March 27, 2007, 9:37 PM CT

Fruit flyand human disease processes

Those small fruit flies buzzing around your bananas are more than peststhey may be allies in a fruitful search for clues to human diseases caused when genes malfunction.

"One common misconception is that individual humans may carry 'disease-causing' genes, such as a gene for cancer," explains James Erickson, a biology professor at Texas A&M University. "All humans have the same genes, but individual genes have different forms, called alleles, some of which may predispose an individual to a disease".

"Studying the common fruit fly Drosophilia melanogaster -- lets us conduct more sophisticated experiments than can be undertaken in humans. These simple organisms can be grown cheaply in test tubes, fed on yeast, corn meal and molasses, yet their embryos, which can be seen with the naked eye, undergo a number of of the same developmental processes as larger creatures. Thus, they can serve as models, allowing us to observe details we can't see in more complex animals".

To understand cellular differentiation, Erickson and his graduate students have been researching how fly embryos become male or female, a process that occurs over a 30-minute period early in their development and which is similar to the differentiation process for different types of cells, mirroring, for example, the way a liver cell becomes different from a blood cell......... Posted by: Emily      Read more         Source

March 27, 2007, 9:04 PM CT

Doubly safe activation

"Dual key" activation, in which two people must act in concert to launch a weapon, is often installed to safeguard highly destructive arms. New research at the Weizmann Institute of Science shows that cells may employ this strategy as well before launching certain potent weapons of the immune system.

Interferons, which were discovered 50 years ago, are the body's first line of defense against viral attack. They are produced in cells that have been invaded by viruses, and from there they spread out to warn other cells to prepare for the impending onslaught. These signaling molecules are linked to the symptoms fever and inflammation of viral infections such as the flu. Three main interferon families have been identified, and they are known by the Greek letters alpha, beta, and gamma. Interferons alpha and beta are very similar: they have nearly identical modes of action and even attach to the same receptor on the cell wall. However, interferon gamma is different. It has its own receptor and, in addition to its immediate antiviral actions, is involved in many crucial activities in the immune system, including a step known as antigen presenting, which enables the immune system to tailor antibodies to a specific enemy, and the activation of certain immune cells that engulf and destroy pathogens......... Posted by: Emily      Read more         Source

March 25, 2007, 9:27 PM CT

Simulated Populations For Gene Mapping

More powerful computers are allowing researchers and engineers to conduct simulations that grow more realistic each year. While companies are using these tools to slash the costs of producing everything from airliners to antibiotics, scientists in Houston are using them to refine their search for the genetic causes of disease.

In a new study published recently in the journal PLoS Genetics, statisticians and genetic epidemiologists from Rice University and The University of Texas M. D. Anderson Cancer Center used computer simulations to trace genetic changes over thousands of generations in a simulated population of hundreds of thousands of people. The goal: find out whether the tools that statistical geneticists use to pinpoint disease genes are up to the task of identifying multiple genes that cause complex diseases like cancer.

"In a real population, you never have the complete genetic picture, especially for complex diseases where more than one gene is implicated and where environmental factors play a role," said lead author Bo Peng of M. D. Anderson. "If we only see the people who get sick, we can never be sure how a number of people with the disease variant of the gene avoided getting sick. And there's always the question about how a number of people got the disease even though they didn't carry the variant"......... Posted by: Emily      Read more         Source

March 25, 2007, 9:20 PM CT

Ancestral Eve And Tooth Decay

A New York University College of Dentistry (NYUCD) research team has found the first oral bacterial evidence supporting the dispersal of modern Homo sapiens out of Africa to Asia.

The team, led by Page Caufield, a professor of cariology and comprehensive care at NYUCD, discovered that Streptoccocus mutans, a bacterium linked to dental caries, has evolved along with its human hosts in a clear line that can be traced back to a single common ancestor who lived in Africa between 100,000 and 200,000 years ago.

S. mutans is transmitted from mothers to infants, and first appears in an infants mouth at about two years of age. Caufields findings are reported in an article in the recent issue of the Journal of Bacteriology.

