October 8, 2007, 9:36 AM CT
Nanoparticle drug delivery system
Eva Harth in her laboratory.
There are two aspects to creating an effective drug: finding a chemical compound that has the desired biological effect and minimal side-effects and then delivering it to the right place in the body for it to do its job.
With the support from a $478,000, five-year CAREER award from the National Science Foundation, Eva Harth is tackling the second part of this problem. She is creating a modular, multi-functional drug delivery system that promises simultaneously to enhance the effectiveness and reduce undesirable side-effects of a number of different drugs.
(NSFs Faculty Early Career Development awards are the agencys most prestigious honor for junior faculty members and are given to individuals judged most likely to become the academic leaders of the 21st century.).
Harth, who is an assistant professor of chemistry at Vanderbilt University, has created a nanosponge specially designed to carry large numbers of drug molecules. She has also discovered a molecular transporter that, when attached to the nanosponge, carries it and its cargo across biological barriers into specific intracellular compartments, which are very difficult places for most drugs to reach. She has shown that her system can reach another difficult target: the brain. Experiments have shown that it can pass through the brain-blood barrier. In addition, she has: successfully attached a special targeting unit that delivers drugs to the surface of tumors in the lungs, brain and spinal cord and even developed a light kit for her delivery system fluorescent tags that researchers can use to monitor where it goes.........
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October 8, 2007, 8:47 AM CT
Medicare modernization act and chemotherapy
Cancer patients receiving chemotherapy have not noticed a restriction in their access to therapy following the enactment of the Medicare Prescription Drug, Improvement and Modernization Act of 2003 (MMA), despite the act's significant reduction in government reimbursement to oncologists, as per a new study led by scientists in the Duke Clinical Research Institute (DCRI).
Critics of the MMA often said that it would reduce patients access to chemotherapy services, because doctors would receive 30 to 40 percent less reimbursement from the government for administering therapy, said Kevin Schulman, M.D., director of the DCRIs Center for Clinical and Genetic Economics, and senior investigator on the study. Our study showed that patients actually do not perceive barriers to their access to chemotherapy and perceptions about access are really the same among patients who received therapy before the legislation went into effect, and those who received it afterwards.
The team's findings would be reported in the November 15, 2007 print edition of the journal Cancer, but also will appear earlier in the journals October 8, 2007 online edition. The study was funded by a grant from the National Patient Advocate Foundations Global Access Project, which brings together 42 national healthcare stakeholder groups -- such as pharmaceutical companies and advocacy groups -- to fund health research projects. The Project has focused on examining the MMAs consequences for patients, providers and healthcare systems.........
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October 8, 2007, 8:32 AM CT
Limiting refined carbohydrates may stall AMD progression
Eating fewer refined carbohydrates may slow the progression of age-related macular degeneration (AMD), as per a new study from scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.
AMD results in partial or total blindness in 7 to 15% of the elderly, as per the Eye Diseases Prevalence Research Group. Dietary changes may be the most practical and cost-effective prevention method to combat progression of AMD, says Allen Taylor, PhD, director of the Laboratory for Nutrition and Vision Research at the USDA HNRCA. It is surprising there is so little attention focused on the relationship between AMD and carbohydrates.
The current study, reported in the recent issue of the American Journal of Clinical Nutrition, builds on a recent analysis by Taylor and his colleagues that found men and women older than 55 who consumed diets with higher-than-average dietary glycemic index foods appeared to have an increased risk for both early and later stages of AMD.
Dietary glycemic index is a scale used to determine how quickly carbohydrates are broken down into blood sugar, or glucose. Foods with a high glycemic index are linked to a faster rise and subsequent drop in blood sugar. Refined carbohydrates like white bread and white rice have high glycemic indices. Whole wheat versions of rice, pasta and bread are examples of foods with low glycemic indices.........
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October 8, 2007, 8:36 AM CT
Hip size of mothers linked to breast cancer in daughters
In a study of the maternity records of more than 6,000 women, David J.P. Barker, M.D., Ph.D., and Kent Thornburg, Ph.D., of Oregon Health & Science University discovered a strong connection between the size and shape of a womans hips and her daughters risk of breast cancer. Wide, round hips, the scientists postulated, represent markers of high sex hormone concentrations in the mother, which increase her daughters vulnerability to breast cancer.
