Apoptosis of Human Trabecular Meshwork Cells Induced by Transforming Growth Factor-p2 in vitro

Summary: Whether transforming growth factor-β2 (TGF-β2) induces apoptosis of human trabecular meshwork cells was investigated in vitro. Cultured 3-5 passage human trabecular meshwork cells were treated with 0 (control), 0.32, 1, 3.2 ng/ml TGF-β2 for 48 h and divided into control group and experimental group. The apoptosis of human trabecular meshwork cells was examined by transmisson electron microscopy, TUNEL technique and flow cytometry. The results showed characteristic morphologic changes of apoptotic cells were observed under transmission electron microscopy.DNA fragmentation of human trabecular meshwork cells was found by TUNEL technique. Quantitative analysis of flow cytometry showed that percentages of apoptotic human trabecular meshwork cells were (2.79±0.44) %, (4.43±1.17) % and (9. 60±2.05) % respectively with different concentrations [1 ng/ml (P＜0. 05), 3.2 ng/ml (P＜0.01)] of TGF-β2 with the difference being significant between experimental group and control group[(1. 41±0.34) %]. It was concluded that TGF-β2 can induce apoptosis of human trabecular meshwork cells in vitro and may be involved in the decrease of trabecular meshwork cells in the patients with primary open angle glaucoma and aging of normal people.     

降钙素基因相关肽对人主动脉平滑肌增殖的影响

以人主动脉平滑肌细胞（ＳＭＣ）为模型，用３Ｈ－ＴｄＲ掺入量测定法观察了降钙素基因相关肽（ＣＧＲＰ）对细胞增殖的影响，并对细胞内Ｃａ２＋浓度进行了测定。结果表明：ＣＧＲＰ对人主动脉ＳＭＣ有明显抑制作用，呈浓度依赖性，最佳浓度为１０ｎｍｏｌ／Ｌ，抑制率达４７．４４％。胞浆内游离Ｃａ２＋浓度明显降低，提示ＣＧＲＰ降低细胞内Ｃａ２＋浓度可能是其抑制ＳＭＣ增殖的作用机制之一。     

l-Aspartic acid potentiates ‘slow’ inward current in cultured spinal cord neurons

Intracellular recordings (current-and two electrode voltage-clamp) were made from mouse spinal cord neurons grown dissociated in tissue culture. Neurons were bathed in elevated concentrations of calcium (Ca) and sometimes tetraethylammonium (TEA). Brief depolarizing current injections activated graded ‘after-depolarizations’ which summated to trigger prolonged all-or-none action potentials. Under voltage-clamp both of these active potentials were manifest as ‘slow’ inward current. Net inward current was observed in some neurons during 0.5–1.0 s depolarizing command steps. However, in the majority of cases the inward current was seen as large inward current tails (outward current relaxations) upon repolarization of the membrane potential to holding values. Cadmium (Cd) blocked this slow inward current, ‘after-depolarizations’ and prolonged action potentials. Applications of l-aspartic acid increased the magnitude of net inward current evoked by command steps and potentiated and prolonged inward current tails. This potentiation and prolongation of voltage-dependent inward current likely accounts for the prolonged action potentials or ‘bursting’ characteristic of responses to l-aspartic acid and related amino acids such as N-methyl-d-aspartic acid.     

Bilateral alpha-melanocyte stimulating hormonergic fiber system from zona incerta to cerebral cortex: combined retrograde axonal transport and immunohistochemical study

We employed a highly sensitive combination method of retrograde tracing and immunohistochemistry to identify an alpha-melanocyte-stimulating hormone (alpha-MSH)-containing fiber pathway from zona incerta to cerebral cortex. Biotin-horseradish peroxidase injected into the parietal cortex of the rat labeled a number of neurons in the zona incerta bilaterally, and simultaneous staining with an alpha-MSH antiserum revealed that a part of these neurons are alpha-MSHergic.     

BSO增强MRP过表达肺癌细胞对顺铂敏感性的作用机制研究

目的：评价使用丁胱亚磺酰亚胺(BSO)克服肿瘤细胞由于高表达MRP而引起对顺铂耐药的可行性，并初步探讨其增敏的作用机制。方法：用基因转染的方法成功建立了一株mrp基因高表达的肺癌细胞株(SPC-A-1／MRP)的基础上，检测BSO作用前后转染细胞对顺铂敏感性的差异，从酶活性测定和转录水平观察了上述过程中谷胱甘肽解毒系统的变化。结果：实验表明同对照(转染不含目的基因的空载质粒)的SPC-A-1／MRP(一)细胞相比，SPC-A-1／MRP细胞对顺铂出现了明显的耐受，BSO可以有效增强MRP高表达的细胞对顺铂的敏感性。BSO通过显著抑制由顺铂引起的肿瘤细胞内GSH解毒系统的活化和MRP蛋白含量升高，有效的克服了肿瘤细胞接触顺铂后过表达MRP而引起的化疗耐受。结论：高表达MRP可以引起肿瘤细胞对顺铂的耐受，BSO针对MRP介导的顺铂耐药有很好的增敏效果。     

