May 22, 2008, 10:01 PM CT
More Intensive Dialysis Does Not Improve Outcomes
No significant difference in death rates or other outcomes was found between a group of patients with acute kidney injury that received intensive dialysis and another group that received a more standard regimen of dialysis, as per a joint Department of Veterans Affairs (VA) and National Institutes of Health (NIH) study reported in the recent issue of the New England Journal (NEJM). Acute kidney injury, also called acute renal failure, is a common complication in hospitalized patients that is linked to very high mortality rates. In-hospital mortality rates of critically-ill patients typically range from 50 percent to 80 percent.
Several previous single-center studies in patients with acute kidney injury had suggested improved survival with more intensive dialysis, which is significantly more costly to administer. "We now have definitive evidence that intensive therapy of acute kidney injury is no more beneficial in improving therapy outcomes than the usual level of care," said NIH Director Elias A. Zerhouni, M.D. "As a result, the findings of this well-designed study may help prevent unnecessary medical expenditures."
Within 60 days after starting dialysis, 302 patients (53.6 percent) in the intensive therapy group died in comparison to 289 patients (51.5 percent) in the less-intensive therapy group. Also, the study reports no significant differences between the two groups in recovery of kidney function, the rate of failure of organs other than kidneys, or the number of patients able to return to their previous living situations.........
Posted by: Mark Read more Source
May 22, 2008, 9:51 PM CT
Gene may shed light on neurological disorders
In our brains, where millions of signals move across a network of neurons like runners in a relay race, all the critical baton passes take place at synapses. These small gaps between nerve cell endings have to be just the right size for messages to transmit properly. Synapses that grow too large or too small are linked to motor and cognitive impairment, learning and memory difficulties, and other neurological disorders.
In a finding that sheds light on this system, scientists at the University of Wisconsin-Madison describe a gene that controls the proper development of synapses, which could help explain how the process works and why it sometimes goes wrong.
Reporting today in the journal Neuron, a team of geneticists in the College of Agricultural and Life Sciences reveal the role of a gene in fruit flies called "nervous wreck" that prevents synapses from overgrowing by damping the effects of a pro-growth signal. Mutations in a human version of "nervous wreck" have been associated with a severe genetic developmental disability, and these findings may eventually help researchers develop therapys for this and other neurological disorders.
"The precise regulation of synaptic growth - not too much and not too little - is a complex biological process," says Kate O'Connor-Giles, a postdoctoral fellow in the genetics department who led the study. "We really need to have a deep understanding of how all the factors involved are working together to develop rational therapys for neurological disorders linked to aberrant synaptic growth".........
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May 21, 2008, 9:53 PM CT
Virtual biopsy for colon polyp
A probe so sensitive that it can tell whether or not a cell living within the human body is veering towards cancer development may revolutionize how future colonoscopies are done, say scientists from the Mayo Clinic in Jacksonville, Fla.
Investigators have observed that technology known as a high resolution confocal endomicroscopy probe system can determine whether a colon polyp is non-malignant (not premalignant) - without having to remove it for examination by a pathologist.
Their study, to be presented at the Digestive Disease Week, a scientific meeting of gastrointestinal specialists and scientists held in San Diego, shows that using the probe system was 89 percent accurate in identifying whether polyps were either premalignant or benign. But more importantly, it was correct 98 percent of the time in flagging polyps that were benign, which would then not need to be removed for biopsy. The Mayo researchers, who are the first in the U.S. to comprehensively test the system in the colon, believe they can push accuracy close to 100 percent with more research.
What this means is that the probe system can be used to during a colonoscopy to rule out removal of polyps that are not harmful, says the study's senior author, Michael Wallace, M.D., M.P.H., Professor of Medicine at Mayo Clinic.........
Posted by: Sue Read more Source
May 21, 2008, 8:57 PM CT
How common vaccine booster works
In an online paper in the journal Nature, Yale University scientists funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, explain how a common ingredient in a number of vaccines stimulates and interacts with the immune system to help provide protection against infectious diseases.
Vaccines must possess not only the bacterial or viral components that serve as targets of protective immune responses, but also ingredients to kick start those immune responses. In a number of vaccines, the bacterial or viral components themselves have this capability. For other vaccines, the immune system requires an added boost. Adjuvants are those substances added to a vaccine to help stimulate the immune system and make the vaccine more effective.
Currently the only vaccine adjuvants licensed for general use in the United States are aluminum hydroxide/phosphate formulations, known as alum. Eventhough alum has been used to boost the immune responses to vaccines for decades, no one has known how it worked.
