October 15, 2007, 4:43 PM CT
First colonoscopy with removal of polyps
Using a model to predict reductions in death from colorectal cancer, epidemiologists and clinical scientists from Memorial Sloan-Kettering looked at the relative effect of an initial screening colonoscopy which clears pre-malignant polyps from the colon versus surveillance follow-up colonoscopy. Ann G. Zauber, Ph.D., Sidney J. Winawer, M.D., MACG and his colleagues presented their findings at the Annual Scientific Meeting of the American College of Gastroenterology.
The model demonstrated a dramatic reduction in expected colorectal cancer mortality with initial polypectomy with or without surveillance, and suggests that the initial polypectomy accounts for the major component of the mortality reduction, explained Dr. Zauber.
Using a MISCAN model, scientists used National Polyp Study data to predict colorectal cancer mortality among three groups of patients: those with no initial removal of polyps or follow-up surveillance by colonoscopy, in comparison to patients with only initial polypectomy, and those with both polypectomy and follow-up surveillance. The model predicted mortality of up to thirty years after the initial colorectal exam and removal of pre-malignant polyps.
As per Dr. Zauber, the major effect on colorectal cancer mortality reduction produced by the initial polypectomy rather than the surveillance colonoscopies is consistent with the low occurence rate of advanced adenomas observed during National Polyp Study (NPS) follow-up (i.e., pre-malignant growths in the colon larger than 1 cm, polyps with a villous component, high grade dysplasia or invasive colorectal cancer.)........
Posted by: Sue Read more Source
October 15, 2007, 4:40 PM CT
Simple eye scan opens window to multiple sclerosis
A five-minute eye exam might prove to be an inexpensive and effective way to gauge and track the debilitating neurological disease multiple sclerosis, potentially complementing costly magnetic resonance imaging to detect brain shrinkage - a characteristic of the diseases progression.
A Johns Hopkins-based study of a group of 40 multiple sclerosis (MS) patients used a process called optical coherence tomography (OCT) to scan the layers of nerve fibers of the retina in the back of the eye, which become the optic nerve. The process, which uses a desktop machine similar to a slit-lamp, is simple and painless. The retinal nerve fiber layer is the one part of the brain where nerve cells are not covered with the fat and protein sheathing called myelin, making this assessment specific for nerve damage as opposed to brain MRI changes, which reflect an array of different types of tissue processes in the brain.
Results of the scans were calibrated using accepted norms for retinal fiber thickness and then in comparison to an MRI of each of the patients brains - also calibrated using accepted norms. Experimenters found a correlation coefficient of 0.46, after accounting for age differences. Correlation coefficients represent how closely two variables are related -- in this case MRI of the brain and OComputerized axial tomography scans. Correlation coefficients range from -1 (a perfect opposing correlation) through 0 (no correlation) to +1 (a perfect positive correlation). In a subset of patients with relapsing remitting MS, the most common form of the disease, the correlation coefficient jumped to 0.69, suggesting an even stronger association between the retinal measurement and brain atrophy.........
Posted by: Daniel Read more Source
October 12, 2007, 5:12 AM CT
Rejection sets off alarms for folks with low self-esteem
Researchers used paintings to stimulate a variety of emotions, with the paintings reflecting (clockwise from top left) inclusion, rejection, positive and negative themes.
Few can tolerate such romantic or professional rebuffs as "It's not you, it's me" and "we regret to inform you that your application was not successful." But while a healthy dose of self-esteem can absorb the shock of rejection, poor self-esteem can trigger the primal fight-or-flight response, as per a new study from the University of California, Berkeley.
That doesn't mean people with low self-esteem are doomed to respond defensively to criticism and rejection. The UC Berkeley study suggests that those among them who are better at controlling their impulses are less vulnerable to rejection. This lays the groundwork for further investigation into what people who feel they don't measure up can do to cope with disappointment and maintain close relationships.
"Social rejection is inevitable in society," said Anett Gyurak, a graduate student who co-authored the study with Ozlem Ayduk, a UC Berkeley assistant professor of psychology. "But our findings suggest that if people with low self-esteem can improve their attention control skills, they might feel less terrible about themselves and counter the negative effects of rejection."
While remedies to improve attention control require further study, scientists speculate that training the mind to focus for extended time periods and behavioral treatment that teaches people with low self-esteem to take a more positive or contextual approach to disappointment may help.........
