蛋白尿发生的分子遗传学机制

蛋白尿是儿科肾脏疾病常见症状 ,当尿蛋白水平 >5 0mg/ (kg·d) ,同时伴低清蛋白血症、水肿及高脂血症时诊断为肾病综合征 ,其中大量蛋白尿是其最关键的表现。蛋白尿发生主要与肾小球滤过屏障有关 ,长期以来人们围绕肾小球滤过屏障的电荷屏障及有关分子进行较多的研究 ,但蛋白尿发生的分子机制一直不明确。近 5年来 ,国外通过研究先天性及遗传性肾病新认识 ,许多与蛋白尿发生、发展相关的基因及其编码的蛋白 ,为研究蛋白尿发生机制开辟新的途径。本文通过复习各种与遗传有关、以蛋白尿为主要表现的疾病介绍其相关的致病分子 ,有助于理解蛋白…     

蛋白尿的发生机制研究进展

蛋白尿的主要发生机制是肾小球滤过增加和（或）肾小管重吸收障碍。近年来,对肾小球滤过屏障研究取得显著进展,内皮细胞表层和足细胞下间隙成为肾小球滤过屏障新组分,发现越来越多的足细胞分子与蛋白尿关系密切,主导或者参与了肾小球疾病的发生。     

以低分子质量蛋白尿为主要表现的遗传性肾小管疾病

遗传性肾小管疾病隐匿起病,缺乏特异性临床表现,极易漏诊、误诊.其中有相当一部分患者将进展至终末期肾病.现通过介绍几种以低分子质量蛋白尿为主要特点的遗传性肾小管疾病,以提高对此类疾病的认识,避免不必要的治疗.     

Legg-Calve-Perthes Disease发病机制的分子遗传学研究新进展

Legg-Calve-Perthes Disease（简称LCPD）是1910年Legg（美国）、Calve（法国）、Perthes（德国）各自发现并描述的儿童股骨头骨骺坏死。随着对本病的深入研究，发现其可能与创伤、一过性滑膜炎、生长发育异常、内分泌失调、自身免疫缺陷、遗传、环境等多种因素有关，但确切的病因及发病机制至今不是完全明了，目前普遍认同的LCPD发病机制是血液循环障碍学说。     

CD4+CD25+调节性T细胞在免疫性血小板减少性紫癜发病机制中的作用

免疫性血小板减少性紫癜是一种以血小板破坏增加和(或)血小板生成异常为特点自身免疫性疾病,以皮肤、黏膜或内脏出血为主要表现.该病发病机制复杂,目前尚未明确.CD4+ CD25+调节性T细胞为抑制细胞,是具有独特免疫调节功能的成熟CD4+T细胞亚群,在小鼠和健康人体中约占外周血CD4+T细胞的5％ ～10％,占人体外周血单个核细胞的1％ ～2％,其通过多种途径对免疫反应发挥抑制效应,能维持内环境的稳定.CD4+ CD25+调节性T细胞功能紊乱或数目异常是导致自身免疫性疾病的重要因素之一,在免疫性血小板减少性紫癜的发生、发展中发挥重要的作用.该文对CD4+ CD25+调节性T细胞的特征和作用及其在免疫性血小板减少性紫癜发病中的作用的研究进展作一综述.     

静脉免疫球蛋白对新生儿脐带血淋巴细胞免疫抑制机制的研究

目的从脐带血单个核细胞(CBMC)和CD3^ T淋巴细胞膜表面CD25、CD45RA、CD45RO分子表达的角度,探讨静脉免疫球蛋白(IVIG)对新生儿免疫功能的抑制机制。方法利用IVIG和植物血凝素(PHA)不同组合对CBMC或CD3^ T淋巴细胞进行刺激培养,再利用四色免疫荧光抗体标记-流式细胞技术检测细胞表面CD25、CD45RA、CD45RO分子的表达情况。结果IVIG可以抑制PHA诱导的CBMC的活化,表现为CD25分子表达的明显抑制;并且随着CD25分子表达的抑制,CD4^ 细胞表面的CD45RO分子的表达也被抑制,阻止了CBMC中的CD4^ CD45RA^ 细胞向CD4^ CD45RO^ 细胞转换。IVIG也可以抑制PHA诱导的脐带血CD3^ T淋巴细胞CD25分子和CD45RO分子的表达,但这种抑制程度远远不如对CBMC作用明显。结论IVIG可以抑制脐带血T淋巴细胞的活化过程,这种抑制作用除了与IVIG对T淋巴细胞的直接作用外,还可能通过了其他免疫细胞或免疫分子的间接介导。IVIG对CD4^ CD45RO^ T淋巴细胞的抑制作用可能是IVIG抑制B淋巴细胞免疫球蛋白释放的重要机制之一。新生儿期应用IVIG有可能使免疫功能低下加重。     