In his analysis of the bacterium, Caufield used DNA fingerprints and other biomarkers that researchers have also employed to trace human evolution back to a single common African ancestor, known as "ancestral Eve." .

"As humans migrated around the world and evolved into the different races and ethnicities we know today," Caufield said, "this oral bacterium evolved with them in a simultaneous process called coevolution." .

"It is relatively easy to trace the evolution of S. mutans, since it reproduces through simple cell division," says Caufield, who gathered over 600 samples of the bacterium on six continents over the past two decades. His final analysis focused on over 60 strains of S. mutans collected from Chinese and Japanese; Africans; African-Americans and Hispanics in the United States; Caucasians in the United States, Sweden, and Australia; and Amazon Indians in Brazil and Guyana......... Posted by: Emily      Read more         Source

March 25, 2007, 9:06 PM CT

Low-dose aspirin Vs high-dose aspirin

The use of medicines to fight cardiovascular disease has been a primary focus of research in this area for the past several decades, as combinations of interventions and medicinal therapy have gradually begun to increase long-term survival rates. Two studies presented today at the American College of Cardiology's 56th Annual Scientific Session look at the measurable impact of the use of aspirin and other maintenance therapies, and one demonstrates that lower doses of therapies may prove to be just as beneficial while also lowering side effects. ACC.07 is the premier cardiovascular medical meeting, bringing together cardiologists and cardiovascular specialists to further breakthroughs in cardiovascular medicine.

"Cardiovascular disease is the leading cause of death today, and the major focus of research is to find better ways to help these patients through prevention, immediate intervention and long-term treatment regimens," said Douglas P. Zipes, M.D., Distinguished Professor of the Indiana University School of Medicine. "As we continue to discover the benefits of these therapies, we expect to see continued and measurable improvements in overall survival and quality of life".

Effects of Aspirin dose on Ischemic Events and Bleeding after Percutaneous Coronary Intervention (PCI): Insights from the PCI-CURE Study (Presentation Number: 2805-9)......... Posted by: Emily      Read more         Source

March 25, 2007, 8:49 PM CT

Student-Dentists Helps Patients Quit Smoking

Students in most dental schools are taught to refer tobacco-using patients they encounter in their clinical training to call a "quit line".

The University at Buffalo's School of Dental Medicine is taking a different tack. In one of the few such programs in the nation, third- and fourth-year UB dental students are using non-judgmental tobacco counseling to encourage their patients to quit.

Results presented today (March 24, 2007) at the 2007 International Association of Dental Research meeting in New Orleans showed that 51 percent of the 89 patients who accepted and received tobacco counseling from the student-dentists agreed to quit immediately.

Of that number, 29 patients, or 32 percent, were still smoke-free after six months. Othman Shibly, D.D.S., UB assistant professor of periodontics and endodontics who developed the program, presented the findings.

"When I took over the responsibility for the dental school's preventive dentistry program," said Shibly, "I thought that major changes needed to be made in the dental curriculum to close the gap between clinical research and clinical practice.

"Students and dentists are taught about the effects of smoking on oral health but, in practice, we only do fillings and other procedures, so I led this effort to identify smoking as a dental problem that dentists should attend to......... Posted by: Emily      Read more         Source

March 25, 2007, 8:44 PM CT

Drug-eluting and bare-metal stents

Eventhough the use of stents to treat coronary artery disease has soared during the past decade thanks to novel equipment and new implant techniques, clinical data has recently raised concerns around the safety of drug-eluting stents (DES) and their risk of post-procedure complications. A study presented today at the American College of Cardiologys Innovation in Intervention: i2 Summit compared rates of complications in thousands of patients who received bare-metal stents (BMS) or DES. Innovation in Intervention: i2 Summit is an annual meeting for practicing cardiovascular interventionalists sponsored by the American College of Cardiology in partnership with the Society for Cardiovascular Angiography and Interventions.

