皮肤表面的细菌维持着皮肤的健康平衡
文章来源:未知 文章作者:meng 发布时间:2009-11-23 02:46 字体: [ ]  进入论坛
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On the skin's surface, bacteria are abundant(丰富的,充裕的), diverse(不同的,相异的) and constant(经常的,不变的), but inflammation(发炎,红肿) is undesirable(不受欢迎的,不良的). Research at the University of California, San Diego School of Medicine now shows that the normal bacteria living on the skin surface trigger a pathway that prevents excessive inflammation(严重发炎) after injury. "These germs are actually good for us," said Richard L. Gallo, MD, PhD, professor of medicine and pediatrics, chief of UCSD's Division of Dermatology and the Dermatology section of the Veterans Affairs San Diego Healthcare System.

The study, to be published in the advance on-line edition of Nature Medicine on November 22, was done in mice and in human cell cultures(细胞培养), primarily performed by post-doctoral fellow Yu Ping Lai .

"The exciting implications of Dr. Lai's work is that it provides a molecular1 basis to understand the 'hygiene2 hypothesis(卫生假说)' and has uncovered elements of the wound repair response that were previously3 unknown. This may help us devise new therapeutic4(治疗的) approaches for inflammatory skin diseases," said Gallo.

The so-called "hygiene hypothesis," first introduced in the late 1980s, suggests that a lack of early childhood exposure to infectious agents and microorganisms(微生物) increases an individuals susceptibility(感受性,感情) to disease by changing how the immune system reacts to such "bacterial5 invaders6." The hypothesis was first developed to explain why allergies7 like hay fever(花粉热,干草热) and eczema(湿疹) were less common in children from large families, who were presumably(推测上,大概) exposed to more infectious agents than others. It is also used to explain the higher incidence(发生) of allergic8 diseases in industrialized countries.

The skin's normal microflora(微生物群落) – the microscopic9(显微镜的,微观 的) and usually harmless bacteria that live on the skin – includes certain staphylococcal(葡萄球菌) bacterial species that will induce an inflammatory response when they are introduced below the skin's surface, but do not initiate10 inflammation when present on the epidermis11(表皮,上皮), or outer layer of skin.

In this study, Lai, Gallo and colleagues reveal a previously unknown mechanism12 by which a product of staphylococci(葡萄状球菌) inhibits13 skin inflammation. Such inhibition is mediated14 by a molecule15 called staphylococcal lipoteichoic acid(脂磷壁酸) (LTA) which acts on keratinocytes(角化细胞) – the primary cell types found on the epidermis.

The researchers also found that Toll-like receptor 3 (TLR3) activation16 is required for normal inflammation after skin injury.

"Keratinocytes require TLR3 to mount a normal inflammatory response to injury, and this response is kept from becoming too aggressive by staphylococcal LTA," said Gallo. "To our knowledge, these findings show for the first time that the skin epithelium(上皮,上皮细胞) requires TLR3 for normal inflammation after wounding and that the microflora helps to modulate17(调制) this response."



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1 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
2 hygiene Kchzr     
n.健康法,卫生学 (a.hygienic)
参考例句:
  • Their course of study includes elementary hygiene and medical theory.他们的课程包括基础卫生学和医疗知识。
  • He's going to give us a lecture on public hygiene.他要给我们作关于公共卫生方面的报告。
3 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
4 therapeutic sI8zL     
adj.治疗的,起治疗作用的;对身心健康有益的
参考例句:
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候,音乐有治疗效力。
5 bacterial dy5z8q     
a.细菌的
参考例句:
  • Bacterial reproduction is accelerated in weightless space. 在失重的空间,细菌繁殖加快了。
  • Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。
6 invaders 5f4b502b53eb551c767b8cce3965af9f     
入侵者,侵略者,侵入物( invader的名词复数 )
参考例句:
  • They prepared to repel the invaders. 他们准备赶走侵略军。
  • The family has traced its ancestry to the Norman invaders. 这个家族将自己的世系追溯到诺曼征服者。
7 allergies 2c527dd68e63f119442f4352f2a0b950     
n.[医]过敏症;[口]厌恶,反感;(对食物、花粉、虫咬等的)过敏症( allergy的名词复数 );变态反应,变应性
参考例句:
  • Food allergies can result in an enormous variety of different symptoms. 食物过敏会引发很多不同的症状。 来自辞典例句
  • Let us, however, examine one of the most common allergies; hayfever. 现在让我们来看看最常见的变态反应的一种--枯草热。 来自辞典例句
8 allergic 4xozJ     
adj.过敏的,变态的
参考例句:
  • Alice is allergic to the fur of cats.艾丽斯对猫的皮毛过敏。
  • Many people are allergic to airborne pollutants such as pollen.许多人对空气传播的污染物过敏,比如花粉。
9 microscopic nDrxq     
adj.微小的,细微的,极小的,显微的
参考例句:
  • It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
  • A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。
10 initiate z6hxz     
vt.开始,创始,发动;启蒙,使入门;引入
参考例句:
  • A language teacher should initiate pupils into the elements of grammar.语言老师应该把基本语法教给学生。
  • They wanted to initiate a discussion on economics.他们想启动一次经济学讨论。
11 epidermis AZhzW     
n.表皮
参考例句:
  • The external layer of skin is called the epidermis.皮的外层叫表皮。
  • There is a neoplasm originating in his leg's epidermis.他的腿上有个生长在表皮上的肿瘤。
12 mechanism zCWxr     
n.机械装置;机构,结构
参考例句:
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
13 inhibits 7fbb1ac5e38d9e83ed670404679a2310     
阻止,抑制( inhibit的第三人称单数 ); 使拘束,使尴尬
参考例句:
  • A small manufacturing sector inhibits growth in the economy. 制造业规模太小有碍经济增长。
  • His bad English inhibits him from speaking freely. 他英语学得不好,这使他不能表达自如。
14 mediated b901b5da5d438661bcf0228b9947a320     
调停,调解,斡旋( mediate的过去式和过去分词 ); 居间促成; 影响…的发生; 使…可能发生
参考例句:
  • He mediated in the quarrel between the two boys. 他调解两个孩子之间的争吵。
  • The government mediated between the workers and the employers. 政府在工人与雇主间搞调和。
15 molecule Y6Tzn     
n.分子,克分子
参考例句:
  • A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈?f婘??妈?成的。
  • This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
16 activation 24eed33ee38027d124839f0fcdf6adcb     
n. 激活,催化作用
参考例句:
  • A computer controls the activation of an air bag.电脑控制着气囊的启动。
17 modulate IEOxl     
v.调整,调节(音的强弱);变调
参考例句:
  • Please modulate the sound on the TV.请调节一下电视的音量。
  • This system could modulate the voice signal effectively.这个系统可以对语音信号进行有效的调制。
TAG标签: skin bacteria surface
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