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New in Physiology (page 62 of 65)
Women's skin ages faster than men's, suggests a study that used an experimental laser device to measure skin damage.
Researchers in Germany used the device to determine collagen and elastin levels beneath the skin's surface. Collagen and elastin are the proteins responsible for the elasticity, tone, and texture of skin, and levels typically decline with age.
There is no good way to assess skin, as measured by collagen and elastin composition, short of removing skin and analyzing it in a lab.
The laser procedure shows promise for making the process a whole lot simpler. That could one day help consumers better evaluate the effectiveness of the antiaging skin products they buy, researcher Martin Johannes Koehler, of Germany's Schiller University, tells WebMD.
"Some cosmetics are thought to change the content of collagen to the skin, but until now to measure that you had to cut out a piece of skin," he says.
Multiphoton Laser Imaging
The search for a noninvasive test to measure damage to the skin from sun exposure and aging is the Holy Grail of the cosmetics industry.
But proving that a skin cream that promises to turn back the clock really is worth $100 an ounce is only one potential application for the experimental laser technique, Koehler says.
It may also prove useful for evaluating skin diseases like that seen in, which is a serious autoimmune disease, as well as a skin complication that can occur in transplant recipients, known as graft vs. host disease.
Koehler and colleagues used the technique, called multiphoton laser imaging, on the inner forearms of seven women and 11 men between the ages of 21 and 84.
The researchers used the information gathered from the imaging to develop an aging index of the dermis, an inner layer of the skin. Skin aging was more evident in women than in men of similar age. It was most marked in older women who had been through.
The researchers wrote that menopause-related declines in the sex hormones estrogen and progesterone might explain this acceleration in skin aging.
More Study Needed
But they added that more research is needed to confirm the finding that men and women's skin ages at different rates. The researchers also note that studies comparing their aging index measurements need to be compared to established measures such as skin surface hydration and wrinkle number and depth.
The study is published in the Oct. 1 issue of the journal Optics Letters.
Cosmetic dermatologist Eliot Battle, MD, tells WebMD that the laser procedure is one of several promising experimental techniques that could help clinicians more easily diagnose and treat skin diseases.
"Diagnostic tools like this have been used in every area of medicine, but they are only beginning to be used in dermatology," he says. "This [technique] is an attempt to use the latest and greatest in laser imaging, but much more research is needed. This is just the very beginning of what could be an exciting journey."
SOURCES: Koehler, M.J. Optical Letters, Oct. 1, 2006; vol 31: pp 2879-2881. Martin Johannes Koehler, department of dermatology and allergology, Friedrich Schiller University, Jena, Germany. Eliot Battle Jr., MD, cosmetic dermatologist and laser surgeon, Cultura Cosmetics Medical Spa, Washington, D.C.
By Salynn Boyles, WebMD, October 4, 2006
An antibiotic-resistant acne germ can spread among family members, Swedish researchers find.
The germ is Propionibacterium acnes. Skin colonized by P. acnes tends to erupt into the blotches and pustules of acne. Since the 1960s, doctors have fought P. acnes with antibiotics. The bug fought back. It's now common to find P. acnes strains resistant to several common antibiotics.
Doctors hoped that the only people carrying the drug-resistant acne bugs would be patients on long-term antibiotic therapy. That isn't the case, find Carl Eric Nord, MD, PhD, and colleagues at Karolinska Institute in Stockholm, Sweden.
Nord and colleagues took skin samples from 10 acne patients, all on antibiotic therapy, and from two close family contacts of each patient. Twelve healthy, acne-free volunteers -- who were not taking antibiotics and did not have family members with acne -- served as a comparison group.
Nord and colleagues found that nearly half of the family members carried drug-resistant acne bacteria on their skin. Genetic analysis showed that these family members carried the same strain of P. acnes as the acne patient among them.
The good news is that the family members fought off the drug-resistant germs -- but only after the acne patient in their family stopped using antibiotics.
On the other hand, you apparently can't avoid drug-resistant acne germs by avoiding people with acne. A third of the healthy comparison group also carried drug-resistant P. acnes on their skin.
Nord reported the findings at last week's 46th Interscience Conference on Antimicrobial Agents and Chemotherapy, held Sept. 27-30 in San Francisco.
SOURCES: 46th Interscience Conference on Antimicrobial Agents and Chemotherapy, San Francisco, Sept. 27-30, 2006.
By Daniel DeNoon, WebMD, October 2, 2006
"Easy on the mind" rather than "easy on the eyes" may be a better way to describe something that’s beautiful, according to a new study.
Researchers found objects and animals that conform to a prototype rather than deviate from it are easier for the brain to process and, therefore, are perceived as more pleasing to the eye.
"What you like is a function of what your mind has been trained on," says researcher Piotr Winkielman of the University of California, San Diego, in a news release. "A stimulus becomes attractive if it falls into the average of what you've seen and is therefore simple for your brain to process. In our experiments, we show that we can make an arbitrary pattern likeable just by preparing the mind to recognize it quickly."
Researchers say the findings build a phenomenon known as "beauty-in-averageness effect," which was discovered in the late 1800s. The theory holds that prototypical images are rated as more beautiful or appealing than variations of the same thing.
To test the theory, researchers had groups of students undergo different experiments. In one experiment, a group of students were presented prototypes of random groupings of dots. Then distortions of the dots in these prototypes were created and presented to the students.
In a second experiment, a group of students rated the attractiveness of random dot patterns and those that conformed to common geometric patterns, like a diamond or square.
