Ultrastructural organization of the surface epithelium of gastric mucosa in vitamin A deficiency

Under conditions of experimental A-avitaminosis in cells of superficial epithelium of the chicken stomach mucous membrane certain ultrastructural changes of cytoplasmic membranes takes place. Amount of transport vesicles decreases, regeneration of membranes in the Golgi complex cisterns, secretory vesicles and apical part of the external cellular membrane with development of apical erosions is disturbed. The problem on influence of the changes mentioned to the process of mucus formation, in particular to protein glycosylation in the Golgi complex is discussed. Insufficient vitamin A amount, getting into the organism results in a decreased resistivity of the stomach mucous membrane as a consequence of disturbances in processes of mucus formation and in safety of the apical part of the external cellular membrane of the superficial epithelium.     

Ultrastructural changes in the proper layer of the mucous membrane of the duodenum following general gamma-irradiation]

The work has been performed on mature male Wistar rats which were irradiated in a "Gamma-Sell-220" apparatus in the dose of 1000 r, with thepower 42 r/sec. It has been shown that in early terms after irradiation (1-6 hours) slightly pronounced destructive changes were observed in cellular and fibrous structures of the stroma of theproper layer of the duodenum membrane in addition to pronounced exudative changes. Further, the latter increased and became maximum within 24 hours. The edema extends into the basal part of enterocytes and between the stroma cells giving rize to desorganization of all mucous membran elements. Seventy two hours after irradiation the destructive changes in cellular and fibrous structures of the mucous membrane layer proper became predominant. The authors make a conclusion that the changes in the stroma aggravate dysfunction of the epithelium injured by the irradiation energy.     

Scanning electron microscopic study of the oesophageal mucous layer in the eel, Anguilla anguilla L.

The structure of the mucous layer covering the oesophageal epithelium was analysed by scanning electron microscopy in the eel, Anguilla anguilla . Different fixation procedures were used to conserve the mucus in situ. The mucous layer changes progressively down the oesophagus from a thick dense layer to a very thin fibrous network. The possible roles of these mucous structures in ion absorption are discussed.     

Differentiation of endocrinocytes in the small-intestinal epithelium of albino rats in ontogenesis]

By means of the light microscopy method differentiation and dynamics on contents of endocrinocytes have been studied in epithelium of the initial part of the jejunum, of the caudal part of the ileum and of the middle part between them during pre- and postnatal periods of development. Formation of the endocrine apparatus of the mucous membrane epithelium in the small intestine takes place simultaneously with tissue differentiation of the epithelial layer. The population density of endotheliocytes of the mucous membrane is maximal in the initial part of the jejunum and decreases gradually in the caudal direction. By the 15th day of the postnatal development endocrinocytes in composition of the epithelium in the small intestine reach a high level of the specific differentiation and their amount increases by 1.3 times in comparison with that in newborn animals.     

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。     

Changes in the activity of alcohol dehydrogenase isoenzymes during the estrus cycle in the vagina of the rat

In rodents, the vaginal epithelium undergoes cyclical changes with an alternating pattern of keratinization and mucification. It has been known for decades that vitamin A and its active form retinoic acid are responsible for normal epithelial homeostasis. However, it has not so far been certain which enzymes catalyze the first and rate-limiting step in retinoic acid synthesis. By means of microdissection and ultrathin-layer gel electrophoresis, alcohol dehydrogenase isoenzyme activity was determined quantitatively in the various layers of the vaginal mucous membrane. It was found that, in the rat, only alcohol dehydrogenase 3 and 4 are expressed. Marked cyclical changes of alcohol dehydrogenase 4 activity in the stratum germinativum of the vaginal epithelium strongly support the assumption that this isoenzyme is responsible for retinoic acid synthesis, and that it is essential for the changes accompanying keratinization and mucification.     

