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The widespread use of no-calorie sweeteners may actually make it harder for people to control their intake and body weight, according to researchers at Purdue University’s Ingestive Behavior Research Center. The findings, published in the journal Behavioral Neuroscience, showed that relative to rats that ate yogurt sweetened with glucose, rats given yogurt sweetened with zero-calorie saccharin later consumed more calories, gained more weight, put on more body fat, and didn’t make up for it by cutting back later, all at levels of statistical significance. The authors believe that by breaking the connection between a sweet sensation and high-calorie food, the use of saccharin changes the body’s ability to regulate intake. Problems with self-regulation might explain in part why obesity has risen in parallel with the use of artificial sweeteners. Because people may have different experiences with artificial and natural sweeteners, human studies that don’t take into account prior consumption may produce a variety of outcomes. The researchers noted that their findings match emerging evidence that people who drink more diet drinks are at higher risk for obesity and metabolic syndrome, a collection of medical problems such as abdominal fat, high blood pressure, and insulin resistance that put people at risk for heart disease and diabetes.

 

CARDIOVASCULAR DISEASE: POPULATION STUDY SHOW HEART AILMENTS MAY BE ON THE RISE
A Mayo Clinic analysis of two decades of autopsy results shows a long-term decline in the prevalence of coronary disease has ended and the disease may be on the upswing. The findings, published in the Archives of Internal Medicine, will be the first change in the trend since the decline in heart disease death rates began in the mid-1960s. The analysis over the entire 23-year period revealed declines for three distinct categories: high level, any level, and average degree of coronary artery disease. However, the declines in the degree of disease stopped after 1995 and may have actually headed upward after the year 2000.

 

A cellular protein that helps guide immune cells to the gut has been newly identified as a target of HIV when the virus begins its assault on the body's immune system, according to researchers from the National Institute of Allergy and Infectious Diseases. The researchers said the identification of this new receptor opens up new avenues of investigation that may help scientists understand the complex mechanisms of HIV and could lead to new drugs to fight the virus. In the study, published online in Nature Immunology, scientists identify a cell adhesion molecule known as integrin alpha 4 beta 7 as another potentially important receptor for HIV. Early in the course of HIV infection, the virus rapidly invades and replicates in gut-associated lymphoid tissue (GALT), the immune cells of the gut. Once seeded with HIV, the gut is rapidly depleted of CD4+ T cells, the main target of HIV, triggering the process that ultimately leads to AIDS.

 

OBESITY: HIGHER BODY MASS INDEX MEANS HIGHER RISK OF SEVERAL CANCERS
Increased body mass index increases the risk of common and less common cancers, and the level of risk can vary between the sexes and different ethnic groups depending on the type of cancer, according to researchers at the University of Manchester and Christie Hospital NHS Foundation Trust, Manchester, U.K. The study, published in The Lancet, adds to the growing evidence that excess weight, whether in people who are overweight or obese, is an important risk factor for some common cancers. The researchers found in men, increased BMI raised the risk of esophageal adenocarcinoma and thyroid, colon, and kidney cancers. In women, a BMI increase increased the risk of endometrial, gallbladder, esophageal adenocarcinoma, and kidney cancers. They also noted weaker, but nonetheless significant, positive associations between increased BMI and rectal cancer and malignant melanoma in men; post-menopausal breast, pancreatic, thyroid, and colon cancers in women; and leukemia, multiple myeloma, and non-Hodgkin's lymphoma in both sexes.

 

A study published online in the journal Blood demonstrates for the first time that embryonic stem cells can be used to create functional immune system blood cells. Researchers at the University of Iowa, who led the study, said the finding is an important step in the use of embryonic stem cells as an alternative source of cells for bone marrow transplantation. Embryonic stem cells, or ESCs, are being investigated as a renewable source of primitive cells theoretically able to regenerate all tissues and organs. The use of ESC-derived blood-forming cells may have an important advantage over traditional transplants that use bone marrow, umbilical cord blood, and peripheral blood from donors. The antigens on the surface of donated cells must be compatible (determined by a method called HLA matching) with those of the patient to prevent rejection. The use of embryonic stem cells, which have low levels of these antigens and may therefore be less likely to provoke a defensive reaction by the patient’s body, may allow patients who can’t find suitable HLA-matched donors to receive transplants.

