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关键词： Hypoxia   Development   Metabolic compensation   Heart rate  

摘要： Embryos of Austrofundulus limnaeus are exceptional in their ability to tolerate prolonged bouts of complete anoxia. Hypoxia and anoxia are a normal part of their developmental environment. Here, we exposed embryos to a range of PO2 levels at two different temperatures (25 and 30 A degrees C) to study the combined effects of reduced oxygen and increased temperature on developmental rate, heart rate, and metabolic enzyme capacity. Hypoxia decreased overall developmental rate and caused a stage-specific decline in heart rate. However, the rate of early development prior to the onset of organogenesis is insensitive to PO2. Increased incubation temperature caused an increase in the developmental rate at high PO(2)s, but hindered developmental progression under severe hypoxia. Embryonic DNA content in pre-hatching embryos was positively correlated with PO2. Citrate synthase, lactate dehydrogenase, and phosphoenolpyruvate carboxykinase capacity were all reduced in embryos developing under hypoxic conditions. Embryos of A. limnaeus are able to develop normally across a wide range of PO(2)s and contrary to most other vertebrates severe hypoxia is not a teratogen. Embryos of A. limnaeus do not respond to hypoxia through an increase in the capacity for enzymatic activity of the metabolic enzymes lactate dehydrogenase, citrate synthase, or phosphoenolpyruvate carboxykinase. Instead they appear to adjust whole-embryo metabolic capacity to match oxygen availability. However, decreased DNA content in hypoxia-reared embryos suggests that cellular enzymatic capacity may remain unchanged in response to hypoxia, and the reduced capacity may rather indicate reduced cell number in hypoxic embryos.

关键词： Apoptosis   Angiogenesis   Electron microscopy   Toothmesenchyme   Vasculogenesis  

摘要： Vascularization is essential for organ and tissue development. Teeth develop through interactions between epithelium and mesenchyme. The developing capillaries in the enamel organ, the dental epithelial structure, occur simultaneously by mechanisms of vasculogenesis and angiogenesis at the onset of dentinogenesis. The vascular neoformation in the dental mesenchyme has been reported to start from the cap stage. However, the mechanisms of vascularization in the dental mesenchyme remain unknown. In the hope of understanding the mechanisms of the formation of dental mesenchymal vasculature, mouse lower molar germs from embryonic day (E) 13.5 to E16.5 were processed for immunostaining of CD31 and CD34, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and transmission electron microscopy (TEM). In addition, the role of apoptosis for the vascularization in dental mesenchyme was examined by in vitro culture of E14.0 lower molars in the presence of the apoptosis inhibitor (z-VAD-fmk) and a subsequent subrenal culture. Our results showed that CD31- and CD34-positive cells progressively entered the central part of the dental papilla from the peridental mesenchyme. For TEM, angioblasts, young capillaries with thick endothelium and endothelial cells containing vacuoles were observed in peripheral dental mesenchyme, suggesting vasculogenesis was taking place. The presence of lateral sprouting, cytoplasmic filopodia and transluminal bridges in the dental papilla suggested angiogenesis was also occurring. Inhibition of apoptosis delayed the angiogenic vascularization of the dental papilla. Therefore, these data demonstrated that molar mesenchyme is progressively vascularized by mechanisms of both vasculogenesis and angiogenesis and apoptosis partially contributes to the vascularization of the dental papilla.

关键词： 兴趣   课堂效率   主动性  

摘要： 组织学与胚胎学是研究正常人体微细结构的医学基础课,理论内容比较抽象,难以理解。为了让学生对抽象枯燥的知识感兴趣,我们通过对多年教学过程的总结和和探索,总结出一套激发学生兴趣,寓教于乐的教学方法。通过此方法的实施,极大地提高了课堂效率,调动了学生的学习积极性,取得了良好的教学效果。

关键词： 实验学习   实验考评   解剖学与组织胚胎学   高职医学院校  

摘要： 《解剖学与组织胚胎学实验课学习与考评系统》是利用多媒体计算机技术,制作学习考核平台,植入实景实验室标本,形成实景标本—计算机—学习—考评模式,具有内容丰富多样、简便快捷,客观准确,学生乐于使用,能激发学生学习兴趣,提高学习效果等优点,是改进现行实验教学和考评手段的一条新途径。