香鱼消化道及肝脏的形态结构特征

采用解剖及石蜡切片显微技术观察了香鱼消化道及肝脏的组织学结构。香鱼消化道由口咽腔、食道、胃及肠构成。口咽腔大且狭长,其底壁前部有一对粘膜褶,两颌边缘着生宽扁梳状齿,腭骨及舌骨具齿,犁骨无齿;舌由基舌骨突出部分覆盖粘膜构成,舌粘膜上皮为复层扁平上皮,含有较多的杯状细胞和味蕾。食道、胃及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道粘膜层上皮为复层扁平上皮,杯状细胞发达。胃呈V形,由贲门部、胃体部及幽门部组成,胃壁粘膜上皮为单层柱状上皮,贲门部与胃体部的固有层中有胃腺。肠较短,由前、中、后肠构成,肠壁粘膜上皮为单层柱状上皮,其游离面具微绒毛;上皮细胞间有杯状细胞。幽门盲囊有350～400条,其组织学结构与肠相同。肝脏单叶,外被浆膜;肝细胞形态不规则,肝小叶界限不明显。     

Functional and morphological characteristics of the digestive reaction of gastric mucosa

Morphological state of connective tissue (stromal) cells of the stomach mucous membrane has been studied in healthy persons, having a habitual regime of feeding. During digestive period in the stomach mucous membrane, certain changes develop, which are considered as a digestive reaction. Three stages of the digestive reaction, having strict morphological signs are determined, their connections being stated by means of morphometry and mathematical analysis. I stage (preparatory) is characterized with a moderate vascular reaction, degranulation of mast cells under the superficial++ epithelium of the mucous membrane, with a moderate neutrophilic leukopedesis and a moderate lymphocytic infiltration; II stage (developed) is distinguished as a definitely demonstrated reaction of the microcirculatory bed, intensive degranulation of mast cells at all levels of the mucous membrane, massive discharge of neutrophilic granulocytes and lymphocytes into stroma; III stage (restorative) is characterized with a predominance of fibroblasts and fibrocytes, with reparation of mast cells, with decreasing saturation of stroma with neutrophilic granulocytes, lymphocytes, an increased number of eosinophilic granulocytes takes place. The data obtained widen our knowledge on functional morphology of the stomach mucous membrane, normal and at gastroduodenal pathology.     

The phenomenon of hyperproduction and in vivo shedding of excess epithelial layers of intestinal villi

The native mucosa of enterobioptates of different animal species and men was examined with the use of binocular magnifier in combination with microscopic studies of serial sections of some intestinal villi isolated from mucous membrane. Areas with masses of fully or partially rejected excessive epithelial structures (long folds, plates, tubules) were revealed. The phenomenon under study is one of the sources of the epithelium in the mucous layer on the luminal surface of the small intestine.     

Dynamics of Shigella interaction with the epithelium in the infection process

The study of the adhesion of Shigella flexneri to intestinal mucosal explants from human postabortion fetuses, used as an experimental model, has revealed that the process of interaction between the infective agent and the epithelium develops in accordance with Langmuir's equation of the adsorption isotherm. The specific biological feature of the adhesive interaction between bacteria and the mucous membrane is the fact that the effective adhesion of microbes is possible only in case of their high concentration on the surface of the mucous membrane. In case of their low concentration in the parietal layer no microbial adhesion is observed, whereas epithelial villi infected with shigellae and fixed to the mucous membrane of the explant produce a high parietal concentration of the infective agents, which leads to the increase of adhesion by more than two orders.     

小鼠胚胎发育过程中表皮生长因子受体的免疫荧光定位研究

用间接免疫荧光法研究了第12—19天小鼠胚胎的表皮生长因子受体(EGFR)在各种组织中的分布。结果表明,特异性荧光出现在EGFR阳性细胞的细胞膜上。第14.5天鼠胚鼻粘膜上皮首先显示很强的EGFR特异性荧光,此后荧光稍为减弱,直至第19天后消失。消化系统中,舌味觉上皮在第16天、胃粘膜上皮在第17—18天间、十二指肠上皮在第17.5—18.5天、直肠粘膜上皮在第15.5—16天和肛管粘膜上皮在第15天均显示强特异性荧光。肝细胞从第14.5天起有弱阳性反应,随胎龄增大强度缓慢地增强。此外,在胚胎发育不同时期,还看到若干组织呈现阳性反应,包括膀胱粘膜变移上皮、眼睑原基、腺垂体上皮、舌下腺腺泡细胞、附属腺上皮细胞、胰岛细胞、颌下腺腺上皮和导管上皮细胞、降主动脉内皮以及卵巢髓质部富含血管的疏松结缔组织中的成纤维细胞等。     

Epithelial ultrastructure and the distribution of an estradiol sensitive antigen in the vagina of adult mice

