Friday, March 26, 2010

Re-creating Undifferentiated Cells

People who object to the use of embryonic stem cells (ES cells) for research or for therapeutic purposes continue to hope that induced pluripotent stem cells (iPS cells) might just be the answer. If adult cells could somehow be coaxed back (induced) into a state where they were once again capable of differentiating into all kinds of cells (i.e. were pluripotent), then embryonic stem cells just wouldn’t be needed any more.

Researchers announced several years ago that they had, in fact, found a way to create iPS cells. But are currently available iPS cells just as good as ES cells? In the first side-by-side comparisons of iPS and ES cells, two groups report that they are not. Both groups report that while iPS cells can differentiate into many cell types, they just are not very efficient at it, at least not yet.

The results are a disappointment, perhaps, but don’t count iPS cells out just yet. Scientists are still in the early stages of understanding how to create iPS cells in the first place. As the techniques improve, perhaps they’ll begin to look more and more like ES cells after all. And that would be a scientific advance welcomed by all.

Sunday, March 21, 2010

Potential Alzheimer's Drug Flames Out

A closely-watched drug that was supposed to offer hope to Alzheimer’s sufferers failed miserably in Phase III trials this month, according to a press release from Pfizer, one of the pharmaceutical companies involved in its development. In all likelihood all further research on the drug will stop.

It wasn’t supposed to end like this, although looking back it may not be as surprising as it sounds. The drug, called Dimebon, was actually an antihistamine previously sold only in Russia. The Phase I and Phase II trials (efficacy in animals and limited safety tests in humans) were performed in Russia, and then the drug was patented and brought to the United States for Phase III trials and future marketing as an Alzheimer’s treatment. Apparently it doesn’t work.

Although people sometimes complain (rightly) that the drug approval process in the United States is expensive and time-consuming, there’s a good reason for the process. It protects us all.

Monday, March 15, 2010

Caffeine Made Easy

Remember Sweet’n Low, the first really convenient sugar substitute? Well, now somebody has finally come up with a similar easy-to-use product containing caffeine. Fein energy crystals (pronounced FEEN) are being promoted as an energy-boosting product that can be added to any drink, including water. Fein has no calories, no artificial ingredients, and no taste, according to the company marketing it. Drop a single stick of FEIN into your drink of choice and you’re getting 75 mg of pure crystalline caffeine, roughly the amount of caffeine in some energy drinks. And Fein costs less than 70 cents per stick. You probably won’t find it in stores yet, but it’s available over the internet.

Henceforth, getting that caffeine buzz (if that’s important to you) will be as easy as sweetening your tea. This is not an endorsement; just a fact.

Saturday, March 13, 2010

Should Older Women be Vaccinated Against HPV?

The U.S. Centers for Disease Control and Prevention (CDC) recommends that all girls and women between the ages of 11 and 26 be vaccinated against the strains of human papillomaviruses (HPVs) that cause cervical cancer. But what about older women; wouldn’t they benefit as well?

The answer appears to be no, or at least not very much. A study of over 9,000 Costa Rican women conducted over a seven-year period found that older women (over 40) tend to get fewer new HPV infections. They also found that HPV infections do not progress towards cancer any faster in older women than in younger women.

Cancer develops in only a small fraction of women who have an HPV infection during their lifetimes, and most HPV infections clear up on their own within a couple of years anyway. Even among women who do develop cervical cancer as a result of an HPV infection, it takes about 25-30 years on average for the cancer to develop fully to the metastatic stage. Therefore, vaccinating older women is not of much use. The ideal time to vaccinate women and girls is before they become sexually active so that they never have an HPV infection in the first place.

Wednesday, March 10, 2010

The U.S. Birth Rate is on the Rise

A record 4.3 million babies were born in the U.S. in 2007, according to a summary of birth statistics published each year in the journal Pediatrics. The birth rate (number of births per 1,000 women) has been climbing for a couple of decades, though it is nowhere near what it was 100 years ago. The record high number of births is due both to a recent trend upward in the birth rate and the larger U.S. population now than 100 years ago.

A noteworthy trend in the data is that women are having their babies later than they did just 15-20 years ago. Birth rates were lower in 2007 than in 1990 for women under 30, but higher in 2007 for women over 30. Also noteworthy is a continued rise in the number of births to unmarried women; it’s now a record 40% of all births.

Saturday, March 6, 2010

Athlete Caught Doping with Growth Hormone

British rugby player Terry Newton has the distinction of being the first athlete ever caught doping with growth hormone to boost muscle mass. He’s been banned from rugby competition for two years.

Until recently athletes had assumed that human growth hormone doping was undetectable, because the synthetic form of growth hormone looks exactly like natural growth hormone. But then scientists discovered that the body actually produces several different forms of the hormone, and that by examining the ratio of these different forms in blood they could tell if the pure synthetic form had been administered. Anti-doping agencies also began requiring random blood tests rather than just tests after athletic events, because the hormone disappears from the blood just days after administration. It was a random test that caught Mr. Newton.

The U.S. National Football League and Major League Baseball have shown interest in the test but so far it has not been instituted, in part because it requires a blood sample.

Friday, March 5, 2010

Feeding the World in 2050

Forty years from now will there be enough food to supply the world’s growing human population? Perhaps the best answer is “It depends”. It depends on how much we can improve the energy efficiency of producing and transporting food. It depends on what we are willing to eat (“Excuse me sir – would you like the beef or the crickets?”). It depends on what we do about climate change, how much damage we do to the environment, and how efficiently we use our precious supplies of fresh water. It depends on whether we’re willing to use genetically modified crops.

A special section of Science magazine available online examines some of these and other issues on the subject of food security. There are some pretty interesting and thought-provoking ideas out there. There’s even an article on what kinds of careers might be available for persons interested in this subject.