A womans hips are shaped at puberty when the growth of the hip bones is controlled by sex hormones but is also influenced by the level of nutrition. Every woman has a unique sex hormone profile which is established at puberty and persists through her reproductive life. The studys findings show for the first time that the pubertal growth spurt of girls is strongly linked to the risk of breast cancer in their daughters.
The study, carried out with colleagues in Finland and the United Kingdom., is described in an article just published online by the peer-evaluated American Journal of Human Biology. The authors followed up on 6,370 women born in Helsinki from 1934 to 1944 whose mothers pelvic bones were measured during routine prenatal care. The study observed that breast cancer rates were more than three times higher among the women in the cohort, born at or after term, whose mothers had wide hips. They were more than seven times higher if those mothers had already given birth to one or more children.........
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October 8, 2007, 8:21 AM CT
Folic acid lowers blood arsenic levels
Folic acid and vitamin B12
A new study by scientists at Columbia University Mailman School of Public Health finds that folic acid supplements can dramatically lower blood arsenic levels in individuals exposed to arsenic through contaminated drinking water. This toxic element, naturally present in some aquifers used for drinking, is currently a significant public health problem in at least 70 countries, including several developing countries and also parts of the U.S. Chronic arsenic exposure is linked to increased risk for skin, liver and bladder cancers, skin lesions, cardiovascular disease, and other adverse health outcomes. The study results are reported in the recent issue of the American Journal of Clinical Nutrition.
The scientists observed that therapy with 400 micrograms a day of folic acid, the U.S. recommended dietary allowance, reduced total blood arsenic levels in the study population by 14 percent. Folate, a B vitamin found in leafy vegetables, citrus fruits, beans, and whole grains, can also be taken as a vitamin supplement, and in the U.S., is added to flour and other fortified foods. The scientists observed that folate deficiency is very common in Bangladesh, where the study was conducted.
Folic acid supplementation enhanced the detoxification of arsenic to a form that is more readily excreted in urine, said Mary Gamble, PhD, assistant professor of Environmental Health Sciences at the Mailman School, and lead author. The study is jointly supported by the National Institute of Environmental Health Sciences, part of the National Institutes of Health and the federally funded Superfund Basic Research Program (SPRB), which seeks solutions to the complex health and environmental issues linked to the nation's hazardous waste sites.........
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October 4, 2007, 9:45 PM CT
Swimming Babies And Infections
Photo: Immanuel Giel
Researchers of the GSF - National Research Center for Environment and Health (Helmholtz Association of German Research Centres) found indications for an association between attendance of swimming pools in the first year of life and the frequency of infections. Diarrhoea and otitis media during the first year of life are particularly noteworthy. No increased risks were found for atopic diseases during the first six years.
"In this way, the study shows that allowing babies to swim is possibly not as harmless with regard to infections as has been presumed till now," underlines Dr. Joachim Heinrich. He leads the research unit environmental epidemiology at the GSF Institute for Epidemiology.
Prof. Dr. Dr. H. Erich Wichmann, Director of the GSF Institute of Epidemiology, adds: "This is a first indication. Nevertheless, it requires other evidence to be able to achieve consequential results whether the water quality in German swimming-pools protects sufficiently against infections in infants, and, in particular, against gastro-intestinal infections".
Within the scope of the LISA study, a cohort study conducted from birth, 2,191 children were re-examined at age 6. Furthermore, the data of swimming-pool attendances during infancy were collated, while further data on children's health and life-style factors was collected by parental interviews.........
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October 4, 2007, 9:38 PM CT
Kids still not drinking enough milk
American children are drinking too little milk and what they are consuming is too high in fat, as per a Penn State study.
"There is a strong connection between dairy consumption and calcium," says Sibylle Kranz, assistant professor of nutritional sciences. "While there is calcium in fortified orange juice, for example, it is not as bioavailable as that found in milk." She notes that people need to take calcium with vitamin D and some protein for optimal use in the body.
