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41.
A pair of rat anti-mouse CD4 monoclonal antibodies (mAb) have been selected which bind to different epitopes of the molecule. Both the mAb are rat IgG2b and show clear synergistic activity in complement lysis in vitro. When injected together in vivo, they exhibit an improved immunosuppressive effect, compared to each antibody alone, on allogeneic graft rejection, humoral responses and on tolerance induction. Limiting dilution analysis indicates that the in vivo depletion of interleukin 2-producing cells is improved using both mAb by 2-3-fold over that obtained with the individual antibodies. As little as 60 ng per mouse of the CD4 antibody pair was sufficient to allow the induction of tolerance to human gamma-globulin, even without elimination of the CD4+ cells. The results suggest that appropriate antibody pairs may be good candidates for effective immunosuppressive serotherapy in man. 相似文献
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44.
Application of a micro-mechanics cell model to dentin composites for determination of their effective mechanical properties is discussed in this paper. The dilute micro-mechanics model for fibre-reinforced composites is utilized and the corresponding cell model is chosen to consist of a circular hollow cylinder filled with liquid or gas phase, which is surrounded by two circular cylindrical shells, a thin shell and a matrix phase. Each layer of cylindrical shell is here considered as a composite consisting of collagen fibrils, with mineralized hydroxyapatite, loosely connected to their neighbours, and water (or gas in the case of dry dentin composite). Determination of the effective material properties of such a three phase composite is discussed. Using the cell model the effect of porosity, thickness of each cylindrical shell, and mineral content on material properties is analysed. Results obtained from nano-indentation observations are compared with numerical predictions of the analytical model. 相似文献
45.
Individuals living in regions where malaria is endemic develop an acquired immunity to malaria which enables them to remain asymptomatic while still carrying parasites. Field studies indicate that cumulative exposure to a variety of diverse Plasmodium parasites is required for the transition from symptomatic to asymptomatic malaria. This study used a simulation model of the within-host dynamics of P. falciparum to investigate the development of acquired clinical immunity under different transmission conditions and levels of parasite diversity. Antibodies developed to P. falciparum erythrocyte membrane protein 1 (PfEMP1), a clonally variant molecule, were assumed to be a key human immunological response to P. falciparum infection, along with responses to clonally conserved but polymorphic antigens. The time to the development of clinical immunity was found to be proportional to parasite diversity and inversely proportional to transmission intensity. The effect of early termination of symptomatic infections by chemotherapy was investigated and found not to inhibit the host's ability to develop acquired immunity. However, the time required to achieve this state was approximately double that compared to when no treatment was administered. This study demonstrates that an immune response primarily targeted against PfEMP1 has the ability to reduce clinical symptoms of infections irrespective of whether treatment is administered, supporting its role in the development of acquired clinical immunity. The results also illustrate a novel use for simulation models of P. falciparum infections, investigation of the influence of intervention strategies on the development of naturally acquired clinical immunity. 相似文献
46.
我国正常生育力男子精浆的微量元素研究 总被引:12,自引:5,他引:7
本文报告测试了68例正常生育力成年男子精浆中的锌、铜,铁等微量元素和镁,测试结果如下:锌130±5.64μg/ml,铜1.84±0.158μg/ml,铁0.801±0.104μg/ml,镁103.86±10.01μg/ml。所测得的数值均在正常范围内。在正常范围内的精液,精浆中的锌、镁含量与精液质量(精子密度和活动力)之间无显著差异。但铜的含量与精子活动度关系密切,含量高则活动度差,反之则活动度好。铁的含量与精子密度关系也十分密切,含量高时精子密度也高。 相似文献
47.
Diabetes is the seventh leading cause of death in United States. Dietary intake and behaviors are essential components of diabetes management. Growing evidence suggests dietary components beyond carbohydrates may critically impact glycemic control. Assessment tools on mobile platforms have the ability to capture multiple aspects of dietary behavior in real-time throughout the day to inform and improve diabetes management and insulin dosing. The objective of this narrative review was to summarize evidence related to dietary behaviors and composition to inform a mobile image-based dietary assessment tool for managing glycemic control of both diabetes types (type 1 and type 2 diabetes). This review investigated the following topics amongst those with diabetes: (1) the role of time of eating occasion on indicators of glycemic control; and (2) the role of macronutrient composition of meals on indicators of glycemic control. A search for articles published after 2000 was completed in PubMed with the following sets of keywords “diabetes/diabetes management/diabetes prevention/diabetes risk”, “dietary behavior/eating patterns/temporal/meal timing/meal frequency”, and “macronutrient composition/glycemic index”. Results showed eating behaviors and meal macronutrient composition may affect glycemic control. Specifically, breakfast skipping, late eating and frequent meal consumption might be associated with poor glycemic control while macronutrient composition and order of the meal could also affect glycemic control. These factors should be considered in designing a dietary assessment tool, which may optimize diabetes management to reduce the burden of this disease. 相似文献
48.
目的探讨早期食管癌的组织发生学.方法对109例早期食管癌及癌周病变进行病理观察.结果其中20例的一点癌(黄豆大小),3例双原发癌,1例小细胞癌.癌周伴有不同程度的鳞状上皮异形增生和不典型增生.结论早期食管具有多样性生长的特点.提示临床医生在胃镜检查应注意多点取材,以防漏诊;以及正确确定手术范围,防止手术残留. 相似文献
49.
介绍了OPC(OLF for Process Control)技术及其在现场总线中的应用模式。给出OPC服务器的设计与实现的一种方法,并讨论了客户程序通过OPC服务器与现场设备的交互过程及OPC技术对现场总线的巨大影响。 相似文献
50.
Candida krusei发酵生产甘油过程中,菌体生长由玉米浆限制,菌体对玉米浆的得率为1.63g/g,培养其中玉米浆浓度相同时,增加渗透压或通过流加补料限制生长阶段的菌体生长,可使甘油生产阶段的比耗糖速率减慢,比耗糖速率保持在不很高的水平,可以因消耗的葡萄糖用于生长,维持,甘油和副产物形成所占比例的变化而提高甘油得率。 相似文献