蛙皮素对PC-3细胞骨架及细胞内游离Ca~(2+)的影响

目的:观察蛙皮素(BBS)对前列腺癌PC-3细胞骨架形态及细胞内游离Ca2+([Ca2+]i)浓度的影响。方法:①利用免疫荧光法(IH),结合激光扫描共聚焦显微镜(LSCM)检测10-5mol/L浓度BBS处理的PC-3细胞角蛋白(CK)的表达,以反映其对细胞骨架形态的影响;②应用Fluo-3/AM荧光标记技术和LSCM检测不同浓度BBS(10-9、10-7、10-5mol/L)处理的PC-3细胞[Ca2+]i浓度。结果:①10-5mol/L浓度的BBS可促进PC-3细胞CK表达及伪足形成;②BBS可提高PC-3细胞[Ca2+]i浓度,并具有浓度依赖性。结论:实验证明一定浓度的BBS可明显提高PC-3细胞[Ca2+]i浓度及CK表达,进而影响PC-3细胞骨架形态。本研究为探索BBS应用于肿瘤研究以及BBS作用后细胞内信息传递途径提供了基础。     

复合干细胞生物陶瓷在裸鼠异位成骨中的评价

目的 研究h-BMP-2基因转染骨髓间充质干细胞(BMSCs)在复合煅烧骨、β-TCP或直接植入裸鼠股部后的成骨能力。方法 通过影像学、组织学和形态计量学等方法,观察未经诱导、OS液诱导和h-BMP-2基因转染BMSCs在复合煅烧骨,或多孔β-TCP后植入裸鼠皮下,或直接制成细胞悬液注入,在4、8、12周诱导成骨和材料降解情况。结果 在裸鼠皮下,单纯生物陶瓷不能诱导成骨,而复合了未诱导、OS液诱导和h-BMP-2基因转染BMSCs的生物陶瓷均能成骨,成骨量为h-BMP-2基因转染组>OS液诱导组>未经诱导组(P<0.05),B-TCP可随骨长入而降解;注入裸鼠肌肉的OS液诱导的和h-BMP-2转染的BMSCs均能诱导成骨,而未经诱导MSCs则不能成骨。结论 复合人BMP基因转染BMSCs的β-TCP是一种理想的骨修复材料。     

大鼠大脑中动脉闭塞后丘脑钙调磷酸酶含量与活性的研究

目的 揭示大脑中动脉闭塞(MCAO)后丘脑钙调磷酸酶(CaN)的时空变化规律，探讨CaN的作用机制。方法 制备大鼠大脑中动脉永久性闭塞模型，分别测定缺血后不同时间点病灶侧丘脑CaN的活性和含量。结果 缺血后24h始丘脑CaN的含量下降且不恢复；CaN的活性在缺血后2h和4h减弱，6h始恢复至正常水平。可见，CaN的活性与含量分离。结论 大脑中动脉闭塞后丘脑CaN活性独特的时间变化规律显示其参与介导继发性丘脑损伤，可能具有毒性作用。     

低血容量性休克大鼠心肌细胞Ca2+浓度及膜电位的变化

目的 旨在探讨低血容量性休克大鼠心肌细胞Ca2 浓度及其膜电位的变化.方法 选用Wistar大鼠84只,随机分成休克高渗复苏组(HES组)、生理盐水复苏组(NS组).建立休克模型,按7个时相(休克前、休克、复苏后5、15、30、60、90min)处死大鼠.取心室肌细胞培养传代,用Fluo-4/AM为游离钙荧光探针、JC-1荧光染色,流式细胞仪分别检测不同时相心肌细胞Ca2 浓度及线粒体膜电位.结果 HES组在休克、复苏后5、15、30min各时间点心肌细胞Ca2 浓度较休克前明显升高,其膜电位较休克前显著降低(P＜0.01);在复苏后60、90min心肌细胞Ca2 浓度及线粒体膜电位与休克时比较差异有显著性意义(P＜0.01);NS组在休克、复苏后各个时相与休克前比较心肌细胞Ca2 浓度均明显升高,其膜电位明显下降(P＜0.01);复苏后各时间点与休克时比较差异无显著性意义(P＞0.05);HSE组和NS组在休克后60、90min心肌细胞Ca2 浓度及其膜电位差异有显著性意义(P＜0.01).结论 低血容量性休克可诱发大鼠心肌细胞Ca2 浓度升高,线粒体膜电位下降,导致心肌细胞电生理活动障碍;高渗盐溶液不但可改善低血容量休克时心肌细胞Ca2 浓度,而且能有效地稳定其线粒体膜电位;而生理盐水对心肌细胞Ca2 浓度及其膜电位的作用不显著.     

