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关键词： 组织胚胎学   实验教学   改革   实验教学改革   多媒体教学   多媒体技术   医学专业   机体细胞   基础学科   微细结构  

摘要： 组织胚胎学是医学专业中重要的基础课。是研究机体细胞、组织、器官微细结构及功能之间关系的基础学科。教学中只有把多媒体教学和传统的教学手段有机的结合起来,充分发挥多媒体技术在教学中的作用,才能达到提高教学质量的目的。

关键词： 组织胚胎学   多媒体课件   教学方法  

摘要： 组织胚胎学作为一门形态学学科,以研究人体的微细结构及其相关功能,个体发生、生长及其发育机理为主要内容.传统教学中多以挂图、模型、幻灯或投影为辅助教学工具,其选择面较窄、更新较慢,且多显示的是平面结构.多媒体课件的集成性、控制性、交互性,可弥补传统教学的不足[1～3].自2002年开始应用PowerPoint软件制作课堂教学课件并应用于教学,取得了良好的教学效果.

关键词： 多媒体教学   组织胚胎学   教学  

摘要： 目的探讨多媒体教学在组织胚胎学中的作用。方法分析组织胚胎学的特点,多媒体教学的优点和不足。结果组织胚胎学应用多媒体教学具有无可比拟的优点,但也有其不足。结论在组织胚胎学教学中, 多媒体教学应与传统教学相结合。

关键词： germination   Persea americana Mill.   protein bodies   reserve products   starch granules   zygotic embryogenesis  

摘要： Anatomical differentiation and storage product accumulation were studied during avocado (Persea americana Mill.) zygotic embryo development using histological techniques. The results were correlated with the germination capacity under in vitro conditions. The histodifferentiation phase, characterized by active cell division and differentiation, was accomplished by 100 d after pollination (DAP), when embryos reached 16-18 mm in length. After a phase in which there were no morphological changes, the maturation phase commenced at 125 DAP in embryos 24-26 mm in length. Accumulation of starch granules and the appearance of protein bodies occurred at this time. Germination was significantly influenced by the embryo developmental stage. Different parameters used as indicators of germination quality (germination percentage, germination speed and recovery of complete plantlets) showed a positive correlation with the age of the embryos. However, germination in vitro was not achieved fully until the end of zygotic embryo development, when the embryo reached physiological maturity.

关键词： embryonic stem cell   transplantation   6-OHDA lesion   Parkinson's disease  

摘要： We transplanted mouse embryonic stem (ES) cells pre-differentiated on a PA6 feeder cell layer into the striatum of 6-hydroxydopamine hemi-lesioned adult rats and studied the fate of the grafted cells 1 and 5 weeks post-grafting. At both time points, ES cell grafts contained tyrosine hydroxylase positive (TH+) and 5-HT immunoreactive cells. Between 1 and 5 weeks, there was an enlargement of the grafts and an increase in number of TH+ cells although the differences between the two time points were not significant. The mean number of TH+ neurons per striatum was 330 73 after 1 week and 1220 400 after 5 weeks. Over the same time period, mean soma profile area of the TH+ neurons increased significantly by 25.2%. Neurites were longer after 5 weeks (by 24.9%), but the difference to 1 week post-grafting was not reliable. The percentage of TH+ somata without neurites increased from 6.7% after 1 week to 38.3% after 5 weeks (not significant). After 5 weeks, two out of fifteen graft recipients had tumors indicating that pre-differentiation of mouse embryonic stem cells using this differentiation protocol is not sufficient to prevent tumor formation. (C) 2005 Elsevier B.V. All rights reserved.

关键词： DNA replication patterns   living cells   primary and immortalized cells   replication timing  

摘要： The extent to which chromosomal domains are reorganized within the nucleus during differentiation is central to Our understanding of how cells become committed to specific developmental lineages. Spatio-temporal patterns of DNA replication area reflection of this organization. Here, we demonstrate that the temporal order and relative duration of these replication patterns during S-phase are similar in murine pluripotent embryonic stem (ES) cells, primary adult myoblasts, and an immortalized fibroblast line. The observed patterns were independent of fixation and denaturation techniques. Importantly, the same patterns were detected when fluorescent nucleotides were introduced into living cells, demonstrating their physiological relevance. These data suggest that heritable gene silencing during commitment to specific cell lineages is not mediated by global changes in the sub-nuclear organization and replication timing of chromosome domains. (c) 2005 Wiley-Liss, Inc.

