 13, 2017

Congress May Curtail GINA's Protection of Your Genetic Information

A law passed in 2008 called the Genetic Information Nondiscrimination Act (GINA) prohibits employers and health insurers from requiring you to submit to genetic testing as a condition of employment or to receive health insurance (see this blog, June 2, 2008).  It also prevents employers or health insurers from requiring you to answer questions about any previous DNA tests you may have had.  GINA was designed to prevent discrimination based on genetic information about your future health risks.  (Interestingly, GINA does not apply to life, disability, or long-term care insurance; see this blog, Apr. 17, 2014).

Now a bill introduced in the republication-controlled Congress is attempting to take away the protections written into GINA.  H.R. 1313 would allow employers to ask employees intrusive questions about the employee's health, as well as about the health and any genetic tests they or their family members have undergone in the past.  Although refusing to answer still can't be used against the employee in terms of employment, those who choose not to answer could be required to pay 30-50% more for their company-provided health insurance.  In effect, H.R. 1313 would require employees to choose between privacy of their genetic information and the cost of their health insurance.

By the way, the definition of "family member" used originally in GINA and adopted by H.R. 1313 goes way beyond just parents or children.  It extends to the fourth degree, meaning from great-great-grandparents to great-great-grandchildren, as well as generations of aunts, uncles, and cousins.  H.R. 1313 could potentially expose your extended family's entire genetic history, to the extent that it is known.

I'd be wary of agreeing to any genetic tests if this bill passes. You can't answer what you don't know.

Friday, March 10, 2017

Colorectal Cancer is Increasing in Young Adults

Colorectal cancer is generally considered to be a cancer of older people - so much so that the current recommendation is for colorectal cancer screening (a colonoscopy) every ten years after the age of 50. Most cases of colorectal cancer occur in people over 6O. Overall, the incidence of colorectal cancer has started to decline. However, in recent years there has been a sharp rise in colorectal cancer in the young. According to a report published in the Journal of the National Cancer Institute, adults born around 1990 (now in their 20s) have twice the risk of colon cancer and four times the risk of rectal cancer as a person who was born around 1950 when they were in their 20s.

The reason for this startling increase in risk for young people is not known. To be fair, the actual risk of colorectal cancer for persons in their 20s is still very low; about 1 case/yr. (per 100,000 population), compared to the over 50 cases/yr for persons over 60.  If you're young, it's probably not worth worrying about.

However, the trend toward an increase in risk for the young is of concern to scientists, if only because we don't understand why it is happening when overall risk across all age groups is declining.  It's worth keeping an eye on.  At the very least, physicians should not rule out the possibility of colorectal cancer in their younger patients.  Perhaps persons who have a family history of colorectal cancer should consider being screened before age 50.

Tuesday, March 7, 2017

Bird Flu is On the Rise Again

A deadly type of bird flu known to be transmissible to humans, called H7N9, seems to be breaking out again this flu season in China. H7N9 has caused only modest outbreaks since 2013, the year it was first identified (see this blog, Apr. 17, 2013). The intensity of yearly H7N9 outbreaks peaked in 2014 and then seemed to decline in 2015 and 2016, leading some health officials to think that the worst was over. Not so, it seems. The current 2017 outbreak of H7N9 (which began in October, the typical start of the winter flu season) is the worst outbreak yet. According to the World Health Association (WHO), more than a third of all cases of H7N9 flu ever recorded have occurred during this year's outbreak, and flu season isn't over.

H7N9 bird flu is not easily transmitted from birds to humans, but it is quite virulent. The death rate from confirmed H7N9 infections in humans is nearly 40%. So far, there are no confirmed cases of human-to-human transmission. Health officials worry that if/when the virus mutates in a way that makes it easily transmissible between humans, we could face a worldwide pandemic.

For now, H7N9 outbreaks have been confined to China, where close contact with poultry is much more common than it is in this country. Are we prepared for a H7N9 bird flu pandemic? The short answer is "no". At the moment there is no vaccine against it. Let's hope that a change to human-to-human transmission of H7N9 doesn't develop anytime soon.

