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New in Physiology (page 62 of 68)

Mar
08
2007

Cancer-Fighting Gene Guards Against Sun Damage

A gene that is known to play a key role in suppressing cancer also seems to protect against sun damage while promoting a golden tan.

The revelation could one day lead to better ways to prevent skin cancer, which roughly 1 million Americans develop each year.

"This finding provides us an opportunity to look at human populations with a varied risk of developing skin cancer and start to identify precisely what is regulating the risk of developing skin cancer rather than estimating," said senior study author Dr. David Fisher, director of the melanoma program at the Dana-Farber Cancer Institute at Harvard Medical School. "Right now, we're incredibly inaccurate in identifying risk and, therefore, in ameliorating risk."

The findings are published in the March 9 issue of Cell.

People who tan easily or have darker skin are much less likely to develop melanoma, the deadliest form of skin cancer.

"The tanning response is a protective response to injury, which can prevent further injury," explained Dr. Robin Ashinoff, medical director of Dermatologic, Mohs and Laser Surgery at Hackensack University Medical Center, in New Jersey. "On the one hand, the skin is the most common organ to be affected by cancer and, in principle, it ought to be preventable because we know the carcinogen which causes it, the sun."

Still, rates of skin cancer remain high.

"That's a terrible state of affairs in 2007," Fisher said. "We really want to understand the impact of ultraviolet radiation on the skin and what is the molecular cascade that is occurring downstream."

Six months ago, Fisher and his team published a paper documenting the fact that keratinocytes -- cells closer to the surface of the skin -- react to sun exposure. Previously, it had been thought that pigment-producing melanocytes played this role.

Once keratinocytes are exposed to rays from the sun, they produce melanocyte-stimulating hormone (MSH), a growth factor which binds to the pigment cells (melanocytes) and stimulates them to produce pigment.

Differences in the MSH receptor explain differences in ability to tan. Redheads, for example, have a variant which doesn't respond at all to MSH, explaining why the Nicole Kidmans of this world don't turn a tawny bronze.

Fisher and his colleagues still didn't know, however, what happened within keratinocytes to stimulate MSH production.

"We knew that ultraviolet radiation causes MSH to be induced," Fisher said. "How is the ultraviolet radiation doing that? What is perceiving the radiation and translating that signaling into making more MSH?"

The key happens to be the tumor-suppressor gene known as p53, which is induced in almost every keratinocyte of human skin samples within an hour of being exposed to the sun's ultraviolet rays. "That activity is completely regulated by this protein," Fisher said.

The finding is biologically plausible, experts said.

"It makes sense that most skin cancers and cancers, for that matter, have mutations in the p53 because it functions to protect us. It basically causes abnormal cells to be killed or die, and regulates all sorts of pathways that protect us," Ashinoff said. "It's not surprising that something that would protect us would also stimulate mechanisms in the skin known for protecting us."

"Knowing this, we can now identify exactly where we would like to interfere with the risk," Fisher added. "Knowing that p53 is part of this process allows us to potentially identify drugs that might be able to restore this response at different steps, depending on where the person might need it, where their block is."

HealthDay News, March 8, 2007 By Amanda Gardner

Feb
27
2007

Poorly Executed Cosmetic Procedures Can Leave Lasting Damage

A visit to a skin treatment clinic in a Florida suburban mall in late 2004 changed 52-year-old Jordan Miles' life forever.

She had responded to an ad from the clinic that promised help for her teenage son's acne. He didn't get the treatment, but Miles made an appointment for herself for laser treatments to remove sunspots on her arms, back and chest.

Two women ended up performing the procedure -- neither, Miles later found out, had the necessary training.

"They started with the laser on my chest, and when they got to my back, they decided the sunspots were worse, and so they upped the laser, further intensifying the procedure," Miles recalled.

The outpatient procedure left Miles, a mental health counselor, in such excruciating pain that she vomited on her way home. Getting no helpful response from the clinic, she consulted a dermatologist, who confirmed that she was covered in red, stripe-like second- and third-degree burns that would leave lasting scars.

The redness subsided, but each burn drained the pigment from her skin, leaving Miles open to further skin problems should she ever expose the affected areas to the sun.

"I now have what looks like zebra stripes everywhere," Miles said. "I'm restricted from a lot of activities and types of clothing. It's terrible."

