April 16, 2006, 8:13 PM CT

More Research Needed Into Cholesterol Prostate Cancer Link

Cancer Research UK has called for further research after a study claimed to have identified a link between cholesterol intake and prostate cancer risk.

The research, by the Istituto di Ricerche Farmacologiche Mario Negri in Italy and reported in the annals of Oncology, used questionnaires to assess men?s medical histories, including their prior cholesterol levels.

"This study is based on questionnaires rather than directly measured cholesterol levels, so follow-up research is needed before the firm conclusion can be drawn that high cholesterol levels are directly linked to prostate cancer risk," said Henry Scowcroft of Cancer Research UK.

"There is some evidence to suggest that men who eat a high fat diet have a greater risk of prostate cancer, but we do not know for sure whether high levels of fats in the bloodstream actually cause prostate cancer.

"It may be that men who lead a typical western lifestyle are exposed to other factors that could increase their risk," he added.

Some prior research has suggested a link between prostate cancer and cholesterol levels, but firm evidence has remained elusive.

Prostate cancer is the most common form of the disease among men in the UK, with 30,100 new cases diagnosed every year.........

Posted by: Mark      Permalink         Source

April 15, 2006, 3:33 PM CT

Bringing New Life To Kidney Treatment

Finding how two proteins conspire to get kidney cells to self-destruct when oxygen supplies are low may one day improve dismal mortality rates for ischemic renal failure, scientists say.

Dehydration, low blood pressure, septic shock, trauma or removing a kidney for transplantation can temporarily halt or reduce blood and oxygen supplies, says Dr. Zheng Dong, cell biologist at the Medical College of Georgia.

Ischemia leads to cell suicide or apoptosis, especially in the energy-consuming tubular cells of the kidneys, he says. Fifty percent mortality rates from resulting ischemic renal failure haven't changed in nearly as a number of years, Dr. Dong says.

Tubular cells - which have the daunting daily task of reabsorbing nearly 50 gallons of usuable fluid volume, including salt and glucose the kidneys filter from the blood every 24 hours - are especially vulnerable to apoptosis and injury, Dr. Dong says.

"They are highly energy-dependent," he says. "That is why when you shut off the blood supply, these cells are quickly, irreversibly damaged and they die." Tubular cell injury and death is why kidneys are so vulnerable, for example in critically ill patients.

It's in this oxygen-deprived environment that two proteins, Bid and Bax - each a known killer in its own right - are activated and may partner to induce cell death. The killing proteins are pervasive, especially in the kidneys, says Dr. Dong, who recently received a $1 million grant from the National Institute of Diabetes & Digestive & Kidney Diseases, to better understand their role in cell death during ischemic renal failure.........

Posted by: Mark      Permalink         Source

April 15, 2006, 2:30 PM CT

Gene Decreases Retinal Degeneration In Fruit Flies

Johns Hopkins scientists have discovered a gene in fruit flies that helps certain specialized neurons respond more quickly to bright light. The study, reported in the April 4 issue of Current Biology, also has implications for understanding sensory perception in mammals.

In teasing apart the molecular interactions and physiology underlying light perception, the scientists studied a gene they dubbed "Lazaro" that is expressed 15 times higher in the fly eye than the rest of the fly head. They found that this gene is mandatory for a second biochemical pathway that controls the activity of a protein called the TRP channel. TRP channels are found in fruit fly neurons responsible for sensing light. The fly TRP channel is the founding member of a family of related proteins in mammals that are essential for guiding certain nerves during development and for responding to stimuli including heat, taste and sound.

By shining bright light onto and recording electrical changes in single nerve cells in the fly eye, scientists found that neurons carrying a mutation in this gene cannot respond as well to light as compared to neurons carrying normal copies of this gene. In fact, the mutant neurons turn off their response to light four times faster than normal neurons. Because Lazaro helps fly TRP channels work at their maximum, it is possible that a Lazaro-like gene in mammals might also play a role in how well mammalian TRP channels work.........

Posted by: Mike      Permalink         Source

April 15, 2006, 1:53 PM CT

How Others Influence Our Behavior

An article reported in the latest issue of Current Directions in Psychological Science finds that we are tied to each other-- what other people do and how they express their feelings is a contagious, strong influence. Stirring in the background of our minds are the influences of other people that affect us without our knowledge or recognition.