Summary The distribution of an antigenic material specific for the cervicovaginal epithelium (CVA) was studied in the vaginal epithelium of the adult mouse with immunofluorescence and immunoferritin techniques. The antigen localization has been correlated to the fine structure of the vaginal epithelium in various states of functional activity. The antigen distribution in adult ovariectomized mice and in ovariectomized mice treated with estradiol was compared with that in normal cycling mice. CVA was found to be associated with the exterior of the cell membrane of vaginal epithelium cells, being part of the glycocalyx.Two cell types, mucous or keratinized, are derived from the germinative cell layer of the vaginal epithelium, depending on the hormonal environment. Mucous cells with morphological features that characterize cells about to cornify have been demonstrated. Fluorescence as well as ferritin particles, indicating the presence of antigen-antibody complexes, were seen within the mucous droplets of the mucous cells. The CVA production is apparently connected with vaginal mucus formation. The CVA distribution in the adult vaginal epithelium is discussed in relation to the distribution demonstrated earlier in the cervicovaginal epithelium of neonatal mice.This investigation was supported by grants from the Norwegian Cancer Society (Landsforeningen mot Kreft) and the Norwegian Research Council.     

DNA content and the endometrial cellular mitotic activity in the phase of menstrual bleeding

Endometrium obtained during menses from 46 healthy women in reproductive age was investigated morphologically and cytospectrophotometrically in order to solve the problem on the source of the cells reepithelizing the uterine mucous membrane after desquamation. It was stated that desquamation takes place not in the whole functional layer of endometrium, some mucous fragments, covered with persisting luminal epithelium, are always preserved. During endometrial regeneration the cells of the luminal and glandular epithelia and those of endometrial stroma are predominantly diploid. The amount of premitotic cells in population is so small that they cannot secure any intensive cellular proliferation. Mitogenesis in endometrium is stimulated only after a complete restoration of the epithelial layer. It is suggested that persisting luminal epithelium is the source of cells for reepithelization; they migrate towards endometrial "wounds" and repair defects in the uterine mucosa during the regeneration phase.     

Structure and histochemical characteristics of the mucosa of the Vater's ampulla in man (according to materials of aimed biopsies)]

Examination of 52 aimed duodenal biopsies has revealed that there are several variants of the structure of the Vater's papilla mucous membrane. In a number of cases it is identicalto the mucous membrane of the duodenum. In 20 cases the Vater's papilla was covered with mucoid epithelium which was histochemically similar to the epithelium lining the stomach, bile ducts and the gallbladder. The "intermedial" forms found in these cases appearedto be capable to change into mucoid or edging epithelium. The mucous cells occasionally found in the Vater's papilla epithelium might be a variation of goblet cells. It seems that they are secreting by holocrine type.     

Localization of basal cell antigen in the epithelial tissues of animals and humans detected by means of natural antibodies

By means of the immunofluorescent method using rabbit serum that contains natural antibodies against the basal cell antigen of epidermis, the distribution of the antigen has been demonstrated in cells of the basal layer of all types of the stratified epithelium. The reaction is also noted in cytoplasm of the epithelial cells in the thymus and the tracheal mucous membrane. This demonstrates their histogenic affinity to stratified epithelii. The antigen studied is not species-specific, since it is revealed in the stratified epithelium of all species examined (human being, mouse, rat, guinea pig, rabbit). It is possible to use the basal cell antigen as a marker for immunomorphological reveal of epithelial cells in the thymus in the process of its physiological and pathological involution.     

The oesophagus and stomach of dolphins (Tursiops, Delphinus, Stenella)

The morphology of the oesophagus and stomach has been studied in several species of Tursiops, Delphinus and Stenella and correlated with the histological and ultrastructural characteristics of each region. The oesophagus opens into a saccular forestomach, lined by stratified squamous epithelium. A narrow opening leads into a globular main stomach with a plicated glandular mucous membrane possessing mucous, parietal and chief cells. The main stomach communicates with pyloric stomach by a narrow connecting channel possessing sphincteric constrictions. Variations in the connecting channel have been found in the species examined. The mucosae of the channel and the pyloric stomach are similar and contain typical pyloric glands. Argentaffin cells are present. The cytological and other characteristics of the component chambers have been interpreted in relation to feeding habits and digestion in dolphins.     

