Last year astudy reportedthat a vaginal gel containing 1% tenofovir (an anti-HIV drug) was partially effective in preventing HIV infection in at-risk women in Africa (see this blog Sept. 5, 2010).Researchers were particularly interested in developing a gel against HIV because it would be a prevention method controlled by women, rather than by men. The study was hailed by a breakthrough by AIDS researchers, and several large follow-up studies were undertaken to to confirm the findings.

The results have been very disappointing.One of the follow-up trials was halted recently when it became clear that the vaginal gel wasnotgoing to be effective in reducing the rate of HIV infection in what was thought to be a similar group of at-risk women.(See also thePBS report.) Researchers are scratching their heads and trying to work out the differences between this and the previous study to see if they offer any clues as to why the recent trial failed.In the meantime, another study is still ongoing.

But let's put the disappointment in perspective. This is the scientific process at work.Hypotheses are made and tested, findings repeated and confirmed (or not confirmed), hypotheses modified and tested again….its a continuous process that brings us closer to the truth through repeated success and failure, trial and error.We’ll just have to wait for the next instalment in this ongoing saga.In the meantime, don’t expect a vaginal gel against HIV infection to hit the market any time soon.

Last month Congress ended the federal subsidy for fuel-grade ethanol made from corn, according to news reports.The original idea behind the 30-year subsidy was that ethanol would help the U.S. reduce its dependence on foreign oil. It never accomplished that. In fact, the subsidy (45 cents per gallon) cost the taxpayers 6 billion last year, driving up the price of corn feed stocks for livestock and increasing the price of many foods.

But even with the subsidy removed, there will still be ethanol in our gasoline.The federal Renewable Fuels Standard still mandates that we use 36 billion gallons of biofuels per year by 2022, compared to 7.5 billion gallons this year.And along with eliminating the subsidy for U.S. production of ethanol from corn, Congress also removed the tariff on ethanol imported from Brazil.The Brazilians make ethanol from sugarcane, which turns out to be much more energetically efficient than making ethanol from corn.So, a) We’ll still be using ethanol, and b) It’ll probably come from Brazil.So much for reducing dependence on foreign suppliers of energy…

Still in force is a $1.01 per gallon production subsidy for ethanol derived from cellulosic biomass, such as wood, grass, and waste plant materials.We can only hope that encouragement of the fledgling cellulosic biomass fuels industry will pay off better than the subsidy for corn-based ethanol ever did.

About a year and a half ago I reported on the first clinical trial of a therapy using stem cells (this blog, Aug. 1, 2010).The trial, run by Geron Corporation, was designed to treat patients suffering from spinal cord injuries with neuronal cells grown from stem cells.

This past NovemberGeron announcedthat it was cancelling the clinical trial and its entire stem cell research program. In a statement, the company said only that it will “discontinue further development” of its stem cell programs in order to focus on several promising new cancer drugs. According to Geron it was a decision based on the need to save money. By abandoning its stem cell research program, Geron will lay off 66 staff members and save about $25 million a year, according to a news article inScience.

Only four spinal cord injury patients were treated before the trial was terminated..Preliminary results showed that their conditions did not improve after treatment.

Cancellation of the trial is certainly a setback for stem-cell-derived therapies, but it is not an outright disaster.At least one other clinical trial of a stem-cell-derived therapy, for macular degeneration, is already underway at a company called Advanced Cell Technology.And it’s still possible that another company will buy Geron’s stem cell program assets, which included work-in-progress on treatments for several other diseases.