For example when scientists showed individuals a picture of a library and instructed them to go there after the experiment, participants began to speak more softly, without being aware of why. Similarly, when primed to be rude, individuals interrupted a speaker, while those primed to be polite did not.

The article argues that we should not assume we are aware of most of the important influences on our behavior and judgments, and to accept that there are influences we do not know about. Only then would one have a chance at counteracting those influences and regaining control. At the same time, however, we can be reassured by the knowledge that these automatic influences over us are typically benign, and help keep us in touch with our present circumstances while our conscious mind is time-traveling into the past (memory) or the future (planning).........

Posted by: JoAnn      Permalink         Source

April 14, 2006, 11:25 AM CT

Two Tests Better Than One

In a strongly worded review reported in the recent edition of The Journal of the American Medical Association (JAMA), the head of the Johns Hopkins Diabetes Center urges physicians and patients to better use the blood-testing tools at hand to manage the disease and prevent most of its dire impact on the heart, kidneys, nerves and vision.

"The message is, we have tools that are very accurate, but they don't work at all if they are not used properly," says Christopher Saudek, M.D., a former president of the American Diabetes Association and lead author of the article. "If the goal of therapy is to prevent morbidity and mortality, we need to do a better job of monitoring our patients, as well as advising them."

Saudek and his colleagues reviewed data from studies conducted between 1976 and 2005 and concluded that both self-monitoring of blood glucose (SMBG) and more precise doctor testing of hemoglobin A1c (HbA1c) can help diabetics take proper control of their blood sugar levels and successfully manage their disease.

"Used together, self monitoring and A1c do work," says Saudek, along with "consistent communication between the patient and health care professional."

As per the ADA, an estimated 14.6 million people in the United States have been given a diagnosis of diabetes, most of them with so-called type 2 or adult onset. Their disease is marked by the body's inability to respond to insulin to break down glucose, or sugar.........

Posted by: JoAnn      Permalink         Source

April 14, 2006, 11:19 AM CT

Older Donor Hearts Just As Good

Patients who receive healthy hearts from donors 50 years of age and older appear to fare just as well as patients who receive younger hearts, and that may be good news for potentially expanding a small donor pool, a University of Alberta study has observed.

A study reported in the March/April 2006 issue Journal of Cardiac Surgery reviewed the outcomes of using heart donors 50 years of age and older and discovered that there were no differences in ICU or post-operative length of hospital stay, days ventilated, or early rejection episodes.

The scientists analyzed 338 cardiac adult transplants performed at the University of Alberta Hospital between 1988 and 2002. Of those, 284 patients received hearts from donors under 50 and 54 received hearts aged 50 and older.

Recipients of the older hearts had a greater risk of death within 30 days of surgery, and pretransplant diabetes also played a significant role in survival, but despite that, long-term outcomes were similar to those of younger donor hearts. Both sets of patients had similar survival rates--at the end of 10 years, the survival rate for older hearts was 58 per cent versus 59 per cent for patients with younger donor hearts.

The research is good news for patients who will need heart transplants, said one of the study's co-authors, Dr. Shaohua Wang of the University of Alberta's Division of Cardiac Surgery. "As the population ages, it can be expected that the number of patients requiring transplantations will also increase."........

Posted by: Daniel      Permalink         Source

April 14, 2006, 9:34 AM CT

Taller people more likely to develop atrial fibrillation

Analysis of data from a registry of patients with left ventricular dysfunction indicates that height is an independent risk factor for an arrhythmia of the upper chambers of the heart, as per a new study in the April 18, 2006, issue of the Journal of the American College of Cardiology.

"Tall stature is a potent risk for the development of atrial fibrillation and is independent of other clinical risk factors. Indeed, the male predominance of atrial fibrillation appears to be explained by the difference in height between men and women," said Jonathan J. Langberg, M.D. from Emory University in Atlanta, Georgia.

Atrial fibrillation is the most common sustained cardiac arrhythmia. During an episode, the upper chambers of the heart flutter instead of pumping blood effectively. The incidence increases as people age, with a prevalence of more than 5 percent in patients over the age of 65 years.

