久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

   

Tanning cream may ward off skin cancer
(Reuters)
Updated: 2006-09-21 09:03

BOSTON - Scientists say they have discovered a cream that may ward off skin cancer by tanning skin a golden bronze without exposure to the sun.

Tests so far have been confined to mice, but researchers at the Dana-Farber Cancer Institute and Children's Hospital in Boston say the findings would mark a seismic shift in the biology of tanning if the cream was determined to be safe for humans.

Unlike sunless tanning lotions that color the skin, the cream alters skin pigmentation much like a suntan. The more days it was applied, the darker the skin became. A heavy application over more than a week left some mice nearly black.

The mice experienced no dangerous side effects, scientists said.

And researchers said the findings suggest people may be able to change their skin pigmentation to ward off skin cancers like melanoma, the world's fastest-growing cancer.

"We just kind of smeared it on once a day, five days a week. Within a couple of days you could clearly see they were becoming darker," said David Fisher, director of the Melanoma Program at Dana-Farber and senior author of the study published in the journal Nature on Thursday.

The cream "switched on the tanning machinery" in mice skin cells that were genetically designed to resemble those in blond and redheaded people, the study said.

People who tan easily, or have naturally dark skin, are far less likely to develop skin cancer than those with fair skin, the study said, a point which Fisher said underlined its potential significance in reducing cancer rates at a time when more fair-skinned people are living in sun-belts like the southern United States, Australia and the Middle East.

TESTING ON HUMANS

In the United States, melanoma accounts for 62,000 new cases of cancer a year and nearly 8,000 deaths, according to the American Cancer Society.

The molecule at the heart of the cream recreates a process that occurs naturally when ultraviolet sunlight strikes skin cells. The cells respond differently depending on a person's skin type. For people who tan well, the sun's ultraviolet rays initially harm DNA in the skin, but this is followed by a robust tanning that curbs the DNA damage.

For lousy tanners, even a light tan can inflict significant DNA damage that can lead to cancers like melanoma by causing pigment-making skin cells known as melanocytes to begin dividing rampantly. The researchers say a darkening in pigmentation can help these people reduce that risk.

"Our strategy turns on pigment but doesn't touch the DNA," said Fisher. "This actually may represent a broader strategy to prevent the damage that UV causes in the skin, shielding the skin in ways that traditional sunscreens cannot."

The next step, he said, is to test it on humans to see whether ultraviolet light follows the same path to stimulating pigment change as in the mice, which have thinner skin.

"Preliminarily it looks like it is exactly the same as human skin," Fisher, who is also a professor of pediatrics at Harvard Medical School, told Reuters.

"You could give this drug as much as you wanted," he added. "It could get to a point where it would literally turn the skin a very dark brown/black."

But he said a number of hurdles remain before determining whether it was safe for humans, including whether it would cause side effects. "The initial glimpses look promising but it's early still," he said.

 
 

