可口革囊星虫消化道的形态及组织学结构

对可口革囊星虫(Phascolosoma esculenta)消化道各部分结构进行了形态学和组织学观察,表明可口革囊星虫消化道由翻吻、咽、食道、肠、直肠和肛门组成。翻吻收缩性很强;肠道极长,沿纺锤肌螺旋缠绕成肠索。消化道管壁由内向外分为粘膜层、粘膜下层、肌层和外膜。粘膜上皮主要由柱状细胞组成。除肠外,消化道上皮细胞均有发达的纤毛,肠上皮细胞主要具发达的微绒毛;粘膜下层及肌层的发达程度因消化道的部位不同而异。     

金丝猴食管和胃连接部的组织学研究

本文研究了金丝猴食管和胃连接处的组织结构。金丝猴的食管粘膜为典型的复民鳞状上皮,食管末端含有粘膜腺,粘膜表面有轻微的角质化。管壁外纵肌层有少量的横纹肌。与胃粘膜的连接均位于胃的贲门部以内,两种上皮的连接是突然的,不存在过渡。 贲门腺为少量的分枝管状腺,短而直,由粘膜细胞构成,对PAS染色呈阳性反应。     

产毒性大肠杆菌毒素在豚鼠肠道定位的免疫组织化学研究

研究利用免疫组织化学方法对产毒性大肠杆菌（ETEC）感染豚鼠小肠组织中ETEC肠毒素的定位进行了研究,本研究结果表明,发病豚鼠从空肠到回肠明显充血,肿胀,但盲肠,结肠和直肠外观与对照组差别不明显,光镜下见到发病动物肠组织病变主要出现在空肠和回肠,以回肠最为严重。主要病理改变为水肿,炎症细胞浸润和充血,病变部位可以出现在粘膜层,粘膜下层,肌层和浆膜层,取回肠组织切片作免疫组织化学显示ETEC不耐热肠毒素（LT）和耐热肠毒素（ST）、可见回肠粘膜表层,粘膜肌层,肌层及浆膜层均呈LT和ST阳性反应,分布弥漫,空白对照和正常豚鼠回肠组织均呈阴性结果。本研究表明,ETEC主要作用于空肠和回肠,尤其是回肠;回肠组织各层都有病变,且与肠毒素的分布一致,证明毒素的作用并不仅限于肠粘膜细胞。     

溃疡病胃窦G和D细胞的体视学分析

应用真彩色医学院图像分析仪,对１５例ＤＵ、ＧＵ和ＣＯＮ组患者,非病变区胃窦粘膜,双重免疫组织化学显色的３００个Ｇ和Ｄ细胞进行形态学分析。每个细胞检测十二个参数。三组中,Ｇ细胞的周长、面积、长径、短径、比表面、平均截距、平均体积、平均面积、圆球度和平均直径数,在ＤＵ和ＧＵ组都发生改变,它们的显著性差异率分别为１００％;Ｄ细胞的长径、短径、形状因子和平均轴比数的改变,三组中的显著性差异率均在６０％以上,这些结果,进一步增加了溃疡病患者胃窦粘膜非病变区幽门腺Ｇ和Ｄ细胞的体视学形态计量学的参数资料,并提示它们参与了溃疡病的内分泌调控活动     

马拉硫磷对东亚飞蝗消化道影响的形态学观察

为探讨农药马拉硫磷对东亚飞蝗Locusta migratioria manilensis(Meyen)消化系统的影响,文中以喂食形式给药,不同喂食时间点蝗虫处死后固定、石蜡包埋、连续切片、HE染色并观察蝗虫消化系统不同部位形态学的病理变化。结果表明马拉硫磷对东亚飞蝗嗉囊、前胃、胃盲囊、中肠、回肠、结肠、直肠等各消化道部位均能造成明显的形态学改变,包括内膜完整性被破坏、上皮细胞死亡、纵肌、环肌、结缔组织等病变和坏死等,且呈时间依赖性。故马拉硫磷的作用可以影响到东亚飞蝗对食物贮存、研磨、消化、养分吸收的每一个环节,最终导致蝗虫的死亡。本文研究结果对蝗虫防治研究具有重要意义。     

