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关键词： 教学策略   授导型教学   探究型教学   大体解剖学   微体解剖学  

摘要： 为探讨授导型教学和探究型教学两种教学策略在《解剖学及组织胚胎学》的应用效果,根据教材中不同的内容分别应用这两种教学策略进行了对照研究。结果表明:对于教材中大体解剖学内容采用探究型教学效果较好,而对于组织学内容宜采用授导型教学。从而表明在教师教学设计过程中,应根据不同教材内容灵活应用这两种教学策略。

关键词： VB循环程序   动画标签   自动组卷   自动阅卷  

摘要： 介绍了采用VB平台建立题库以实现医学图像考试自动组卷和自动阅卷的做法，指出该软件系统具有重复使用的特点，可自动生成符合教师要求的试卷，其试题数量和考试时间可由教师自行设定。

关键词： 预激综合征   Mahaim纤维   附加旁道   组织胚胎学   外科手术学   心电生理学   Kent束   射频消融  

摘要： 随着解剖学、组织胚胎学、心电生理学和外科手术学的进展,特别是射频消融在治疗中的应用,已确认预激综合征(WPW)的解剖基础是房室间除有正常房室结通道外,还存有附加旁道,其机制是激动经旁道预先激动心室。能够引起WPW的旁道有:Kent束、Mahaim纤维、James束,这3种旁道可有不同组合,构成10余种不同的类型及多种表现形式。[第一段]

关键词： chicken   egg   oxygen consumption   hypoxia   Hyperoxia   chorioallantoic membrane   lungs   ductus arteriosus  

摘要： During the first day of hatching, the developing chicken embryo internally pips the air cell and relies on both the lungs and chorioallantoic membrane (CAM) for gas exchange. Our objective in this study was to examine respiratory and cardiovascular responses to acute changes in oxygen at the air cell or the rest of the egg during internal pipping. We measured lung ((V)over dot(O2lung)) and CAM ((V)over dot(O2CAM)) oxygen consumption independently before and after 60 min exposure to combinations of hypoxia, hyperoxia, and normoxia to the air cell and the remaining egg. Significant changes in ((V)over dot(O2total) were only observed with combined egg and air cell. hypoxia (decreased ((V)over dot(O2lung) or egg hyperoxia and air cell hypoxia (increased ((V)over dot(O2total)). In response to the different O-2 treatments, a change in ((V)over dot(O2lung) was compensated by an inverse change in V-O2CAM of similar magnitude. To test for the underlying mechanism, we focused on ventilation and cardiovascular responses during hypoxic and hyperoxic air cell exposure. Ventilation frequency and minute ventilation (V-E) were unaffected by changes in air cell O-2, but tidal volume (V-T) increased during hypoxia. Both V-T and V-E decreased significantly in response to decreased P-CO2. The right-to-left shunt of blood away from the lungs increased significantly during hypoxic air cell exposure and decreased significantly during hyperoxic exposure. These results demonstrate the internally pipped embryo's ability to control the site of gas exchange by means of altering blood flow between the lungs and CAM. (c) 2007 Elsevier Inc. All rights reserved.

关键词： embryonic motor patterns   lobster   modulatory neurons   neural networks   stomatogastric nervous system  

摘要： Neuromodulatory inputs play important roles in shaping the outputs of neural networks. While the actions of neuromodulatory substances over the short term (seconds, minutes) have been examined in detail, far less is known about the possible longer-term (hours) effects of these substances. To investigate this issue, we used the stomatogastric nervous system (STNS) of the lobster to examine the short- and long-term effects of histamine on rhythmic network activity. The application of histamine to the entire STNS had strong inhibitory effects on all three of the STNS networks, observable within minutes. In contrast, longer-term (> 1 h) application of histamine induced the expression of a single, unified rhythm involving neurons from all three networks. Selective application of histamine to different regions of the STNS demonstrated that a unified rhythm arises following the long-term application of histamine to the commissural ganglia (CoGs;modulatory centres), but not the stomatogastric ganglion (site of neural networks). Strikingly, the single rhythm observed following the long-term application of histamine to the CoGs exhibits many similarities with the single rhythm expressed by the embryonic STNS. Together, these results demonstrate that histamine has markedly different short- and long-term effects on network activity;short-term effects arising through direct actions on the networks and long-term effects mediated by actions on modulatory neurons. Furthermore, they indicate that histamine is able to induce the expression of an embryonic-like rhythm in an adult system, suggesting that long-term actions of histamine may play key roles in the development of the STNS networks.

关键词： malignant fibrous histiocytoma   histogenesis   marrow stem cells   pluripotential mesenchymal   differentiation   rat-MFH specific antibody   MFH model   c-kit  

摘要： Malignant fibrous histiocytoma (MFH) is regarded as an undifferentiated pleomorphic sarcoma with unproven histogenesis. We investigated pathobiological characteristics of a rat MFH cell line (MT-9). Immunocytochemically, MT-9 cells and MT-9-induced tumours reacted to vimentin, A3 (rat MFH cell-specific antibody), macrophage markers and alpha-SMA (myofibroblastic marker), indicating that MT-9 showed both histiocytic and (myo)fibroblastic features. Adipogenic supplement-added MT-9 showed increased accumulation of lipid droplets. Addition of BMP-2 or osteogenic supplement to MT-9 enhanced osteoblastic markers (ALP activity, osteocalcin mRNA expression and calcification). TGF-beta 1-treated MT-9 revealed increased numbers of alpha-SMA-immunopositive cells, and enhanced protein levels of (alpha-SMA and fibronectin, indicating myofibrogenesis. In rat tissues, A3 labelled with immature mesenchymal and perivascular cells in foetuses and neonates, and with marrow stem cells in adults. c-kit mRNA expression was seen in bone marrows and MT-9. Collectively, progenitors of MFH should be sought in lineage of marrow stem cells capable of differentiating into mesenchymal cells. (c) 2007 Elsevier Ltd. All rights reserved.

