肝星状细胞的活化与肝纤维化

肝纤维化是机体对损伤的一种修复作用，即使可以应用基因或其他疗法彻底消除纤维化，但机体对抑制或消除纤维化后将产生何种反应及后果尚难预测。肝星状细胞（hepatic stellate cells，HSC）是引起肝纤维化的主要细胞，对HSC与其活化型一肌成纤维细胞（myofibroblast，MF）在肝损伤中作用的研究已颇为深入，而HSC激活在肝纤维化发生、发展中的作用甚为重要。     

肝星状细胞活化相关信号通路在肝纤维化中的研究进展

肝纤维化是多种慢性肝损伤造成的细胞外基质(extracellular matrix, ECM)过度累积及降解不足的病理结果,如不加以干预会逐渐进展为肝硬化,甚至肝细胞癌。肝星状细胞(hepatic stellate cell, HSC)是ECM的主要来源,并且HSC在肝纤维化的起始、发展和消退过程中发挥关键作用。近年来,HSC活化涉及的信号传导通路成为研究热点,本文总结了HSC活化过程中的重要信号通路。     

肝纤维化进程中细胞外基质对肝星状细胞的作用及机制研究进展*

肝纤维化是一种肝内弥漫性细胞外基质（ECM）过度沉积的病理过程,且肝星状细胞（HSC）的激活是肝纤维化发生发展的中心环节。本文主要介绍了在肝纤维化进程中ECM各种成分比例、分子结构的改变及其ECM分子空间结构改变对HSC的激活、增殖和凋亡的作用和机制。     

肝纤维化治疗研究进展

肝纤维化是肝脏对于慢性肝损伤的修复反应,以细胞外基质产生和沉积过多为特征。多种细胞参与了肝纤维化的发病过程,主要是星状细胞发挥重要的作用。肝纤维化持续进展是慢性肝病发展至肝硬化的关键。过去20年里对肝纤维化细胞和分子基础研究有了长足的进步,对纤维化治疗也有了新的认识和进展。本文重点介绍了病因治疗、中药治疗、基因治疗和干细胞治疗等进展。     

中药抗肝纤维化作用与诱导肝星状细胞凋亡机制研究概述

肝纤维化是指肝脏中细胞外基质尤其是胶原的过量沉积，是许多慢性肝病发展为肝硬化的共同病理过程。肝纤维化的发生，首先是有肝细胞的损伤，然后是肝损伤所致的肝星状细胞（hepatic stellate cell，HSC）的激活，两者关系密切，均为肝纤维化发生发展中的重要环节。目前，越来越多的学者认为肝星状细胞凋亡在肝纤维化的消退中扮演了重要角色。     

转化生长因子β-Smad信号通路与肝纤维化

肝纤维化是慢性肝损伤向肝硬化进展过程中的一个关键阶段,是一种可逆的过程,其形成是由于肝内多种细胞分泌的细胞因子和炎性介质综合作用于肝星状细胞（Hepatic stellate cell,HSC）,激活HSC致使细胞外基质（extracellular matrix,ECM）各成分合成增多而在肝内过度沉积引起的。     

丹酚酸B对大鼠肝星状细胞增殖周期的抑制作用

丹酚酸B(SAB)是丹参的主要水溶性成分，具有良好的抗D-半乳糖胺急性肝损伤和抗四氯化碳诱导的肝纤维化作用，还可抑制肝星状细胞(HSC)增殖及胶原合成，对脂质过氧化有很强的抑制作用，临床上已初步显示具有一定的抗肝纤维化作用。肝纤维化发生过程中，细胞外基质的主要来源是活化的HSC。我们试图在细胞增殖的整体水平上探讨SAB抗肝纤维化的作用机制。     

过氧化物酶体增殖物激活受体γ与肝星状细胞在肝纤维化中的关系

肝纤维化是慢性肝损伤后常见的形态学表现，大多数是由慢性肝脏疾病发展而来。而肝损伤（肝实质炎症、坏死）激活肝星状细胞（HSC）引起大量细胞外基质沉积，是肝纤维化发生机制的中心环节。在正常肝脏中，HSC处于静息状态，细胞质中脂滴丰富，具有合成和分泌少量细胞外基质和胶原酶的能力。在肝损伤及各种慢性肝病时，HSC被激活转化为肌成纤维母样细胞，发生明显的形态和结构变化：细胞质中脂滴减少或消失，增殖迁移活性明显增强，分泌多种细胞因子和黏附分子，合成各种细胞外基质（ECM）的能力明显增强，抑制基质金属蛋白酶（MMPs）的合成和分泌，而上调基质金属蛋白酶抑制剂（TIMPs）的表达，同时发生多种基因表达的改变。     

肝星状细胞活化的关键路径

肝星状细胞（HSC）为肝纤维发生发展中心环节,活化状态HSC的凋亡是纤维化的关键特征。HSC激活转变为肌成纤维细胞（MFC）表型,收缩、增生,分泌胶原蛋白和其他细胞外基质（ECM）参与肝内结构的重建,通过集成信号网络调节ECM的沉积从而促进纤维化或者修复损伤。肝纤维化进展和逆转都需要特定信号通路,了解其在肝损伤中如何互动和演变对揭示肝纤维发生发展的复杂机制尤为关键。     

