The cell population of the upper jejunal mucosa in tropical sprue and postinfective malabsorption

The cell population of the upper jejunal mucosa has been studied in cases of tropical sprue from the Far East and Middle East, and in similar cases arising in western Europe (`post-infective malabsorption'), and compared with cases of untreated coeliac disease and patients without small bowel disease.

Infiltration of the epithelial layer of the upper jejunal mucosa by lymphocytes was found in tropical sprue to the same extent as in coeliac disease, and, to a lesser extent, in `postinfective malabsorption'.

In the lamina propria, in all forms of acute sprue there was an increased density of lymphocytes. With increasing duration and with increasing mucosal atrophy, the lymphocytes were progressively replaced by plasma cells, and the cellular infiltration in chronic sprue was indistinguishable from that of coeliac disease.

The findings suggest that a humoral antibody response is a feature of sprue, and becomes more prominent as the condition becomes chronic.

     

Three-dimensional reconstruction of jejunal biopsy in tropical sprue

There is a lot of diversity in the observations on jejunal histology between light and dissection microscopy in tropical sprue. In order to compare the light and dissection microscopic appearances, a three-dimensional model of the villous pattern was constructed after a study of 350 serial sections of jejunal biopsy from a patient with tropical sprue. There was considerable variation in the morphological appearance of the villi in different sections. The changes seen varied from mild to partial villous atrophy. Broad synechia and bridge formation between adjoining villi due to fusion was frequently observed. It is postulated that the process of fusion of villi may be partly responsible for the development of features of partial villous atrophy seen in jejunal biopsies in tropical sprue. Normal jejunal pattern reported by some workers in patients with tropical sprue could possibly be due to inadequate sampling of the total biopsy piece.     

Quantitation of immunoglobulin-containing cells in the jejunal lamina propria in tropical sprue.

Ten patients with tropical sprue (TS) and 10 with irritable bowel syndrome (IBS) as controls were studied to characterize the immunocytes in the jejunal mucosa. IgA cells numbered 516,155 +/- 48,715 cells/mm3 in TS and 729,308 +/- 146,011/mm3 in the IBS patients. IgG cell counts were 28,885 +/- 8,081/mm3 in TS and 10,615 +/- 4,100/mm3 in IBS; IgM counts were 170,729 +/- 25,015/mm3 in TS and 169,253 +/- 45,353/mm3 in IBS. A positive correlation was present between IgM-bearing plasma cells and corresponding serum immunoglobulins (r = +0.71; p less than 0.05). No correlation was evident between the different immunocytes (IgA, IgG, and IgM) and the duration of illness, serum albumin, and tests for absorption of fat, B-12, and D-xylose (p greater than 0.05). The gut immunocytes expressed in absolute numbers were higher in our controls and TS patients than reported in Western populations.     

Epithelial cell turnover and apoptosis

The homeostasis of gastric epithelial cells is maintained by the balance between cell proliferation and apoptosis. Alterations of these physiological cellular events in chronic pathological conditions of the stomach. As far as the proliferative pattern is concerned, an increase in the total number of epithelial proliferating cells and an abnormal distribution of the latter are frequently observed in chronic gastritis, gastric atrophy, intestinal metaplasia, gastric dysplasia and gastric cancer. Conversely, apoptosis has been found to be impaired in intestinal metaplasia, gastric dysplasia and cancer. Helicobacter pylori infection is associated with changes in epithelial-cell turnover, though their significance in gastric carcinogenesis is still controversial. An increase in overall epithelial cell proliferation and the upward shift of replicating cells toward the superficial part of the gastric pits are patterns usually observed during Helicobacter pylori infection and these changes can be reversed by successful eradication of the infection. However, it seems that this reversibility will be lost during progression through the steps of gastric carcinogenesis, such as intestinal metaplasia, probably representing the phenotypic expression of the true initiating phase of the carcinogenetic process. The influence of Helicobacter pylori infection on gastric epithelial apoptosis in humans is still controversial, since different results having been obtained by different authors. It seems that cagA status influences the effect of Helicobacter pylori on epithelial apoptosis, so that a different cagA make-up of the studied groups could explain these conflicting results. However, further studies are needed to elucidate this issue in humans.     

Absorption of water and sodium and activity of adenosine triphosphatases in the rectal mucosa in tropical sprue.

In 10 southern Indian patients with tropical sprue, in vivo dialysis showed a defect of absorption of water and sodium from the rectum, when compared with 11 healthy volunteers. Sodium-potassium-ATPase activity, measured in homogenates of rectal biopsies, was significantly diminished in patients with sprue. Magnesium-ATPase and alkaline phosphatase were normal in biopsy homogenates. Decreased activity of colonic sodium-potassium-ATPase may contribute to diarrhoea in some patients with tropical sprue.     