关键词： 农区   胚胎移植   受体牛羊  

摘要： 农区开展牛羊胚胎移植工作普遍存在着认识程度差、组织工作难到位、备用受体牛羊繁殖性能复杂、观察发情结果不准确、移植地点环境卫生条件不符合要求等诸多问题。我们针对以上问题,提出如下措施:(1)搞好计划,加大宣传,提高对胚胎移植技术要求的认识;(2)精心组织,合理分工,乡、村、组干部主要负责和农户的联络;放栓、打针受体要相对集中,由技术人员操作;抽栓和观察发情受体可相对分散,由农户本人操作;移植时受体必须集中到移植点,由移植人员操作;(3)制定备用受体标准,提高受体的利用率,对长期不发情或发情周期不正常、屡配不孕、习惯性流产的牛建议农户就诊或淘汰;(4)采用同步性较高的发情技术,减免受体的发情观察;(5)充分利用当地条件,合理建立胚胎移植点;(6)加强饲养管理,确保胚胎移植效果,移植后的受体牛羊应分圈饲养,增加营养,减少运动;应尽可能早地进行妊娠检查,以减少移植后受体的空怀时间。

关键词： 尿道下裂   临床治疗方法   常染色体显性遗传   外生殖器   尿道外口   阴茎下弯   先天性畸形   组织胚胎学   解剖学特征  

摘要： 尿道下裂是男性下尿路及外生殖器常见的先天性畸形,属常染色体显性遗传.据统计,在出生男婴中占0.4%－0.8%,组织胚胎学认为该病是由于胎儿在母体发育过程中尿生殖褶合并不良所致,尿道外口在阴茎下方形成尿道下裂.尿道下裂的解剖学特征主要有:①尿道外口异位;②阴茎下弯;③系带缺如。[第一段]

关键词： 多媒体技术   组织学与胚胎学   应用  

摘要： 如何在组织学与胚胎学教学中合理使用多媒体课件制作软件,根据笔者的教学实践,注意以下几点是很必要的. 1灵活利用多媒体技术 多媒体教学可以使组织学与胚胎学的教学内容、教学形式丰富多彩,使学生更容易接受一些难懂、抽象的知识.例如在讲授腺上皮的发生时,以前教师只是利用几张挂图讲述,腺上皮是由胚胎时期的被覆上皮向深部组织增生、迁移而形成的,腺上皮细胞增生后形成腺.这种讲授方法很抽象,学生不容易理解.

关键词： 人发角蛋白人工腱   生物力学特性   医学生物力学   组织学与胚胎学   重点实验室   组分材料   第一军医大学   降解吸收   力学指标   横截面积   人工腱植入   观察性研究   分子生物学   流行性疾病   缺损部位   功能部位   功能活动   观察对象   生物化学  

摘要： 背景:人发角蛋白人工腱植入肌腱缺损部位后,可被机体降解吸收,同时诱导机体形成新的自体腱。测定人发角蛋白人工腱及其组分的主要生物力学指标,以便根据人体不同功能部位需要选用合适的型号,使其具有人体进行功能活动所需要的拉应力。目的:测定人发角蛋白人工腱及其各组分材料的主要生物力学指标。设计:以人发角蛋白人工腱为观察对象,观察性研究。单位:一所军医大学的生物化学与分子生物学教研室、全军医学生物力学重点实验室,组织学与胚胎学教研室和佛山市康兴医学科技有限公司。材料:实验于2001-10在解放军第一军医大学全军医学生物力学重点实验室进行测定。人发角蛋白人工腱产品原料采自无地方流行性疾病、无环境污染的偏远山区,无染发、无烫发的健康女性黑发。人发经不同程度的生物力学处理获得3种在体内吸收速度递增的组分,Z,B和F。Z,B,F3种组分以一定的比例混合编结成各种型号规格的人发角蛋白人工腱。组分有3种型号规格,分别为Z3.0-20,B3.0-20,F3.0-20。人发角蛋白人工腱有6种型号规格:ZBF1.0-20,ZBF1.5-20,ZBF3.0-20,ZBF6.0-20,ZBF9.0-20,ZBF12.0-20。方法:将人发角蛋白人工腱或其组分材料的两端固定于MTS858生物力学试验机上,进行断裂拉力和拉应力指标的测定。主要观察指标:各种规格型号的人发角蛋白人工腱及其组分材料的断裂拉力和拉应力。结果:Z3.0-20,B3.0-20,F3.0-20组断裂拉力分别为(211.8±12.1,178.8±8.2,151.3±6.7)N,拉应力分别为(71.3±3.9,59.9±2.7,50.3±2.3)MPa,ZBF1.0-20,ZBF1.5-20,ZBF3.0-20,ZBF6.0-20,ZBF9.0-20,ZBF12.0-20各组断裂拉力分别为(75.0±3.0,107.8±4.2,194.1±5.3,375.9±12.7,508.2±21.3,670.8±25.4)N,拉应力分别为(75.0±3.0,72.0±2.8,65.1±1.8,62.9±2.2,56.3±2.4,55.8±1.5)MPa。结论:人发角蛋白人工腱的断裂拉力随横截面积增大而增大,拉应力随横截面积增大而略有减少。随着对人发处理程度的加剧,在体内被降解吸收的速度加快,相应组分的断裂拉力、拉应力减小。