Wednesday, June 25, 2014

Childhood Vaccination Policy Challenged in Court

How do we balance the rights of an child to attend school against the need to protect society from disease?   In New York City, children must be vaccinated against certain vaccine-preventable diseases in order to attend school, unless the child has been granted an exemption on either medical or religious grounds.  The vaccination requirement is intended to protect society from disease; the exemption allows for the rights of an individual under certain special circumstances.  So far, so good.  But there's a catch...

To protect both the unvaccinated child and society as a whole from disease, New York City added an additional feature to its vaccination policy.   In New York City, unvaccinated children can be barred from school whenever another child at the school has a vaccine-preventable disease.  The policy that their child can be barred from school, even if only temporarily, does not sit well with some parents of unvaccinated children.  The parents of two unvaccinated children sued the city, arguing that barring unvaccinated children from school violates their rights under the 14th amendment to the U.S. constitution.  The 14th amendment, as you probably know, guarantees all citizens equal protection under the law.  But does that include the right of an unvaccinated child to attend school, even when it puts themselves and others at risk?

The case is wending its way through the courts.  Just this month a judge of the Federal District Court in Brooklyn ruled in favor of the school system, arguing that there’s nothing in the constitution that speaks to the issue of religion-based exemptions from vaccinations.   This case will almost certainly be appealed.

Saturday, June 21, 2014

An Anti-aging Blood Protein

A blood protein called Growth Differentiation Factor 11 (GDF11) is one of the factors that keeps tissues and organs youthful.   According to research described in a New York Times article, GDF11 stimulates stem cells within tissues, promoting tissue growth and regeneration.

Not surprisingly, GDF11 is abundant in young animals, but less abundant in older animals.   But here’s the really interesting part; transfusing old mice with the blood of younger animals or giving them GDF11 appears to reverse some of the effects of aging, at least in mice.

That last finding has caught the public’s eye.   People are already asking how to get the stuff on the Internet so they can use it on themselves to try to reverse some of the effects of aging.  From an individual’s perspective that may seem like a good idea (who wouldn’t want to live longer and feel younger?)   But is it really such a good idea?

From a evolutionary biologist’s perspective, it makes sense that GDF11 is found in higher concentrations in the young than the old.  Tissues and organs are still growing and differentiating in the young, so you need the stuff.  But after reproductive age, GDF11’s importance declines.   Aging and death are just a normal part of the life cycle.   In fact, it appears that we’re programmed in our genes to age and die once we are safely past reproductive age.  Yes, we might be able to turn back the clock a little in an individual, but there may be a hidden risk; by encouraging stem cells to divide and differentiate we’d probably be increasing the risk of cancer cell as well.

A basic understanding of how GDF11 regulates normal cell growth and differentiation is certainly of interest.   It may even lead to treatments for specific disorders, such as muscle wasting disorders or Alzheimer’s disease.   But it’s highly unlikely that GDF11 will prove be the magic elixir that can turn back the clock on aging.   There’s undoubtedly a lot more to aging than the slow decline in the concentration of a single blood protein.

Sunday, June 15, 2014

Saving Trauma Patients with Ice-Cold Saline?

According to a New York Times article, surgeons at the University of Pittsburgh Medical Center have been given approval to begin a unique clinical trial on certain trauma patients. In severe trauma patients, for example those with knife or gunshot wounds who have already lost so much blood that their heartbeat has ceased, the surgeons will rapidly replace the patient’s blood with ice-cold salt water before undertaking life-saving surgery.

Cooling the blood is routinely used to stop the heart before open-heart surgery. Lowering the body’s temperature lowers its metabolic rate, slowing the onset of tissue death and thus buying surgeons precious time. But replacing a patient’s blood entirely with ice-cold salt water is new. At such cold temperatures the patients will be devoid of brain activity, and thus the patient will appear to be dead.

Because of the unforeseen nature of their trauma, the patients in this study will not be in a position to give their informed consent. Nevertheless, the clinical trial apparently has been approved by whatever ethics committees needed to sign off on it. Presumably there is little to be lost, and everything to be gained, by at least giving it a try.

It’ll be interesting to hear the patients’ experiences of being “brought back” from a state of no brain activity.

Sunday, June 8, 2014

Sunburns, Teenagers, and Melanoma

A study of over 100,000 U.S. Caucasian women who were followed for 20 years confirms what we’ve long suspected; that too many sunburns early in life increases one’s risk of melanoma, the deadliest form of skin cancer. The study, published recently in Cancer Epidemiology, Biomarkers and Prevention, showed that women who reported having had at least five blistering sunburns during their teenage years had almost a 3-fold greater risk of developing a melanoma over the next 20 years, compared to women who never were sunburned in their teenage years.

Interestingly, the same did not hold true for older women who routinely exposed themselves to high amounts of ultraviolet radiation. Although their risks of several other types of less deadly skin cancers were increased by increased exposure to ultraviolet radiation, the risk of melanoma did not increase significantly.

Bottom line; it is particularly important that children and teenagers should be protected from sunburns. Skin damage early in life sets the stage for melanoma, and nobody needs that when protecting yourself and your children is so easy these days.

Friday, June 6, 2014

A New Antibiotic for Use Against MRSA

A new antibiotic still under development that may offer the best defense yet against the flesh-eating bacteria called methicillin-resistant Staphyllococcus aureus (MRSA).  It's called oritavancin.  In recent tests, just a single dose of oritavancin proved just as effective against MRSA as a full 10-day course of intravenous vancomycin, the current best treatment for MRSA.  That means that with oritavancin, a patient with MRSA could be given just a single treatment in an outpatient setting, without any need for hospitalization.  In contrast, treatment with vancomycin usually requires a lengthy hospital stay.  The cost savings in hospitalization alone would be huge.  But with that potential cost savings in mind, it’s likely that the drug’s manufacturer will charge a lot for oritavancin.

One downside is that when a patient is treated with a single dose of a drug and sent home, doctors have less oversight over whether the drug is working or not.  A protocol may need to be developed in which someone checks on the patient over the first few days after treatment.

The FDA is likely to approve oritavancin by this Fall under a program that fast-tracks promising new drugs.

Tuesday, June 3, 2014

Pregnant Women Have More Auto Accidents

According to a new study of more than half a million pregnant Canadian women, pregnancy is a risk factor for having an auto accident. Overall, women are 42% more likely to have a serious auto accident during pregnancy than before pregnancy.

Is it because pregnant women become distracted when the baby kicks? No, because the increased risk of an auto accident peaks in the fourth month of pregnancy, before the fetus is kicking. After the fourth month of pregnancy the risk declines each month until childbirth. And it doesn’t seem to matter whether it’s a first pregnancy or a subsequent one; the increased risk returns with each pregnancy.

It’s an interesting observation, but I’m not sure what to make of it. It does not appear that women have a tendency to take more risks during pregnancy. Their use of tobacco and alcohol declines during pregnancy, indicating a conscious tendency to reduce risky behaviors wherever possible.

Fortunately, no one is suggesting that pregnant women shouldn’t drive. At their very worst, pregnant women still have fewer accidents than men of the same age!