凹耳蛙消化道组织学和嗜银细胞形态观察

为了揭示凹耳蛙(Odorrana tormota)消化道的基本特征,运用石蜡切片法和龙桂开银浸法对凹耳蛙消化道组织学结构及嗜银细胞的形态与分布密度进行了观察。结果显示:①凹耳蛙的胃壁具明显的纵行皱襞和胃小凹,胃腺发达,小肠可分为十二指肠和回肠,杯状细胞分散在十二指肠上皮细胞之间,十二指肠中未见十二指肠腺分布。②凹耳蛙嗜银细胞见于消化道全长,呈毛笔头样、锥体形、梭形、椭圆形和长条形等;幽门腺上皮和十二指肠绒毛上皮中的嗜银细胞具指向腺泡腔或肠腔的突起,提示其可能具有腔分泌的功能。嗜银细胞的分布密度胃幽门部最高,十二指肠和胃体其次,食道最低。据此认为胃既是凹耳蛙的主要消化器官,也是消化道中主要的内分泌器官;十二指肠是凹耳蛙消化道中的主要吸收部位,同时也具有内分泌功能;消化道嗜银细胞具有内分泌的功能,还可能具有腔分泌的功能。     

刺猬消化道嗜银细胞形态与分布

通过用龙桂开浸银法对刺猬消化道各段进行组织切片观察,结果表明嗜银细胞分布于胃贲门及以下所有消化管,其中胃、十二指肠与小肠末段嗜银细胞分布密度较高,小肠中段及直肠末段密度较低。嗜银细胞分布于消化管壁粘膜层腺体与绒毛,其中在腺体密度较高,在绒毛较低,并且胃、小肠壁固有膜腺体的中、底部密度最高,另外在胃幽门有狭小的高密度分布区。嗜银细胞有锥体形、瓜子形、椭圆形、长梭形、圆形等。锥体形、瓜子形、长梭形多有明显的长突起。嗜银颗粒或充满整个细胞,或集中于突起端或基底部。细胞外常可见到刚释放的嗜银颗粒,特别是锥体形、瓜子形细胞的尖端处常可见到向腺管腔或肠腔释放的嗜银颗粒。     

刺猥消化道嗜银细胞形态与分布

通过用龙桂开浸银法对刺猥消化道各段进行组织切片观察,结果表明嗜银细胞分布于胃贲门以及所有消化管,其中胃,十二指肠与小肠末段嗜银细胞分布密度较高,小肠中段及直肠末段密度较低,嗜银细胞分布于消化管壁粘膜层腺体与绒毛,其中在腺体密度较高,在绒毛较低,并且胃、小肠壁固有膜腺体的中、底部密度最高,另外在胃幽门有狭小的高密度分布区。嗜银细胞有锥体形,瓜子形,椭圆形,长梭形,圆形等,锥体形,瓜子形,长梭形多有明显的长突起。嗜银颗粒或充满整个细胞,或集中于起端或基底部,细胞外常见到刚释放的嗜银颗粒,特别是锥体形,瓜子形细胞的尖端处常可见到向腺管或肠腔释放的嗜银颗粒。     

中国黄羽鹌鹑消化道嗜银细胞胚后发育的分布及形态学观察

采用Grimelius银染法,对中国黄羽鹌鹑(Coturnix aponica)消化道嗜银细胞胚后发育的分布规律和形态结构进行了观察。结果显示,口腔、食管、嗉囊和泄殖腔中未发现嗜银细胞,其余部位均有不同数量的分布,其分布呈波浪形,大多数日龄段在腺胃和结直肠中存在2个分布高峰,回肠次之,十二指肠、空肠、盲肠较少,随着日龄增加,不同部位嗜银细胞数量均先增加,后减少,在100 d时达高峰。嗜银细胞主要分布在腺胃腺叶内细胞之间、肠黏膜上皮细胞之间及固有层内,形态多呈圆形、椭圆形、锥形及梭形等。结合嗜银细胞形态与功能间的联系,发现消化道内广泛分布着4种类型的嗜银细胞。我们认为中国黄羽鹌鹑消化道的嗜银细胞具有内分泌、外分泌及旁分泌3种功能,其分布特点可能与动物的食性及生活环境有关。     

