Intraorganic blood vessels of the intestinal graft after its ortho- and heterotopic transplantation

In experiments, performed on 85 dogs of both sex ortho- and heterotopic total autotransplantation of the small intestine and extracorporal connection of the allogenic segments of the small intestine have been carried out. Certain dependency of morphological changes of the intraorganic blood bed on the operation model has been stated. Essential changes in the blood bed at the heterotopic autotransplantation depend on inadequate regional hemodynamics in the graft. Therefore, the heterotopic model should be considered less preferable than the orthotopic one. One of the peculiarities in reconstruction of the intraorganic vascular bed after ortho- and heterotropic transplantation of the small intestine is, evidently, opening of lympho-venular anastomoses.     

Structural changes in the small intestine wall and its lymphatic bed after gastrectomy

Morphologically and histochemically structural changes of the small intestine wall and its lymphatic bed have been studied in 104 dogs after the stomach resection. After the operation an increase in the diameter of the lymphatic capillaries and vessels takes place. Lateral dilatations and protrusions in the capillary walls appear, new anastomoses in all the membranes are formed, they are mostly manifested in the mucous membrane. Histopathological rearrangement in the small intestine wall is demonstrated as edema of the mucous membrane, as plethora of the vessels, as lymphoid infiltration and as changes of the villi forms.     

ultrastructure of rosette-forming cells in the wall of intestinal allotransplant]

The development of a specific rosette-formation was observed following total allotransplantation in the small intestine wall. The rosettes were formed from the central lymphocyte or neutrophil and adjucent plasmatic cells. The formation of plasmatic rosettes (P-rosettes) is considered as a possible index of the graft reaction versus the host.     

Immune response of CBA mice in postnatal ontogeny

Changes in the pattern of immune response of the CBA mice during postnatal ontogenesis were studied on the models of cellular and humoral immunity. The functions mediated by the amplifier cells were shown to undergo the most significant changes. This was confirmed by a decrease in the activity of antigen-nonspecific T-suppressors, as estimated in a semisyngeneic system, an increase in the capacity of spleen lymphoid cells to induce the "graft versus host" reaction with the age and preservation of the function of hypersensitivity effectors of delayed type at the same level (after the age of 3-4 months). It is suggested that these changes might cause an age decrease in the suppressor activity of T-cells in a response to insoluble antigens.     

Developmental changes in the inner surface structure of the bovine large intestine

The developmental pattern of the bovine fetal large intestine was studied with particular reference to the appearance and decline of the intestinal villi during the fetal period. In the bovine large intestine, the first rudimentary villus and goblet cells were seen in the rectum in a fetus estimated to be 3 months old. By 5-6 months, the goblet cells, absorptive cells in the intestinal crypts, and vacuolated cells in the villi were present along all segments of the large intestine. By 8-9 months, the villi have disappeared from the colon and rectum, epithelial cells no longer contain vacuoles, and absorptive and goblet cell populations are emerging from the crypts. These histological results suggest that development in the bovine large intestine follows a recto-cecal gradient and the most distinct turning point during the fetal period is the first disappearance of fetal villi in the rectum of fetuses estimated to be 7 months old. After this stage, the mucous membrane of the colon and rectum matured rapidly before birth. In contrast, the cecum may seem to require further development in perinatal life.     

Concomitant changes in adenylate cyclase and cytolytic activities of lymphoid cells during graft versus host reaction.

Spleen cells from adult F1 hybrid mice undergoing the graft versus host reaction due to the inoculation of lymphoid cells of parental origin showed increased adenylate cyclase activity and cytolytic activity. A time-course study revealed that both the adenylate cyclase and cytolytic activities started increasing at Day 4 and reached maximum at Day 8 of initiation of the graft versus host reaction. Furthermore, the magnitude of both adenylate cyclase activation and cytolytic activity were dependent upon the number of parental cells injected into the F1 hybrid recipients. Elevated adenylate cyclase activity was also observed in spleen cells from irradiated animals undergoing the graft versus host reaction in which the nonspecific, but not the specific cytolytic activity was markedly depressed.     