Thursday, March 2, 2017

Supreme Court Nominee Gorsuch Opposes Death With Dignity Laws

Judge Neil Gorsuch, president Trump's nominee to the U.S. Supreme Court, is not a supporter of death with dignity (also called medical aid in dying) laws. In his 2009 book entitled The Future of Assisted Suicide and Euthanasia he defends his position, writing "...all human beings are intrinsically valuable and the intentional taking of human life by private persons is always wrong."

Five states (Oregon, Washington, Vermont, Colorado, and California) currently have death with dignity laws, and several others are considering them. In general these laws allow a person to terminate his/her own life under certain very narrow circumstances, which generally include the presence of a terminal illness, adequate counseling, and the consent of a physician. The Supreme Court has not yet considered a case involving these laws, so for now the states can make their own decisions.

Not every state is likely to pass death with dignity laws; indeed, some state's legislatures or legal counsels actively oppose them. The deputy solicitor general of the state of Wisconsin, for one, is already thinking about strategies for opposing death with dignity laws, should one ever be challenged in the federal courts.

The first challenge to a death with dignity law in the Supreme Court is likely to have a friend in Justice Gorsuch, should he be confirmed by the U.S. Senate. Just sayin'.

Monday, February 27, 2017

Microdosing With LSD to Treat Depression?

There seems to be a lot interest these days in the possible use of hallucinogens for medical purposes. Last month I reported that in a clinical study, the hallucinogen found in "magic mushrooms" seemed to reduce the symptoms of depression and anxiety, specifically in cancer patients (see this blog, Jan. 9, 2017).  Now it appears that very small doses of another potent hallucinogen, lysergic acid (LSD), are being used by some people as a self-cure for more common forms of anxiety and depression.

It's called "microdosing".  The trend started with the publication of the 2011 book, The Psychedelic Explorer's guide: Safe, Therapeutic, and Sacred Journeys.  More recently, microdosing moved into the mainstream, more or less, with the publication of one woman's memoir, entitled A Really Good Day: How Microdosing Made a Mega Difference in My Mood, My Marriage, and My Life.

Wow, who wouldn't want a better mood, marriage, and life!?  To be fair, microdosing with halucinogens might actually have some positive effects.  But skeptics such as Richard Friedman would say that it's not a good idea to self-treat depression with psychogenic drugs just because someone wrote a self-help book about it.  Microdosing with hallucinogens is untested; it's not even in the preliminary clinical research stage.  Anyone trying it is taking unknown risks.

Wednesday, February 22, 2017

First Vaping, Now "Dripping"

A study by researchers at Yale University reveals that about a quarter of all Connecticut teenagers who have tried vaping have circumvented e-cigarettes' design to deliver a stronger and more potent nicotine experience.  It's called "dripping"; instead of allowing the e-cigarette's wick to deliver a controlled amount of liquid to the cigarette's coils, the coil is exposed so that nicotine liquid can be dripped directly onto the hot coils, producing a much heavier nicotine vapor cloud.

Regulators aren't sure how to respond to this recent trend.  Although e-cigarettes certainly aren't as harmful as cigarettes, their long-term harm (if any) is still not known simply because they haven't been around long enough.  The concept of e-cigarettes has been around since the 1930s, but the first commercially successful product wasn't created until 2003.  For a complete timeline of the development and regulation of e-cigarettes, see this file.  I can't confirm or deny the accuracy of the timeline, but the file was compiled by a group called Consumer Advocates for Smoke-Free Alternatives Association, so please be aware of possible bias.

Wednesday, February 15, 2017

Gaining Ground on Clostridium difficile Infections

One of the most dangerous of all gut bacteria is a bacterium called Clostridium difficile.  C. difficile can cause diarrhea so severe that it can lead to death, especially in older patients in hospitals and nursing homes, in whom it is most common.  To make matters worse, it is difficult to treat because it is resistant to most antibiotics.  Although it is present in most people, its population is normally kept in check by the presence of other "good" bacteria, which tend to out-compete it.  But when nearly all of a person's gut bacteria are wiped out, for example when the person is given antibiotics, C. difficile can reproduce explosively, overwhelming the body's defenses.

