Stem cells in the gut of Drosophila divide in response to food. Photo courtesy of John Tann

Researchers investigated how stem cells in the gut of the fruit fly respond when different amounts of food are present. They found that when food is abundant, stem cells in the gut divide more rapidly, increasing the size of the gut as long as food continues to be available. When food is removed, the cells stop dividing and the gut shrinks down again.

“The real surprise was that the fruit fly intestine is capable of secreting its own insulin,” said principle investigator David Bilder in a press release. “This intestinal insulin spikes immediately after feeding and talks directly to stem cells, so the intestine controls its own adaptation.”

Insulin is also the primary signaling molecule for converting blood sugar into usable energy in muscles, and storing it as fat.

What the current findings mean for human physiology or chronic overeating is still unknown, but it raises many new questions regarding the role of intestinal stem cells and metabolism.

Image courtesy of cessable

For better quality of life as you age it’s important to keep the fire burning, according to a new study published in the Journal of the American Geriatric Society.

Researchers at the Stein Institute for Research on Aging at UC San Diego looked at data from 1,235 post-menopausal women participating in the Women’s Health Initiative (WHI) study. The women were asked questions about their health, both physical and mental, as well as sexual activity and functioning.

Though aging was associated with an expected decline in physical health and sexual frequency, overall sexual satisfaction did not decline with age. Additionally, having a satisfying sex life was also associated with indicators of successful aging and high quality of life.

“Feeling satisfied with your sex life—whatever you levels of sexual activity—is closely related to your perceived quality of life,” says Wesley K. Thompson, co-author of the study. “While we cannot assess cause and effect from this study, these results suggest that maintaining a high level of sexual satisfaction may positively reinforce other psychological aspects of successful aging.”

Is it time to start bringing home flowers and candles in addition to the extra calcium and fish oil supplements? Let’s hope so.

By one estimate, there are 10 million alcoholics in the US. Photo Credit: Ralf Roletschek

Joseph McHugh is an artist who lives in San Francisco. Like his father before him, Joe had always been a drinker. But recently, it started to pick up.

“It sort of got out of control,” he says. “It wasn’t starting at five o’clock, it was starting at noon, when I’d have a couple shots and so forth.”

He was having blackouts, he says. He remembered nothing, but people would tell him stories of what he’d done. “Like what?” I ask him.

“Things I don’t want to even mention, ok?”

What brought McHugh VA Medical Center in San Francisco was a heart attack. It literally terrified him into sobriety. He's been dry a month now, slogging through recovery with other men whose lives have also become simply untenable.

Listen to the QUEST radio story The Search for Alcoholism's Miracle Drug

McHugh’s story is a familiar one to doctors who treat alcoholism, like Peter Banys, Director of Substance Abuse Programs at the VA.

“It's always a crisis,” Banys says. “And it can be a marital crisis, a family crisis, or job termination.”

Alcoholism is a very treatable disease, says Banys. Because of all the recent research, people like McHugh have more options than ever, including AA, therapy, and medication, which can be effective in preventing relapse.

Still, there are some challenges. First of all, the meds are a tough sell, Banys says. He says his patients often think of their alcoholism as a moral weakness.

“One of the things we hear a lot,” he says, “is I don’t want to depend on a drug. They’ve been depending on a drug for 25 years, they don’t want to depend on ours.”

Another problem is that drugs that once seemed promising have often fallen short.

Take Naltrexone, which was approved in 1995. Naltrexone blocks the brain’s opioid receptors, which make alcohol feel good.

“That was the great hope,” says Banys. “It kind of crumbled in our hands.”

On many people, Natrexone has no effect all. They’re just wired differently.

And that’s proven to be a useful insight.

“One of the things that we have to make clear is that alcoholism is almost certainly not a single disease or disorder. I believe that in the near future, we will be talking about “the alcoholisms.”

The fact of these “alcoholisms” means that researchers are now targeting specific kinds aspects of brain chemistry that might be involved in alcoholism.

Howard Fields directs Human Clinical Research at the Gallo Center in Emeryville, an institute devoted to alcoholism and addiction, affiliated with The University of California, San Francisco.

What interests him is something familiar to many of us: Impulsivity. Different people are impulsive to different degrees, just like rats, and other animals. From an evolutionary standpoint, this makes sense.

“You want someone who would throw themselves on the hand grenade and save the lives of other people,” says Fields. “The same people who wind up in prison might be completely different in a battlefield situation. They might be the heroes.”

But in regular life, impulsivity can be a dangerous trait to have, says Fields. “If you score high for impulsivity, you are at greater risk to actually become an abuser or an addict. There’s no question about that.”