血小板衍生生长因子及其新成员在肝纤维化发生机制中的作用

随着分子生物学技术的广泛应用，在肝纤维化研究领域不断取得新的进展。目前的研究已初步证实，肝星状细胞（hepatic stellate cells，HSC）激活是肝纤维化发生的基础和中心环节。PLT衍生生长因子（platelet-derived growth factor，PDGF）则在肝脏慢性损伤引起HSC激活、发生型的转变过程中起主要作用，尤其是对HSC的增殖和趋化作用。     

Biliary microlithiasis,sludge,crystals,microcrystallization,and usefulness of assessment of nucleation time

BACKGROUND:The process of microcrystallization,its sequel and the assessment of nucleation time is ignored.This systematic review aimed to highlight the importance of biliary microlithiasis,sludge,and crystals,and their association with gallstones,unexplained biliary pain,idiopathic pancreatitis, and sphincter of Oddi dysfunction.DATA SOURCES:Three reviewers performed a literature search of the PubMed database.Key words used were"biliary microlithiasis","biliary sludge","bile crystals","cholesterol crystallisation","bile microscopy","microcrystal formation of bile","cholesterol monohydrate crystals","nucleation time of cholesterol","gallstone formation","sphincter of Oddi dysfunction"and"idiopathic pancreatitis".Additional articles were sourced from references within the studies from the PubMed search.RESULTS:We found that biliary microcrystals account for almost all patients with gallstone disease,7%to 79%with idiopathic pancreatitis,83%with unexplained biliary pain, and 25%to 60%with altered biliary and pancreatic sphincter function.Overall,the detection of biliary microcrystals in gallstone disease has a sensitivity ranging from 55%to 87%and a specificity of 100%.In idiopathic pancreatitis,the presence of microcrystals ranges from 47%to 90%.A nucleation time less than 10 days in hepatic bile or ultra-filtered gallbladder bile has a specificity of 100%for cholesterol gallstone disease.CONCLUSIONS:Biliary crystals are associated with gallstone disease,idiopathic pancreatitis,sphincter of Oddi dysfunction, unexplained biliary pain,and post-cholecystectomy biliary pain.Pathways of cholesterol super-saturation,crystallisation, and gallstone formation have been described with scientificsupport.Bile microscopy is a useful method to detect microcrystals and the assessment of nucleation time is a good method of predicting the risk of cholesterol crystallisation.     

Antibacterial activity of cefpodoxime in comparison with cefixime,cefdinir, cefetamet,ceftibuten, loracarbef,cefprozil, BAY 3522, cefuroxime,cefaclor and cefadroxil

Summary The new oral cephalosporins cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten demonstrate enhanced activity against Enterobacteriaceae susceptible to the established compounds as well (e.g. cefuroxime, cefaclor, cefadroxil). In addition, cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten include in their spectrum species hitherto resistant to oral cephalosporins (Proteus vulgaris, Providencia spp.,Yersinia enterocolitica). Besides, the majority of these compounds demonstrate relevant activity (MIC₅₀ equal to or below 2 mg/l) againstEnterobacter spp.,Citrobacter freundii, Serratia spp. andMorganella morganii. Ceftibuten is the most potent oral cephalosporin against most of the Enterobacteriaceae. Non-fermentative bacilli (Acinetobacter spp.,Pseudomonas spp.) remain completely resistant to oral cephalosporins (except someAcinetobacter species against cefdinir andPseudomonas cepacia against ceftibuten). Antistaphylococcal activity for oral cephalosporins is highest for cefdinir followed by BAY 3522, cefprozil, cefuroxime and cefpodoxime. Loracarbef, cefaclor and cefadroxil are about equally active, while the other compounds are only weakly active (cefixime) or inactive (cefetamet, ceftibuten). Enterococci are insensitive to new generation oral cephalosporins as they have been to established compounds. The most active oral cephalosporins against hemolytic streptococci are cefdinir and cefprozil.Streptococcus pneumoniae, Streptococcus milleri andStreptococcus mitior are most susceptible to cefpodoxime, cefdinir, cefuroxime and BAY 3522. Penicillin resistant pneumococci have to be regarded as resistant to all oral cephalosporins. Fastidious pathogens likeHaemophilus spp.,Moraxella catarrhalis andNeisseria gonorrhoeae are more susceptible to cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten than to the other oral cephalosporins. The activity of oral cephalosporins is only weak againstListeria spp.,Helicobacter pylori and anaerobic pathogens (except BAY 3522).Bordetella pertussis remains resistant to all absorbable cephalosporins. Progress in antibacterial activity of oral cephalosporins was mainly achieved by cefpodoxime, cefixime, cefdinir, cefetamet and ceftibuten against Enterobacteriaceae and the fastidious pathogens and against staphylococci and the nonenterococcal streptococci by cefdinir, BAY 3522, cefprozil and cefpodoxime.