不同浓度臭氧对脊髓神经元的影响

目的 观察臭氧(O3)对体外培养脊髓神经元(SCN)的影响,为临床合理应用O3提供实验依据.方法 体外培养SCN随机分为4组,行NSE、Bcl-2、Bax染色计数阳性细胞率,并在倒置相差显微镜下观察细胞形态学变化.结果 随O3浓度增加,神经元胞体皱缩或肿胀,突起变短断裂成串珠状,部分细胞破裂消失.Ⅲ组、Ⅳ组NSE免疫组化染色、免疫荧光阳性细胞率低于Ⅰ组,Ⅱ组、Ⅲ组、Ⅳ组Bcl-2阳性细胞率低于Ⅰ组,Ⅱ组、Ⅲ组Bax阳性细胞率高于Ⅰ组.结论 低浓度O3引起SCN凋亡,高浓度引起SCN坏死.     

阿魏酸钠对一氧化碳供体硝普钠诱导的海马神经元凋亡的保护作用

目的 探讨阿魏酸钠(sodium ferulate,SF)对NO供体硝普钠(SNP)引起的大鼠海马神经元凋亡的影响.方法 采用MTT比色分析测细胞存活率,Hoechst 33258荧光染色及DNA琼脂糖凝胶电泳分析等方法 检测凋亡.结果 不同剂量SF(10～160 μmol/mL)预处理海马神经元6h可剂量依赖地对抗SNP引起的神经元凋亡,提高神经元的存活率;减少SNP引起的核固缩、凝聚和碎裂现象;DNA凝胶电泳图谱未见典型的"梯子状"改变.结论 SF对NO供体SNP诱导的海马神经元凋亡具有明显的保护作用.     

顺铂诱导人骨肉瘤细胞凋亡及其分子机制的初步研究

目的　研究顺铂 (c DDP)对人骨肉瘤细胞的生物学效应及其作用机制。方法　骨肉瘤细胞经 c DDP处理后 ,用台盼蓝技术法检测 c DDP的 IC50 ,采用流式细胞仪、DAPI荧光染色、TUNEL 及 DNA电泳检测细胞凋亡。结果　c DDP在一定浓度范围内以浓度依赖的方式抑制骨肉瘤细胞生长 ,其 IC50 为 1.0 5 μg/ ml± 0 .2 5 μg/ ml。 0 .5～ 2 .0 μg/ mlc DDP处理骨肉瘤细胞后 ,流式细胞仪检测出凋亡峰 ,流式细胞光度计下可见明显的凋亡细胞形态特征 ,琼脂糖凝胶电泳出现 DNA梯形条带。结论　c DDP在体外可诱导骨肉瘤细胞凋亡 ,这种诱导细胞凋亡的能力是 c DDP疗效的基础 ,在对骨肉瘤的治疗中有着巨大的潜力。     

Application of a GM1 ganglioside beta-galactosidase microassay method to diagnosis of GM1 gangliosidosis

The enzymatic diagnosis of GM1 gangliosidosis, including the diagnosis of heterozygosity, requires a microassay of GM1 ganglioside beta-galactosidase activity in lymphocytes and cultured skin fibroblasts. We have adopted high-performance liquid chromatography (HPLC) to the assay of this enzyme and can measure the activity in crude samples fluorometrically. Reaction conditions were examined to determine those optimal for the assay of GM1 ganglioside beta-galactosidase activity in lymphocyte and skin fibroblast homogenates. Under these optimal conditions, reduced enzymatic activities could be detected in lymphocytes and cultured skin fibroblasts from three patients with GM1 gangliosidosis. Thus, this assay can be used for the diagnosis, rather than the usual assays employing radioactive or artificial substrates.     

Use of cultured human cells for biochemical analysis

The use of cultured human cells for biochemical analysis is increasing. This reflects the many advantages of such cells over tissue samples: independence of the measurements from the biological milieu of the donor, better control of experimental variables and the possibility of immortalizing the patient via his cells. Concomitant with these advantages, however, are certain new experimental variables which, if not properly controlled, can yield spurious results. This paper describes the types of cultured human cells that are generally available and the basic steps involved in their culture, as well as a discussion of the sources of variability in biochemical measurements which can be attributed to cell culture.