关键词： embryonic stem cell   Rabbits   Laboratory mice   Human  

摘要： \We report here the development of a group of rabbit monoclonal antibodies against Smad1, Smad2, Smad3, and Smad5, and the immunocytochemistry (ICC) staining of human embryonic stem cells (hESC) and mouse embryonic stem cells (mESC). Eight New Zealand rabbits were immunized with synthesized peptides linked to KLH, and splenocytes from these rabbits were fused with rabbit immortal B cell 240E-W2. Resulting hybridomas producing anti-Smad monoclonal antibodies were screened by enzyme-linked immunosorbent assay (ELISA) with BSA-linked peptides. Clones were chosen for antibody production based on their activities in Western blotting and on paraffin-embedded human tissues, and the capacity of the antibodies in immunocytochemistry was demonstrated. Using these antibodies, we performed ICC staining on routinely cultured human and mouse embryonic stem cells, and showed that both cell types strongly express these genes. We propose that both hESCs and mESCs have the ability to transduce signals from both BMPs and TGFb/Activin.

关键词： in situ hybridization   mAb to Pl-nectin   mesenchyme cells   pigment cells   RT-PCR  

摘要： In the sea urchin embryo, primary mesenchyme cells (PMCs) are committed early in development to direct skeletogenesis, provided that a permissive signal is conveyed from adjacent ectoderm cells. We showed that inhibition of extracellular matrix (ECM)-ectoderm cells interaction, by monoclonal antibodies (mAb) to Pl-nectin, causes an impairment of skeletogenesis and reduced expression of Pl-SM30, a spicule-specific matrix protein. When PMCs are experimentally removed, some secondary mesenchyme cells (SMCs) switch to skeletogenic fate. Here, for the first time we studied SMC transfating in PMC-less embryos of Paracentrotus lividus. We observed the appearance of skeletogenic cells within 10 h of PMCs removal, as shown by binding of wheat germ agglutinin (WGA) to cell surface molecules unique to PMCs. Interestingly, the number of WGA-positive cells, expressing also msp130, another PMC-specific marker, doubled with respect to that of PMCs present in normal embryos, though the number of SM30-expressing cells remained constant. In addition, we investigated the ability of SMCs to direct skeletogenesis in embryos exposed to mAbs to Pl-nectin after removal of PMCs. We found that, although phenotypic SMC transfating occurred, spicule development, as well as Pl-SM30-expression was strongly inhibited. These results demonstrate that ectoderm inductive signals are necessary for transfated SMCs to express genes needed for skeletogenesis.

摘要： Retinoic acid signaling is critical for proper development, as well as the regulation of hematopoiesis in murine and human cells. It has been reported that retinoic acid expands definitive hematopoietic stem cells and confers an advantage in transplantation of murine HSCs. We demonstrate here that all trans retinoic acid (ATRA) blocks early hematopoiesis in zebrafish embryos as measured by decreased expression of scl and gata1. This loss of gata1 expression after exposure to ATRA is reminiscent of the lack of gata1 expression in cdx4 mutant zebrafish embryos, prompting the hypothesis that retinoic acid and cdx4 share a common signaling pathway regulating the emergence of the hematopoietic system, and that inhibition of ATRA might rescue blood development in cdx4 mutants. We tested 4-diethylamino benzaldehyde (DEAB), an inhibitor of retinoic acid biosynthesis, and AGN193109, a pan-RAR antagonist, for their ability to rescue gata1 expression in cdx4 mutant embryos. We found that treatment with either DEAB or AGN193109 results in increased gata1 expression in the posterior mesoderm of both cdx4 mutants and wild type zebrafish embryos. This rescue of gata1 expression in the cdx4 mutants is observed only when the DEAB treatment occurs during late gastrulation. Mutant embryos exposed to DEAB only during early gastrulation or somitogenesis did not have increased gata1 expression. While this observation may reflect the complex activity of ATRA in both hematopoiesis and in mesodermal patterning, we conclude that it is also consistent with a switch to the stimulatory effect of retinoic acid on hematopoiesis observed by others in adult mice. Similarly, DEAB treatment increased primitive

关键词： 神经干细胞   人胚胎   多巴胺能神经元   分化   帕金森病  

摘要： 目的体外培养人胚胎神经干细胞并诱导其向多巴胺能神经元分化。方法从临床引产的人胚胎（胎龄8~16周）海马组织中分离、培养人胚胎神经干细胞,对其进行诱导分化。诱导剂采用来源于20周胎龄胚胎的纹状体的组织提取液。实验分为2组：对照组无诱导剂,培养基为撤除生长因子的基础培养基;实验组培养基中加入纹状体组织提取液50μL/mL;于诱导分化的第7天终止诱导分化,采用标记TH的免疫荧光染色方法检测TH阳性细胞量,用RT-PCR方法检测TH-mRNA的表达情况。结果抗TH的免疫荧光染色结果为：对照组与实验组的TH阳性细胞率分别为（0.53±0.17）%和（7.38±0.84）%,两组相比差异有统计学意义（P〈0.05）。RT-PCR结果显示：对照组TH-mRNA表达不明显,实验组明显表达TH-mRNA,实验组与对照组的TH-mRNA表达差异亦有统计学意义（P〈0.05）。结论纹状体组织提取液具有促进人胚胎神经干细胞向多巴胺能神经元分化的作用。