巴西彩龟与无蹼壁虎消化道银染观察

为了探索爬行动物消化道内分泌细胞的分布规律和分泌类型,以改良龙桂开银染法对巴西彩龟、无蹼壁虎消化道嗜银细胞进行了观察,结果表明两种动物从食管到大肠都有嗜银细胞的分布,均在胃幽门或十二指肠有突出的分布密度高峰,在小肠末段或大肠始段有次分布密度高峰,巴西彩龟在食管还有第3分布密度高峰;嗜银细胞多数为毛笔头样、高脚杯状、锥体形、长梭形、椭圆形、不规则形等,多数嗜银细胞可见有明显的突起伸向管腔方向和向管腔释放分泌颗粒的现象,少数可见有伸向基膜或其周围的突起和向基膜或其周围释放分泌颗粒现象,这提示消化道内分泌细胞有闭合型和开放型两种,但更多的是开放型.     

白鹮胃肠道内分泌细胞的免疫组织化学定位

为了解白的消化生理过程 ,利用ABC免疫组织化学方法 ,对白胃肠道 5种内分泌细胞 :5 -羟色胺 (5 HT)、脑啡肽、P物质、胃动素和抑胃素的分布进行了研究。结果表明 :5 HT细胞主要分布于十二指肠及其以下部位 ,尤其是盲肠和直肠 ;而腺胃、肌胃和幽门中均未发现该类细胞。脑啡肽和P物质细胞数量明显较 5 HT少 ,它们稀疏分布于十二指肠及其以下部位 ,无显著的分布积聚区。抑胃素和胃动素在整个胃肠道中均无分布。分析表明白胃肠道 5种内分泌细胞的分布与其他鸟类相似 ,但与其他脊椎动物明显不同。     

红腹锦鸡胃肠道内分泌细胞的免疫组织化学定位

应用ABC免疫组织化学方法,对红腹锦鸡(Chrysolophus pictus)胃肠道5-羟色胺(5-hydroxtryptamine,5-HT)、胃泌素(gastfin,GAS)、生长抑素(somatostatin,ss)3种内分泌细胞的分布密度和形态进行了观察.结果显示,5-HT细胞在空肠和直肠分布密度最高,回肠和盲肠次之,十二指肠较少,腺胃和肌胃最少;GAS细胞在十二指肠和直肠分布密度最高,其次是空肠和盲肠,腺胃部最低,肌胃则呈免疫阴性;SS细胞数量较少,在直肠、盲肠处分布密度相对高,其次是十二指肠和空肠,腺胃部最低,肌胃则呈免疫阴性.3种内分泌细胞的形态多样,有圆形、椭圆形、锥体形、杆状和不规则形,其中以圆形、椭圆形为主.细胞分布于固有膜、黏膜上皮细胞基部、黏膜上皮细胞之间、腺泡上皮细胞基部或腺泡上皮细胞之间.红腹锦鸡胃肠道内分泌细胞的形态与其内、外分泌功能是相适应的.     

白yuan胃肠道内分泌细胞的免疫组织化学定位

为了解白yuan的消化生理过程,利用ABC免疫组织化学方法,对白yuan胃肠道5种内分泌细胞：5-羟色胺(5-HT)、脑啡肽、P物质、胃动素和抑胃素的分布进行了研究。结果表明：5-HT细胞主要分布于十二指肠及其以下部位,尤其是盲肠和直肠;而腺胃、肌胃和幽门中均未发现该类细胞。脑啡肽和P物质细胞数量明显较5-HT少,它们稀疏分布于十二指肠及其以下部位,无显著的分布积聚区。抑胃素和胃动素在整个胃肠道中均无分布。分析表明白yuan胃肠道5种内分泌细胞的分布与其他鸟类相似,但与其他脊椎动物明显不同。     

白xuan胃肠道内分泌细胞的免疫组织化学定位

为了解白xuan的消化生理过程,利用ABC免疫组织化学方法,对白xuan胃肠道5种内分泌细胞：5-羟色胺(5-HT)、脑啡肽、P物质、胃动素和抑胃素的分布进行了研究。结果表明：5-HT细胞主要分布于十二指肠及其以下部位,尤其是盲肠和直肠;而腺胃、肌胃和幽门中均未发现该类细胞。脑啡肽和P物质细胞数量明显较5-HT少,它们稀疏分布于十二指肠及其以下部位,无显著的分布积聚区。抑胃素和胃动素在整个胃肠道中均无分布。分析表明白xuan胃肠道5种内分泌细胞的分布与其他鸟类相似,但与其他脊椎动物明显不同。     