白三烯与胃

大鼠及人的胃粘膜可释放白三烯(LT)。LT可引起胃蛋白酶分泌增多,胃粘膜血流量减少,影响胃的运动及降低跨胃电位差。乙醇引起的胃粘膜损伤与LT释放量增加呈平行关系。脂氧酶抑制剂等保护胃粘膜的作用与抑制LT释放有密切关系。脂氧酶抑制剂有可能成为一类有效的胃溃疡治疗药物。     

AS-Ⅳ对辐射损伤小鼠胃、十二指肠的防护作用

[目的]探究黄芪甲苷(AS-Ⅳ)对辐射诱导损伤的小鼠胃肠道是否具有防护作用。[方法]标准条件下饲养的100只昆明小鼠,根据实验要求分为对照组、DMSO组、辐射组、辐射+黄芪甲苷20 mg/kg组和辐射+黄芪甲苷40 mg/kg组,腹腔注射AS-Ⅳ一个月,以8Gy的~(60)Coγ辐射小鼠并采集胃、肠道组织,通过HE染色观察黄芪甲苷对辐射小鼠胃肠道形态学影响。[结果]与对照组相比,辐射组小鼠胃肠道损伤极其严重,胃粘膜层、粘膜下层、肌层与外膜损伤,结构改变;十二指肠粘膜、绒毛、腺体等发生病理变化,肌层外膜受损,甚至消失。黄芪预防组表明不同剂量的黄芪甲苷均对小鼠胃肠道辐射损伤具有一定保护修复作用。[结论]黄芪甲苷对辐射诱导损伤的小鼠胃肠道具有防护作用。     

小熊猫胃的解剖和组织结构研究

小熊猫的胃属单室腺型胃,它以角切迹为界,可分为胃底部和幽门部两部分。胃壁由粘膜、粘膜下层、肌层和浆膜四层组成。四上皮为单层柱状上皮,具有分泌粘液的功能。胃腺有贲门腺、胃底腺、幽门腺三种,但贲门腺不发达。主细胞、壁细胞和粘液细胞的数量与分布呈现规律性变化。肌层发达,特别是内环行肌发达。并与大熊猫胃的结构作了比较。     

大鼠浸水应激性胃粘膜损伤机制的研究

本工作观察了室温下单纯束缚加生理盐水,浸水应激加生理盐水,浸水应激加阿托品(0.5mg/kg),浸水应激加酚苄明(10mg/kg),浸水应激加戊巴比妥钠(30mg/kg)5组大鼠的胃粘膜损伤程度,胃酸分泌,胃壁结合粘液分泌和胃运动的变化。结果表明:大鼠浸水应激后胃粘膜损伤严重,胃酸分泌增加,胃壁结合粘液分泌减少,胃运动亢进;预先应用阿托品再浸水应激可显著减轻胃粘膜损伤程度,抑制胃酸分泌和胃运动,但增加胃壁结合粘液的分泌;预先应用应巴比妥钠亦显著减轻胃粘膜损伤程度,抑制胃运动和增加胃壁结合粘液的分泌,但对胃酸分泌无影响;预先应用酚苄明对胃粘膜损伤程度、胃酸分泌、胃壁结合粘液分泌和胃运动均无明显影响。上述结果提示,胃运动亢进、胃壁结合粘液分泌减少及胃酸分泌增加均不同程度地参与了浸水应激性胃粘膜损伤的形成,但在胃运动受到抑制及胃壁结合粘液分泌增加的情况下,仅胃酸的存在不致引起胃粘膜严重损伤。     

