October 19, 2006, 8:43 PM CT
In Early Embryos, Cilia Get The Message
Having your heart in the right place commonly means having it located on the left side of your body. But just how a perfectly symmetrical embryo settles on what's right and what's left has fascinated developmental biologists for a long time. The turning point came when the rotational beating of cilia, hair-like structures found on most cells, was identified as essential to the process.
Now, researchers at the Salk Institute for Biological Studies take a step back and illuminate the molecular process that regulates formation of cilia in early fish embryos. As per a research findings published in a forthcoming issue of Nature Genetics, the Salk team, led by Juan Carlos Izpisa Belmonte, Ph.D., a professor in the Gene Expression Laboratory, identified a novel factor that links early developmental signals with the function of cilia and their role in controlling left-right specification in zebrafish.
"When we altered the function of the gene duboraya, we saw problems with cilia formation, eventhough the gene product itself is not a part of the structure. This opens up a new area of research," says Belmonte.
Cilia have been known to cell biologists for over a hundred years. Belmonte is convinced that these humble structures, which have until recently been ignored by physiologists and molecular biologists alike, are poised to take center stage in the field of biology. Explains Belmonte: "When you impair the function of cilia or the flow of cilia, you create substantial problems throughout the body."........
Posted by: Julia Permalink Source
October 18, 2006, 10:44 PM CT
Hospital food not good enough
Montclair, NJ - October 18, 2006 -- Substantial nutrient loss in food occurs in hospital foodservice operations, according to research recently published in the Journal of Foodservice. The study quantifies how much Vitamin C, as a marker of nutrient quality, is retained at various stages of processing at two New Jersey hospitals.
The nutrient quality of Vitamin C was significantly reduced as a food sample progressed to patients by as much as 86% at a hospital in an inner-city neighborhood. Since many nutrients, including Vitamin C, degrade at high temperatures, this loss may be result from food being heated to a temperature much higher than recommended by hospital foodservice so as to still be warm when served to patients.
As improved nutritional status correlates with faster healing and recovery, leading to reduced hospital stays, hospitals need improved cooking methods to reduce the loss of nutrients in foods served to patients. Physicians, dietitians, and menu planners rely on published standard nutritional values, but these standards are derived from experiments made in ideal conditions and fail to consider the various handling, holding, and delivery methods that are common in hospitals. A more vigorous approach to patient nutrition is needed, both in terms of food preparation methods and in assessing the actual nutritional status of patients.........
Posted by: Julia Permalink Source
October 17, 2006, 9:42 PM CT
New Research To Cut Animal Testing
Scientists at The University of Manchester have been awarded £130,000 to develop new techniques to reduce the need for animals in drug testing.
Current checks to establish whether a new drug is carcinogenic can be inconclusive and require further testing on live animals to establish whether they are harmful or not.
Dr Richard Walmsley and his colleagues at the University spin-out company he founded, Gentronix, have developed techniques using cultured human cells to more effectively weed out cancer-causing compounds.
"The current pre-animal tests that are used are highly sensitive and so most carcinogens are identified," said Dr Walmsley, who is based in the Faculty of Life Sciences.
"Unfortunately, such tests have poor specificity and a lot of safe compounds are also wrongly identified as potential carcinogens. This means that animal testing is still carried out, in case such compounds turn out to be safe.
"The testing process developed at Gentronix has proven very reliable at telling us whether a drug will cause cancer but some chemicals, called promutagens, only become carcinogenic once they have passed through the body's liver.
"This grant will help us develop new non-animal experiments to identify these other toxic compounds and so reduce the need for animal testing".........
Posted by: Julia Permalink Source
October 17, 2006, 9:22 PM CT
Virtual Colonoscopy saves lives
Image courtesy of Vision system
Three-dimensional computed tomography (CT) colonography, also known as virtual colonoscopy, is an accurate screening method for colorectal cancer, as per a research studyreported in the recent issue of the journal Radiology. In addition, when covered by third-party payers, virtual colonoscopy may entice more people to be screened.
"Our positive experience with virtual colonoscopy screening covered by health insurance demonstrates its enormous potential for increasing compliance for colorectal cancer prevention and screening," said lead author Perry J. Pickhardt, M.D., associate professor of radiology at The University of Wisconsin Medical School in Madison. "In addition, recent technical improvements have resulted in even better performance results".
