0 comments Monday, August 11, 2008

Researchers at The Evergreen State College in collaboration with the U.S. Department of Agriculture at Texas A&M have been working to increase food safety by reducing the populations of E. coli in the guts of sheep and cattle. The goal of the research is to increase understanding of the complex predator-prey relationship between bacteria (the prey) and bacteriophages (the viral predator). The research could lead to safer food.

E. coli O157:H7 is a dangerous bacterial food pathogen that occurs naturally in the guts of livestock without making them sick. E. coli is easily passed from farm animals to humans. The bacterium causes food poisoning, sickness, and sometimes death in people who eat tainted meat or contaminated produce or water.

Andrew Brabban and Betty Kutter, microbiologists at Evergreen State College in Olympia, Washington, have been studying tiny E. coli predators known as bacteriophages, which attack E. coli bacteria. The Evergreen State phage biology lab was established in 1973 and together Kutter and Brabban have more than six decades of research experience on phages.

Brabban, Kutter, and colleagues have uncovered bacteriophages that attack various strains of E. coli naturally in cattle or sheep's stomach. Recent results appeared under the title "Prevalence of Escherichia coli O157 and O157:H7-infecting bacteriophages in feedlot cattle feces" in the October issue of Letters in Applied Microbiology. The research is funded by the U.S. National Institutes of Health, Phage Biotics, the National Cattlemen's Beef Association and the U.S. Department of Agriculture.

By using phage as a natural predator, it may be possible to better target and tame E. coli and increase the safety of food. Using bacteriophages provides a potentially cheap and broadly applicable way to treat cattle that offers advantages over traditional antibiotics.

Phage treatment is more specific to E. coli, which means it is less likely to encourage resistance in other harmful bacteria and less likely to kill useful bacteria. Also, much like the bacteria, the bacteriophage is easily transferred from one infected individual to another, resulting in a more robust solution to E. coli infections.

Economic impacts could also be significant. "E. coli contamination results in waste of meat, and ultimately wasted meat costs consumers," says Brabban. "Hundreds of millions are also spent to treat E. coli infections," he adds.

But while economics are important, healthier food is the top priority of the research. "It would be very rewarding if we could come up with an increased understanding or an application that leads to safer food down the line," says Brabban. "We all would like food to be safer."

The Evergreen State College
http://www.evergreen.edu

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A pre-cancerous condition linked to chronic acid reflux often gets overlooked. Can the medical community do a better job intervening? Researchers from the Hutchinson-MRC Research Centre in Cambridge think so.

In a review published in the inaugural issue of Disease Models & Mechanisms (DMM), experts on a disease known as "Barrett's oesophagus" discuss how "Barrett's" presents unique challenges in diagnosis and treatment. They cite key factors which make this illness difficult to detect, and suggest how scientists and doctors can team up to improve the odds of intervention.

Doctors want to understand more about this condition because patients with Barrett's have 30 to 125 times increased risk of an often fatal cancer of the oesophagus. One of the most common indicators of Barrett's is severe and chronic acid reflux. The authors of the review article discuss several reasons why most Barrett's cases are undiagnosed. The wide-spread availability of over-the-counter antacid medications may contribute by suppressing symptoms such that only the most severe and persistent cases of acid reflux are recommended for screening. Additionally, in order to screen for Barrett's, the oesophagus must be examined with a small light and camera (endoscope) which is not a routine procedure.

The biological basis of Barrett's is an abnormal change, or dysplasia, in the oesophagus. Normally, the oesophagus is lined with flat-shaped cells known as squamous cells. However, in patients with Barrett's, the cell lining consists of rectangular-shaped columnar cells. This process of normal cells morphing into abnormal cells is common to several types of cancer, not just oesophageal cancer. Thus, a greater understanding of Barrett's can also lead to potential therapies for similar pre-cancerous conditions.

In order to advance the diagnosis of Barrett's oesophagus, researchers recommend identifying standardized indicators which can be used to identify the presence of Barrett's as well as predict the likelihood that it will progress into cancer. Additionally, they recommend developing less costly screening methods to allow routine checks for Barrett's in patients with acid reflux. They point out the need for developing laboratory animal models of this disease in order to study the underlying molecular mechanisms of Barrett's, as well as to test potential novel therapies.

The review was written by Massimilian di Pietro, Christopher J. Peters and Rebecca C. Fitzgerald of the Hutchinson-MRC Research Centre in Cambridge, UK. The report was published in the inaugural July/August issue of a new research journal, Disease Models & Mechanisms (DMM), published by The Company of Biologists, a non-profit based in Cambridge, UK.