消化系统(1)——消化管电镜图象

图1.胃粘膜表面扫描电镜(SEM)图像:图为人胃粘膜表面,衬有单层柱状上皮细胞,且被纵横交错的小沟分为许多小区(胃区),整个胃粘膜分布着许多胃小凹(↑)。每一小的半球状隆起,为一柱状上皮细胞的顶部。×4,500 图2.胃粘膜纵断面SEM图像:图下方为粘膜表面,可见大量与粘膜表面呈垂直方向的胃腺。这些胃腺多呈单管状平行排列。Sm为粘膜下层。×300     

Light,electron microscopical,and immunocytochemical investigation of the stomach wall of the tigerfish Hydrocynus forskahlii

The wall of the stomach of the tigerfish is described and compared with that of other vertebrates. Light microscopic and ultrastructural characteristics of the stomach wall correspond to a large extent to those of other vertebrates, although some differences are found. The mucosa contains (1) surface epithelium characterized by narrow columnar cells with abundant mucous granules; (2) gastric glands consisting of pepsinogenic cells of variable height, containing tubulovesicles and bearing microvilli; (3) five granulated cell types located basally in the epithelium (types 1–5); and (4) lamina propria and muscularis mucosae. Connective tissue separating smooth muscle fibers of the muscularis mucosae constitutes a stratum compactum. The submucosa contains a loose connective tissue, a tunica muscularis of inner circular and outer longitudinal layers, and a serosa of mesothelium and subjacent connective tissue. Immunocytochemical tests with antisera to five polypeptides show gastrin/cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP) immunoreactivities in some cells of the gastric glands, and somatostatin in cells lying among epithelial cells lining the gastric luminal surface or gastric pits.     

袖状胃切除术Wistar大鼠模型建立及初步观察

目的探讨袖带胃切除术对Wistar大鼠体质量、大鼠前胃黏膜及黏膜肌层厚度的影响,为进一步研究袖状胃切除术的减重机制提供形态学依据。方法 20只雄性Wistar大鼠被随机分为2组,12只行袖状胃切除术做为手术组;8只行胃干预组做为假手术组,术前、术后第1天及术后1月内每周,而后每两周进行体重测量,术后12周处死大鼠后制作前胃石蜡切片,组织学方法观察其形态变化。结果手术组大鼠存活10只,成活率83%。假手术组大鼠在术后增重明显,手术组大鼠体重在术后2周恢复术前水平,体重增长明显但较假手术组慢（P〈0.05）。手术组大鼠术后前胃有代偿性扩张,光镜下可见黏膜及黏膜肌层厚度变薄,黏膜皱襞变浅。结论袖状胃切除术大鼠模型中对前胃的形态学观察可能有利于进一步阐明该术式大鼠模型的减重和体重反弹机制。     

Induction of EGFR tyrosine kinase in the gastric mucosa of diabetic rats.

Diabetes mellitus is associated with spontaneous gastric mucosal injury and enhanced susceptibility of the mucosa to damaging agents. Little information is available about the biochemical changes that occur in the gastric mucosa of diabetes mellitus. Evidence is accumulating that tyrosine kinases, particularly the EGF-receptor (EGFR), are involved in regulating a variety of structural and functional properties of the gastric mucosa. The primary objectives of this investigation were to determine whether diabetes induces morphological changes in the gastric mucosa, and if so, whether these changes are associated with alterations in EGFR tyrosine kinase. Diabetes-induced changes in gastric mucosal morphology were also examined. Diabetes was induced in 3- to 4-month-old male Fischer-344 rats by streptozotocin (STZ; 45 mg/kg; i.v.). Four weeks after induction of diabetes mellitus, the gastric mucosa of overnight-fasted rats was found to be slightly atrophic. A reduction in gastric mucosal thickness with deposition of fibrous tissue above the muscularis layer was observed in the stomach of overnight-fasted diabetic rats. These changes were associated with a marked stimulation in tyrosine kinase activity and protein expression of EGFR. The relative concentrations of several precursor forms of TGF-alpha in both membrane and cytosolic fractions from the gastric mucosa of overnight-fasted diabetic rats were also found to be significantly above the corresponding controls. This suggests that endogenous TGF-alpha may play a critical role in regulating mucosal EGFR tyrosine kinase through a juxtacrine/paracrine mechanism.     