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Antibakterielle Aktivität von Cefpodoxim im Vergleich mit anderen oralen Cephalosporinen

Zusammenfassung Die neuen oralen Cephalosporine Cefpodoxim, Cefixim, Cefdinir, Cefetamet und Ceftibuten zeigen eine verstärkte Aktivität auch gegen solche Enterobacteriaceae, die gegen etablierte Substanzen empfindlich sind (z.B. Cefuroxim, Cefaclor, Cefadroxil). Zusätzlich schließt das Spektrum von Cefpodoxim, Cefixim, Cefdinir, Cefetamet und Ceftibuten Spezies ein, die gegen die bisherigen oralen Cephalosporine resistent waren (Proteus vulgaris, Providencia spp.,Yersinia enterocolitica). Daneben zeigt die Mehrheit der neuen Substanzen erhöhte Aktivität (MHK₅₀<2 mg/l) gegenEnterobacter spp.,Citrobacter freundii, Serratia spp. undMorganella morganii. Gegen die meisten Enterobacteriaceae ist Ceftibuten das wirksamste orale Cephalosporin. Non-Fermenter (Acinetobacter spp.,Pseudomonas spp.) bleiben gegenüber oralen Cephalosporinen vollständig resistent (mit Ausnahme einigerAcinetobacter-Spezies gegen Cefdinir undPseudomonas cepacia gegen Ceftibuten). Die Antistaphylokokken-Aktivität oraler Cephalosporine ist am höchsten bei Cefdinir, gefolgt von BAY 3522, Cefprozil, Cefuroxim und Cefpodoxim. Loracarbef, Cefaclor und Cefadroxil sind etwa gleich aktiv, während die anderen Substanzen nur schwach aktiv (Cefixim) oder inaktiv sind (Cefetamet, Ceftibuten). Enterokokken sind gegenüber der neuen Generation oraler Cephalosporine ebenso unempfindlich wie gegenüber den etablierten Substanzen. Die aktivsten oralen Cephalosporine gegen hämolysierende Streptokokken sind Cefdinir und Cefprozil.Streptococcus pneumoniae, Streptococcus milleri undStreptococcus mitior sind am empfindlichsten gegen Cefpodoxim, Cefdinir, Cefuroxim und BAY 3522. Penicillin-resistente Pneumokokken müssen als resistent gegenüber allen oralen Cephalosporinen betrachtet werden. Anspruchsvolle Erreger wieHaemophilus spp.,Moraxella catarrhalis undNeisseria gonorrhoeae sind gegen Cefpodoxim, Cefixim, Cefdinir, Cefetamet und Ceftibuten empfindlicher als gegen die anderen oralen Cephalosporine. Die Aktivität oraler Cephalosporine gegenListeria spp.,Helicobacter pylori und Anaerobier (Ausnahme BAY 3522) ist nur schwach.Bordetella pertussis bleibt gegen alle resorbierbaren Cephalosporine resistent. Der Fortschritt in der antibakteriellen Aktivität oraler Cephalosporine wurde gegen Enterobacteriaceae und anspruchsvolle Erreger hauptsächlich durch Cefpodoxim, Cefixim, Cefdinir, Cefetamet und Ceftibuten erlangt, gegen Staphylokokken und Streptokokken (außer Enterokokken) durch Cefdinir, BAY 3522, Cefprozil und Cefpodoxim.

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Supported by Luitpold-Werk, a company of the Sankyo group.     

Electrochemical Recovery and Behaviors of Rare Earth (La,Ce, Pr,Nd, Sm,Eu, Gd,Tb, Dy,Ho, Er,Tm, and Yb) Ions on Ni Sheets

The electrochemical behaviors of rare earth (RE) ions have extensively been studied because of their high potential applications to the reprocessing of used nuclear fuels and RE-containing materials. In the present study, we fully investigated the electrochemical behaviors of RE(III) (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) ions over a Ni sheet electrode in 0.1 M NaClO₄ electrolyte solution by cyclic voltammetry between +0.5 and −1.5 V (vs. Ag/AgCl). Amperometry electrodeposition experiments were performed between −1.2 and −0.9 V to recover RE elements over the Ni sheet. The successfully RE-recovered Ni sheets were fully characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The newly reported recovery data for RE(III) ions over a metal electrode provide valuable information on the development of the treatment methods of RE elements.     

Clinical trials update: highlights of the scientific sessions of The American College of Cardiology 2002: LIFE,DANAMI 2, MADIT-2, MIRACLE-ICD,OVERTURE, OCTAVE,ENABLE 1 & 2, CHRISTMAS,AFFIRM, RACE,WIZARD, AZACS,REMATCH, BNP trial and HARDBALL

This article continues a series of reports updating recent research developments of particular interest to personnel involved in the treatment and management of patients with heart failure. This is a summary of selected presentations made at the American College of Cardiology 51st Annual Scientific Session held in Atlanta on 17-20 March 2002. Reports of the following clinical studies are included: LIFE, DANAMI 2, MADIT-2, MIRACLE-ICD, OVERTURE, OCTAVE, ENABLE 1 & 2, CHRISTMAS, AFFIRM, RACE, WIZARD, AZACS, REMATCH, BNP trial and HARDBALL.