人参皂苷的提取及总皂苷纯化工艺的研究进展

人参皂苷是人参重要的有效成分,研究显示人参皂苷具有广泛的药理作用,并可以作用于机体多个系统。人参皂苷的提取是进行人参皂苷活性研究的重要前提,现有多种提取工艺被应用,虽都能够获得人参皂苷,但也导致了人参皂苷质量标准的不同,这为人参皂苷药理活性的基础研究以及人参皂苷的临床应用设置了障碍。联合优化相关工艺发现高效便捷且质量标准统一的高纯度人参总皂苷提取工艺,能够保证人参皂苷相关研究物质基础的一致性,同时在临床应用相关药物时可以根据最佳工艺的原理改变剂型或改变药物处理方法增加药物疗效,逆向应用则可以补充完善药物质量控制手段。本文就近年来关于人参皂苷分离纯化工艺和方法作一综述,为发展优化人参总皂苷的分离纯化工艺提供理论依据和参考。     

生物反应器内再造组织工程化心肌的实验研究

目的：在体外模拟以微策略条件下构建心肌细胞-胶原复合体,探索组织工程化心肌组织体外再造的可行性。方法：采用顺序消化及差速贴壁法从1-2d龄新生大鼠的心肌组织中分离心肌细胞,并将其与多孔胶原复合形成复合体。复合体在旋转生物反应器（rotary cell culture system,RCCS）中进行培养,观测复合体内心肌细胞的生长状况、超微结构、细胞代谢率及细胞组分的变化,并将其与正常心肌和常规培养的复合体进行比较。结果：在RCCS中培养的复合体内的细胞具有心肌细胞的特殊超微结构,免疫组化显示其中的α-横纹肌肌动蛋白染色呈强阳性,与静止培养的复合体细胞相比,细胞代谢更加旺盛。结论：采用组织工程技术可以在RCCS中培育出组织工程化心肌组织。     

大肠癌患者外周血循环癌细胞检测的临床意义

目的探讨大肠癌外周血循环癌细胞检测的临床意义.方法以CK-20 mRNA为靶分子,RT-PCR技术检测3种癌细胞株(结肠腺癌细胞株SW-480、胃癌细胞株SGC-7901、食管癌细胞株TE-11)和67例大肠癌患者外周血细胞CK-20 mRNA的表达.结果三种癌细胞株中,只有结肠癌细胞表达CK-20 mRNA.RT-PCR技术能检出107个单核细胞中的一个肿瘤细胞;67例患者中,35例外周血CK-20 mRNA阳性,阳性率与大肠癌Dukse'分期明显相关:Dukes'A期25%,B期38.46%,C期55.17%,D期70.59%.53例手术治疗患者中,术前25例CK-20 mRNA阳性,术后30例阳性.25例术后早期短程化疗患者,化疗前阳性6例,化疗后仅2例阳性.结论大肠癌循环癌细胞(CK-20 mRNA)的检测可能成为判断大肠癌恶性程度、转移和复发以及疗效监测的客观指标.     

预防给药对大鼠硫化氢吸入中毒肺脂质过氧化和抗氧化系统的影响

本文观察了DMAP、NaNO_2、VE、地塞米松、山莨菪碱对大鼠H_2S吸入中毒所致的肺脂质过氧化和天然抗氧化系统改变的预防作用。测定了H_2S中毒后6、12h肺组织及支气管肺泡灌洗液中的MDA,肺SOD,GSH和VE的含量。结果表明,给药组MDA含量显著低于中毒组,其中DMAP,VE和NaNO_2等组的MDA含量与正常无差异(但BALF中VE组,NaNO_2组含量高于正常对照水平,P<0.01)。各组SOD活性增强,GSH、VE的含量增加。上述结果提示这些药物均能在不同程度上降低H_2S中毒时肺自由基的含量。从而减轻因自由基含量升高而引起的肺损伤。提示DMAP,VE,NaNO_2,地塞米松,山莨菪碱等药对大鼠H_2S吸入中毒有预防作用,其中以DMAP,VE,NaNO_2的效果相对较好。     

