Most Popular in:

Physiology

New in Physiology (page 71 of 73)

Sep
08
2006

Eczema Rates Stabilizing in U.K.

Rates of eczema and hay fever in the United Kingdom appear to have stabilized, after charting a steady rise over recent decades.

However, the study also found that rates of systemic allergic reactions -- including the severe condition known as anaphylaxis -- have surged in the past 20 years.

The researchers analyzed data gathered from numerous sources: national surveys, primary care doctors, prescription and hospital admission records, and death records.

Over the past three decades, diagnoses of allergic rhinitis and eczema in children have tripled, but there appears to have been a recent decrease in the prevalence of symptoms. Hospital admissions for eczema have stabilized since 1995, the researchers found, while admissions for allergic rhinitis have decreased to about 40 percent of their 1990 levels.

Between 1971 and 1991, the number of consultations with family doctors about hay fever increased by 260 percent and by 150 percent for eczema. However, these rates have stabilized in the past 10 years, the study said.

Hospital admissions for anaphylaxis have soared by 700 percent, for food allergy by 500 percent, and for the skin allergy urticaria by 100 percent.

Prescriptions for all types of allergies have increased since 1991.

The researchers said that some of the trends could be related to changes in medical practice and care but could also be explained by changes in the sources of allergic disease.

The study was published in the current issue of Thorax.

HealthDay News, September 7, 2006

Sep
06
2006

CTFA Requests Public Comments on Skin Absorption

The Cosmetic, Toiletry, and Fragrance Association (CTFA) is requesting public comments by September 25, 2006, on a new Safety Evaluation Guideline addressing the topic of Skin Absorption.

The guideline describes in vitro test methods for evaluating skin absorption.

The CTFA Safety Evaluation Guidelines provide manufacturers with guidance regarding the use of preclinical and clinical safety testing as a means to substantiate the safety of both ingredients and finished cosmetic products.  They are part of the CTFA Technical Guidelines series.

 Each Guideline undergoes an extensive development and review process by CTFA technical committees and staff, as well as public review by CTFA member companies, nonmember companies, federal government agencies, and scientific professional societies. 

An electronic copy of the draft guidelines is available from the CTFA Public Affairs Department by contacting Lisa Powers, (202) 446-0489 or email at powersl@ctfa.org.

Sep
05
2006

FDA Seeks Ban on OTC Skin Bleaching Products

The FDA is seeking to ban over-the-counter sales of skin bleaching drug products.

The FDA cites the possible risk of cancer and skin discoloration from hydroquinone typically found in these products.

However, those cancer studies were done on rats, not people.

"The actual risk to humans from use of hydroquinone has yet to be fully determined," the FDA states in its proposal, published in the U.S. government's Federal Register.

The type of skin discoloration noted by the FDA is called exogenous ochronosis, a darkening of the skin. The FDA cites research linking the condition to hydroquinone use.

The FDA isn't proposing a ban on prescription skin bleaching drug products. But all such products would need to submit a new drug application for the FDA's review.

Not all skin lighteners contain hydroquinone. The FDA knows of 200 products containing hydroquinone in strengths from 0.4% to 5%, about two-thirds of which "appear to be marketed as OTC [over-the-counter] drugs," says the FDA.

The FDA is taking comments on its proposal until Dec. 27.

Expert's Views

WebMD spoke with dermatologist Susan Taylor, MD, of Society Hill Dermatology in Philadelphia, and the Skin of Color Center in New York about the FDA's proposal.

"I feel that hydroquinones are safe and effective treatment for pigmentary disorders," Taylor says. "I feel comfortable recommending that my patients continue to use hydroquinones if they have a pigmentary disorder."

"I think the evidence is quite weak with the link between hydroquinones and cancer," Taylor tells WebMD.

"Data on rats and mice cannot necessarily be extrapolated to human data," she says.

"In Africa, people have used hyrdoquinones for long periods of time ... meaning years, 10, 20, 30, years ... and at high concentrations," Taylor says. "We've not seen a proliferation of various types of cancers reported from that population.

