New England Public Radio

Giving the human papillomavirus vaccine to teenage girls doesn’t increase the likelihook that they will be sexually active, according to a new study.

That may help put parents’ at ease; the notion of vaccinating 11- and 12-year-old girls for a sexually transmitted virus has made some uncomfortable, and is one reason why only a little more than half of teenage girls have had the vaccine.

When it comes to sex and daughters, evidence doesn’t trump emotion. Julie Stewart is one of those parents. She told NPR’s Richard Knox last fall that it seems premature to be giving her preteen daughter a vaccine to protect against cervical cancer, which can be caused by HPV.

“I realize it’s probably more about my squeamishness with the thought of her becoming sexually active than the vaccination itself,” Stewart says. “It’s not the science. I think it’s my own issues around her developing sexually.”

Researchers hoping this new study will help parents like her come to grips with their squeamishness.

Rather than ask girls to report whether they were sexually active, the study authors looked at medical records from teenage girls who went to the doctor at Kaiser Permanente clinics in Georgia. They identified the ones who had become pregnant, had contracted a common sexually transmitted disease, or had asked for counseling about using contraceptives.

Then they looked to see which ones had had at least one HPV shot when they were 11 or 12. (The full regimen is three shots; one study in 2010 found that only 30 percent of eligible women and girls get all three shots.)

Of the 1,398 girls in the Kaiser study, the ones who had the HPV vaccine were no more likely to have had sexually related health issues than were the ones who hadn’t. In both groups, only about 10 percent had medical visits related to sexual activity in the three years after getting the vaccine.

“You never know exactly at what age girls will become sexually active,” says Robert Bednarczyk, a clinical investigator with the Kaiser Permanente Center for Health Research Southeast and an epidemiologist with the Rollins School of Public Health at Emory University, who authored the study. “By providing the vaccine earlier, it gives protection into adolescence and early adulthood.”

But he acknowledges that parents’ concerns about daughters and sexual activity remain a barrier to widespread adoption of the HPV vaccine, along with concerns about vaccine safety. “It is trailing behind other adolescent vaccines,” Bednarczyk told Shots.

This is the first study to look at the question of HPV vaccine and sexual activity that didn’t rely on girls to report whether they were sexually active. It was published in the journal Pediatrics.

Earlier this year the American Academy of Pediatrics recommended that teenage boys get the HPV vaccine, too, but that decision hasn’t sparked nearly as much worry as has vaccinating girls.

A different bit of data may be the most reassuring: The number of teenage girls who are sexually active has been declining steadily. Now less than one-third of 15- to 17-year-old girls say they’ve had sex, compared to 39 percent in 1995, according to surveys from the Centers for Disease Control and Prevention.

The CDC and the pediatricians say that vaccinating well before teenagers become sexually active is the best way to ensure that they will be protected against HPV infection as teenagers and young adults.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

Even extreme stress doesn’t have to get you down.

That’s the message from brain scientists studying the relationship between stress and problems such as depression, anxiety and post traumatic stress disorder, or PTSD.

Researchers at the Society for Neuroscience meeting in New Orleans presented studies showing how stress caused by everything from battlefield trauma to bullying can alter brain circuitry in ways that have long-term effects on mental health.

Current treatments for these problems often come up short. But the scientists say new insights about how stress affects the brain suggest several ways the process could be interrupted or reversed.

“That’s the holy grail and we’re moving in that direction,” says Dipesh Chaudhury of Mt. Sinai School of Medicine in New York.

Chaudhury says one way traumatic events appear to cause depression is by inhibiting the brain’s so-called reward system, which normally cause pleasurable feelings when we spend time with friends or eat a favorite food. Soldiers with PTSD and people with major depression often report that these things no longer give them pleasure.

Mice respond in a similar way to traumatic events, Chaudhury says. And his research shows that this response can be prevented by reducing the activity of certain brain cells involved in the reward system.

The trick now is to find a drug that produces the same effect in people, Chaudhury says.

Another way stress affects mental health is by releasing chemicals that impair the function of the prefrontal cortex, which is where higher level thought takes place, says Amy Arnsten, a neurobiologist at Yale. When that happens, she says, “We switch from being thoughtful creatures to being reactive creatures.”

That can lead to anxiety and PTSD, Arnsten says. But studies suggest at least two drugs seem to help the prefrontal cortex work better.

