July 19, 2006, 10:29 PM CT

Breast Stem Cell Secrets

The most aggressive form of breast cancer may originate from breast stem cells that have undergone genetic mishaps.

Victorian Breast Cancer Research Consortium researchers from The Walter and Eliza Hall Institute, using mouse models, have discovered that breast stem cells do not express receptors for the female hormones oestrogen or progesterone. These and other features of the stem cell resemble the aggressive 'basal' subtype of breast cancer. There is increasing evidence that breast cancer is not simply a single disease. Researchers now view breast cancer as a heterogeneous disease, made up of various subtypes. This observation has led to speculation that breast tumours are derived from different cell types that could include the breast stem cell or its descendents that have suffered genetic accidents.

This possibility has generated great interest in understanding the composition of normal breast cells including the stem cell. A question of particular interest is whether the breast stem cell expresses receptors for oestrogen and progesterone and the marker 'Her2', since these help define the subtypes of breast cancer; and also guide current approaches to treatment.

The WEHI team, together with the Eaves group in Vancouver, have observed that the breast stem cell in mice is 'triple negative' for oestrogen, progesterone and Her2 receptors but does express certain 'basal cell' markers. These characteristics also define the basal subtype of breast cancer, which is more usually seen in tumours that develop in women who are carriers of the breast cancer predisposing gene BRCA1.........

Posted by: Janet      Permalink         Source

July 19, 2006, 10:08 PM CT

Antioxidants May Slow Vision Loss

Researchers at Johns Hopkins have successfully blocked the advance of retinal degeneration in mice with a form of retinitis pigmentosa (RP) by treating them with vitamin E, alpha-lipoic acid and other antioxidant chemicals.

"Much more work needs to be done to determine if what we did in mice will work in humans," said Peter Campochiaro, the Eccles Professor of Ophthalmology and Neuroscience at The Johns Hopkins University School of Medicine. "But these findings have helped to solve a mystery".

In patients with RP, rod photoreceptors die from a mutation, but it has not been known why cone photoreceptors die. After rods die, the level of oxygen in the retina goes up, and this work shows that it is the high oxygen that gradually kills the cones. Oxygen damage is also called "oxidative damage" and can be reduced by antioxidants. So for the first time, researchers have a therapy target in patients with RP, added Campochiaro. His team's findings appeared in the July online edition of the Proceedings of the National Academy of Sciences.

Retinas in all mammals, from mouse to man, are made up of light-sensitive cells known as cones and rods, named for their shapes, which convert light into nerve signals that are then transmitted to the brain via the optic nerve. Cones are needed to see colors and make vision possible in bright light, whereas the far more numerous rods permit sight in low light. The human retina contains approximately 125 million rod cells and six million cone cells. In diseases like RP and age-related macular degeneration (AMD), these cells die off and eventually lead to blindness (in the case of RP) or legal blindness (in the case of AMD).........

Posted by: Mike      Permalink         Source

July 19, 2006, 10:03 PM CT

Autism: Fewer Neurons For Processing Emotion

For the first time, research has shown that the autistic brain has fewer neurons in an area correlation to emotion and social behavior, as per a new study reported in the July 19 issue of The Journal of Neuroscience.

This study provides quantitative evidence linking autism to an abnormality of the amygdala, particularly the lateral nucleus-a major emotion-processing area with connections to parts of the brain responsible for higher cognitive functions.

"These new findings, based on cell counting, complement other independent studies that suggest amygdala abnormalities likely contribute significantly to the primary core deficit in social function that defines this disorder," says Emanuel DiCicco-Bloom, MD, professor of pediatric neurology at the University of Medicine and Dentistry of New Jersey.

Authors Cynthia Schumann, PhD, of the University of California, San Diego, and David Amaral, PhD, director of the M.I.N.D. Institute at the University of California, Davis, counted and measured neurons in the amygdala of nine postmortem autistic male brains and 10 age-matched male postmortem non-autistic brains. Ages ranged from 10 to 44 years old. Unlike prior postmortem studies, the sample excluded brains of individuals with epilepsy or similar disorders linked to cell loss in the amygdala.........

Posted by: JoAnn      Permalink         Source

July 19, 2006, 9:56 PM CT

Prevention Program For Childhood Obesity

The waistlines of children continue to grow, along with the concern about the problem. Two University of Cincinnati scientists are recruiting a school, parents and children in fighting obesity as they test a new prevention program in Meade County, Ky. After spending spring conducting focus groups with children and their parents, the 12-week program, geared toward 129 fifth-graders, will be launched at an elementary school in Brandenburg, Ky., when school begins this fall.

