Class of Diabetes Drugs Carries Significant Cardiovascular Risks
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A class of oral drugs used to treat type 2 diabetes may make heart failure worse, according to an editorial published online in Heart Wednesday by two Wake Forest University School of Medicine faculty members.
“We strongly recommend restrictions in the use of thiazolidinediones (the class of drugs) and question the rationale for leaving rosiglitazone on the market,” write Sonal Singh, M.D., M.P.H., assistant professor of internal medicine, and Curt D. Furberg, M.D., Ph.D., professor of public health sciences. Rosiglitazone and pioglitazone are the two major thiazolidinediones.
In the editorial Singh and Furberg say, “At this time, justification for use of thiazolidinediones is very weak to non-existent.”
Scientists’ Findings May Lead to New Drug-abuse Treatments
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Increased connections among brain cells caused by excessive drug use may represent the body’s defense mechanism to combat addiction and related behaviors, scientists at UT Southwestern Medical Center have found.
Previous studies have shown that repeated use of drugs such as cocaine, amphetamines and nicotine increase the number of anatomical structures called dendritic spines in brain regions associated with pleasure and reward. These dendritic spines represent sites where brain cells communicate with one another. Many scientists believe that this long-lasting brain rewiring underlies the similarly persistent behaviors of drug-taking and drug-seeking associated with addiction and relapse. The mechanism that controls this brain rewiring, however, and its relationship to addiction-related behaviors were previously unknown.
In a study appearing in the Aug. 28 issue of Neuron, researchers found that cocaine suppresses the activity of the protein MEF2 in mice. Because MEF2 normally reduces the number of brain connections, suppressing MEF2 leads to an increase in dendritic spine density. The researchers also found that when they enhanced MEF2 activity in the brain this blocked the drug-induced increase in dendritic spine density and increased addiction-related behavioral responses to cocaine.
New role for Natural Killers!
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Scientists at the University of York have discovered a new role for a population of white blood cells, which may lead to improved treatments for chronic infections and cancer.
Natural Killer (or NK) cells are abundant white blood cells that were recognised over 30 years ago as being able to kill cancer cells in the test tube. Since that time, a role for NK cells in activating other white blood cells (including ‘T’ lymphocytes and phagocytes) and in directing how the immune system responds to a wide range of infections has also been established.
Because of these properties, NK have been widely regarded as being of benefit in the fight against cancer and infection, and methods to increase NK cell activity underpin a range of new experimental anti-cancer drugs and anti-infectives.
Heart attack patients who stop statin risk death, say McGill researchers
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Patients discontinuing statin medication following an acute myocardial infarction (AMI) increase their risk of dying over the next year, say researchers at McGill University and the McGill University Health Centre (MUHC). Their study was published in a recent issue of the European Heart Journal.
Using data on British patients who survived an AMI and were still alive three months later, Dr. Stella Daskalopoulou and colleagues found that those who discontinued their statin medication were 88% more likely to die during the following year compared to those who had never been on the medication.
“Statins were found to be beneficial drugs,” said Dr. Daskalopoulou, of McGill’s Faculty of Medicine and the Department of Medicine and the Division of Clinical Epidemiology at the MUHC. “Patients who used statins before an AMI and continued to take them after were 16% less likely to die over the next year than those who never used them. So even if it appears that the statins failed to prevent your AMI, it is beneficial to continue taking them and potentially quite harmful to stop.”
Health risk behaviors associated with lower prostate specific antigen awareness
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According to a study conducted at Columbia University Mailman School of Public Health, health risk behaviors such as smoking and obesity are associated with lower awareness of the Prostate Specific Antigen (PSA), which could lead to a lower likelihood of undergoing actual prostate cancer screening. Although previous studies have explored predictors of PSA test awareness, this is the first research to focus on health risk behaviors, such as smoking, physical inactivity, obesity, and excessive alcohol consumption. The study findings were reported in the August issue of The Journal of Urology.
Awareness of PSA testing is considered an important cognitive precursor of prostate cancer screening and it was found to contribute to differences in prostate cancer screening rates. Earlier studies have suggested that persons who seek out cancer information are more likely to acquire knowledge, demonstrate healthy behaviors, and undergo cancer screening. According to the Mailman School study, a quarter of the men older than 50 years without a history of prostate cancer who were among the population of 7,000 men studied, remain unaware of the PSA test.
“Our primary findings suggested that smoking, physical inactivity and obesity are inversely associated with awareness of the PSA test. These risk behaviors are linked with higher prostate cancer morbidity and mortality,” said Firas S. Ahmed, MD, MPH, Mailman School of Public Health, and first author. This finding may be due to a general lack of concern about health maintenance or less interactions with health care providers by smokers, according to Dr. Ahmed.