One of these is the blood pressure drug Prazosin, which has been used experimentally to treat both soldiers and civilians with PTSD. Another is a drug called guanfacine, which seems to help drug addicts who relapse under stress.

The anesthetic and anti-depressant drug ketamine also seems to help with PTSD, says Neil Fournier, a researcher at Yale University School of Medicine.

Studies in mice show that ketamine helps them forget fearful events, probably because it causes the formation of new nerve connections in the brain. And there is preliminary evidence that wounded soldiers who got ketamine to relieve pain were less likely to develop PTSD.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

You’d think that someone who is a science correspondent and is as allergic to poison ivy as I am would have heard of urushiol, but no. I didn’t recognize the word when I saw it a week or so ago. Now, thanks to my new beat (Joe’s Big Idea), I’m allowed to dig a little deeper into stories, and what I learned about urushiol is pretty amazing.

It all started with a press release I received from the American Chemical Society highlighting an article in the Journal of Organic Chemistry.

Urushiol is the oily sap on poison ivy leaves that causes all the problems. In the paper, Rebecca Braslau and her colleagues at the University of California, Santa Cruz, describe a nontoxic spray that will fluoresce in the presence of urushiol.

Braslau has gotten that horrible poison ivy rash more times than she’d care to remember. She knows how to avoid the plant herself, but she has a problem. “My husband’s a geologist. He tramps around in the Santa Cruz mountains,” she tells Shots. Her husband is one of those lucky people who isn’t allergic to the oil in poison ivy.

“When we first got together he wasn’t very careful about it, and so he would get it on his arm and he wouldn’t even know it,” Braslau says. And then he’d put his arm around her and she’d break out. So Braslau got to thinking: “There’s got to be some way to deal with this, and I just had this eureka moment because I thought about it for a couple years.”

The eureka moment involved a class of chemicals known as nitroxides. Braslau was able to develop a nitroxide-based solution that would react only with the oil in poison ivy. By adding a fluorescent dye that would show up only when the reaction occurred, she could spray her nitroxide solution on a surface, and if the poison ivy oil were there, the surface would light up.

She says until there is thorough safety testing, it’s probably best to use the spray on inert things like shoes or backpacks to see if the oil is there.

“Ultimately I would love to be able to spray it on my arm, or my husband or my dog, and find out where this stuff is,” she says.

The compound Braslau describes in the article is just a proof of concept. She says she needs to find a better dye, maybe even one that will light up without having to shine a fluorescent light on it. She’s got a patent and would be happy to hear from potential investors.

So, OK, Braslau’s spray lets you know you’ve been exposed to urushiol. Then what, I asked her?

“TecNu,” she replied.

TecNu is a water-free cleanser. There are other soaps that work getting the oil off — for example, that stuff called Goop car mechanics use to degrease their hands, Braslau says, and some dish-washing detergents. But she relies on TecNu.

Mark Christensen, a chemist at Oregon State University, works on TecNu for its manufacturer, Tec Labs of Albany, Ore.

I asked him why TecNu was so good at removing poison ivy oil from someone’s skin, and he said it was because it contains a benzene ring which has ortho hydroxyls, and “then para to that off of that benzene ring is a long alkyl unsaturated chain, 15 to 18 carbons.”

Not quite the simple explanation I was hoping for. After he explained it a bit more, the idea seems to be the chemicals in TecNu can mix with poison ivy oil so you can wash it off your skin.

One other interesting thing about urushiol: It’s harvested from the Japanese lacquer tree and prized as a lacquer for artwork. Antoine Wilmering is an expert in urushi lacquerware, as it is known at the Getty Foundation in Los Angeles. He says you apply multiple layers of the lacquer with a brush, cure and polish each layer, “and then you get these really beautiful shining surfaces.”

The good news is if you properly cure the lacquer, it not only hardens but it also loses its allergenic properties. But an object covered with improperly cured urushiol lacquer can still cause a rash.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

Acne, the scourge of many an adolescent life, is getting harder to treat, but 80 percent of teenagers have some form of acne.

Conventional treatment includes topical and oral antibiotics. Studies are now finding the bacteria that cause acne are increasingly resistant to antibiotic treatment. Alternatively, there are effective laser treatments. But these are costly and typically not covered by insurance.

