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关键词： 胚胎干细胞   诱导分化   多巴胺能神经元   纹状体组织块  

摘要： 目的:探讨由胚胎干细胞向多巴胺能神经元方向分化的最佳诱导条件。方法:本实验采用纹状体组织块与胚胎干细胞联合培养的方法,通过形态学观察和酪氨酸羟化酶(TH)免疫细胞化学染色对分化细胞进行鉴定。结果:14%左右的胚胎干细胞诱导分化为多巴胺能神经元,而且分化神经元具有投射神经元的典型特征。结论:纹状体组织块不仅能诱导胚胎干细胞向多巴胺能神经元方向分化,还可影响轴突和/或树突的投射方向和分支模式。

关键词： 临床医学   专升本   《组织学与胚胎学》   课程   教学改革   医学教育  

摘要： 临床医学专升本教育是一种全新的高等医学教育模式,目前尚无成功经验可循.组织学与胚胎学是高等医学院校临床医学本科的主要课程之一,也是临床医学专升本的主要课程.人体组织学是一门重要的医学专业基础课,主要研究正常人体微观形态的空间构筑及其与功能的关系;人体胚胎学是研究人体个体发生、发育及其机理的一门学科,与临床各科、计划生育、优生优育有着密切的关系.使得本来就名词繁多的组织学和胚胎学更加抽象,因此,对临床医学专升本学生来说,在较短的时间里依照医学本科教育,体现出组织学与胚胎学的科学性、完整性和系统性,以达到临床医学专升本培养目标的要求.我们近三年来通过对99年级、2000年级、2001年级临床医学专升本组织学与胚胎课堂教学内容、学时比例、教学方法及教学手段进行了初步探索,并取得了一定的效果.

关键词： XENOPUS   OLIGOMERS   LITHIUM chloride   CENTRAL nervous system  

摘要： We analyzed the Chordin requirement in Xenopus development. Targeting of both chordin Xenopus laevis pseudoalleles with morpholino antisense oligomers (Chd-MO) markedly decreased Chordin production. Embryos developed with moderately reduced dorsoanterior structures and expanded ventroposterior tissues, phenocopying the zebrafish chordino mutant. A strong requirement for Chordin in dorsal development was revealed by experimental manipulations. First, dorsalization by lithium chloride treatment was completely blocked by Chd-MO. Second, Chd-MO inhibited elongation and muscle differentiation in Activin-treated animal caps. Third, Chd-MO completely blocked the induction of the central nervous system (CNS), somites, and notochord by organizer tissue transplanted to the ventral side of host embryos. Unexpectedly, transplantations into the dorsal side revealed a cell-autonomous requirement of Chordin for neural plate differentiation.

关键词： N-linked oligosaccharides   O-linked oligosaccharides   fucosidase   beta-elimination   peptide N glycosidase F   Xenopus embryogenesis   germ cells  

摘要： Previous works have shown that glycoconjugates with terminal fucose (Fuc) are located in the primordial germ cells (PGCs) of some mammals and might play a role in the migration and adhesion processes during development. The aim of this work was to identify the terminal Fuc moieties of Xenopus PGCs by means of three Fuc-binding lectins: from asparagus pea (LTA), gorse seed (UEA-I), and orange peel fungus (AAA). The histochemical procedures were also carried out after deglycosylation pretreatments: P-elimination with NaOH to remove O-linked oligosaccharides;incubation with PNGase F to remove Winked carbohydrate chains;and incubation with alpha(1,2)- and alpha(1,6)-fucosidase. The PGCs were always negative for LTA and UEA-I, two lectins that have the highest affinity for Fuc alpha(1,2)-linked. However, the PGCs were strongly labeled with AAA, which preferentially binds to Fuc with alpha(1,3) or alpha(1,4) linkages and to Fuc alpha(1,6)-linked to the proximal N-acetylglucosamine. There was fainter labeling with AAA when the sections were preincubated with a(1,6)-fucosidase, but the labeling remained strong when the sections were pretreated with alpha(1,2)fucosidase. When the beta-elimination procedure was carried out, the PGC labeling with AAA was slight. If the PNGase F incubation was performed, the PGCs remained moderately positive for AAA. These data suggest that the Xenopus PGCs have Fuc moieties in O- and N-linked oligosaccharides, including Fuc alpha(1,6) linked to the innermost GlcNAc, and that the Fuc was not in alpha(1,2)-linkage.