Miles' experience is hardly unique. In the past few years, reports of fraudulent or shoddy cosmetic and plastic surgery procedures have grabbed headlines:

  • In 2003, New York City financial analyst Maria Cruz died after a fatal reaction to lidocaine, delivered by Dean Faiello, a 46-year-old from Newark, N.J., who had been posing as a cosmetic surgeon. Faiello fled to Costa Rica but was apprehended by U.S. authorities in 2006 and is now in prison.
  • In 2004, four people in Florida became paralyzed after Bach McComb, an osteopath with a suspended license, administered lab-strength botulism toxin -- not the much weaker Botox -- to himself, his girlfriend and two others. McComb was later sent to prison for three years.
  • In 2005, a 46-year-old California woman died of multiple organ failure after receiving a buttock injection of what had been billed as a "French polymer" but was actually cooking oil. The beautician who delivered the shot, 39-year-old Martha Mata Vasquez, was sentenced to 15 years in prison in January.

It's tough to tell how often these types of dangerous procedures are being performed in the United States, experts said.

"I think that, especially in big cities, it's more common than you think, because I see lots of patients with problems who have been treated in hotel rooms, for example," said Dr. Rhoda Narins, past president of the American Society for Dermatologic Surgery (ASDS) and a clinical professor of dermatology at New York University Medical Center.

"Sometimes, when I ask patient what it is that they have had, they really have no idea," she said. In many cases, procedures are performed in non-medical settings -- hotel rooms, private homes, beauty clinics and spas, Narins said. "I've seen several patients who had spa treatments and got comfortable there, and then they were offered non-medical-grade silicone. They ended up having horrendous reactions."

Dr. John W. Canady, vice president of the American Society of Plastic Surgeons (ASPS), said that the underground nature of these sub-par procedures makes them especially hard to track.

He and Narins said consumers should watch out for the following "red flags" when seeking out cosmetic injections or surgeries:

  • Check for credentials. It's not enough that your "doctor" is wearing a white lab coat and has a certificate on the wall. A number of organizations -- the ASDS, the ASPS, the American Board of Plastic Surgery and state medical boards -- have online resources that people can check to verify credentials and experience.
  • Be wary of cheap deals. "If a procedure has an unbelievable price that nobody else is offering, then you really have to slow down and examine why it's so cheap -- why is it so out of line with the rest of the market?" said Canady, who is also professor of plastic surgery at the University of Iowa.
  • Look for nearby medical support. Even procedures conducted by the best-qualified staff can go awry, so make sure your practitioner has equipment and qualified personnel on hand to deal with allergic reactions, clotting and other events. Most reputable clinics will have hospital affiliations. "As a patient, you want to know what things are available if things don't go right," Canady said.

Most of all, the experts said, ask questions.

"It's important to be a responsible consumer, to do your homework, to not be afraid to ask the tough questions," Canady said. "If you ask people legitimate questions in a non-offensive way, and they get angry or hostile with you, then you need to go find somebody else."

Narins agreed that an educated, proactive consumer is the best defense against fraud and abuse in her industry.

"People shouldn't take chances with their health. When you inject something into your body, this is not the same as getting a massage," she said. "This is something that can seriously affect you, and for a long time."

That's a lesson Miles said she learned the hard way, but she's hopeful that her story can at least help others. The clinic she received her laser treatment from has since closed down, and Florida state law was recently toughened to mandate that all laser procedures be done under a doctor's supervision.

But Miles said her scars are a daily reminder that patients remain vulnerable.

"Make no assumptions, and don't be afraid to ask questions," she advised. "The mistake I made was that I never asked these women if they were a nurse practitioner, or if they had any experience doing this before, or how many times they had done it before. All of those were major mistakes."

HealthDay News, 2/26/2007, By E.J. Mundell

Feb
22
2007

Spearmint Tea May Help Women With Hirsuitism

Drinking two cups of spearmint tea a day might help treat women with an unsightly condition that causes them to grow excess hair on their face, breasts and stomach, Turkish researchers report.

The tea works by lowering the levels of circulating male hormones in these women, the scientists claim in the current online issue of Phytotherapy Research.

The authors called the findings preliminary.

"There are no recommendations for patients and physicians yet," said Mehmet Numan Tamer, co-author of the study and a professor of endocrinology and metabolism at Suleyman Demirel University in Isparta, Turkey. "This is the first clinical study about the spearmint tea, but further studies are needed to give the practical recommendations to patients."