Posted by: JoAnn Read more Source
October 12, 2007, 5:09 AM CT
Molecules that block cancer cells from modifying cell DNA
Scientists have discovered new small molecules that may prevent prostate cancer cells from turning off normal genes in a process that transforms normal cells into cancer cells. This significant discovery in the field of epigenetics has immediate implications in the development of new diagnostic tests and cancer medications. The findings were presented today at the Prostate Cancer Foundations annual Scientific Retreat. Funding for the research was provided by the Prostate Cancer Foundation, as well as from the National Cancer Institute and the Avon Foundation.
Epigenetics refers to changes to genes other than changes to the DNA sequence itself, such as the addition of molecules to the DNA strand. While the development of cancer can arise from defective or mutated genes, it can also arise from these changes that can actually prevent a cell from acting as it should. Cancer cells exploit this process, putting some genes in cold storage or turned off by modifying the cell DNA in a process known as methylation.
Lead researcher William Nelson, M.D., Ph.D., Professor of Oncology and Urology at the Johns Hopkins Kimmel Cancer Center, explained the findings. One of the proteins in the cell that triggers this process is called a methyl-CpG binding protein, or MBD. We have discovered an antagonist of MBD2 that keeps this protein from binding to methylated genes. If the protein cant bind to the gene, then it cant keep the gene turned off and the gene is turned back on able to act in the way it is supposed to.........
Posted by: Janet Read more Source
October 12, 2007, 5:00 AM CT
Anticlotting drug safe in sickle cell patients
An intravenous blood thinner widely used in patients with acute coronary syndromes and during coronary artery stent placement appears to be safe in patients with sickle cell disease and may have beneficial anti-inflammatory effects, a small study at the University of North Carolina at Chapel Hill School of Medicine has found.
We have tested a potentially promising drug in sickle cell patients, and the drug appears to be well tolerated. This gives us the impetus to go ahead with further studies of eptifibatide in these patients, said Dr. Leslie V. Parise, department chair and professor of biochemistry and biophysics at the UNC-Chapel Hill School of Medicine.
The hallmark of sickle cell disease is malformed red blood cells that can cause sudden painful episodes when they block small blood vessels. However, sickle cell patients are also at increased risk of developing multiple other complications, including strokes, lung complications and pulmonary hypertension.
The most frequent manifestations of sickle cell disorders are anemia and pain episodes. The episodic exacerbation of pain, often called crises, is unpredictable and may occur often in some patients.
The only drug presently approved for the therapy of sickle cell disease is hydroxyurea, which has been shown to reduce the frequency of painful episodes.........
Posted by: Scott Read more Source
October 12, 2007, 4:58 AM CT
Patients can't recall their medications to tell doctors
Doctors rely on patients to accurately tell them what prescription medications and what dosages -- they are taking in out-patient visits. (A patient's chart may not always be available or complete.) That information is essential for physicians to monitor whether a drug is working, and whether it may have adverse interactions with any new medications prescribed.
Depending on patients recall of their drugs, however, may be dangerous to their health.
New research from Northwestern Universitys Feinberg School of Medicine has observed that nearly 50 percent of patients taking antihypertensive drugs in three community health centers were unable to accurately name a single one of their medications listed in their medical chart. That number climbed to 65 percent for patients with low health literacy.
It was worse than we expected, said lead author Stephen Persell, M.D., an assistant professor of medicine, and of the Institute for Healthcare Studies at the Feinberg School, and a doctor at Northwestern Memorial Hospital. It means doctors cant ask patients to tell them the medications they are taking for their chronic conditions like hypertension. Its very hard to get at the truth of what medications the patient is actually taking.
The study would be reported in the recent issue of the Journal of General Internal Medicine.........
Posted by: Janet Read more Source
October 11, 2007, 10:53 PM CT
Welders at risk for loss of sense of smell
PHILADELPHIA Scientists at the University of Pennsylvania School of Medicine have observed that professional welders who work in enclosed spaces with poor ventilation may be at risk for loss of sense of smell. The study appears in Neurology.
This is the first study to clearly demonstrate that welders who work in confined spaces without adequate respiratory protection are at risk for damaging their sense of smell, says Richard Doty, PhD, Director, Smell & Taste Center, Professor, Department of Otorhinolaryngology, and senior study author. Eventhough underappreciated, loss of smell function significantly alters quality of life. This important sense not only determines the flavors of foods and beverages, but serves as an early warning system for the detection of fire, dangerous fumes, leaking gas, spoiled foods, and polluted environments.
