3H-fucose incorporation into glycoproteins of toad bladder epithelial cells

Electron microscope autoradiography was used to detect the incorporation of ³H-fucose into glycoproteins of toad bladder epithelial cells. After short exposure to ³H-fucose, without a chase period, the Golgi regions of all four cell types were labeled. When exposure to ³H-fucose was followed by chase periods (1, 3, 4 and 6 hours) the apical and basal-lateral plasma membranes of granular cells were heavily labeled. Apical granules and the cytoplasm of granular cells were also labeled, suggesting that they both provide the means for glycoprotein transfer from the Golgi to the plasma membranes. The heaviest labeling in mitochondria-rich cells, after the 1- and 3-hour chase periods, was over the apical tubules, although the apical and basal-lateral plasma membranes were also heavily labeled. After the 4- and 6-hour chases, the labeling of the apical tubules decreased, whereas the labeling of the plasma membranes increased, strongly suggesting that in these cells apical tubules play a major role in the transfer of glycoproteins from Golgi to the plasma membrane. Our results demonstrate that the route of ³H-fucose incorporation into plasma membrane glycoproteins and the rate of glycoprotein synthesis and breakdown are not the same in the two major epithelial cell types in toad bladder.     

Glucocorticoid receptor and heat shock protein 90 in peripheral blood mononuclear cells from asthmatics

目的探讨糖皮质激素受体(GR)和热休克蛋白90(HSP90)mRNA在糖皮质激素敏感型(SS)、依赖型(SD) 和抵抗型(SR)哮喘中的表达及其在SR哮喘发病中的作用。 方法采用反转录-聚合酶链(RT-PCR)的方法分别测定正常人(10例)、SS哮喘(10例)、SD哮喘(5例)和 SR哮喘(6例)的外周血单个核细胞(PBMC)中GR mRNA和HSP90 mRNA的表达,并在体外用IL-2、IL-4分 别、联合刺激上述细胞观察其受刺激后GR mRNA和HSP90 mRNA表达的改变情况。 结果 SR哮喘的GR和HSP90 mRNA表达水平最高(分别为0.730±0.171和1.122±0.165),SS哮喘次之 (分别为0.359±0.350和0.885±0.250),SD哮喘最低(分别为0.017±0.008和0.078±0.039)。正常人有 一定表达(分别为0.052±0.013和0.362±0.101)。GR和HSP90 mRNA的表达各组间相比P＜0.05。正 常人、SS、SD和SR哮喘HSP90/GR的比值分别为7.15±1.84、8.39±7.95、5.51±3.30、1.57±0.18,SR哮喘 HSP90/GR比值明显低于前三组(P＜0.05)。IL-2和IL-4单独刺激对SS、SD和SR哮喘的GR、HSP90 mRNA表达无明显影响,二者联合刺激可使SS、SD和SR哮喘GR mRNA表达以及SS、SD哮喘HSP90 mRNA 表达增强,但不能使SR哮喘HSP90 mRNA表达增强。 结论 SR哮喘中HSP90 mRNA表达相对不足造成HSP90/GR比值降低可能是SR哮喘形成的原因之一, IL-2+IL-4对GR和HSP90 mRNA表达的不同调节作用可能是形成SR哮喘HSP90/GR比值降低的原因之一。     

Children of alcoholics: Attention, information processing and event-related brain potentials

Recent studies on biological markers and risk factors for alcoholism have distinguished between nonalcoholic individuals with a family history of alcoholism and those without such a family history on measures of event-related brain potentials. The main finding of these "high-risk" studies is a smaller amplitude of the P300 component in males with a history of paternal alcoholism. This relationship between P300 amplitude and a family history of paternal alcoholism has been observed in adults and children. Consequently, several authors have suggested that a reduced P300 amplitude could serve as a vulnerability marker for alcoholism. We address several conceptual and methodological issues involved in the study of event-related potentials in children at high risk for alcoholism. Subsequently, the ongoing high-risk study of the Amsterdam Institute for Addiction Research is described briefly.     

Psychological mechanisms of enhanced risk of addiction in children of alcoholics: a dual pathway?

The background and rationale of a recently started project of the Amsterdam Institute for Addiction Research are outlined. This project is aimed at the psychological mechanisms underlying an enhanced risk of (later) addiction in children of alcoholics and the relationship with childhood psychopathology. A dual pathway mechanism is proposed, in which the type of alcoholism of the parent plays a major role. The child of a multigenerational primary alcoholic parent may suffer from an inherited mild dysfunction of the prefrontal cortex, expressed in neuropsychological and personality characteristics similar to those of the alcoholic parent. These are impulsive, aggressive and reward-seeking behaviour, response perseveration and, in some children, related psychopathology such as conduct disorders. For a child of a secondary alcoholic parent, another mechanism is proposed. In these children, stress and social learning may lead to negative affectivity and repressive coping style, with emotional problems at a later age, and the risk of falling into the "circle of secondary alcoholism". In both pathways, alcohol-related expectancies are suggested to constitute a "final common pathway" between different risk factors and later alcohol abuse. Specific expectancies might be related to different pathways and to gender differences in later drinking patterns.     

小檗碱电化学检测器在中(成)药流动注射分析中的应用

中药材及其制剂,因成分复杂,对其有效成分的测定,目前大多尚未建立适宜的方法。文献报道的测定方法有薄层—分光光度法、薄层扫描法、萃取—分光光度法、柱色谱—分光光度法及高效液相色谱法等,这些方法大多操作繁琐、分析周期较长、且分析的精密度和准确度亦不够理想。近年来,随着流动注射分析(FIA)及化学传感器的发展,中成药中有效成分的分析有了新的发展。本文报道了基于小檗碱流通型传感器的电化学检测器用于含小檗碱中(成)药样品的流动注射分析,方法简便快速,结果准确可靠,样品分析速度可达120次/h。