Immunocytochemical localization of prostaglandin endoperoxide synthase in the bovine intestine

The localization of prostaglandin (PG) endoperoxide synthase in bovine intestine was examined immunocytochemically with polyclonal antibody raised against PG endoperoxide synthase purified from bovine seminal glands. The most intense positive staining reaction for the enzyme was present in mast cells. Mast cells were found to be widely distributed in the intestinal wall, and were particularly numerous in the lamina propria. Most of the mast cells in the lamina propria of the intestinal villi were elongated and oriented with their long axis parallel to the plane of the absorptive epithelium. In whole mount preparations of jejunal villi, mast cells were seen to form a two-dimensional network in the lamina propria. In addition to mast cells, smooth muscle cells of the inner circular muscle layer and muscularis mucosae, nerve cells and fibers, endothelial cells of arterioles, and serosal epithelial cells also showed faint to moderate staining for the enzyme. These results suggested that mast cells are the major source of PGs in the bovine intestinal wall. The characteristic arrangement of mast cells in the intestinal villi may be related to their functions in this portion of the bovine intestine.     

Chronological observation of intestinal lesions of rats experimentally infected with Echinostoma hortense

Intestinal histopathological changes due to infection with Echinostoma hortense (Trematoda) were studied in rats after experimental infection with the metacercariae. The metacercariae were obtained from the tadpoles of Rana nigromaculata, a second intermediate host infected in the laboratory. Total 18 albino rats (Sprague-Dawley) were given 200 matacercariae each and sacrificed on the day 1, 3, 7, 11, 22 or 44 post-infection (PI). Segments of the small intestine at 1, 3, 5, 8 and 30 cm posterior to the pylorus (PTP) were resected and studied histopathologically. 1. The flukes were seen to have intruded into the intervillous space in the upper small intestine at early stages (1-3 days PI), however, they were located mainly in the intestinal lumen at later stages (7-44 days PI). The flukes were sucking and destroying the epithelial layers of villi with their oral and ventral suckers. 2. Histopathological changes of the intestine were recognizable in as early as 1-3 days after infection, and the changes became severer as the infection progressed. 3. The intestinal mucosa was histopathologically characterized by villous atrophy and crypt hyperplasia throughout the infection period. Major villous changes were blunting, fusion, severe destruction and loss of epithelial layers of villi. Villous/crypt (V/C) height ratio was remarkably reduced from 3:1 in controls to 1:1 in severely infected animals. In the stroma of villi, inflammatory cell infiltrations, vascular congestion, edema, and/or fibrosis were recognized. The goblet cells were increased in number after 11 days PI.(ABSTRACT TRUNCATED AT 250 WORDS)     

Historical review and present status of free fat graft autotransplantation in plastic and reconstructive surgery

Free fat graft autotransplantation for soft-tissue replacement has been a neglected subject in recent years. In a review of the literature, investigations of the various uses of free fat autotransplantation in animals and humans provide an understanding of the problems associated with the use of fat as a free graft. Results of free fat autotransplantation were found to be quite unpredictable, with wide variations in the resulting bulk of the graft. Microscopic studies of this behavior led to controversy as to whether the graft ultimately was made of surviving graft adipocytes (cell survival theory) or host adipocytes (host replacement theory). Studies revealed a "fibroblast-like" mesenchymal cell within adipose tissue that was believed to be an immature adipocyte precursor or preadipocyte. Further characterization of the preadipocyte and its complete differentiation was accomplished using tissue-culture techniques. These investigations provide evidence of the dynamic nature of adipose tissue that strongly supports the cell survival theory and gives explanation to the unpredictable behavior of free fat autografts. Many conditions treated by plastic surgeons require soft-tissue augmentation. Autogenous adipose tissue is the most appropriate and natural replacement material. With new culturing techniques, preadipocytes in a single cell suspension may provide an injectable soft-tissue replacement. This subject appears ripe for investigation.     

