小颗粒致密低密度脂蛋白氧化特性及对血管内皮细胞脂质过氧化的影响

了解小颗粒致密低密度脂蛋白中抗氧化维生素含量、氧化特性 ,探讨其对血管内皮细胞脂质过氧化的影响。采用二次密度梯度超速离心的方法分离制备小颗粒致密低密度脂蛋白 ,高压液相色谱测定其抗氧化物质维生素A、E和 β 胡萝卜素 ;连续监测小颗粒致密低密度脂蛋白在 2 34nm的吸光度以测定其氧化敏感曲线 ;在血管内皮培养液中分别加入不同浓度的小颗粒致密低密度脂蛋白 ,培养后测定培养液丙二醛的浓度。实验成功分离小颗粒致密低密度脂蛋白 ,与大而轻低密度脂蛋白相比 ,维生素A、E和 β 胡萝卜素等抗氧化物质及总抗氧化能力明显减少 ,只有大而轻低密度脂蛋白的 6 5 %、39%和 2 4 % ,故小颗粒致密低密度脂蛋白氧化的延迟时间只有大而轻低密度脂蛋白的 37.5 % ,但硫代巴比妥酸反应物质值及氧化速率分别是大而轻低密度脂蛋白的 1 .7倍和 1 .2 8倍 ;培养液中丙二醛含量随加入脂蛋白的浓度和作用时间而增高 ,2 4h时小颗粒致密低密度脂蛋白 5 0mg组、1 0 0mg组、1 5 0mg组与相同剂量大而轻低密度脂蛋白组比较丙二醛显著增高 (P <0 .0 5 )。上述结果提示 :小颗粒致密低密度脂蛋白中抗氧化物质及抗氧化能力下降 ,氧化敏感性增高 ,并促进内皮细胞过氧化损伤     

胰腺导管癌中血管生成、细胞增殖指数、DNA倍性检测的临床意义

目的:探讨血管生成、细胞增殖指数、DNA倍性在胰腺导管癌发生、发展中的作用及临床意义。方法:对29例胰腺导管癌和7例慢性胰腺炎患者的石蜡包埋标本作苏木精鄄伊红(HE)染色,CD34、Ki67免疫组织化学染色,镜下计算微血管密度(MVD)及Ki67阳性细胞比例,同时用流式细胞仪(FCM)检测细胞核DNA倍性,计算异倍体出现率及S期比例,并结合临床病理资料对各项指标作相关分析。结果:胰腺导管癌和慢性胰腺炎都有较多的新生血管。MVD值在胰腺导管癌高、中、低分化3组之间差异无显著性。按肿瘤直径分为≤1.5cm、1.6～2.9cm、≥3cm3组,此3组间MVD值、Ki67阳性细胞百分率、DNA异倍体出现率及肿瘤周围有无浸润的差异都非常显著(P<0.01)。肿瘤越大,MVD值、Ki67阳性细胞百分率及DNA异倍体出现率越高。结论:胰腺导管癌的发生、发展伴血管生成和DNA合成增加,联合测定MVD、Ki67阳性细胞百分率、DNA倍型可能为胰腺导管癌临床预后预测提供辅助参考指标。     

Differential effects of cannabis extracts and pure plant cannabinoids on hippocampal neurones and glia

We have shown previously that the plant cannabinoid cannabidiol (CBD) elevates intracellular calcium levels in both cultured hippocampal neurones and glia. Here, we investigated whether the main psychotropic constituent of cannabis, Δ⁹-tetrahydrocannabinol (THC) alone or in combination with other cannabis constituents can cause similar responses, and whether THC affects the responses induced by CBD. Our experiments were performed with 1 μM pure THC (pTHC), with 1 μM pure CBD (pCBD), with a high-THC, low CBD cannabis extract (eTHC), with a high-CBD, low THC cannabis extract (eCBD), with a mixture of eTHC and eCBD (THC:CBD = 1:1) or with corresponding ‘mock extracts’ that contained only pTHC and pCBD mixed in the same proportion as in eTHC, eCBD or the 1:1 mixture of eTHC and eCBD.     

