Anatomo-radiologic study of the mesenteric small intestine using double-contrast enema. II. The surface of the mucous membrane

X-ray analysis were used to study the jejunum and ileum, in vivo. 2019 patients were examined by double contrast small bowel enema. We considered some parameters concerning the folds of its mucous membrane and its thickness and depth. Furthermore, we considered the radiological appearance of the Peyer's patches and solitary lymphatic follicles. The results are according to the literature.     

The energetics of coprophagy: a theoretical analysis

Lagomorphs, many rodents and some other small mammals eat their faeces during the part of the day when they are not foraging for fresh food. One of the possible benefits of this habit of coprophagy is that it may enable them to extract more energy from their food. A computer model is used to assess the likely benefits and explore their relationships to food, feeding rate and gut morphology. The predicted benefits are much larger for hindgut fermenters than for foregut fermenters, and especially large for hindgut fermenters with relatively small fermentation chambers. They are larger for poor foods (with lower proportions of cell contents) than for richer ones. At low feeding rates the energetic advantage of coprophagy may disappear if the faeces from food eaten during one feeding period emerge largely during the next, but this can be avoided by adjusting the rate of passage of gut contents during the intervening rest period.     

Permeability of cyanobacterial mucous surface structures for macromolecules

The space of diffusive distribution of neutral hydrophilic macromolecules (dextrans with molecular sizes of 1.5 to 9 nm in the Stokes’ radius values) in the mucous surface structures (MSS) of intact bacterial cells has been studied for the first time on cyanobacteria. Cyanobacterial species and strains under study belong to different taxonomic groups, the members of which form MSS of various morphology and ultrastructure and can grow in association with plants and animals, inter alia as mucous microcolonies. The range of permeability has been determined by the fractionation of polydisperse dextrans method, previously applied for plants, in combination with electron microscopy. Dextrans are supposedly distributed in the MSS polysaccharide matrix in accordance with their sizes, in much the same way as in a macroporous unitary gel. The similarity of the chemical composition and macromolecular organization of cyanobacterial MSS with pectins of plant cell walls and the role of MSS and the intercellular matrix as permeability barriers in associative interactions of microorganisms are under consideration.     

Permeability of cyanobacterial mucous surface structures for macromolecules

The space of diffusive distribution of neutral hydrophilic macromolecules (dextrans with molecular sizes of 1.5 to 9 nm in the Stokes radius values) in the mucous surface structures (MSS) of intact bacterial cells has been studied for the first time on cyanobacteria. Cyanobacterial species and strains under study belong to different taxonomic groups, the members of which form MSS of various morphology and ultrastructure and can grow in association with plants and animals, inter alia as mucous microcolonies. The range of permeability has been determined by the fractionation of polydisperse dextrans method, previously applied for plants, in combination with electron microscopy. Dextrans are supposedly distributed in the MSS polysaccharide matrix in accordance with their sizes, in much the same way as in a macroporous unitary gel. The similarity of the chemical composition and macromolecular organization of cyanobacterial MSS with pectins of plant cell walls and the role of MSS and the intercellular matrix as permeability barriers in associative interactions of microorganisms are under consideration.     

Morphological features of mucous secretory organ and mucous secretion of loach Misgurnus anguillicaudatus skin for friction drag reduction

We examined the functional morphology of loach Misgurnus anguillicaudatus skin by using synchrotron X-ray micro-computed tomography (SR-μCT) and high-contrast staining using osmium tetroxide or phosphotungstic acid (PTA), which enhances the image contrast of soft tissues. The captured high-spatial resolution images revealed that the surface ornamentations were stuck in the basement membrane of the loach scales. The ornamentations consisting of grooves (radii) and ridges (circuli) that can move freely and bend flexibly. The cross-sectional lateral microstructures of flat, concave and convex loach skins were observed from a live image of loach skin obtained through dark-field optical coherence tomography (OCT) imaging. The thickness of loach skin was changed with varying empty space between the mucous-cell layer and the scales by bending motion of loach. In addition, through direct measurement of drag reduction of loach skin, the mucous layer was found to have a strong influence on the reduction of skin friction. The present results enhance the understanding of the functional morphologies of mucous layer of loach to secrete mucus for skin friction reduction.     