关键词： 荧光原位杂交   染色体   自然流产   核型分析  

摘要： 目的发现自然流产组织染色体异常率及染色体异常类型,探讨自然流产的发生与胚胎染色体异常的关系。方法无菌条件下留取流产胚胎组织,同时进行细胞培养后核型分析和荧光原位杂交技术(FISH)检测。结果 136例流产胚胎组织染色体异常66例,异常率为48.53%;其中主要的染色体类型包括三体型30例(45.45%)、三倍体17例(25.76%)、单体型12例(18.18%)。结论胚胎染色体异常是导致自然流产发生的主要原因,在临床中有必要对自然流产组织进行染色体的检测。

关键词： 延安大学   硕士生导师   教研室主任   组织胚胎学   优秀教师   医学院   米脂县   获得者  

摘要： 苗乃周，男，汉族，1955年3月生，陕西米脂县人，教授，硕士生导师，延安大学教学名师，2011年宝钢教育优秀教师奖获得者。历任组织胚胎学教研室主任、延安医学院教务处处长、延安大学医学院院长兼陕北地方病研究院院长等职。

关键词： 人体胚胎学   高等职业教育   教材   人体组织学  

ISBN: (纸本)9787564147860

摘要： 本书对于实验教学的有效开展起关键作用。《组织学与胚胎学实训指导》既保持实训教学的系统性，每个实验都介绍了实验目的、实验材料、实验内容及方法等，又体现高职高专护理专业的特异性，增加相关思考题和填图，紧密联系护理临床。

关键词： Actin   Adhesion   Cytoskeleton   Membrane   Migration  

摘要： Background: The function of protein 4.1B in behaviors of motile cells remains poorly understood. Results: Deficiency of 130-kDa 4.1B resulted in impaired cell adhesion, spreading, migration, and stress fiber formation. Conclusion: Protein 4.1B plays an important role in modulating cell adhesion and motility. Significance: Our results identify a novel function for protein 4.1B and have implications for understanding the mechanisms of 4.1 function. Protein 4.1B is a member of protein 4.1 family, adaptor proteins at the interface of membranes and the cytoskeleton. It is expressed in most mammalian tissues and is known to be required in formation of nervous and cardiac systems;it is also a tumor suppressor with a role in metastasis. Here, we explore functions of 4.1B using primary mouse embryonic fibroblasts (MEF) derived from wild type and 4.1B knock-out mice. MEF cells express two 4.1B isoforms: 130 and 60-kDa. 130-kDa 4.1B was absent from 4.1B knock-out MEF cells, but 60-kDa 4.1B remained, suggesting incomplete knock-out. Although the 130-kDa isoform was predominantly located at the plasma membrane, the 60-kDa isoform was enriched in nuclei. 130-kDa-deficient 4.1B MEF cells exhibited impaired cell adhesion, spreading, and migration;they also failed to form actin stress fibers. Impaired cell spreading and stress fiber formation were rescued by re-expression of the 130-kDa 4.1B but not the 60-kDa 4.1B. Our findings document novel, isoform-selective roles for 130-kDa 4.1B in adhesion, spreading, and migration of MEF cells by affecting actin organization, giving new insight into 4.1B functions in normal tissues as well as its role in cancer.

关键词： Embryo   Nodal   Axis   Polarity   Mitochondria   Hypoxia  

摘要： The oral-aboral axis of the sea urchin embryo is specified conditionally via a regulated feedback circuit involving the signaling gene nodal and its antagonist lefty. In normal development nodal activity becomes localized to the prospective oral side of the blastula stage embryo, a process that requires lefty. In embryos of Strongylocentrotus purpuratus, a redox gradient established by asymmetrically distributed mitochondria provides an initial spatial input that positions the localized domain of nodal expression. This expression is perturbed by hypoxia, leading to development of radialized embryos lacking an oral-aboral axis. Here we show that this radialization is not caused by a failure to express nodal, but rather by a failure to localize nodal activity to one side of the embryo. This occurs even when embryos are removed from hypoxia at late cleavage stage when nodal is first expressed, indicating that the effect involves the initiation phase of nodal activity, rather than its positive feedback-driven amplification and maintenance. Quantitative fluorescence microscopy of MitaTracker Orange-labeled embryos expressing nodal-GFP reporter gene revealed that hypoxia abolishes the spatial correlation between mitochondrial distribution and nodal expression, suggesting that hypoxia eliminates the initial spatial bias in nodal activity normally established by the redox gradient. We propose that absent this bias, the initiation phase of nodal expression is spatially uniform, such that the ensuing Nodal-mediated community effect is not localized, and hence refractory to Lefty-mediated enforcement of localization. (C) 2013 Elsevier Inc. All rights reserved.