| Latest Related Articles
About Skin Cancer |
|
Melanoma Cancer |
|
Melanoma is a skin disease where cancerous cells grow in the melanocytes, the cells that generate skin color. Melanoma is either known as malignant melanoma or cutaneous melanoma. Of all types of skin cancer plaguing mankind, melanoma is considered the most serious. The epidermis, or the topmost layer of the skin, contains three types of cells liable to become cancerous. Those are squamous cells, basal cells and melanocytes. Squamous cell cancer and basal cell cancer are known as non-melanoma skin cancers. They are more widespread than melanoma. Melanoma, which is relatively less common than the other two, is indubitably more serious and complicated to treat than either squamous cell... |
|
|
Myths About Skin Cancer Are You Safe? |
|
Sara spends much of her summer near the beach. She lives in a mild climate and is very athletic. She loves to swim, bike and play games outdoors. Sara knows the dangers of the sun and so she opts for tanning salons to get her 'golden glow' while being sure to apply sunscreen every day before heading out. Joseph lives in a cooler, northern climate. The summers can be very humid, but most of the year is mild or even below freezing during the harshest winter months. The beach has never been much of a draw for him and he spends most of his time doing indoor activities or at his job. Joseph doesn't worry about sunscreen and only had one sunburn that he can remember and that was when he was a... |
|
|
New Approach Prevents Skin Cancer Using Photodynamic Therapy (PDT) |
|
Every year there are more new cases of skin cancer than breast, prostate, lung and
colon cancers combined. One in 5 Americans will get skin cancer in their lifetime.
90% of skin cancers are caused by excessive sun exposure, yet fewer than 33
percent of adults, adolescents, and children routinely use sun protection. Cancer prevention and early detection techniques could eliminate up to 100,000
cancer cases and 60,000 US cancer deaths each year. New technologies in the
evaluation and treatment of sun damaged skin could have a positive impact on
changing these statistics. The same sunny weather that attracts so many tourists and new residents to the
sun-belt also... |
|
|
| Looking For More Articles Related To Skin Cancer? |
Skin Cancer Symptoms Poll |
|
|
| |
|
| |
| |
| |
Melanin: Aging of the Skin and Skin Cancer
Author:
Diana Clarke
"Ultraviolet (UV) radiation is responsible for 90% of the visible signs of aging on the skin of whites," says Dr. Michael J. Martin, former Assistant Clinical Professor in the Dept. of Epidemiology and Biostatistics at University of California, San Francisco.
Blacks' skin, however, ages much slower.
Why are most dark-skinned blacks protected from harmful UV rays? Because compared to whites, blacks possess more melanin, the pigment that gives skin its color.
Melanin
Melanin offers protection against UV rays for blacks and other dark-skinned people. Conversely, fair-skinned people are much less protected and more susceptible to skin cancer. Furthermore, albinos' skin offers no protection.
Although blacks' skin produces more melanin than whites', all skin has the same number of melanocytes, the cells that manufacture the melanin.
Melanocytes manufacture melanin from an amino acid, tyrosin, with the help of an enzyme, tyrosinase. In the bottom layer of the epidermis above the dermis, UV light stimulates the production of melanin in the form of insoluble melanosomes. These surround the epidermal cells, which move up to the surface of the skin. The result is a tan.
Blacks' skin produce more melanin, even in the absence of sunlight, and their type of melanin, eumelanin, is more effective at blocking solar rays. However, white skin produces melanin only in the presence of sunlight and after the UV rays have penetrated the lower portion of the epidermis and have caused skin damage.
"Melanin also functions as an excellent free radical scavenger. It affects the delicately designed lipids that hold moisture in the stratum corneum (the outermost layer of the epidermis). If the skin loses its moisture, it becomes rigid and cracks," says Sergio Nacht, PhD., Senior Vice-President of Enhanced Derm Technologies, Inc. in Redwood City.
UV Radiation and Skin
UV-A has the longest wavelength, is not filtered by the ozone and passes through glass. It reaches the earth all year long and the amount is comparatively stable. It can penetrate the skin down to the dermis, beneath the four layers of epidermis. It is responsible for most of the visible signs of aging, due to damage to collagen and elastic fibers of the connective tissue of the dermis.