The obesity intervention program is the creation of Megan Canavera, a registered dietician and master's degree candidate in the program of health promotion and education, UC College of Education, Criminal Justice, and Human Services, and her advisor, Manoj Sharma, associate professor of health promotion and education.

The UC scientists are coordinating with the Brandenburg school's physical education teacher as they test the intervention program developed around four specific components:

• Regular physical activity.
• Enforcing healthy eating habits, such as limiting portion size, cutting soft drink consumption and adding fruits and vegetables to the children's diet.
• Cutting back on time watching TV.
• Improving parent-child communication to reinforce behaviors that cut back on obesity.
........

Posted by: JoAnn      Permalink         Source




July 19, 2006, 9:45 PM CT


Spinal Cord Stem Cell Transplantation is Safe

Hans Keirstead
Transplanting human embryonic stem cells does not cause harm and can be used as a therapeutic strategy for the therapy of acute spinal cord injury, as per a recent study by UC Irvine researchers.

UCI neurobiologist Hans Keirstead and his colleagues at the Reeve-Irvine Research Center observed that rats with either mild or severe spinal cord injuries that were transplanted with a therapy derived from human embryonic stem cells suffered no visible injury or ill effects as a result of the therapy itself. Furthermore, the study confirmed prior findings by Keirstead's lab - since replicated by four other laboratories around the world - that replacing a cell type lost after injury improves the outcome after spinal cord injury in rodents. The findings appear in the current issue of Regenerative Medicine.

"Establishing the safety of implanted embryonic stem cells is crucial before we can move forward with testing these therapys in clinical trials," said Keirstead, an associate professor of anatomy and neurobiology and co-director of UCI's Stem Cell Research Center. "We must always remember that a human clinical trial is an experiment and, going into it, we need to assure ourselves as best as we can that the therapy will not cause harm. This study is an important step in that direction".........

Posted by: Daniel      Permalink         Source




July 18, 2006, 9:09 PM CT


Calorie Restriction Better Than Exercise


Investigators at Washington University School of Medicine in St. Louis have observed that eating a low-calorie yet nutritionally balanced diet lowers concentrations of a thyroid hormone called triiodothyronine (T3), which controls the body's energy balance and cellular metabolism.

The scientists also observed that calorie restriction (CR) decreases the circulating concentration of a powerful inflammatory molecule called tumor necrosis factor alpha (TNFa). They say the combination of lower T3 levels and reduced inflammation may slow the aging process by reducing the body's metabolic rate as well as oxidative damage to cells and tissues.

Prior research on mice and rats has shown that both calorie restriction and endurance exercise protect them against a number of chronic diseases including obesity, diabetes, cardiovascular disease and some types of cancer. However, the research has shown that only CR increases the animals' maximum lifespan by up to 50 percent. These animal studies suggest that leanness is a key factor in the prevention of age-associated disease, but reducing caloric intake is needed to slow down aging.

For the new study, scientists examined 28 members of the Calorie Restriction Society who had been eating a CR diet for an average of six years. Eventhough the CR group consumed fewer calories - averaging only about 1,800 per day - they consumed at least 100 percent of the recommended daily amounts of protein and micronutrients. A second group of 28 study subjects was sedentary, and they ate a standard Western diet. A third group in the study ate a standard Western diet - approximately 2,700 calories per day - but also did endurance training. The scientists found reduced T3 levels - similar to those seen in animals whose rate of aging is reduced by CR - only in the people on CR diets.........

Posted by: Daniel      Permalink         Source




July 18, 2006, 9:01 PM CT


Earlier Use Leads To Better Speech

A cochlear implant's external component senses sound and sends electrical signals to an internal component that stimulates the hearing nerves in the inner ear.
"Bye-bye, bye-bye," said one 3 and a half-year old child, born deaf but with a cochlear implant that partially restored hearing nine months earlier. That's the most complex speech the child uttered during a testing session that involved play with a toy train set.

In contrast, a child of the same age who had a cochlear implant 31 months earlier made more sophisticated statements: "OK, now the people goes to stand there with that noise and now - Woo! Woo!" and "OK, the train's coming to get the animals and people."

The testing session was part of research that indicates the earlier a deaf infant or toddler receives a cochlear implant, the better his or her spoken language skills at age 3 and a half. The research was conducted by Johanna Grant Nicholas, Ph.D., research associate professor of otolaryngology at Washington University School of Medicine in St. Louis and colleague Ann E. Geers, Ph.D., from the Southwestern Medical School at the University of Texas at Dallas.