Colorectal cancer remains the second leading cause of cancer mortality in the United States, and the American Cancer Society (ACS) estimates that there will be 148,610 new cases diagnosed in 2006 and 55,170 deaths. The disease is largely preventable through screening for colon polyps, which are non-malignant growths that may develop into cancer if not removed. ACS recommends that people at average risk for colorectal cancer begin regular colorectal cancer screening at age 50, but current compliance with this recommendation remains well below 50 percent. A number of people resist screening because of the discomfort and inconvenience caused by the standard optical colonoscopy test.........
Posted by: Julia Permalink Source
October 16, 2006, 10:06 PM CT
How Ebola And Marburg Cause Disease
Ebola Virus
Researchers in the Greene Infectious Disease Laboratory at Columbia University's Mailman School of Public Health, the Centers for Disease Control and Prevention, and the Caribbean Primate Research Center have discovered a key mechanism by which the Filoviruses, Ebola and Marburg, cause disease. The identification of an amino acid sequence in Filoviruses that results in the rapid depression of immunological response is described in the December 2006 issue of The FASEB Journal. Using this information, researchers can begin to develop new drugs to stop these devastating diseases.
Filoviruses, named for their threadlike appearance in electron microscopy (filo= thread in Latin), are associated with outbreaks of fatal hemorrhagic fever in sub-Saharan Africa. Viral hemorrhagic fevers are of specific concern because they are associated with high morbidity and mortality (up to 80% mortality rates) and the potential for rapid dissemination through human-to-human transmission. The term "viral hemorrhagic fever" characterizes a severe multisystem syndrome associated with fever, shock, and bleeding caused by infection with one of a number of viruses, including the Filoviruses Ebola and Marburg.
Both humans and apes are susceptible to viral hemorrhagic fevers, and it is speculated that filovirus infections account at least in part for the recent decline in the gorilla and chimpanzee population in central Africa. There is no cure or approved vaccine for either Marburg or Ebola virus. Immunosuppression occurs early after infection and allows the viruses to reproduce rapidly and cause disease.........
Posted by: Julia Permalink Source
October 16, 2006, 9:53 PM CT
Women On Hormone Therapy Sensitive To Negative Events
Older women on hormone treatment are more sensitive to negative events, confirming speculation that age-related estrogen loss affects the brain's ability to process emotion, an Oregon Health & Science University study shows.
But that sensitivity to negative emotional events, such as viewing a photograph of a dead person, doesn't necessarily mean women taking estrogen remember those events any better.
In the study by scientists in the Cognition & Aging Laboratory at the OHSU School of Medicine's Department of Behavioral Neuroscience, hormone treatment in women appears to reverse the age-related loss of arousal to negative emotional events experienced by the elderly. It also points to specific changes in the brain's arousal system, in the regions that process emotion, and intensification of negative emotions.
The results were presented today at Neuroscience 2006, the Society for Neuroscience's 36th annual meeting at the Georgia World Congress Center in Atlanta.
Researchers have suspected a link between sex hormones and emotion. Strengthening this theory is the fact that brain regions tuned for processing emotion and storing emotional memory - the amygdala and hippocampus - also respond to sex hormones and contain hormone receptors. Thus, changes in "emotional enhancement" people experience as they age, including a reduction in the ability to remember negative events, may be modified by age-related loss of sex hormones or hormone treatment.........
Posted by: Julia Permalink Source
October 15, 2006, 7:38 PM CT
Physicians Hinder Use Of Cutting Edge Technology In Diabetes
Diabetic patients who use newer technologies such as insulin pumps and blood glucose monitoring devices are better able to manage their disease and adhere to treatment regimens, with less daily pain, than with conventional treatments, according to Duke University researchers. Yet researchers have found that the newer methods to manage diabetes are not being widely used because physicians may be reluctant to prescribe them, and even patients who are using them may not be deriving their full benefits.
According to the Duke researchers, the lack of strong scientific evidence on the efficacy of newer devices, combined with insufficient patient-education resources for physicians and their patients, hinders the diffusion of new devices and contributes to their incorrect use. In addition, the researchers pointed to the higher costs of newer medical technologies and the demographics of diabetes as probable causes of low usage - i.e., its disproportionate prevalence among racial and ethnic minorities, persons of low socioeconomic status, and the elderly.
These findings have emerged from a literature review conducted by the Medical Technology Assessment Working Group at Duke University, focusing on technologies used to monitor glucose and deliver insulin outside of conventional methods, such as daily injections and finger stick tests.........
