Thursday, January 30, 2014

Immune cells in the gut may improve control of HIV growth
June 11, 2012
University of North Carolina School of Medicine
The study was led by researchers at the University of California, San Francisco and included Kristina Abel, Ph.D., an assistant professor in the department of microbiology and immunology at UNC, at the time of the study a faculty member at the University of California, Davis.
Credit: UNC School of Medicine
The findings of a new study in monkeys may help clarify why some people infected with HIV are better able to control the virus. They also may pinpoint a target for treatment during early HIV infection aimed at increasing the supply of certain immune cells in the gut, which the study shows could be an important factor in limiting HIV growth in cells throughout the body.
The study was led by researchers at the University of California, San Francisco (UCSF) and included Kristina Abel, PhD, an assistant professor in the department of microbiology & immunology at UNC, at the time of the study a faculty member at the University of California, Davis (UCD). "The research involved a rhesus macaque model of HIV, monkeys who were infected with simian immunodeficiency virus, SIV" Abel said. "The course of SIV infection in these monkeys is quite similar to that of HIV in humans."
Both HIV and SIV infections cause severe CD4 T cell loss in the gut during early infection. As a result, the intestinal mucosal barrier, which is like the body's second skin or front line of defense against pathogens, is compromised. The "leaky gut" causes bacteria that are normally located in the gut (the normal flora) to migrate out and activate the immune system throughout the body with disastrous health consequences. "The immune activation contributes to higher replication of the virus. And so the question is, why do some patients progress from infection to AIDS faster than others?" Abel asks.
This new study looked at the balance between certain immune cell populations that might influence disease outcome. The study shows the presence of a subtype of CD4-positive immune cells called Th17 (T helper 17) cells in the gut "could influence disease outcome."
A report of the research appeared in the May 30, 2012 online issue of Science Translational Medicine.
Th17 cells are commonly found at mucosal surfaces and activate epithelial or outer layer barrier cells to secrete antimicrobial molecules, thus blocking disease-causing bacteria from entering. Abel points out that they also stimulate the production of "tight junction" proteins that keep all the cells that make up the intestinal barrier in close contact, "so that bacteria of the normal flora or their products cannot leak out."
The researchers wondered if there are more Th17 cells in the gut, would infection with the AIDS virus still have that early massive effect on gut permeability? And if you could keep the intestinal barrier intact during early infection with HIV, would it have an impact on the severity of disease progression, on having less severe disease in the long run?
Results of the study suggest that the answers may be yes. Rhesus macaques with higher numbers of Th17 cells in blood and intestinal tissue before they are infected with SIV subsequently have lower SIV viral loads. "It appears they're more able to control the infection," Abel said.
The study also found that among animals given a drug that increases regulatory T cells and thereby suppresses Th17 cell development, disease progression occurred more rapidly, and they had higher levels of SIV virus six months after infection.
"The main message of the study is that the frequencies of certain immune cell populations in the normal, still uninfected individual are important in subsequent disease progression and outcome," Abel said. "The paper also suggests that treatment aimed at increasing Th17 cells may improve the control of HIV growth by promoting an environment in which T cells having more anti-viral capabilities are produced."
The study's principal investigator was Dennis J. Hartigan-O'Connor, MD, PhD, from UCSF (now at UCD). Other investigators are Koen K.A. Rompay, from UCD; Bitoo Kanwar, from UCSF; and study senior author Joseph M. McCune, MD, PhD, from UCSF.
Support for the research came from the National Institutes of Health, the Bill and Melinda Gates Foundation, the California National Primate Research Center, the National Center for Research Resources, and the Harvey V. Berneking Living Trust.
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The above story is based on materials provided by University of North Carolina School of Medicine. Note: Materials may be edited for content and length.

Wednesday, January 29, 2014

11 Ways to Rev Up Your Metabolism

Speed Up Your MetabolismSure, your metabolism slows as you get older. But who says you have to take that sitting down? New research shows the best ways to burn more calories - faster!
Traditional wisdom holds that a sluggish metabolism is a curse of midlife, like needing reading glasses to use a smartphone or starting to worry about your retirement plan. So we fight the slowdown, eating like parakeets for a few days or launching into an intense exercise routine. When a week goes by with no miracles, we give up and resume the same bad habits - sloppy portions, half-hearted workouts, and non-petite servings of imported cheese.
Ok, put away the Brie and consider this: About 30% of your metabolism is under your control(the rest, devoted to such mundane but essential functions as digesting food and repairing cells, isn't). And as researchers get deeper into the physiology of weight regulation, they're fine-tuning their understanding of what it takes to ramp up that 30% and drop pounds. Happily, it starts with what you consume - the right foods at the right times. 