Small intestinal morphometric and biomechanical changes during physiological growth in rats

Changes in small intestinal geometry, residual strain and stress-strain properties during physiological growth were studied in rats ranging from 1 to 32 weeks of age. Small intestinal mass and dimensions increased many-fold with age, e.g. the weight per unit length increased five-fold with age and the wall cross-sectional area increased four-fold. The opening angle of duodenum obtained at zero-stress state was approximately 220 degrees and 290 degrees during the first and second week after birth and decreased to 170 degrees at other ages (p < 0.005). The opening angle of ileum ranged between 120 degrees and 150 degrees . The residual strain of duodenum at the mucosal surface did not vary with age (p > 0.05) whereas the residual strain of ileum at the mucosal surface decreased with age (p < 0.001). The circumferential and longitudinal stress-strain curves fitted well to a mono-exponential function. At a given circumferential stress, the corresponding strain values increased during the first 8 weeks of age (p < 0.05) where after no further change was observed. Hence, the small intestine became more compliant during early life. At a given longitudinal stress, the corresponding strains of ileum and duodenum became larger during the first 2-4 weeks of age (p < 0.05) where after no further change was observed. The small intestine was stiffer in longitudinal direction compared to the circumferential direction. In conclusion, pronounced morphometric and biomechanical changes were observed in the rat small intestine during physiological growth. Such data may prove useful in the understanding of the functional changes of the digestive tract during early life.     

The immunocorrective effect of laser reflexotherapy in experimental influenza infection

The influence of two schemes of laser acupuncture on some cell-mediated and humoral immunity characteristics of mice, as well as on their nonspecific antiviral resistance, in acute experimental influenza infection has been studied. The use of both schemes has been found to considerably decrease the severity of infection, enhancing the activity of lymphocytes of infected mice in the graft versus host reaction, the O2-producing activity of alveolar macrophages and modulating the ratio of antihemagglutinins and nonspecific antiviral inhibitors in the blood serum.     

The villi contribute to the mechanics in the guinea pig small intestine

Previous studies have shown that intestinal mucosa is compressed in vivo. The present study investigated the contribution of the mucosal villi to the biomechanical properties in circumferential direction in the guinea pig jejunum. Eight 20-cm-long jejunal segments were excised and each separated into two 10-cm-long segments. The mucosal villi were scraped off from half the segments. The segments were pressurized in vitro with Krebs solution from 0-10cmH(2)O using a ramp distension protocol with simultaneous diameter recordings. Circumferential stresses and strains were computed from the diameter, pressure and the zero-stress state data. Removing the villi resulted in small opening angles (139+/-16 degrees vs 189+/-27 degrees with villi) and small absolute values of residual strain (inner: -0.05+/-0.03 vs -0.33+/-0.06 with villi; outer: 0.11+/-0.04 vs 0.33+/-0.08 with villi) (P<0.001). The outer diameter as a function of the pressure did not differ between jejunal segments with villi and without villi. The average mid-wall stress-strain curve without villi was shifted to the left compared to the segment with villi, indicating the wall was stiffer without villi. However, if the stress-strain computation for the segments with villi was referenced to the zero-stress state of the segments without villi, the curve was only partly shifted to the left. In conclusion, this paper provides the first direct experimental evidence that the villi are important for the biomechanical properties of guinea pig small intestine in circumferential direction, because the villi not only affect the zero-stress state configuration but also partially affect the stress-strain distribution in the intestinal wall. Therefore, the villi should be taken into account in the analysis of biomechanical properties of the intestinal wall.     