The DMM website is located at: http://dmm.biologists.org

0 comments Thursday, July 24, 2008

You know it all too well. Heartburn. That fiery sensation that grabs hold of your lower chest after you eat something you know you shouldn't have. What often follows is that sour or bitter taste of acid reflux in your throat and mouth that can last minutes (if you are lucky) or hours (if you are not).

Yes, millions of us are familiar with the discomfort of heartburn, a condition in which stomach acids back up into the esophagus. The good news is that heartburn is largely avoidable if you steer clear of the top 10 heartburn foods. It also helps to avoid certain classic heartburn-inviting situations.

From coffee and liquor to tomatoes and grapefruit, experts tell WebMD that certain foods are known heartburn triggers.

Here's what you need to know about the top 10 heartburn foods.

Heartburn and Tangy Citrus Fruits

Oranges, grapefruits and orange juice are classic heartburn foods. "These are very acidic," says Robynne Chutkan, MD. Chutkan is the founder of the Digestive Center for Women in Chevy Chase, Md. and a gastroenterologist at Georgetown Hospital in Washington, D.C. "As a result of being so acidic," she says, "they are likely to cause heartburn, especially when consumed on an otherwise empty stomach."

Heartburn and Tomatoes

While they might be chockfull of healthy nutrients like lycopene, Chutkan tells WebMD that tomatoes are also highly acidic and likely to cause heartburn in those who are prone to it.

The acid antidote may be a sour ball, according to Daniel Mausner, MD. Mausner is the section head of gastroenterology at Mercy Medical Center in Rockville Center, N.Y. "Things that promote saliva -- like sour balls -- are good for acid reflux," he says, "because saliva neutralizes the acid that comes up from your stomach."

Heartburn and Garlic and Onion

Bonnie Taub-Dix, MA, RD, says, "Some people with heartburn do not do well with either garlic or onion." Taub-Dix, a spokeswoman for the American Dietetic Association, is a nutritionist in private practice in New York City and Woodmere, N.Y. "It's all very individual," she says. For avoiding heartburn, she offers the following suggestion: "Keep a food log to help you track the foods that are your heartburn offenders, and try to develop a list of safe foods." Foods like broiled chicken, baked sweet potatoes, toast, or cottage cheese, she says, are on the safe side of the heartburn food list.

Heartburn and Spicy Foods

Pepper, Mexican food, chili, and any other food that is loaded with pepper or other spices can trigger heartburn, says Deepa A. Vasudevan, MD. Vasudevan is an assistant professor of family medicine at The University of Texas Medical School at Houston. He tells WebMD that avoiding heartburn isn't necessarily a matter of all or nothing. "If spicy food triggers your heartburn, avoid it. Then slowly reintroduce milder versions of whatever you like."

Heartburn and Peppermint

Chutkan says that while many people think peppermint is soothing for the tummy, it is actually a heartburn trigger food. Her advice? Skip the after-dinner mints -- especially after a rich meal. "They may be good for your breath on a date," she says, "but they are not so good if you are prone to heartburn."

Peppermint may increase your chances of heartburn because it relaxes the sphincter muscle that lay between the stomach and esophagus. This allows stomach acids to flow back into the esophagus.

Heartburn and Cheese, Nuts, Avocadoes, and a Juicy Rib Eye

What do these foods have in common? They are all high in fat, according to Chutkan. "These foods may not get as much press as acidic foods when it comes to heartburn," she says, "but they can be major triggers." Here's why: Fat slows down the emptying of the stomach, so there is more opportunity for a big distended stomach -- which increases pressure on the esophageal sphincter -- to make heartburn more likely.

Chutkan says that doesn't mean you can never have those foods again. "Don't have a cheese plate at the end of a meal," she suggests. "Instead, eat it early in the day when you are not already full." Remember, a serving of cheese is roughly the size of two dice.

Heartburn and Alcohol

Wine, beer, or your favorite cocktail can all trigger heartburn, says Chutkan, especially when they are imbibed with a large meal. "If you have a meal of steak, creamed spinach, and lobster bisque and then alcohol on top of that," she says, "you may be in for it."

Taub-Dix agrees. "A glass of red wine may not be a big deal on its own," she points out. "But if you also have tomato sauce on your pasta and a glass of orange juice in the morning on an empty stomach, it could be a problem." Like peppermint, alcohol opens the sphincter, allowing the acid free range.

