Thursday, May 26, 2011

Melatonin in Brownies

Melatonin, a hormone and over-the-counter dietary supplement that supposedly promotes sleep and was once popular as a cure for jet lag, is now being sold in baked goods as an all-natural antidote to stress and sleep deprivation. But there’s a catch; since melatonin has not been approved as a food additive, the entire baked good containing melatonin has to be marketed as a “dietary supplement”. Indeed, the makers actually label them (in small print) “not for food use”.

Really? Products with names like Mary J’s relaxation brownies and Lulla Pies are not meant as food? Calling them dietary supplements is just an obvious way around the legal requirement that food additives must be approved by the Food and Drug Administration (FDA).

The FDA may not allow the sale of these products to continue in the long run, but the fact is that it generally takes a long time for the FDA to act. In the meantime you can buy these products at your local store. Just don’t plan on driving or operating heavy machinery after eating (uh, taking) this “dietary supplement”.

Sunday, May 22, 2011

Stem cells for Joint Injuries

Stem cells are being used to treat some professional athletes with joint injuries, according to an article in the New York Times. In the still highly experimental procedure, stem cells harvested from the patient’s own bone marrow and fat are injected directly into the patient’s injured shoulder or elbow to try to speed up the repair process. New York Yankees pitcher Bartolo Colon had the procedure done in the Dominican Republic last year, and now he’s back in the Yankee’s starting line-up. Just a year ago his professional career appeared to be over; he sat out the entire 2010 season following elbow surgery.

Mr. Colon’s recovery is anecdotal evidence that the procedure may work. On the other hand, Mr. Colon’s recovery could have been an anomaly or may have been unrelated to the treatment. Clinical trials are now needed to determine whether the procedure would actually benefit most patients. It’s not against the law to try an experimental procedure such as this on patients who are willing to pay for it. But before the procedure is put into widespread general practice, it would be nice to know whether it truly is effective.

Reference: Kovaleski, Serge F. Pitcher's Treatment Draws Scrutiny. The New York Times online, May 11, 2011.

Wednesday, May 18, 2011

Recombinant Factor VIIa for Bleeding?

Recombinant Factor VIIa (rFVIIa) is a potent blood coagulating agent that is officially approved for use only in hemophiliacs. However, a recent study of over twelve thousand patients who received rFVIIa in U.S. hospitals revealed that by 2008, 97% of the in-hospital use of rFVIIa was “off-label” (meaning for uses other than in hemophiliacs.) The most common uses were to reduce bleeding in patients with severe trauma or intracranial hemorrhage, or during cardiac surgery, liver transplantation, or prostatectomy.

U.S. law allows physicians to use drugs for off-label purposes because of a deeply-held belief that only the physician and the patient can determine what is best for each patient. This would make perfect sense if the drug really worked for these off-label purposes. But a review of the available literature (by some of the same authors) reveals that rFVIIa does not reduce mortality when used for any of five off-label uses described above.

Physicians who used rFVIIa off-label in the past were not necessarily wrong to use the drug, of course, because up until now they didn’t have the full information. But now that they do know (or at least should), one would hope that they would examine the need for rFVIIa more closely, especially since the drug costs about $10,000 per dose.

Sunday, May 15, 2011

Antibiotic-Resistant Bacteria in Drinking Water

A bacterial gene associated with resistance to antibiotics is turning up in water samples in New Delhi, India, including two of 50 public drinking-water samples and more than a quarter of all water samples drawn from water pools in streets or small streams.

Even more concerning is that the gene was identified in 11 different species of bacteria in which it had not been reported previously. What this means is that antibiotic-resistant bacteria typically found only in the human gut (such as E. coli) may be passing the gene on to other species of bacteria. Whether bacterial gene transfer is occurring in the human gut or after the resistant E. coli are released into the water supply isn’t certain at this point. But it does point to the development of widespread bacterial resistance to antibiotics through bacterial gene exchange, perhaps even in the environment.

The only good news here is that the researchers did not find the bacterial gene (yet!) in wastewater supplies in Cardiff, U.K. But it may only be a matter of time.

Wednesday, May 11, 2011

The “Telomere Test” for Aging

Telomeres are disposable non-coding regions of DNA at the tail end of each chromosome. Every time a cell divides and its chromosomes are replicated, a small piece of each telomere is removed. That’s because replication stops just short of the end of the original strand because of the need for a primer sequence on each developing new strand. This natural erosion of the telomeres is thought to play a key role in the aging process. Once the telomeres are worn away by repetitive cell divisions, according to at least one current theory of aging, the cell may begin to lose pieces of functional genes with each additional cell division. Eventually the loss of genes either causes the cell to stop dividing or the cell loses some of its normal function.

Now, two commercial companies (one in the U.S., one in Spain) are offering to measure the length of your telomeres - for a price, of course. According to a news report, the companies are promoting the idea that the length of your telomeres may be predictive of how fast you will age, and perhaps even predictive of your risk of developing chronic diseases. Long telomeres for your age? - you’re lucky, you may live a long life. Short telomeres? - perhaps you’d better change your lifestyle or begin looking at ways to reduce your risk of chronic diseases while there’s still time!

Pardon my skepticism, but it sounds a bit like having your fortune told. Spend your money if you wish, but don’t count on learning anything very meaningful just yet from measurements of your telomere’s lengths.

Thursday, May 5, 2011

Asthma is On the Rise

The overall prevalence of asthma increased by 12% between 2001 and 2009, according to a press report released by the Centers for Disease Control and Prevention (CDC) this week. Nearly one in 10 children and one in 12 U.S. adults now has asthma. The most significant rise in asthma in recent years has been among black children.

Asthma is a chronic condition characterized by periodic attacks of chest tightness, coughing, wheezing, and breathlessness. Asthma attacks seem to be triggered by respiratory environmental cues or illness, such as tobacco smoke, air pollution, mold, and colds and flu. It is not particularly deadly and there are prescription medicines available to control most of the symptoms of an attack. Nevertheless, the impact of the disease in terms of medical expenses and lost days from school and work is huge.

Scientists do not have an answer yet for why the incidence of asthma is going up so rapidly. Read more about this puzzling disease in a CDC Vitalsigns report and in the CDC press report.

Monday, May 2, 2011

Stem Cell Research STILL Allowed (Barely)

A three-judge panel of the U.S. Court of Appeals ruled last week that government-funded researchers may use human stem cell lines derived from human embryos before a law apparently intended to ban such research went into effect. (For more on this issue, see blog posts dated Sept. 1 and 13, 2010). The panel ruled that because the language of the law banning research on cells derived from human embryos is written in the present tense, “it does not extend to past actions.”

Surely this will not be the end of it. It sounds like linguistic hair-splitting, even to me. Given that the 3-judge panel was split 2-1 on the issue, the ruling will probably be appealed to the entire Court of Appeals.

In the long run the only real solution may be for Congress to draft unambiguous legislation that makes it clear once and for all under what circumstances, if any, stem cells derived from human embryos may be used. And that will depend on whether either side in this issue can muster the necessary votes.

Stay tuned.