草酸钙结石形成对肾组织bikunin和IαI表达的影响

目的研究肾草酸钙结石形成对肾组织bikunin基因和间α胰蛋白酶抑制物(IαI)蛋白表达的影响,探讨bikunin在尿结石形成中的意义。方法诱导实验性大鼠肾草酸钙结石模型,收集结石大鼠、正常大鼠、临床肾结石和非结石患者每组各8例的肾组织标本。采用免疫组化、逆转录聚合酶链反应(RT-PCR)和计算机图像分析技术分别检测所有大鼠和人肾组织中bikuninmRNA和IαI蛋白的表达水平。结果正常大鼠和非结石患者肾组织均存在bikuninmRNA和IαI蛋白的表达。肾草酸钙结石形成后,结石大鼠肾组织IαI蛋白的灰度值和bikuninmRNA的相对表达水平分别为198.43±15.17、0.70±0.14;肾结石患者肾组织IαI蛋白的灰度值和bikuninmRNA的相对表达水平分别为263.25±17.41、1.27±0.13,分别和对照组相比,均显著增加(P<0.05)。结论Bikunin作为构成IαI的轻链结构,在肾草酸钙结石形成后,bikuninmRNA的表达迅速增强,提示机体通过肾脏合成更多的bikunin来抑制肾草酸钙结石的形成。     

老年人血清胆红素水平与冠状动脉病变程度的关系

目的观察老年人血清胆红素与冠状动脉病变的关系。方法经冠状动脉造影确诊的冠心病患者80例,其中冠状动脉轻度狭窄组15例,中度狭窄组32例,重度狭窄组33例;另外选取冠状动脉造影正常者40例做对照。采用重氮苯磺酸法测定血清胆红素水平,并对胆红素与各因素进行直线相关分析。结果冠心病组血清胆红素水平明显低于正常对照组,血清胆红素水平与冠状动脉病变程度成显著负相关关系(r=-0.26,P<0.05)。结论冠心病患者血清胆红素水平较正常人明显降低。低血清胆红素可能是冠心病的一种危险因素。血清胆红素水平与冠状动脉狭窄程度有明显相关性。     

Thyrotrophin-Releasing Hormone Raises Cytosolic Free Calcium Concentration in Human Adenomatous Somatotrophs and Corticotrophs; Comparison with in vivo Responsiveness to Thyrotrophin-Releasing Hormone in Patients with Acromegaly or Cushing's Disease

