云芝多糖对小鼠超氧化物歧化酶活力的影响(英文)

目的:研究云芝多糖(CVP,ip)对小鼠有关组织中超氧化物歧化酶(SOD)活力的作用。方法:实验在正常,荷瘤和~(60)Co-γ线辐射损伤小鼠中同步进行。SOD活力测定采用肾上腺素自氧化法。结果:CVP既能不同程度地增强正常小鼠和正常迟发型超敏感性(DH)小鼠淋巴细胞,脾及胸腺中SOD的活力,又能明显恢复或防止肿瘤或辐射对小鼠DH和淋巴细胞,脾及胸腺中SOD的抑制效应。CVP对肿瘤生长和肿瘤组织中SOD活力均有明显抑制作用。结论:CVP对小鼠SOD活性有促进作用,CVP的抗肿瘤和免疫恢复作用与其对SOD的作用有一定的联系。     

Postoperative radiotherapy and radiotherapy combined with CCNU chemotherapy for treatment of brain gliomas

A prospective, randomized trial evaluates the effects of two postoperative treatment regimens on survival in 198 adult patients with supratentorial gliomas. All patients were irradiated with 6 000 rads after possibly radical removal of tumors. CCNU administration in the dosis of 100 mg/sq m of body surface every 6–8 weeks following surgery proved to have no significant effect on the survival of patients. The median survival time in patients receiving radiation therapy alone was 61±7 weeks, while in those receiving additional chemotherapy was 56±4 weeks. Tumor histological malignancy and patients age were found to be the only important prognostic factors, irrespective of the treatment modality. Address for offprints: T Trojanowski, Department of Neurosurgery, Medical School, Jaczewskiego 8, 20-950 Lublin, Poland     

γ线照射对大鼠胃酸分泌及胃泌素释放的影响

本实验观察了大鼠全身照射不同剂量(4～25Gy)及全腹部照射(10Gy)后胃酸分泌的变化并用RIA方法测定照射后胃窦及血清中胃泌素水平.结果表明,全身8～25Gy照射后第3天,腹部10Gy照射后1～6周,胃酸分泌明显抑制.主现表现为胃液中[H~+]分泌的抑制,致使照射后胃液酸度降低.10Gy以上剂量照射使胃泌素释放增加,表现为血清胃泌素明显升高,胃窦胃泌素明显减少,导致照射引起的"低胃酸、高胃泌素血症".这种表现与人的某些萎缩性胃炎或恶性贫血的状况相似.     

Studies on mutants deficient in the photosystem I reaction centers in Chlamydomonas reinhardtii

Summary Genetic analysis of 25 nuclear mutants defective in the chlorophyll-protein complex CP1 was undertaken. The mutants belong to 13 complementation groups scattered throughout the nuclear genome. All these mutants lack the apoprotein of CP1 and, in addition, a specific set of six low molecular weight thylakoid polypeptides. System I particles obtained by treating WT thylakoid membranes with detergent specifically contain those polypeptides which the mutants lack. These observations suggest that a particular sub-structure of the thylakoid membrane associated with the photosystem I activity is missing from all 25 mutants studied, and that this general phenotype can result from mutation at any one of several unlinked Mendelian loci.     

Analysis of the subcellular localization of the proteins Rep, Rep' and Cap of porcine circovirus type 1

Porcine circovirus type 1 (PCV1) encodes two major ORFs. The cap gene comprises the major structural protein of PCV, the rep gene specifies Rep and Rep', which are both essential for initiating the replication of the viral DNA. Rep corresponds to the full-length protein, whereas Rep' is a truncated splice product that is frame-shifted in its C-terminal sequence. In this study, the cellular localization of PCV1-encoded proteins was investigated by immune fluorescence techniques using antibodies against Rep, Rep' and Cap and by expression of viral proteins fused to green and red fluorescence proteins. Rep and Rep' protein co-localized in the nucleus of infected cells as well as in cells transfected with plasmids expressing Rep and Rep' fused to fluorescence proteins, but no signal was seen in the nucleoli. Rep and Rep' carry three potential nuclear localization signals in their identical N-termini, and the contribution of these motifs to nuclear import was experimentally dissected. In contrast to the rep gene products, the localization of the Cap protein varied. While the Cap protein was restricted to the nucleoli in plasmid-transfected cells and was also localized in the nucleoli at an early stage of PCV1 infection, it was seen in the nucleoplasm and the cytoplasm later in infection, suggesting that a shuttling between distinct cellular compartments occurs.     