Reactivation of allergic encephalomyelitis by means of allogeneic confrontation

Lewis rats recovered from experimental allergic encephalomyelitis (EAE) are resistant to active reinduction of disease. (DA X Lewis)F1 hybrids behave in an identical fashion. The induction of a graft versus host (GVH) reaction in EAE convalescent (DA X Lewis)F1 rats, by injection of normal parental (Lewis) lymphocytes, precipitates a second episode of EAE in a proportion of rats. This secondary episode of EAE can be induced by injection of parental cells either systemically (intravenously) or locally (subcutaneously in the foot). A host versus graft (HVG) reaction does not reactivate EAE in the convalescent host. The observed effect is probably due to reactivation of EAE effector cells following the extensive nonspecific proliferation of host lymphoid cells which is a feature of GVH reactivity.     

The distribution of cells killed by Trichinella spiralis in the mucosal epithelium of two strains of mice

Dead and dying cells were localized by light microscopy in the mucosal epithelium of the intestine of an outbred strain (CD1) and an inbred strain (B10A) of mice by vital staining with the dye, trypan blue. In whole mounts of the intestinal wall, trails, or variable-sized clusters of blue-stained cells were seen throughout the course of infection and in mice given a range of inoculum levels. In CD1 mice, irregular trails of dead cells were seen in the intestine floor and clusters of them along the villi. In B10A mice, dead cells were seen only as trails or clusters in the intestinal floor. The results suggest that worms move through the epithelium only in the intestinal floor. Cells killed by this activity may be sloughed from the epithelium more rapidly by B10A mice than by CD1 mice where the dead cells migrate up villi before being sloughed.     

酶解乳蛋白对初生仔猪小肠组织学结构及隐窝细胞增殖的影响(英文)

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The functional morphology of the scolex of Diphyllobothrium Cobbold (Cestoda, Pseudophyllidea). A scanning electron and light microscopical study on scoleces of adult D. dendriticum (Nitzsch), D. latum (L). and D. ditremum (Creplin).

Scoleces of adult D. dendriticum, D. latum and D. ditremum were studied using scanning electron and light microscopy. In D. dendriticum and D. latum the transverse bar between the bothria at the scolex apex always possessed a frontal pit while in D. ditremum no such invagination was seen. The scoleces attach to the host intestine by taking a firm grip with each bothrium around one or two intestinal villi. In D. ditremum and D. latum a layer of secreted substance is present between the scolex apex and the host intestine and between the inner bothrium surface and the host intestinal villi. In D. dendriticum, however, such a secreted layer was only observed at the scolex apex. A general account of the musculature and nervous and excretory systems of a Diphyllobothrium scolex is given.     

Postprandial morphological response of the intestinal epithelium of the Burmese python (Python molurus)

The postprandial morphological changes of the intestinal epithelium of Burmese pythons were examined using fasting pythons and at eight time points after feeding. In fasting pythons, tightly packed enterocytes possess very short microvilli and are arranged in a pseudostratified fashion. Enterocyte width increases by 23% within 24 h postfeeding, inducing significant increases in villus length and intestinal mass. By 6 days postfeeding, enterocyte volume had peaked, following as much as an 80% increase. Contributing to enterocyte hypertrophy is the cellular accumulation of lipid droplets at the tips and edges of the villi of the proximal and middle small intestine, but which were absent in the distal small intestine. At 3 days postfeeding, conventional and environmental scanning electron microscopy revealed cracks and lipid extrusion along the narrow edges of the villi and at the villus tips. Transmission electron microscopy demonstrated the rapid postprandial lengthening of enterocyte microvilli, increasing 4.8-fold in length within 24 h, and the maintaining of that length through digestion. Beginning at 24 h postfeeding, spherical particles were found embedded apically within enterocytes of the proximal and middle small intestine. These particles possessed an annular-like construction and were stained with the calcium-stain Alizarine red S suggesting that they were bone in origin. Following the completion of digestion, many of the postprandial responses were reversed, as observed by the atrophy of enterocytes, the shortening of villi, and the retraction of the microvilli. Further exploration of the python intestine will reveal the underlying mechanisms of these trophic responses and the origin and fate of the engulfed particles.     

