cGMP对脑缺血再灌流后海马区星形胶质细胞活化的作用机制研究

为了观察 c GMP对海马区胶质纤维酸性蛋白合成调节的作用 ,本研究用钳夹沙土鼠的双侧颈总动脉制造脑缺血模型 ,进行了免疫荧光法染色。结果表明 :脑缺血再灌流后海马区 c GMP合成增加 ,多数 c GMP阳性细胞为星形胶质细胞 ,此细胞的多数呈 c GMP强阳性染色 ,胶质纤维酸性蛋白反应也多呈强阳性 ;使用鸟苷酸环化酶 ( GC)抑制剂 ODQ,则 c GMP合成减少 ,c GMP阳性细胞多呈弱阳性 ,同一细胞的胶质纤维酸性蛋白反应也多呈弱阳性。本实验结果提示 :c GMP可能与海马胶质纤维酸性蛋白的合成调节有关     

Mixed neuronal–glial tumor of the digestive tract: Distinctive entity from gastrointestinal stromal tumor?

A 53-year-old-woman presenting with pelvic discomfort was found to have a 9.5 cm tumor located in the wall of the ileon. Light microscopy showed that the tumor was made of fascicles of plump spindle cells and bizarre epithelioid cells. A cuff of lymphoid cells was also present at the tumor margin. The tumor cells strongly expressed tau protein, neuron-specific enolase, protein green product 9.5 and glial fibrillary acid protein (GFAP), but did not show positive immunostaining for S-100 protein, CD34 or CD117. The tumor showed unequivocal ultrastructural evidence of neural differentiation. Skeinoid fibers were scattered throughout the tumor. This is the first mixed neuronal-glial tumor of the digestive tract to be described in the literature. Such histological and immunohistochemical features could be misinterpreted as features of digestive schwannoma. We suggest that this tumor is distinct from gastrointestinal stromal tumors in lacking CD34 and CD117 expression.     

Expression of the 40 kDa catecholamine regulated protein in the normal and injured rat retina

Catecholamine regulated protein 40 (CRP40) has been shown to be expressed in the central nervous system (CNS) of several mammalian species where it may function in a similar manner to members of the heat shock protein (HSP) family. Immunohistochemical and immunoblotting techniques were utilized to investigate whether CRP40 is expressed in normal rat retinas. In addition, changes in CRP40 expression were studied following optic nerve transection. The immunohistochemical results showed that CRP40 is expressed in the normal rat retina. The protein was found to be highly expressed in the ganglion cell layer (GCL), the inner nuclear layer (INL) and the outer plexiform layer (OPL). In addition, a low level of CRP40 was found in the inner plexiform layer (IPL), and in the inner segment layer (ISL). No expression was found in the outer nuclear layer (ONL) of normal rat retina. The immunoblotting results show that CRP40 expression decreased in a time-dependent fashion after the optic nerve transection. This decrease indicates that the expression of CRP40 is dependent on the neuron's normal physiological state and that it plays an important function in physiological and pathological conditions in the retina.     

Alteration of the p53 gene of lung carcinomas with sarcomatous transformation (spindle cell carcinoma): analysis of four cases

Lung carcinoma with sarcomatous transformation (LCST) is highly aggressive and characterized by local invasion and/or distant metastasis, which leads to a shorter survival than ordinary lung carcinomas. Therefore, to elucidate whether the malignant potential of the spindle cell element in LCST is associated with the alteration of the p53 gene, four cases were examined by analyses of overexpression of the p53 oncoprotein, mutation of the p53 gene and loss-of-heterozygosity (LOH) at chromosome 17p. In two cases overexpression of the p53 oncoprotein of the spindle cell component showed a higher degree of staining than that of the carcinoma component; LOH was identified in both carcinoma and sarcomatous components in one case, while in contrast, another case showed LOH in the sarcomatous component only. Mutations were clearly detected in two cases; one showed a CTT to CGT transversion in codon 194 of exon 6 in both components, whereas the other showed a CTG to CAG transversion in codon 265 of exon 8 in the sarcomatous component only. On the basis of these observations, it suggested that the sarcomatous component shows a higher frequency of p53 gene abnormalities in comparison to the carcinoma component. These results also suggested that the acquisition of malignant potential in the sarcomatous component, or the morphological alteration of carcinoma cells, is correlated with abnormalities associated with the p53 gene.     

Growth of the human metatarsal bones in the fetal period (13–24 weeks postconception): a quantitative study

Summary We studied metatarsal growth in 600 metatarsal bones (60 pairs of feet) taken from 60 human fetuses (35 males and 25 females) ranging in age from 13 to 24 weeks postconception. The data obtained for the total length (TL) and for the ossified metatarsal length (OML) were correlated to fetal crown-rump length (C-R). The ossified metatarsal length presented a growth rate greater than the total length growth rate. There was no statistical difference between either the right and left metatarsals or males and females in total length and ossified metatarsal length growth during the period studied. We believe that metatarsal growth curves could be used to monitor fetal foot growth.