Fields says that in some people, impulsivity can be traced back to a specific gene. If you have it, you’re more likely to be impulsive. And it turns out, there is already a drug on the market that targets a function of this gene. It’s called tolcapone, and it’s prescribed to people with Parkinson’s disease.

So what Fields aims to find out is whether tolcapone might actually make people less impulsive. And if that’s true, whether it can help people limit their drinking. This research is now in human clinical trials.

Of course, even if the drug works for some people, it won’t work for everyone. The fact that there are “alcoholisms,” as Peter Banys put it, means that there may never be a single miracle drug.

But whatever the future holds, the goal of treatment will always look more or less the same: More people like Joseph McHugh, who have made the life-changing decision to get and stay sober.

McHugh says it’s hard to know what things will be like, once he’s out of rehab and back with his family. But he’s optimistic.

“I’m sort of glad that everything is where it is now. Because it is a change. It’s a necessary change."

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The nose of the star-nosed mole is much more sensitive than the human hand. Credit: Dr. Ken Catania, Vanderbilt University

Pain is the most common reason for trips to the doctor's office. So it makes sense that pain treatment is a huge part of our healthcare system, costing more than 100 billion dollars a year. But how exactly pain works is still a mystery in many ways.

Like any normal 9-year-old, Maddie Burkhardt was playing outside with her friends last summer, racing around in a pedal go-cart.

"And my foot slipped and it went under the go-cart. Like it got bent backwards," she says.

Maddie broke a bone in her foot. So, her mom, Danielle, took her to see a podiatrist, who put her in a series of casts.

"And every time he took the cast off, he said 'ok, you should feel much better now.' And she was just like 'no, it's killing me," says Danielle.

As the weeks went by, it became clear that Maddie's pain wasn't normal. "She would not allow anything to touch her foot at all. And we didn't really know what was going on," says Danielle.

Listen to the QUEST radio story The Science of Pain

Even a light touch, like the wind blowing, was incredibly painful. "It felt like there was knives in my foot. Like a big elephant smashing on your foot or something," says Maddie.

Maddie was diagnosed with complex regional pain syndrome and ended up in a special treatment program at Lucile Packard Children's Hospital in Palo Alto.

Dr. Elliot Krane, who heads the program, says "most of the time, pain is the signal that there's a problem and it's a useful sensation to have and a protective one."

But sometimes, our body's warning system goes haywire, like in Maddie's case. Nerve cells send out pain signals even when there's no reason to.

"It's a terrible pain problem," says Dr. Krane. "And it's one that we really don't understand the origins of. And because we understand so little about it, our therapy of it is also very rudimentary.

Krane says Maddie, like most patients, went through a slew of treatments, like physical therapy and pain medication. It took months to recover. "I can't exactly run really yet, but I can walk faster and I can play with my friends and do a lot more," Maddie says.

For the most part, doctors rely on opiates like morphine to control pain. But those drugs aren't very targeted. The challenge is that pain is very difficult to study. "There's other things and other processes in the body which are measurable in some objective fashion: heart rate, blood pressure, temperature. But how do you measure pain?" asks Dr. Krane.

Looking to Nature for Solutions

In a lab at the University of California-Berkeley, Diana Bautista has the same questions about pain. "Many people are trying to figure out how to do this. And we decided to look to nature to solve this problem."

Bautista is an assistant professor of biology at the University of California-Berkeley. She's peering into a large plastic tub filled with dirt.

A star-nosed mole at UC Berkeley. Photo: Kristin Gerhold, Bautista Lab.

"So, if you look here in the corner of the dirt, you can see that there's a star-nosed mole. Pretty interesting looking, right?"

Star-nosed moles have a very unique look. Their large pink nose has 22 finger-like tentacles that they use to feel for food in the dark tunnels where the live.

"What we don't see, that you need special high-speed video to see, is that they're actually tapping very rapidly the surface," says Bautista.

Compared to our fingertips, the mole's star has 10 times more nerve cells. "It's much more sensitive than the human hand."

That lack of sensitivity in human skin makes it difficult to study pain, because our nerve endings are so spread out.

We also have about 20 different kinds of nerve cells. Some detect pain, some detect light touch. Others detect hot and cold. "And so it's very difficult to study one in isolation or to separate the pain cells from the light touch cells."

That's where the star-nosed mole comes in. Its star is densely packed with light touch cells, but not a lot of pain cells. So Bautista says, studying tissue samples of the mole's star can reveal the differences between nerve cells.

"How does one cell feel the prick of the pin and the other feel the feather? We don't know what happens in those nerve endings," says Bautista.

