[Morphological characteristics of glands of the ileocecal angle sphincter region in adults]. / Morfologicheskaia kharakteristika zhelez v oblasti sfinkterov podvzdoshno-slepokishechnogo ugla u vzroslogo cheloveka.

Structural feature of the large intestine glands (Liberkun crypts), located in the thickness of the ileocoecal angle valve and in the zone of appendix valve were studied using macro-microscopic methods. The material was obtained from cadaveres of 28 men and women who died at the age of 60-67. The causes of their deaths were not associated with digestive or immune system pathology. Morphometric investigations performed revealed that the density of the glands arrangement in these sphincter zones of the large intestine ileocecal angle, the area occupied by them and their length both on cross and longitudinal sections exceeded the same parameters in the zone of the coecum cone in all the observations.

The "human"-like morphology of the swine papilla ilealis.

The morphology of the ileocecocolic transition, between the small and large intestine was studied in 33 male, adult pigs of unknown breed. The results were analyzed by the Wilcoxon Test (alpha < or = 0.05). The ileum opened into the large intestine, in all of the cases, at the level of the cecocolic junction in the form of a conical papilla (ileal papilla) turned towards the large intestine, with an oblique caudal and lateral direction, pointing to the cecal lumen. The cranial contour is higher than the caudal one, with average values of 3.0 cm, and 1.5 cm in the fresh specimens and 2.8 cm and 1.4 cm after fixation of the specimens. The average diameter of the papilla apex was 1.5 cm, both in the fresh specimens and in the fixed ones. In 100% of the cases the ileal papilla appeared with a star-shaped orifice in its apex in both the fresh and in the fixed specimens. Our studies showed that the transition between the small and large intestine of the swine is ileocecocolic, thus similar to humans and different from the ileocecal (Perissodactyla, Rodentia, Lagomorpha) and, according to most descriptions, ileocolic (dog) transitions found in other animals.

Arrangement of the tunica muscularis of the ileum, cecum and colon at the transition between the small and the large intestines of swine.

The arrangement of the bundles of muscular fibers in the transition between the small and the large intestines was studied in 12 male adult crossbred swine by dissection, after immersion in 50% nitric acid solution. The connection between the small and the large intestines was formed by the association of the muscular tissue, the connective tissue and the fat tissue. The tunica muscularis of these organs was organized in thin thread-like bundles and wide ribbon-like bundles of variable width and thickness. The superficial bundles of the longitudinal stratum of the tunica muscularis of the ileum established the continuity with the large intestine; the deep bundles penetrated into the ileal papilla. The limit between the cecum and the ascending colon was externally marked by the sulcus cecocolicus dorsalis and ventralis. The connection between the cecum and the ascending colon was formed by bundles of muscular fibers coming from the ileum, and the taeniae ventralis, lateralis and medialis of the cecum. Some bundles of muscular fibers from the ascending colon and the cecum headed toward the sulcus cecocolicus. The median bundles of muscular fibers of the taenia ventralis of the cecum, near the termination of the ileum, were arranged to form a loop around the termination of the ileum, mixing with the musculature of the ascending colon at the level of this junction.

Distribution of mast cells in human ileocecal region.

The number and histochemistry of mast cells were analyzed in surgical specimens of the ileocecal junction and neighboring intestinal segments. All the basophilic cells contained tryptase and some were immunoreactive for chymase, vasoactive intestinal polypeptide, or nitric oxide synthase. The medium density of mast cells per square millimeter was 31.90, 110.38, 72.83, 29.80, and 32.70, in the mucosa, submucosa, inner circular, outer circular, and longitudinal muscle layers, respectively. Mast cell density was higher at the ileocecal junction (for all layers together, 79.29 mast cells/mm2) than elsewhere (mast cells/mm2: ileum, 52.29; cecum, 59.22; cecocolonic junction, 54.65; ascending colon, 48.63). The differences among layers and among segments were significant and might be due to layer- and region-specific mast cell roles. Mast cell richness in the muscle coat, especially in the inner circular muscle layer, might be important in regulating its motility.

Absence of secretory component expression by epithelial cells overlying rabbit gut-associated lymphoid tissue.

The expression of secretory component by epithelial cells overlying intestinal lymphoid aggregates was examined immunocytochemically in rabbits. Intensely labeled epithelial cells were distributed along surfaces of villi surrounding follicles in jejunal and ileal Peyer's patches and along interdomal epithelium in sacculus rotundus and appendix. Secretory component labeling extended from within crypts and appendiceal crevices to the tips of villi and interdomal regions. In contrast, no immunologically detectable secretory component sites were observed in follicle-associated epithelial cells. In crypts and crevices supplying follicles, epithelial cells facing the lamina propria of villi and interdomal epithelium expressed secretory component, but cells flanking the follicle domes lacked secretory component immunostaining, with a clear demarcation between positive and negative zones at the base of the stem cell regions. These findings demonstrate a unique difference in the expression of the receptor for immunoglobulin A antibody between follicle-associated and non-follicle-associated epithelium.

Effect of chronic ethanol ingestion on enterocyte turnover in rat small intestine.

Whether chronic ethanol ingestion significantly damages the small intestine remains controversial. To clarify this we have analysed the morphology of the small intestinal epithelium and quantified its renewal in chronically ethanol fed rats. Twenty adult male rats were pair fed for 28 days a nutritionally adequate liquid diet containing either ethanol as 36% of total calories or an isocaloric diet in which fat substituted for ethanol. Crypt cell production rate was determined in the jejunum and ileum by the metaphase arrest method. Weight gain and small intestinal morphology were similar in ethanol fed and control rats, but enterocyte turnover was significantly reduced in the jejunum (p less than 0.05) and ileum (p less than 0.01) of the ethanol fed rats. This effect of ethanol on the small intestine is probably systemic rather than local, because the changes in jejunum and ileum were similar, and it may contribute to the development of malnutrition in chronic alcoholics.