Kranz, working with Po-Ju Lin, doctoral student and David A. Wagstaff, statistician, looked at children's average daily dairy intake and compared it with that recommended by the U.S. Department of Agriculture's My Pyramid dairy recommendations and Adequate Intake of calcium for various ages from 2 through 18. Their findings, reported online in press in the Journal of Pediatrics, are that only 2 to 3 year olds meet the MyPyramid dairy recommendations.
They also noticed that most children choose to consume more of the highest fat varieties of cheese, yogurt, ice cream and dairy-based toppings.
The various recommendations for dairy intake in children established by a variety of organizations suggest two cups for 1 to 3 year olds, two to three cups for 4 to 8 year olds, and three to four cups for 9 to 18 year olds depending on the recommending agency.........
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October 4, 2007, 9:35 PM CT
Cholesterol metabolism and Alzheimer's disease
Eventhough the causes of Alzheimer's disease are not completely understood, amyloid-beta (A-beta) is widely considered a likely culprit the "sticky" protein clumps into plaques thought to harm brain cells.
But now scientists at Washington University School of Medicine in St. Louis have uncovered evidence strengthening the case for another potential cause of Alzheimer's. The finding also represents the first time researchers have found a correlation between early- and late-onset Alzheimer's.
As per a research findings reported in the Oct. 4, 2007 issue of the journal Neuron, the researchers report that when A-beta is made, a small bit of protein is also released that can regulate cholesterol levels in the brain. The discovery adds weight to the less prominent theory that abnormal brain cholesterol metabolism plays a role in the mental decline seen in Alzheimer's patients.
"Our research links two major determinants for early- and late-onset Alzheimer's disease," says senior author Guojun Bu, Ph.D., professor of pediatrics and of cell biology and physiology. "And we've shown that the process that links them is implicated in brain cholesterol metabolism."
The report follows closely on another study reporting that statins, widely prescribed cholesterol-lowering drugs, could prevent certain neural changes that signal the progression of Alzheimer's disease. Additional earlier studies support the idea that statins could benefit Alzheimer's patients; however, other studies have observed no such protective effect from statins.........
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October 4, 2007, 9:13 PM CT
How Candida albicans transforms from its life-threatening form
Researchers at the Agency for Science, Technology and Research's (A*STAR) Institute of Molecular and Cell Biology (IMCB) have discovered new molecular mechanisms that provide a more detailed understanding of how the normally non-cancerous Dr. Jekyll-like fungus known as Candida albicans transforms into a serious and often life-threatening Mr. Hyde-like form.
C. albicans can cause serious and potentially life-threatening infections in the mouth, blood and other tissues of people who are undergoing cancer chemotherapy or radiation treatments, or who have developed AIDS or other diseases that damage the immunity of the individual.
In two separate papers published last month in Developmental Cell and in August in the EMBO journal, the team of scientists led by Wang Yue, principal investigator at IMCB, have managed to reveal previously unknown mechanisms which are responsible for causing the infectious phase of C. albicans.
The fungus starts its 'attack' on a patient by changing its oval shape into a filamentous form, which has thin, threadlike appendages emerging from the cell body. Wang's team, who has been studying C. albicans for more than seven years, was responsible for identifying the master "controller" protein called Hgc1 in 20041.
This "controller" functions like a regulator and tells the fungus when to start the transformation from the harmless oval shape to the infectious filamentous form.........
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October 4, 2007, 5:14 AM CT
Towards Early Cancer Detection
A test to detect the very early stages of cancer could one day result from new research by Cardiff University scientists.
A team at the University's School of Medicine has just published a study on telomeres - small structures at the end of human chromosomes which can play a crucial part in the onset of cancer.
Telomeres control cell division in the body - by gradually becoming shorter they can tell cells when it is time to stop dividing. However when telomeres stop working properly, they can cause the cells to mutate and start dividing uncontrollably, which can lead to the formation of tumours.
The Cardiff study used ground-breaking techniques to study telomeres in human cells. The scientists found the critical length at which telomeres stop working and also that some telomeres can be shortened or deleted at random, without any external cause.
The scientists also discovered how chromosomes can fuse together once they lose the protection of their telomeres. Chromosomal fusion causes the chromosomes to disintegrate, which can result in the development of malignant growths. The Cardiff study means there is now a system which can detect chromosomal fusions from single DNA molecules, opening up the possibility of an "early-warning" test for cancer.........
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