 

Research published in The Journal of Neuroscience indicates that the effects of nicotine and opiates on the brain's reward system are equally strong in a key pleasure-sensing area of the brain—the nucleus accumbens. Researchers at the University of Chicago Medical Center found that while nicotine and opiates are very different drugs, the endpoint, with respect to the control of the neurotransmitter dopamine signaling, is almost identical. Dopamine is released in certain brain areas, including the nucleus accumbens, by naturally rewarding experiences such as food, sex, some drugs, and the neutral stimuli or “cues” that become associated with them. The researchers hope is the study will help identify new methods for treating addiction—and not just for one drug type. They also said it reinforces the fact that these addictions are very physiological in nature and that breaking away from the habit is certainly more than just mind over matter.

 

TERRORISM: SEPTEMBER 11 ATTACKS CONTINUE IMPACT ON MENTAL HEALTH OF AMERICANS
Americans' terrorism-related thoughts and fears are associated with increased depression, anxiety, hostility, post-traumatic stress, and drinking, researchers at the University of Illinois at Chicago report. The researchers examined the extent to which the strength of people's post–September 11 beliefs and fears, as assessed in 2003, predicted a range of psychological distress and alcohol abuse in 2005. Data were derived from a mail survey, which began before September 11 and continued in 2005. The researchers measured the effect of larger, macro-level sociological stressors—rather than personal or micro-level events, such as a death in the family or financial difficulties—on mental health. In the study, published in the Journal of the American Public Health Association, 30 percent of participants reported feeling very or extremely more pessimistic about world peace, and 27.6 percent reported they had less faith in the government's ability to protect them. 

 

In a study to examine the impact of desired body weight on the number of unhealthy days subjects report over one month, researchers at Columbia University Mailman School of Public Health found that the desire to weigh less was a more accurate predictor of physically and mentally unhealthy days than body mass index. In addition, the desire to lose weight was more predictive of unhealthy days among whites than among African-Americans or Hispanics, and among women than among men. The paper, which will be published in the March issue of the American Journal of Public Health, suggest that some of the obesity epidemic may be partially attributable to social constructs that surround ideal body types. The researchers emphasize that there is a large body of evidence suggesting that social stress adversely affects mental health as well as physical health, and said their findings confirmed that there was a positive relationship between a person’s actual weight and his or her desired weight and health, be it physical or mental.

 

Researchers at Yale School of Medicine have developed a blood test with enough sensitivity and specificity to detect early-stage ovarian cancer with 99 percent accuracy. In a study published in the journal Clinical Cancer Research, the researchers said the ability to recognize nearly 100 percent of new tumors will have a major impact on the high death rates of ovarian cancer. Epithelial ovarian cancer is the leading cause of gynecologic cancer deaths in the United States and three times more lethal than breast cancer. It is usually not diagnosed until its advanced stages and has come to be known as the “silent killer.” The test uses six protein biomarkers instead of the four used in a previous version. That has increased the specificity of the test to 99.4 from 95 percent. The test is in a late-stage clinical trial and is available at Yale through the Discovery to Cure program. Yale has licensed the test to three companies: Lab Corp. in the United States, Teva in Israel and SurExam in China.

 

CERVICAL CANCER: STRESS MAY INCREASE A WOMAN’S RISK

A woman’s daily stress can reduce her ability to fight off a common sexually transmitted disease and increase her risk of developing the cancer it can cause, according to researchers from the Fox Chase Cancer Center. No such association is seen, however, between past major life events, such as divorce or job loss, and the body’s response to the infection. Human papillomavirus (HPV) is spread during sexual intercourse. The most common subtype of the virus is HPV16. Infection with HPV16 and other HPV subtypes can cause cervical cancer, but HPV infection alone is not sufficient to cause cervical cancer. Most HPV infections in healthy women will disappear spontaneously over time. Only a small percentage will progress to become precancerous cervical lesions or cancer. An effective immune response against HPV can lead to viral clearance and resolution of HPV infection. However, some women are less able to mount an effective immune response to HPV. The researchers, who published their findings in the Annals of Behavioral Medicine, examined potential associations between stress and immune response to HPV among women who had precancerous cervical lesions. They found no significant association between the occurrence of major stressful life events and immune response to HPV16, but their findings about subjective daily stress told a different story. Women with higher levels of perceived stress were more likely to have an impaired immune response to HPV16. That means women who report feeling more stressed could be at greater risk of developing cervical cancer because their immune system can’t fight off one of the most common viruses that causes it.

 

A study from researchers at Massachusetts General Hospital and the Association of American Medical Colleges finds that many U.S. medical schools do not have policies that govern conflicts of interest related to financial interests the institutions have with public or private companies. In an article in the Journal of the American Medical Association, the researchers report that while about 70 percent of responding medical schools have policies related to the financial interests of key institutional officials, only about than a third have policies addressing the interests held by the institution itself. The study is the first systematic national examination of the adoption and scope of medical schools’ institutional conflict of interest policies. The researchers said the results raise questions about whether the national associations have given enough attention to the mechanics and complexity of implementing these policies.