Using the University of Pennsylvania Smell Identification Test (UPSIT) a self-administered standardized test incorporating 40 scratch-and-sniff odors with multiple choice options to identify the odor the scientists quantitatively reviewed the olfactory function of 43 professional welders who worked in confined spaces on the San Francisco/Oakland Bay Bridge, and compared their test scores with those of matched normal controls.........
Posted by: Janet Read more Source
October 11, 2007, 10:29 PM CT
Why some prostate cancer recurs after treatment
Cancer scientists have long worked to understand why some prostate cancers recur after the use of therapies designed to stop the production of testosterone and other androgens that fuel cancer cell growth. New research has now detected that androgen-synthesizing proteins are present within cancer cells, which suggests that cancer cells may develop the capacity to produce their own androgens.
The presence of these proteins may explain why some prostate cancers become resistant to these widely-used therapies, and offers new directions for research into future therapys that could block the development of androgens in the cancer cells. The study, funded by the Prostate Cancer Foundation and the National Cancer Institute, was presented today at the Foundations annual Scientific Retreat.
Androgen-deprivation treatment is routinely used in the therapy of advanced (metastatic) prostate cancer, in order to deprive cancer cells of these hormones that fuel their growth. However, over time cancer cells can become androgen independent, and grow even in the presence of these medications. This type of the cancer is a lethal form of the disease, with most patients dying 18 to 24 months after becoming resistant to hormone suppression. Research in the field has focused on understanding the mechanisms used by these cancer cells to become castration resistant.........
Posted by: Mark Read more Source
October 10, 2007, 6:49 PM CT
MIT finds new hearing mechanism
MIT scientists have discovered a hearing mechanism that fundamentally changes the current understanding of inner ear function. This new mechanism could help explain the ear's remarkable ability to sense and discriminate sounds. Its discovery could eventually lead to improved systems for restoring hearing.
The research is described in the advance online issue of the Proceedings of the National Academy of Sciences the week of October 8.
MIT Professor Dennis M. Freeman, working with graduate student Roozbeh Ghaffari and research scientist Alexander J. Aranyosi, observed that the tectorial membrane, a gelatinous structure inside the cochlea of the ear, is much more important to hearing than previously thought. It can selectively pick up and transmit energy to different parts of the cochlea via a kind of wave that is different from that usually linked to hearing.
Ghaffari, the lead author of the paper, is in the Harvard-MIT Division of Health Sciences and Technology, as is Freeman. All three scientists are in MIT's Research Laboratory of Electronics. Freeman is also in MIT's Department of Electrical Engineering and Computer Science and the Massachusetts Eye and Ear Infirmary.
It has been known for over half a century that inside the cochlea sound waves are translated into up-and-down waves that travel along a structure called the basilar membrane. But the team has now observed that a different kind of wave, a traveling wave that moves from side to side, can also carry sound energy. This wave moves along the tectorial membrane, which is situated directly above the sensory hair cells that transmit sounds to the brain. This second wave mechanism is poised to play a crucial role in delivering sound signals to these hair cells.........
Posted by: Sue Read more Source
October 10, 2007, 5:49 PM CT
Obesity boosts oesophageal cancer
Obese people are six times as likely to develop gullet (oesophageal) cancer as people of healthy weight, shows research published ahead of print in the journal Gut.
Rates of oesophageal cancer have been rising rapidly, and in some countries, they have risen faster than those of every other major cancer, say the authors.
The findings are based on a comparison of almost 800 people with oesophageal cancer and almost 1600 randomly selected people eligible to vote, who did not have the disease.
Men and those under the age of 50 were particularly vulnerable, the findings showed.
The link between acid reflux and gullet cancer is well known, and unsurprisingly, repeated symptoms of severe heartburn or gastrointestinal reflux disease (GORD) were linked to a much higher risk of the cancer.
And the more frequent the symptoms, the greater was the likelihood of having oesophageal cancer.
GORD quintupled the risk of oesophageal cancer, and a combination of obesity and acid reflux boosted the chances of having it by a factor of 16.
But people who were clinically obese had a much higher risk of oesophageal cancer than those whose weight was in the healthy range, regardless of whether they had reflux disease or not.
Those with a body mass index (BMI) of 40 or more were six times as likely to have the cancer as those with a BMI between 18.5 and 25.........
Posted by: Sue Read more Source