Sunday, July 20, 2014

The Cost of Not Understanding Risk

Many women believe that annual or biennial mammograms will dramatically reduce the risk of dying of breast cancer. Statistics prove them wrong, however. For more on risk versus women’s beliefs about risk when it comes to mammograms, see the New York Times article entitled “Universal Mammograms Shows We Don’t Understand Risk”.

You might think that understanding risk not that important. Think again. Screening all women over the age of 50 for breast cancer every other year is expensive. If it’s not going to save a significant number of lives (i.e. isn’t cost/effective), perhaps that money could be better spent on something that does have a significant effect on women’s health.

It’s not my intent to pick just on women here - men believe that screening for prostate cancer saves lots of lives, too, but it doesn’t. I’m also not arguing against screening tests in general, or against mammograms or prostate tests for individuals at high risk. Screening tests have a valuable place in our health care system. Let’s just use them wisely.

Sunday, July 13, 2014

The Economic Impact of Climate Change

One of the problems with any discussion of climate change these days is that there is very little good information about the potential effects of climate change on the economy. Without such information, how can we decide what actions to take to slow or mitigate climate change’s economic impacts? Some politicians continue to deny that climate change even exists. I think its because acknowledging the problem would mean that we’d have to do something about it, and any fix is going to cost a lot of money. So we continue to avoid dealing with climate change….

In an effort to shed some light on the potential economic impacts of climate change, an independent, non-partisan group of business people and politicians has prepared an economic risk analysis of climate change. The group examined all of the current research findings available. The final document, called the Risky Business report, describes some of the potential impacts of climate change, region by region.

A key takeaway message from the report is that whether its an increase in sea level, changes in temperature or rainfall, or increased tornadoes/hurricanes, different regions of the country are going to be affected differently. You can access the Risky Business report here to see how your region of the country is likely to be affected.

Wednesday, July 9, 2014

The One-Dollar Microscope

A microscope that costs less than a dollar?  The Foldscope is made primarily of paper, plus a sapphire ball lens, a LED light source, and a small button battery.  It can be easily folded (assembled) into a working 2000-x microscope within minutes.  Although not as versatile as a microscope costing hundreds of dollars, the Foldscope is good enough that one can see individual cells in a sample, and even identify some bacteria and tropical diseases such as malaria and schistosomiasis.

The Foldscope was designed by scientists at Stanford University.   It is currently being tested by the first 10,000 persons who signed up to receive one.   From their many experiences, the volunteers will also help develop a crowd-sourced microscopy manual.  The goal of the scientists who developed the Foldscope was to create a simple cost-effective tool that could be used to stimulate curiosity in science and biology.  It may also have applications in global health.

You can’t buy a Foldscope just yet.  But at only a dollar apiece it may not be long before they are standard issue in most schools, and also in health clinics in poor countries.

Sunday, July 6, 2014

Inhalable Insulin, Round Three

Last month the FDA approved yet another inhalable insulin product for use in controlling blood sugar in Type 1 and Type 2 diabetics.   The new product (called Afreeza) delivers powdered insulin via an inhaler similar to those used by asthmatics.  Designed to be used before each meal, Afreeza is apparently one of the most rapidly acting insulin products available.

It’ll be interesting to see whether anyone cares any more this time than they did last time.  Inhalable insulin products have been attempted twice before, and both times the products were spectacular failures.   Pfizer was the first pharmaceutical company to bring an inhalable insulin product (called Exubera) to market, back in 2006.   The company quit making Exubera after just a year due to poor sales.  Shortly thereafter, Eli Lilly halted the development of its own inhalable insulin product before it even came to market (see this blog March 10, 2008).

But even in the face of these spectacular failures, it’s been hard for pharmaceutical companies to give up on the idea.  The market for diabetes treatment products is huge – there are nearly 30 million diabetics in the U.S. alone.   Even a small part of the sales of diabetic products would be a huge boost to the bottom line of most pharmaceutical companies.   MannKind, the small company that spent nearly $2 billion developing Afreeza over the last decade, thinks that Afreeza will prove to be successful where others failed.  But don’t hold your breath.   Pfizer’s experience was that diabetics really didn’t mind their syringes and small needles all that much.  Whether an inhalable insulin product ever gains widespread market acceptance may boil down to price.

Wednesday, July 2, 2014

Alicia Silverstone is Clueless (Again)

The latest actress to speak out against childhood vaccines is Alicia Silverstone, best known for the 1995 hit movie, “Clueless”. The actress had a baby several years ago, and apparently she thinks that qualifies her to give advice to future mothers. In her new book entitled “The Kind Mama: A Simple Guide to Supercharged Fertility, a Radiant Pregnancy, a Sweeter Birth, and a Healthier, More Beautiful Beginning”, the actress makes unsubstantiated claims about natural plant-based diets; claims tampons may cause infertility; and questions the safety of vaccines.

Regarding the schedule of childhood vaccines, she reports anecdotal concerns by other parents because she can’t find the scientific evidence to support her claim. She writes, “While there has not been a conclusive study of the negative effects of such a rigorous one-size-fits-all, shoot-‘em-up schedule, there is increasing anecdotal evidence from doctors who have gotten distressed phone calls from parents claiming their child was ‘never the same’ after receiving a vaccine. And I personally have friends whose babies were drastically affected in this way.”

She’s entitled to say whatever she wants, of course. The rest of us shouldn’t listen. Numerous scientific studies have failed to establish any link between vaccines and certain conditions such as autism, because there isn’t any link. Whether or not to vaccinate children shouldn’t still be an issue.

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.