低氧性肺动脉高压发生机制中气体信号分子的病理生理学意义

低氧性肺动脉高压(hypoxie pulmonary hyper-tension)是临床众多心肺疾病发生发展过程中重要的病理生理环节.低氧性肺血管结构重建是低氧性肺动脉高压的重要病理基础[1],其主要特征为肺动脉中膜平滑肌细胞增生、肥大,中膜增厚;非肌型动脉及部分肌型动脉肌化,形成肌型动脉以及血管壁中细胞外基质增多.低氧性肺血管收缩是肺动脉高压的始动环节和主要病理过程,后期以肺血管结构重建为主要病理生理改变.因此积极寻找低氧性肺动脉高压的发病机制,对引导其治疗有积极的推动作用.     

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??Proteinuria occurs mainly due to increased filtration of plasma proteins through glomerular capillary wall and/or incapability of renal tubular reabsorption of small molecular proteins. Significant advances have been made in study on glomerular filtration barrier in recent years. Now endothelial surface layer and subpodocyte space have been accepted as new layers of whole glomerular filtration barrier??and more and more podocyte molecules have been found to play a causative role or participate in the occurrence of proteinuria.     

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??Proteinuria??as an important clinical manifestation of kidney disease??is also an independent risk factor for the progression of renal disease. So the control of proteinuria has become an important target for diagnosis and treatment of kidney disease. Physiological proteinuria??which in the past is different from the pathological proteinuria??is considered to be a benign change. But in clinical practice??there is increasing evidence that some of the physiological proteinuria also has a poor prognosis. In this paper??we put forward the definition criterion of physiological proteinuria??and give the corresponding follow-up advice??in order to avoid the judgment of the simple benign change of physiological proteinuria.     

Hemangiomas: new insights and classification

Infantile hemangiomas are the most common tumors of infancy, but less common vascular tumors also can affect young infants and children. In most cases, the diagnosis of IH can be made clinically, but imaging studies and even biopsy may be required in less-than-typical cases. With a careful history and physical examination focusing on the timing, location, and type of hemangioma, as well as extracutaneous signs and symptoms, the general pediatrician will know when to be concerned about a high risk vascular tumor and proceed with referral or further evaluations.     

Renal cystic disease: new insights for the clinician

This article cannot comprehensively cover the enormous strides made in defining the molecular and cellular basis of renal cystic diseases over the last decade. Therefore, it provides a brief overview and categorization of inherited, developmental, and acquired renal cystic diseases, providing a relevant, up-to-date bibliography as well as a useful list of informative Internet Web sites. Its major focus is the translational biology of polycystic kidney disease. It demonstrates how emerging molecular and cellular knowledge of the pathophysiology of particular diseases such as autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ADPKD) can translate into innovative therapeutic insights.     

Shigella infections in children: new insights

Shigellosis , the acute enteric infection caused by bacteria of the genus Shigella , has a worldwide distribution with an estimated annual incidence of 164.7 million cases, of which 163.2 million occur in developing countries, and 1.1 million deaths. Sixty-nine percent of all episodes and 61 percent of all Shigella -related deaths involve children younger than 5 years old. In the United States, 10,000 to 15,000 cases of shigellosis are reported each year. Although usually confined to the colonic mucosa, shigellosis sometimes can cause extraintestinal complications. Recent publications have shed light on the clinical characteristics of Shigella -induced bacteremia, surgical complications, urogenital symptoms, and neurologic manifestations, and on the unique manifestations in the neonatal period. The mainstay of treatment of shigellosis in children is correction of the fluid and electrolyte loss, which often is achieved by the administration of oral rehydration solutions. Appropriate antibiotic therapy shortens the duration of both clinical symptoms and fecal excretion of the pathogen. However, the increasing antimicrobial resistance of shigellae worldwide constitutes a major problem. Regarding the pathophysiology of shigellosis and its complications, recent data not only elucidated the molecular mechanisms involved but also linked manifestations of disease to the interplay of bacterial virulence factors and host responses. The improved understanding of the pathophysiology is hoped to lead to innovative therapeutic approaches against shigellosis and new generations of vaccine candidates.