Meds

December 27, 2009

Social Isolation Adversely Affects Breast Cancer

Filed under: Uncategorized — admin @ 10:16 am

A socially isolated, stressful environment can speed up the growth of breast cancer, researchers studying the effects of stress in animal models reported Tuesday.

Social isolation can actually change the expression of genes important in the growth of mammary gland tumors, according to Dr. Suzanne D. Conzen, an associate professor of medicine at the University of Chicago and the study’s lead author.

“As far as we know, this is the first assessment of gene expression in mammary glands, looking at the molecular basis for differences in tumor development under the setting of social stress,” Conzen said at a news conference Tuesday.

The findings, published in the October issue of Cancer Prevention Research, follow other studies, some in humans, that showed stress can adversely impact cancer. One study, for instance, found that stressful marriages are bad for breast cancer recovery.

Conzen and her colleagues randomly assigned mice that were genetically susceptible to breast cancer to live either in isolation or in group housing.

“We separated the mice at a very young age, just a few days after they had been weaned from their mothers’ milk,” Conzen said. “Mice are social animals. In the wild, they live in groups of three or four. They have dramatic responses to isolation.”

“What we found was the isolated mice developed larger and more breast cancers than the group-housed mice,” she added.

Three and a half weeks into the isolation, Conzen’s team measured gene expression in the animals’ mammary glands, the equivalent of the human breast. “We found very reproducible changes in gene expression [in the isolated mice]. We found genes that were turned on and turned off that had to do with metabolism,” she said. These pathways are known to contribute to increased growth of breast cancer, she added.

The isolated mice also had a higher corticosterone stress hormone response than did the group-housed mice.

The changes in the expression levels of metabolic pathway genes occurred in the isolated mice even before the tumor size differences were able to be measured, Conzen said.

So what are the practical applications of the research?

The findings may suggest molecular biomarkers, or targets, for preventive intervention in breast cancer, she said.

“Many questions remain,” Conzen added. “One of the things we did note is that the isolated animals were much more vigilant, less exploratory. They released more of a stress hormone when we added another stressor to the situation [besides the isolation].”

Thea Tisty, a pathology professor at the University of California, San Francisco, who is familiar with the findings, called the research “a very exciting beginning.”

The implication is that perceived or actual stress from outside can affect which genes get turned on or off. If the research findings bear out, it could lead to a way to catch tumors in their formation before they become tumors and suppress them, she said.

Another expert speaking at the briefing cautioned that the findings, while exciting, are only preliminary and based only on animal studies.

“This is an area that has a long way to go in terms of understanding how these factors play out in humans,” said Caryn Lerman, the Mary W. Calkins Professor of Psychiatry at the Abramson Cancer Center at the University of Pennsylvania in Philadelphia.

December 20, 2009

Scientists Discover How Chemo Can Make Women Infertile

Filed under: Women — admin @ 9:15 am

Italian researchers say they have identified the mechanism by which chemotherapy can rob a woman of her ability to have children.

Intriguingly, the scientists also found that another anti-cancer drug might counteract the negative effects of the chemotherapy drug cisplatin.

The finding, demonstrated in mice and reported in the Sept. 27 online edition of Nature Medicine, raises the hope that there might be a way to protect a woman’s fertility while she undergoes treatment for cancer but, the authors stressed, this is still a long way off.

“The extension of these findings to patients and the design of clinical trials is likely to require the development of targeted drug delivery strategies to avoid any potential interference with anti-cancer systemic therapy,” explained study author Stefania Gonfloni, of the department of biology at the University of Rome.

“I think it’s a great idea. They found a pathway that can be used as a marker to detect which drug would produce cell death as a result of chemotherapy, and they found a repair effect of a drug,” said Dr. George Attia, an associate professor of reproductive endocrinology and infertility at the University of Miami Miller School of Medicine. “[But] it’s very basic science research. It’s still early.”

Because chemotherapy affects the egg cells of the ovary, women often end up with ovarian failure and infertility as a result of cancer treatment.

“We frequently deal with women of childbearing age, and there’s a lot of concern about fertility preservation although as women get older, the chemo induces menopause,” said Dr. Igor Astsaturov, an assistant professor of medical oncology at Fox Chase Cancer Center in Philadelphia. “The standard approach now is egg collection [storing eggs for later use].”