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Résumé Nous avons étudié la croissance métatarsienne sur 600 métatarsiens (60 paires de pieds) provenant de 60 foetus humains (35 masculins et 25 féminins) dont l'âge varie de 13 à 24 semaines après la conception. Les données concernant la Longueur Totale et la Longueur Osseuse ont été corrélées à la Longueur Vertex-Coccyx. La Longueur Osseuse a présenté un rythme de croissance plus rapide que la Longueur Totale. Il n'y avait pas de différences significatives pour la croissance de la Longueur Osseuse ou de la Longueur Totale ni entre les métatarsiens droits et gauches, ni entre les foetus masculins et féminins durant la période étudiée. Nous pensons que les courbes de croissance métarsienne pourraient être utilisées pour suivre la croissance du pied fetal.

     

Immunocytochemical localization of BGP in human bones in various developmental stages and pathological conditions

Summary Bone-carboxyglutamic acid containing protein (BGP) was isolated from human bone and anti-BGP antibody was produced in rabbits. Localization of BGP was investigated immunocytochemically by light and electron microscopy in human bones in various developmental stages and pathological conditions. In the bones of a 12 week fetus, osteoblasts stained strongly in areas of bone formation. However in bones of late fetal stages and in newborns and adults, BGP was localized predominantly in the osteoid and bone matrix in the ossifying front. Osteoblasts and osteocytes also stained positive, but less dominantly than in the early fetus. Electron microscopy showed that BGP was localized in the ER and Golgi cisternae of osteoblasts and osteocytes, and the collagen fibers of the osteoid and bone matrix. The intensity and distribution of staining were not significantly different in osteoporosis and osteoarthritis. These observations indicate that BGP is synthesized by osteoblasts most actively in early fetal life and is then deposited on collagen fibers of the osteoid and bone matrix.     

纳米壳聚糖纤维强化型磷酸钙骨水泥的研究

目的探讨纳米壳聚糖纤维强化型磷酸钙骨水泥的机械及生物相容性能。方法使用纳米壳聚糖纤维强化CPC骨水泥,通过MTT比色法及DAPI染色观察其生物相容性情况;通过三点弯曲试验检测其力学性能。结果三点弯曲试验表明经过壳聚糖纤维强化后的骨水泥的机械性能(17.3±4.5)MPa较之普通骨水泥有明显改善(5.3±1.4)MPa;并且这样的改进对材料的生物相容性没有影响,其毒性试验显示新材料相容性比值为(97.5±3.3)%。细胞增值实验3天吸光值分别为(0.237±0.025)、(0.451±0.015)、(0.726±0.032)。结论新型纳米壳聚糖纤维强化型骨水泥无细胞毒性,具有良好的机械性能及生物相容性。     

Characterization of EN4 monoclonal antibody: a reagent with CD31 specificity.

EN4 MoAb was originally described as a MoAb that reacts specifically with human endothelial cells, and the reagent was not assigned to any of the presently known CD. Here, we provide evidence indicating that EN4 reacts with the CD31 antigen. Thus, EN4 stains strongly murine fibroblasts transfected with the human CD31 gene. Furthermore, SDS-PAGE analysis of immunoprecipitates of cell lysates from surface-iodinated Jurkart T cells demonstrated that EN4 and reference CD31 MoAb recognized the same antigen, of 130 kD mol. wt. Finally, both EN4 and CD31 gave the same pattern of reactivity when tested on tonsillar or peripheral blood lymphoid cells by FACS analysis or by immunohistochemistry on sections of a variety of human tissues. EN4, however, proved consistently more efficient than the reference anti-CD31 MoAb as judged by both the intensity of fluorescence or of tissue staining. This property has thus allowed a better characterization of the tissue and cellular distribution of CD31.     

Modelling HA protein-mediated interaction between an influenza virus and a healthy cell: pre-fusion membrane deformation.

We present a mathematical model for pre-fusion interaction between an influenza virus and a healthy cell. Our model describes the role played by hemagglutinin (HA) protein clusters in bringing the viral membrane into close contact with the host cell membrane as a first step of the fusion process between the two membranes. The viral membrane is modelled as a lipid bilayer with bending rigidity. Using the calculus of variations, we compute the deformation of the viral membrane under the influence of HA protein clusters. Our numerical results support the hypothesis of dimple formation in the fusion site proposed in the literature. The asymmetric nature of the protein molecules due to various reasons such as tilting is the primary cause for the dimple formation. We discuss the effects of spontaneous curvature, the protein cluster radius, fusion-site size and the bending moment exerted by the protein cluster. We also examine the effects of membrane tension and the presence of a host cell on the dimple shape. Our results support previous experimental observations.