History of nonmelanoma skin cancer is associated with increased risk for subsequent malignancies
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Individuals with a history of nonmelanoma skin cancer (NMSC) are at increased risk for other cancers, according to a study published in the August 26 online issue of the Journal of the National Cancer Institute.
Previous studies have documented that people who have had nonmelanoma skin cancer were at increased risk for developing melanoma, but it is less well-established whether they were also at risk for cancers that do not involve the skin.
In the current study, Anthony Alberg, Ph.D., of the Medical University of South Carolina and colleagues analyzed data from a prospective cohort study called CLUE II, which was established in Washington County, Md., in 1989. Alberg’s team compared the risk of malignancies in 769 individuals who had been diagnosed with nonmelanoma skin cancer and 18,405 individuals with no history of the disease during a 16-year follow-up period.
Chronic stress alters our genetic immune response
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Most people would agree that stress increases your risk for illness and this is particularly true for severe long-term stresses, such as caring for a family member with a chronic medical illness. However, we still have a relatively limited understanding of exactly how stress contributes to the risk for illness. In the August 15th issue of Biological Psychiatry, researchers shed new light on one link between stress and illness by describing a mechanism through which stress alters immune function.
In a very promising preliminary study, Miller and colleagues found that the pattern of gene expression differed between caregivers of family members with cancer relative to a matched group of individuals who did not have this type of life stress. They found that among the caregivers, even though they had normal cortisol levels in their blood, the pattern of gene expression in the monocytes, a type of white blood cell involved in the body’s immune response, was altered so that they were relatively less responsive to the anti-inflammatory actions of cortisol, but relatively more responsive to pro-inflammatory actions of a transcription factor called nuclear factor-kappa B, or NF-κB. Gregory Miller, Ph.D., corresponding author, explains more simply that, although “caregivers have similar cortisol levels as controls, their cells seem to be ‘hearing’ less of this signal. In other words, something goes awry in caregivers’ white blood cells so they are not able to ‘receive’ the signal from cortisol that tells them to shut down inflammation.”
Thus, the current findings might help to explain why the caregivers would seem to be in a chronic pro-inflammatory state, a condition of immunologic activation. This activated state could contribute to the risk for a number of medical illnesses, such as depression, heart disease, and diabetes. Dr. Miller remarks that part of the importance of these findings is “because people have traditionally thought that higher cortisol is the reason that stress contributes to disease, but this work shows that, at least in caregivers, it’s actually the opposite - there’s too little cortisol signal being heard by the cells, rather than too much.”
CSHL scientists identify new drug target against virulent type of breast cancer
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Tumor cells in a particular subset of breast cancer patients churn out too much of a protein called ErbB2—also often called HER2—which drives the cells to proliferate unchecked. Patients unlucky enough to be in this group—about one in four—have poorer prognoses and clinical outcomes than those who don’t.
The drugs Herceptin and Lapatinib, prescribed in combination with other chemotherapeutic agents, have improved this picture significantly, but leave plenty of room for improvement: they suppress ErbB2 but are effective against less than half of ErbB2-producing tumors. Moreover, patients with tumors that do respond usually develop resistance to these drugs.
A team of scientists at Cold Spring Harbor Laboratory has just published research identifying an enzyme called Brk that may serve as a target for future drugs developed to fight ErbB2-positive tumors. Brk, they report, helps these tumors become virulent and is also implicated in the process through which the tumors develop drug resistance.
California tobacco control program saved billions in medical costs
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California’s state tobacco control program saved $86 billion—in 2004 dollars—in personal healthcare costs in its first 15 years, according to a study by researchers at the University of California, San Francisco.
During the same period, the state spent only a total of $1.8 billion on the program, a 50-to-1 return on investment, according to study findings. The study is the first that has been able to quantifiably connect tobacco control to healthcare savings, say its authors.
The healthcare savings occurred because the program prevented 3.6 billion packs of cigarettes—worth $9.2 billion to the tobacco industry—from being smoked between 1989, when the state-funded California Tobacco Control Program began, and 2004, when this study ended.
Potential diabetes treatment selectively kills autoimmune cells from human patients
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In experiments using blood cells from human patients with diabetes and other autoimmune disorders, Massachusetts General Hospital (MGH) researchers have confirmed the mechanism behind a potential new therapy for type 1 diabetes. A team led by Denise Faustman, MD, PhD, director of the MGH Immunobiology Laboratory, showed that blocking a metabolic pathway regulating the immune system specifically eliminated immune cells that react against a patient’s own tissues.