中医灸与人体穴位红外辐射光谱特性研究

本文通过锁相放大技术测到人体不到1cm^2面积的体表红外辐射光谱。通过对这些光谱的归一化处理后发现，不同人体和同一人体的不同穴位，尽管其红外辐射绝对光谱及强度相差很大，但归一化光谱都有相当的一致性与可比性。进一步将人体发射的平均归一化光谱与中医艾条灸、隔姜灸、隔蒜灸及隔附子饼灸点燃过程中的光谱比较发现，后面三种间隔灸与人体自发辐射的光谱有着惊人的一致性，而艾条灸等的光谱却相差甚远。     

Flat crossed-coil detector for blood flow measurement using nuclear magnetic resonance

A new flat crossed-coil nuclear magnetic resonance (n.m.r.) detector can be used to measure flood flow at many regions of the body, is introduced. It is compared, bothin vitro andin vivo, with the already proven cylindrical crossed-coil n.m.r. detector. Both detectors use a single high-field homogenous magnet. A single-sideband receiver reduces the effect of transmitter leakage into the receiver coil to allow the use of a high-level transmitter field. Preliminary application of the flat crossed-coil detector to the detection of cerebral blood flow is presented.     

Immunolocalization of lamins and nuclear pore complex proteins by atomic force microscopy

The nuclear envelope functions as a selective barrier separating the nuclear from the cytosolic compartment. Nuclear pore complexes (NPCs) mediate nuclear import and export of macromolecules and, therefore, are potential regulators of gene expression. In this study we applied atomic force microscopy (AFM) to visualize the three dimensional (3D) structure of individual NPCs in the absence and presence of two different antibodies, one directed against a pore protein (gp62) and another directed against Xenopus lamin LIII, a component of the nuclear lamina, a filament meshwork localized on the nucleoplasmic side of the nuclear envelope (NE) adjacent to and interacting with NPCs. Using 12-nm gold-labelled secondary antibodies and transmission electron microscopy we could clearly localize the primary single anti-gp62 antibody on NPCs and the primary single anti-LIII antibody between NPCs. Using AFM, the secondary antibodies against anti-gp62 could be detected as particles 7 nm in height on the nucleoplasmic face of NPCs. The secondary antibodies against anti-LIII could be clearly identified between NPCs. The secondary antibodies, attached to a 12-nm colloidal gold particle and visualized on glass, revealed similar shapes and heights as found on NEs. According to the 3D images, the volume of a single gold particle conjugated with secondary antibodies was 10 203 nm³. This volume is equivalent to the volume of 38 IgG molecules associated with one individual gold particle. A similar volume of 11 987 nm³ was calculated from a model assuming that the 150-kDa IgG molecules perfectly cover the spherical gold particle. We conclude that AFM can be used for identifying antibodies or other macromolecules associated with biomembranes.     

Role of H+ ions in volume and voltage of epithelial cell nuclei

Condensation of chromatin depends upon the ion composition in the cell nucleus. We tested in isolated nuclei of Madin-Darby canine kidney cells the influence of various ions on nuclear volume (i. e. DNA packing) and intranuclear voltage. After isolation, nuclei were superfused with cytosolic solutions in which Na⁺, K⁺, Ca²⁺ and H⁺ ions were varied. With video-imaging and microelectrode techniques nuclear volume and intranuclear potential were measured in response to the various ions. In control cytosolic solution, isolated nuclei exhibited an intranuclear electrical potential of –6.5±0.5 mV (relative to a reference electrode in the cytosolic solution) corresponding to a nuclear volume of 250±10 fl (n=104). Changing the Na⁺, K⁺ or free Ca²⁺ concentration in the superfusate in the physiological range resulted in minor changes of volume and intranuclear potential whereas pH altered both parameters dramatically. Nuclear swelling and intranuclear negative voltage increased with alkalinization and decreased when pH was reduced. An intact nuclear envelope was found to be no prerequisite for maintaining intranuclear negativity, indicating that the composition and functional state of nuclear chromatin rather than specific ion permeabilities of the nuclear envelope determine nuclear electrical potential. We present a model that explains nuclear volume and voltage on the basis of interaction between negatively charged DNA and positively charged histones of the nuclear chromatin.     

核辐射对机体的影响

机体受到一定剂量核辐射后会出现多个器官结构和功能的改变.本文综述了机体受到低剂量核辐射后出现的免疫细胞数量和功能变化,包括淋巴细胞总数和部分亚群数量、淋巴细胞转化率、血清免疫球蛋白含量以及单核细胞功能等变化.同时还综述了核辐射对内分泌及遗传的影响.