Heartburn and Caffeine

Coffee, soda, tea, iced tea, and any other food or beverages that contain caffeine are big offenders. But java junkies don't have to give up their Joe forever, Chutkan tells WebMD. "It's not 'no coffee ever' if you have heartburn. It's about cutting down and paying attention to portion sizes. A Starbucks tall," she explains, "which is their version of a small, is like three cups of coffee. Some people tell me they drink two cups of coffee a day and that they get it at Starbucks. That's like six cups a day."

If you have heartburn, you can likely consume a 3- or 4-ounce cup of coffee each morning with no problem. But if you guzzle coffee all day long, then, yes, heartburn is a consequence

Heartburn and Chocolate

Sure, it can be loaded with caffeine, but chocolate can also be a heartburn food in and of itself. "Pack up all of your chocolate and give it to your gastroenterologist for safekeeping if you have heartburn," Chutkan says. Chocolate relaxes the sphincter, allowing stomach acids to flow back into the esophagus, she says.

Heartburn and Carbonated Beverages

"Carbonated beverages cause gastric distension," Mausner says. And if your stomach is distended, this increases pressure on the esophageal sphincter, promoting reflux." He tells WebMD that people with heartburn may be wise to steer clear of pop and other carbonated beverages.

Heartburn Foods: Find Your Triggers

Taub-Dix's advice is to use the above list as a guide to help you figure out your heartburn foods and heartburn trigger situations. And remember, she cautions, even if your favorites are not on this list, you don't necessarily have a free pass. "Too much of any food can trigger heartburn," she says. It's not just what you eat; it's how much you eat and when you eat it. "Consuming a large meal right before you lie down," she says, "will likely cause heartburn even if it doesn't include any of these heartburn foods."

source: WebMd

0 comments Tuesday, July 1, 2008

Persons with irritable bowel syndrome (IBS) can relieve their symptoms as effectively by following a self-administered, at-home cognitive behavioral program as they can by undergoing a 10-week in-office program administered by a trained therapist, a new pilot study has shown. The findings are important because there are no reliable medicines available to treat successfully the full range of symptoms of this chronic, often debilitating, disorder that affects an estimated 14-24 percent of women and 5-19 percent of men in the U.S.

The study is posted online on the Clinical Gastroenterology and Hepatology's Web site and will be published in the journal's July 2008 issue.

Jeffrey M. Lackner, Psy.D., assistant professor in the Division of Gastroenterology in the University at Buffalo School of Medicine and Biomedical Sciences and director of its Behavioral Medicine Clinic at the Erie County Medical Center, is first author.


"The value of this study is that it shows that patients can learn relatively simple self-care skills to take control of symptoms that are resistant to existing medical treatments," said Lackner. "This is a dramatic example of the complexity of brain-gut interactions."

IBS is characterized by chronic abdominal pain and discomfort, diarrhea and/or constipation. Cognitive behavioral therapy (CBT) has been shown to improve symptoms, quality of life and psychological stress, but there is a shortage of trained CBT therapists, which has created long waiting lists.

The treatment also is expensive and time consuming, requiring 10-12 in-office sessions, a schedule many patients are unable or unwilling to maintain. In addition, IBS specialty clinics are rare, so patients are deprived of the state-of-the-art treatment available at UB.

To help solve these problems, Lackner and colleagues designed a primarily self-administered treatment program that patients can learn at home, using self-study materials, supplemented by four in-office counseling sessions.

"Patients can follow a program like this at their own pace and on their own time," Lackner noted, "and perhaps most important, they can learn these skills in the environment where symptoms are most likely to occur. It also requires less travel, which makes it convenient for patients with busy lifestyles and for those in underserved and rural areas."

The researchers tested the program's effectiveness in a pilot study involving 75 IBS-diagnosed patients who were randomized to one of three groups: a standard 10-session therapist-administered cognitive therapy group (CBT); a "minimal-contact" CBT group (MC-CBT) that included the home-based program and a wait-list group (WL). This last group simply monitored their gastrointestinal symptoms daily.

All participants were interviewed two weeks after the end of the 10-week treatment period to gather information on overall relief of symptoms and improved quality of life.

Patients in both therapy groups reported clinically significant relief of symptoms: 60.9 percent in the CBT group and 72 percent for MC-CBT. Only 7.4 percent of the wait-list group reported improvement. Patients in both treatment groups also reported significant improvement in quality of life.