 10 Healthy Tips to Steal from Popular Diets
1. Measure Your Meals 
If simply cutting back isn't budging the scale, it's helpful to know how many calories you need each day to maintain your weight. Then, to lose pounds, you can subtract from that maintenance number. Since a woman's metabolic rate falls roughly 2% to 3% each decade, this number - alas - goes down with age. A moderately active woman in her 20s requires a daily average of 2,000 to 2,200 calories to maintain her weight. In her 30s and 40s, it drops a little to just about 2,000. After 50, it falls to 1,800.
And you? Check out the Metabolism Calculator at By plugging in your gender, age, height, weight and activity level (there's a five-point range on the site, from "inactive" to "extremely active"), you'll learn what it takes to keep the status quo. For example, a 45-year-old woman who is 5'4", 158 pounds, and moderately active will maintain her weight on 2,093 calories a day. There's been some refinement of thinking on this, but in general, to lose a pound a week, she will need to consume 500 fewer calories each day (because a pound equals about 3,500 calories), or 1,593 calories.
Try to stick to your Metabolism Calculator calories for a week without changing your exercise routine. If a pound disappears, that's a calorie-needs bull's-eye. If not, adjust accordingly.
But don't be tempted to subtract too many calories. As counterintuitive as it may seem, eating too little can slow your metabolism - by as much as 20%. "If your body thinks you're trying to starve it, it fights back by burning fewer calories," says Domenica Rubino, M.D., an endocrinologist and a spokesperson for the Obesity Society.
2. Reset Your Eating Clock 
For years, experts have said that working on smaller, more frequent meals is essential to a faster metabolism. But recent studies suggest that's no better - diet-wise - than eating three larger meals a day. There's no cut-and-dried approach, says Dr. Rubino. "The research is certainly clear that breakfast is beneficial," she says. "But beyond that, you need to find what works for you." Some people do best with six small meals a day, while others consume way too much on that schedule. Some do better with three square meals, but that can make others so hungry that they set themselves up to overeat.
Whichever plan you choose - and you may want to experiment if you've been frustrated in your past dieting efforts - be sure to keep an eye on calories and track your hunger throughout the day. And once you do decide on the best approach, start a diet log: Note meals, snacks, and your mood before you eat. "It's the number one way to be conscious of what you're taking in and what is (and isn't) working for you," says Dr. Rubino. 

Related: 15 Slimming Superfoods That Magically Help You Lose 

3. Pack on the Protein 
You need it to build muscles - the metabolic powerhouses in your body. Indeed, every pound of muscle zaps six calories a day just doing nothing, while a pound of fat burns a measly two. A 2012 review from the Netherlands found that eating a healthy amount of protein helps you drop pounds and keep them off. What's "a healthy amount"? The study authors suggest 1.2 grams of protein for each kilogram you weigh. So our 158-pound (72-kilogram) woman might eat 86 grams of protein a day - that's one egg at breakfast (6 grams), a tuna salad sandwich at lunch (16 grams), 4 ounces of fat-free cottage cheese for a snack (12 grams), and a 6-ounce chicken breast at dinner (52 grams). If she starts by loading up at breakfast, she not only will feel more satisfied throughout the day, a new study of overweight women reports, but will also snack less at night. Remember, though, "Protein doesn't have any superpowers," says Felicia D. Stoler, D.C.N., a doctor of clinical nutrition and an exercise physiologist. "Excess calories from protein will just get stored as fat."
4. Say "Yo!" to Yogurt 
This favorite snack has been associated with maintenance of a healthy weight. Now researchers believe this may be because of yogurt's bacteria. "Scientists have found that obese people have more of a certain type of bacteria that is more efficient at extracting energy from food," says Gerard Mullin, M.D., a gastroenterologist at Johns Hopkins Hospital. "It's possible that the 'good' bacteria in yogurt help counter these 'bad,' weight-gain-causing bacteria."
5. Sprinkle on Spicy Extras 
Chili peppers, ginger, and turmeric have all been found to have a beneficial, albeit small, effect on metabolism. Use them often-beyond the boost, "You'll be getting phytonutrients, and they make meals more flavorful," Stoler says. 