But other experts feel the findings are far-fetched.

"This is absurd," said Khursheed Navder, an associate professor of nutrition and food science at Hunter College in New York City. "I completely think it is very preliminary, and you need major randomized trials. It's nothing to get thrilled about."

Hirsutism is a condition that can occur in both men and women, but, for obvious reasons, it is more of a cosmetic concern in women. The hair growth is a result of unnaturally high levels of androgens such as testoserone.

According to Tamer, standard therapy includes oral contraceptives to suppress androgens or drugs such as spironolactone, which prevents the body responding to androgens.

Spearmint, which grows naturally near Isparta, has been widely used for indigestion, nausea and vomiting, as well as for the common cold, cough, sinusitis, fever and bronchitis.

"Spearmint has been used as an herb for a long time now," confirmed Navder. "These are all folk remedies."

The Turkish researchers thought that spearmint might be linked with reports of diminished libido in townsmen (presumably because of its effects on androgen levels). In one previous rat study, spearmint reduced testosterone levels.

"Previously, we investigated the effects of [peppermint] and [spearmint] herbal teas on testicular function in an experimental rat model and found that testosterone levels were decreased," Tamer said. "Because we found the anti-androgenic effects of spearmint, we decided to observe the effect of this herbal tea on the androgen levels in hirsute women."

For this study, 21 women with hirsutism drank two cups of herbal spearmint tea for five days at a certain time in their menstrual cycle.

All women showed a decrease in free testosterone (circulating hormone not bound to other molecules) and an increase in several different "female" hormones, including follicle-stimulating hormone and estrogen.

There was no significant decrease in total testosterone levels; it was unclear if there was any change in amount of excess hair growth.

"The next step is to show the effect of spearmint tea on hirsutism scores of the women in a treatment period," Tamer said.

Although the amounts of spearmint used in this study are not generally toxic, the herb can be harmful if taken in larger amounts

Feb
14
2007

New Drug Helps Ease Psoriasis

Many patients with moderate to severe chronic psoriasis showed significant improvement after treatment with Humira (adalimumab), according to a study presented at the recent annual meeting of the American Academy of Dermatology in Washington, D.C.

The REVEAL (Randomized Controlled EValuation of Adalimumab Every Other Week Dosing in Moderate to Severe Psoriasis TriAL) included 1,200 patients. After 16 weeks, 71 percent of the patients who took the drug showed a 75 percent improvement in skin clearance, compared to 6.5 percent of patients who received a placebo.

The study also found that patients who took the drug continuously were much less likely to experience a worsening of their psoriasis symptoms.

Upper respiratory tract infection, headache and nasopharyngitis were the most common side effects reported by patients in the study.

The REVEAL results will be submitted by drug maker Abbott in its applications to have Humira approved for treatment of psoriasis in the United States and Europe.

Psoriasis is an autoimmune disease that causes raised, inflamed, scaly, red skin lesions that can crack and bleed. There is no cure for psoriasis, which affects about 125 million people worldwide. Of those, about 25 percent have moderate to severe psoriasis. The disease can occur at any age but typically appears between the ages of 15 and 35.

HealthDay News, February 13, 2007

Feb
07
2007

Hundreds of Bacteria Species Discovered on Human Skin

Human skin is crawling with bacteria, say U.S. researchers who identified more than 200 species -- 8 percent of which were previously unknown -- on samples collected from the forearms of six people.

The New York Medical School team used genetic analysis to detect the types of bacteria present on the volunteers' skin, BBC News reported.

An initial analysis detected 182 species of bacteria. Another test was conducted eight to 10 months later to see if there had been any changes. That second analysis revealed 65 more kinds of bacteria.

About half the species were already known to be common skin dwellers, but 8 percent had not been previously described in scientific literature. The researchers also found that about 75 percent of the bacteria species were unique to individuals, which suggests the skin is "highly diversified," BBC News reported.

The findings were published online in the journal Proceedings of the National Academy of Sciences.

"Over the years maybe about 50 different organisms have been found in human skin but we knew there were more organisms present" that couldn't be detected, study leader Martin Blaser, professor of microbiology, said in a prepared statement.

"We have now gone up five-fold from what's been known before," he said.

Experts say that bacteria plays an important role in keeping skin healthy, BBC News reported.

