Saturday, April 25, 2015

The FTC Sues Two Marketers of Melanoma Detection Apps

The Federal Trade Commission (FTC), the federal agency whose mission is to protect consumers from misleading or false advertising, filed a lawsuit and reached a settlement with the marketers of two smartphone apps who claimed that their apps could calculate the risk of a mole being a melanoma. According to the FTC, that's akin to offering medical advice. According to the FTC, the companies cannot offer medical advice "unless the representation is truthful, not misleading, and supported by competent and reliable scientific evidence in the form of human clinical testing" of the device.

This raises an interesting question. Who (which government agency) is responsible for oversight of cellphone apps that appear to cross the line by offering medical advice? Are cellphone apps communication devices that should be regulated by the FTC (as was done in this case), or in a health-related context should they be called medical devices, and therefore regulated by the Food and Drug Administration (FDA)? At the moment no federal regulatory agency is clearly responsible, and so the first apps have gone largely unregulated. Until the FTC stepped in, that is.

Saturday, April 18, 2015

California Legislature Debates Vaccination Bill

The California legislature is considering a bill that would prevent parents from seeking exemptions from vaccinations for their children on the basis of personal beliefs. SB 277 would also require school boards to provide notifications to parents each year of the vaccination rates at their child's school, presumably so that parents could make informed choices about keeping their child out of school during a disease outbreak.

Public hearings on SB 277 were held this week in the Senate Education Committee. Supporters of the bill raised concerns for their children's health in the wake of the recent outbreak of measles in California. They want all children to either be vaccinated or kept out of school during disease outbreaks. Opponents of the bill say it infringes on their personal rights not to vaccinate their children, and that there was no significant public health crisis posed by the few cases of measles which occurred during the most recent outbreak.

Let's hope this bill passes.

Saturday, April 11, 2015

Is Most of Your DNA Junk?

When scientists first sequenced DNA and began to identify what it was doing, it became apparent that there was a lot of DNA that was not part of any gene, that is, it didn't seem to code for anything. That led to the view, first popularized in the 1970s, that nearly 99% of your DNA was just junk.

But more recently, we've learned a lot more about some of those non-coding regions of DNA. Although they don't specifically code for proteins, there is now evidence that at least some of the non-coding regions seem to be important in turning genes on and off, and thus they may be important in directing the timing of development, among other things. That has led to the currently popular view that there is no junk DNA. At scientific meetings, the discussion sometimes gets a little heated.

But does the finding that some non-coding DNA is useful necessarily mean that there isn't a lot of junk? It's hard to imagine that cells are so efficient that they have managed to eliminate all junk from DNA when it occurs. If a junk sequence did no harm, what would cause it to be selected against during the course of evolution? In all likelihood it would just remain there forever. And that's exactly what "junk DNA" proponents believe.

And so the debate rages on. Before you decide where you stand on the junk vs. no-junk debate going on in biology today, read the fairly well-balanced article in the New York Times.




Tuesday, April 7, 2015

A Polio-Like Disease is Linked to an Enterovirus

Remember that outbreak in California a year ago of polio-like symptoms in more than 20 children? (See this blog Feb. 28, 2014.) It now appears that it is linked to a strain of enterovirus called EV-D68 that first appeared in California in1962.

Enteroviruses are a genus of single-stranded RNA viruses. The best-known enterovirus is the one that causes polio, but there are about 100 strains of non-polio enteroviruses as well; EV-D68 is one of them. Enteroviruses generally enter their victims via the respiratory system, producing primarily flu-like symptoms. But in some patients, EV-68 appears to migrate to the nervous system, where it causes partial or full paralysis of one or more limbs. The nervous system damage caused by EV-68 is not always reversible, and many of the children infected last year still have symptoms of paralysis from their infections.

So, we now know the cause. That's the first step; now we need a cure.

