Stress Lowers Sperm Count By Overwhelming Cells That Make Testosterone
...formation. Offering the first evidence that stress acts locally within the testes, via theLeydig cells, th...ng cells do not begin to manufacture sperm. Enzyme acts as a double agent 11ßHSD-1 assists and neutralizes glucocorticoid as necessary. As Leydig cells...Researchers Discover New Genetic Risk For Alzheimer's Disease
... "From our data, we might predict that APOE acts as a chaperon for theamyloid protein. With what we know from in vitro studies, it would make sensethat APOE is inducing more of the normally soluble amyloid to deposit in thebrain as plaques," Goate explained. "I think this is the first result that h......ample, a negativel y-charged ion exchange material acts like a sponge for positively-charged calcium ions in hard water. Eventually, however, the ion exchange material becomes filled with calcium and must be regenerated by a series of chemicaltreatments. A concentr ated salt-water solution is used to remo...Females' Siren Song Initiates Courtship Duets In African Frogs, Columbia Biologists Find
... Estrogen circulating in sexually receptivefemales acts on the neurons that control their mating song to strengthen theconnection between neurons and vocal muscles, the scientists have found. "Theeffect resembles the action of estrogen in the mammalian central nervoussystem," Professor Kelley said. "Tha...Jefferson Researchers First To Create Genetically Engineered Mouse To Study Photoaging
...e learned from the CAT reporter gene that thelight acts as a switch, resulting in up to a 30-fold increase in elastin promoter activity indicating photodamage." Drs. Uitto and Bernstein were able to detect this increase in elastin asearly as 24 to 48 hours after irradiating the mice. "Our transge...Long-Standing Puzzle Of Immune System Is Solved By UCSF Researchers
...micelacking the gene, suggesting that Pms2 somehow acts differently to play anactive role in hypermutation of these genes in B cells. Prior to cell division, when a cell duplicates its geneticmaterial, the double-stranded DNA helix unzips and each strand serves as atemplate for making new DNA. S...Studies Underscore Link Between Nutrition And Nonmelanoma Skin Cancers
...ng a physician. Selenium, a mineral that acts as an antioxidant, also may play a role inreducing the risk of skin cancer. Selenium is available liberally in foodsources such as brown rice, whole grains and Brazil nuts. One single Brazil nutprovides 120 micrograms of the mineral, exceeding the 1...Study Shows: Just Say NO To Bone Loss
..." Osdoby says. "Our working hypothesis is that NO acts as aself-regulating mechanism in osteoclasts." Lar...ds to destroy proteins and DNA and RNA, butit also acts as a signal molecule," Osdoby says. "We hope the information we'regathering will help in developing...Jefferson Researchers Use Gene Therapy To Treat Rare, Inherited Brain Disease
...he fatty covering surrounding the nerve cells that acts as an insulator. The disease is caused by a genetic flaw in which an enzyme fails to be produced. The disease is incurable, resulting in the over-production of a toxic compound in the brain, N-acetyl-aspartate (NAA). Death usually occurs between the ...Heart and Soul: The Blood Vessels And Brain Use Common Guide
... its established effect on endothelial cells, also acts back on thetumor cells themselves to help them hol... whether VEGFacts on neurons or whether semaphorin acts on endothelial cells, which carryneuropilin. If semaphorin turned out to inhibit endothelial cell mo...Prostate Cancer Switch May Yield Map Of Cancer Machinery, Targets For Drugs
...ngbetween the two lengths of RNA code. That switch acts as a molecular "scissors"to activate one form of FGF-R2, while suppressing another. The phenomenon iscalled "alternative splicing," said Garcia-Blanco, an associate professor ofpharmacology and cancer biology. Carstens, who initiated experiments on t...Rapid Progress Reported On New Class Of Anti-Cancer Drugs
... the active site -- into which farnesyl nestles -- acts as a"molecular ruler" to discriminate between farnesyl and the longer geranylgeranylmolecule. Beese's next studies will aim at obtaining a structure of FTase withboth the farnesyl molecule and the Ras protein bound at the active site. "All t...Researchers Discover Existing Drugs May Prevent Enlarged Hearts
...controlled by a single protein, calcineurin, which acts as a gatekeeperto the cells nucleus, the control room where specific moleculesregulate gene function. When stimulated by a sustained increase in thecells calcium level, calcineurin activates its target protein, NFAT3,which then enters the nucleus and...... going," said Levy. "Each subsequent exposure then acts as a kind of booster." He said theresearchers do not know why the CD8+ cell antiviral response occurs in somepeople and not in others. In the second study from the Levy laboratory presented at FASEB, Barkeridentified a molecular link that is critical...Biochemist Solves Riddle Of Collagen Stability
...ry about the stability of collagen, a protein that acts like a "solder" to give the body its structure and shape. A new explanation of the phenomenon, published April 16 in the journal Nature, could expand the potential of collagen in treating serious disease, healing wounds and repairing damaged organs, ...Duke Researchers Genetically Engineer Mice To Block Heart Enlargement
...etically engineered mice to produce a protein that acts as a molecular decoyto stop enlargement of the hea...he interior of the cell. There a protein called Gq acts like a relay station,receiving messages from many receptors and sending them on to the cell'snucleus......t the NDT80 gene encodes the critical protein that acts to stimulatethe synthesis of a set of proteins known as cyclins, which spark entry into DNAdivision. They also determined that the Ndt80 protein is responsible for thesynthesis of another set of proteins, which contribute to the unique shape ofthe s...... stellata) can break down lignin, the polymer that acts as a naturalbinder and support for cellulose fibers of woody plants. The potential use ofsuch bacteria in the pulp and paper industry is obvious. And lignin and relatedcompounds also have many natural sources in coastal waters. Also, there is...High-Altitude Cerebral Edema Likely Caused By Leaks In Blood-Brain Barrier
... messenger, cyclic guanosine monophosphate (cGMP), acts with nitric oxide, a vasodilator, to promote and sustain permeability of the blood-brain barrier. The combined influence of actions could allow fluid to accumulate in the intracellular spaces, he said. Yet another mechanism that may be at work ......is colleagues reported that thenormal CFTR protein acts as a receptor for P. aeruginosa and helps clear th...is colleagues showed that normal CFTR protein also acts as areceptor for Salmonella typhi, the gastrointestinal pathogen that causes typhoidfever. In tissu...