The effect of thyrotrophin-releasing hormone (TRH) on intracellular free Ca²⁺ concentration, [Ca²⁺)i, was investigated with the fluorescent dye fura-2 in cell suspensions obtained from 13 human growth hormone-secreting adenomas and 6 adrenocorticotrophin-secreting adenomas. Preoperatively, 9 out of 13 acromegalic patients showed a positive growth hormone response to TRH administration while none of the 6 patients with Cushing's disease had a plasma adrenocorticotrophin increase after TRH injection. In all the growth hormone-secreting adenomas the addition of TRH (100 nM) caused a significant rise in [Ca²⁺]i (from a resting level of 133±40 (±SD) to a value of 284±119 nM at 100 nM TRH, n = 42; P<0.001). The transient induced by TRH was found to have a dual origin, one due to Ca²⁺ mobilization from intracellular stores which was maintained in presence of EGTA (3mM) and verapamil (10 μM) and a plateau phase due to Ca²⁺ influx from the extracellular media. Somatostatin (0.1 μM) lowered both resting [Ca²⁺]i and TRH-induced transients. The effect of gonadotrophin-releasing hormone on [Ca²⁺]i was evaluated on cell suspensions obtained from 6 growth hormone-secreting adenomas. Gonadotrophin-releasing hormone (100 nM) caused a marked rise in [Ca²⁺]i (from 179±25 to 283±15nM) on the cell suspension obtained from the only in vivo responsive adenoma while it was ineffective in the remaining 5. Although TRH was ineffective in modifying plasma adrenocorticotrophin levels in all patients with Cushing's disease, in 5 out of 6 tumors the addition of 100 nM TRH caused a significant rise in [Ca²⁺]i (from 102.5 ± 36 to 163±66 nM, n = 22; P < 0.005). However, the effect of TRH on [Ca²⁺]i was significantly lower than that caused by arginine vasopressin, a physiological stimulator of adrenocorticotrophin release ([Ca²⁺]i values; 145±78 nM at 100 nM TRH versus 300±140 at 10 nM arginine vasopressin, n = 15; P<0.05). Moreover, the effect of arginine vasopressin on [Ca²⁺]i was detectable at concentrations as low as 0.1 nM while TRH was effective at concentrations higher than 1 nM. By contrast, gonadotrophin-releasing hormone was ineffective in increasing [Ca²]i in all the adrenocorticotrophin-secreting adenomas studied. Collectively, these data indicate that sensitivity to TRH is present in almost all the growth hormone- and adrenocorticotrophin-secreting adenomas independently of the responsiveness of the individual patients to the peptide.     

Fibronectin inhibits endocytosis of calcium oxalate crystals by renal tubular cells

BACKGROUND: Fibronectin (FN; 230 kDa) is a multifunctional alpha2-glycoprotein distributed throughout the extracellular matrix and body fluids. We recently reported that FN has a protective effect against injury of renal tubular cells by exposure to oxalate and calcium oxalate (CaOX) crystals and inhibits the adhesion of CaOX crystals to renal tubular cells. In the study presented here, we investigated whether FN has inhibitory effect on crystal endocytosis by renal tubular cells. METHODS: The inhibitory effect of FN on endocytosis of CaOX crystals by MDCK cells was examined by using a radioactivity uptake assay. Also, crystal endocytosis by cells was morphologically assessed by means of transmission electron microscopy (TEM). RESULTS: FN had inhibitory effects on CaOX crystal endocytosis by MDCK cells. The morphological TEM study showed that few crystals were taken into cells when FN was added compared to the number of crystals when FN was not added. CONCLUSION: We found that FN had the inhibitory effects on the interaction between crystals and renal tubular cells, including the adhesion or endocytosis of crystals by cells.     

原发性高血压病患者颈动脉粥样硬化程度与血清胆红素水平的相关性研究

目的 探讨高血压病患者颈动脉粥样硬化程度与血清胆红素水平的关系.方法 158 例高血压病患者行双侧颈动脉超声多普勒检查,根据检测结果分为颈动脉粥样硬化组和正常颈动脉组.记录各组年龄、性别、体重指数、吸烟史、糖尿病史和血压,测定血清总胆红素及其他生物化学指标.结果 颈动脉粥样硬化组的血清总胆红素水平(8.37±3.53)μmol/L显著低于正常颈动脉组(14.53±4.61)μmol/L(P＜0.05).多因素回归分析显示低胆红素血症与颈动脉粥样硬化呈显著正相关(χ2wald=4.41,P=0.029,OR=3.72).结论 低胆红素血症是高血压病患者发生颈动脉粥样硬化的独立危险因素.