关键词： 冷冻解冻   红细胞   造血干细胞   胚胎   组织   冷冻保存  

摘要： 21世纪的医学将是各种新技术发明运用于医学的时代。细胞和组织的再生利用、手术的低侵袭性、高度重症病人的生活质量 (QOL)以及高龄者的医疗等等 ,这一切都与低温医学密切相关。本专辑将向读者全面展示有关低温生物学、低温医学的进展状况、基础理论、临床应用 ,值得各科医师和研究工作者一读。专辑选译自医学のあゆみ 2 0 0 2年第 2 0 1卷第 1 1期的特集———低温医学———新しい技术と临床应用。全集由大连医学情报研究所杨友竹教授主译。

关键词： 实验课教学   综合素质   医学院校   自学能力   组织胚胎学  

摘要： 随着科学的进步,社会的发展,医学模式的转变,医学院校应转变教育观念,建立起以学生为主体,教师为主导的新型教学关系,注重培养学生的终身学习意识和自学能力、实践能力、创新能力等综合素质.

关键词： 人胚胎无瘢痕愈合模型   组织学   创面愈合   瘢痕形成   模型建立   整形外科  

摘要： 创面愈合后瘢痕形成一直是困扰整形外科医师的临床难题，孕中期胎儿皮肤创面愈合后无瘢痕形成，成为人们期望的理想愈合方式，我们将孕中期人胎儿皮肤异种移植至裸鼠的皮下，建立人胎儿无瘢痕愈合的模型，并对其愈合过程进行了组织学观察，以期为人胎儿无瘢痕愈合机制的研究提供一定依据。

关键词： EMBRYOLOGY   ANOXEMIA  

摘要： Renewed interest in the use of the embryonic chicken as a model of perinatal cardiovascular regulation has inspired new questions about the control mechanisms that respond to acute perturbations, such as hypoxia. The objectives of this study were to determine the cardiovascular responses, the regulatory mechanisms involved in those cardiovascular responses, and whether those mechanisms involved the central nervous system (CNS) of embryonic chickens. Heart rate (fH) and blood pressure were measured in chicken embryos of different incubation ages during exposure to different levels of hypoxia (15, 10, and 5% O2). At all levels of hypoxia and at all developmental ages, a depression of fH and arterial pressure was observed, with the exception of day 20 embryos in 15 and 10% O2. The intensity of the embryonic fH and blood pressure responses were directly related to the level of hypoxia used. Muscarinic and alpha-adrenergic receptor stimulation limited the hypoxic hypotension on days 15-19 and 15-21, respectively, as indicated after blockade with atropine and phentolamine. During the final 3 days of incubation, the intensity of the hypoxic hypotension was magnified due to beta-vasodilation caused by alpha-adrenergic and muscarinic receptor stimulation. In 19- to 21-day-old embryos, the fH response to hypoxia was limited by alpha-adrenergic receptor stimulation as indicated by the accentuated bradycardia after blockade with phentolamine. Furthermore, on day 21, atropine limited the hypoxic bradycardia, indicating that muscarinic receptors also play a role in the fH response at this age. In addition, the muscarinic actions on the heart and the adrenergic effects on the vasculature appeared to occur through a hypoxic-induced direct release from chromaffin tissue and autonomic nerve terminals. Thus, in embryonic chickens, the only cardiovascular response to hypoxia that involves the CNS was the cholinergic regulation of arterial pressure after day 15 of incubation. Therefore,

ISBN: (纸本)7543920522

关键词： chick embryo   prolactin receptor mRNA   tissue distribution  

摘要： Serum prolactin increases during late embryogenesis. In order to elucidate the function of prolactin at this period, tissue distribution of prolactin receptor mRNA was examined by RNase protection assay. The mRNA was detected strongly in the kidney, intestine, and allantoic membrane;weakly detected in the brain;but not detected in the liver. The expression levels of the prolactin receptor mRNA in the kidney, intestine, and allantoic membrane were retained at constant levels during later stages of,embryogenesis: (Days 17 and 19) and posthatch periods (2 and 28 d after hatching). These results suggest that prolactin is mainly involved in the osmoregulation during the later stage,of embryogenesis and that the expression of prolactin receptor: mRNA in,the kidney, intestine, and allantoic membrane is regulated by a serum prolactin-independent manner.