慢性肝炎血清Ⅳ型胶原和层粘连蛋白的水平及其临床意义

Serum levels of laminin and type IV collagen of 188 patients with different types of viral hepatitis were determined by RIA. Thirty-five blood donors were served as normal control. The results showed that: (1) higher levels of type IV collagen was found in patients with severe chronic hepatitis, post-hepatitis cirrhosis or subfulminant hepatitis; (2) the level of laminin was obviously increased in post-hepatitis cirrhosis and subfulminant hepatitis; (3) there was a positive correlation between the levels of type IV collagen and laminin as well as gamma globulin, and negatively correlated to serum albumin, no correlation with alanine aminotransferase was observed; (4) detecting rate of hepatic fibrosis was increased with combination of serum laminin and type IV collagen examination; (5) serum type IV collagen was more sensitive than that of serum laminin. The results suggest that determination of serum type IV collagen and laminin are useful in diagnosis of hepatic fibrosis, and combination of the two parameters is recommended.     

The in vitro preconditioning of myoblasts to enhance subsequent survival in an in vivo tissue engineering chamber model

The effects of in vitro preconditioning protocols on the ultimate survival of myoblasts implanted in an in vivo tissue engineering chamber were examined. In vitro testing: L6 myoblasts were preconditioned by heat (42 °C; 1.5 h); hypoxia (<8% O(2); 1.5 h); or nitric oxide donors: S-nitroso-N-acetylpenicillamine (SNAP, 200 μM, 1.5 h) or 1-[N-(2-aminoethyl)-N-(2-aminoethyl)amino]-diazen-1-ium-1,2-diolate (DETA-NONOate, 500 μM, 7 h). Following a rest phase preconditioned cells were exposed to 24 h hypoxia, and demonstrated minimal overall cell loss, whilst controls (not preconditioned, but exposed to 24 h hypoxia) demonstrated a 44% cell loss. Phosphoimmunoblot analysis of pro-survival signaling pathways revealed significant activation of serine threonine kinase Akt with DETA-NONOate (p < 0.01) and heat preconditioning (p < 0.05). DETA-NONOate also activated ERK 1/2 signaling (p < 0.05). In vivo implantation: 100,000 preconditioned (heat, hypoxia, or DETA-NONOate) myoblasts were implanted in SCID mouse tissue engineering chambers. 100,000 (not preconditioned) myoblasts were implanted in control chambers. At 3 weeks, morphometric assessment of surviving myoblasts indicated myoblast percent volume (p = 0.012) and myoblasts/mm(2) (p = 0.0005) overall significantly increased in preconditioned myoblast chambers compared to control, with DETA-NONOate-preconditioned myoblasts demonstrating the greatest increase in survival (p = 0.007 and p = 0.001 respectively). DETA-NONOate therefore has potential therapeutic benefits to significantly improve survival of transplanted cells.     

大鼠主动脉内皮损伤后核因子κB活性的动态变化及血管细胞黏附分子1的表达

目的 观察动脉损伤后核因子Κb活性的动态变化,以及血管局部血管细胞黏附分子1的表达,分析二者的关系.方法 SD大鼠以球囊剥脱主动脉内皮建立大鼠动脉损伤模型.按照术后处死的时间点,将动物分为8组:0 h(对照组)、12 h、24 h、1天、2天、3天、7天及14天,每组6只.凝胶迁移率实验检测各个时间点核因子Κb活性的动态变化,免疫组织化学观察血管细胞黏附分子1在血管局部的表达.结果 术后即刻以扫描电镜观察内皮完全剥脱.术后14天可见明显的增生内膜,模型建立成功.大鼠主动脉球囊损伤后,核因子Κb在术后12 h即有明显活化,高峰在1～3天,然后逐渐下降,14天左右接近术前水平.术后即刻无血管细胞黏附分子1表达,7天时在内膜表面及少量中膜平滑肌细胞可以看到血管细胞黏附分子1表达,术后14天时在未有内皮细胞覆盖处,新生内膜的近血管腔面少量表达,而主要的 阳性转移到新生内膜近内弹力板处.结论 核因子κB和血管细胞黏附分子1参与大鼠的主动脉损伤后的炎症过程;核因子κB的活化与失活成动态变化;血管细胞黏附分子1不同时间表达在不同的部位,核因子κB的活化与失活在血管细胞黏附分子1的表达与消退之前,核因子κB对血管细胞黏附分子1的表达起调节作用.     