Related: Little Every Day Tricks To Burn Extra Calories
6. Be Cardio Smart 
Aerobic exercise is like one of those store sales at which you buy one item at full price and get a second item for 50% off: There are the calories you burn while working out and, because your metabolic rate stays elevated, the extra calories you continue to burn while lounging on the chaise. Researchers found that about five sessions of moderate cardio per week - each lasting between 20 and 45 minutes - increased daily metabolism by an average of 109 calories in women. So even on the days the women weren't exercising, they enjoyed an afterburn.
Need more motivation? Even without dieting, cardio can lead to weight loss: In recent research from the University of Kansas, overweight women doing moderate cardio five days a week dropped 5% of their body weight in 10 months - without changing a thing about their diets.
To make sure your own workout is sufficiently strenuous, try to talk during it - having a short conversation should be possible, but not easy. Or, you can find your target heart rate here. For each age group, the rate is given as a range, so you may want to start with the lower number (especially if you're new to exercise or haven't done it in a while) and work your way up.
Try to get your workout to 30 minutes a day, and don't worry - it'll pay off: In a Danish study, previously sedentary volunteers instructed to exercise for half an hour lost just as much weight as those who worked out for an hour. (The researchers speculate that 30 minutes likely felt so doable and rewarding to those participants that they went on to do more physical activity in other ways not connected to the study.)
7. "HIIT" It 
High-intensity interval training has become the rage for a very good reason: Sprinkling just five 30-second extra-hard intervals into your normal cardio routine can torch as many as 200 additional calories in your workout. (You can do anything for 2 minutes!)
Or you can alternate intensities, going faster for one minute and then slower for the next. There's an unexpected perk to this approach, says Wayne L. Westcott, Ph.D., a professor of exercise science at Quincy College in Quincy, MA: The recovery minute feels so good to people that "time becomes their friend for that minute. It becomes more like a game and less like a workout." Research backs this up: A study from Liverpool John Moores University reports that recreational exercisers who ran using HIIT found it significantly more fun than just slogging along.
8. Get Muscular 
At around age 30, we start morphing into marshmallows as we lose about 5% of our muscle mass per decade. But maintaining and building muscle revs our metabolism. Even a simple weight-training program of three 25-minute sessions a week can keep your muscles toned - and burn 100 calories per session. The happy result: You could blast a third of a pound of pure fat in a month or 4 pounds a year.
There's no need to go to the gym. Exercises that rely on body weight, such as push-ups, tricep dips, wall sits, squats, and lunges, can be just as effective as those that use weights or machines. For how-tos, check out the exercise library at the American Council on Exercise.
9. Cure Sitting Sickness 
If you make phone calls for one hour at your desk, you'll burn 15 calories, but if you do it while standing up and pacing, you'll blast 100 calories. It's called NEAT - Non-Exercise Activity Thermogenesis - and ongoing research at the Mayo Clinic has found that we can burn up to an additional 800 calories a day simply by getting off our keisters and moving around more. Not only does NEAT help drop pounds, but it also may have a greater impact on longevity than standard exercise. A large study from the American Cancer Society found that women who sat for more than six hours a day were 37% more likely to die during the course of the 14 years of research than those who were sedentary fewer than three hours a day. This association remained virtually unchanged even when the sitters were devoted exercisers.
Some of the ways to incorporate more activity into your day are well known - taking the stairs instead of elevators, walking to colleagues' desks rather than e-mailing them. But you can also seed mini workouts into your daily life. "Do squats or lunges while waiting for the copier to warm up," suggests Stoler. At home, get in some tricep dips while the dryer is finishing its cycle or the coffee is brewing.
10. Call "Om" 
Add a bigger belly to the list of miseries chronic stress can inflict. Even if you're not eating more, changes in the way your body stores fat may cause thickening. In a just-completed study, for example, researchers found that a woman caring for a loved one with dementia had a bigger waistline than her less stressed counterpart, although both were eating the same large amounts of high-fat, high-sugar comfort foods.
It's the stress hormones and peptides at play here, which become elevated when we're under pressure. But several studies have shown that practicing yoga can tame anxiety - and also lower levels of these chemicals.
11. Melt Fat Mindfully 
A study in which women practiced mindfulness techniques (meditation, yoga, and more) for four months found those who showed greatest improvement in awareness of thoughts and feelings reduced their abdominal fat the most. And such focus, experts say, may be just what you need to embark on a bigger metabolism-revving program.