Exogenous ochronosis is rare in the U.S., Taylor notes.

"If you look at the case reports, it's probably less than 200," Taylor says. "So it's really not a significant problem here in the United States."

Millions of Users

Taylor points out that "many patients have disorders that are truly disfiguring and devastating. And these conditions can be improved significantly with hydroquinone products."

"It's important therapy and it's used by millions and millions of people," Taylor says.

She says hydroquinone products are primarily used to lighten dark areas of the skin due to conditions including injury, rashes, acne, and sun damage.

"So there are real problems and this is a real solution," Taylor says. She adds that filing new drug applications can cost millions of dollars.

"My concern is that we could lose prescription products that we have," Taylor says. "That would have major consequences, I think."

"It's safe, effective; it's the gold standard, and I think our patients would benefit from continued use for these problems. I think those three points sum it up for me," Taylor says.

SOURCES: U.S. Government Printing Office, Federal Register, Aug. 29, 2006; vol 71: pp 51146-51155. Susan Taylor, MD, Society Hill Dermatology, Philadelphia, Skin of Color Center, New York.

By Miranda Hitti, WebMD, August 30, 2006

Aug
30
2006

Combating Cultural Stress

By Howard Murad, MD

Find out how spa professionals can combat cultural stress in today's society.

Aug
30
2006

Improper Use of Sunscreens Can Harm Skin

Unless it's continuously reapplied, sunscreen can actually attack the skin and leave it vulnerable to ultraviolet (UV) radiation, concludes a University of California, Riverside study.

The researchers found that, over time, molecules in sunscreen that block UV radiation can penetrate into the skin and leave the outer layer susceptible to UV, CBC News reported.

The study appears in an upcoming issue of the journal Free Radical Biology & Medicine.

"Sunscreens do an excellent job protecting against sunburn when used correctly," Kerry Hanson, a research scientist in the university's department of chemistry, said in a prepared statement.

"This means using a sunscreen with a high sun protection factor and applying it uniformly on the skin. Our data show, however, that if coverage at the skin surface is low, the UV filters in sunscreens that have penetrated into the epidermis can potentially do more harm than good," he said.

HealthNews Day, 8/29/06

Aug
29
2006

Three Treatments Slow Skin Cancer

Acid skin peel, laser resurfacing, and a chemotherapy cream all remove precancerous skin growths and slow cancer -- but patients prefer the peel.

Precancerous growths, small areas of discrete roughness to the skin, come from too much sun, note VA researcher Basil M. Hantash, MD, PhD, and colleagues. Particularly when a person has a lot of them, they tend to become squamous cell carcinomas: cancer.

Doctors often burn off these growths, called actinic keratoses, with liquid nitrogen. But there's evidence other ways of removing them work at least as well.

Also, the other techniques appear to do another very important thing: They slow the development of cancer.

Hantash, of Palo Alto, Calif., and colleagues compared three of these techniques in 24 men. The patients had an average age of 73; all but three had previously had skin cancers removed. Five similar patients served as an untreated comparison group.

Before treatment, the 24 men had dozens of precancerous facial growths.

The researchers treated the men with laser resurfacing, an acid skin peel, or a topical cream containing fluorouracil, a chemotherapy drug.

All treatments worked, reducing the number of precancerous skin growths by 83% (chemo cream), 89% (skin peel), and 92% (laser).

Preventing New Cancers

The treatments also seemed to slow the development of new skin cancers.

Left untreated, the patients would be expected to develop 1.7 new facial skin cancers a year.

That's pretty close to what happened in the untreated comparison group. But the treated patients had only 0.04 to 0.22 new skin cancers per year.

"In the ... acid peel arm, one cancer per 26.1 years would be expected, compared with 1 cancer per 6.79 and 4.77 years in the [laser] and [chemo cream] arms, respectively," Hantash and colleagues report.

The untreated comparison group, they calculated, had 1.57 new cancers per year: that is, one new cancer every eight months.

The patients who got the acid peel were much more compliant with treatment, and had fewer side effects than those treated with laser or chemo cream.