Faustman and her colleagues previously discovered a technique that reversed type 1 disease in a mouse model. The current study, which will appear in the Proceedings of the National Academy of Sciences and has been released online, is the first demonstration of this strategy in human cells and supports the viability of a clinical trial that is currently underway.
“Our studies in mice showed that we could selectively kill the defective autoimmune cells that were destroying insulin-producing islets,” says Faustman. “These results show that the same selective destruction can occur in humans cells and connect what we saw in our animal studies with the protocol we are pursuing in our Phase I clinical trial.”
Infections linked to premature births more common than thought, Stanford study finds
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Previously unrecognized and unidentified infections of amniotic fluid may be a significant cause of premature birth, according to researchers at the Stanford University School of Medicine.
An analysis of amniotic fluid from women in preterm labor indicated that 15 percent of the fluid samples harbored bacteria or fungi - an increase of 50 percent over previous estimates. The heavier the burden of infection, the more likely the women were to deliver younger, sicker infants.
“If we could prevent these infections in the first place, or detect them sooner, we might one day be able to prevent some of these premature births,” said research associate Dan DiGiulio, MD, who conducted the study in the laboratory of senior author David Relman, MD. About 12 percent of all births in this country are premature and the frequency of premature birth is increasing.
Low cholesterol associated with cancer in diabetics
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Low levels of LDL cholesterol as well as high levels are associated with cancer in patients with type 2 diabetes, found a prospective cohort study http://www.cmaj.ca/press/pg427.pdf published in CMAJ.
Researchers from the Hong Kong Institute of Diabetes and Obesity, the Li Ka Shing Institute of Health Sciences and The Chinese University of Hong Kong conducted a study of 6107 Chinese patients with type 2 diabetes and found a V-shaped risk relation between LDL cholesterol and cancer in patients not receiving statin therapy.
“LDL cholesterol levels below 2.80 mmol/L and levels of at least 3.90 mmol/L were both associated with markedly elevated risk of cancer among patients who did not use statins,” state Dr. Juliana Chan and coauthors.
Women exposed to negative life events at greater risk of breast cancer: BGU study
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Happiness and optimism may play a role against breast cancer while adverse life events can increase the risk of developing the disease, according to a study by Professor Ronit Peled, at Ben-Gurion University of the Negev in Israel. An article on the study titled “Breast Cancer, Psychological Distress and Life Events among Young Women,” was just published in the British journal BMC Cancer (8:245, August 2008).
In the study, researchers questioned women about their life experiences and evaluated their levels of happiness, optimism, anxiety, and depression prior to diagnosis. Researchers used this information to examine the relationship between life events, psychological distress and breast cancer among young women.
A total of 622 women between the ages of 25 and 45 were interviewed: 255 breast cancer patients and 367 healthy women. “The results showed a clear link between outlook and risk of breast cancer, with optimists 25 percent less likely to have developed the disease. Conversely, women who suffered two or more traumatic events had a 62 percent greater risk,” Peled said. “Young women who have been exposed to a number of negative life events should be considered an ‘at-risk’ group for breast cancer and should be treated accordingly.”
Asthma monitoring on the Web
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An inexpensive web-enabled device for measuring lung function in patients with asthma and other disorders is being developed by researchers at Texas Instruments, in Bangalore, India, and co-workers. Writing in the International Journal of Biomedical Engineering and Technology, the team explains how the devise could allow physicians to monitor their patients remotely and quickly instigate medical attention in an emergency.
Spirometers are commonly used to measure lung capacity and the response of breathing during therapy. However, the widespread application of spirometers is limited in the developing world and in remote regions because of the high instrument cost of the instrument and a lack of specialist healthcare workers trained in its use.
Texas Instruments researcher N.C.S. Ramachandran is an expert in high-speed and low-power digital design and is working with professor of electrical engineering Vivek Agarwal of the Indian Institute of Technology, Bombay, India, on the development of an inexpensive and easy to operate spirometer that can be quickly hooked up to an internet connection through built-in web and data encryption software.
“Good” fat may be new weapon in obesity fight
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A new understanding of the origins of brown fat cells—the “good” kind of fat that burns energy and keeps us warm—may lead to new treatments for obesity, two research teams reported on Wednesday.
Researchers at the Dana-Farber Cancer Institute in Boston said they used a single molecular switch to turn immature muscle cells into brown fat cells in the lab, suggesting that brown fat may be more akin to muscle cells than conventional white fat cells.
A second team from the Joslin Diabetes Center in Boston, found a protein important for bone growth helped promote the development of brown fat tissue in mice.