Now, researchers are scrambling to come up with new treatments for acne. One promising possibility involves harnessing a harmless virus living on skin that naturally seeks out and kills the bacteria that cause pimples.

‘People Always Notice’

It’s every teenager’s nightmare: big, blistery red bumps on their face.

“That’s what people notice first about you, so no matter how great of a person you are, no matter how pretty your eyes are, how nice your smile is, people always notice the blemishes on your face,” says Rohini Bagrodia, a really pretty 22-year-old with beautiful eyes, a great smile — and a history of battling acne.

In school, it meant avoiding the spotlight. “I would always shy away from those opportunities that would bring all the focus on me,” Bagrodia says. She wouldn’t take part in class discussions. She wouldn’t raise her hand. And it’s all because of a tiny bacteria that lives on the skin.

UCLA dermatologist Dr. Jenny Kim says many people don’t realize it’s bacteria that cause acne. “Some people say your face is dirty, you need to clean it more, scrub more, don’t eat chocolate, things like that. But really, it’s caused by bacteria and the oil inside the pore allow the bacteria to overpopulate,” Kim says.

For most teenagers with mild acne, over-the-counter products containing peroxide or salicylic acid are enough to clear up the acne. But, lots of teenagers end up in the doctor’s office and getting antibiotics. This was the hardest thing for Bagrodia: No matter how much she followed doctors’ orders, diligently cleaning her face and using antibiotic cream, nothing worked.

Antibiotic-Resistant Bacteria

Dermatologist Elizabeth Martin is in private practice in Birmingham, Ala., and is a fellow with the American Academy of Dermatology. She says this bacteria, like many others, is mutating quickly and becoming resistant to antibiotics.

“Over the years, we have seen an increase in this antibiotic-resistant bacterium, both in the U.S. and also worldwide,” Martin says. She points to studies that show a tripling of drug-resistant acne bacteria over the past few decades.

This means doctors can no longer rely on antibiotics alone. Most doctors now use a combination of low-dose antibiotics along with benzoyl peroxide, which also kills acne-causing bacteria.

As Martin says, benzoyl peroxide “works to decrease bacteria through a different mechanism than antibiotics, and it helps to prevent development of resistant bacteria. When we combine benzoyl peroxide along with an antibiotic, patients tend to have better clearance of their acne than when we use antibiotics alone.”

Other Treatment Options

Retinoids, vitamin A derivatives, can also be used early on to treat acne. Typically creams, they work by unclogging pores before they become large, inflamed bumps.

A stronger form, called Accutane, is used for severe acne. It’s a highly effective pill, but it can cause serious side effects, including depression and birth defects. So the government regulates its use.

Intensely focused light and lasers can also help fight acne when other treatments fail. Kim is also a researcher at UCLA. In the room dedicated to light and laser therapy, Kim points out what appears to be a half cylinder with stacks of oblong light bulbs.

“Patients with acne can go right under blue light, and they sit there for about 15-20 minutes, and acne often improves after several treatments,” Kim says.

It’s not known exactly how light therapy works to fight acne, but Kim says studies indicate it destroys the bacteria. “Probably physically without giving it time to mutate; and the other thing — the light treatment can improve the inflammation that the bacteria causes in acne,” she says.

But laser and light therapy doesn’t work for everyone. It’s expensive and typically not covered by insurance. So Kim and colleagues at the University of Pittsburgh are also looking into an entirely new way to fight acne: taking a harmless virus that lives on the skin and programming it to become a bacteria killer.

“The virus is going to go and kill the bacteria that causes acne. It’s just going to break it apart and burst its membrane so there’s no time for the bacteria to mutate,” she says. It’s sort of a surprise attack.

The approach is a promising way to get rid of acne without using antibiotics. If further lab studies prove successful, researchers will begin testing on people to see if viral therapy is both safe and effective in fighting acne.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

It’s hardly surprising that Thursday night’s vice presidential debate in Danville, Ky., would feature a spirited debate about Medicare. GOP vice presidential nominee Paul Ryan is the author of a controversial Medicare proposal that Democrats have been campaigning against for more than a year now.

But fact checkers have raised some flags about some of the claims the candidates made.

For example, here’s Joe Biden, delivering the Democrats’ favorite attack line against the GOP plan: “Their ideas are old and their ideas are bad, and they eliminate the guarantee of Medicare.”