Although C. difficile was first identified over 80 years ago, it wasn't until this century, when a strain of C. difficile developed resistance to most antibiotics, that the bacterium became a serious clinical problem.  In a 2015 study published in the New England Journal of Medicine, the Centers for Disease Control and Prevention (CDC) reported that in 2011, C. difficile infections caused about 15,000 deaths directly and contributed indirectly to another 14,000 deaths.

But now health officials are seeing signs that C. difficile infections may be on the decline.  One of the key factors may be our more enlightened use of antibiotics; i.e., only when truly needed.  By reducing the indiscriminate use of antibiotics, especially in hospitals and nursing homes, there have been fewer opportunities for C. difficile to gain a foothold.  But there are other signs of hope, too.  Several vaccines are in the works, and Merck has a new (and expensive) drug called Zinplava that is at partially effective at reducing recurrent infections.  Even fecal transplants (to reintroduce competing bacteria; see this blog, Feb. 23, 2014) seem to help, though these are still just in the experimental stage.

Progress is being made, though sometimes it seems slow.  All we can do is keep trying.

Saturday, February 11, 2017

Improving the Odds of Successful In Vitro Fertilization

During a normal monthly reproductive cycle, the endometrial lining of the uterus undergoes a series of changes that make it receptive to the possible arrival and successful implantation of an early-stage embryo.  Endometrial receptivity only lasts about 12 hours; under natural conditions it coincides with the time that the early-stage embryo would be expected to arrive at the uterus, if in fact an egg was fertilized that month.  It all just happens naturally, without any thought on our part.

For infertile couples who opt for in vitro fertilization (IVF) in an attempt to become pregnant, timing can be critical.  If the embryo is introduced into the uterus at a time when the uterus is not receptive, the whole process can end in failure.  An IVF procedure can cost tens of thousands of dollars, and its not unheard of for couples to try multiple times without success and without knowing why.  One possible reason for multiple failures is that the embryo may not have been introduced into the uterus at precisely the right time.  The 12-hour window of maximum receptivity can occur on different days of the cycle in different women, and in the past there was no way to determine it.

But now there's a test to determine the precise moment of maximum endometrial receptivity.  It's called the endometrial receptivity array (ERA) test.  The test works by analyzing the genetic expression of several hundred of the genes known to be involved in the buildup of the endometrium in preparation for implantation.  The period of maximum expression of these genes coincides with the best time for embryo implantation.  The test has dramatically improved the odds of a pregnancy for couples who had previously experienced multiple IVF failures.

Tuesday, February 7, 2017

An Experimental Alzheimer's Drug Fails in a Clinical Trial

A potentially promising drug for the prevention of Alzheimer's disease has failed in a key clinical trial, according to Eli Lilly, the drug's developer. In a study involving more than 2,000 patients with early signs of dementia, the drug, known as solanezumab, failed to prevent the advancement of the cognitive impairment that accompanies dementia and that leads ultimately to Alzheimer's disease.

The results were disappointing, but not all that surprising. So far, no drug has been able to prevent the progression of dementia once it has started. Researchers are reluctantly coming to the conclusion that by the time dementia first becomes apparent, it is already too late to affect the future course of Alzheimer's disease.

Whether solanezumab could prevent the development of dementia if it were given before the first signs of dementia is not known. Sadly, it may never be known. That's because it would be prohibitively expensive to conduct a drug study involving tens of thousands of seemingly normal people, in the hope of observing an effect on the few people among them that will ultimately develop dementia.

So we're at an impasse at the moment. There are several drugs on the market that can reduce (at least temporarily) the symptoms of the dementia associated with Alzheimer's disease, but there are no drugs that can prevent the slow progression of the disease. There aren't even any on the horizon, apparently. Don't expect progress any time soon.

