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关键词： hypoxia   VEGF   coronary vasculogenesis/angiogenesis   quail  

摘要： Hypoxia is known to stimulate vascular growth by up-regulating vascular endothelial growth factor (VEGF), but little is known about the function of hypoxia in the development of the coronary vasculature, and the relationship between hypoxia and VEGF in this event. To test the effects of hypoxia and VEGF on coronary vasculogenesis/angiogenesis in the developing heart, ventricles from 6-day-old quail embryos were cultured on three-dimensional collagen gels. After 2 days of growth in normal medium and 1 day of starvation in low serum medium (0.5% fetal bovine serum), the heart explants were further cultured under various oxygen levels for another 24, 48, and 72 hr. Angioblasts and endothelial cells, which migrated out from the heart explants, mere identified by QH1 antibody using immunofluorescence and confocal microscopy. In the normoxic culture environment, the endothelial cells began to proliferate and migrate out from the heart explants after 3 days of growth;they formed tubes mainly after another 72 hr. In contrast, this vascular growth was accelerated under hypoxic conditions, as evidenced by increased tube formation with significant differences observed at 48 hr. On the other hand, hyperoxia delayed this process. Reverse transcription-polymerase chain reaction results indicated that VEGF (including VEGF(122), VEGF(166), and VEGF(190)) mas up-regulated in the heart explants under hypoxia and down-regulated under hyperoxia. VEGF neutralizing antibody added to the culture medium partially blocked this vascular growth. We conclude from this study that hypoxia can stimulate or up-regulate coronary vasculogenesis/ansogenesis and that VEGF signaling plays a major role in this event. Dev Dyn 1999;216.28-36. (C) 1999 Wiley-Liss, Inc.

关键词： FGF   FGF9   fibroblast growth factor   in situ hybridization   mouse development   gene mapping   gene structure  

摘要： Fibroblast growth factor 9 (FGF9), originally cloned as glial-activating factor from human glioma cells, is expressed in adult rat brain and kidney. Here we report the chromosomal localization, genomic organization, and embryonic expression pattern of the mouse Fgf9 gene. Fgf9 maps to chromosome 14 near the Ctla6 locus. The gene spans more than 34 kb and contains three exons and two introns. Translation initiation occurs in exon 1, and translation termination occurs in exon 3, Fgf9 RNA was detected during mouse embryogenesis in several tissues in which Fgf gene expression has not been previously described, including intermediate mesoderm of late-stage gastrulation, ventricular myocardium, lung pleura, skeletal myoblasts in the early limb bud, spinal cord motor neurons, olfactory bulb, and gut lumenal epithelium. Fgf9 is coexpressed with other Fgf genes in some skeletal myoblasts, in limb apical ectoderm, in craniofacial ectoderm, and in the retina, inner ear, and tooth bud. Dev Dyn 1999;216:72-88. (C) 1999 Wiley-Liss, Inc.

关键词： bromodeoxyuridine   cell death   cortex   fibroblast   growth factor   organotypic culture   subplate  

摘要： Subplate neurons form a transient layer immediately below the embryonic cortex and die early in postnatal life. It has been suggested that trophic factors, perhaps coming from cortical afferents, maintain the initial survival of these cells. Later withdrawal of these facto rs may cause subplate cell death. We tested whether basic fibroblast growth factor (bFGF) has survival-promoting effects on subplate cells in organotypic cultures from the late embryonic mouse cortex. We found that the survival of subplate cells was promoted by adding bFGF to the cu Itu res. By contrast, there was no effect of bFGF on the survival of overlying cortical neurons. These results indicate that bFGF may have a role in the regulation of subplate cell survival and death in vivo. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

关键词： 组织化学反应   低温保存   酶组织化学   保存期限   肝脏酶   大鼠   琥珀酸脱氢酶   非特异性酯酶   组织学与胚胎学   溶酶体  

关键词： FMR1   基因表达   选择剪接   胚胎组织   成人  

摘要： 选择剪接使单一基因表达产物的功能多样化,是真核基因表达调控的重要途径之一。FMR1基因在胚胎和成人不同组织中广泛表达,并在中枢神经系统等组织特异性高表达,转录本呈复杂的选择剪接方式。采用RT-PCR结合毛细管电泳分析了成人及2个6月龄胎儿10个组织中FMR1基因的选择剪接表达谱。FMR1基因在成人肺和肝组织中选择剪接表达谱相同,由7种选择剪接异构体组成;在胎儿不同组织中表达3种共同的主要剪接异构体,但这3种异构体在不同组织中所占比例及次要异构体剪接方式不尽相同。胎儿与成人组织中FMR1转录本剪接方式的主要差别表现在外显子12和17的使用上,提示FMR1基因的选择剪接表达存在发育转换。但在同一发育阶段的不同组织中未见FMR1选择剪接表达谱的显著改变。

关键词： 组织学   胚胎学   教学  

摘要： 组织学与胚胎学是一门形态科学。组织学主要讲授人体各器官、组织的光镜结构和电镜结构,内容微细零散;胚胎学则着重讲授人体胚胎发生和发育过程,通常“看不见”“摸不着”,且每一发育阶段都有形态、空间位置的变化。因此,本门课程教师不太好讲,学生也不容易理解和记忆,很?..

