Inhibition of in vitro lymphocyte blastogenesis by chicken alpha-fetoprotein

Chicken alpha-fetoprotein (ch-AFP), purified from fetal chicken serum and embryo extracts, respectively, was examined for its immunomodulatory effect in vitro. Significant (P less than 0.05) suppression of the allogeneic mixed lymphocyte reaction (MLR) was observed, when these preparations were added to one-way mixed lymphocyte cultures (MLC) in quantities of 62.5-1000 micrograms/ml. Suppression of the MLR was depending on the presence of ch-AFP for at least 16 h after initiation of the MLC, suggesting that this fetal protein was acting mainly in the early phase of lymphoblastogenesis. Serum of chicken embryos (12th and 15th day of incubation), day-old chickens, and of 10-week-old chickens of four different inbred lines were also found to exert suppression of the MLR. From these data, it is hypothesized that ch-AFP plays an immunoregulatory role by maintaining a certain stage of self tolerance during differentiation of the avian immune system.     

Comparative studies on dialyzable leukocyte extracts containing transfer factor—A review

The current state of knowledge concerning dialyzable leukocyte extracts (DLE) containing transfer factor (TF) is reviewed. Recent studies indicate that antigen-specific TF is an RNA-peptide component(s) of DLE that promotes antigen-specific cell-mediated reactivity (CMR). DLE also has nonspecific (adjuvant) activities both in vivo and in vitro. The term TF is now restricted to antigen-specific activity related to the promotion of dermal delayed-type hypersensitivity reactions and production of mediators of cellular immunity (lymphokines). Comparative studies of DLE containing TF activity in humans, non-human primates, and non-primates (cows) are discussed. Other animal models, including guinea pigs, dogs, mice, rats, and rabbits, are reviewed.     

Cell-mediated immunity in the dog in relation to disease: A review

Canine cell-mediated immunity and its in vitro testing is reviewed. Lymphocyte stimulation tests and the leukocyte migration inhibition test are discussed as corollaries of in vivo cell-mediated immunity. Cloning of progenitor populations, characterization of cell surface markers and DL-A typing for studies of canine immunity are also reviewed.     

齿轮转子-轴承传动系统的周期运动稳定性与分岔

建立了一个单级齿轮转子-轴承传动系统动力学模型,获得系统受到外部谐波激励时系统的周期响应,推导出系统n-1周期运动的四维Poincaré映射。利用Poincaré映射方法和数值仿真,对系统的稳定性与分岔进行分析,分析了系统n-1周期运动的Hopf分岔、周期倍化分岔及强共振情况下的亚谐分岔。研究了当分岔参数变化时碰撞振动系统由概周期碰撞运动向混沌运动的演化过程。通过对齿轮转子-轴承传动系统分岔与稳定性的研究,为工业实际中齿轮传动系统的优化设计提供了理论依据。