Friday, February 3, 2017

Many Primate Species Face Extinction

Our closest living relatives in the animal kingdom, the primates, are in trouble. According to a comprehensive review of primate populations around the world by some 31 scientists from 11 countries, nearly 60% of all primate species are in danger of extinction, and many of the others are in decline. That includes every species of apes and nearly all species of lemurs. The one primate species that still appears to be doing extremely well is humans.

The causes are multiple and predictable. Reduction in habitat due to an expanding human population, changes in primate's habitat due to logging, agriculture, and mining, predation (hunting) by humans, and even climate change are all thought to be contributing factors.

Unfortunately, there aren't any easy solutions on the horizon. Unless action is taken soon, it becomes increasingly likely that some of our primate relatives will disappear from planet Earth, if not within the next few decades, most certainly within the next few centuries. And that would be sad.

Friday, January 27, 2017

New Guidelines for the Prevention of Peanut Allergy

An expert panel of scientists meeting under the sponsorship of the National Institute of Allergy and Infectious Diseases has issued new guidelines for the prevention of peanut allergies in young children. The guidelines draw on findings published last year (see this blog, Mar. 9, 2015) which showed that adding peanut proteins to the diet of young children at risk for developing allergies significantly reduced the chances of those children developing peanut allergies by age five. The new guidelines are that infants can be fed peanut-containing foods at any age; as early as they begin taking solid food, in fact.

Some parents are skeptical, and a few are even angry. That's because the previous guidelines were to withhold peanuts from young children in the hope that sensitivity to peanuts could be avoided. According to these parents, this reversal of the guidelines is just more evidence that scientists (and their recommendations) shouldn't be trusted.

But the reality is that we try to make rational choices based on whatever information we have at the time. So when new and better information becomes available (such as the data published last year), we should look carefully at it and change our view, if warranted. In a nutshell (no pun intended) that is what has happened with the peanut recommendations.

Tuesday, January 24, 2017

2016 was the Hottest Year on Record

2016 was the hottest year on record and the third consecutive year of record temperatures, according to climate scientists.   Furthermore, the rate of temperature change seems to be accelerating.

Nearly all climate models conclude that the most likely cause of global warming is rising levels of atmospheric CO2 levels brought about by the burning of fossil fuels.  And yet, so far not much has been done about it.  The problem (and perhaps the reason that climate deniers continue to deny that global warming is even happening) is that curbing future increases in CO2 will not be easy or cheap as long as we continue to depend on fossil fuels for most of our energy needs.

And so Earth will probably continue to warm up.  Sigh.

Sunday, January 15, 2017

Should "Gene Editing" be Regulated?

The generally accepted definition if a GMO (genetically modified organism) is an organism whose genome has been modified by the addition of one or more genes from another species.  Most genetically modified corn, for example, has been modified by the addition of genes from certain bacteria, with the goal of giving the corn either resistance to insect pests or resistance to a common herbicide.  Not everyone thinks that GMOs are a good idea, and there have been numerous efforts (some successful, some not) to block their development and widespread use.

Now for a new but related question; how should we feel about "gene editing"; the simple removal of existing genes from an organism, without the addition of foreign genes?  It's now possible, due to a recently developed technique (called Crispr) for selectively snipping genes out of DNA at selected locations.  Crispr is already being used to produce gene-edited plants of interest, such as potatoes or mushrooms that don't turn brown and soybeans with healthier fatty acids.

Last year Congress passed a law requiring that foods containing GMO ingredients must be labeled as such.  However, that labeling requirement apparently doesn't extend to plants that are just gene-edited because currently they fall outside the regulatory authority of the federal agencies that oversee GMOs, such as the Agriculture Department and the Food and Drug Administration.

It'll be interesting to see whether the regulatory agencies ever decide to examine and/or regulate gene editing.

Friday, January 13, 2017

Does Prevagen Improve Memory?