Posted by: Julia Permalink Source
October 15, 2006, 7:17 PM CT
Same Gene For Cleft Lip And Skin Biology
Following up on an earlier discovery that a gene called IRF6 is involved in the common birth defect cleft lip and palate, scientists at the University of Iowa Roy J. and Lucille A. Carver College of Medicine and their colleagues have identified the function of the gene. Their latest findings, published online Oct. 15 in Nature Genetics, reveal an unexpected role for IRF6 in the growth and development of skin cells, a discovery that may have implications for wound healing and cancer research.
In 2002, Brian Schutte, Ph.D., UI associate professor of pediatrics and nursing, and Jeff Murray, M.D., UI professor of pediatrics, pediatric dentistry and biological sciences, and the Roy J. Carver Chair in Perinatal Health, led a study showing that mutations in IRF6 cause Van der Woude syndrome (VWS), a rare, dominantly inherited form of cleft lip and palate. Subsequently, the scientists observed that this gene also is mutated in 10 to 15 percent of the more common, so-called non-syndromic cases of cleft lip and palate. Cleft lip and palate, where the lip or both the lip and palate (roof of the mouth) fail to close, occurs in approximately one of every 1,000 babies.
In order to determine the function of this gene, the scientists created mice that lacked IRF6. These mice had very abnormal skin as well as a cleft palate. Detailed analysis of the mice revealed that IRF6 regulates the proliferation and differentiation of keratinocytes -- the main cell type in the epidermis or outer layer of skin. Keratinocytes also provide a protective barrier around the mouth, gut, liver, lung, kidney and other internal organs.........
Posted by: Julia Permalink Source
October 15, 2006, 7:04 PM CT
Friendly Bacteria To Fight Food Allergies
Feeding babies alcoholic milk may help to protect against some food allergies. Kefir, a traditional fermented drink, is consumed in Eastern Europe as a health food, and is often used to wean babies, as it is easily digested. Food allergy prevalence is particularly high in children under the age of three, with around 5-8% of infants at risk. Currently the only therapy is avoidance of the problematic food.
"Friendly" bacteria in kefir may play a role in blocking the pathway involved in allergic responses, Lisa Richards reports in Chemistry & Industry, SCI's fortnightly magazine. Research published recently [Monday 16 October 2006(DOI 10.1002/jsfa2469)] in the SCI's Journal of the Science of Food and Agriculture has shown that the milk drink inhibits the allergen specific antibody Immunoglobulin E (IgE). IgE is involved in immune responses to inactivate organisms that might cause disease. However, in the presence of allergens it can also activate cells responsible for the release of histamine, a chemical which stimulates allergic responses, such as inflammation and constriction of airways.
Ji-Ruei Liu's team of researchers at the National Formosa University, Yunlin, Taiwan, fed mice the milky drink, and observed that after 3 weeks, the amount of ovalbumin (OVA) specific IgE was reduced three-fold. Ovalbumin is an allergenic protein found in egg whites, which cause most allergies in young children. Kefir is also reported to prevent food antigens from passing through the intestinal wall.........
Posted by: Julia Permalink Source
October 15, 2006, 6:41 PM CT
New Mechanisms For Dopamine Release
The neurotransmitter dopamine continues to be released for nearly an hour after neurons are stimulated, suggesting the existence of secondary mechanisms that allow for sustained availability of dopamine in different regions of the brain including areas critical for memory consolidation, drug induced plasticity and maintaining active networks during working memory, according to a University of Pittsburgh study being presented today at the 36th Annual Meeting of the Society for Neuroscience, held at the Georgia World Congress Center in Atlanta.
Determining the mechanisms that cause what is being called "post-stimulus activated release" and how they maintain dopamine levels could have important implications for understanding and treating neurological and psychiatric disorders caused by an imbalance of dopamine function including schizophrenia, attention deficit hyperactivity disorder, Tourette's syndrome, Parkinson's disease and addiction.
According to Bita Moghaddam, Ph.D., professor of neuroscience and psychiatry, who led the study, in addition to its clinical benefits, post-stimulus activated release can be used to explain how brief events that activate neurons for short periods of time can influence brain function long after the events. For example, it can be used to explain how smelling freshly baked cookies could evoke childhood memories of spending time with a beloved grandparent, leading a person to reminisce long after the smell is gone and take the unplanned or impulsive action of baking or buying cookies.........
Posted by: Julia Permalink Source
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