Saturday, July 31, 2004

Roundup of Interesting Science News

Lithium may fend off Alzheimer's disease
Published online: 27 July 2004; | doi:10.1038/news040726-4
Helen Pilcher

Manic depression therapy could prevent brain degeneration.

Lithium, a common treatment for manic depression, might also help to stave off Alzheimer's disease. Patients who take the drug to stabilize their mood disorder are less likely to succumb to dementia, a study reveals.

For the last 30 years, lithium has been used to control the mood swings of patients with bipolar disorder, also known as manic depression. But over the last decade, an increased understanding of how the drug works has widened the scope for its use. Researchers now think that the simple salt could slow the progress of degenerative brain disorders, such as Huntington's and Alzheimer's disease.

Paula Nunes and colleagues from the University of São Paulo, Brazil, studied 74 elderly people with bipolar disorder. Four percent of those taking lithium had Alzheimer's disease, compared with 21% of patients who were not taking the drug.

The researchers conclude that lithium therapy may lower the risk of developing Alzheimer's disease. They presented their data at the 9th International Conference on Alzheimer's Disease and Related Disorders in Philadelphia, Pennsylvania, last week.

"The numbers are small, so it's difficult to draw any firm conclusions," says Alzheimer's researcher Bart De Strooper from the University of Leuven, Belgium. But the results do back up tissue culture and animal studies, which hint that lithium can tackle the two hallmarks of Alzheimer's disease, namely tangles and plaques. [...]

Gene therapy reaches muscles throughout the body and reverses muscular dystrophy in animal model
Jul. 26, 2004
Walter Neary

Researchers have found a delivery method for gene therapy that reaches all the voluntary muscles of a mouse -- including heart, diaphragm and all limbs -- and reverses the process of muscle-wasting found in muscular dystrophy.

"We have a clear 'proof of principle' that it is possible to deliver new genes body-wide to all the striated muscles of an adult animal. Finding a delivery method for the whole body has been a major obstacle limiting the development of gene therapy for the muscular dystrophies. Our new work identifies for the first time a method where a new dystrophin gene can be delivered, using a safe and simple method, to all of the affected muscles of a mouse with muscular dystrophy," said Dr. Jeffrey S. Chamberlain, professor of neurology and director of the Muscular Dystrophy Cooperative Research Center at the University of Washington School of Medicine in Seattle. He also has joint appointments in the departments of medicine and biochemistry.

Chamberlain is the senior author of the paper describing the results, which will be published in the August edition of Nature Medicine. The paper describes a type of viral vector, a specific type of an adeno-associated virus (AAV), which is able to 'home-in' on muscle cells and does not trigger an immune system response. The delivery system also includes use of a growth factor, VEGF, that appears to increase penetration into muscles of the gene therapy agent. Chamberlain said the formula was the result of about a year of trying different methods.


Old Age Was Secret of Modern Humans' Success
July 07, 2004
Sarah Graham

Humans began to live long and prosper only about 30,000 years ago, researchers report. Results published online this week by the Proceedings of the National Academy of Sciences reveal a striking increase in human longevity during the Upper Paleolithic Period when the number of people surviving to old age increased four-fold.Rachel Caspari of the University of Michigan and Sang-Hee Lee of the University of California at Riverside, examined 768 hominid dental samples from a variety of locations and time periods. Included in the selection were fossils from Australopithecus, Homo erectus, and Neandertals from Europe and Western Asia. The researchers analyzed the amount of wear on the molars to determine the age of the individuals and defined as “old” those who reached double the age of reproductive maturation. A comparison of the number of old and young individuals in each time period revealed a dramatic increase in life span that occurred about 30,000 years ago. (The above photograph  shows the skull of an early modern human from the site of Cro-Magnon in France.) “Significant longevity came late in human evolution and its advantages must have compensated somehow for the disabilities and diseases of older age, when gene expressions uncommon in younger adults become more frequent,” the scientists write.

The findings support the so-called grandmother hypothesis, which posits that older women no longer responsible for their own children help support the group by strengthening social bonds and providing greater opportunities to pass on specialized knowledge. "There has been a lot of speculation about what gave modern humans their evolutionary advantage,” Caspari remarks. “This research provides a simple explanation for which there is now concrete evidence: modern humans were older and wiser.”

Commentary:  The first article shows that lithium has a therapeutic effect on brain tissue, in at least one degenerative brain disease.  This is of interest, because it refutes the notion that psychiatric medication "justcovers up the symptoms."  Previous posts at The Corpus Callosum have shown that antidepressants can reverse the shrinkage of the hippocampus in posttramatic stress disorder, and that eltroconvulsive therapy causes the migration of neuronal stem cells in the brain, leading to the creation of new synapes.  Now, we see that lithium also hasa beneficial effect on brain tissue.

The second article shows that gene therapy -- the practice of treating disease by inserting new genetic material into a person -- is feasible, at least for mice.  As the author cautions, it is too early to know if this technique will be safe or effective for humans.  Still, it is extremely encouraging.  And those of you who watched the Jerry Lewis Muscular Dystrophy Association Telethon, and perhaps even donated money, can rest assured that it was not a scam.  Those research dollars really do matter.

The third article, about some reasearch done by Ann Arbor's own Dr. Rachel Caspari, provides some information about modern evolutionary theory.  Critics of evolutionary theory have, at times, argued that the theory must be false, because it predicts that humans should die once they get past reproductive age.  Drs. Caspari and Lee show that this is not the case.