Histochemical demonstration of mucins in the intramucosal laminated structure of human gastric signet ring cell carcinoma and its relation to submucosal invasion

Summary Thirty-one cases of signet ring cell carcinoma of the human stomach at an early stage were studied, employing a variety of histochemical techniques to characterize mucins and to elucidate factors accelerating the invasion of carcinoma beyond the muscularis mucosae. Signet ring cells were classified into six types largely depending on their histochemical reactivities. In 29 of 31 cases examined, the histochemical stainings detected the presence of characteristic mucins in an intramucosal laminated structure of proliferating carcinoma cells. The upper and lower layers of the typical intramucosal laminated structure consisted of carcinoma cells containing surface mucous cell and glandular epithelial cell-type mucins respectively; whereas the middle layer was occupied by immature carcinoma cells. Such a structure appeared to simulate cellular differentiations occurring in normal mucosa. The intramucosal laminated structure underwent structural distortion or disappeared, where submucosal invasion was evident. Ulceration appears to trigger the invasion beyond the muscularis mucosae.     

Localization of histamine and histamine H2-receptor antagonists in the gastric mucosa.

Synopsis Histamine stimulates acid secretion by the parietal cell and this secretion is inhibited by the histamine H₂-receptor antagonists. Whole body autoradiography showed that radioactivity from¹⁴C-histamine was localized in the artery walls of the stomach and in the muscularis mucosae, but that the level in the fundic mucosa was the same as the blood.When the H₂-receptor antagonists burimamide, metiamide and cimetidine were labelled with³⁵S,¹⁴C or³H and dosed to rats, whole body autoradiography showed that the stomach was predominantly labelled in the glandular mucosa from 5 to 120 min after administration. Microautoradiography in the rat and dog after intravenous injection of [³H] metiamide or [³H] cimetidine demonstrated an uptake of tritium in the parietal cell cytoplasm that was 3- to 4-times greater than that found in adjacent peptic cells or areas of muscularis mucosa. The preferential labelling persisted at a low level up to 6 h after injection in the rat. The localization of radioactivity from the H₂-antagonists in the parietal cell cytoplasm correlates well with their pharmacological activity in preventing acid secretion from this cell.     

Morphological examination of the termination pattern of substance P-immunoreactive nerve fibers in human antral mucosa

The termination pattern of substance P (SP)-containing axons in human antral mucosa was examined using immunohistochemical techniques at the light and electron microscopic level. SP-immunoreactive (IR) axons were found to extend towards the pit region of the glands, where intraepithelial axons were observed. Electron microscopy showed immunostained axon profiles in close contact with the basement membrane of surface mucous cells. Membrane-to-membrane contacts between labeled axons and myofibroblast-like cells were identified, and SP-IR axons that were apposed to the epithelium were also in contact with subjacent myofibroblast-like cells. The anatomical relationship between SP-IR axons and the cells of the muscularis mucosae was investigated by light microscopy. Immunoreactivity for alpha-smooth muscle actin (alpha-sma) was used to visualize the smooth muscle cells, and the alpha-sma-IR cells were found to create a network that surrounded the gastric glands. Immunostained varicose axons ran alongside and in close apposition to the labeled muscle strands. Ultrastructural examination showed close contacts between SP-IR axon profiles and smooth muscle-like cells. In conclusion, SP-containing neurons may be important for sensory and secretomotor functions in the human antral mucosa.     

