Sunday, February 27, 2011

Taxol and Repair of Spinal Cord Injuries

One of the challenges in facilitating repair of the spinal cord after spinal cord injuries has been to get axons to re-grow through the damaged area. Usually the process of axonal re-growth is inhibited by the formation of scar tissue.

But now researchers have discovered a potential new weapon in the treatment of spinal cord injuries – taxol, the same drug that is currently used to inhibit the growth of certain cancers. It turns out that taxol produces “stabilization” of microtubules in damaged areas of the spinal cord, which in turn reduces scarring and reduces the production of certain factors which normally inhibit axonal regeneration. The result is that axons tend to grow more readily through taxol-treated lesion sites.

So far, taxol has only been shown to work in rats. Nevertheless, these encouraging results could pave the way for future clinical trials in humans. Perhaps some day taxol will become part of the normal treatment regimen for spinal cord injuries.

Monday, February 21, 2011

Lymph Node Surgery for Breast Cancer

For decades, the standard treatment for women who have been diagnosed with early-stage breast cancer has been to perform a biopsy on a nearby lymph node, called a “sentinal” lymph node, to see if the cancer has metastasized beyond the breast. If it has, then the usual recommendation is surgery to remove some or most of the thirty axillary (armpit) lymph nodes as well, to try to halt the spread of cancer. The surgery is extensive, and recovery is painful and slow.

A new study published in the Journal of the American Medical Association reports that removal of armpit lymph nodes may not be necessary any more, given the current effectiveness of post-surgical radiation therapy and chemotherapy. In the study, 891 women who had undergone a lumpectomy for early stage breast cancer were randomly assigned to just sentinal node removal, or removal of at least 10 of the axillary lymph nodes. There were no differences in survival rates or disease-free survival rates between the two groups for the entire eight years of the study.

The authors recommend that physicians consider carefully whether more radical axillary node surgery is really necessary in most patients. Some cancer centers are already starting to change their cancer treatment protocols as a result of these new findings.

Thursday, February 17, 2011

The Vaccinations-Cause-Autism Fraud

Anyone who still persists in believing that childhood vaccinations have anything to do with the development of autism should read the three well-documented articles by investigative reporter Brian Deer published recently in the prestigious British Medical Journal. The first article is presented here. For those who don’t have the time, here’s a brief synopsis:

The original research article allegedly showing a causal link between vaccinations and autism was later shown to be a deliberate fraud. The paper, published in 1998 by the Lancet, was retracted in 2010 after it was shown to contain numerous misrepresentations. The paper’s author, Dr. Andrew Wakefield, was investigated by the UK General Medical Council and ultimately lost his license to practice medicine. Records released during the investigation show that Dr. Wakefield was paid nearly $700,000 by a British lawyer who was preparing a class-action lawsuit against vaccine-makers.

Since 1998, study after study has failed to validate Dr. Wakefield’s work and failed to show any causal link between childhood vaccinations and autism. And yet, some parents of autistic children still believe in that there may be a causal link. Actress Jenny McCarthy, herself a mother of an autistic child, is one of them. Ms. McCarthy has appeared on the Oprah Winfrey show to promote the vaccination-autism “cause” and has written several books about autism. I have yet to see an admission from her that she may have been wrong about vaccines.

Sorry, Ms. McCarthy, you lose on this one. Give it up before you look even more foolish than you already do.

(Topic for debate: Why do some people continue to believe in something despite overwhelming evidence in favor of just the opposite? What does that continued belief do for them?)

Sunday, February 13, 2011

Analyzing and Storing Genomics Data

In just the last 10 years, the cost of sequencing a million DNA base pairs has dropped from $10,000 to just $1. A single modern DNA sequencing machine can generate more data in a single day than could once be generated in a decade. Consequently, genomics researchers now face a looming problem, according to an article in Science - the speed and efficiency with which DNA sequence data can be produced will soon outstrip the ability of most computers to analyze and store the data! That’s right; despite huge gains in computer speed and storage capacity over the years, the computers are now lagging behind.

To combat this growing problem, bioinformatics specialists are increasingly turning to “cloud computing”, whereby data are analyzed and even stored on networks of computers off-site. But cloud computing raises complex new issues of data security, particularly when that data involves human subjects.

Perhaps if the cost of sequencing DNA continues to fall it may not even be necessary to store the data long-term; it could just be regenerated as needed.

Wednesday, February 9, 2011

Smallpox - Gone Forever?

A deadly viral disease called smallpox killed several hundred million people in the 1800s. Thanks to the development of smallpox vaccines and a concerted effort worldwide, the disease was finally declared eradicated in 1979. To this day, smallpox is the only infectious human disease ever wiped out completely.

Nevertheless, the spectre of a return of smallpox remains. That’s because more than 500 vials containing the smallpox virus remain in tightly guarded, allegedly secure facilities in the U.S. and Russia. The question is, what to do with these vials? Some scientists and politicians (particularly in the U.S. and Russia) argue that stocks of the smallpox virus are still needed for research and for the development of new diagnostics, safer vaccines, and effective antiviral drugs. Others argue that over the past several decades we’ve learned just about all we can about the virus, and that the mere existence of these vials represents a risk that some day the disease could return, particularly if a vial were to fall into the hands of terrorists.

The World Health Assembly (WHA), an organization comprised of health ministers, will decide in May whether to recommend a firm deadline for the final destruction of all remaining vials. But don’t count on the elimination of every last smallpox virus from the planet any time soon, even if a deadline is announced. An earlier deadline of 1990 was postponed indefinitely when both the U.S. and Russia argued against it. It’s more likely that a compromise will be reached to reduce stockpiles without eliminating them completely.

Saturday, February 5, 2011

Drug Reduces Deaths from Bleeding

A drug that prevents blood clots from breaking down has recently been shown to reduce deaths from uncontrolled bleeding following traumatic injury. In a study of over 20,000 patients, the drug (tranexamic acid, or TXA), reduced deaths due to bleeding after traumatic injury by 15%.

TXA has been used by doctors for some time. Surgeons sometimes administer it before surgery to prevent bleeding in surgical patients, and it has been prescribed for women with particularly heavy menstrual periods to prevent excessive blood loss during menstruation. But this is the first real evidence that the drug is also effective when given to patients after traumatic injury with blood loss. The drug seems to have no significant negative side effects.

Over three million people a year die of traumatic injury. Blood loss is usually a major factor in the patient’s death. This drug might save a lot of lives if it were available everywhere on short notice.

Wednesday, February 2, 2011

Faking a Foul in Sports

Do athletes ever fake being fouled by an opposing player in order to invoke a penalty against the opposition? Yes, according to researchers who study human behavior and game theory. Game theory predicts that in any venue, not just sports, dishonest behavior is likely to increase when the potential benefit to the dishonest individual is high and the risk of being caught and punished is low.

Apparently that's what happens in soccer. According to researchers, faked collisions (called “dives”) do not occur randomly over the entire field – they are most common near the goals, where a penalty kick can win or lose a game and where it is more difficult for the referee to judge the fall correctly by virtue of his/her position on the field.

Consistent with game theory, reducing dives in soccer might best be accomplished by ejecting players more often for allegedly taking a dive and by positioning referees closer to the goals.