大疱性表皮松解症患者为何遭受极端的疼痛
文章来源:未知 文章作者:enread 发布时间:2011-07-11 03:13 字体: [ ]  进入论坛
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For patients suffering from epidermolysis bullosa (EB大疱性表皮松解症), a hereditary1(遗传的) skin disease, even a gentle touch is extremely painful. Now Dr. Li-Yang Chiang, Dr. Kate Poole and Professor Gary R. Lewin of the Max Delbrück Center for Molecular2 Medicine (MDC) in Berlin-Buch have discovered the causes underlying3 this disease. Due to a genetic4 defect, individuals with EB cannot form laminin-332, a structural5 molecule6 of the skin that in healthy individuals inhibits7 the transduction(转导,转换) of tactile8 stimuli9 and neuronal branching (Nature Neuroscience, doi: 10.1038/nn.2873)*. According to the findings of the MDC researchers, this explains why EB patients are more sensitive to touch and experience it as painful. Even the slightest touch causes a stinging sensation like being stabbed with pins; the body is covered with blisters10(水疱) and the skin is inflamed11 in many places. Young patients with epidermolysis bullosa are often called "butterfly children" because their skin is as fragile as a butterfly's wing. Because of the severe pain associated with the disease, EB sufferers hardly have any chance to lead a normal life. Even walking is a torment12(痛苦,苦恼) because of the pressure on the soles of the feet.

Due to a genetic defect, the patients' outer skin layer (epidermis) separates from the underlying skin layer (dermis), and blisters (bullosa) are formed. EB patients are deficient13 in laminin-332, a structural molecule normally found between the skin cells in the extracellular matrix which serves as a kind of cellular14 "glue" between the two skin layers.

The new findings of the MDC researchers show that in healthy individuals, laminin(层粘连蛋白) -332 has other important functions as well: It inhibits touch transduction and prevents the branching of the sensory15 neurons that are receptive to tactile(触觉的) stimuli in the skin.

At their endings, sensory neurons have mechanosensitive ion channels. These are proteins in the cell membrane16 through which charged particles can flow into the cell in a controlled manner. Upon touch, pressure on the extracellular matrix actuates a tether mechanism17 on the ion channels, thus opening the channels and allowing the charged particles to flow through. This excites the neuron, thus enabling the stimulus18 to be perceived.

Unsuppressed mechanotransduction

In experiments using cell cultures, the MDC researchers found that physical stimuli trigger ion currents in all neurons not surrounded by laminin-332. In neurons growing on laminin-332, by contrast, the number of responsive cells was much reduced. "To a great extent, laminin-332 blocks the tether(范围,栓绳) mechanism that opens the ion channels, thus impeding19(临近的) stimulus transduction. Because patients with epidermolysis bullosa are deficient in laminin-332, the transduction of the stimulus is unsuppressed. Their sensory neurons are excited much more strongly, and thus they react much more sensitively to mechanical stimuli," Professor Lewin explained.

Furthermore, in the skin tissue of EB patients the MDC researchers found that sensory neurons showed much more branching than in the skin of healthy individuals. "From cell-culture experiments we know that laminin-332 inhibits neuronal branching. Without laminin-332 this inhibition does not take place. Presumably, this effect also contributes to the increased perception of tactile stimuli," Professor Lewin said.

In further studies the researchers hope to find drug targets for therapy. However, much has already been achieved: "Because the causal mechanisms20 are now understood, we can focus on the patient's pain situation and on administering more efficient pain therapies," he added. "We recommend that in treating the disease, neurologists should be consulted in addition to dermatologists21(皮肤科医生) .



