Immunohistochemical and immunoelectron microscopical characterization of cerebrovascular and senile plaque amyloid in aged dogs'' brains

Immunohistochemical and immunoelectron microscopical studies were carried out on 28 aged dogs' brains. Amyloid deposits were seen in the arteries and capillaries in the leptomeninges and in superficial areas of the cortices in 19 (67.9%) of the 28 dogs (10-22 years of age). Immunohistochemically, these amyloid deposits were reactive for anti-beta/A4 antibody. Additionally, a variable number of parenchymal deposits with diffuse beta/A4-immunoreactivity (diffuse plaques) was also noted throughout the cerebral cortex in 24/28 dogs (85.7%). However, these plaque lesions were undetectable in Congo red staining. Electron microscopically, amyloid fibrils, measuring 10 nm in width, were located mainly in the tunica media of the arteries, and in less involved vessels they tended to be present among collagen fibres in the adventitia and smooth muscle cells in the outer layer of the media. The plaque lesions appeared to contain sparse aggregations of amyloid fibrils. In immunoelectron microscopical examinations, all amyloid fibrils in both blood vessels and plaques were selectively labelled by gold particles. These findings indicate that aged dogs can provide a useful experimental model for research into the beta/A4-type of cerebral amyloidosis commonly seen in Alzheimer's disease.     

pp60c-src encoded by the proto-oncogene c-src is a product of sensory neurons

The advent of recombinant DNA technology has led to the identification in the DNA of normal animal cells of over 30 proto-oncogenes that are homologous to retroviral transforming genes. One of these encodes a protein kinase (pp60c-src) of unknown function, that is preferentially synthesized in brain and neural retina. Here the expression of pp60c-src in the peripheral nervous system was examined in sensory neurons from chick dorsal root ganglia with antisera raised against the transforming protein of Rous sarcoma virus (pp60v-src) expressed in Escherichia coli carrying the cloned v-src gene. This antiserum recognizes pp60c-src specifically in normal chicken cells. Western immunoblotting showed that dorsal root ganglia of stage 30 (day 6.5) chick embryos contained elevated levels of pp60c-src. Immunoperoxidase staining of neuron-enriched cultures prepared from chick dorsal root ganglia showed pp60c-src immunoreactivity in cells with neuronal morphology; flat, fibroblastic cells contained no detectable immunoreactivity. Indirect double immunofluorescence with pp60src antibodies and monoclonal antibodies against the 200-kD subunit of neurofilament protein confirmed that the cells expressing pp60c-src were neurons. Ninety-six percent of the neurofilament-positive cells were immunoreactive with pp60src antibodies, and conversely, all pp60c-src-positive cells were immunoreactive with neurofilament antibodies. pp60c-src immunofluorescence appeared to be distributed over the cell body, processes, and growth cones. These results clearly demonstrate that pp60c-src is a product of neurons and is expressed in sensory neurons in culture.     

Dissociation of GFAP intermediate filaments in EAE: observations in the lumbar spinal cord

Acute experimental allergic encephalomyelitis (EAE) in the Lewis rat is a cell-mediated autoimmune disease of central nervous system myelin. The lesion has been characterized by breakdown of the blood-brain barrier, edema, and periventricular infiltration of macrophages and lymphocytes. At the early stage of the disease, the astrocytes show a marked increase in immunostaining for glial fibrillary acidic protein (GFAP). A corresponding increase in GFAP content, however, cannot be demonstrated. Electron microscopic examination of the early lesion shows a typical reactive astrocytic response expressed by an enlarged watery cytoplasm, particularly at the level of the processes surrounding neurons and blood vessels and in the neuropil itself. The astroglial processes contain numerous glycogen particles (aggregates and single particles). Glial filaments are also conspicuous and are arranged in small bundles or loose thin filaments adjacent to the bundles. The glial filaments that normally appear as tight bundles have expanded and appear less dense. We suggest that the increase in GFAP immunostaining of the astrocytes in the early lesion is due in part to edema, which causes dissociation of the filaments and thereby exposes more antigenic sites to the antibodies.     

