August 2, 2010, 6:40 AM CT

Both Short and Long Sleep Durations are Risk Factors

A study in the Aug. 1 issue of the journal SLEEP suggests that regularly sleeping for more or less than seven hours per day is linked to an increased risk of cardiovascular disease.

Results show that eight percent of the study population reported sleeping five hours per day or less including naps, and multivariable logistic regression analysis revealed that their risk of any cardiovascular disease was more than two times higher than that of people who reported a daily sleep duration of seven hours (adjusted odds ratio = 2.20). Nine percent of participants reported sleeping nine hours or more per day, and they also had an elevated risk of cardiovascular disease (adjusted OR = 1.57). Results were adjusted for potential confounders such as age, sex, race, smoking, alcohol consumption, body mass index, physical activity, diabetes, high blood pressure and depression.

"Our study findings suggest that abnormal sleep duration adversely affects cardiovascular health," said principal investigator Anoop Shankar, MD, PhD, Associate Professor in the Department of Community Medicine at West Virginia University School of Medicine in Morgantown, W.V. "Sleep disturbances appears to be a risk factor for cardiovascular disease even among apparently healthy subjects".

Shankar and main author Charumathi Sabanayagam, MD, analyzed data from 30,397 adults who participated in the 2005 National Health Interview Survey, which collected information on demographic factors, socioeconomic characteristics, lifestyle and health. Sleep duration was assessed by the question, "On average, how a number of hours of sleep do you get in a 24-hour period?" Participants reported 2,146 cases of cardiovascular disease, which was defined as a doctor diagnosis of angina, coronary heart disease, heart attack or stroke......... Posted by: Daniel      Read more         Source

August 2, 2010, 6:36 AM CT

How stem cells determine what tissue to become

Within 24 hours of culturing adult human stem cells on a new type of matrix, University of Michigan scientists were able to make predictions about how the cells would differentiate, or what type of tissue they would become. Their results are reported in the Aug. 1 edition of Nature Methods

Differentiation is the process of stem cells morphing into other types of cells. Understanding it is key to developing future stem cell-based regenerative therapies.

"We show, for the first time, that we can predict stem cell differentiation as early as Day 1," said Jianping Fu, an assistant professor in mechanical engineering and biomedical engineering who is the first author on the paper.

"Normally, it takes weeks or maybe longer to know how the stem cell will differentiate. Our work could speed up this lengthy process and could have important applications in drug screening and regenerative medicine. Our method could provide early indications of how the stem cells are differentiating and what the cell types they are becoming under a new drug therapy".

In this study, Fu and colleagues examined stem cell mechanics, the slight forces the cells exert on the materials they are attached to. These traction forces were suspected to be involved in differentiation, but they have not been as widely studied as the chemical triggers. In this paper, the scientists show that the stiffness of the material on which stem cells are cultivated in a lab does, in fact, help to determine what type of cells they turn into......... Posted by: Scott      Read more         Source

August 2, 2010, 6:33 AM CT

Meat components may cause bladder cancer

A newly released study suggests that consuming specific compounds in meat correlation to processing methods appears to be linked to an increased risk of developing bladder cancer. Published early online in CANCER, a peer-evaluated journal of the American Cancer Society, the findings appears to be relevant for understanding the role of dietary exposures in cancer risk.

Eating red and processed meats has been associated with an increased risk of developing several different types of cancer. Animal studies have identified many compounds in meat that might account for this association. These include heterocyclic amines, polycyclic aromatic hydrocarbons, and N-nitroso compounds. Nitrate and nitrite are added to processed meats and are known precursors to N-nitroso compounds.

Amanda J. Cross, PhD, of the National Cancer Institute in Rockville and his colleagues conducted one of the first prospective studies the NIH-AARP Diet and Health Studyto assess the relationship between intake of these meat-related compounds and the risk of developing bladder cancer. They used information gathered through questionnaires to assess the types of meat consumed as well as how meat was prepared and cooked to estimate the intake of these meat-related compounds.

The researchers had information from approximately 300,000 men and women aged 50 to 71 years from eight US states. At the start of the study (1995 to 1996), all participants completed lifestyle and dietary questionnaires about their usual consumption of foods and drinks. The participants were followed for up to eight years, during which time 854 people were diagnosed with bladder cancer......... Posted by: Janet      Read more         Source

August 2, 2010, 6:30 AM CT

How cancer-causing bacterium works?

