新研究揭示肝硬化的病变过程-凯发k8官网

新研究揭示肝硬化的病变过程
文章来源:未知 文章作者:meng 发布时间:2010-12-21 02:06 字体: [ ] 
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in the latest of a series of related papers, researchers at the university of california, san diego school of medicine, with colleagues in austria and elsewhere, present a new and more 1 explanation of how fibrotic(纤维化的) cells form, multiply and eventually destroy the human liver, resulting in cirrhosis(肝硬化) . in doing so, the findings upend(倒放,颠倒) the 2 of a long-presumed marker for multiple fibrotic diseases and reveal the existence of a 3 unknown kind of inflammatory white blood cell. the results are published in this week's early online edition of the 4 of the national academy of sciences.

in all types of 5 diseases, healthy, functioning tissues are progressively replaced by fibrous scarring, which renders the tissues or larger organ increasingly dysfunctional until, eventually, it fails. the process is called fibrosis. in the human liver, the end result is cirrhosis, the 12th leading cause of death by disease in the united states with roughly 27,000 deaths 6. fibrosis occurs in other organs as well, such as the heart, kidneys and lungs, with comparable deadly effect.

scientists do not 7 understand the process of fibrosis, particularly how problematic fibroblast cells are created. for years, conventional wisdom has 8 that fibroblasts(纤维母细胞) are likely to be transformed epithelial cells, a 9 called "epithelial to mesenchymal transition" or emt. a protein called fibroblast-specific protein 1 (fsp1) has long been considered to be a reliable 10 of fibroblasts in injured organs undergoing tissue remodeling and has been broadly used to identify the presence of fibrotic disease.

the new research undermines the validity of 12(流行的,普遍的) assumptions about emt and fsp1, but also opens the door to new avenues of 13 that could ultimately lead to improved detection and treatment of cirrhosis and similar conditions.

"this work, along with earlier papers, puts into question a whole area of research – at least in terms of the liver" said david brenner, md, 14 15 for health sciences, dean of the uc san diego school of medicine and co-author of the paper. "the old evidence and assumptions about the source of fibroblasts and the role of fsp1 as a marker are not 11."

specifically, in experiments using cell cultures, human liver samples and mouse models, the researchers found no evidence of emt – that transformed epithelial cells became liver fibroblasts. rather, endogenous stellate cells appear to be the culprit(犯人,罪犯) , though the scientists note many types of cells seem to contribute, directly or 16, to liver fibrosis.

likewise, experiments proved fsp1 to be an unreliable marker for fibrosis. cells containing fsp1 increased in human and experimental liver disease and in liver cancer, but researchers found that liver fibroblasts do not express the protein, nor do hepatic stellate cells – a major cell type involved in liver fibrosis. similarly, fsp1 was 17 not to be a marker for myofibroblasts (a fibroblast with some properties of a smooth muscle cell) or any 18 of myofibroblasts(细胞) .

"there have been hundreds of papers based on fsp1 as a marker," said brenner. "that thinking now seems to have been a mistake. one of the take-home messages of this paper is that fsp1 clearly can't be reliably used as a marker."

on the other hand, the scientists discovered that fsp1 is a consistent marker for a previously unknown subset of inflammatory white blood cells or macrophages(巨噬细胞) found in injured livers. the protein appears to also perform biological functions in the macrophages, though these remain to be determined.

"it's a whole new class of monocytes," said brenner. "we don't know what they do, but they're worth investigating."



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1 yxsxf     
adj.确切的,权威性的;最后的,决定性的
参考例句:
  • this book is the definitive guide to world cuisine.这本书是世界美食的权威指南。
  • no one has come up with a definitive answer as to why this should be so.至于为什么该这样,还没有人给出明确的答复。
2 2hczgo     
n.持续,地位;adj.永久的,不动的,直立的,不流动的
参考例句:
  • after the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
  • they're standing out against any change in the law.他们坚决反对对法律做任何修改。
3 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 wk2zvx     
n.进程,过程,议程;诉讼(程序);公报
参考例句:
  • he was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
5 bo9zl     
adj.(疾病)长期未愈的,慢性的;极坏的
参考例句:
  • famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
  • chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。
6 vzyzno     
adv.一年一次,每年
参考例句:
  • many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
  • they celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。
7 gfuzd     
adv.完全地,全部地,彻底地;充分地
参考例句:
  • the doctor asked me to breathe in,then to breathe out fully.医生让我先吸气,然后全部呼出。
  • they soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。
8 5143cf6a131d14610f5f8561619aae61     
v.假定,设想,假设( posit的过去式和过去分词 )
参考例句:
  • several writers have posited the idea of a universal consciousness. 有几个作者都假设存在普遍意识。 来自辞典例句
  • all cash receipts should be recorded and de-posited daily. 所有的现金收据应该被每日记录和存放。 来自互联网
9 uzpyi     
n.转化,转换,转变
参考例句:
  • he underwent quite a conversion.他彻底变了。
  • waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。
10 i8nxm     
n.指标;指示物,指示者;指示器
参考例句:
  • gold prices are often seen as an indicator of inflation.黃金价格常常被看作是通货膨胀的指标。
  • his left-hand indicator is flashing.他左手边的转向灯正在闪亮。
11 eicwm     
adj.有确实根据的;有效的;正当的,合法的
参考例句:
  • his claim to own the house is valid.他主张对此屋的所有权有效。
  • do you have valid reasons for your absence?你的缺席有正当理由吗?
12 e1ozf     
adj.盛行的;占优势的;主要的
参考例句:
  • she wears a fashionable hair style prevailing in the city.她的发型是这个城市流行的款式。
  • this reflects attitudes and values prevailing in society.这反映了社会上盛行的态度和价值观。
13 mrkzq     
n.调查,调查研究
参考例句:
  • in an investigation,a new fact became known, which told against him.在调查中新发现了一件对他不利的事实。
  • he drew the conclusion by building on his own investigation.他根据自己的调查研究作出结论。
14 nu0zq     
n.坏事;恶习;[pl.]台钳,老虎钳;adj.副的
参考例句:
  • he guarded himself against vice.他避免染上坏习惯。
  • they are sunk in the depth of vice.他们堕入了罪恶的深渊。
15 auaya     
n.(英)大臣;法官;(德、奥)总理;大学校长
参考例句:
  • they submitted their reports to the chancellor yesterday.他们昨天向财政大臣递交了报告。
  • he was regarded as the most successful chancellor of modern times.他被认为是现代最成功的财政大臣。
16 a8uxr     
adv.间接地,不直接了当地
参考例句:
  • i heard the news indirectly.这消息我是间接听来的。
  • they were approached indirectly through an intermediary.通过一位中间人,他们进行了间接接触。
17 duszmp     
adj.坚定的;有决心的
参考例句:
  • i have determined on going to tibet after graduation.我已决定毕业后去西藏。
  • he determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
18 5e19fce64ab14f5a4b5c8687640c2593     
n.先驱( precursor的名词复数 );先行者;先兆;初期形式
参考例句:
  • phenyl (or polyphenyl) substituted epoxides serve as excellent precursors to phenyl (or diphenyl) carbenes. 某些苯代(或多苯)环氧乙烷是制取带苯环(或二苯)碳烯的极好原料。 来自辞典例句
  • note the presence of megakaryocytes, erythroid islands, and granulocytic precursors. 可见巨核细胞,红细胞岛和粒细胞前体细胞。 来自互联网
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