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Without catalyst, slowest known biological reaction takes 1 trillion years

All biological reactions within human cells depend on enzymes. Their power as catalysts enables biological reactions to occur usually in milliseconds. But how slowly would these reactions proceed spontaneously, in the absence of enzymes – minutes, hours, days? And why even pose the question? One scientist who studies these issues is Dr. Richard Wolfenden, Alumni distinguished professor of biochemistry and biophysics and chemistry at the University of North Carolina at Chapel Hill and a member of the National Academy of Sciences. In 1998, he reported a biological transformation deemed “absolutely essential” in creating the building blocks of DNA and RNA would take 78 million years in water. “Now we’ve found one that’s 10,000 times slower than that,” Wolfenden said.

Male gene sparks immune reaction to stem cell transplants from female donors

Researchers report that in some cases of stem cell transplants from female donors to male recipients, the transplanted cells mount an immunological attack against the product of a gene carried by most cells in the body of male recipients. Emmanuel Zorn, PhD, says it is the first time that the gene, located on the Y chromosome and known as DBY, has been identified following a female-to-male stem cell transplant for leukemia.

Mayo Clinic Begins Enrolling for Smallpox Vaccination Trial

Healthy adults ages 18 to 29 are needed for a research study comparing the safety and effectiveness of two different vaccines for the prevention of the smallpox disease. The study will compare three dose levels of a new vaccine with the current, approved smallpox vaccine that was provided to all U.S. residents during the period of routine smallpox vaccination. The effectiveness of these trial vaccinations will be measured by observing whether or not there is a skin reaction, such as a blister, at the sight of the vaccination. A skin reaction is a typical response to smallpox vaccination. The response also will be measured by examining the size of the skin reaction and the time it takes for the blister to heal. Participants may become immune to smallpox, which would reduce or prevent infection with smallpox.