Chemotherapy can also cause genetic defects in offspring. In particular, cisplatin, which was studied in this trial, causes specific types of chromosomal damage.

Cisplatin is primarily usually used to treat ovarian cancer, Attia noted.

In this study, Gonfloni and her colleagues showed that cisplatin promotes the death of oocytes, or female germ cells, by way of the c-Abl enzyme, a protein that, when mutated, can also cause chronic myeloid leukemia (CML).

But targeting the enzyme with imatinib (Gleevec), a drug used to treat CML, protected the oocytes from the ill effects of cisplatin.

“These results raise the possibility of protecting ovarian function during cancer treatments, thereby preserving the fertility in female cancer survivors,” Gonfloni added.

But how to use one drug without compromising the other?

“First, we have to show that imatinib can be used to prevent chemotherapy-induced ovarian toxicity without interfering with anti-cancer treatments,” Gonfloni said. “In other words, we have to prove that tumor-bearing laboratory animals can be cured with a combined cisplatin and imatinib treatment, while at the same time preserving fertility,” she explained.

“Then, for any clinical implications, it will be very important to prove the same protective effect of a specific dosage of imatinib on human oocytes cultured and challenged with chemotherapeutic drugs in vitro,” she added.

And preserving fertility is not always the right thing, Astsaturov said.

“Chemotherapy induces menopause in some hormone-dependent cancers. It has a beneficial effect because it’s withdrawing the stimulants for the cancer cells. Menopause is contributing to the cure,” he said. “It’s still debated whether we should preserve menstrual function at all costs.”

December 13, 2009

Task Force Finds Insufficient Evidence for Screening for Newborn Jaundice To Prevent a More Serious Chronic Condition

Filed under: Health — admin @ 9:14 am

According to a new recommendation from the U.S. Preventive Services Task Force, there is insufficient evidence to assess the balance of benefits and harms of screening infants for hyperbilirubinemia to prevent chronic bilirubin encephalopathy. Hyperbilirubinemia is a condition marked by a high level of bilirubin in the blood, which is often apparent as yellow-colored skin and eyes (jaundice). This recommendation and the accompanying summary of evidence will appear in the October issue of Pediatrics.

About 60 percent of all infants have jaundice, and it generally clears up without any medical treatment. Some infants are more likely to have severe jaundice and higher bilirubin levels than others. In some infants, hyperbilirubinemia may lead to chronic bilirubin encephalopathy, a rare but devastating neurological condition. The brain damage associated with chronic bilirubin encephalopathy, or kernicterus, may result in cerebral palsy, auditory processing problems, gaze and vision abnormalities, and cognitive problems. The number of children who develop chronic bilirubin encephalopathy is unknown and difficult to determine.

“There is inadequate evidence that screening all full-term and near-term infants for elevated bilirubin leads to improved health outcomes,” said Task Force Chair Ned Calonge, M.D., who is also chief medical officer for the Colorado Department of Public Health and Environment. “More research is necessary to understand how often chronic bilirubin encephalopathy occurs, its risk factors, and whether screening is associated with a reduction in chronic bilirubin encephalopathy.”

There is evidence that screening using risk factor assessment or bilirubin level measurement can identify infants at risk of developing hyperbilirubinemia, but there is no known screening test that will reliably identify all infants at risk of developing chronic bilirubin encephalopathy. Not all infants with chronic bilirubin encephalopathy have a history of hyperbilirubinemia, and not all infants who have extremely high levels of bilirubin develop chronic bilirubin encephalopathy.

In assessing the potential benefits and harms of screening infants for hyperbilirubinemia, the Task Force looked for evidence that screening reduced the number of new cases of chronic bilirubin encephalopathy. No studies have directly addressed whether screening, either risk-factor assessment or bilirubin testing, reduced the number of new cases of chronic bilirubin encephalopathy. The current evidence on screening has evaluated the effectiveness of screening to identify infants for treatment intended to reduce high levels of bilirubin.

