DNA拓扑异构酶I与肿瘤化疗

DNA拓扑异构酶 (topoisomerase ,TOPO )是一种基本的核酶 ,催化超螺旋结构的双链 DNA中某一条链的断裂和再接反应 ,从而改变 DNA的拓扑学状态 ,参与细胞DNA的复制和转录。TOPO 抑制剂是一类以 TOPO 为靶点的抗肿瘤药物 ,肿瘤细胞对 TOPO 抑制剂的耐药机制是复杂多样的 ,其中最主要的是 TOPO 基因突变和 TOPO 表达水平下降以及 TOPO 酶活性降低。笔者就近年来关于这方面的研究作一文献综述。1　 TOPO 及其抑制剂的作用机制人的 TOPO 是由 2 0号染色体上单拷贝基因编码的、分子量为 10 0 k Da的蛋白质。TOPO 催化 DN…     

腹膜透析相关性腹膜炎兔模型的病理形态学观察

用 12只新西兰大白兔分为腹膜炎组和对照组。腹膜炎组注射含活金黄色葡萄球菌的透析液 ,对照组为含生理盐水的透析液 ;观察腹膜透析相关性腹膜炎兔模型的病理变化。结果发现 :(1)腹膜炎组腹膜间皮细胞增生 ,水肿 ,血管扩张 ,炎症细胞浸润 ,对照组无变化。 (2 )腹膜炎组腹膜透液中葡萄糖浓度除 0min外 ,其他各时间点D/D0 葡萄糖均低于对照组 (P <0 .0 1)。 (3)腹膜炎组腹透液中肌酐浓度与血浆肌酐浓度比值 (D/Dcr)显著高于对照组中的浓度比值 (P <0 .0 5 )。 (4 )腹膜炎组透析液中WBC计数除O点外 ,其余各时间点明显高于对照组 (P <0 .0 5 )。提示新西兰兔腹膜注射含活金黄色葡萄球菌 48h后 ,进行腹膜透析时 ,其腹膜病理改变与临床腹膜透析并发腹膜炎特征基本一致     

大鼠原生殖细胞的形态学及分化特性

目的 研究大鼠胚胎原生殖细胞（Primordial germ cells, PGCs）的形态及其分化特性。方法 取受精后10.5 d的大鼠胚胎作HE染色,取受精后11.0~12.5 d的大鼠胚胎生殖嵴进行PGCs原代培养,光、电镜观察PGCs及其分化细胞的微细结构,碱性磷酸酶 (ALP) 染色检测细胞的分化程度。结果 大鼠PGCs位于卵黄囊内胚层深部的间充质内,体积大,呈椭圆形或不规则形;核大,染色质细密,含1~2个核仁。体外培养可见PGCs大而圆,散在分布,或聚集成团,胞质中含有椭圆形的线粒体和丰富的核糖体,ALP反应呈阳性;培养4~5 d,PGCs形态不规则,有伪足,ALP反应减弱,进一步分化可形成神经元样细胞、表皮细胞、心肌细胞、分泌细胞以及类似血管、心脏的管腔样结构等。由PGCs分化来的细胞ALP反应均呈阴性。结论 大鼠生殖嵴来源的PGCs是一种具有发育全能的、可分化形成3个胚层衍生物的胚胎多能干细胞。     

左右侧星状神经节阻滞对冠脉循环影响的实验研究

目的探讨左右侧星状神经节阻滞(SGB)对左冠状动脉急性闭塞区域的心肌组织血流及心肌血氧供需关系的影响.方法取犬24只,急性闭塞左冠状动脉前降支后,随机分为三组.对照组不进行SGB(6只);右侧SGB组(9只);左侧SGB组(9只),观察血液流变学有关指标变化.结果①左冠状动脉前降支闭塞后,心率(HR)、左冠状动脉回旋支血流量(CoBF)、左心室舒张期终末压(EDP)、心肌氧摄取率(MOER)显著增加(P＜0.05);闭塞区域心肌组织血流量(CBF)、心率血压双乘积(RPP)显著减少(P＜0.05);但三组间差异无显著性.②左SGB后HR、舒张期动脉血压(dBP)、CoBF、CBF无显著变化;左颈动脉血流量(LCaBF)、EDP、MOER、RPP与阻滞前相比有意义增加(P＜0.05).③右SGB后,EDP阻滞前后相比有意义增加(P＜0.05);HR、CoBF、RPP显著减少(P＜0.05).④HR、LCaBF、RPP、CoBF左右不同侧变化差异有显著性(P＜0.05).对照组左冠状动脉前下支闭塞后15min和30min各项测定指标没有显著性变化.结论急性左冠状动脉前降支闭塞导致的MOER、RPP的增加,左SGB无改善作用,并使其进一步增加;而右侧SGB后引起HR、CoBF、RPP显著减少.提示急性心肌梗塞时,左SGB有可能使心肌缺血、缺氧恶化,而右侧SGB在解除心脏疼痛的同时可减少心肌的耗氧量,因而有治疗作用.     

Efficacy of non-ablative fractional 1440-nm laser therapy for treatment of facial acne scars in patients with rosacea: a prospective,interventional study

Lasers in Medical Science - Acne scarring is one of the most common facial skin disorders. The appropriate treatments for acne scars in patients with rosacea have not been studied. This study was...     

Effect of Wuzi Yanzong Pills on Sertoli cells and blood–testis barrier in heat-stressed rats based on Akt signalling pathway

The blood–testis barrier (BTB) of Sertoli cells (SCs) is an important biological barrier that maintains spermatogenesis and provides a favourable microenvironment for spermatogenesis. However, heat stress can directly damage the BTB structural proteins of testicular SCs, leading to dyszoospermia. Wuzi Yanzong Pills (WYP) is a traditional Chinese medicine formula used to treat male reproductive diseases. However, whether WYP could ameliorate heat stress injury in primary SCs extracted from rat testes and BTB proteins remains unknown. Here, treatment with WYP (low, medium and high dose) increased the SC viability and the proliferation of cell antigen Ki67 significantly. Additionally, it promoted SC maturation, which presented in the form of increased androgen receptors (ARs) and decreased cytokeratin 18 (CK-18) in three WYP dose groups. WYP upregulated BTB proteins such as zonula occludens 1 (ZO-1) and occludin across all WYP groups and decreased phosphorylated Akt (p-Akt) in the middle and high-dose groups; however, ZO-1 and occludin recovery were reduced with the presence of Akt inhibitor in WYP groups. WYP improved SC viability and proliferation, and ameliorated dedifferentiation and BTB-proteins damaged by heat stress via Akt signalling. The findings present theoretical support for the effects of WYP in the management of dyszoospermia and male infertility.