Science Writer

"Progeria" is not the name of a cruise ship. Nor does the term describe a prize-winning flower. Progeria is an exceedingly rare, fatal childhood disorder, which visits agony on its victim and parents alike.

It prematurely inflicts the signs and symptoms of aging on an infant in its first year of life, and deprives that youngster of life itself at about age 13. Progeria adolescents die literally of old age. The cause of teen-age death is usually myocardial infarction or congestive heart failure.

Progeria strikes one in 4 million to 8 million births worldwide. Perhaps 100 victims are alive today, estimated the Progeria Research Foundation Inc. in Boston.

An infant with progeria is comparable to a normal person in his 80s or 90s. Dry wrinkled skin, gray hair or bald head and narrow, wizened facial features are visible hallmarks of advanced years, and of progeria children. They begin developing these obvious stigmata of accelerated superannuation around their first birthday. Heart disease, premature atherosclerosis and coronary heart disease, pathological fractures and other geriatric ailments follow.

Despite its near-vanishing rarity, progeria is the object of intense research into the molecular and genetic mechanisms of its manifestations. Last week alone, two major scientific journals, Nature and Science, separately reported the long-sought mutant gene that causes the disorder.

Nature's article bears the title "Recurrent de novo point mutations in lamin A cause Hutchinson-Gilford progeria syndrome." It was released April 16, 2003. The paper's senior author is Francis Collins, director of the National Human Genome Research Institute. (Hutchinson-Gilford progeria syndrome [HGPS] is the ailment's formal designation.)

Sciencexpress published its one-page account under the title "Lamin A truncation in Hutchinson-Gilford progeria." Its 11 co-authors are at various research centers in Marseilles, France, sponsored by INSERM - the National Institute of Health and Medicine in France. The lamin A protein is the structural scaffolding that holds the nucleus together. It has been studied for years.

"Pinpointing the gene," Sciencexpress observed in a press release, "is a critical starting point for developing therapies for the disorder, and programs to screen individuals for the defective gene. The authors studied the DNA sequences of lamin genes from patients affected with HGPS. They found just one abnormality, the substitution of a single base within a segment called axon 11. Its dominant mutation means that individuals who inherit a defective copy of the gene from either parent develop HGPS."

Collins told the press and public in an announcement by the Progeria Foundation that "isolating the progeria gene [as announced in Nature] is a major achievement for the medical research community. The discovery not only gives hope to children and families affected by progeria, but also may shed light on the phenomenon of aging and cardiovascular disease."

Blood-Forming Stem Cells Have Potential For Application In Regenerative Medicine

In bone marrow, hematopoietic (blood-forming) supporting cells form a microenvironment called a "niche." By producing growth factors, adhesion molecules and matrix proteins, they govern the homing, growth, survival and differentiation of hematopoietic stem cells (HSCs). These stem cells can't be maintained in vitro without stromal (connective tissue) cells, even if they are provided with growth factors.

Virologists at the National Cancer Institute have authored an article in Nature Immunology, released online March 31, 2003. Its title: "A stromal membrane protein that supports hematopoietic stem cells." In the paper researchers show that a mammalian homologue of a fruit fly gene encodes a membrane protein that is involved in the hematopoietic support of certain mouse stromal cells. Their data suggest that the homologue is cleaved by metalloproteinase enzymes, and that it supports those stem cells, which have potential for regenerative medicine.

Medical Politico Insists FDA Ban Natural' Ephedra As Hazardous, But Agency Stalls

"Ephedra, marketed as a natural' dietary supplement, is in fact extremely harmful, and should be banned by the FDA." So said Sidney Wolfe, director of the Public Citizen's Health Research Group in Washington. He is author of a one-page Policy Forum in the current Science, dated April 18, 2003, titled "Ephedra: Scientific Evidence Versus Money/Politics."

Wolfe claimed that, despite convincing evidence of heart attacks, arrhythmias, strokes and more than 100 reports to the FDA of ephedra-related deaths, the agency has succumbed to pressure from ephedra manufacturers, and allows sales of the supplement to continue in the U.S.

In 1983, the FDA banned all over-the-counter drugs that included both synthetic ephedrine and caffeine. The agency is now finalizing a ban on drugs that contain ephedrine alone. As a dietary supplement, ephedra hasn't been subject to required safety or efficacy studies, but the U.S. Army and Air Force commissaries, the National Football League, the National Collegiate Athletic Association and the Canadian government have all outlawed the substance. In June 2001, it warned Canadians not to use those products, and in January 2002, it announced a recall of "ephedra/ephedrine products with labeled or implied claims for appetite suppression, weight loss promotion, metabolic enhancement, increased exercise tolerance, body-building effects, euphoria, increased energy or wakefulness, or other stimulant effects."

At a recent U.S. Senate hearing on ephedra alkaloids, Wolfe noted, "Acting FDA Commissioner Lester Crawford conceded that if these products were drugs, not dietary supplements, they would be off the market."

Advance Hint Well Before Reward Promise Sets Off Rats' Addictive Dopamine Release

It's common knowledge that dopamine levels in the brain increase during addictive behaviors such as eating, sex and drug-taking. Psychologists and chemists at the University of North Carolina at Chapel Hill trained rats to press a lever in order to get a cocaine reward. They found that a brief dopamine pulse was released seconds before the animals got near the lever. In rats that had learned to associate a visual cue with a forthcoming hit, the cue itself sufficed to trigger the dopamine. Therapies aimed at preventing one or both of these signals, the authors suggested, "could be effective treatments for addiction."