The skin of birds' feet: Morphological adaptations of the plantar surface

The skin of the foot provides the interface between the bird and the substrate. The foot morphology involves the bone shape and the integument that is in contact with the substrate. The podotheca is a layer of keratinized epidermis forming scales that extends from the tarsometatarsus to the toe extremities. It varies in size, shape, amount of overlap and interacts with the degree of fusion of the toes (syndactyly). A study of toe shape and the podotheca provides insights on the adaptations of perching birds. Our analysis is based on micro‐CT scans and scanning electron microscopy images of 21 species from 17 families, and includes examples with different orientations of the toes: zygodactyl (toes II and III forward), anisodactyl (toes II, III, and IV forward), and heterodactyl (toes III and IV forward). We show that in these three groups, the skin forms part of a perching adaptation that involves syndactyly to different degrees. However, syndactyly does not occur in Psittacidae that use their toes also for food manipulation. The syndactyly increases the sole surface and may reinforce adherence with the substrate. Scale shape and toe orientation are involved in functional adaptations to perch. Thus, both bone and skin features combine to form a pincer‐like foot.     

Intestinal peptidase content of the mucous coat of the small intestine in dogs

The content of leucine aminopeptidase, cathepsins B and D was measured in the mucous coating of the small intestine and duodenal juice of adult fistula dogs. It was shown that inhibitory assay was mandatory for measuring the content of intestinal peptidases. The authors discuss the possibility of hydrolysis of food substrates in the parietal layer of the mucous coating by proteolytic enzymes of both intestinal and pancreatic origin.     

超微七味白术散对菌群失调腹泻小鼠小肠黏膜的影响

目的 探讨超微七味白术散对抗生素相关菌群失调腹泻的疗效机制.方法 采用灌胃头孢拉啶和硫酸庆大霉素混合抗生素进行造模,然后分别灌胃七味白术散的传统汤药全量和超微汤药1/2剂量进行治疗,正常组和模型组分别灌胃等量的无菌水.结果 抗生素造模后,小鼠体重的变化量和变化率都较正常组小,差异无统计学意义(P＞0.05),小鼠的小肠黏膜组织发生绒毛脱落、炎症细胞浸润、固有膜毛细血管扩张等病理变化;传统汤药治疗组和1/2剂量超微汤药治疗组小鼠体重的变化量和变化率都比正常组、模型组大,且1/2剂量超微汤药组的与正常组的差异有统计学意义(P＜0.05),该两组小鼠的肠道组织病理情况有所改善,1/2剂量超微汤药治疗组小鼠的肠道组织恢复情况最好,传统汤药治疗组次之,模型组也稍有改善.结论 1/2剂量超微七味白术散对恢复菌群失调腹泻小鼠的小肠黏膜的结构具有较好的修复作用,对小肠吸收功能具有促进作用.     

Morphological and histochemical analysis of mucous membrane transformation of the artificial urinary bladder

The performed morphological study of the transformation mechanism of the intestinal reservoir of the mucous membrane using modern immunochemical and histochemical methods revealed three morphological phases of enteric epithelium adaptation: reactive-inflammatory, compensatory-protective, and atrophic. The enteric urinary reservoir preserves a cambial apparatus typical of the enteric phenotype with inherent apoptosis activity and proliferation, which confirms the low level of the tumor transformation risk.     

Modifications to the surface of T-lymphocytes in chronic candidiasis of the skin and mucous membranes

27 patients with chronic candidiasis of the skin and mucous membranes have been examined with a view to study the expression of E-receptors and its changes after the incubation of T-lymphocytes with theophylline, levamisole, thymaline and Candida albicans antigen. This study has revealed that, in comparison with healthy persons, most patients show decreased expression of E-receptors, and the character of their changes after incubation with the above-mentioned preparations is essentially different. The deviations revealed in this study have been regarded as the modification of T-cell membranes, which is seemingly one of the reasons of the weak competence of T-cells. In its turn, the expression of E-receptors may be considered as an indicator of the influence of different factors on T-lymphocytes. Substances altering the level of cyclic nucleotides in the cell, the antigenic fractions of the fungal causative agent, the suppression or blocking the action of thymic hormone-like substances may serve as such factors.     

A simple method for prevention of coprophagy in the mouse

A series of studies of coprophagy in mice has been conducted from the viewpoints of behaviour and nutrition. Since it was necessary to prevent coprophagy to investigate its significance, an attempt was made to devise a restrainer. A polyethylene bottle was cut and fixed to the mouse so as to prevent its head from reaching its anus when faeces were excreted. The animals were also housed in cages with floors of larger mesh size in order to let the faeces fall through.     