关键词： 人体胚胎骨髓   造血细胞发育   骨髓细胞   白血病  

摘要： 目的观察人体胚胎骨髓造血组织细胞的发生、发展规律，微环境的变化，以及对白血病诊断的意义。方法对９３例１～１０个月胚胎骨髓组织进行塑料包埋、半薄切片、Ｈ－Ｇ－Ｅ及组化染色观察。结果胚１月卵黄囊与羊膜囊周出现有核红细胞造血岛。胚２月软骨母细胞首先进入髓腔，骨髓微环境形成。胎３月骨髓出现各系各阶段造血细胞，胎儿期骨髓红粒比值始终倒置，以幼稚期血细胞为主，红粒系幼稚细胞成簇状聚集排列。胎５月骨髓出现脂肪，骨髓间质网纤与纤维细胞量少，中性粘蛋白为主。结论胚胎骨髓造血最早始于胚外中胚层的间充质细胞。胎３个月开始骨髓造血。软骨母细胞可能是髓内造血组织各种细胞的共同祖先，造血祖细胞是多源性的。胚胎期骨髓象类似髓性白血病。胎５月出现黄髓。组织结构变化比细胞形态变化对白血病的诊断更有指导意义。ＭＤＳ的诊断以髓索中央出现ＡＬＩＰ更确诊。

关键词： 组织胚胎学   医学院校   直观教学   结构与功能   讨论式教学   教学计划   人才培养模式   微细结构   及时复习   教学方法改革  

关键词： 蒙古绵羊   早期胚胎   静脉   组织发生  

摘要： 蒙古绵羊胚胎发育到１７ｄ、１７ｈ ，心房两侧有３ 对静脉原基发生，包括总主静脉，脐静脉及脐肠系膜静脉。胚胎发育到３０ｄ 龄，左总主静脉右移分化成冠状静脉。右总主静脉则分化成前腔静脉。３０ｄ 龄以后，左及右前主静脉间发生吻合，称左臂头静脉。左及右臂头静脉合并后汇总于前腔静脉。胚胎发育到２９ｄ 龄，后主静脉前段及中段退化，后段分化成总髂静脉。脐肠系膜静脉发生于卵黄静脉。胚胎发育到２０ ～３０ｄ 龄，在中肾的腹内侧发生左及右下主静脉间吻合。此吻合组成后腔静脉的肝部。在２４ｄ 龄以后，中肾背侧发生上主静脉。上主静脉接受总髂静脉，经上及下主静脉间吻合，再经腔皱襞汇入后腔静脉。

关键词： coculture   cumulus tissues   embryo morphology   in vitro fertilization   pregnancy rates  

摘要： Purpose: This study was undertaken to evaluate simplified methods of human embryo coculture using either attached or nonattached autologous cumulus tissue. Methods: Eight hundred one zygotes were cultured for 48 hr in a prospective, randomized trial comparing culture of embryos either with intact cumulus tissue, with cumulus tissue added to the droplet of culture medium, or without any cumulus tissue. In a follow-up study, embryo quality, pregnancy rates, and implantation rates were compared in 120 consecutive patients undergoing in vitro fertilization with a coculture system using cumulus tissue compared to a cohort of 127 patients undergoing IVF immediately preceding the institution of the coculture protocol. Results Embryo morphology was significantly improved (P < 0.05) following culture with attached cumulus tissue (5.61 +/- 0.29) and culture with added cumulus tissue (4.72 +/- 0.31) compared to that of embryos grown in culture medium without cumulus tissue (3.95 +/- 0.26). The clinical pregnancy rate improved from 39.4% (50/127) to 49.2% (59/120) following institution of a system of coculture with attached cumulus tissue. Conclusions: These data indicate that a simple coculture system using autologous cumulus tissue can result in improved embryo morphology, implantation rates, and clinical pregnancy rates during in vitro fertilization, This coculture system is simple, is non-labor intensive, and eliminates many of the risks which may be present in other embryo coculture systems.