Scientists have discovered a mechanism by which Helicobacter pylori, the only known cancer-causing bacterium, disables a tumor suppressor protein in host cells.

The newly released study, in the journal Oncogene, reports the discovery of a previously unknown mechanism linking H. pylori infection and stomach cancer, the second leading cause of cancer deaths worldwide.

About two-thirds of the world's population is infected with H. pylori, a bacterium that can survive in the harsh environment of the stomach. Most infected people never develop disease. For a significant minority, however, infection with H. pylori leads to inflammation, ulcers and in some cases, stomach (gastric) cancer.

H. pylori's ability to cause disease is closely linked to a virulence protein called CagA. Prior studies have observed that CagA-positive strains are much more likely to cause inflammation and spur the abnormal cell division and growth of cells that lead to cancer.

H. pylori injects CagA into the epithelial cells that line the stomach. Within the cells, CagA is able to hijack various signaling pathways and disrupt proper cellular functions.

Other studies have identified RUNX3 (pronounced RUNKS-three) as an important gastric cancer tumor suppressor......... Posted by: Janet      Read more         Source

July 23, 2010, 7:06 AM CT

African ancestry linked to high-risk breast cancer

A newly released study finds that African ancestry is associated with triple-negative breast cancer, a more aggressive type of cancer that has fewer therapy options.

Scientists at the University of Michigan Comprehensive Cancer Center observed that, among women with breast cancer, 82 percent of African women were triple negative, 26 percent of African-Americans were and 16 percent of white Americans were.

Triple negative breast cancer is negative for three specific markers that are used to determine therapy: the estrogen receptor, the progesterone receptor and HER-2/neu.

"The most significant recent advances in breast cancer therapy have involved targeting these three receptors. But these therapys do not help women with triple-negative breast cancer. Outcome disparities are therefore likely to increase, because fewer African-American women are candidates for these newer therapys," says study author Lisa A. Newman, M.D., M.P.H., director of the Breast Care Center at the U-M Comprehensive Cancer Center.

The study, published online in the journal Cancer, looked at 581 African American women and 1,008 white women diagnosed with breast cancer at the Henry Ford Health System in Detroit, plus 75 African women diagnosed at the Komfo Anokye Teaching Hospital in Ghana......... Posted by: Janet      Read more         Source

July 23, 2010, 7:03 AM CT

Abnormal cells in blood and lung cancer

A novel approach detects genetically abnormal cells in the blood of non-small cell patients with lung cancer that match abnormalities found in tumor cells and increase in number with the severity of the disease, a research team led by researchers at The University of Texas MD Anderson Cancer Center report in the journal Clinical Cancer Research

Patients with lung cancer in the study also had a number of times the number of these circulating abnormal cells than study volunteers in a closely matched control group.

"We suspect additional research will show that these circulating abnormal cells are circulating non-small cell lung cancer cells," said study corresponding author Ruth Katz, M.D., professor in MD Anderson's Department of Pathology. "Blood tests for these circulating tumor cells could be used to diagnose lung cancer earlier, monitor response to treatment and detect residual disease in patients after therapy".

Katz and his colleagues conducted what they believe to be the first study to use a technique called fluorescence in situ hybridization (FISH) to detect abnormal circulating cells that have aberrations found in non-small cell lung cancer. FISH detects and quantifies abnormal cells by using dye-labeled DNA probes of cell chromosomes that cause cells with the targeted genetic abnormalities to light up when viewed under a fluorescent microscope......... Posted by: Scott      Read more         Source

July 23, 2010, 6:59 AM CT

Sugar substitutes help reduce caloric intake

A newly released study reported in the August 2010 journal, Appetite, further demonstrates that people who consume low-calorie sweeteners are able to significantly reduce their caloric intake and do not overeat.

In fact, study participants who received the sugar substitutes instead of sugar consumed significantly fewer calories and there was no difference in hunger levels despite having fewer calories overall.

The scientists noted, "In conclusion, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety when they consumed lower calorie preloads [pre-meals] containing stevia or aspartame than when they consumed higher calorie preloads containing sucrose".