HealthDay News, February 6, 2007

Feb
05
2007

Genital Skin Cancer More Deadly for Females

Women are three times more likely than men to die of genital nonmelanoma skin cancer, new U.S. research shows.

Genital nonmelanoma skin cancer can be caused by sexually transmitted human papillomavirus (HPV), which is also associated with cervical cancer.

In this study, researchers found that almost 30,000 people -- 22,000 women and 8,000 men -- died of genital nonmelanoma skin cancers in the United States from 1969 to 2000.

The older a person is, the greater their risk of genital nonmelanoma skin cancer (NMSC). The findings were scheduled for presentation Sunday at the annual meeting of the American Academy of Dermatology, in Washington, D.C.

"As dermatologists, we expect to see skin cancers induced by ultraviolet light, because sunlight is one of the primary risk factors for the disease," researcher Dr. Martin A. Weinstock, professor of dermatology and community health at Brown University in Providence, R.I., said in a prepared statement.

"But some of the most dangerous types of skin cancers are those that are not sun-induced, such as skin cancers that occur on genital skin -- a place that is not exposed to intense sun and is not routinely examined by dermatologists. That's why there needs to be an increased awareness of this issue, so patients and physicians can be better prepared to detect these cancers early before they become fatal," said Weinstock, who is also chief dermatologist at Veterans Affairs Medical Center in Providence.

Because they're not always readily visible and may not cause any noticeable symptoms, genital skin cancers can be difficult to diagnose.

"The number of deaths attributed to genital NMSCs was higher than expected, and we believe HPV was a major cause of these cancers," Weinstock said.

"The availability of the new HPV vaccine offers the potential for a substantial reduction in the development of these skin cancers for future generations," he noted.

In addition, since "HPV is a sexually transmitted disease, both men and women can practice preventive measures that could lead to a decline in mortality rates from genital NMSCs and heed the warning signs of the disease, including new growths or sores that don't heal, to detect it early."

HealthDay News, Monday, February 5, 2007

Feb
02
2007

70 Potential New Psoriasis Treatments Being Investigated

Psoriasis Cure Now, a nonprofit patient advocacy group, today reported that biotech and pharmaceutical companies are investigating a record 70 potential new treatments for psoriasis and psoriatic arthritis. The data, culled from published reports and clinical trial recruitment Web sites, shows continued, strong business interest in the psoriasis market.  A New York Times article last week called into question the profitability of the psoriasis sector, lighting up psoriasis message boards with concerns that the psoriasis drug pipeline could dry up. The full (and free) report of psoriasis treatments under clinical development is available on the Psoriasis Cure Now Web site: www.psoriasis-cure-now.org/hope.php.

Jan
31
2007

FDA Approves YAZ Birth Control Pill Can to Treat Acne

The U.S. Food and Drug Administration has ruled that the oral contraceptive YAZ can also be used by women to control moderate acne, the Associated Press reported..

The decision means that YAZ, made by Bayer Schering Pharma AG, is the first oral contraceptive to be approved by the FDA for three distinct uses, the drug maker said in a statement released Monday.

Along with birth control and acne treatment, YAZ is also approved in the United States to treat the physical and emotional symptoms of premenstrual dysphoric disorder, the AP reported.

HealthDay News, January 30, 2007

Jan
30
2007

A Little Sun Might Shield Against Skin Cancer

It's a puzzle to scientists, but a new study suggests that the main cause of deadly skin cancer -- sunlight -- might also help protect against the disease.

The key could lie in the amount of ultraviolet B (UVB) light the skin absorbs -- enough to stimulate a healthy, vitamin D-linked immune response in the skin but not so much that it boosts skin cancer risk.

"I do think that a little bit of sunlight is good for people, but I think that one of the problems that the American Cancer Society and dermatologists have is, how do you define what a little bit is?" said skin cancer researcher Marianne Berwick, chief of epidemiology at the University of New Mexico's Cancer Research and Treatment Center. "How do you tell people that it's OK to have a little bit of sunlight but not too much?"

In 2005, Berwick's team published a controversial study that found that melanoma patients with higher levels of daily sun exposure actually had better survival than patients who spent less time in the sun.

"I've been searching for an explanation for that ever since," she said.

Now, findings from a group led by immunologists at Stanford University may provide an answer. The study, led by professor of pathology Eugene Butcher, is expected to be published in the March issue of Nature Immunology.

