食管癌细胞膜提取物体外诱导胚胎胸腺细胞抗癌效应的研究

本文探讨增强胚胎胸腺细胞抗肿瘤效应的方法。采用食管癌细胞膜抗原体外诱导培养的胚胎胸腺细胞 ;用3 H TdR掺入法检测其对食管癌细胞的细胞毒效应 ;用SP 免疫组化法检测其经诱导后细胞表面抗原的变化。结果经食管癌细胞膜抗原诱导 3～ 9d的胚胎胸腺细胞对食管癌细胞的杀伤率明显大于未经诱导的胚胎胸腺细胞 ;胚胎胸腺细胞经诱导后CD4 + /CD8+ 细胞无明显变化 ,但诱导后出现少量CD5 6细胞。食管癌细胞膜抗原体外诱导胚胎胸腺细胞可增强其对食管癌细胞的细胞毒作用     

Cadherins in the central nervous system

The central nervous system (CNS) is divided into diverse embryological and functional compartments. The early embryonic CNS consists of a series of transverse subdivisions (neuromeres) and longitudinal domains. These embryonic subdivisions represent histogenetic fields in which neurons are born and aggregate in distinct cell groups (brain nuclei and layers). Different subsets of these aggregates become selectively connected by nerve fiber tracts and, finally, by synapses, thus forming the neural circuits of the functional systems in the CNS. Recent work has shown that 30 or more members of the cadherin family of morphoregulatory molecules are differentially expressed in the developing and mature brain at almost all stages of development. In a regionally specific fashion, most cadherins studied to date are expressed by the embryonic subdivisions of the early embryonic brain, by developing brain nuclei, cortical layers and regions, and by fiber tracts, neural circuits and synapses. Each cadherin shows a unique expression pattern that is distinct from that of other cadherins. Experimental evidence suggests that cadherins contribute to CNS regionalization, morphogenesis and fiber tract formation, possibly by conferring preferentially homotypic adhesiveness (or other types of interactions) between the diverse structural elements of the CNS. Cadherin-mediated adhesive specificity may thus provide a molecular code for early embryonic CNS regionalization as well as for the development and maintenance of functional structures in the CNS, from embryonic subdivisions to brain nuclei, cortical layers and neural circuits, down to the level of individual synapses.     

Sensitivity of mouse,rat, and human embryonic lungs to the action of nitrosomethylurea in organ culture

In response to the direct action of nitrosomethylurea (NMU) in a concentration of 0.05 mg/ml on organ cultures of embryonic lungs of strain A mice, Wistar rats, and man, a varied degree of degenerative changes and hyperplastic proliferation of the epithelium developed in the cultures. In the early stages of the experiment the toxic effect of the cultures predominated. Tissue of rat embryonic lungs was most sensitive to the toxic action of NMU, mouse lung tissue least sensitive. The frequency of hyperplastic proliferation, on the other hand, was highest in cultures of mouse lungs and lowest in cultures of rat lungs. During culture the sensitivity of the human and rodent embryonic lungs to the toxic action of NMU decreased when the substance was repeatedly added to the nutrient medium. Meanwhile an increase in the survival of the experimental cultures was observed compared with the intact control.Department of Carcinogenic Agents, Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR L. M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 349–352, September, 1977.     

Mg2+ reduces N-methyl-D-aspartate neurotoxicity in embryonic chick neural retina in vitro

N-Methyl-D-aspartate (NMDA) is a potent neurotoxin that affects cells in the inner layers of the embryonic chick retina exposed in vitro. After exposure of the embryonic day 12 neural retina to 0.5-10.0 mM NMDA for 30 min, 50-80% of the cells in the inner region of the inner nuclear layer and 50-100% of the cells in the ganglion cell layer were hypochromatic. When retinas were incubated with Mg2+ (0.5-10.0 mM) for 15 min and then incubated with Mg2+ and NMDA (0.5 mM) for 30 min, the NMDA effect in the inner layers was dramatically reduced but not abolished. Removal of Mg2+ before NMDA exposure produced retinas as seriously affected as retinas not exposed to Mg2+. Studying the effects of NMDA inhibitors, such as Mg2+, may help elucidate the mechanism of the cytotoxic events that occur in the retina in response to certain excitatory acidic amino acids.     

bFGF和EGF对胚胎神经干细胞分化为神经元及神经胶质细胞的影响

目的：观察碱性成纤维生长因子（bFGF）和表皮生长因子（EGF）对体外培养胚胎神经管神经干细胞生长和分化的影响。方法：从孕12天大鼠胚胎神经管分离神经干细胞，进行原代培养，分为bFGF组、EGF组、bFGF＋EGF组及对照组：培养过程中观察干细胞的生长，培养2小时做nestin染色鉴定神经干细胞，培养第5天用免疫组化方法检测培养细胞神经元特异烯醇化酶（NSE）和胶质纤维酸性蛋白（GFAP）的表达，以观察神经干细胞分化为神经元及神经胶质细胞的状况。结果：取材细胞大部分为nestin免疫阳性细胞；各实验组均可促进培养细胞的生长和分 化。免疫组化中，EGF使神经干细胞增殖成团，增加GFAP的表达（P＜0．01）；bFGF能明显增加NSE及GFAP的表达（P＜0．01）；两种因子联合应用，神经元和神经胶质细胞均比对照组增多（P＜0．01）。结论：EGF和bFGF两类生长因子均能促进胚胎神经干细胞的生长，在分化方面，EGF倾向于诱导干细胞增并向着胶质细胞分化，bFGF则诱导干细胞分 成更多的神经元。     

Emilin genes are duplicated and dynamically expressed during zebrafish embryonic development.