This study was conducted in both healthy and overweight adults and participants were given a pre-meal containing either sucrose, aspartame or stevia. Those who received the stevia or aspartame consumed fewer calories overall, did not overeat and did not report increased feelings of hunger.

"Eventhough the totality of the scientific evidence demonstrates that low-calorie sweeteners and the products that contain them are not correlation to weight gain, increased hunger or overeating, there have been recent reports questioning the benefits of low-calorie sweeteners," notes Beth Hubrich, a dietitian with the Calorie Control Council, an international trade association. "When used as part of an overall healthy diet, low-calorie sweeteners and light products can be beneficial tools in helping people control caloric intake and weight"......... Posted by: JoAnn      Read more         Source

July 22, 2010, 7:42 AM CT

Summer reading keeps skills strong

To children, the summer slide means water, garden hoses and slippery plastic sheets. To teachers, the "summer slide" is the noted decrease in reading skills after a vacation without books.

University of Tennessee, Knoxville, faculty members Richard Allington and Anne McGill-Franzen have completed a three-year study showing a significantly higher level of reading achievement in students who received books for summer reading at home. Allington and McGill-Franzen are both professors of education; McGill-Franzen is also director of the Reading Center in the College of Education, Health and Human Sciences.

Allington compares the slide in reading ability to an athlete's fitness.

"Just like hockey players lose some of their skills if they stay off their skates and off the ice for three months, children who do not read in the summer lose two to three months of reading development," Allington said.

As per the professors' research, the summer reading setback is the primary reason for the reading achievement gap between children who have access to reading materials at home and those who do not. Students who do not have books at home miss out on opportunities to read. Those missed opportunities can really add up.

"What we know is that children who do not read in the summer lose two to three months of reading development while kids who do read tend to gain a month of reading proficiency," Allington said. "This creates a three to four month gap every year. Every two or three years the kids who don't read in the summer fall a year behind the kids who do." ......... Posted by: Janet      Read more         Source

July 22, 2010, 7:39 AM CT

Chili pepper ingredient fights fat

Capsaicin, the stuff that gives chili peppers their kick, may cause weight loss and fight fat buildup by triggering certain beneficial protein changes in the body, as per a newly released study on the topic. The report, which could lead to new therapys for obesity, appears in ACS' monthly Journal of Proteome Research

Jong Won Yun and his colleagues point out that obesity is a major public health threat worldwide, associated with diabetes, high blood pressure, heart disease, and other health problems. Laboratory studies have hinted that capsaicin may help fight obesity by decreasing calorie intake, shrinking fat tissue, and lowering fat levels in the blood. Nobody, however, knows exactly how capsaicin might trigger such beneficial effects.

In an effort to find out, the researchers fed high-fat diets with or without capsaicin to lab rats used to study obesity. The capsaicin-treated rats lost 8 percent of their body weight and showed changes in levels of at least 20 key proteins found in fat. The altered proteins work to break down fats. "These changes provide valuable new molecular insights into the mechanism of the antiobesity effects of capsaicin," the researchers say......... Posted by: JoAnn      Read more         Source

July 22, 2010, 7:36 AM CT

How safe and effective are herbal dietary supplements?

Millions of people are taking herbs and other plant-based dietary supplements to improve their health, but they have precious little information on the actual effectiveness or potential ill effects of these products. That's the topic of an article in the current issue of Chemical & Engineering News (C&EN), ACS' weekly newsmagazine.

C&EN Senior Editor Celia Henry Arnaud suggests that consumers are taking a gamble when it comes to the safety and effectiveness of hundreds of pills and potions cluttering store shelves. Such products include black cohosh and red clover, used by menopausal women to reduce hot flashes, and kava, which is used to treat anxiety and insomnia. Researchers are concerned that some supplements may contain high levels of toxic metals, such as lead and mercury, or pesticides. There's also the possibility that the plant itself might be toxic or that a supplement can cause harm by reacting with conventional drugs.

The U.S. Food & Drug Administration, which regulates supplements as foods rather than drugs, recently took a step toward improving the situation by requiring all supplement manufacturers to test their products for contaminants. But researchers still know little about the ingredients in a number of supplements and what effect they might have on the body. Ongoing research is providing new information that will help address these concerns in the future, including the long-term safety of these products for consumers, the article indicates......... Posted by: Janet      Read more         Source