Bautista says knowing what happens in normal nerves can tell a lot about when nerves don't work normally – like when diabetes patients experience numbness or cancer patients have hypersensitivity. That comes down to the biochemistry inside the cells. For that, Bautista is also studying another organism.

Peppers Targeting Nerve Cells

"These are Szechuan peppers that are from the Chinese prickly ash," Bautista says, handing me the peppercorns.

"Chew them a little bit in the front of your mouth."

As I chew, my tongue becomes slightly numb. "It feels like a little buzzing, tingling sensation," says Baustista.

The peppercorns aren't hot, but they do have chemicals that are working on my sense of touch. "We know that they target special receptors and cause those nerves to be excited just as if somebody was tickling your tongue," says Bautista.

That's a trick that humans could copy. "By indentifying the molecular mechanisms, we could really go in and design better drugs and come up with better therapies and alternatives for treating conditions like chronic pain," she says.

Bautista hopes the research will lead to more targeted pain drugs, so patients like Maddie Burkhardt will have an easier recovery.

Check out the star-nosed mole in action:

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How do we make healthy eating cool? Image courtesy of f_mafra.

People who immigrate to the United States from traditionally healthy cultures usually develop Western disease patterns within one or two generations. Since genetic changes cannot occur this rapidly, environmental factors, particularly diet, are considered to be primary the reason for the shift.

While it has been proposed that dietary changes are the result of having access to less healthy foods, new research suggests that poor food choices are often made not from preference but from pressure to fit in as an American.

In a new study to be published in the upcoming issue of Psychological Science, researchers from Stanford and UC Berkeley explored the eating choices made by Asian-American and white college students when put in situations that threaten their American identity.

The first part of the experiment asked students to write down their favorite foods, but first prefaced some of the students with the question, "Do you speak English?" All the students could speak fluent English, but of the Asian-American students that were asked the question 75% included a stereotypical American food in their food preferences, compared to 25% who had not been asked the question. There was no difference in preferences of white students with or without the question.

To test if cultural pressure affects eating habits directly, researchers performed a similar experiment but offered students dishes from typical American and Asian restaurants. Before the experiment, however, some students were told, "Actually, you have to be American to be in this experiment."

Asian-American students who were asked the question were more likely to choose the American food options than the students who were not asked the question. Subsequently their choices were less healthy and they ate an extra 182 calories in the meal.

Attitudes about food and social pressure can greatly impact eating habits, and this study is consistent previous findings that overweight people tend to have overweight friends. Bad eating habits aren't just individual choices, but reflect societal pressures and group psychology.

But the question remains, how do we make healthy eating cool?

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"Minuscule" amounts of iodine-131 was found in milk from Washington state. Image courtesy of stevoarnold.

Reuters reports that trace amounts (0.8 pCi/L) of radioactive iodine-131 was found in milk from cows in Washington state, though officials stress this is nothing to be alarmed about.

"These types of findings are to be expected in the coming days and are far below levels of public health concern, including for infants and children," said the Food and Drug Administration and the Environmental Protection Agency in a joint statement.

Though the levels found in the US are 5,000 times below the FDA's standard, this particular isotope of iodine is not normally present in milk. When milk is contaminated, iodine-131 can accumulate in the thyroid and lead to cancer.

US officials have been monitoring radiation levels in milk and drinking water since the radiation leak at Japan's Fukushima Daiichi nuclear plant after the March 11 earthquake.

Fortunately the half life of iodine-131 is quite short, only 8 days, meaning the vast majority of the dangerous isotope should be degraded in 2 weeks time so long as there is not additional exposure.

US citizens are at extremely low risk of radiation exposure due to the events in Japan, but officials will continue to monitor the situation.

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Prudent, persistent children ultimately live longer than their happy-go-lucky peers. Image courtesy of Meanest Indian.

Happiness is tied to good health later in life, but childhood happiness does not predict longevity—in fact it does the opposite, according to a new report.

Howard Friedman and Leslie Martin, researchers from UC Riverside, analyzed and supplemented data collected by the late Stanford University psychologist Louis Terman in a new book titled The Longevity Project: Surprising Discoveries for Health and Long Life from the Landmark Eight-Decade Study.

Terman followed 1,500 children from age 10 beginning in 1921, tracking them through their lives and collecting many details and data points including work life, relationships, personality, hobbies, pets, education and professional successes.

“Probably our most amazing finding was that personality characteristics and social relations from childhood can predict one's risk of dying decades later,” Friedman said in a press release.

But the findings aren't what most people would expect. The researchers discovered that the most cheerful children ended up taking more risks with their health as they got older.