Epithelial cell turnover in relation to ongoing damage of the gastric mucosa in patients with early gastric cancer: increase of cell proliferation in paramalignant lesions

Background Gastric cancer is typically an end result of Helicobacter pylori-associated chronic gastritis. The pathogenesis is thought to involve effects on gastric mucosal epithelial cell turnover. In this study, we aimed to compare apoptosis and proliferation in the noncancer-containing mucosa of H. pylori-positive patients with early gastric cancer with these phenomena in H. pylori-positive controls.Methods Two specimens each were obtained from the greater and lesser curvatures of the corpus and from the greater curvature of the antrum. The histopathological grading used was the updated Sydney System. Apoptotic epithelial cells were detected using the terminal deoxy nucleotidyl transferase-mediated deoxy-uridine triphosphate (dUTP) biotin nick-end labeling (TUNEL) method. The expression of Ki 67 was evaluated by immunostaining.Results Forty-five H. pylori-positive patients with endoscopic mucosal resection for early gastric cancer and 52 H. pylori-positive controls were studied. Gastric cancer was associated with a higher frequency of incomplete intestinal metaplasia (IM; odds ratio [OR], 19.1; 95% confidence interval [CI], 6.9–53.2; P < 0.001). The apoptotic index (AI) in the greater curvature of the corpus and the proliferation index (PI) in each part were significantly higher in cancer patients than in the control group. The median PI in the antrum was significantly higher in the incomplete IM group than that in the complete IM group (17.6 vs 12.6; P = 0.009). The PI and the AI in the greater curvature of the corpus correlated with the activity score, and the PI correlated with the IM score.Conclusions In the cancer patients, H. pylori-induced gastritis was associated with increased cell proliferation and apoptosis compared with mucosal findings in the controls. IM seems to be one of the most important factors affecting cell proliferation and may be one of the components of carcinogenesis that results in proliferation-dominant cell kinetics.     

In vitro sensitization and mast cell degranulation in human jejunal mucosa.

Sera from 3 allergic patients with specific IgE antibodies as shown by RAST were used to sensitize jejunal mucosa obtained from surgical patients. The sensitized specimens were challenged with the appropriate antigens to the specific IgE shown in the sera, Non-challenged sensitized specimens were used as controls to determine mast cell degranulation. The mast cells were counted in a defined area in the mucosa immediately adjacent to the muscularis mucosa. Mast cell degranulation was 47 percent in a timothy pollen system, 40 percent in an eggwhite system, and 33 percent in a codfish system. The results of the investigation indicates that mast cells in the human jejunal mucosa are able to react in the same manner as mast cells in the human lung. The experimental model described appears suitable for studying the allergic reaction in the gastrointestinal tract and the effect of pharmacotherapy in this respect.     

Rectal mucosal morphologic abnormalities in normal subjects in southern India: a tropical colonopathy?

Electron dense bodies and vesicles were increased in undifferentiated crypt cells and differentiated colonocytes in the rectal mucosa of healthy volunteers in southern India. In addition, in the surface colonocytes lysosomes were increased, the cells were shorter with short irregularly grouped microvilli, there was evidence of cell immaturity and a high prevalence of spiral organism infestation. There was also alterations in goblet cell mucus granules, a reticulohistiocytic response in the subluminal lamina propria and residual evidence of vascular damage. These alterations indicate a non-specific response to mucosal injury. Such changes have not been observed in the rectal mucosa of temperate zone controls and could be designated tropical colonopathy.     

Salivary and gastric secretions in patients with tropical sprue

Salivary secretions on mechanical stimulation with forced spitting method and on chemical simulation with 10% citric acid and gastric acid secretions on maximal histamine stimulation were studied in 20 adults with tropical sprue and 20 adult control subjects. It was observed that the chemical method provided a better stimulus than the mechanical one in both groups. The salivary flow rates as well as salivary amylase, pH, sodium and potassium were similar in both groups. Tropical sprue patients, however, had significantly lower maximal acid output as compared to normals. It was concluded that, although tropical sprue patients are known to have widespread damage to alimentary tract mucosa, salivary glands do not seem to be involved.     

Morphological changes of cell proliferation and apoptosis in rat jejunal mucosa at different ages

AIM: To study the changes of cell proliferation and apoptosis in rat jejunal epithelium at different ages. METHODS: Cell proliferation and apoptosis of the jejunal mucosal and glandulous epithelia from birth to postnatal 12(th) month were observed using immunocytochemistry (ICC), and TUNEL method. The height of villus, the thickness of muscle layer and the number of goblet cells in jejunal mucosal and glandulous epithelia were measured by BeiHang analytic software and analyzed by STAT. RESULTS: (1) Proliferating cell nuclear antigen (PCNA) positive cells of jejunal glandulous recess were found and increased in number from birth to the postnatal 3(rd) month. The number of PCNA positive cells peaked in the postnatal 3(rd) month, and decreased from then on. (2) The number of apoptotic cells also peaked in the postnatal 3(rd) month, showing a similar trend to that of the PCNA positive cells. (3) The height of jejunal villus increased after birth, peaked in the postnatal 3(rd) month and decreased from then on. The jejunal muscle layer became thicker in the postnatal 3(rd) week and the postnatal 12(th) month. The number of goblet cells of the jejunal mucosal and glandulous epithelia had a linear correlation with age. CONCLUSION: (1) PCNA positive cells are distributed in the jejunal glandulous recess. (2) Apoptotic cell number peaks in the postnatal 3(rd) month, indicating that cell proliferation and apoptosis are developed with the formation of digestive metabolism as rat grows to maturity. (3) The thickness of jejunal muscle layer increases to a maximum in the postnatal 3(rd) week, which may be related to the change in diet from milk to solid food. (4) The number of goblet cells increases rapidly in the postnatal 3(rd) week, probably due to ingestion of solid food.