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.

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.