Friday, April 3, 2015

Wearable Smart Devices and Medical Monitoring

The advent of the Apple iWatch and other devices like it are likely to create all kinds of opportunities for monitoring the wearer's health. But in addition the combined data from these devices, if it could be made available to researchers, might take our understanding of certain diseases to a whole new level.

 Last week Apple announced the availability of a suite of software called ResearchKit that is supposed to make it easy to create apps that work with its mobile devices, including the iWatch. ResearchKit is "open source", meaning that anyone can use it to design data-collecting apps. Interesting apps currently available include GlucoSuccess, developed to help diabetics track their activity and keep track of their food intake; Asthma Health, to track asthmatic symptoms; and mPower, designed to track symptoms of Parkinson's disease. Other apps have been developed to monitor and record heart rate and levels of physical activity.

Each of these apps provides useful information to the individual who is wearing the device, and thus possibly to his/her doctor as well. But in addition, the user is asked to be a "citizen guinea pig", that is, to make their personal data available to researchers. The idea is that data collected from tens of thousands of persons in real time might have real power in helping us to learn more about the medical conditions being monitored and how to treat them.

It's worth thinking about the issue of privacy carefully before one decides to participate. But the idea that one could be helping others in the future is a real attraction.

Saturday, March 28, 2015

The Ebola Outbreak is Subsiding

The Ebola outbreak in Guinea, Liberia, and Sierra Leone seems to be subsiding somewhat. The number of new cases is currently running at about 100-150 per week, down sharply from the 800-1,000 cases per week in October-November of 2014. The overall death toll now stands at 10,326 out of 24,907 confirmed cases for a death rate of just over 40%, according to the World Health Organization. There have been only four cases (and one death) in the United States.

Several factors are contributing to the slowing of the outbreak. The virus never went airborne, to the huge relief of health officials. And it turns out that patients are most likely to infect others late in their infection, rather than early. As a result, identifying and isolating infected persons quickly and then tracking down and testing persons with whom they have been in contact has been the key to containment. Getting people to change cultural practices, such as kissing and shaking hands as greetings and washing the dead prior to burial, has slowed the spread of the disease as well.

Nevertheless, it's still too soon to declare the outbreak over. It takes a lot of manpower to find and test all the persons who may have been exposed to someone with the disease, and the three countries with the most cases lack those kinds of resources. Nearly half of all new cases are identified only post-mortem (after death), which makes containment and tracking of exposed persons more difficult.

There are still no cures or effective preventative vaccines for Ebola. Let's hope we can continue to keep this outbreak contained until cures are available.

Wednesday, March 25, 2015

Horizontal Gene Transfer in Humans

People who worry about genetic modification of organisms by the transfer of genes from another species should know that it happens naturally, even in humans.  The transfer of genes from one species to another in nature is called horizontal gene transfer.  It's rare, but it does happen.

What's the evidence for interspecies gene transfer?   In a paper published recently in Genome Biology, researchers at Cambridge University examined currently available genetic databases of primates (including humans), fruit flies, and nematode worms (the groups were chosen because their genetics are fairly well-known).  They then searched the world's known genetic databases for all other organisms for exact matches to specific genes within each group.  Matches within a group (e.g. all primates), are most likely to descent from a common ancestor.  On the other hand, matches between completely unrelated species (e.g. humans and bacteria), are most likely due to horizontal gene transfer at some time in evolutionary history.

The findings suggested all three groups have picked up genes from totally unrelated species over the long time course of evolution, including genes from algae, fungi, and bacteria.   Humans, for example, have picked up more than 145 genes from other species.  That's not a lot out of the 20,000 or so in the human genome, but its at least evidence that horizontal gene transfer does occur.  Most of these horizontally transferred genes in humans were acquired from bacteria early in human evolution.

Are we better off for it or not?  That remains an open question.  In terms of the current debate over the safety of genetic engineering, it's worth noting that the natural process is glacially slow compared to the modern purposeful transfer of genes.   Still, it's interesting that the process does occur in nature.