ON THE PERMEABILITY OF THE STOMACH MUCOSA FOR ACIDS AND SOME OTHER SUBSTANCES

1. Solutions approximately isotonic with blood of strong and weak acids, several salts, glucose, and glycine were introduced in the resting stomachs of cats. The concentration and volume changes were recorded. 2. It was found that the stomach mucosa was permeable to the majority of the ions tested. There was also a permeability in the opposite direction from the blood (mucosa) to the stomach content, particularly of alkali chlorides. Poorly permeable substances were glucose, glycine, and sodium iodate. Pure weak acids such as acetic acid penetrated very rapidly. 3. The electrolyte concentration changes in the stomach content (or gastric juice) are pictured as an exchange diffusion; for instance, the hydrogen ions of an acid are exchanged against alkali ions of the mucosa or blood. 4. It is pointed out that the concept of the mucosa as an ion permeable membrane could be used as the foundation of a "diffusion theory," which can explain the acidity and chloride variations of the gastric juice without postulating neutralizing or diluting secretions.     

Calcitonin gene-related peptide neurons innervating the canine digestive system.

The pattern of nerve cells and fibers containing calcitonin gene-related peptide immunoreactivity (CGRP-IR) was investigated in the canine digestive tract by means of immunohistochemistry. CGRP-IR nerve fibers innervate all the layers of the gut, including the vasculature, with different densities depending on the region. CGRP-IR processes are sparse in the esophagus and stomach, where they are mostly confined to the enteric plexuses and vasculature. CGRP-IR fibers are quite abundant in the small and large intestine, where they form dense arborizations in the mucosa, and are numerous in the muscularis mucosae, deep muscular plexus and circular muscle. The myenteric and submucous plexuses of the intestine contain dense networks of CGRP-IR fibers and numerous CGRP-IR ganglion cells. On the other hand, in the enteric ganglia of the esophagus and stomach, in the intrapancreatic ganglia and in the ganglionated plexus of the gallbladder, CGRP-IR is restricted to non-varicose processes. A moderate density of CGRP-IR fibers supplies the endocrine and exocrine pancreas, and the fibromuscular layer and lamina propria of the gallbladder. The density of CGRP innervation in different regions can be summarized as follows: intestine > pancreas and gallbladder > or = antrum > cardia > gastric corpus and distal esophagus. CGRP- and tachykinin (TK)-IRs are colocalized in a substantial population of fibers, particularly those distributed to the mucosa, muscularis mucosae and vasculature, whereas there was no evidence of colocalization in intrinsic ganglion cells. The present results suggest that (1) the CGRP innervation of the dog digestive system includes an intrinsic and an extrinsic component, and (2) CGRP- and TK-IRs are co-expressed in extrinsic nerve fibers. These findings extend previous observations in rats and guinea pigs and provide insights into the sites of action of CGRP in the digestive system of the dog, which has served as a model for CGRP functional studies.     

Studies on 5'-nucleotidase histochemistry. III. 5'-Nucleotidase activity in smooth muscle cells of the rat's gastrointestinal tube.

The distribution pattern of histochemically detectable 5'-nucleotidase (5'-Nase) activity is described in smooth muscle cells of the rat's gastrointestinal tube (esophagus, stomach, small intestine, large intestine). Both, light and electron microscopic methods are used. Faint positive 5'-Nase activity is observed on smooth muscle cells of the lamina muscularis mucosae in the thoracal esophagus whereas it is completely absent from smooth muscle cells of the abdominal esophagus and the stomach. In the small and large intestine strong positive 5'-Nase reaction is found on smooth muscle cells of the lamina muscularis mucosae and the innermost part of the lamina muscularis externa. In the circular and longitudinal layer of the lamina muscularis externa a slight increase in 5'-Nase activity is observed from the proximal to the distal segments. The reaction product is restricted to the outer cell surface of smooth muscle cells. In the small intestine the strong enzymatic activity in the innermost part of the muscularis externa is found to be localized at small and dense muscle cells (sd-cells). Common morphological and histochemical characteristics of sd-cells and smooth muscle cells of the lamina muscularis mucosae are emphasized. Hypothetical functions e.g. uptake of precursors of nucleosidephosphates, possible functional connection to a high glycogen content, correlation between 5'-Nase activity and proliferation capacity and local vasodilatory effect are discussed.