Emilins are a family of extracellular matrix proteins with common structural organization and containing a characteristic N-terminal cysteine-rich domain. The prototype of this family, Emilin-1, is found in human and murine organs in association with elastic fibers, and other emilins were recently isolated in mammals. To gain insight into these proteins in lower vertebrates, we investigated the expression of emilins in the fish Danio rerio. Using sequence similarity tools, we identified eight members of this family in zebrafish. Each emilin gene has two paralogs in zebrafish, showing conserved structure with the human ortholog. In situ hybridization revealed that expression of zebrafish emilin genes is regulated in a spatiotemporal manner during embryonic development, with overlapping and site-specific patterns mostly including mesenchymal structures. Expression of certain emilin genes in peculiar areas, such as the central nervous system or the posterior notochord, suggests that they may play a role in key morphogenetic processes.     

Developmental potential of embryos produced by in-vitro fertilization from gonadotrophin-releasing hormone antagonist-treated macaques stimulated with recombinant human follicle stimulating hormone alone or in combination with luteinizing hormone

We previously demonstrated, in luteinizing hormone (LH)-deficientmacaques, that follicular growth and maturation occurred withadministration of exogenous (recombinant human) follicle stimulatinghormone (r-hFSH) alone, and that the oocytes recovered fertilizedat a notably higher rate than their counterparts from animalsreceiving both r-hFSH and r-hLH (Zelinski-Wooten et al., 1995).Here, the developmental potential of embryos produced from animalstreated with r-hFSH alone or in combination with r-hLH was evaluated.Embryos (n = 127) were cryopreserved, thawed and either co-culturedon buffalo rat liver cells until the hatched blastocyst stageor transferred to synchronized recipients. Although embryosfrom each treatment group demonstrated a similar ability todevelop to hatched blastocysts with a definitive inner cellmass, a significant difference was seen in cryosurvival (56versus 78%) and in developmental rate to the hatched blastocyst(12 versus 10 days) between embryos from the r-hFSH alone andthe combination group respectively. Pregnancies resulted followingoviductal embryo transfers in both groups, with corpus luteumrescue occurring on days 12–16 of the luteal phase. Insummary, r-hFSH alone during the pre-ovulatory interval is adequatefor the gametogenic events required to produce embryos thatdevelop either in vitro or in vivo; however, exposure to r-hLHmay improve embryo viability and the rate of development.     

Photodynamic action of concanavalin A-chlorin conjugate e6 on human fibroblasts

Laboratory of Biomembranes, Institute of Applied Molecular Biology, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR I. P. Ashmarin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 109, No. 2, pp. 150–152, February, 1990.     

肝衰竭肝细胞移植治疗时的"种子细胞"

目前,对肝衰竭治疗主要依赖于原位肝移植,但这一治疗手段因存在多方面的困难而难以广泛开展。肝细胞移植的出现以其独特的优点将成为原位肝移植的辅助治疗甚至会替代原位肝移植。但是,肝细胞移植时最佳细胞来源的选择又成为我们面临的一个紧迫的课题,现用于研究的细胞来源多为骨髓干细胞(包括间充质干细胞和造血干细胞)、脐血干细胞及胚胎干细胞等,且在实验研究方面都取得了不同程度的研究进展。通过对这几种细胞分化为肝细胞的实验研究进展作综述,为肝细胞移植时“种子细胞”的选择打下理论基础。     

小鼠胚胎干细胞体外分化为神经前体细胞的研究

目的 探索小鼠胚胎干细胞（Embryonic stem cell,ES cell）体外分化为神经前体细胞（Neural precursor cells,NPC）的无血清培养条件,比较人胚胎成纤维细胞（Human embryonic fibroblasts,HEF）与小鼠胚胎成纤维细胞（Mouse embryonic fibroblasts,MEF）对小鼠ES细胞生长的作用。方法 在MEF或HEF饲养层上培养ES细胞,培养液中含白血病抑制因子。采用无血清方法培养NPC,免疫组化方法检测巢蛋白（Nestin）,用硝基四氮啖蓝/5-溴-4-氯-吲哚基磷酸（NBT/BCIP）显色检测碱性磷酸酶。结果 无血清培养可以获得86%的NPC。HEF与MEF-样能维持ES未分化状态。结论 无血清培养方法有利于ES细胞向NPC分化,HEF可用于小鼠ES细胞的培养,而且比MEF优越。