The size of the left atrium of the heart is known to be associated with atrial fibrillation, so the scientists wanted to see if bigger people have a higher risk of atrial fibrillation.

"It is well known that small animals do not develop atrial fibrillation, while those larger than humans, especially horses, seem to be quite susceptible. I also encountered a string of very tall patients, most of whom were former basketball players, with lone atrial fibrillation," Dr. Langberg said.........

Posted by: Daniel      Permalink         Source

April 14, 2006, 9:30 AM CT

Placental Growth Factor For Repair Heart Attack Damage

Heart attack patients produce higher levels of a natural substance in the body that plays a role in the growth of new blood vessels and this over-expression of placental growth factor (PlGF) may help reduce damage to the heart muscle, as per a new study in the April 18, 2006, issue of the Journal of the American College of Cardiology.

"Because the degree of PlGF production released from the heart after a heart attack correlated with the improvement of cardiac function, we think PlGF becomes a potential therapy of myocardial infarction. Furthermore, prior studies have shown that PlGF enhances angiogenesis and arteriogenesis in ischemic tissue, also PlGF appears to promote mobilization of flt-1-positive hematopoietic stem cells from bone marrow to the peripheral circulation. We have started further experiments to evaluate this hypothesis," said Shiro Uemura, M.D. from the Nara Medical University in Kashihara, Japan.

The researchers, including first author Hajime Iwama, M.D., compared 55 heart attack patients to 43 control subjects. The heart attack patients had significantly higher levels of PlGF than the healthy subjects. Also, the patients with higher levels of PlGF three days after a heart attack had lower left ventricular ejection fractions, indicating more heart muscle damage. The scientists wrote that it is likely that the degree of injury is a key determinant of how much PlGF the body produces.........

Posted by: Daniel      Permalink         Source

April 14, 2006, 9:19 AM CT

Sleep Problems And Heart

Patients with severe sleep-disordered breathing are two to four times more likely to experience complex, abnormal heart rhythms while sleeping than individuals without the problem, as per the Sleep Heart Health Study (SHHS).

These findings are reported in the April 15 issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Reena Mehra, M.D., M.S., of University Hospitals of Cleveland at Case Western Reserve University in Ohio, and seven associates compared the prevalence of arrhythmias in 228 patients with sleep-disordered breathing and 338 with no sleep disorder. The individuals in both groups participated in the SHHS, a multi-center longitudinal study of designed to determine the cardiovascular consequences of sleep-disordered breathing (SDB).

SDB is an illness in which a sleeping individual repeatedly stops breathing for 10 seconds or longer before resuming air intake. These stoppages decrease the amount of oxygen and increase the level of carbon dioxide in the blood and brain. In this study, participants with SDB had a respiratory disturbance index that averaged about 44 pauses per hour of sleep. The control subjects experienced only 2.8 interruptions per hour.

"Individuals with sleep-disordered breathing had four times the odds of atrial fibrillation and three times the odds of nonsustained ventricular tachycardia," said Dr. Mehra.........

Posted by: Scott      Permalink         Source

April 14, 2006, 9:14 AM CT

Breathing Gas Mixture May Improve COPD

Breathing a special gas mixture may significantly improve the exercise performance of individuals with severe chronic obstructive pulmonary disease (COPD). During an endurance walking test, the patients found that they could improve their walking distance by 64 percent with less shortness of breath.

The results appear in the April 15th issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.

Elizabeth A. Laude, Ph.D., of the University of Sheffield in the United Kingdom, and seven associates investigated the effects of varying oxygen and helium levels in the air breathed during exercise by 82 patients who had severe, but stable COPD.

The researchers tested four different gas mixtures with the patients: 72 percent helium and 28 percent oxygen (Heliox28); 79 percent helium and 21 percent oxygen (Heliox21); 72 percent nitrogen and 28 percent oxygen (Oxygen28); and 79 percent nitrogen and 21 percent oxygen (medical air).

"Patients walked significantly further while breathing Heliox 28 than with either Heliox 21 or Oxygen 28," said Dr. Laude.

By replacing the nitrogen with normal supplementary oxygen with lower density helium gas, the scientists hoped that they might reduce airway resistance and improve the participants' respiratory gas exchange.........

Posted by: Scott      Permalink         Source