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关键词： Ameloblasts/metabolism   Animals   Brain/embryology   Brain/metabolism   DNA, Complementary/genetics   DNA-Binding Proteins   Embryonic and Fetal Development/genetics   Epithelium/metabolism   Extremities/embryology   Eye Proteins/biosynthesis   Eye Proteins/genetics   Fanconi Anemia/genetics   Fanconi Anemia/pathology   Fanconi Anemia Complementation Group A Protein   Fetal Proteins/biosynthesis   Fetal Proteins/genetics   Gene Expression Regulation, Developmental   Humans   In Situ Hybridization   In Situ Hybridization   Kidney/embryology   Kidney/metabolism   Liver/embryology   Liver/metabolism   Mesoderm/metabolism   Mice   Nerve Tissue Proteins/biosynthesis   Nerve Tissue Proteins/genetics   Odontoblasts/metabolism   Organ Specificity   Phenotype   Protein Biosynthesis   Proteins/genetics   Vibrissae/embryology   Vibrissae/metabolism  

摘要： About 80% of all cases of Fanconi anemia (FA) can be accounted for by complementation groups A and C. To understand the relationship between these groups, we analyzed the expression pattern of the mouse FA group-A gene (Fanca) during embryogenesis and compared it with the known pattern of the group-C gene (Fanca). Northern analysis of RNA from mouse embryos at embryonic days 7, 11, 15, and 17 showed a predominant 4.5 kb band in all stages. By in situ hybridization, Fanca transcripts were found in the whisker follicles, teeth, brain, retina, kidney, liver, and limbs. There was also stage-specific variation in Fanca expression, particularly within the developing whiskers and the brain. Some tissues known to express Fancc (eg, gut) failed to show Fanca expression. These observations show that (1) Fanca is under both tissue- and stage-specific regulation in several tissues;(2) the expression pattern of Fanca is consistent with the phenotype of the human disease;and (3) Fanca expression is not necessarily coupled to that of Fancc. The presence of distinct tissue targets for FA genes suggests that some of the variability in the clinical phenotype can be attributed to the complementation group assignment. (C) 1999 by The American Society of Hematology.

关键词： durum wheat   histology   morphology   somatic embryogenesis   AgNO3   Triticum durum Desf.  

摘要： Immature zygotic embryos of durum wheat cv 'Ardente' were cultured vitro on 2,4-D to induce somatic embryogenesis. Five days after culture initiation, somatic proembryos were directly initiated from the scutellum of immature embryos. After 28 days, somatic embryos were fully developed with a scutellum-like structure. Histological observations between the first and the eighty day in culture showed a clear unicelllar origin for a few of these somatic embryos, whilst most of them originated from a meristematic multilayer. Furthermore, estimation of the mitotic index of outer epithelium, subepithelium and inner epithelium of the scutellum during the first week of culture, showed a strict epidermal origin of these early developed structures. The addition of 1 mg . L-1 of AgNO3 enhanced the induction of direct somatic embryogenesis (a more than 22 fold increase), affecting both the percentage of embryogenic explants and the number of somatic embryos per explant, suggesting the possible involvement of ethylene.

关键词： 胚胎   肾   细胞学   形态学  

摘要： 用１３例人类胚胎标本研究了肾的组织发生过程。结果显示，３．５周时仅见由前肾管和前肾小管构成的前肾。５．５周时中肾已出现，由中肾管、中肾小管和肾小体构成。６～８周时中肾内可见到发育完好的肾小体和近端肾小管。５．５周时后肾原基已出现。６．５周时可见薄层被膜。１１周时可明显区分为皮质和髓质。７．５周出现肾小体，１２周可达３～５代，而且多半已发育至Ⅱ～Ⅲ期。１２周时各段肾小管开始分化。１６～１８周时肾小体多达７～８代，但皮质浅层即生肾区内仍可见到生后肾组织、后肾小泡和后肾小管。

关键词： 组织胚胎学   医学生   考试成绩  

关键词： 教材   神经系统   问题   建议   解剖学   组织胚胎学  

摘要： 本文针对全国中等卫校教材《解剖学及组织胚胎学》中“神经系统”一章的两个问题提出不同看法，并对“神经系统”的编写提出几点建议，与同仁磋商。

关键词： 胚胎脑移植   脑醒塞   治疗  

摘要： 胚胎脑组织块或细胞移植至皮质梗死区后,可以利用行为学试验检查移植大鼠的皮质高级感觉运动复合功能改善;应用形态学方法研究移植物的成活及其与宿主皮质各功能区建立的传入和传出纤维联系;利用电生理功能和递质分泌功能检查,判断移植物新生纤维的电生理功能和递质分泌功能。这些方法对于进一步研究胚胎脑细胞和组织块移植治疗皮质梗死具有重要的意义。

关键词： 蒙古绵羊   胚胎   心脏   组织发生   绵羊  

摘要： 蒙古绵羊早期胚胎的血岛是心管及血管组织发生的原基。交配后１２～１３日龄，在胚盘两侧的胚内中胚层内，首先发生血岛，进而扩展到原肠及尿囊的脏层。在１６～１８日龄，前肠腹面的心管，由单管状变形成Ｕ字袢，进而扭转成字形。因心管中段的收缩，出现心房、心室及动脉球三个膨大。２０～３０日龄，胚长４～１５ｍｍ，在房室管内，发生前后对称的心内膜垫，将房室管分隔成左及右房室口。由于心房内，第Ⅰ第Ⅱ房间隔发生，将心房分隔成左及右心房。再由于心室内室间隔的发生，将心室分隔成左及右心室。心管传导系统的窦房结，在１６～１８日龄，发生于静脉窦右侧心外膜下，此时心管的窦房部开始搏动。本文发现，在２１～２２日龄，胚长６～８ｍｍ时，静脉窦右侧心外膜下的窦房结细胞团散在。在房间隔壁内与心内膜垫相接处，房室结的细胞团群居。还发现，绵羊胚胎的心软骨原基，发生于３０日龄，胚长１５ｍｍ时，心软骨原基位于主动脉半月瓣外围水平上与肺动脉之间。

关键词： 蛇   胸腺发育   APUD细胞   胚胎发育   组织学  

摘要： 该文应用光镜、电镜和细胞计数技术对胚胎发育期虎斑颈槽蛇胸腺的发育分化进行了研究。在胚胎发育１１期，胸腺原基内出现前淋巴细胞。从胚胎发育１２期至出生前（１６期），淋巴细胞不断增殖分化，小淋巴细胞逐渐增多，而淋巴母细胞和中淋巴细胞逐渐减少。胸腺皮质和髓质形成于１６期。巨噬细胞以及肌样细胞和胸腺ＡＰＵＤ细胞分别形成于胚胎发育１４期和１５期，随后数量有所增加，分别分布于胸腺皮质和髓质。

关键词： Meckel憩室   卵黄囊   组织发生   卵黄管   组织胚胎学   有粒白细胞   淋巴器官   固有层   江西医学院   武山鸡  

关键词： 选择剪接   医学分子生物学   国家重点实验室   胚胎组织   剪接异构体   中国医学科学院   基础医学研究   小鼠   中国协和医科大学   cDNA