大鼠坐骨神经分支选择性损伤后脊髓背角毛细血管和星形胶质细胞的反应

目的探讨成年大鼠坐骨神经分支选择性结扎切断(SNI)后,腰段脊髓背角内毛细血管和星形胶质细胞的反应。方法成年雄性SD大鼠40只,随机分为光镜组(n=30)和电镜组(n=10)。光镜组又分为对照组、假手术组和SNI手术组。SNI手术为分别结扎切断左侧胫神经和腓总神经,保留腓肠神经,存活20d。部分动物在术后经尾静脉给予30g/L伊文思蓝,切取脊髓L4平面,荧光显微镜观察伊文思蓝的渗出;另一部分在术后进行常规固定取材,切片进行抗鼠IgG和GFAP的免疫组织化学反应。电镜组(对照组和SNI后20d组),脊髓切片进行常规抗大鼠IgG的免疫电镜处理。结果 1.SNI后20d,可见明显的伊文思蓝渗出红色光斑;2.SNI后GFAP阳性细胞变为反应型,数量明显增加,毛细血管壁及其周围的IgG颗粒也显著增加。3.电镜观察:SNI术后20d,IgG阳性颗粒增多,内皮细胞观察到下列变化:(1)内皮细胞向管腔内伸出许多微细的突起,有的含有IgG阳性颗粒。(2)内皮细胞的管腔侧胞膜上有许多"内吞"小凹,凹内可见IgG阳性颗粒,胞质内有含IgG阳性颗粒的小泡,在反管腔侧胞膜上有"胞吐"现象。(3)内皮细胞紧密连接出现间隙,间隙内有IgG颗粒。(4)胞质内出现囊泡,有的泡内显示IgG阳性颗粒。结论 SNI后脊髓背角内毛细血管内皮细胞发生明显的反应,大鼠IgG和伊文思蓝可经过血脊髓屏障渗出,星形胶质细胞被激活。     

The effects of copper on actin and fibronectin Organization in Mytilus galloprovincialls haemocytes

The effects of copper on actin and fibronectin organization in Mytilus galloprovincialis haemocytes were studied. The Cu²⁺ exposure of mussels caused severe perturbations in haemocyte actin and fibronectin organization with respect to non-exposed organisms. Cytoskeletal actin was analysed by indirect immunofluorescence, using an antitotal actin monoclonal antibody, and by rhodamine-conjugated phalloidin. The majority of haemocytes from Cu²⁺-exposed mussels displayed a round morphology, with short and blunt filopodia; they lacked the polarized phenotype which was typical in control samples. The cytoskeleton alteration, more evident after phalloidin staining, resulted in the disappearance of filamentous actin. The actin cortical meshwork also appeared disorganized. The cytoskeletal morphology studied by transmission electron microscopy after negative staining of Triton X-100-treated haemocytes confirmed these observations. The structural organization of actin when analysed by Western blotting showed a larger number of Triton-soluble actin pools in treated mussel haemocytes. Fibronectin was studied by indirect immunofluorescence using a polyclonal antiserum directed against mussel fibronectin. In treated mussels, fibronectin appeared to be strongly disorganized and its levels decreased in both haemocytes and haemolymph. The mechanism(s) of the copper-induced alterations on actin and fibronectin organization in mussel immunocytes is discussed. Copyright     

一种具有超大颗粒的遗传性巨血小板减少症初步报告

目的研究具有异常超微结构的遗传性巨血小板减少症的血小板形态与功能。方法采集患者外周静脉血，分离富血小板血浆，用流式细胞术结合多种抗血小板膜糖蛋白（GP）单克隆抗体测定血小板膜GPⅠb、GPⅡb、GPⅢa、p-选择素和CD63的表达；分别以常规超薄切片术和免疫电镜技术检测患者血小板及其异常超微结构的性质；用荧光分光光度法测定血小板5-羟色胺含量。结果患者及其父亲血小板表面GPⅠb、GPⅡb和GPⅢa的表达正常，阳性细胞百分数及平均荧光强度与正常对照基本相同，但P-选择素和CD63的表达较高；两者血小板内均有数量不等的高电子密度大颗粒，有膜包裹，且有胞吐现象。该颗粒P-选择素、CD63反应均阴性，不是异常的α颗粒或溶酶体；患者及其父亲血小板5-羟色胺含量正常。结论报道一种具有异常超微结构的遗传性血小板减少症，血小板内异常的高电子密度非特异性超大颗粒可能代表了一种新的遗传性血小板病。     

高渗刺激诱导大鼠视上核与孤束核内神经元-星形胶质细胞复合体反应

目的 探讨大鼠接受高渗刺激后,视上核和孤束核内神经元-星形胶质细胞复合体(N-ASC)反应.方法 成年雄性SD大鼠50只,随机分为光镜组(n=40)和电镜组(n=10).采用多重免疫荧光标记法,在光镜下观察高渗刺激(9%氯化钠,5.5ml/kg尾静脉注射)后15、45、90和180 min,视上核内胶质纤维酸性蛋白(GFAP,标记星形胶质细胞)、催产素(OXT,标记视上核神经元)、Fos(标记神经元胞核)和孤束核内GFAP、酪胺酸羟化酶(TH,标记神经元)、Fos表达的时程变化.采用双重免疫电镜法,观察高渗刺激后视上核N-ASC内星形胶质细胞(用Cx43标记)与神经元(用Cx32标记)之间接触处的超微结构.结果光镜下在视上核和孤束核可分别观察到3种N-ASC,即:由 GFAP阳性星形胶质细胞与 OXT(或TH)阳性神经元形成的N-ASC;由GFAP阳性星形胶质细胞与Fos阳性神经元形成的N-ASC;由GFAP阳性星形胶质细胞与Fos和OXT(或TH)双阳性神经元形成的N-ASC.高渗刺激后 N-ASC的数量明显增加.抗Cx43和抗Cx32的双重免疫电镜显示,高渗刺激后Cx43阳性星形胶质细胞突起(即Cx43半通道)以及Cx32和Cx43形成的异型缝隙连接(HGJ)的数量明显增加.结论视上核和孤束核内的N-ASC参与渗透压调节反应.