The anatomy and topography of the lymphoid formations of the human stomach in postnatal ontogeny]

By means of macro-microscopical methods 80 stomachs from persons of various age have been studied. In the mucous membrane of the human stomach during all age periods of postnatal development the lymphoid tissue is present as diffusely scattered lymphocytes, their microaccumulations and lymphoid noduli. Maximal amount of the lymphoid noduli is observed during the second mature age. The greatest number of the lymphoid noduli per 1 cm2 of the mucous membrane surface is revealed in the area of the lesser curvature and in the pyloric part of the stomach. Most often the lymphoid noduli are situated in the depth of the lumen proper of the mucous membrane, somewhat more seldom--in its more superficial parts, in the muscular lamina and in the submucous tela. The lymphoid noduli with germinative centers are met beginning from the first childhood up to old age. The greatest amount of diffusively scattered lymphocytes is situated near the lymphoid noduli and in the deep layer of the lamina proper of the mucous membrane.     

Immunohistochemical Localization of Six Galectin Subtypes in the Mouse Digestive Tract

Galectin, an animal lectin that recognizes β-galactoside of glycoconjugates, is abundant in the gut. This IHC study showed the subtype-specific localization of galectin in the mouse digestive tract. Mucosal epithelium showed region/cell-specific localization of each galectin subtype. Gastric mucous cells exhibited intense immunoreactions for galectin-2 and galectin-4/6 with a limited localization of galectin-3 at the surface of the gastric mucosa. Electron microscopically, galectin-3 immunoreactivity coated indigenous bacteria on the gastric surface mucous cells. Epithelial cells in the small intestine showed characteristic localizations of galectin-2 and galectin-4/6 in the cytoplasm of goblet cells and the baso-lateral membrane of enterocytes in association with maturation, respectively. Galectin-3 expressed only at the villus tips was concentrated at the myosin-rich terminal web of fully matured enterocytes. Epithelial cells of the large intestine contained intense immunoreactions for galectin-3 and galectin-4/6 but not for galectin-2. The stratified squamous epithelium of the forestomach was immunoreactive for galectin-3 and galectin-7, but the basal layer lacked galectin-3 immunoreactivity. Outside the epithelium, only galectin-1 was localized in the connective tissue, smooth muscles, and neuronal cell bodies. The subtype-specific localization of galectin suggests its important roles in host-pathogen interaction and epithelial homeostasis such as membrane polarization and trafficking in the gut. (J Histochem Cytochem 57:41–50, 2009)     

Topo-optical study of the pulmonary ciliary membrane surface.

In hydrophilic media of high refraction index the cilia of the epithelium of the tracheo-bronchial mucous membrane and the mucous film demonstrate birefringence positive to the longitudinal axis of the mucous membrane owing to the identical orientation the glycoprotein macromolecules and of the fatty acid chains of the ciliary membrane. By means of toluidine blue staining the mucous film and the ciliary zone can be studied selectively by polarization microscopy. The opposite optical character suggests that the dye molecules are perpendicularly connected to the long glycoprotein chains of the mucous, and there is an oriented connection perpendicular to the longitudinal axis of the cilium in its lipid membrane. In smears of bronchial secretion or mucous membrane scrapings after staining, with toluidine blue pH 7.0, the selective optical reaction of the cilia provides a possibility for the study of isolated desquamated ciliary cells. The reaction is given by the lipid membrane boundary of the cilia. In embedded, lipid-extracted sections, the cilia and the mucous film show a minimum of birefringence in the unstained state. After toluidine blue staining or aldehyde-bisulphite-toluidine blue (ABT) reaction the mucoid surface and the ciliary zone display an opposite optical reaction originating from the dehydrated mucoproteins adsorbed onto the surface of lipid-extracted cilia.     

Cytodifferentiation of the epithelium of the gastric mucosa glands of rats in ontogenesis

Structure of epithelium in the mucous membrane glands of the rat stomach has been studied electron microscopically during embryonal and postnatal periods of development. Time of initial appearance of various types of cells in early stages of the gastric epithelium histogenesis has been verified. Asynchronity of their appearance is demonstrated. In epithelium of the gastric glands in 20-day-old rat embryos poorly differentiated exocrine and also endocrine D- and G-cells are revealed. On the 1st day EC-, ECl-, and on the 3d day--X-endocrinocytes appear. Neighbouring exocrinocytes connect with each other by means of both nonspecific and specific intercellular contacts. Exocrine and endocrine cells connect by means of desmosomes. For the animals of each age group certain range of ultrastructural organization in variously differentiated glandulocytes (they are morphological basis of the reactive changes) is specific.