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91.
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本文运用免疫细胞化学PAP及ABC法,显示大白鼠下丘脑内OXT免疫阳性神经元,并于垂体后叶注射WGA-HRP,显示下丘脑中逆行标记细胞,结合免疫细胞化学方法,观察下丘脑及其邻近区域内HRP与OXT双标记细胞,证实下丘脑视上核、室旁核、穹窿前核和后核、血管周细胞群、下丘脑视前区、下丘脑前区及外侧区、背侧副细胞群内、室周部、第三脑室侧壁室管膜细胞下及室间孔部室管膜细胞下,均有OXT免疫阳性神经元,其中至少部分神经元可发出向垂体后叶的投射纤维。位于第三脑室侧壁室管膜下及室间孔部室管膜下的神经元,可能监测脑脊液中各种因素的变化,调节垂体后叶OXT的分泌,也可能直接通过共树突向脑脊液内释放OXT。  相似文献   
93.
Mimicking cell membrane and the biomolecular recognition associated with membranes represents a great technical challenge, yet it has opened doors to innovative diagnostic and therapeutic methods. Our work has focused on design and synthesis of a class of smart materials exploiting biological principals for use in biosensors: these materials are functional polymeric assemblies that mimic the cell membrane and conveniently report the presence of pathogens with a color change. Biologically active cell membrane components are incorporated into conjugated polymers with desirable optical properties and the binding of the target molecules onto the material triggers conformational and electronic shifts that are reflected in a chromatic change (a so-called biochromic shift) that is conveniently observed and recorded. Langmuir–Blodgett thin films and vesicle bilayers provide ideal configurations for precise delivery of the biological binding entity to the sensing interface, and for control of molecular orientation for effective biomolecular interaction. Polydiacetylenic membrane-mimicking materials containing cell surface receptor gangliosides and sialic acid residues, respectively were formulated into these architectures and used for colorimetric detection of bacterial toxins and influenza virus. One advantage of these biochromic conjugated polymer (BCP) sensors is that their molecular recognition and signal transduction functionalities are resident in a single functional unit, making them amenable to convenient microfabrication and use.  相似文献   
94.
The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3+ T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6–15 h incubation at 37°C, the binding of RANTES, but not of macrophage inflammatory protein-1α (MIP-1α) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RANTES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4+ T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-1α, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-1α.  相似文献   
95.
Secretory immunoglobulin A (S-IgA) was investigated in human secretions for the presence of natural antibodies (Abs) acting as the first "immune barrier" to infection before induction or boosting of specific responses. These molecules could be the secretory counterpart of the natural Abs in serum that were previously shown by our laboratory to be polyreactive to autoantigens. Significant levels of S-IgA Abs to human actin, myosin, tubulin, and spectrin were detected in 10 saliva and 8 colostrum samples from normal subjects. Computer-assisted analysis of immunoblots of extracts from human muscles showed these Abs to react with a large number of autoantigens. Their polyreactivity was confirmed by cross-inhibition and by immunoblotting studies of affinity-purified natural Abs, assayed against a large variety of surface or secreted antigens from Streptococcus pyogenes. The thiocyanate elution method showed that functional affinities of some natural Abs can be of the same order of magnitude as those of tetanus vaccine antitoxins. Moreover, nonimmune binding of these natural Abs to the gut protein Fv (Fv-fragment binding protein) can enhance their effector functions. This demonstrates that human secretions contain polyreactive auto-Abs which can also react with pathogens. These secretory Abs of "skeleton key" specificities are possibly produced by a primordial B-1-cell-associated immune system and can be involved in a plurispecific mucosal protection against pathogens, irrespective of the conventional immune response.  相似文献   
96.
采用半固体一步单层琼脂培养法和单克隆荧光抗体技术分别观察重症肝炎外周血TL-CFU和mIL-2R,发现重症肝炎患者TL-CFU(104.4±32.6)及mIL-2R(35.6±8.6)较正常人明显降低。在培养体系中加胎肝细胞质液后,无论在重症肝炎组还是在正常组均不能明显地提高TL-CFU,说明胎肝细胞质液不含具生物佐的促TL-CFU因子。但对mIL-2R表达的影响,在重症肝炎组病人,只有在PHA存在条件下才能促进mIL-2R的表达,说明胎肝细胞质波含有某种(些)物质能协同PHA促进重症肝炎患者外周血淋巴细胞mIL-2R表达。  相似文献   
97.
股骨上端形态曲线的测量、参数化与统计分析   总被引:1,自引:1,他引:1  
通过对84根完好的中国人成人股骨标本进行正位和侧位两个方向的X线摄影,得到股骨正、侧两方位的X光片。对X光片上股骨上端髓腔内侧形态进行描绘,将描绘好的图像输入计算机,由计算机进行图像预处理后提取其曲线形态数据,并将形态数据参数化,从而得到可比较的、能准确表现股骨形态的量化数据,为股骨形态的分类分析和系列型人工髋关节的参数设计打下基础。  相似文献   
98.
本文报告了应用三种不同类型杀虫剂DDVP,残杀成和溴江菊酯点滴处理敏感株德国小蠊(Blattellagermanica)不同虫期后的药物敏感性以及带荚虫脱荚及其孵化情况。试验得出了不同虫期不同时间的LD50植和72h不同虫期对这3种药物敏感性的显著性测定(P值)的结果。发现不同虫期对这3种药物的敏感性之间关系的共同特点是:1.幼虫与雄虫敏感性差别显著(在DDVP和残杀威中)或者非常显著(在溴氰菊酯);2.雌虫与雄虫间差别在3种药物处理中均显著;3.雌虫与带荚虫在DDVP和溴氰菊酯处理中差别也非常显著。试验同时显示,3种药物不同浓度处理对德国小蠊脱荚及其孵化有十分显著的影响。其总的趋势是随着药物浓度的增高脱荚率明显地增加;相反,脱荚的孵化率则随着浓度的增加明显的下降。实验并得出脱荚的孵化与否和卵荚长度无明显关系。  相似文献   
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