The anatomicohistological characteristics of the formation of the mucosa of the human small intestine in the prenatal period of ontogeny]

The time, when the first villi appear, is defined. Quantitative composition, percent content, height of the villi of the mucous membrane in all parts of the small intestine during various periods of the intrauterine development are presented. In 17-week-old embryos at the level of the duodenum the first villi are noted and their formation in the middle part of the intestinal tube is revealed. By the 8th-9th weeks of development they appear at the level of the caudal part of the intestine. This demonstrates asynchronism of their formation in the cranio-caudal direction. The periods of their intensive growth in height in the first part of the intestine correspond to 8-10, 12-16, 24 weeks of the fetus age, in the second part--to 8-10, 18-20 weeks, in the third--to 10-12, 16-18, 26-28 weeks. These periods alternate with an abatement in growth intensity, which is connected with an increasing width of the villi themselves, with amount of newly formed villi and with changes of the intestinal tube diameter. The form of the villi is rather variable.     

Transmural Intestinal Wall Permeability in Severe Ischemia after Enteral Protease Inhibition

In intestinal ischemia, inflammatory mediators in the small intestine''s lumen such as food byproducts, bacteria, and digestive enzymes leak into the peritoneal space, lymph, and circulation, but the mechanisms by which the intestinal wall permeability initially increases are not well defined. We hypothesize that wall protease activity (independent of luminal proteases) and apoptosis contribute to the increased transmural permeability of the intestine''s wall in an acutely ischemic small intestine. To model intestinal ischemia, the proximal jejunum to the distal ileum in the rat was excised, the lumen was rapidly flushed with saline to remove luminal contents, sectioned into equal length segments, and filled with a tracer (fluorescein) in saline, glucose, or protease inhibitors. The transmural fluorescein transport was determined over 2 hours. Villi structure and epithelial junctional proteins were analyzed. After ischemia, there was increased transmural permeability, loss of villi structure, and destruction of epithelial proteins. Supplementation with luminal glucose preserved the epithelium and significantly attenuated permeability and villi damage. Matrix metalloproteinase (MMP) inhibitors (doxycycline, GM 6001), and serine protease inhibitor (tranexamic acid) in the lumen, significantly reduced the fluorescein transport compared to saline for 90 min of ischemia. Based on these results, we tested in an in-vivo model of hemorrhagic shock (90 min 30 mmHg, 3 hours observation) for intestinal lesion formation. Single enteral interventions (saline, glucose, tranexamic acid) did not prevent intestinal lesions, while the combination of enteral glucose and tranexamic acid prevented lesion formation after hemorrhagic shock. The results suggest that apoptotic and protease mediated breakdown cause increased permeability and damage to the intestinal wall. Metabolic support in the lumen of an ischemic intestine with glucose reduces the transport from the lumen across the wall and enteral proteolytic inhibition attenuates tissue breakdown. These combined interventions ameliorate lesion formation in the small intestine after hemorrhagic shock.     

Prenatal intestinal histology and histochemistry in the goat

The mucosa of the small and large intestine of goat fetuses exhibited villi which had disappeared after the 32.5-cm curved crown rump (CVR) stage. At places, the stratified epithelial lining persisted among the normal columnar epithelium with goblet cells. The concentration of goblet cells increased with age, while the thickness of the epithelium decreased. The crypts of Lieberkühn were tortuous at the base. Brunner's glands appeared at the 14.2-cm CVR stage. Peyer's patches appeared at the 24.5-cm CVR stage in the ileum. The muscularis mucosae differentiated in the large intestine in group II (16.2- to 24.5-cm CVR length) and progressed caudocranially. The striated border of the intestinal epithelium presented with alkaline phosphatase activity; this border and the goblet cells also stained for mucin. Glycogen was demonstrable in the epithelium with greater concentrations in the duodenum and jejunum in group I (11.5- to 14.6-cm CVR length), and in the ileum and large intestine in group III (30.8- to 39.5-cm CVR length).