Discontinuation of lamivudine treatment for hepatitis flare after kidney or heart transplantation in hepatitis B surface antigen-positive patients: A retrospective case series

BACKGROUND: Limited data are available on the clinical course of hepatitis B virus (HBV) infection after discontinuation of lamivudine prescribed for kidney or heart posttransplantation hepatitis flare OBJECTIVE: The purpose of this study was to investigate the reasons for discontinuation, subsequent reappearance of HBV DNA, and mortality in heart and kidney transplant recipients who discontinued lamivudine treatment. METHODS: This retrospective case series followed up male and female hepatitis B surface antigen (HBsAg)-positive Taiwanese transplant recipients from the National Taiwan University Hospital, Taipei, Taiwan, between July 1989 and January 1999. Biochemical, virologic, and serologic parameters and liver-related mortality of patients who discontinued lamivudine 100 mg QD prescribed for posttransplantation hepatitis flare were compared with those in a group of patients who continued use of lamivudine administered for the same indication over the same period of time. Serum HBV DNA levels were checked in all patients before and after discontinuation of lamivudine, and after resumption of lamivudine treatment and in patients with breakthrough hepatitis flare. RESULTS: A total of 39 HBsAg-positive transplant recipients (mean [SD] age, 45 [10.0] years) were identified during regular follow-up visits. Nine patients discontinued lamivudine use; 11 patients who continued it were selected as a control group. No significant between-group differences were observed in mean (SD) age (46 [14.0] vs 45 [6.9] years), sex (men/women,vs 1), type of transplant received (heart/kidney,vs ), or pretransplantation liver function test results. The reasons for discontinuation were informed patient decision (4 patients); YMDD mutation (2); self-discontinuation without physician consultation (2); and pregnancy (1). Of those who discontinued lamivudine, serum HBV DNA was undetectable at a mean of 30 (range, 9-47) months' follow-up in 6 (66.7%) of 9 patients. Lamivudine treatment was resumed in 3 patients on reappearance of HBV DNA, and a subsequent rapid decline in the serum HBV DNA was observed. The liver-related mortality rate was not significantly higher in patients who discontinued treatment compared with continuously treated patients (both, 0%). The between-group difference in overall mortality rates was not significant (22.2% and 18.2%, respectively). CONCLUSIONS: This case series illustrated a variety of clinical situations in which discontinuation of lamivudine treatment prescribed for posttransplantation hepatitis flare may occur. However, liver-related mortality was not increased in these patients compared with those who continued lamivudine treatment.     

Detection of Epstein-Barr virus infection and gene expression in human tumors by microarray analysis

Epstein-Barr virus (EBV) genome-chips are employed to determine the EBV infection rate and to reveal the gene expression patterns of EBV in tumor biopsies. These chips are produced with 71 consecutive PCR-amplified EBV DNA fragments of 1-3 kbp covering the entire EBV genome. The specificity of the EBV-chips is determined by hybridizing the DNA on the chips with biotin-labeled cDNA probes reverse transcribed from the mRNA of P3HR1 cells, which were B-cell infected latently by EBV. Hybridization results revealed only the expression of EBNA1, EBNA2, EBER1 and EBER2 in these cells. On the other hand, EBV lytic genes are expressed after the cells are treated with 12-O-tetradecanoylphorbol-13-acetate and sodium butyrate to induce the EBV lytic cycle. Fourty-four tumor biopsies from different organs are assayed with these chips, which showed many defined and interesting EBV gene expression patterns. This study demonstrates that the EBV-chip is useful for screening infection with EBV in tumors, which may lead to insights into tumorigenesis associated with this virus.