In its study, the Stanford team worked with cells in the lab and discovered a biochemical chain of events that appears to link sunlight exposure to the skin's own immune defenses.

The researchers started from the notion that an inactive precursor of vitamin D, called vitamin D3, "is generated in the skin in response to sun exposure." That's been known for years. Specifically, a short-wavelength form of UV light, called UVB, is responsible for D3 generation.

D3 is inert and powerless, however. Through contact with various enzymes in the liver and kidneys, the body turns D3 into an active compound called 1,25(OH)2D3.

And that's where the immune-system connection kicks in, the Stanford authors said.

In their experiments, they found that the new compound "signaled (immune) T-cells," pushing them to migrate back to specific sites in the skin's epidermis. Once there, these powerful immune system agents stand on guard against infection and even cancer, the researchers said.

"So, the same wavelengths of sunlight that are most potent in inducing skin cancer -- UVB -- are also the wavelengths that produce this vitamin D precursor, D3," said Dr. Martin Weinstock, chairman of the skin cancer advisory group at the American Cancer Society. And it's D3 that starts the whole chain of events rolling.

Weinstock stressed that the Stanford study is far from conclusive, however, and should not be seen as an excuse to bake in the sun.

"We know that the sun is the major avoidable cause of skin cancer," he said. "This study is interesting and points to a productive area of research, both to confirm this in other settings and to flush out the implications of the finding. But does it really relate to skin cancers in real live people? We don't know."

"So, avoiding intense sun, protecting yourself when you're out in intense sun -- that's still our [cancer society] recommendation, and this is not going to change that," said Weinstock, who is also professor of dermatology and community health at Brown University.

Kathleen Egan, a professor of epidemiology at the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., agreed that the study findings are "tantalizing" but need further study.

Especially since the release of Berwick's melanoma study, "there's been an awful lot of questions about how -- or if -- vitamin D has a part to play in potentially offering some [cancer] protection under some circumstances," she said. "But it's very difficult to tease out, because the main human source of vitamin D is, in fact, sunlight exposure, which is also the most important risk factor for melanoma."

Nutritionists have known for decades that sunlight stimulates vitamin D production in the skin. In fact, this natural process is the body's major source of the nutrient. A proper amount of vitamin D is crucial to bone health, "and there's also a bunch of evidence that vitamin D may have a role in preventing colon cancer, although there's still some controversy about that," Weinstock said.

So, how much sunlight is enough to get the ideal amount of vitamin D?

Katharine Tallmadge, a Washington, D.C., dietitian and a spokeswoman for the American Dietetic Association, suggests that most people can probably get the U.S. Department of Agriculture's recommended 400 daily IUs of vitamin D by spending a half-hour to an hour outside per day.

Egan agreed. She said it's not difficult for people to soak up the sun's goodness without boosting their cancer risk. In response to even a moderate amount of sunlight, "the skin actually creates an amazing amount of vitamin D," Egan said. "It doesn't take much exposure to make enough of the vitamin D that's certainly needed to preserve bone health, for example."

By E. J. Mundell, HealthDay News, January 29, 2007

Jan
17
2007

Partners Can Help with Skin Self-exam

Two are better than one when it comes to performing a skin exam for melanoma and spotting it at the earliest, most treatable stage, a new study shows.

Men and women at high risk of developing melanoma who underwent skin self exam training with their live-in partner were more likely to perform the exams than those who trained solo, Dr. June K. Robinson of Northwestern University Feinberg School of Medicine in Chicago and colleagues found.

People trained to perform a skin self exam also seek treatment at an earlier stage of melanoma and are less likely to die from it, Robinson and her team note in the Archives of Dermatology. They hypothesized that training couples in skin self exams would be even more effective than training individuals because couples may encourage each other to do the exams and help each other another to perform them.

To investigate, Robinson's group randomly assigned 130 people to undergo a 10-minute training on skin self exams alone or with their live-in partner.

Four months after the training, 45 of the 65 people who underwent solo training had not examined their skin, compared with 23 of the 65 who trained with their partner. Of the paired learners, 19 checked their skin at least once and 13 checked it several times, compared with 9 and 4 of the solo learners, respectively.

The men and women who learned in pairs also were more likely to perceive the exams as important and to feel confident in their ability to perform the exams, the researchers found.

The study "affirms the role of partners in health care and extends it to promoting health behaviors," the researchers conclude.

Reuters Health, January 16, 2007