Hantash and colleagues note that repeated treatments may be needed. In any case, patients with precancerous facial growths must get careful follow-up care.

Because the study had several limitations -- including its small size, infrequent use of sunscreen, and a control group that was not randomly picked -- the researchers warn that their findings must be confirmed in larger studies.

Hantash and colleagues report their research in the August issue of the Archives of Dermatology.

By Daniel DeNoon, WebMD, 8/21/2006

Jul
28
2006

Sun Exposure Kills 60,000 Per Year

Overexposure to the sun's harmful ultraviolet radiation (UVR) kills 60,000 people a year, but most of these deaths are almost entirely preventable through simple protective measures, according to the World Health Organization.

UVR causes sunburn, triggers cold sores and ages the skin, according to its report, the first to outline the global health burden of sun exposure. Simple measures, such as covering up when in the sun, could cut the deaths, the BBC reported on Thursday. "We all need some sun, but too much sun can be dangerous -- and even deadly," said Dr Maria Neira, Director for Public Health and the Environment at WHO.

Of the 60,000 deaths, 48,000 are caused by malignant melanomas and 12,000 by other skin cancers, the report found. Small amounts of UVR are needed for good health and play an essential role in the production of vitamin D by the skin.

HealthDay News, 6/27/2006

Jul
21
2006

Mapping Helps Clients Beat Skin Cancer

Simply asking patients to map their moles on a drawing of their back after a monthly skin self-exam is an easy, low-cost way of reducing melanoma deaths, researchers report.

Melanoma is the deadliest form of skin cancer. It has a 95 percent survival rate if it's detected early but only a 16 percent survival rate if it's detected after it has begun to spread.

One of the best methods of detecting melanoma and other skin cancers is for patients to conduct monthly skin self-exams. However, it can be difficult for patients to accurately examine their skin without a method of remembering the location and size of existing moles, the study noted.

"Most melanomas are discovered by patients. So, we looked for a way to improve the accuracy of skin self-exams. Conducting the skin self-exam with the help of a diagram showing the location of moles, scars and other marks on the skin can help a person more easily notice any changes or new lesions, which are important warning signs for melanoma," study co-author Dr. Martin A. Weinstock, of Veterans Affairs Medical Center in Providence, R.I., said in a prepared statement.

The study, published in the August issue of the Journal of the American Academy of Dermatology, included 88 people who were educated about skin cancer and skin self-examination. The researchers took digital photos of the patients' upper and lower backs and instructed the patients to perform a self-exam before their next visit.

The patients were randomly selected to receive either a blank piece of paper (46 patients) or a "mole-mapping diagram" (42 patients). Those who received the diagram were told to draw their moles on it before their return appointment.

Between the patients' initial and return visits, the researchers randomly altered the photographs of the patients' backs, adding the image of a lesion. On their return visit, the patients were asked to indicate any changes on their photos.

Of the patients who received the mole-mapping diagrams, more than half were able to identify the changes made to their photos.

"The results suggest that asking the participants to create a mole-mapping diagram may improve the accuracy of skin self-exam, particularly identifying a new lesion," Weinstock said.

HealthDay News, 7/20/06

Jul
12
2006

Melanoma Education Protects Patients' Siblings

Educating the siblings of melanoma patients about their own cancer risk encourages them to undergo regular skin self-examinations that can catch the disease early, researchers report.

"For skin self-examination, we found that an intensive education intervention has a moderately strong effect among siblings of melanoma patients -- with intervention increasing the likelihood they will carefully examine their skin by 82 percent," said study author Alan Geller, a research associate and professor in the department of dermatology at the Boston University School of Medicine.

Experts estimate that the brothers and sisters of people with melanoma face two to eight times the usual risk for the disease.

However, the Boston study found that melanoma education does not boost the use of sunscreen or visits to the dermatologist in this high-risk group.

Melanoma arises from pigmented cells called melanocytes which can rapidly spread throughout the body. Prolonged exposure to the ultraviolet rays of the sun or a tanning bed elevate the risk for developing the disease.