You've seen the commercials for Prevagen, right? It's a dietary supplement containing a protein derived from jellyfish that (according to the manufacturer) "improves memory and reduces common cognitive problems associated with aging." Trouble is, those claims are bogus, according to both the Federal Trade Commission (FTC) and the New York Attorney General's office. This week the two agencies sued Prevagen's manufacturer, Quincy Bioscience for making false and misleading claims, most notably the claim that Prevagen has been "clinically proven" to work. According to the complaint, the experiments undertaken to prove Prevagen's effectiveness were scientifically invalid because they did not show that Prevagen worked any better than a placebo.

No big deal, you say? Well, if you give people memory tests over time, you'd expect some improvement just from test familiarity alone. That's why it's so important to compare the experimental (Prevagen) group to a control group (a group given a fake pill, or placebo), using valid statistical methods.

Prevagen can cost upwards of $60 for a 30-pill bottle. According to the FTC, about $165 million a year is spent on the supplement. That's a lot for an untested cure.

Quincy Bioscience has responded to the lawsuit with a statement that says, in part, that Prevagen hasn't been shown to harm anyone (which is beside the point), and that "hundreds of thousands" of people tell them that Prevagen works and improves their lives. The latter statement, of course, is unscientific and unverifiable.

Monday, January 9, 2017

A Hallucinogen Reduces Anxiety and Depression in Cancer Patients

Two well designed studies published simultaneously by research teams at New York University and Johns Hopkins University have both come to the same conclusion: that a single dose of a powerful hallucinogen reduces anxiety and depression in patients with life-threatening cancers. The hallucinogen, known as psilocybin, is the active ingredient in "magic mushrooms". Nearly 80% of the patients reported feeling better following their hallucinogenic experience. The most striking finding was that they felt better for a long time - more than six months, in fact.

The federal government doesn't allow the use of public funds for research into the possible therapeutic uses of criminalized drugs. However, the research itself isn't banned. The present studies were funded largely from private sources after careful review by university research panels and federal regulators.

No one is suggesting that psilocybin should be made widely available to cancer patients. Nor is anyone suggesting (yet) that psilocybin should be used to treat general anxiety and depression. Still, the very long-lasting effect on anxiety and depression of a single hallucinogenic dose of psilocybin is intriguing. We need to know more about how this hallucinogen works. What if, for example a closely related drug could be found that reduces anxiety and depression, without the initial hallucinogenic effect?  Now, that would be a blockbuster drug.

Thursday, January 5, 2017

Taking Fish Oils During Late Pregnancy Reduces Childhood Asthma

A Danish study reports that children whose mothers who took high doses of fish oils during the last three months of pregnancy were about 30% less likely to develop asthma by age three.  16.9% of children of mothers who took fish-oil capsules developed asthma by age three, compared to 23.7% of children of mothers who took placebo capsules containing olive oil.

What on earth prompted the researchers to even think of such an experiment?  It turns out that there was some logic behind it.   Two relevant facts are; 1) chronic inflammation in the lungs and airways contribute to the development of asthma, and 2) the fatty acids in fish oils are known to reduce inflammation.  Put these two together, and the experiment seemed like a good idea.

The researchers say it's too early to recommend that all pregnant women take fish-oil capsules during pregnancy.  For one thing, the doses used in this experiment were high; 2.4 grams 0f fish-oil per day, or about 15-20 times the amount found in a normal U.S. diet.  It's not known whether lower doses might be just as effective.  Nor is it known whether the results would be better (or worse) if the women had taken the fish oils throughout pregnancy, instead of just in the last trimester.

Also, consider this: the beneficial effects of fish-oils on asthma were demonstrated only because the researchers were looking for an effect on asthma as their experimental endpoint.  Could there be negative side effects of high doses of fish oils that weren't found because they weren't looked-for?  I'm not saying that there are; I'm just making the point that it's hard to prove complete safety of a drug or treatment because there are always a lot of possibilities to test.  You won't find what you don't look for.

In the long run, the real importance of the current findings may be that they encourage further research leading to a much more targeted approach to preventing asthma than just ingesting large doses of fish oils.  It's a start.