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Destabilization of lens protein conformation by glutathione mixed disulfide   总被引:1,自引:0,他引:1  
Mixed disulfide between lens crystallin and glutathione has been observed in human cataracts and could be formed in vitro by thiol-disulfide exchange reaction. The glutathionyl crystallins have been reported to become partially unfolded. The present paper reports the conformational destabilization by the mixed disulfide formation in calf alpha- and gamma-II crystallin. The conformational stability was studied by the denaturants urea and guanidine hydrochloride (Gdn-HCl), and by proteolytic degradation. The denaturation curves of both urea and Gdn-HCl shift to lower denaturant concentration for crystallins of glutathione mixed disulfide. The decrease in conformational stability is estimated to be 0.22- and 0.92 kcal mol-1 for modified alpha- and gamma-II crystallin, respectively. Proteolytic digestion also shows a faster rate of degradation for the modified crystallins. These results indicate that mixed disulfide destabilizes the crystallin conformation. The destabilization may make crystallins more susceptible to changes as observed in aging lenses.  相似文献   
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本文对从事京剧打击乐的55人(110耳)进行了听力调查及动态观察。利用图表进行对比分析,发现110耳中高频听力损伤89耳,占81%;语频听力损伤32耳,占29.1%;其中伴有高频耳鸣78耳,占70.9%。动态观察30人(60耳),均为永久性听阈阈移。高频听力损伤最早出现的频率是4kHz,并见典型“V”谷,符合噪声性聋的诊断。  相似文献   
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The Studies of Left Ventricular Dysfunction (SOLVD) trials were designed to evaluate the effects of enalapril on long-term mortality in patients with severe left ventricular (LV) dysfunction. Patients with LV ejection fractions less than or equal to 0.35 and symptoms of congestive heart failure (CHF) were enrolled in the treatment trial, whereas those with no history of overt CHF and taking no treatment directed for LV dysfunction were enrolled in the prevention trial. The baseline clinical characteristics of SOLVD patients were compared to characterize differences between patients in these 2 separate but concurrent trials. From over 70,000 patients screened with LV dysfunction, 4,228 patients were enrolled in the prevention trial and 2,569 patients in the treatment trial. Ischemic heart disease was the primary cause of LV dysfunction in both prevention (83%) and treatment (71%) trial patients. Prior myocardial infarction was present in 80% of the prevention and 66% of the treatment trial patients (p less than 0.001). In the prevention trial, infarction was recent (less than or equal to 6 months) in 27% patients and remote (greater than 6 months) in 57% patients. Treatment trial patients had proportionately more women (20 vs 13%; p less than 0.001) and non-Caucasians (20 vs 14%; p less than 0.001), as well as the coexisting risk factors of hypertension (42 vs 37%; p less than 0.001) and diabetes (26 vs 15%; p less than 0.001) than did prevention trial patients. Clinical characteristics of patients in both trials were influenced by the gender and race of enrolled patients. Similarly, coronary artery bypass surgery was performed less often in women and non-Caucasians.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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目的探讨胃黏膜内pH值对胆源性胰腺炎病情预后评估及在决定手术冶疗中应用的价值。方法对确诊的146例胆源性胰腺炎患者经鼻插入胃黏膜二氧化碳张力计(TRIP-NGS导管)测定胃黏膜内pH值,每隔12小时测定一次,并进行APACHEⅡ评分,将2组数据与外科治疗进行相关分析。结果①pH值变化反映胆源性胰腺炎病情发展变化,与器官衰竭数呈负相关;②外科干预治疗与内科治疗比较差异有统计学意义(P〈0.05);③pHI〉7.25与pH〈7.25患者开腹手术病死率和细菌培养阳性率比较差异有统计学意义(P〈0.05)。结论pH值对胆源性胰腺炎外科治疗有指导意义。外科处理原则是:①胆道无梗阻,以内科保守治疗为主;②伴胆道梗阻,先行经内镜十二指肠乳头括约肌切开术、经内镜鼻胆管引流术、B超导引引流、腹腔灌洗等,如胆道引流不畅或pH值持续下降,则开腹手术。  相似文献   
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The cytoplasm of human bile ductule epithelia was found to be Type V collagen positive, demonstrating that the epithelia were able to generate this type of collagen. The ductules proliferated greatly with Type V collagen positive cytoplasm in piece-meal necrosis of chronic active hepatitis (CAH). The capillary-like bile ductules inside human hepatic lobules were identified. Our findings might explain the mechanism of fibroplasia in CAH.  相似文献   
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