"Ninety percent of children born deaf are born to hearing parents, and these parents know very little about deafness," Nicholas says. "They don't know how to have a conversation in sign language or teach it to their children. A number of of these parents would like their children to learn spoken language."........

Posted by: Sue      Permalink         Source




July 18, 2006, 8:47 PM CT


World's First Handheld Electronic Reader For The Blind


The National Federation of the Blind (NFB) today unveils a groundbreaking new device, the Kurzweil-National Federation of the Blind Reader. The portable Reader, developed by the National Federation of the Blind and renowned inventor Ray Kurzweil, enables users to take pictures of and read most printed materials at the click of a button. Users merely hold "the camera that talks" over print-a letter, bills, a restaurant menu, an airline ticket, a business card, or an office memo-and in seconds they hear the contents of the printed document played back in clear synthetic speech. Combining a state-of-the-art digital camera with a powerful personal data assistant, the Reader puts the best available character-recognition software together with text-to-speech conversion technology-all in a single handheld device.

Marc Maurer, president of the National Federation of the Blind, said: "The world of the printed word is about to be opened to the blind in a way it has never been before. No other device in the history of technology for the blind and visually impaired has provided quicker access to more information. The NFB promotes a positive attitude towards blindness, and this Reader will make blind and visually impaired people dramatically more independent. The result will be better performance at work, at school, at home, and everywhere else we go. This Reader substantially improves the quality of life for the growing number of blind and visually impaired people".........

Posted by: Mike      Permalink         Source




July 18, 2006, 8:39 PM CT


Tumor Escapes From Attacks


Like the fictional wizard Harry Potter, some malignant tumors seem capable of wrapping themselves in an invisibility cloak. Scientists at Washington University School of Medicine in St. Louis have observed that pancreatic tumors hide from the body's immune surveillance by surrounding themselves with cells that make it hard for the immune system to detect them.

The tumor-protecting cells are white blood cells called regulatory T cells, or T-reg for short. Under ordinary circumstances, T-reg cells inhibit immune components responsible for killing unwanted cells - this allows T-reg cells to help prevent autoimmune reactions.

The researchers discovered that malignant cells take advantage of T-reg cells' suppressor ability, enlisting them to keep the immune system at bay. Their report appears in the July/recent issue of the Journal of Immunotherapy.

"Earlier, we observed that T-reg cells are much more prevalent in patients with breast cancer and pancreas cancer than in healthy patients," says David C. Linehan, M.D., associate professor of surgery and a researcher with the Siteman Cancer Center. "The new findings show that tumors are directly responsible for the increase of T-reg cells and can attract T-reg cells to their vicinity. This could be one way for tumors to evade immune surveillance."........

Posted by: Janet      Permalink         Source




July 18, 2006, 8:34 PM CT


New diabetes drug may also cause weight reduction

Cris Welling
The Washington University Diabetes Center at Barnes-Jewish Hospital focuses on providing patients with the latest technology, therapys and clinical research. Some patients at the center are receiving a new diabetes drug that may give a welcome side effect - weight loss.

Byetta, developed by Amylin Pharmaceuticals and Eli Lilly and Co., is designed to help patients with type 2 diabetes get better control of their condition by helping the body make more of its own insulin. The drug, a twice-daily injection, tells the pancreas to make the right amount of insulin after meals to bring blood sugar closer to normal levels. It also helps stop the liver from producing too much sugar when the body doesn't need it, and helps slow down the rate at which sugar enters the bloodstream. It is typically used along with oral diabetes medications, and in some patients, it has led to weight loss.

One of the patients taking Byetta is Cris Welling, a research lab supervisor in the endocrinology/metabolism lab of M. Alan Permutt, M.D., professor of medicine and of cell biology and physiology. About five years ago, Welling volunteered to be a non-diabetic control in a University research study. When she went through the initial tests, she found out she had pre-diabetes.

Welling's physician, Garry Tobin, M.D., associate professor of medicine and medical director of the diabetes center, had prescribed several other oral medications to treat her diabetes, but none helped her to lose weight. Since she began taking Byetta for type 2 diabetes about 10 months ago, she has lost about 40 pounds. She no longer needs medicine for hypertension and has reduced the medicine she takes for high cholesterol.........

Posted by: JoAnn      Permalink         Source