This is actually largely true. What Biden was using here is shorthand for the way Medicare is structured today, which is a guaranteed set of benefits, which continues to be guaranteed no matter how much they cost. What Republican challenger Mitt Romney and Rep. Ryan are talking about is giving Medicare recipients a fixed amount of money instead, which might or might not be enough to pay for the benefits Medicare currently provides. So in that sense, the Republican plan does eliminate Medicare’s current guarantee, although Medicare as a program would continue to exist.

Ryan tried to insist that his Medicare plan is bipartisan. “It’s a plan I put together with a prominent Democrat senator from Oregon,” he said.

But while Sen. Ron Wyden, D-Ore., did produce a policy paper with Ryan last December, it has not yet been turned into legislation that he can support. In fact, Wyden voted against the version of Ryan’s House budget that came to the Senate floor this spring, and took Romney to task when he named Wyden as a partner in the Medicare effort.

Wyden was quick to respond again when Ryan tried to make him an ally during the debate. “The Vice President is right,” Wyden wrote in a post on his Facebook page. “Romney Ryan moved the goal post on Medicare and I strongly oppose their plan because I believe it hurts seniors.”

Ryan didn’t confine his health care claims to Medicare. He also struck out against the 2010 Affordable Care Act. “Look at all the string of broken promises,” he said. “If you like your health care plan, you can keep it. Try telling that to the 20 million people who are projected to lose their health insurance if Obamacare goes through.”

This number, however, is one Republicans have been taking way out of context. It’s the number the Congressional Budget Office says could no longer have employer provided health insurance when the law is fully phased in, under the worst-case scenario. The more likely number is closer to three to five million, CBO says.

Now a lot of those people are likely to get insurance other ways, probably ways they will prefer; this includes people who are working solely to keep insurance; they may want to start their own business, or they may want to retire. Overall, the CBO says the law will boost the number of people with health insurance by about 30 million.

Not all the misstatements were made by Ryan, however. For example, there was this comment from the vice president when Rep. Ryan complained about a panel that could potentially ration care: “You know, I heard that death panel argument from Sarah Palin. It seems every vice presidential debate I hear this kind of stuff about panels.”

Except that while Sarah Palin was indeed active in complaining about “death panels,” that didn’t start until the summer of 2009; nearly a year after her debate with Joe Biden.

Biden also at one point suggested that under the Rep. Ryan’s budget, “he will knock 19 million people off of Medicare.” If Ryan looked a bit surprised by that, it’s because the vice president likely meant to say Medicaid, not Medicare.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

Lately, we’ve been learning more and more about the teeming masses of bacteria inside our bodies – essentially trillions of tiny organisms that make us sick and keep us healthy.

Now two scientists at the University of Colorado have dared to ask what kinds of bacteria lives inside our mouths. And they’re finding some pretty surprising things in there.

Ken Krauter, a professor of microbiology, and Simone Stahringer, a graduate student, took oral bacteria samples from 45 sets of twins and sequenced the bacteria’s DNA. They thought that identical twins would have similar types of bacteria living in their mouths, because identical twins share the same genetic make-up.

They were wrong.

The identical twins’ bacteria was not any more similar than the bacteria living in the mouths of fraternal twins, who only share half of their genes. Furthermore, Krauter and Stahringer, whose findings were published this week in the journal Genome Research, found that when identical twins stop living together in the same house, their oral bacteria became a bit more distinct.

What this tells us, Krauter said, is that, unlike in other parts of the body, oral bacteria is determined by environment, not genes.

“[We thought] that the human genome or your immune system or the surfaces of your mouth would have a profound affect on which microbes would choose to live in your mouth,” Krauter said. “But that wasn’t really the case. The most abundant bugs that are living in your mouth are dependent on what you eat, who you kiss, how often you brush your teeth.”

At the same time, bacteria in the mouth is generally more homogenous than the bacteria in the gut, where there are communities of bacteria unique to individuals. Most of the bacteria in the human mouth can be grouped into eight basic types, Krauter says.

Those oral bacteria that fall outside of these eight types – the outliers, as he called them – may cause disease. But Krauter says if we can find a way to identify them, scientists could figure out ways to fight them.

But Krauter and Stahringer have a long way to go before they can take their work out of the lab and into the doctor’s office. Right now, they’re just trying to figure out exactly what is living in our mouths.

Figuring out how those they work for or against us will have to come later.

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.