According to the American Cancer Society, roughly 62,000 Americans will be diagnosed with melanoma this year, and more than 7,900 will die as a result. The researchers note that almost 630,000 Americans are already living with the cancer.

Such figures underscore the fact that melanoma is a growing problem in the United States. Diagnoses are up by a factor of 15 over the last 50 years, the authors noted. And while other cancer death rates having been dropping in recent decades, melanoma mortality numbers have risen by 28 percent over the last 25 years.

To gauge to what degree screening education might improve early detection among high-risk groups, Geller and his team focused on 494 brothers and sisters of 360 patients diagnosed with melanoma in the Boston vicinity shortly before the two-year study began in 1998.

All the siblings were white and over the age of 18. Almost all had health insurance, and none had a prior melanoma diagnosis.

A little less than half the siblings participated in a one-year screening education program, where they were offered a combination of motivational and counseling support by phone, printed material specifically tailored to each patient, and information on free screening facilities.

The other half of the siblings received no intervention beyond what the researchers viewed as "standard procedure": the informing of the initial melanoma patient that his or her siblings and parents are themselves at higher risk for the disease and should seek screening.

Surveys were conducted at the start of the study and six and 12 months down the line, although not all the patients completed all the polls.

The researchers found that after six months, siblings exposed to the program had better improvements in their knowledge about melanoma. By 12 months, participants in the program had fewer practical or psychological obstacles (such as how to find and pay for a dermatologist, or disliking sunscreens) to keeping watch on their skin, seeing a doctor, or using sun protection.

Most important, the program participants were more likely to conduct a careful self-examination compared to non-participants.

By six months, 67 percent of the participants conducted thorough self-exams, including examining the back, as compared with 52 percent of non-participants.

However, the education effort did not impact on either the routine use of sunscreens or wearing sun-protective clothing.

As well, no difference between the groups was found for seeking a dermatologist-conducted screening, although the frequency of such screenings doubled among all the siblings by 12 months.

The news is still good, however, because self-exams are the most basic form of spotting melanoma.

"I'm pleased with the results," said Geller, "because I think skin self-examination is a really important technique that should be learnt. And the beauty of this whole thing is that melanoma is the only visible tumor. So every family member can play really strong role in this -- helping if the subject can't look at his or her back. So this is basically a family education program."

Marianne Berwick, head of the Cancer Epidemiology and Prevention Program at the University of New Mexico Health Sciences Center, Albuquerque, said the study has the potential to help health professionals promote early detection and lower the melanoma death rate.

"Of course, we don't yet have any direct proof that skin self-examination will prevent mortality," said Berwick, who is also associate director for population science for the Cancer Research and Treatment Center at the university center. "But it's something that we think might help. So, my view is that this finding will be a valuable building-block in helping to direct a cancer-education message that will get people to engage in efforts that could be helpful in the long-run."

A second study, also published in the August issue of Cancer, further explored the potential benefits of melanoma education interventions.

A team of Australian researchers found that men over the age of 50 are more likely to get screened for the disease if they are fully informed about major risk factors and are encouraged by their doctor.

The authors, led by Joanne Aitken of the Viertel Centre for Research in Cancer Control at the Queensland Cancer Fund in Brisbane, focused on the screening habits of 3,355 men over the age of 50 who were exposed to a melanoma education effort targeted at people over the age of 30.

Although the intervention boosted screening generally, clinic data revealed that the strongest rise occurred among men over 50.

Aitken and her colleagues noted that among males 50 and over, self-exams doubled by the end of the program, while physician-led screenings increased four-fold.

Phone surveys revealed that the screening increases among the men were linked to a better recognition of their own risk factors, a more positive outlook on screening, and concern over an existing mole or having undergone a prior removal of a mole.

Increased awareness is important among this group, the researchers said, because men over 50 currently account for almost half of all melanoma deaths in developed countries.

By Alan Mozes, HealthDay News, July 12, 2006

Jun
22
2006

Hormones May Hold Clues to Healthy Aging

Specific hormones may play a key role in longevity and healthy aging, two new studies suggest.