卡维地洛对不稳定型心绞痛患者血浆炎症因子的影响

目的观察卡维地洛对不稳定型心绞痛（UAP）患者高敏C反应蛋白（hs-CRP）、白介素-6（IL-6）及细胞间可溶性黏附分子1（sICAM-1）水平的影响。方法UAP患者62例采用完全随机化方法分成对照组（n=30）和治疗组（n=32）,在常规抗血小板、扩血管治疗基础上,对照组予美托洛尔（12.5mg,2次/d×3d）口服,治疗组服卡维地洛（6.25mg,2次/d×3d）,在治疗前后分别测定hs-CRP、IL-6、sICAM-1值。结果对照组和治疗组在治疗前hs-CRP、IL-6、sICAM-1均无显著性差异;用药后两组3指标均较用药前显著降低（P<0.05）;治疗组在用药后IL-6、sI-CAM-1显著低于对照组（P<0.05）。同时,用药后两组患者的心率、血压、心肌耗氧量均较用药前显著降低（P<0.05）,治疗组的心肌耗氧量显著低于对照组（P<0.05）。结论卡维地洛可显著降低UAP患者的炎症因子IL-6、sICMA-1水平。     

BMP7腺病毒基因转染对骨髓基质干细胞生物学的影响

目的 探讨BMP7腺病毒基因转染对骨髓基质干细胞(BMSCs)的体外、体内的生物学功能影响.方法 抽取羊的骨髓,分离、培养骨髓基质干细胞.用重组骨形成蛋白7腺病毒(adenovirus bone morphogenetic protein 7;Adeno-BMP7)转染(M.O.I=100)70%～80%融合时的第二代细胞,三天后分别进行透射电镜观察、流式细胞仪检测、Western-blot、钙结节染色以及珊瑚和细胞复合物皮下回植.结果 在体外:细胞超微结构观察显示Adeno-BMP7基因转染后的BMSCs的物质合成代谢功能活跃;流式细胞仪检测表明Adeno-BMP7基因转染对BMSCs的细胞周期无明显影响;Western-blot检测证明转染Adeno-BMP7后的BMSCs有BMP7在蛋白水平上的表达;染色表明转染Adeno-BMP7后的BMSCs可形成较大的钙结节.在体内:转染Adeno-BMP7的BMSCs可明显促进新骨的形成,与没转染Adeno-BMP7的BMSCs有差异.结论 Adeno-BMP7转染可促进BMSCs的体外成骨定向分化,Adeno-BMP7转染后的BMSCs具有更强的体内成骨能力.     

Effect of divalent cations on structure-function relationships of the antitumor protein α-sarcin

α-Sarcin binds one Zn(II) cation per protein molecule, with a K_d value of 0.9 mM, determined by equilibrium dialysis experiments. Ca(II), Mg(II), and Mn(II) do not bind to α-sarcin. Cd(II) and Co(II) also behave as Zn(II). The binding produces local modifications on the protein conformation affecting the microenvironment of tryptophan residues. The three cations modify the fluorescence emission of the protein. The near-u. v. circular dichroism spectrum of the protein is also altered. The binding of Zn(II) and related cations does not modify the secondary structure of the protein. The ribonucleolytic activity of a-sarcin is inhibited upon Zn(II) binding, but no alteration of the ability of the protein to aggregate phospholipid vesicles has been observed.     

Parvalbumin-immunoreactive neurons in the cerebral cortex of the lizardPodarcis hispanica

An antibody against the calcium binding protein parvalbumin selectively labels a set of neurons in the cerebral cortex of lizards. Golgi-like immunostained bipolar, multipolar and pyramid-like neurons appear mainly located in the inner plexiform layers. Parvalbumin-immunoreactive (PARV-IR) puncta are concentrated in the cell layer of the dorsal and dorsomedial cortices showing a basket-like distribution. The morphology and distribution of PARV-IR neurons and puncta overlap GABA-immunostaining in the cerebral cortex of lizards. Thus, it is likely that PARV-IR neurons are a subset of the cortical GABAergic neurons of lizards.     

瘦素、C-反应蛋白与老年急性冠脉综合征患者的相关研究

目的探讨急性冠脉综合征(ACS)患者血浆瘦素(LP)及C-反应蛋白(CRP)水平的变化及其临床意义。方法测定急性心肌梗死组(AMI组)、不稳定型心绞痛组(UA组)、对照组(健康体检者)血浆LP及CRP浓度,分析LP、CRP与病情严重程度的关系以及LP与CRP的相关性。结果AMI组、UA组患者血浆LP、CRP浓度较对照组显著升高(P<0.01),2组患者血浆LP与CRP浓度之间均呈显著正相关;AMI组血浆LP、CRP浓度比UA组明显升高(P<0.05)。结论血浆LP及CRP浓度与ACS病情严重性呈正相关,且LP与CRP浓度呈正相关。说明LP与CRP共同参与组织炎症反应,是ACS重要的危险因素及预测因子。