Sex Disparities in Risk of Mortality Among Children With ESRD

1. Download high-res image (377KB)
2. Download full-size image

     

Genetic toxicity assessment using liver cell models: past,present, and future

ABSTRACT

Genotoxic compounds may be detoxified to non-genotoxic metabolites while many pro-carcinogens require metabolic activation to exert their genotoxicity in vivo. Standard genotoxicity assays were developed and utilized for risk assessment for over 40 years. Most of these assays are conducted in metabolically incompetent rodent or human cell lines. Deficient in normal metabolism and relying on exogenous metabolic activation systems, the current in vitro genotoxicity assays often have yielded high false positive rates, which trigger unnecessary and costly in vivo studies. Metabolically active cells such as hepatocytes have been recognized as a promising cell model in predicting genotoxicity of carcinogens in vivo. In recent years, significant advances in tissue culture and biological technologies provided new opportunities for using hepatocytes in genetic toxicology. This review encompasses published studies (both in vitro and in vivo) using hepatocytes for genotoxicity assessment. Findings from both standard and newly developed genotoxicity assays are summarized. Various liver cell models used for genotoxicity assessment are described, including the potential application of advanced liver cell models such as 3D spheroids, organoids, and engineered hepatocytes. An integrated strategy, that includes the use of human-based cells with enhanced biological relevance and throughput, and applying the quantitative analysis of data, may provide an approach for future genotoxicity risk assessment.     

肾综合征出血热发病机制研究进展

肾综合征出血热发病机制至今仍未完全阐明,病毒、病毒受体、细胞因子、自由基、特异性CTL反应、HLA差异性均可能与发病有关.此文对近年来的研究进展进行了综述.     

慢性肾衰竭急性加重的临床特征及相关因素分析

目的：探讨慢性肾衰竭（CRF）急性加重因素及其治疗措施对预后的影响。方法：对2001年1月～2005年6月住院治疗的CRF急性加重患者42例，按其加重原因、基础疾病、治疗方式和疗效进行回顾性总结。结果：CRF急性加重因素依次为各种感染（45．2％）、原发病加重（19．0％）、高血压未控制（14．3％）、水电解质紊乱（11．9％）、肾毒性药物（11．9％）、心功能不全（9．5％）、尿路梗阻（4．8％）、血高粘滞状态（2．4%），7例同时存在≥2种上述病因（16．7％）。CRF急性加重原发病以慢性肾小球肾炎（52．4％）和糖尿病肾病（11．9％）为主。积极治疗后肾功能恢复达到或接近原来水平者40例，死亡2例，死亡2例的年龄均在60岁以上。结论：对于CRF肾功能急剧恶化的患者，应积极寻找其加重因素，并采取非透析和透析相结合治疗，改善肾功能，降低病死率，延长患者生命。     

Functional mechanism underlying cyclooxygenase-2 expression in rat small intestine following administration of indomethacin: Relation to intestinal hypermotility

Background and Aim:  We recently reported that cyclooxygenase (COX)-2 is upregulated in the rat small intestine after administration of indomethacin, and this may be the key to non-steroidal anti-inflammatory drug (NSAID)-induced intestinal damage. The present study investigated the mechanism for COX-2 expression induced in the rat small intestine by indomethacin, in relation with ulcerogenic processes.
Methods:  Animals were given indomethacin or SC-560 p.o., and the intestinal mucosa was examined 24 h later.
Results:  Indomethacin caused hemorrhagic lesions in the small intestine, accompanied with an increase in intestinal motility, bacterial invasion and inducible nitric oxide synthase (iNOS) activity, as well as the expression of COX-2 mRNA in the mucosa. Although SC-560 did not cause any damage, this agent caused intestinal hypermotility, the bacterial invasion and the upregulation of COX-2 expression. The mucosal PGE₂ content was decreased by SC-560 at 3 h but recovered 12 h later, and this recovery of PGE₂ was attenuated by both atropine and ampicillin, in addition to rofecoxib. The intestinal hypermotility response to indomethacin was prevented by both 16,16-dimethyl PGE₂ and atropine, but not ampicillin. Yet all these agents inhibited not only the bacterial invasion but also the expression of COX-2 and iNOS activity in the intestinal mucosa following indomethacin treatment, resulting in the prevention of intestinal lesions.
Conclusion:  These results suggest that COX-2 expression in the intestinal mucosa following the administration of indomethacin is associated with intestinal hypermotility and bacterial invasion. The intestinal hypermotility caused by COX-1 inhibition may be a key to COX-2 expression after administration of NSAIDs and their intestinal ulcerogenic properties.     

糖化血红蛋白及糖化血清蛋白与糖尿病肾功能衰竭患者的血糖监测

糖化血红蛋白(Hb)A1c是血糖监测的苇要指标,反映检测前2～3个月的平均血糖水平.慢性肾功能衰竭(CRF)患者存在贫血、酸中毒、氧化应激、胰岛素抵抗、血液透析及促红细胞生成素(EPO)的应用等因素,对HbA1c的测定会造成影响.糖化血清蛋白(GSP)反映检测前2～3周的平均血糖水平,仅受血浆蛋白的影响,几乎不受血红蛋白和EPO治疗等以上因素的影响,且对短时间内的血糖变化更为敏感.将GSP作为糖尿病肾功能衰竭患者血糖监测指标可能比HbA1c更理想.     

肾综合征出血热患者T细胞亚群数量与白细胞介素2,4水平变化的关系

采用ABC免疫组化染色法及单克隆抗体夹心法ELISA，同步检测了34例肾综合征出血热（HFRS）患者外周血T细胞亚群数量和血清白细胞介素2和4（IL－2、IL－4）水平。发现HFRS病程中各T细胞亚群数量均有不同程度的升高，其中CDS阳性T细胞在各病期均有升高。IL－4水平升高仅见于发热期．而IL－2的升高主要在低血压期和少尿期。病程中有CD4／CD8比值的下降甚至倒置。这种比值的变化与IL－2和IL－4的动态变化有一定的相关性。结果揭示，在HFRS发病机理中存在Thl型和Th2型免疫反应等多种免疫病理机制。