Researchers found one hormone, adiponectin, at higher-than-average concentrations in 100-year-old women, while another study found that stimulating the body's production of growth hormone brought a youthful pep back to people in their 60s to 80s.

Both studies were presented Wednesday at the 6th International Congress of Neuroendocrinology, in Pittsburgh.

In the first study, Dr. Agnieszka Baranowska-Bik and colleagues from the University of Poland studied 133 women from 20 to 102 years of age, including 25 women who were 100 to 102 years old. The researchers were particularly interested in the women's levels of adiponectin.

Adiponectin is made by fat tissue and may be an important determinant of longevity. It is a peptide protein with anti-inflammatory properties that helps keep blood vessels clear of fatty deposits. Adinopectin also plays an important role in metabolism, particularly in the regulation of cholesterol and sugar.

Low levels of adiponectin may contribute to obesity, insulin resistance, diabetes or plaque deposits in the arteries. This combination of conditions is also called metabolic syndrome.

"We found significant differences in the centenarian women compared to other groups," Baranowska-Bik said. "We found that our centenarian women were healthier than the other women."

"The most important finding was that adiponectin levels were significantly higher in centenarian women," Baranowska-Bik added. "This may be connected with metabolic status and also with getting old and longevity."

The Polish team found that the "100-plus" group of women, in addition to having significantly higher levels of adiponectin, also had much lower levels of both insulin and the fat hormone leptin. They also scored better with respect to insulin resistance and total cholesterol.

Moreover, compared with the obese women, the oldest women had significantly fewer signs of high blood pressure and other symptoms of metabolic syndrome. "In addition, these women had significantly lower incidence of high cholesterol and insulin resistance, which are the symptoms of metabolic syndrome," Baranowska-Bik said.

The second study dealt with improving physical functioning in older adults by increasing the body's production of growth hormone.

Aging results in a lower level of growth hormone that, in turn, brings on steady declines in muscle mass, strength and exercise capacity. This can lead to a level of frailty that brings an end to independent living.

Lead researcher Dr. George R. Merriam, of the University of Washington/VA Puget Sound Health Care System, said his team sought to determine if hormonal and functional declines were related, and if boosting growth hormone levels might help halt or reverse that decline.

In their study, Merriam and his colleagues studied the effect of the growth-hormone stimulator capromorelin on 395 men and women 65 to 84 years old. Capromorelin is an investigational medication developed by the Pfizer drug company.

All of the participants had some mild limitation in their physical functioning. During the year of the trial, some patients received capromorelin, while others were given a placebo.

Merriam's group found that, compared with a placebo, capromorelin, at any dose, caused an increase in growth hormone production. In clinical terms, this treatment resulted in an increase in muscle mass, improved heel-to-toe walking, and better stair-climbing ability.

"After six months people on the active drug showed improvement in tandem walking, and they continued to show improvement at 12 months," Merriam said. "At 12 months there was also a significant improvement in stair-climbing in the treatment group."

But whether capromorelin will be available commercially anytime soon is problematic, Merriam said.

"It's very difficult to get a drug for normal aging on the market, because the FDA does not consider aging to be a disease and therefore sets the bar very high," he said. "I would not consider these results conclusive. Drugs in this category may have hope for improving physical function and thereby hopefully prolonging older people's ability to live independently."

One expert is cautious about supplementing hormone levels to fight aging, because scientists simply doesn't yet understand the consequences of long-term use of these agents.

"The problems with all the hormones is that they have other effects," said Rafael de Cabo, an investigator at the Laboratory of Experimental Gerontology, part of the U.S. National Institute on Aging.

There can be many possible unintended effects, de Cabo said. "Before you can even think of giving these to humans, you have to be sure it is safe and doesn't have other implications," he said.

"Any time you try to tweak the neuroendocrine system, all the knobs are interconnected, so if you move one up or down there is an immediate response from the rest of them," de Cabo said. "It is not a golden bullet or an easy shot to fix the metabolism by a single compound."

By Steven Reinberg, HealthDay News, June 21, 2006