日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

   

Genetic keys to inherited hair loss found

(Agencies)
Updated: 2008-02-25 13:22

PARIS -- Researchers have found the genetic basis of two distinct forms of inherited hair loss, opening a broad path to treatments for thinning locks, according to a pair of studies released Sunday.


A bald model displays an outfit at a fashion show in this file photo. [Agencies]

Creeping baldness is a source of distress to tens of millions the world over.

Hair-challenged adults spend upward of a billion dollars every year on mostly bogus remedies in the United States alone, according to the Federal Drug Administration.

They also lavish at least as much on sometimes painful hair implants and other forms of more or less convincing hair substitutes.

Geneticist Regina Betz of the University of Bonn and her colleagues hunted down a gene -- P2RY5 -- that causes a rare, inherited form of hair loss called Hypotrichosis simplex.

They found their quarry, after six years of research, among families in Saudi Arabia.

It is the first receptor in humans known to play a role in hair growth, according to the study, published in Nature Genetics.

"Although Hypotrichosis simplex is very uncommon, it may prove critical in our search for an understanding of the mechanisms of hair growth," said Betz.

The disease affects both men and women, who begin to go bald during childhood.

At fault is a genetic defect that prevents certain receptors on the surface of hair follicle cells from being correctly formed.

For the hair follicle to function normally, messengers must bind to these receptors, triggering a chain reaction in the cell interior.

The fact that a receptor plays a specific role in hair growth was previously unknown to scientists.

"We can now search selectively for related substances that may be used in therapies for very different types of hair loss," said Ivar von K??gelgen of from Bonn's Institute of Pharmacology and Toxicology.

In the other study, Angela Christiano of Columbia University lead a team that found another mutation of the same gene that results in "woolly hair" -- sparse, dry and tightly curled hair over the entire scalp.

Examining families in Pakistan, the researchers determined that the mutation is expressed in the inner root sheath of hair follicles, which anchor and shape individual hairs.

Until recently, many scientists assumed that mammalian hair follicles were a non-renewable resource.

The human head comes equipped with approximately 100,000 of these tiny, hair-generating organs, and once they stop working, it was thought, the scalp was doomed to gradual exposure.

A healthy individual loses around a hundred hairs a day, but they are normally replaced at the same rate.



Top World News  
Today's Top News  
Most Commented/Read Stories in 48 Hours
主站蜘蛛池模板: 黄色av成人 | 免费毛片网 | 成人免费网站在线观看 | 国内久久久 | 成人国产精品 | 日韩视频区| 天天综合天天干 | 亚洲精品国产欧美在线观看 | 亚洲一区二区三区欧美 | 91成人小视频 | 亚洲精品一区二区三区在线观看 | 天堂中文字幕在线观看 | 99精品久久久 | 天天综合91| 在线观看毛片网站 | 丁香婷婷色 | av片在线看| 一级片黑人| 国产一区二区不卡视频 | 日本一区久久 | 国产精品一区二区性色av | 欧美aaa级 | 亚洲精品影片 | 国产色一区 | 女人高潮特级毛片 | 美丽姑娘在线观看免费 | 国产免费一区二区 | 黄色三级三级三级三级 | 日本精品一区二区 | 国产精品一区二区三区四区五区 | 精品毛片一区二区三区 | 日韩毛片在线观看 | 99热精品在线播放 | 国产特黄一级片 | 诱惑の诱惑筱田优在线播放 | 欧美日韩久久久久久 | 黄色xxx | 黄色大片黄色大片 | 欧美视频在线观看免费 | 日韩影视一区二区三区 | 五月婷婷六月香 |