Setback for Vaginal Gel Against HIV

Last year a study reported that 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 was not going 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 the PBS 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.

Congress Ends the Ethanol Subsidy

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.

Stem Cell Therapy Trial Halted

About a year and a half ago I reported on the first clinical trial of a therapy using stem cells (see "First Human Stem Cell Trial"). 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 November Geron announced that 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 in Science.

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.

Storing Solar and Windmill Energy

Both solar and windmill energy generating systems suffer from one drawback – they’re inconsistent. The biggest problem isn’t how to produce electricity from them for the power grid; it’s how to store energy from these two sources until it is needed.

The energy storage problems (and solutions) are different for solar and wind energy. Typically, solar energy systems generate heat, which powers steam turbines to produce electricity. For solar energy systems, the problem becomes how to store heat until it is needed. The current technology stores heat in tanks of molten salt heated to about 700 degrees Fahrenheit, or in solid blocks of concrete.

Windmills generate electricity directly without heat, but of course they only work when the wind is blowing. A variety of battery technologies are currently available to store excess electricity generated by windmills during peak generation periods. But so far, batteries can’t store enough energy to power a major power grid for any significant length of time. For long-term energy storage, excess electricity from windmills is used to pump water uphill to storage reservoirs. When power is needed, the water can power turbines to produce electricity. One innovative alternative is storage of compressed air in huge underground caves!

Renewable energy production and storage – no doubt we’ll hear a lot about it in the years to come. For more on this subject, see the articles on storing solar and windmill energy in the Nov. 18 issue of Science.

Stem Cell Fraud

The FBI has charged four men with illegally trafficking in stem cells, according to a report in a Charleston, S.C. newspaper. Apparently, one of the men convinced birth mothers at a clinic in Del Rio Texas to donate their placentas and umbilical cords to medical research. Instead, he allegedly sold the placentas and umbilical cords to a man posing as a doctor from a laboratory in Arizona, who shipped them to a third person, a faculty member at the Medical University of South Carolina. Stem cells were harvested in South Carolina and then shipped back to Texas, where a fourth person who operated a “biotherapy clinic” allegedly convinced terminally ill patients that the stem cells would be a miracle cure for diseases such as ALS, MS, Parkinson’s disease, and cancer. The patients traveled to Mexico for the stem cell injection procedures. The four men allegedly made more than $1.5 million from the scheme.

Stem cells are being used legitimately in human clinical trials, but those trials follow FDA guidelines that include government oversight and evidence of the patients’ informed consent. That was not the case here. According to an FBI spokesman, this was “a scheme whereby the suffering and hopes of victims in extreme medical need were used and manipulated for personal profit. The predatory and opportunistic nature of the crimes alleged in this indictment mirrors images from science fiction.”

We’ve all heard of the potential of stem cells, and we all hope that some day perhaps they will be a miracle cure for certain diseases. But the hard truth is that stem cell research and especially treatment of disease with stem cells is still in its infancy. No one should be experimenting on unsuspecting patients.

Genital Herpes Vaccine Fails

An experimental vaccine designed to protect against herpes simplex virus type-2 (HSV-2) has failed completely in clinical trials, according to a preview of an article in the New England Journal of Medicine this week. The study involved over 8,000 women.

http://www.nejm.org/doi/full/10.1056/NEJMoa1103151

HSV-2, also known as genital herpes, is transmitted via sexual contact. It causes painful blisters that may recur at various times in life after initial infection. Approximately half a million people worldwide currently are infected with genital herpes. At the moment there is no known cure for HSV-2 infection, and no other ongoing effort to find one. Genital herpes is considered to be a rather trivial disease by pharmaceutical companies because although it can cause irritating and painful blisters, it is not particularly dangerous. Given the negative result from this vaccine and several others before it, there may not be much of an effort put into finding a cure in the near future. We may just have to live with genital herpes for a while longer.