泛素-蛋白酶体系统及其与肝病关系的研究现状

泛素-蛋白酶体系统（UPS）主要由泛素、泛素活化酶、泛素结合酶、泛素连接酶、26S蛋白酶体及去泛素化酶等组成,是降解细胞内蛋白质的非溶酶体途径。UPS与多种疾病的发生发展有关,在肝病研究中也具有重要的病理生理意义。本文就UPS及其与肝病关系的研究现状作一综述。     

硫化氢与胃肠道疾病关系的研究进展

硫化氢(H2S)是目前发现的第三种具有生物学效应的气体信号分子,最新研究表明它与多种胃肠道疾病如肠易激综合征(IBS)、非甾体抗炎药(NSAID)所致的急性胃黏膜损伤、溃疡性结肠炎(UC)及直、结肠癌的发病有关。相关药物的研发与临床应用可能为这些疾病的治疗提供新的方向。     

脂连素与几种消化系病关系的研究近况

脂连素是重要的具有保护作用的细胞因子.本文对脂连素与几种消化系病(急性肝损伤、脂肪肝、肝纤维化、胃肠肿瘤)关系等方面的进展作一综述.     

高级糖基化终末产物的合成及其与疾病的关系

高级糖基化终末产物(advanced glycation end products,AGEs)是由蛋白或者脂质暴露于还原糖中而形成的一组复杂且具有异质性的物质.该物质可通过内源性或外源性途径形成,大体可分为6种.AGEs可在不同种类的细胞内累积,影响细胞内及细胞外的结构和功能,同时它还可以通过和细胞表面的受体作用,通过信号传导,引发一系列的病理生理过程.AGEs沉积在细胞内,影响细胞功能,导致糖尿病血管并发症的发生.AGEs还与各种肿瘤的生物学特性相关,它可以修饰热休克蛋白27或者与AGEs受体相结合来影响肿瘤细胞的生长和浸润.AGEs的抑制物,如OPB-9195,可抑制这一系列病理生理过程.     

Chemokine receptors and their role in inflammation and infectious diseases

Chemokines are small peptides that are potent activators and chemoattractants for leukocyte subpopulations and some nonhemopoietic cells. Their actions are mediated by a family of 7-transmembrane G-protein-coupled receptors, the size of which has grown considerably in recent years and now includes 18 members. Chemokine receptor expression on different cell types and their binding and response to specific chemokines are highly variable. Significant advances have been made in understanding the regulation of chemokine receptor expression and the intracellular signaling mechanisms used in bringing about cell activation. Chemokine receptors have also recently been implicated in several disease states including allergy, psoriasis, atherosclerosis, and malaria. However, most fascinating has been the observation that some of these receptors are used by human immunodeficiency virus type 1 in gaining entry into permissive cells. This review will discuss structural and functional aspects of chemokine receptor biology and will consider the roles these receptors play in inflammation and in infectious diseases.     

血清胶原酶对判断慢性乙型肝炎肝纤维化及炎症程度的意义

目的观察慢性乙型肝炎患者血清基质金属蛋白酶(MMPs)及金属蛋白酶组织抑制因子(TIMPs)水平与肝纤维化及炎症程度的相关性,寻找新的判定肝纤维化程度的血清学指标.方法慢性乙型肝炎患者88例,间隔半年行两次肝穿刺活检,病理组织进行炎症活动度及纤维化程度半定量计分;检测血清TIMP1、TIMP2、MMP1、MMP2、MMP9、Ⅳ型胶原、层黏连蛋白、Ⅲ型前胶原N端肽、透明质酸水平.结果血清TIMP1(r=0.540,P＜0.001)、MMP2(r=0.314,P=0.003)、TIMP1/MMP1(r=0.269,P＜0.001)与纤维化分级成正相关,MMP1与纤维化分级成负相关(r=-0.49 5,P＜0.001),且与血清Ⅲ型前胶原N端肽、透明质酸相关;根据受试者工作特性曲线(ROC)下面积计算,MMP1以13.96(ng/ml)为临界值,判别S2及S2以上纤维化的敏感性为90.5%,特异性为52.0%;TIMP1以76.84(ng/ml)为临界值,敏感性为91.6%,特异性为64.0%.MMP1以6.86(ng/ml)为临界值,判别肝硬化(S4)期敏感性为70.7%,特异性为80.9%;TIMP1以210.04(ng/ml)为临界值,其敏感性60.5%,特异性92.3%.MMP1、TIMP1与炎症分级及计分均有相关性,而TIMP1与碎屑坏死、桥接坏死相关性最好(r=0.435,P＜0.001),TIMP2与MMP9与炎症没有明显相关性.结论血清TIMP1、MMP1、MMP2水平、TIMP1/MMP1比值可作评估肝纤维化发展或减轻的指标.     

Intestinal permeability in patients with chronic liver diseases: Its relationship with the aetiology and the entity of liver damage

BackgroundAlteration in intestinal permeability may be an important factor in the pathogenesis of both the progression of some chronic liver diseases and the onset of some complications in patients with liver cirrhosis.AimsTo investigate the relationships between intestinal permeability, portal hypertension, alcohol use, plasma levels of pro-inflammatory cytokines, and nitric oxide, expressed as s-nitrosothiols, and nitrite levels in patients with various types and degrees of chronic liver diseases.Methods134 healthy volunteers and 83 patients with chronic liver damage entered the study. Intestinal permeability was assessed with the lactulose/mannitol test. Plasma levels of tumour necrosis factor-alpha, interleukin-6, and nitrite and total s-nitrosothiols were determined.ResultsIntestinal permeability was altered in patients with advanced liver disease and impaired in 15–35% of patients without cirrhosis. Independent factors for intestinal permeability alteration were age, portal hypertension, alcohol use, and diabetes. Plasma levels of inflammatory cytokines and nitrosothiols were significantly higher in patients with altered intestinal permeability.ConclusionsAn intestinal permeability evaluation in patients with chronic liver diseases might clarify the significance of intestinal permeability in the pathophysiology of both the progression of liver damage, and the occurrence of complications that accompany liver cirrhosis.     

Sexual dysfunctions and their treatment in liver diseases

Sexual dysfunction (SD) is a prevalent but very commonly ignored aspect in the treatment of liver diseases and cirrhosis. The etiology of SD is multifactorial and therefore treatment strategies are complex, especially in females. Phosphodiesterase inhibitors are useful and effective in erectile dysfunction in males but in females, no single drug is available for SD, therefore multimodal treatment is required depending upon the cause. The foremost and fundamental requirement in both genders is to be stress-free and have adequate control of liver diseases. Improved quality of life is helpful in improving SD and vice versa is also true. Therefore, patients suffering from liver diseases should come forward and ask for treatment for SD, and physicians should actively enquire about SD while history taking and evaluating these patients. SD results in deterioration of quality of life, and both are modifiable and treatable aspects of liver diseases, which are never addressed actively, due to social taboos and fears of SD treatment in the presence of liver diseases. The diagnosis of SD does not require costly investigations, as the diagnosis can be established based on validated questionnaires available for both genders, therefore detailed targeted history taking using questionnaires is essential. Data are emerging in this area but is still at an early stage. More studies should be dedicated to SD in liver diseases.