The Task Force found that the evidence is currently insufficient regarding whether treating infants with high levels of bilirubin results in fewer children developing chronic bilirubin encephalopathy. There is a critical gap in the evidence regarding the relationship between screening infants without symptoms of hyperbilirubinemia and the desired outcome of reducing cases of chronic bilirubin encephalopathy. When the Task Force finds insufficient evidence to make a recommendation, it does not mean a clinician shouldn’t provide a service but that the evidence is lacking, and if a service is offered, patients should understand the uncertainty about the balance of benefits and harms. The Task Force recognizes that clinical or policy decisions involve more consideration than their recommendations alone, and clinicians and policy makers should understand the evidence but individualize decision-making to the specific patient or situation.

Efforts have been made by clinicians to eliminate this rare disorder by applying measures to screen for and aggressively manage high bilirubin levels. Universal screening for jaundice is widespread in the United States, and clinicians and parents should continue to work together to decide whether to screen in the face of insufficient evidence. Clinicians must remain aware that screening and resulting treatment of hyperbilirubinemia have potential harms such as weight loss, gastrointestinal problems, and disruption of the mother-infant bonding.

The Task Force is the leading independent panel of experts in prevention and primary care. The Task Force, which is supported by the Agency for Healthcare Research and Quality (AHRQ), conducts rigorous, impartial assessments of the scientific evidence for the effectiveness of a broad range of clinical preventive services, including screening, counseling and preventive medications. Its recommendations are considered the gold standard for clinical preventive services.

The recommendations and materials for clinicians are available on the AHRQ Web site at http://www.ahrq.gov/clinic/uspstf/uspshyperb.htm.

December 7, 2009

When Pounds Go, Sleep Apnea May Improve

Filed under: Health — admin @ 3:13 pm

People with sleep apnea who are also obese may triple the chances of eliminating their sleep problems by losing weight, a new study suggests.

Losing about 10 percent of their body weight was enough to bring on total or near-total remission, said Gary Foster, head of the Center for Obesity Research and Education at Temple University in Philadelphia, and lead author of the study.

“It’s been clear that obesity increases the risk of sleep apnea but less clear that if obese people or people with type 2 diabetes lost weight, it would result in significant improvements in their sleep apnea — and it did,” said Foster.

People who are overweight or obese are much more likely to have obstructive sleep apnea, a condition in which a person’s breathing stops or becomes very shallow, sometimes several hundred times a night and sometimes for as long as a minute, according to the American Sleep Apnea Association.

“The soft palate in the back of mouth falls down and blocks the airway,” said Dr. Mitchell Roslin, chief of bariatric surgery at Lenox Hill Hospital in New York City. “When you get to people with serious levels of obesity, it’s virtually impossible to find those without [this type of] sleep apnea.”

The condition can lead to cardiovascular problems, including stroke, and can raise the risk for dying prematurely.

“It really has tremendous detrimental effects on the cardiovascular system,” Roslin said.

The study involved 264 obese men and women who also had type 2 diabetes and obstructive sleep apnea. They were randomly assigned to an intensive behavioral program intended to encourage weight loss or to a less intensive set of group sessions that mainly addressed the issue of diabetes management.

After a year, those in the intensive program had lost an average of about 24 pounds, compared with slightly more than a one-pound average weight loss for the others.

Those who lost the weight also saw a substantial reduction in the number of sleep apnea episodes they experienced, with more than three times as many people in the intensive group experiencing complete remission (13.6 percent versus 3.5 percent).

“The greatest benefit was seen in men and those with severe apnea,” Foster said.

Any amount of weight loss brought on an improvement, but those who lost about 10 percent of their original body weight saw the greatest effect. “Any weight loss is good,” Foster said.

Most experts recommend 10 percent as the weight loss needed to improve sleep apnea.

However, the study also found that people whose weight remained stable experienced a worsening in their sleep apnea. Just why that occurred remains unclear.

“This is one of the first and certainly the largest study ever conducted so we’re at the point in the field, unfortunately, where we’re just describing the effect,” Foster said.

The study, published Sept. 28 in the Archives of Internal Medicine, does seem to confirm what common sense and experience have shown.

“We’ve seen that when patients gain five to 10 pounds, their sleep apnea is much worse. If they lose five to 10 pounds, the sleep apnea is much better,” said Dr. Hormoz Ashtyani, director of pulmonary critical care and sleep medicine at Hackensack University Medical Center in New Jersey. “It’s usually not a resolution, but it’s a significant improvement.”

Powered by WordPress