Scientists from three University Hospitals in Western Denmark studied 12,395 stent patients; 11,730 coronary lesions were treated with BMS, and 5,422 lesions were treated with DES (CypherTM or TaxusTM). Both BMS and DES patients were treated with two types of blood-thinning medicines for 12 months following stent implantation, as recently recommended by the Food and Drug Administration (FDA). Scientists followed the patients for 15 months after stent implantation and assessed the rates of stent thrombosis, MI (myocardial infarction, or heart attack), mortality and revascularization (repeat procedure or bypass surgery to treat the target lesion)......... Posted by: Emily      Read more         Source

March 25, 2007, 8:31 PM CT

Dipstick test to reduce risk of food poisoning

Chemists at the University of South Carolina are developing a consumer test kit that people can use to quickly and accurately determine if food products are spoiled or safe to eat.

Described today at the 233rd national meeting of the American Chemical Society, the new diagnostic test, which researchers describe as a disposable dipstick, is capable of rapidly (less than 5 minutes) detecting the presence of chemicals formed by disease-causing bacteria. In preliminary studies, the test had a 90 percent accuracy rate, the researchers say. The test could help avoid illnesses and even deaths caused by food poisoning, which afflicts several million people each year in the United States alone.

The dipstick test is still in development but could be on store shelves in two to three years, says study leader John J. Lavigne, Ph.D., an assistant professor in the schools Department of Chemistry and Biochemistry, located in Columbia, S.C.

Theres no other test like this targeting the consumer market right now that I am aware of, says Lavigne. It has the potential to change the way individual diners think about the quality of their food and greatly impact public health.

Lavigne envisions that consumers will be able to carry the dipsticks with them and use them anywhere, including homes and restaurants......... Posted by: Emily      Read more         Source

March 25, 2007, 7:42 PM CT

Crestor could halt early atherosclerosis

An international study using ultrasound technology has found that the most potent cholesterol-lowering drug is also effective at halting early changes in the blood vessels that can lead to atherosclerosis.

"Rosuvastatin arrested the progression of thickened carotid arteries compared to a placebo," said John R. Crouse, M.D., lead researcher and a professor of endocrinology at Wake Forest University School of Medicine. "The findings show that the benefits of cholesterol management on arteries can be extended to low-risk patients".

Results from the study were reported today at the annual meeting of the American College of Cardiology in New Orleans and were published on-line by the Journal of the American Medical Association. The research involved people with moderately elevated cholesterol levels who didn't qualify for treatment under national guidelines.

Participants all had minimal thickening of their carotid arteries, which supply blood to the brain, and were considered at low risk for having a heart attack or dying from a heart-related event based on their age and other risk factors.

Over a two-year period, the therapy lowered low-density lipoprotein, or "bad" cholesterol, by 49 percent and increased high density lipoprotein, or "good" cholesterol, by 8 percent. Triglycerides were reduced by 16 percent and the progression of artery thickness was halted......... Posted by: Emily      Read more         Source

March 22, 2007, 10:25 PM CT

Natural polyester makes new sutures stronger

With the help of a new type of suture based on MIT research, patients who get stitches may never need to have them removed.

A biopolymer suture cleared last month by the FDA is made of materials that the human body produces naturally, so they can be safely absorbed once the wound is healed. They are also 30 percent stronger than sutures now used and very flexible, making them easier for surgeons to work with.

The sutures were developed by Tepha, Inc., a Cambridge company that hopes to use the same material to produce an array of absorbable medical devices, including stents, surgical meshes and possibly a heart valve scaffold, says Simon Williams, CEO of Tepha and a former MIT postdoctoral associate.

Williams said he envisions that the new sutures will be used for abdominal closures, which are prone to re-opening, and to stitch tendons and ligaments.

Developed using a method created at MIT, the absorbable sutures are the first made from material produced by genetically modified bacteria.

About 20 years ago, scientists in the laboratory of MIT biology professor Anthony Sinskey started swapping genes between different bacteria, hoping to achieve industrial production of desirable natural compounds synthesized by those bacteria.

The scientists focused their "biopolymer engineering" efforts on a group of genes that code for enzymes in a pathway that produces polyesters. Those polyesters can be broken down into metabolites naturally produced by humans, so they cause no harm when absorbed......... Posted by: Emily      Read more         Source