UV-A radiation also plays a role in the development of sunburns and skin cancer. Tanning salon lamps emit a large amount of UV-A rays to generate tans, so the American Academy of Dermatology does not recommend their use.
UV-B radiation, which is partially filtered by the ozone, penetrates the skin to the bottom layer of the epidermis where the basal cells are produced. UV-B can break the molecular bonds, disturbing the dividing cells and altering their structure. Compared with UV-A, UV-B is responsible for most of DNAs damage. It also causes most sunburns. During a sunburn the reddening of the skin, erythema, is caused by dilation of capillaries.
More UV-B is present during summer months between 10 a.m. and 4 p.m. and at latitudes closer to the equator. Furthermore, at high altitudes the air is thinner and cleaner, so UV-B radiation is more abundant.
UV-C, which is generally filtered by the ozone, has the shortest wavelength and the most energy, or intensity. It can sterilize hospital equipment and kill bacteria.
In addition, UV light that reaches the earth is scattered in all directions, and up to 85% is reflected from surfaces.
The Theory of Melanin for Environmental Adaptation
Originally, people of a particular race resided in a particular area. As time went on, their skin adapted to the environment. For instance, people who lived geographically close to the equator had darker skin, and people who lived far from the equator had lighter skin.
In Scotland, which lies at a northern latitude, descendants of the Britons have white skin. When their skin is exposed to the meager sunlight, the scant amount of melanin their skin produces is unable to block the sunlight. Therefore, their bodies are able to make Vitamin D with the help of sunlight. Vitamin D, a vitamin found in fish oil, is necessary to prevent rickets, a bone disease caused by too little calcium.
In contrast, in Africa, which is near the equator, blacks require intense sunlight to penetrate their dark skin to make Vitamin D. This is all well and good. However, when blacks lived in England during the Industrial Revolution, they were the first to develop symptoms of rickets, such as retarded growth, bowed legs and fractures because not enough sunlight was available.
Fortunately, in 1930, Vitamin D was discovered and dispensed as a supplement to add to the diet.
On the other hand, the skin of whites in Australia are in complete opposition to their climate. Consequently, intense UV radiation has been the major cause of skin damage and skin cancer Down Under.
Diana Clarke is a teacher, freelance writer and founder of The Sun and Your Skin, a website on life and light at http://www.yourskinandsun.com.
dianaclarke2001@yahoo.com
|
Article Keywords:
Skin Cancer |
|
A Quick Note
From The Publisher...
If you like the article above, you may be
interested in the following article which is also related to Skin Cancer...
|
Are Redheads More Prone to Skin Cancer? |
|
Everyone knows that redhead sunburn easier. But do they get skin cancer easier? New research indicates that the pigment in their skin may instigate cancer even if they don't suffer from sunburns. As you may have heard, getting sunburns in childhood is a risk factor for skin cancer, even later in life. Who is prone to sunburn? Of course if you have light colored eyes, hair and skin, you are at higher risk. This combination is frequent among redheads. Redheads have a different type of melanin than people with dark hair. Blondes even carry some of the same pigments as redheads. Duke University said that the melanin in redheads is more vulnerable to damage from the sun's UV rays. Redheads, under exposure to the sun, developed a reaction of oxidative stress. This is where damage to DNA and cells may occur and over time, form cancer. Research used UVA and UVB rays for testing. UVA can cause damage without burning. Sunscreens protect against UVB, but its not been shown to help against UVA. Sure, some protection is there, but the FDA will need to set guidelines for consumers. It all boils down to this: wear sunscreen and put it on your kids. Here's what you do: Apply plenty of sunscreen with an SPF of 15 or higher and reapply every 2 hours or as indicated on the bottle. Reapply after swimming, sweating, even drying with a towel. Apply even during cloudy days. Avoid the sun in the middle of the day. 10 and 4 is indoor time. Wear a hat, clothing and sunglasses. Take care of the kids. Overexposure early in life may lead to skin cancers later in life. Even so, the FDA has a warning label: "Warning -This product does not contain a sunscreen and does not protect against sunburn. Repeated exposure of unprotected skin while tanning may increase the risk of skin... |
|
|
|
|
|