微流控芯片技术在细胞生物学研究中的应用进展

20世纪90年代以来,微流控芯片技术得到了快速发展。由于具有小型化、集成化、高通量、低消耗、分析快速等特点,微流控芯片作为一种新型的生物学研究平台,能够提供传统方法不具备的精细和可控制的细胞研究条件,在细胞生物学研究领域中得到了广泛关注。该文主要介绍其在细胞培养、分选、裂解、计数、凋亡检测、迁移、单细胞捕获、细胞间作用等方面的研究进展。     

Efficient and Innocuous Live‐Cell Delivery: Making Membrane Barriers Disappear to Enable Cellular Biochemistry

The confluence of protein engineering techniques and delivery protocols are providing new opportunities in cell biology. In particular, techniques that render the membrane of cells transiently permeable make the introduction of nongenetically encodable macromolecular probes into cells possible. This, in turn, can enable the monitoring of intracellular processes in ways that can be both precise and quantitative, ushering an area that one may envision as cellular biochemistry. Herein, the author reviews pioneering examples of such new cell‐based assays, provides evidence that challenges the paradigm that cell penetration is a necessarily damaging and stressful event for cells, and highlights some of the challenges that should be addressed to fully unlock the potential of this nascent field.     

Ultrastructural evidence for two-cell and three-cell neural pathways in the tentacle epidermis of the sea anemone Aiptasia pallida.

Sensory and ganglion cells in the tentacle epidermis of the sea anemone Aiptasia pallida were traced in serial transmission electron micrographs to their synaptic contacts on other cells. Sensory cell synapses were found on spirocytes, muscle cells, and ganglion cells. Ganglion cells, in turn, synapsed on sensory cells, spirocytes, muscle cells, and other neurons and formed en passant axo-axonal synapses. Axonal synapses on nematocytes and gland cells were not traced to their cells of origin, i.e., identified sensory or ganglion cells. Direct synaptic contacts of sensory cells with spirocytes and sensory cells with muscle cells suggest a local two-cell pathway for spirocyst discharge and muscle cell contraction, whereas interjection of a ganglion cell between the sensory and effector cells creates a local three-cell pathway. The network of ganglion cells and their processes allows for a through-conduction system that is interconnected by chemical synapses. Although the sea anemone nervous system is more complex than that of Hydra, it has similar two-cell and three-cell effector pathways that may function in local responses to tentacle contact with food.     

The role of glutamine, serum and energy factors in growth of enterocyte-like cell lines

Background: Glutamine is routinely added to most cell cultures. Glutamine has been found to be the preferential nutrient to the rapidly replicating intestinal mucosa, but whether this is a metabolic effect or due to other properties of this amino acid is not determined. To study the importance of glutamine on the growth of two enterocyte-like cell lines, the effects of depriving the media or supplementing it with glutamine were assessed in media with different serum and energy supplements. Methods: CaCo-2 and HT-29 cells were grown in serum-free medium, with fetal bovine or synthetic serum, and with or without glucose or galactose. The glutamine content was varied between 0 and 4 mM. All growth assays were performed in triplicate by counting in a hemocytometer. Results: Both cell lines were dependent of serum factors for growth, but displayed distinct requirements on glutamine supplementation. Glutamine was an obligate supplement with dose-dependent correlation to growth (r=0.87, p<0.01) for CaCo-2 cells cultured in synthetic, but not in fetal bovine serum. In HT-29 cells, the correlation between glutamine and growth was significant (r=0,68, p<0,05) only in fetal bovine serum in the absence of galactose. Conclusion: This study shows that glutamine has different growth stimulating effects on two enterocyte-like cell lines studied. This could reflect different modes of action of glutamine on proliferation and differentiation in an enterocyte cell population.     