久久久无码人妻精品无码_6080YYY午夜理论片中无码_性无码专区_无码人妻品一区二区三区精99

    国产一区二区三区不卡在线观看| 国产在线精品视频| 欧美老肥妇做.爰bbww| 日本色综合中文字幕| 精品美女被调教视频大全网站| 狠狠色丁香九九婷婷综合五月| 国产日韩欧美精品综合| 91在线观看美女| 香蕉成人啪国产精品视频综合网| 欧美一级艳片视频免费观看| 国产一区二区精品久久91| 中文字幕一区在线观看| 欧美色视频一区| 久久99国产精品尤物| 国产精品另类一区| 欧美视频中文字幕| 极品销魂美女一区二区三区| 亚洲婷婷综合色高清在线| 欧美日本不卡视频| 国产精品一区二区无线| 亚洲美女一区二区三区| 欧美大片在线观看一区二区| 99久久精品免费看国产| 在线看不卡av| 五月综合激情婷婷六月色窝| 久久欧美一区二区| 91国在线观看| 国产自产v一区二区三区c| 亚洲男人天堂一区| 精品国产免费一区二区三区四区 | 精品一区二区精品| 亚洲三级视频在线观看| 日韩欧美国产小视频| 91在线porny国产在线看| 蜜臀91精品一区二区三区| 中文字幕制服丝袜一区二区三区| 在线成人午夜影院| 99久久99久久免费精品蜜臀| 麻豆精品一区二区三区| 一区二区三区在线视频免费观看| 精品国产免费一区二区三区四区 | 首页综合国产亚洲丝袜| 中文字幕av一区 二区| 在线电影国产精品| 91麻豆国产精品久久| 国产一区二区三区四区五区美女| 一区二区三区免费在线观看| 久久综合中文字幕| 欧美日韩极品在线观看一区| 不卡高清视频专区| 麻豆精品在线视频| 亚洲一区在线电影| 国产精品久久久久四虎| 精品久久久久久久久久久久久久久 | 欧美一区二区三区在线观看 | 99久久综合精品| 黄色日韩网站视频| 五月天激情综合| 亚洲三级视频在线观看| 国产欧美一区二区精品性色 | 国产成人在线视频免费播放| 日产欧产美韩系列久久99| 亚洲蜜臀av乱码久久精品| 久久精品亚洲一区二区三区浴池| 91精品国产综合久久精品麻豆 | 久久久久综合网| 欧美一区二区三区喷汁尤物| 色丁香久综合在线久综合在线观看| 国产精品66部| 久久精品99国产精品日本| 一区二区三区资源| 17c精品麻豆一区二区免费| 久久久久久久久99精品| 日韩欧美一区二区三区在线| 欧美三电影在线| 色先锋资源久久综合| 成人精品高清在线| 国产成人免费在线观看不卡| 狠狠网亚洲精品| 免费高清在线一区| 欧美丝袜丝nylons| 91美女片黄在线观看91美女| 成人精品在线视频观看| 国产精品小仙女| 极品少妇一区二区三区精品视频 | 欧美精品一区二区三区蜜桃视频| 欧美二区三区的天堂| 欧美伦理电影网| 精品视频在线视频| 欧美性大战久久久久久久蜜臀| 91福利精品第一导航| 在线亚洲一区观看| 欧美主播一区二区三区美女| 91福利在线播放| 欧美制服丝袜第一页| 欧美少妇xxx| 欧美日韩一级片在线观看| 欧美色老头old∨ideo| 欧美视频一区二区三区| 欧美日韩视频第一区| 在线电影国产精品| 日韩午夜在线影院| 精品欧美黑人一区二区三区| 2023国产精品| 久久久国产精品午夜一区ai换脸| 26uuu另类欧美亚洲曰本| 久久影院视频免费| 久久久亚洲精品石原莉奈| 国产婷婷色一区二区三区在线| 中文字幕精品综合| 中文字幕综合网| 一区二区三区视频在线观看| 亚洲国产婷婷综合在线精品| 日一区二区三区| 久久精工是国产品牌吗| 国产精品中文字幕一区二区三区| 国产成人在线视频网址| 99久久精品99国产精品| 91黄视频在线| 91麻豆精品久久久久蜜臀| 精品日韩99亚洲| 国产亚洲成年网址在线观看| 国产精品成人一区二区艾草| 一区二区三区中文字幕电影| 午夜精品123| 精品亚洲成a人| 成人av网址在线| 91高清视频在线| 欧美一区二区在线不卡| 久久亚洲综合av| 综合色中文字幕| 亚洲成人福利片| 久久aⅴ国产欧美74aaa| 丁香婷婷综合网| 在线观看亚洲一区| 日韩免费成人网| 中文字幕乱码日本亚洲一区二区 | 一本色道a无线码一区v| 欧美性猛交一区二区三区精品 | 日本一区二区在线不卡| 亚洲少妇30p| 日本不卡中文字幕| 国产ts人妖一区二区| 在线亚洲免费视频| 日韩精品一区二| 日韩一区欧美小说| 日韩精品欧美精品| 国产成人免费视频网站 | 日韩一区二区免费电影| 中文在线免费一区三区高中清不卡| 色综合天天综合色综合av | 中文字幕精品在线不卡| 亚洲一区成人在线| 国产精品一区免费在线观看| 色哦色哦哦色天天综合| 欧美电影免费观看完整版| 亚洲情趣在线观看| 久久99九九99精品| 在线视频国内自拍亚洲视频| 精品久久久久久久久久久久包黑料 | 99国产欧美另类久久久精品| 69av一区二区三区| 国产精品久久久爽爽爽麻豆色哟哟| 亚洲成人激情av| 成人动漫一区二区| 91精品国产aⅴ一区二区| 国产精品久久久久久久久图文区 | 国产精品麻豆99久久久久久| 日韩精品一区第一页| 99综合电影在线视频| 欧美哺乳videos| 一区二区三区精品在线观看| 国产麻豆精品一区二区| 欧美美女直播网站| 国产精品伦理在线| 久久99精品国产麻豆婷婷 | 国产亚洲成av人在线观看导航| 午夜欧美大尺度福利影院在线看| 成人一区二区在线观看| 日韩一区二区在线看| 伊人色综合久久天天| 国产不卡视频一区二区三区| 制服丝袜中文字幕一区| 亚洲精品视频一区| 风间由美一区二区av101| 日韩一级高清毛片| 亚洲一区二区三区激情| caoporn国产一区二区| 久久久亚洲高清| 日本视频中文字幕一区二区三区| 日本乱人伦一区| 中文字幕 久热精品 视频在线 | 在线亚洲免费视频| 国产精品短视频| 国产精品一线二线三线精华| 欧美一级日韩免费不卡| 亚洲成人免费影院| 一本色道亚洲精品aⅴ| 国产精品久久久久久久久图文区| 国内精品伊人久久久久av一坑|