“We found that as a general life orientation, too much of a sense that 'everything will be just fine' can be dangerous because it can lead one to be careless about things that are important to health and long life,” said Friedman. “Prudence and persistence, however, led to a lot of important benefits for many years.”

Other of Friedman's findings are counter to conventional wisdom as well, like the idea that less work and stress contributes to a longer life. Those who were the most productive and committed to their jobs lived significantly longer than those who took it easy.

“It turns out happiness is not a root cause of good health. Instead happiness and health go together because they have common roots,” according to Friedman.

Friedman's work implies that good decisions are more important than disposition for health and longevity, meaning that any one can learn to make better choices and take steps to lengthen their life.

Workaholics rejoice!

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Shifting focus toward healthy habits and away from body size may be a more effective strategy for long-term health, but fat loss may still be a worthwhile target. Image courtesy of Kyle May.

The number one public health message today, as seen in the recent announcement of the new USDA Dietary Guidelines, is that we all need to lose weight. But a new review published in Nutrition Journal suggests that this message may be doing more harm than good.

Co-authors Linda Bacon, an associate nutritionist in the UC Davis Department of Nutrition, and Lucy Aphramor, an NHS specialist dietician and honorary research fellow at the Applied Research Center in Health and Lifestyle Interventions at Coventry University in England, argue that most of the assumptions made about the link between body fat and health are not substantiated, and that a more effective approach would be to emphasize healthy habits focused less on body weight.

“The weight-focused approach does not, in the long run, produce thinner, healthier bodies,” Bacon said in a press release. She suggests that while overweight and obesity are often linked to poor health outcomes, these ties are not as strong as most people assume and that the evidence suggests underlying bad habits cause both disease and weight gain. If this is the case, body fat itself may not be a cause but a symptom of poor health, and therefore targeting weight loss specifically may not be beneficial.

The authors note that evidence indicates that long-term weight loss is very difficult and often impossible to achieve for most people. They also point out that removing body fat without a change in lifestyle, as in cases of liposuction, create no measurable health benefits. Moreover, a focus on body weight instead of health changes can often lead to both physical and psychological problems.

“It's the unintended negative consequences that are particularly troubling, including guilt, anxiety, preoccupation with food and body shape, repeated cycles of weight loss and gain, reduced self esteem, eating disorders and weight discrimination,” says Aphramor.

The authors suggest that focusing on health instead of body weight does occasionally lead to a drop on the scale, but that health benefits are measurable even if no weight loss is achieved. They cite improvements in blood pressure, lipid profiles, self-esteem, body images and other markers of well-being. However there was no mention of diseases that are not tied to metabolism and cardiovascular health. Breast cancer, for example, is known to correlate with body size and is thought to be caused by the extra estrogen produced in fat cells.

It makes intuitive sense that shifting focus toward healthy habits and away from body size would be a more effective strategy for long-term health, but fat loss (rather than weight loss) may still be a worthwhile target.

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It probably goes without saying — the dentist’s chair isn’t the most popular place to visit. But going to the dentist may one day be a very different experience. Researchers at the University of California San Francisco are developing new technology that may make a dentist’s drill less common.

Inside one of the treatment rooms at the UCSF School of Dentistry, Dr. Peter Rechmann is holding a small tool that could be a very big leap forward in dentistry — a laser. Unlike that familiar drill we love to hate, a laser drills into a tooth without making contact.

Listen to the QUEST radio story Visiting the Dentist Chair of the Future.

“So you don’t feel vibration. Yes, you hear the sound, you hear the tck tck tck, but that’s it,” says Rechmann. That makes a big difference, especially when Rechmann is working with younger patients. “Kids typically fear things more than adults. And they don’t care, they like it. Sometimes they say, ‘Oh, that was interesting’.”

Lasers have been used in dentistry for about a decade, but mostly on soft tissues like gums. Rechmann says laser drills are becoming more common now that the cost is coming down. And he expects lasers to soon play an even bigger role by actually helping to prevent cavities.

Rechmann holds a pulled tooth and fires short laser pulses at a small area on the outside. “The temperature on the enameled surface gets heated up to between 400 and 1000 degrees Celsius. It sounds terrible but it’s not. It’s really just the outer surface,” he says.

The extreme temperature slightly alters the make up of the outer tooth enamel which, Rechmann says, makes it more resistant to tooth decay. They’re now testing the treatment in clinical trials and it could be available in one to three years.

“If you treat this once, OK, you should still keep on brushing your teeth, but it’s really strongly protecting your teeth,” says Rechmann.