In this paper, the Yale team, led by Richard Flavell, M.D., Ph.D., and Stephanie Eisenbarth, M.D., Ph.D., examined the immune system pathway and cell receptors used by alum. A number of microbial compounds function as adjuvants by stimulating Toll-like receptors. These receptors identify microbial invaders and alert the body to the presence of a disease-causing agent, or pathogen. Alum, however, does not stimulate Toll-like receptors. The Yale team observed that alum stimulates clusters of proteins called inflammasomes, found inside certain cells. Inflammasomes respond to stresses such as infection or injury by releasing immune cell signaling proteins called cytokines. Inflammasomes are a component of the innate immune system that operates in parallel with, but separate from, Toll-like receptors, also part of the innate immune system.........
Posted by: Scott Read more Source
May 21, 2008, 8:50 PM CT
Deceptive high-risk breast tumors
A unique genetic signature can alert physicians to high-risk breast tumors that are masquerading as low-risk tumors, as per research at Washington University School of Medicine in St. Louis and collaborating institutions. Eventhough these tumors are apparently estrogen-receptor positive meaning they should depend on estrogen to grow they don't respond well to anti-estrogen treatment.
Until now, doctors had no way to know these tumors would be unresponsive because their pathology is deceptive the tumors appear to be more easily treatable estrogen-receptor-positive tumors, but they rapidly lose their estrogen receptors. The scientists demonstrated that the chance for cancer recurrence in such patients is significantly higher, and standard post-operative care with long-term anti-estrogen treatment is often not effective. The genetic signature defined by the scientists will permit doctors to identify their high-risk patients and direct them to more effective treatment.
"These tumors are like wolves in sheep's clothing," says Matthew Ellis, M.D., Ph.D., associate professor of medicine in the Division of Medical Oncology and a faculty member at the Siteman Cancer Center. "When these patients come in, their tumors test positive for estrogen receptors, so they are started on anti-estrogen therapy with the thought that they will do fine. But these tumors don't depend on estrogen at all for growth and will keep growing during the treatment. Now we have a robust way to identify such tumors soon after diagnosis".........
Posted by: Janet Read more Source
May 21, 2008, 8:29 PM CT
Genetics of fat storage in cells
New research by the Gladstone Institutes of Cardiovascular Disease (GICD) and the University of California, San Francisco (UCSF), has revealed the genetic determinants of fat storage in cells, which may lead to a new understanding of and potential therapys for obesity, diabetes, and heart disease. While researchers have long understood that lipid droplets contribute to fat build up in cells, the genes involved in droplet biology have been a focus of extensive research.
As per a research findings published in Nature, researchers in the laboratories of Drs. Robert V. Farese, Jr., of Gladstone and UCSF, and Peter Walter, of UCSF, devised a genetic screen to identify genes responsible for fat storage in cell of fruit flies, and potentially other species.
For some time, we have been studying the enzymes that make fats, said Dr. Farese, senior investigator. But clearly, we need to know a lot more about the most basic processes that regulate cellular fat storage to be able to make progress on some very serious human diseases.
To identify novel genes involved in fat storage, GICD scientist Dr. Yi Guo, and Dr. Tobias Walter, formerly of Dr. Walters laboratory and now of the Max Planck Institute of Biochemistry in Gera number of, initiated a major discovery project, in which they used RNAi screens to individually inactivate all the genes in cells from fruit flies. Basic cellular processes in humans are highly conserved in cells from fruit flies, so the results should mostly be applicable to human biology. Drs. Guo and Walther completed the initial survey and have now begun to study in detail the genes that have the most striking effects on fat storage in cells.........
Posted by: JoAnn Read more Source
May 20, 2008, 10:58 PM CT
Incense is psychoactive: Biology behind the ceremony
Religious leaders have contended for millennia that burning incense is good for the soul. Now, biologists have learned that it is good for our brains too. In a new study appearing online in The FASEB Journal (http://www.fasebj.org), an international team of scientists, including scientists from Johns Hopkins University and the Hebrew University in Jerusalem, describe how burning frankincense (resin from the Boswellia plant) activates poorly understood ion channels in the brain to alleviate anxiety or depression. This suggests that an entirely new class of depression and anxiety drugs might be right under our noses.
In spite of information stemming from ancient texts, constituents of Bosweilla had not been investigated for psychoactivity, said Raphael Mechoulam, one of the research studys co-authors. We observed that incensole acetate, a Boswellia resin constituent, when tested in mice lowers anxiety and causes antidepressive-like behavior. Apparently, most present day worshipers assume that incense burning has only a symbolic meaning.