Stat3显性负性基因调控人结肠癌细胞增殖与凋亡的分子机制

目的 探讨转染Stat3（转录信号传导子和激活子3）显性负性基因Stat3β质粒阻断人结肠癌细胞系SW480细胞的Stat3信号传导通路对人结肠癌细胞增殖和凋亡的影响及可能的机制.方法 应用阳离子脂质体向人结肠癌细胞系SW480细胞中转染携带Stat3β基因的质粒,四唑盐法检测细胞增殖能力,流式细胞术检测细胞周期和细胞凋亡,反转录聚合酶链反应检测Stat3靶基因cyclinD1、bcl-xL mRNA表达情况.数据统计分析采用独立样本t检验.结果 转染Stat3β质粒36 h后,SW480细胞的增殖受到显著抑制（t=5.216,P=0.006）;G0/G1期的细胞比例由40.37%上升至67.25%,S期细胞由44.68%下降至31.23%;发生早期凋亡的细胞比例由5.34%上升至24.42%;同时cyclin D1、bcl-xLmRNA表达水平较对照组显著下降（t=5.228,P=0.010;t=3.517,P=0.025）.结论 转染携带Stat3β基因的质粒可以通过下调Stat3靶基因的表达抑制人结肠癌细胞的增殖,促进凋亡,为以Stat3为靶点的结肠癌基因治疗提供了实验基础.     

热缺血再灌注损伤影响肝脏细胞周期检查点调控的基因表达分析

目的动态观察肝脏热缺血再灌注损伤（WIRI）对细胞周期检查点基因的表达影响，研究其分子机制帮助了解那些与热缺血再灌注相关的疾病。方法采用成组对照的实验设计，利用微阵列芯片和逆转录-聚合酶链反应（PCR）联合分析技术，分析SD大鼠热缺血再灌注损伤处理后的基因表达变化（其中芯片分析8只、RT-PCR定量分析16只）；运用系统生物学分析方法对功能基因进行聚类。结果分别得到了热缺血再灌注损伤处理后肝脏的细胞周期各检查点基因及早期即刻基因表达数据，将其中与细胞周期密切相关的的功能基因（上调的223条、下调的62条变化幅度均大于3倍）做进一步分析。结论肝脏热缺血再灌注损伤通过细胞周期／检查点控制基因影响细胞周期G1／S、G2／M的运行，抑制DNA的合成和染色体的分裂。推测可能影响受损的DNA双链自我修复和后期的组织细胞再生、凋亡。     

塞来昔布对大鼠心脏移植急性排斥反应的抑制作用

目的观察塞来昔布对大鼠心脏移植急性排斥反应的抑制作用。方法以SD大鼠为供者,Wistar大鼠为受者,进行40次腹部异位心脏移植。采用HE染色和原位末端标记(TUN EL)技术检测移植心切片,进行排斥反应的病理分级并计算移植心肌细胞的凋亡指数(AI)。结果移植心的细胞凋亡主要发生于心肌细胞;移植后第3、5d,塞来昔布治疗组心肌细胞凋亡指数分别为:1.03±0.42和3.28±2.42;对照组分别为2.35±1.51和11.35±3.46;两组比较,差异有统计学意义(P<0.001)。结论细胞凋亡是心脏移植急性排斥中组织损伤的重要机制;塞来昔布能明显抑制心肌细胞凋亡。     

氧化砷对小鼠腹水型肝癌细胞的作用

目的 :研究氧化砷对移植性腹水型肝癌细胞的抗癌作用。方法 :肝癌细胞 (1 8× 10 7)接种入小鼠腹腔。对照组注射NS(0 8mL) ,余组用氧化砷 (1,2 ,3μmol/L)腹腔注射 ,每日 1次 ,共 10日。结果 :第 10天腹水细胞计数 ,1,2和 3μmol/L组瘤细胞锐减 (P <0 0 5 ) ,但第 16天腹水肿瘤细胞急骤增加。结论 :氧化砷对腹水肿瘤细胞有暂时抑制作用。     