点击收听单词发音收听单词发音  

1 hereditary fQJzF     
adj.遗传的,遗传性的,可继承的,世袭的
参考例句:
  • The Queen of England is a hereditary ruler.英国女王是世袭的统治者。
  • In men,hair loss is hereditary.男性脱发属于遗传。
2 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。
3 underlying 5fyz8c     
adj.在下面的,含蓄的,潜在的
参考例句:
  • The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
  • This word has its underlying meaning.这个单词有它潜在的含义。
4 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
5 structural itXw5     
adj.构造的,组织的,建筑(用)的
参考例句:
  • The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
  • The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。
6 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。
7 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。
8 tactile bGkyv     
adj.触觉的,有触觉的,能触知的
参考例句:
  • Norris is an expert in the tactile and the tangible.诺里斯创作最精到之处便是,他描绘的人物使人看得见摸得着。
  • Tactile communication uses touch rather than sight or hearing.触觉交流,是用触摸感觉,而不是用看或听来感觉。
9 stimuli luBwM     
n.刺激(物)
参考例句:
  • It is necessary to curtail or alter normally coexisting stimuli.必需消除或改变正常时并存的刺激。
  • My sweat glands also respond to emotional stimuli.我的汗腺对情绪刺激也能产生反应。
10 blisters 8df7f04e28aff1a621b60569ee816a0f     
n.水疱( blister的名词复数 );水肿;气泡
参考例句:
  • My new shoes have made blisters on my heels. 我的新鞋把我的脚跟磨起泡了。 来自《现代汉英综合大词典》
  • His new shoes raised blisters on his feet. 他的新鞋把他的脚磨起了水疱。 来自《简明英汉词典》
11 inflamed KqEz2a     
adj.发炎的,红肿的v.(使)变红,发怒,过热( inflame的过去式和过去分词 )
参考例句:
  • His comments have inflamed teachers all over the country. 他的评论激怒了全国教师。
  • Her joints are severely inflamed. 她的关节严重发炎。 来自《简明英汉词典》
12 torment gJXzd     
n.折磨;令人痛苦的东西(人);vt.折磨;纠缠
参考例句:
  • He has never suffered the torment of rejection.他从未经受过遭人拒绝的痛苦。
  • Now nothing aggravates me more than when people torment each other.没有什么东西比人们的互相折磨更使我愤怒。
13 deficient Cmszv     
adj.不足的,不充份的,有缺陷的
参考例句:
  • The crops are suffering from deficient rain.庄稼因雨量不足而遭受损害。
  • I always have been deficient in selfconfidence and decision.我向来缺乏自信和果断。
14 cellular aU1yo     
adj.移动的;细胞的,由细胞组成的
参考例句:
  • She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
  • Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。
15 sensory Azlwe     
adj.知觉的,感觉的,知觉器官的
参考例句:
  • Human powers of sensory discrimination are limited.人类感官分辨能力有限。
  • The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。
16 membrane H7ez8     
n.薄膜,膜皮,羊皮纸
参考例句:
  • A vibrating membrane in the ear helps to convey sounds to the brain.耳膜的振动帮助声音传送到大脑。
  • A plastic membrane serves as selective diffusion barrier.一层塑料薄膜起着选择性渗透屏障的作用。
17 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。
18 stimulus 3huyO     
n.刺激,刺激物,促进因素,引起兴奋的事物
参考例句:
  • Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
  • Light is a stimulus to growth in plants.光是促进植物生长的一个因素。
19 impeding 8qtzd2     
a.(尤指坏事)即将发生的,临近的
参考例句:
  • Fallen rock is impeding the progress of rescue workers. 坠落的石头阻滞了救援人员的救援进程。
  • Is there sufficient room for the kiosk and kiosk traffic without impeding other user traffic? 该环境下是否有足够的空间来摆放信息亭?信息亭是否会妨碍交通或者行走? 来自About Face 3交互设计精髓
20 mechanisms d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
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。 来自《简明英汉词典》
  • He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
21 dermatologists 9d0b1366d0a189da771500d4b6c53665     
n.皮肤病学家( dermatologist的名词复数 )
参考例句:
  • Today dermatologists agree that the experiments were not conducted well. 今天,皮肤病学者承认,当时的实验操作上有误。 来自互联网
  • Dermatologists consistently recommend the low-cost old favorites, but of good-quality. 皮肤学家一致推荐物美价廉的老品牌。 来自互联网
TAG标签: skin disease patients
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