To determine incenses psychoactive effects, the scientists administered incensole acetate to mice. They observed that the compound significantly affected areas in brain areas known to be involved in emotions as well as in nerve circuits that are affected by current anxiety and depression drugs. Specifically, incensole acetate activated a protein called TRPV3, which is present in mammalian brains and also known to play a role in the perception of warmth of the skin. When mice bred without this protein were exposed to incensole acetate, the compound had no effect on their brains.........
Posted by: JoAnn Read more Source
May 20, 2008, 10:05 PM CT
Missed childhood vaccinations
Georgia Tech associate professor Pinar Keskinocak, graduate student Faramroze Engineer and executive secretary of the Advisory Committee on Immunization Practices of the CDC Larry Pickering (left to right) display the new online tool they developed that allows parents and pediatricians to ensure that the missed vaccines and future vaccines are administered without violating guidelines regarding vaccines and doses.
Credit: Georgia Tech Photo: Gary Meek
A new downloadable software tool will help pediatricians, parents and other health care professionals determine how to adjust complex childhood immunization schedules when one or more vaccine doses arent received at the proper time.
Children usually miss recommended times to receive vaccines. A report issued last month by the Centers for Disease Control and Prevention (CDC) found an alarming 28 percent of toddlers have not been vaccinated as per U.S. guidelines. Another recent survey observed that only nine percent of children received all of their vaccinations at the recommended times and that only half received all recommended doses by their second birthday.
Once a child falls behind in the vaccination schedule, health care professionals are left to figure out when its appropriate to give any missed vaccines and any future vaccines. They typically have to construct a unique, personalized catch-up schedule for each child often while the child sits in the therapy room.
Scientists at the Georgia Institute of Technology are taking the guesswork out of developing individualized catch-up vaccination schedules. A new online tool allows parents and pediatricians to ensure that the missed vaccines and future vaccines are administered without violating guidelines regarding vaccines and doses.........
Posted by: JoAnn Read more Source
May 20, 2008, 9:58 PM CT
Do chemicals in the environment affect fertility?
Our day-to-day exposure to chemicals is on the increase. From food packaging to the air we breathe, every day contact with potentially-toxic substances could be affecting our health - and our fertility.
Scientists at The University of Nottingham are set to take part in one of the first studies of the effect of environmental chemicals on female mammals. Part of the Reproductive Effects of Environmental Chemicals in Females Consortium (REEF), Dr Richard Lea of the School of Veterinary Medicine and Science and Dr Kevin Sinclair of the School of Biosciences will receive a £500,000 grant for their work researching how these chemicals impact on mammalian fertility. REEF will receive a total of £2.4m in funding from the EU.
Dr Lea and Dr Sinclair will study the impact of low levels of environmental chemicals on sheep foetuses in the womb. The specific chemicals to be studied are found in human sewage sludge which is frequently spread on fields where sheep graze previous to entering the human food chain.
The amount of chemicals absorbed is believed to be so minute that they would be difficult to discern through testing. However, through a process known as bioaccumulation, chemicals can become concentrated in individuals over many years, stored mostly in fat tissue. Though these chemicals may not be directly harmful to these individuals, if they are passed on - for example, through gestation in the womb or through the food chain - they might have consequences for human health.........
Posted by: Emily Read more Source
May 20, 2008, 9:53 PM CT
Determining genetic signature of lung tumors
The first U.S. clinical trial using genetic screening to identify lung tumors likely to respond to targeted therapies supports the use of those drugs as first-line therapy rather than after standard chemotherapy has failed. While the study led by Massachusetts General Hospital Cancer Center researchers observed that upfront gefitinib (Iressa) therapy considerably improved the outcomes for non-small-cell-lung-cancer (NSCLC), additional research is mandatory before such a strategy can be used for routine therapy planning. The report appears in the May 20 Journal of Clinical Oncology.
This is a pivotal clinical trial that demonstrates the power of personalized medicine in lung cancer therapy, says Lecia Sequist, MD, MPH, of the MGH Cancer Center, who led the study. It is an exciting glimpse into what we hope is the future of cancer care. Instead of a one size fits all treatment, we are moving towards finding the best therapy for each patient.
The most common form of lung cancer, NSCLC is the leading cause of cancer deaths in the U.S. Until recently, there were no therapy options for NSCLC patients in whom chemotherapy failed. Iressa, which disables the epidermal growth factor receptor (EGFR) on the surface of lung cancer cells, was approved in 2003 for therapy of NSCLC even though it shrank tumors in less than 15 percent of patients because, in those whom it did help, responses were rapid and dramatic.........
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