间期细胞原位PCR检测B细胞系恶性淋巴瘤

目的：应用原位PCR技术检测B细胞系恶性淋巴瘤。方法：采用免疫球蛋白重链（IgH)基因第三互补决定区（CDR－Ⅲ）的引物，dig-11-dUTP标记物，应用直接原位PCR技术检测Ⅲ-Ⅳ级恶性淋巴瘤的间期淋巴细胞，结果：在初诊的15例恶性淋巴瘤患中，12例检测到IgH基因重排；4例临床表现呈现淋巴瘤性白血病患，治疗后骨髓完全缓解，2例间期细胞原位PCR仍显示有IgH基因重排，6个月复发，结论：间期细胞原位PCR技术能敏感、准确地检测Ⅲ级以上的恶性淋巴瘤，并帮助预测复发，为一有效的基因诊断方法。     

Erythropoietin production in healthy volunteers subjected to controlled hypobaric hypoxia: further evidence against a role for adenosine

Aims Objective of this study was to investigate whether adenosine modulates renal erythropoietin production.
Methods In the present study erythropoietin production was stimulated by hypobaric hypoxia by subjecting healthy volunteers to a simulated altitude of 4000  m in a low pressure chamber for 5.5  h. During exposure to hypoxia the subjects received i.v. in a randomized, single-blind, cross-over fashion the non-specific adenosine antagonist theophylline, the adenosine reuptake inhibitor dipyridamole and placebo.
Results Contrary to the working hypothesis, theophylline did not decrease and dipyridamole did not further boost erythropoietin concentrations.
Conclusions The results are in agreement with our earlier study using haemorrhage as a controlled physiological stimulus of erythropoietin production, and would question a major role for adenosine as a mediator of renal erythropoietin production.     

Monolayer cultures of normal human bone cells contain multiple subpopulations of alkaline phosphatase positive cells

Summary Cytochemical staining of normal human bone cells in monolayer cultures for alkaline phosphatase (ALP) indicated that the cultures contained mixed-cell populations. Time course evaluations of the cytochemical staining revealed, in addition to the ALP-negative cell population, at least two subpopulations of ALP-positive human bone cells with different levels of ALP. A cytochemical method has been developed which separates the ALP-positive cells into high and intermediate ALP subpopulations. In this method, human bone cells were stained for ALP using an azo-dye method and incubating at 4°C for 10 and 30 minutes, respectively. We defined the cell population that stained positively for ALP at 10 minutes as strong ALP-positive cells, and both strong and intermediate cells were stained at 30 minutes. The intermediate cells were determined from the difference between the values at the two time points. The intra- and interassay variations of the assay, with the same investigator in blinded investigations, were both less than 10% and the interobserver variation was approximately 25%. Analysis of the distribution of ALP levels in cells with a laser densitometer confirmed the presence of at least three cell subpopulations. 1,25(OH)₂D₃ treatment increased the proportions of both ALP-positive cell populations, whereas TGF-beta treatment increased only the intermediate ALP-positive cell population. On the contrary, fluoride increased the proportion of the strong ALP cells, and IGF-1 had no effect on the proportions of either ALP-positive subpopulation. When the ALP-specific activity was compared with the percentage of each ALP-positive subpopulations for the cells treated with effectors, the ALP-specific activity correlated with the total ALP-positive and with the strong ALP-positive populations but not with the intermediate ALP-positive subpopulation. In summary, this study represents the first evidence that normal human bone cells in monolayer cultures contained at least two subpopulations of ALP-positive cells, and that bone cell effectors could have differential effects on each cell population.