脑瘤占位的经颅多普勒(TCD)分析

近来,我们连续收治了12例脑瘤患者,均有CT证实,也都进行过详细的TCD检测。由于患者的脑瘤位置不一,脑瘤对血管的压迫程度各异。因此,TCD的结果也各有差异。尽管如此,他们还是具有共同的特征,即都有血管受压的TCD象征,如脑血管的流速降低,频谱波形异常,PI也有不同程度的偏高。所以,应用血液动力学的原理有可能推断出脑瘤的位置以及脑瘤压迫血管的严重程度。我们的初步经验认为,临床上在诊断脑瘤位置以及脑瘤压迫血管的严重程度方面,TCD可能成为一个有用的、非侵入性的方法。     

从腹泻患儿粪便中检出空肠弯曲菌

近年来,空肠弯曲菌在世界各国已成为引起腹泻的重要病原菌之一。1982年在我国上海首次报道后,各地已相继有报道。为了解空肠弯曲菌在我市儿童中发病情况和探索其病原特点,我院肠道门诊于1986年9月～1987年8月从549例腹泻患儿粪便中分离出12株空肠弯曲菌,其阳性     

中药三黄汤对家兔金黄色葡萄球菌R质粒消除的实验研究

中药三黄汤(黄苓、黄柏、黄连)作为R质粒消除剂,以家兔金黄色葡萄球菌作为靶细菌,进行R质粒的体外、体内消除实验。     

Relationship between Endopolyploidy and Cell Size in Epidermal Tissue of Arabidopsis

Relative quantities of DNA in individual nuclei of stem and leaf epidermal cells of Arabidopsis were measured microspectrofluorometrically using epidermal peels. The relative ploidy level in each nucleus was assessed by comparison to root tip mitotic nuclei. A clear pattern of regular endopolyploidy is evident in epidermal cells. Guard cell nuclei contain levels of DNA comparable to dividing root cells, the 2C level (i.e., one unreplicated copy of the nuclear DNA). Leaf trichome nuclei had elevated ploidy levels of 4C, 8C, 16C, 32C, and 64C, and their cytology suggested that the polyploidy represents a form of polyteny. The nuclei of epidermal pavement cells were 2C, 4C, and 8C in stem epidermis, and 2C, 4C, 8C, and 16C in leaf epidermis. Morphometry of epidermal pavement cells revealed a direct proportionality between nuclear DNA level and cell size. A consideration of the development process suggests that the cells of highest ploidy level are developmentally oldest; consequently, the developmental pattern of epidermal tissues can be read from the ploidy pattern of the cells. This observation is relevant to theories of stomate spacing and offers opportunities for genetic analysis of the endopolyploidy/polyteny phenomenon.     

Cellular Concentrations and Uniformity of Cell-Type Accumulation of Two Lea Proteins in Cotton Embryos

The levels and cell-type distribution of late embryogenesis abundant (Lea) proteins D-7 and D-113 have been determined in mature cotton embryos by immunochemical methods. The two proteins were expressed in and purified from Escherichia coli and utilized for antibody production in rabbits. The antiserum to each protein was found to interact with all members of each protein family in cotton extracts by protein gel blotting. Using these antibodies in quantitative "rocket" immunoelectrophoreses, D-7 proteins were found to accumulate to ~8 x 1015 molecules per embryo, which is equivalent to ~109 molecules per "average cell." D-113 proteins accumulate to ~1016 molecules per embryo, which equates to ~1.3 x 109 molecules per average cell. These values calculate to concentrations of about 226 and 283 [mu]M, respectively, in the cell aqueous phase immediately prior to seed desiccation. In immunocytochemical studies using the fluorophor rhodamine linked to the secondary antibody, both proteins appeared to be evenly present in the cytosol of all cell types present in the embryo, including both cotyledon and axis epidermal cells. Thus, their function does not appear related to unique functions of specific cell or tissue types. The very high molar concentrations of the two proteins, coupled with their unusual predicted structure and their cytosol location, would seem to reduce the number of their conceivable functions.     

Localization of the Functional p34cdc2 Homolog of Maize in Root Tip and Stomatal Complex Cells: Association with Predicted Division Sites

We have used an antibody against the functional homolog of the cdc2 kinase of maize to localize the p34cdc2 protein within dividing cells of the root apex and the stomatal complex of leaf epidermis. The microtubule cytoskeletal structure of plant cells was visualized concomitantly with a monoclonal antibody specific for [alpha]-tubulin. We found that the cdc2 protein is localized mainly to the nucleus in plant cells at interphase and early prophase. This finding contrasts markedly with the predominantly cytoplasmic staining obtained using antibody to the PSTAIRE motif, which is common to cdc2 and numerous cdc2-like proteins. In a subpopulation of root cells at early prophase, the p34cdc2 protein is also distributed in a band bisecting the nucleus. Double labeling with the maize p34cdc2Zm antibody and tubulin antibody revealed that this band colocalizes with the preprophase band (PPB) of microtubules, which predicts the future division site. Root cells in which microtubules had been disrupted with oryzalin did not contain this band of p34cdc2 protein, suggesting that formation of the microtubule PPB is necessary for localization of the p34cdc2 kinase to the plane of the PPB. The p34cdc2 protein is also localized to the nucleus and PPB in cells that give rise to the stomatal complex, including those cells preparing for the highly asymmetrical divisions that produce subsidiary cells. Association of the p34cdc2 protein with the PPB suggests that the cdc2 kinase has a role in establishing the division site of plant cells and, therefore, a role in plant morphogenesis.     

我国刺腿(虫脩)属一新种(竹节虫目:(虫脩)科)

自1977年以来,在我国陕西、四川、广西、广东等省陆续发现竹节虫严重为害林木和农作物。1986年四川省巫山县因竹节虫为害林木受灾面积达200余亩,山上的油桐、柏树、化香、乌桕、青冈及河边的麻柳等树叶被吃光,同时还为害玉米、马铃薯等。1989年在四川省忠县发现20余亩柏林被害仅剩光杆,一片黑褐色,状似火烧一样。在上述两地发     

棉铃虫多胚跳小蜂简报

<正> 棉铃虫多胚跳小蜂Litomasitix heliothisLiao是跳小蜂科多胚跳小蜂属的一种寄生棉铃虫的寄生蜂。过去在华北棉区未见记载。1992年华北麦田棉铃虫大发生,在河北饶阳发现该蜂的寄生率为9.2％,认为是一种值得重视的棉铃虫天敌。