Histopathological Changes in Small Intestine of Rotavirus Infected Poultry

Background: Rotaviruses are important cause of acute gastroenteritis. Group A and D rotavirus are the predominant enteric viruses groups in birds. Outbreaks of rotavirus may lead to significant economic losses in poultry industry. Rotavirus infection alters the function of the small intestinal epithelium, resulting in diarrhea. Methods: Poultry intestinal samples were collected in 10% formalin and duodenum, jejunum and ileum were processed for histopathological examination by H and E staining. Result: Histopathological changes were noticed in all the three parts of the small intestine namely duodenum, jejunum and ileum in poultry intestinal content sample positive for AvRVD in RT-PCR. Duodenum showed necrosis, desquamation and loss of enterocytes from the villi. The jejunum showed severe disruption of villous architecture with vacuolation and separation of mucosal epithelial layer. Ileum showed a complete loss of enterocytes from the villous surface, congestion at the villous tips and infiltration of lymphocytes throughout the mucosa as well as submucosa.

Utility of Tissue Transglutaminase Immunohistochemistry in Pediatric Duodenal Biopsies: Patterns of Expression and Role in Celiac Disease—A Clinicopathologic Review

Tissue transglutaminase (tTG) is a ubiquitous multifunctional protein. It has roles in various cellular processes. tTG is a major target of autoantibodies in celiac disease, and its expression by immunohistochemistry in pediatric celiac disease has not been fully examined. We studied tTG expression in 78 pediatric duodenal biopsies by utilizing an antibody to transglutaminase 2. Serum tTG was positive in all celiac cases evaluated. Serum antiserum endomysial antibody (EMA) and tTG were negative in all control subjects and in inflammatory bowel disease and eosinophilic gastroenteritis. There was a statistically significant difference between cases of celiac disease and normal controls in terms of tTG immunohistochemical staining in duodenal biopsies surface epithelium ( value = 0.0012). There was no significant statistical difference in terms of staining of the villous surface or crypt between the cases of celiac disease and cases with IBD ( value = 0.5970 and 0.5227, resp.). There was no detected correlation between serum tTG values and immunohistochemical positivity on duodenal biopsy in cases of celiac disease ( value = 1). There was no relationship between Marsh classification and positivity of villous surface for tTG ( value = 0.4955). We conclude that tTG has limited utility in diagnosis of celiac disease in pediatric duodenal biopsies.

Changes in the small intestine ofSchistosoma mansoni-infected mice fed a high-fat diet

SUMMARYThe consumption of a high-fat diet modifies both the morphology of the small intestine and experimentally tested effects of schistosomiasis mansoni. However, whether a schistosomiasis infection associated with a high-fat diet causes injury to the small intestine has never been investigated. Mice were fed either a high-fat or a standard-fat diet for 6 months and were then infected withSchistosoma mansonicercariae. Physical characteristics of the intestinal tissue (mucosal thickness, small intestinal villi length and height, and abundance of goblet cells and enterocytes on the villous surface) and the distribution of granulomas along the intestinal segments and their developmental stage were measured at the time of sacrifice (9 or 17 weeks post-infection). The group fed a high-fat diet exhibited different granuloma stages, whereas the control group possessed only exudative granulomas. The chronically infected mice fed a high-fat diet exhibited higher granuloma and egg numbers than the acutely infected group. Exudative, exudative/exudative-productive and exudative-productive granulomas were present irrespective of diet. Computer-aided morphometric analysis confirmed that villus length, villus width, muscular height and submucosal height of the duodenal and jejunal segments were affected by diet and infection. In conclusion, a high-fat diet and infection had a significant impact on the small intestine morphology and morphometry among the animals tested.

FIBRIN-TYPE FIBRINOID IN HUMAN PLACENTA: A STEREOLOGICAL ANALYSIS OF ITS ASSOCIATION WITH INTERVILLOUS VOLUME AND VILLOUS SURFACE AREA

Stereological methods were used to examine fibrin-type fibrinoid deposition in the intervillous spaces of human placentas collected during gestation (12-41 weeks) and from term pregnancies at low (400 m) and high (3.6 km) altitude. The main aim was to test predictions about the relationships between fibrinoid deposits and either the volume of intervillous space or the surface area of (intermediate + terminal) villi. Fields of view on Masson trichrome-stained paraffin sections were selected as part of a systematic sampling design which randomised section location and orientation. Relative and absolute volumes were estimated by test point counting and surfaces by intersection counting. Apparent differences were tested by analyses of variance and relationships by correlation and regression analysis. Fibrinoid volume increased during gestation and correlated positively with intervillous volume and villous surface area. However, relative to intervillous volume, the main increase in fibrinoid occurred towards term (36-41 weeks). At high altitude, placentas contained more intervillous space but less fibrinoid. At both altitudes, there were significant correlations between fibrinoid volume and villous surface area. In all cases, changes in fibrinoid volume were commensurate with changes in villous surface area. Whilst findings lend support to the notion that fibrinoid deposition during normal gestation is influenced by the quality of vascular perfusion, they also emphasise that the extent of the villous surface is a more generally important factor. The villous surface may influence the steady state between coagulation and fibrinolysis since some pro-coagulatory events operate at the trophoblastic epithelium. They occur notably at sites of trophoblast de-epithelialisation and these arise following trauma or during the extrusion phase of normal epithelial turnover.

Greater vascularity, lowered HIF-1/DNA binding, and elevated GSH as markers of adaptation to in vivo chronic hypoxia

Vascularity is increased in placentas from high- compared with low-altitude pregnancies. An angiogenic response to hypoxia may protect an organ from further hypoxic insult by increasing blood flow and oxygen delivery to the tissue. We hypothesized that increased placental vascularity is sufficient to adapt to high altitude. Therefore, indexes of hypoxic stress would not be present in placentas from successful high-altitude pregnancies. Full-thickness placental biopsies were 1) collected and frozen in liquid nitrogen within 5 min of placental delivery and 2) fixed in formalin for stereologic analyses at high (3,100 m, n = 10) and low (1,600 m, n = 10) altitude. Hypoxia-inducible transcription factor (HIF-1) activity was analyzed by ELISA. Western blot analyses were used to evaluate HIF-1α, HIF-1β, HIF-2α, von Hippel-Lindau protein, VEGF, Flt-1, enolase, and GAPDH. Magnetic resonance spectroscopy was used to evaluate endogenous metabolism. The ratio of placental capillary surface density to villous surface density was 70% greater at high compared with low altitude. HIF-1 activity and HIF-1-associated proteins were unchanged in placentas from high- vs. low-altitude pregnancies. Placental expression of HIF-1-mediated proteins VEGF, Flt-1, enolase, and GAPDH were unchanged at high vs. low altitude. Succinate, GSH, phosphomonoesters, and ADP were elevated in placenta from high compared with low altitude. Placentas from uncomplicated high-altitude pregnancies have greater vascularity and no indication of significant hypoxic stress at term compared with placentas from low altitude.