 

BREAST CANCER: WEBSITES ARE MOSTLY ACCURATE, BUT PATIENTS SHOULD BE SKEPTICAL
An extended analysis by researchers at the University of Texas M. D. Anderson Cancer Center and the University of Texas School of Health Information Sciences in Houston of web pages dedicated to disseminating breast cancer information have determined that one in 20 pages featured inaccuracies. The study also found alternative medicine sites were 15 times more likely to contain false or misleading health information. The study, published online in the journal Cancer, said that while consumers are taught to look for websites where the author's credentials are identified, his or her affiliations are disclosed, and other information is listed, none of this ensures accuracy. The researchers recommend that patients be skeptical and make sure what they read is applicable to their specific medical well-being and not to take action without consulting a clinician.

 

A team of researchers led by the Fred Hutchinson Cancer Research Center has identified a mechanism that explains why some recurrent ovarian tumors become resistant to treatment with commonly used platinum-based chemotherapy drugs such as cisplatin and carboplatin. Their findings, reported in the online edition of the journal Nature, while based on the study of ovarian-cancer cells from women with inherited mutations in the BRCA2 gene, may also help explain the mechanics of cisplatin resistance in ovarian-cancer patients with BRCA1-gene mutations. Together, such genetic mistakes are thought to cause about 10 percent of ovarian cancers. They found that when exposed to cisplatin, some ovarian-cancer cells develop secondary mutations on their BRCA2 gene that restore the gene’s ability to repair DNA. This restoration of gene function then makes the cancer cells resistant to chemotherapy.

 

A young asthmatic woman who collapsed and died shortly after arriving for her shift as a waitress at a bar may be the first death to be reported nationally from acute asthma associated with environmental tobacco smoke, according to a physician at Michigan State University. The report, published in the American Journal of Industrial Medicine, not only outlines circumstances under which the woman died, but also raises a number of issues regarding safety in the workplace. The report states the woman arrived at the bar in Michigan and, according to co-workers, seemed happy and healthy. About 15 or 20 minutes later she collapsed and within a few minutes died. A 2006 report from the surgeon general concluded that environmental tobacco smoke causes coronary heart disease, lung cancer, and premature death. But at that time there was little hard evidence linking it to the exacerbation of asthma in adults. The study’s author said the death dramatizes the need to enact legal protections for workers in the hospitality industry from secondhand smoke. In the United States, 23 states have already banned smoking in restaurants and bars.

SLEEP APNEA: SURGERY IMPROVES QUALITY OF LIFE FOR CHILDREN

For children who suffer from obstructive sleep apnea, a tonsillectomy and adenoidectomy can provide dramatic relief and is successful in solving sleep problems for 80 percent to 90 percent of children, a Saint Louis University study found. The study is the largest to date that looks at how children with varying severities of obstructive sleep apnea fare before and after they have surgery, using both preoperative and postoperative sleep studies. Children who suffer from the disorder stop breathing periodically throughout the night and snore very loudly. In normal weight children, the condition is caused by enlargement of the tonsils and adenoids that aggravates upper airway collapse during sleep, which disrupts normal breathing.  Because they do not sleep soundly, children who suffer from obstructive sleep apnea can experience negative effects on their behavior, health, growth, attention, memory, and classroom performance. OSA has also been linked to lower childhood IQ scores.

 

A new University of Illinois study shows that exercise-trained mice get far fewer gallstones than sedentary mice and identifies potential mechanisms to explain why this occurs. The study, recently published in the Journal of Applied Physiology, provides direct evidence that physical activity reduces gallstone formation. Gallbladder disease affects 10 to 25 percent of adults in the United States, although some persons who are affected may not have symptoms. It has the second highest cost of any digestive disease at $5.8 billion annually and results in over 800,000 hospitalizations each year. Gallstones form when bile cholesterol levels become high enough to precipitate, fall out of solution, and solidify. The scientist found that after 12 weeks, mice in a sedentary group had stones that weighed two and a half times more than the stones in a group of mice that exercised. The researchers found an increase in the expression of two genes (LDLr and SRB1) that help bring cholesterol into the liver to clear it from the circulation. They also found that a protein called Cyp27 was up-regulated about two a half times; this resulted in there being more bile acids to solubilize the increased cholesterol so it didn’t turn into gallstones.