Of course, what our teeth really need protection from are our own bacteria. They’re specially adapted to live in our mouth, which, with all the food we chew, is a pretty nice place to call home.

“It’s a very nice place. It’s nice and warm and comfortable,” says John Featherstone, Dean of the UCSF School of Dentistry.

“Bacteria produce acid – that’s their major waste product. And that acid dissolves the enamel in the teeth.” Featherstone says in the past, dentistry has been focused on cleaning up the damage done by these bacteria. Now, he also sees the field moving towards prevention.

“If we can diagnose as we can now early on, what it tells us is that there’s disease process going on and we have to halt the disease process,” says Featherstone.

But given our teeth brushing habits – or lack thereof – Featherstone says there will probably always be a need to fill cavities. But what if cavities could fill themselves?

Self-Filling Cavities

Stefan Habelitz is standing in front of a refrigerator that holds 20,000 pulled teeth, collected from local dental clinics. Habelitz is a material scientist. He studies the structure of teeth.

“It’s amazing, a really amazing structure. For an engineer, it’s a real feast,” says Habelitz.

Tooth enamel is the hardest substance in our body. It’s designed to break apart foods like seeds or hard candy. “But if it can’t, it will release stress by forming fractures, by forming cracks,” Habelitz says.

Those tiny cracks are actually good — they’re part of the tooth’s design. They prevent it from being broken by one big crack. The problem with our teeth, Habelitz says, is that unlike our bones or skin, we can’t regrow tooth enamel. At least, not by ourselves.

“So let’s just drop these teeth in here.” Habelitz takes a few teeth with very large cavities and drops them into a beaker filled with a special solution. Tooth enamel is made of a mineral – so Habelitz says it’s not too difficult to remineralize or rebuild the enamel. That’s something the fluoride in toothpaste helps do.

“But once the bacteria makes it through the enamel, then it has been so far impossible to remineralize these legions,” says Habelitz.

That’s because deeper in the tooth in the material called dentin, minerals are mixed with organic structures, which are much harder to regrow. What Habelitz has in this beaker is a special compound that regrows the minerals and bonds them to the organic structures.

“So only when that link is established, the tissue that you build up again actually will be strong enough and stiff enough to support the pressure that you apply when you chew on your teeth,” he says.

One day, Habelitz says this process could be done right inside a patient’s mouth. The problem now is the process takes a long time — several weeks to fill a small cavity. “It should be an approach that needs to be done at least within a day, ideally within a few minutes.”

Habelitz is working to speed up the process, though it will be years before it’s available. But even if he and his colleagues can only regrow a small amount of a tooth, that’s part of a tooth that doesn’t have to be filled.

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Kids at schools with the School Lunch Initiative ate more vegetables, fruits and demonstrated greater knowledge of nutrition and health.

A recent report issued by scientists from the Atkins Center for Weight and Health at UC Berkeley examined the impact of the School Lunch Initiative (SLI) on the eating behaviors of children transitioning from elementary school to middle school. The SLI is sponsored by the Chez Panisse Foundation, founded in 1996 by Alice Waters.

The SLI is a system-wide program that includes cooking and gardening classes, integration of school lunch with food and nutrition curriculum, and improvements in campus food and dining services. The report examined the eating behavior of children at schools enriched with the SLI compared with children at schools with similar foods but without the program. The research followed fourth and fifth graders for three years to see the effects of the program during the transition from elementary school to middle school, since this is a time when healthy eating often deteriorates in children.

According to the report, SLI may have the potential to reverse the deterioration of healthy eating habits that children typically exhibit as they transition to adolescence. Compared with children in control schools, kids at schools with the SLI ate more vegetables, fruits and demonstrated greater knowledge of nutrition and health. Students in the SLI also showed greater preference for vegetables, particularly green leafy vegetables. Over the same period, children in schools without the SLI decreased their intake of fruits and vegetables both in and out of school. These trends were still apparent one year after completion of the SLI, when the students were in seventh grade.

The report is the first examination of the effectiveness of integrated school lunch programs on the healthy eating behaviors of children over an extended period. With the growing epidemic of childhood obesity, comprehensive school lunch programs have tremendous potential to improve the health and habits of developing children.

Though body mass index (BMI) improvements were not found in the current study, small sample size and measurement limitations may have made changes statistically undetectable. Since the trends observed in the eating habits of children in the SLI would predict a decreased risk for obesity, further studies are warranted to pursue the value of the program for improving health and body weight.

With the recent attention on the importance of school lunch programs (October 11-15 has been declared National School Lunch Week by the USDA), data on programs like SLI will be critical and could serve as a model for more broad government programs to improve nutrition at schools.

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