"The finding that a self-administered approach can be successful in reducing IBS symptoms is important at this point in time, when few validated therapies are available for patients," said Lackner.

"Further research is needed to establish the therapeutic potential of this novel approach to managing IBS, as well as to understand how these treatments work and the conditions under which they are most likely to achieve the desired effects."

Source: Lois Baker
University at Buffalo

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A nuclear medicine imaging test was used to confirm that children with respiratory problems may be more likely to develop gastroesophageal reflux disease, according to researchers at SNM's 55th Annual Meeting. The nuclear imaging technique, known as scintigraphy, was also shown to be more effective in detecting the disease in these children than traditional barium X-ray technology. The results indicate that scintigraphy could become an important diagnostic tool for detecting reflux disease, a serious condition that can lead to chronic chest pain, vomiting, weight loss and lung impairment in children who suffer from it.

"Unfortunately, reflux disease is a common problem in children, especially for those with respiratory problems," said Wajiha Nasir, a researcher at the Nuclear Medicine Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. "If left untreated, the disease can seriously impede children's health, growth and development, not to mention their quality of life. Our results show that scintigraphy is highly effective at safely diagnosing the condition."

Reflux disease occurs when the esophagus becomes irritated or inflamed by stomach contents. The stomach produces hydrochloric acid after a meal to aid in the digestion of food. Normally, a ring of muscle at the bottom of the esophagus, called the lower esophageal sphincter, prevents the acid from going back up the esophagus. With reflux disease, however, the sphincter relaxes between swallows, allowing stomach contents and corrosive acid to well up and damage the lining of the esophagus.

The chronic condition affects up to a third of adults, and many infants and children also suffer from it. Some of these children outgrow the condition as their digestive systems mature, but many do not. Researchers have long suspected that children who have respiratory problems such as asthma might also be more susceptible to reflux disease.

Scintigraphy is a diagnostic test in which a two-dimensional picture is obtained through detection of a radiation emitted by a radioactive source given to the body. In this study, 55 children aged six months to 12 years who had asthma or lower respiratory tract infections were orally administered a commonly used radioactive imaging agent that was then detected through scintigraphy technology.

The test detected reflux disease in 66.6 percent of the children, revealing a strong association between reflux disease and respiratory disease. In addition, scintigraphy proved more effective at detecting the disease than traditional barium x-rays. Children in the study who exhibited reflux disease were given medication to treat reflux. At a three-month follow-up visit, most of the children's symptoms had improved after receiving the medication.

"Scintigraphy is one of the simplest radionuclide tests to administer, with a very low radiation burden," said Nasir. If performed routinely for children suffering from bronchial asthma and recurrent respiratory tract infections, this test could get children the treatment they deserve."


Source: Amy Shaw
Society of Nuclear Medicine

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To survive tough times, cells sometimes resort to a form of self-cannibalism called autophagy. But as Hashimoto et al. reveal, autophagy can have a down side, destroying the pancreas by prematurely activating a digestive enzyme.

In autophagy, a vesicle swallows a portion of cytoplasm and ferries it to the lysosome for digestion. The process is often beneficial, allowing hungry cells to recycle molecules, for example. However, the researchers previously discovered that in mice with pancreatitis the level of autophagy in pancreatic cells surges. Pancreatitis occurs when the enzyme trypsin dissolves cells from within. Normally, pancreatic cells fashion and discharge an inactive form of trypsin called trypsinogen, which remains inert until it reaches the small intestine. But if trypsinogen converts to trypsin before its release, it can damage or kill a pancreatic cell. Hashimoto et al. tested whether autophagy promotes this early activation by delivering trypsinogen to the lysosome, where enzymes turn it on.

The researchers gave mice injections of the compound cerulein, which spurs pancreatitis. Control animals suffered severe damage to the organ, which harbored numerous deteriorating cells. But rodents that lack a gene necessary for autophagy displayed almost no symptoms. To determine whether autophagy promotes trypsinogen activation, the team dosed pancreatic cells from both types of mice with cerulein. Cells from the autophagy-impaired animals carried much less activated trypsinogen than did cells from controls.

In rodents capable of autophagy, cerulein injections triggered much higher levels of trypsin activity in pancreatic tissue than did shots of saline, confirming that autophagy switches on the enzyme. The study is the first to reveal that autophagy can initiate a disease. The next step, the researchers say, is determining what triggers pancreatic cells to start eating themselves.


Source: Sati Motieram
Rockefeller University Press

0 comments Tuesday, June 10, 2008