The role of coprophagy in the feeding strategies of terrestrial isopods

Summary The hypothesis that faeces recycling in isopods evolved as an adaption to facilitate maintenance of an adequate copper balance in terrestrial environments is examined. Experimental observations on the consumption, absorption and growth rates of Porcellio scaber fed Betula pendula leaf litter varying in copper content and extent of microbial decay are reported. Preventing the isopods from reingesting their faeces caused a reduction in the growth rates of experimental animals fed their natural low copper diet but also of those fed copper enriched diets. When the availability of copper in the primary food was increased consumption of the litter decreased and growth rates were significantly reduced. These results suggest that copper is not normally a critically limiting nutrient for terrestrial isopods.When the primary diet was supplemented with shredded carrot, faeces deprivation did not cause a decrease in growth rates. These experimental animals gained weight significantly faster than controls fed decaying leaf litter alone.Faeces formed a significantly greater proportion of the diet when the animals were fed freshly fallen rather than decayed litter.We conclude a) that enhanced microbial activity in the faeces increases their nutrient status in such a way that some coprophagy is necessary in order to optimize overall nutrient uptake, and b) that theability to vary the extent to which faeces are recycled in response to differences in food quality is important in that it introduces greater flexibility into the feeding strategies of these generalist macro-decomposers.     

Site differences of Toll-like receptor expression in the mucous epithelium of rat small intestine

Toll-like receptors (TLRs) are known to recognize pathogen-associated molecular patterns and might function as receptors to detect microbes. In this study, the distribution of TLR-2, -4 and -9 were immunohistochemically investigated in the rat small intestine. As a result, TLR-2 was detected in the striated borders of villous columnar epithelial cells throughout the small intestine, except for the apices of a small number of intestinal villi. TLR-4 and -9 were detected in the striated borders of the villous columnar epithelial cells only in the duodenum. TLR-4-immunopositive minute granules were found in the apical cytoplasms of epithelial cells, subepithelial spaces and blood capillary lumina. TLR-2 and -4 were detected in the striated borders of undifferentiated epithelial cells and in the luminal substances of the intestinal crypts throughout the small intestine, but TLR-9 was not detected in the crypts throughout the small intestine. Only TLR-4 was detected in the secretory granules of Paneth cells in both the jejunal and ileal intestinal crypts. These findings suggest that duodenal TLRs might monitor indigenous bacteria proliferation in the upper alimentary tract, that TLR-2 might also monitor the proliferation of colonized indigenous bacteria throughout the small intestine, that the lack of TLR-2 at the villous apices might contribute to the settlement of indigenous bacteria, and that TLR-2 and -4 are secreted from intestinal crypts.     

Structure of the mucous membrane of the distal part of the large intestine in the monkey

By means of histological, histochemical, immunohistochemical and morphometrical methods, according to 24 objective morphological parameters, bioptates of endoscopically unchanged mucosal membrane of the large intestine, obtained from 22 clinically healthy macaque rhesus males, have been studied. The data on vital structure and cellular interconnections in the mucous membrane of the distal part of the large intestine have been received. The data can be used for estimating certain pathological processes, when modelling the large intestine diseases in monkeys.     

Glycoprotein transport in the surface mucous cells of the rat stomach

The intracellular transport of glycoproteins pulse-labeled in vitro with tritiated leucine and galactose in the surface mucous lining cells (SMC) of the fundus of the rat stomach was studied by electron microscope autoradiography. The SMC survive for several hours in pieces of the fundus incubated in a bicarbonate-buffered medium. The SMC have a normal ultrastructure for at least 4 h of incubation. Kinetic activity is normal for at least 5 h, as demonstrated by the normal nuclear incorporation of tritiated thymidine; The SMC incorporate labeled leucine and galactose at normal rates up to 4 h and 6 h, respectively. In contrast to the SMC, the cells of the gastric glands show signs of degeneration within 1 h after the start of incubation. In the SMC the secretory protein forms a smaller part of the total protein synthesized than in other secretory cells studied. The intracellular tranpsort of the leucine-labeled moiety of the glycoproteins follows the normal pathway. The RER loses 35% of its transportable labeled protein within 30 min. The Golgi complex is maximally labeled at 40 min and the mucous granules after 120 min. Galactose is attached to the glycoproteins mainly in the Golgi complex. Glycoproteins are not secreted within 2 h after synthesis of their protein moiety.