The results, published in Psychological Science, showed that the participants categorized patterns quicker and rated them as more attractive when they were closer to their respective prototypes.
A third experiment had students looking at dots also, but this time also examined cheek muscle for smiling action and brow muscle for frowning action.
Researchers also found that the less time it took participants to classify a pattern, the more attractive they found it.
"This parsimonious explanation," says Winkielman, "accounts for cultural differences in beauty -- and historical differences in beauty as well -- because beauty basically depends on what you've been exposed to and what is therefore easy on your mind."
SOURCES: Winkielman, P. Psychological Science, September 2006; vol 17: pp 799-806. News release, University of California, San Diego.
By Jennifer Warner, WebMD, September 29, 2006
Melanoma surgery may get more aggressive to help plan treatment and ultimately improve survival.
A study and editorial in The New England Journal of Medicine support checking the "sentinel" lymph node near melanoma for signs of.
Melanoma is the most serious type of, with more than 53,600 new cases per year diagnosed in the U.S., according to the National Cancer Institute.
The body's lymph system makes, stores, and carries white blood cells that fight infections and other diseases. Lymph nodes are part of the lymph system; they're clustered around the body.
Cancer can spread to lymph nodes. It usually first shows up in one or two "sentinel" nodes that are closest to the cancer site.
In sentinel lymph node biopsy, doctors surgically check the sentinel lymph node or nodes for signs of cancer.
If the biopsy shows cancer in the sentinel node or nodes, that means cancer has spread beyond its original location and would be more likely to be in the other lymph nodes in the area. Sentinel node biopsies are also used with other types of cancer, including.
Sentinel Node Study
The new study comes from researchers including Donald Morton, MD, of the John Wayne Cancer Institute at Saint John's Health Center in Santa Monica, Calif.
Morton's team studied 1,269 people who had surgery to remove isolated skin melanomas of medium thickness.
The researchers randomly assigned 60% of the patients to get sentinel node biopsy. Patients with cancerous sentinel nodes had all the other lymph nodes near the sentinel nodes removed.
The remaining 40% of the patients got careful checkups every few months, without sentinel node biopsy. They kept all of their lymph nodes unless doctors suspected cancer's spread, which happened months or even years later.
Why not just automatically remove all lymph nodes closest to a melanoma? Doing so could have complications and offers no advantage if those nodes are cancer-free.
The researchers followed the patients for five years.
During that time, the overall survival rate between the two groups was similar (around 87%).
But there was an important exception for patients with cancerous lymph nodes.
Of the patients who got sentinel node biopsies that showed cancerous sentinel nodes and had their nearby lymph nodes immediately removed, 72% were alive five years later.
But the five-year survival rate was much lower -- 52% -- for patients with cancerous lymph nodes that were spotted later because they didn't get sentinel lymph node biopsy.
In patients with skin melanomas of medium thickness, sentinel node biopsy "should be preferred to observation," write Morton and colleagues.
That conclusion is "convincing" and "justified," based on the study's results, write editorialists Charles Balch, MD, and Natale Cascinelli, MD.
Balch works in Baltimore, Md., at the Johns Hopkins Medical Institutions. Cascinelli works at the National Tumor Institute in Milan, Italy.
SOURCES: Morton, D. The New England Journal of Medicine, Sept. 28, 2006; vol 355: pp 1307-1317. Balch, C. The New England Journal of Medicine, Sept. 28, 2006; vol 355: pp 1370-1371. National Cancer Institute: "What You Need to Know About Melanoma."
By Mirandi Hitti, WebMD, September 27, 2006
By Judi Bailey
Learn more about identifying this disorder and helping clients who demonstrate its symptoms.
Fair-skinned people who yearn for a suntan -- even though they know it's hopeless and unhealthy -- may one day have cause for celebration.
Harvard scientists have discovered new information about how the skin tans or -- in the case of fair-skinned people -- stubbornly refuses to tan due to a genetic defect. Using a skin treatment, they have turned pale skin dark, while also protecting it from ultraviolet-induced.
"Darkening a person's skin may mimic the protective benefit seen in people who otherwise make a large amount of pigment," says researcher David E. Fisher, MD, PhD, director of the Melanoma Program at Dana Farber Cancer Institute in Boston. And that could translate into a reduction in the toll of the potentially deadly skin cancer melanoma, expected to be diagnosed this year in 62,000 people in the U.S. and to result in 8,000 deaths, according to American Cancer Society projections.
The study appears in the Sept. 21 edition of the journal Nature. Fisher cautions that the study was done only in animals. Using a topical cream instead of the sun's rays, Fisher's team was able to switch on the tanning mechanism in the skin cells of fair-skinned mice, turning them into olive-skinned animals. "This has not been demonstrated in people and there is a lot that needs to be proven before it's ready for even a first attempt in clinical subjects," Fisher says.
Even so, the study was called intriguing by Meenhard Herlyn, DVM, PhD, a tumor biologist at The Wistar Institute, a research center on the campus of the University of Pennsylvania. "What he clearly has shown is ... you can induce a pigmentation, tanning, and the purpose is that people who are very susceptible to skin cancer, including melanoma, can be protected."
By Kathleen Doheny, WebMD, September 20, 2006
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
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 firstname.lastname@example.org.
The FDA is seeking to ban over-the-counter sales of skin bleaching drug products.
The FDA cites the possible risk ofand 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.
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,, , 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
By Howard Murad, MD
Find out how spa professionals can combat cultural stress in today's society.