哺乳动物体细胞核移植中供体细胞的研究进展

在哺乳动物体细胞核移植中,供体细胞是影响其效率的主要因素之一。供体细胞的类型、细胞周期、细胞的培养代数、冷藏与冷冻处理,以及供体动物的性别、年龄等都可能影响核移植胚胎的发育。根据现有资料,简要综述了在哺乳动物体细胞核移植中有关供体细胞的研究进展。     

微囊化K562细胞生长周期及代谢特性的研究

以K562细胞为模型,分别进行微囊化和游离培养,运用流式细胞术考察两种培养体系下细胞周期和生长代谢变化;建立数学模型,模拟了两种培养体系下细胞的生长活性和代谢特性。实验发现：微囊化培养过程中的K562细胞处于DNA合成期（S期）的百分含量显著高于游离培养,并且细胞保持较高的增殖活性。模型计算表明,所建模型动力学参数能够很好地描述微囊化和游离两种培养体系下细胞的代谢情况;对细胞活性的理论计算表明,微囊化的细胞具有较高的增殖和代谢活性,同时细胞能够较长时间保持此活性;模型参数表明,两种培养体系下,葡萄糖对细胞生长的影响无显著差别 (k^Free_L≈k^APA_L),乳酸对游离培养细胞的生长具有明显抑制作用,但对微囊化培养细胞抑制作用较小(kFreeL>≈kAPAL)。     

Of mice, frogs and flies: generation of membrane asymmetries in early development

Embryonic development begins with cleavage of the fertilized egg. Cleavage comprises two major processes: cytokinesis and formation of a polarized epithelial cell layer. The focus of this review is comparison of the generation of membrane polarity during embryonic cleavage in three different developmental model systems. In mammalian embryos, as exemplified by analysis of the mouse, generation of distinct membrane domains is uncoupled from cleavage divisions and is initiated in a specific developmental phase, called compaction. In Xenopus laevis embryos, generation of polarized blastomeres occurs simultaneously with cytokinesis. The origin of specific membrane domains of X. laevis polar blastomeres, however, can be traced back to oogenesis. Finally, in Drosophila melanogaster, generation of polarized cells occurs at cellularization. The relevance of cell adhesion, cell junctions and cytocortical scaffolds will be discussed for each of the model systems. Despite enormous morphologic differences, the three models share many common features; in particular, many important molecular interactions are conserved.     

Engineering Cardiac Cell Junctions In Vitro to Study the Intercalated Disc

Abstract

This review article discusses a recent work using engineered cardiac cells to study the function of the intercalated disc putting emphasis on mechanical and electrical coupling.     

Perivascular cells for regenerative medicine

Mesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and inflammatory diseases, although these cells remain heterogeneous and necessitate a better biological characterization. We and others recently described that MSC originate from two types of perivascular cells, namely pericytes and adventitial cells and contain the in situ counterpart of MSC in developing and adult human organs, which can be prospectively purified using well defined cell surface markers. Pericytes encircle endothelial cells of capillaries and microvessels and express the adhesion molecule CD146 and the PDGFRβ, but lack endothelial and haematopoietic markers such as CD34, CD31, vWF (von Willebrand factor), the ligand for Ulex europaeus 1 (UEA1) and CD45 respectively. The proteoglycan NG2 is a pericyte marker exclusively associated with the arterial system. Besides its expression in smooth muscle cells, smooth muscle actin (αSMA) is also detected in subsets of pericytes. Adventitial cells surround the largest vessels and, opposite to pericytes, are not closely associated to endothelial cells. Adventitial cells express CD34 and lack αSMA and all endothelial and haematopoietic cell markers, as for pericytes. Altogether, pericytes and adventitial perivascular cells express in situ and in culture markers of MSC and display capacities to differentiate towards osteogenic, adipogenic and chondrogenic cell lineages. Importantly, adventitial cells can differentiate into pericyte‐like cells under inductive conditions in vitro. Altogether, using purified perivascular cells instead of MSC may bring higher benefits to regenerative medicine, including the possibility, for the first time, to use these cells uncultured.     

Uniform straw-like cell architecture for three-dimensional cell–cell communication assay

ABSTRACT

We fabricated uniform straw-like cell architecture with central lumen using a suture thread within 1 h. The architecture consisting of cancer cells and mature adipocyte was used for cell–cell communication assay, although mature adipocyte could not form spontaneous multi-cellular spheroids. Using the system, it is possible to investigate three-dimensional cell–cell communication as an alternative to animal experiments.