Health Highlights: June 25, 2009

• Study Offers Surprise Discovery About Muscle Stem Cells
• Erection Molecule Also Plays Major Role in Brain: Report
• South Pole Doctor Who Treated Own Breast Cancer Dies
• Only Four Shots Needed for Rabies Protection
• Insurance Improves Odds of Having a Doctor: Report

Here are some of the latest health and medical news developments, compiled by editors of HealthDay:

Study Offers Surprise Discovery About Muscle Stem Cells

Genes that play an important role in the formation of muscle cells in embryos and newborns aren't normally active in adult stem cells, says a U.S. study that could change the way scientists approach stem cell transplants for muscle injuries and diseases such as muscular dystrophy.

The surprise finding by researchers at the Carnegie Institution in Baltimore appears in the June 25 online edition of the journal Nature.

In tests on mice, the researchers focused on two genes (Pax3 and Pax7) involved in the production of muscle stem cells in embryos.

"I thought that if they are so important in the embryo, they must be important for adult muscle stem cells. Using genetic tricks, I was able to suppress both genes in the adult muscle stem cells. I was totally surprised to find that the muscle stem cells are normal without them," lead researcher Christoph Lepper said in a news release.

"We are just beginning to learn the basics of stem cell biology, and there are many surprises," added Allan Spradling, director of Carnegie's Department of Embryology. "This work illustrates the importance of carrying out basic research using animal models before rushing into the clinic with half-baked therapies."

-----

Erection Molecule Also Plays Major Role in Brain: Report

Nitric oxide -- a molecule that controls blood pressure and male erections -- may also have a major effect on how people think and hear, British researchers report.

They believe that studying the effects of nitric oxide in the brain may help lead to new treatments for disorders such as epilepsy, migraine headaches, Alzheimer's disease and chronic pain, BBC News reported.

It's believed that nitric oxide acts as a signaling molecule that helps cells communicate with each other.

"It is hoped that this research will go some way to solving the complexity of communication between brain cells, and therefore provide openings for therapeutic strategies against debilitating conditions," said lead researcher Adam Tozer. "It will also help to shed light on communication in the healthy brain and this will enable a greater understanding of how we think."

Previous research has suggested that high levels of nitric oxide have a toxic effect on the brain and may cause serious disorders, such as Alzheimer's disease, BBC News reported.

-----

South Pole Doctor Who Treated Own Breast Cancer Dies

The American doctor who diagnosed and treated her own breast cancer while on a research mission at the South Pole in 1999 has died of cancer.

Dr. Jerri Nielsen FitzGerald, 57, was the only doctor at the National Science Foundation Amundsen-Scott South Pole Station when she found a lump in her breast. Weather conditions made a rescue impossible, so she performed a biopsy on herself and then treated herself with anti-cancer drugs for months until she was taken back to the United States.

Her cancer remained in remission until August 2005. She died Tuesday at her home in Southwick, Mass., her husband, Thomas FitzGerald, said Wednesday, the Associated Press reported.

Neilsen FitzGerald described her South Pole ordeal in a best-selling book that was made into a TV movie. During the last decade, she traveled the world to speak about how cancer had changed her life. She also worked as a roving emergency room doctor at hospitals in the northeastern United States.

-----

Only Four Shots Needed for Rabies Protection

People exposed to a rabid animal need only four vaccinations, not the five currently recommended, a U.S. immunization advisory group has decided.

The Advisory Committee on Immunization Practices voted Wednesday that four shots given within the first 14 days of exposure to rabies provides sufficient protection, the Associated Press reported.