Pathologic findings from intestinal biopsy specimens in human cholera

The effect of alpha-trinositol on cholera toxin-induced fluid accumulation in pig (Sus scrofa domesticus) jejunum in vivo

The effect of alpha-trinositol (D-myo-inositol-1,2,6-trisphosphate) on cholera toxin-induced fluid accumulation (i.e., net fluid secretion) was studied in the pig jejunum in vivo. Cholera toxin caused a dose-dependent fluid accumulation in control experiments. Intravenous injection of alpha-trinositol produced a reduction of the response to cholera toxin with a significant maximal inhibition of 36%. However, in high concentrations of alpha-trinositol this inhibition was absent.

The effect of alpha-trinositol on cholera toxin-induced hypersecretion and morphological changes in pig jejunum

alpha-Trinositol (D-myo-inositol 1,2,6-trisphosphate, PP56) is a novel antiinflammatory drug. This study elucidates the effect of intravenous alpha-trinositol on basal and acute fluid transport and morphological changes following cholera toxin administration in pig jejunum in vivo. Using isolated jejunal tied-off loops, the fluid hypersecretory (accumulation) effect of different doses of cholera toxin was studied in pigs treated intravenously with saline added different doses (0, 4, 8, 16 and 32 mg x kg-1 x hr-1) of alpha-trinositol. Levels of alpha-trinositol, as well as stereomicroscopical, light microscopical and scanning electron microscopical morphological studies were performed. Cholera toxin evoked a dose-dependent fluid hypersecretion. Treatment with alpha-trinositol caused a dose-dependent inhibition of the cholera toxin-induced fluid hypersecretion and did not affect basal fluid absorption. The 16 mg x kg-1 x hr-1 alpha-trinositol dose gave a maximal inhibition of 36%. Morphological studies showed only minor changes following 6 hr of exposure to 20 micrograms x loop-1 cholera toxin. These changes consisted of dilation of the villus capillaries, an increase of apical membrane blebbing and a reduction of the intercellular space. Treatment with 16 mg x kg-1 x hr-1 alpha-trinositol alone did not induce any morphological changes, and did not alter the morphological changes induced by cholera toxin, which caused fluid hypersecretion and only minor acute morphological changes. In conclusion, alpha-trinositol treatment reduced cholera toxin-induced fluid hypersecretion without altering basal fluid absorption, basal morphology, or cholera toxin-induced morphological changes in pig jejunum in vivo.

Ultrastructural changes in the upper small intestinal mucosa in patients with cholera

BACKGROUND & AIMS

Small intestinal mucosal ultrastructural abnormalities were reported in a limited number of patients with cholera in the 1970s. This study extends these observations by examining distal duodenal biopsy samples from 19 patients with cholera and 10 controls.

METHODS

Endoscopic biopsy samples obtained, usually during the first 24 hours of illness, were processed for electron microscopy.

RESULTS

Widening of intercellular spaces and alteration of apical junctional complexes were prominent in the villus epithelium, whereas blebbing of microvillus border and mitochondrial changes were more prominent in the crypt epithelium. The apical junctional and intercellular space changes were not altered by oral rehydration. Degranulation of argentaffin cells, mucosal mast cells, and eosinophils; increase in neutrophil polymorphs; and changes in the enteric nerve fibers and microvasculature were also present. The extent of the changes correlated with clinical severity.

CONCLUSIONS

The differential involvement of the villus and crypt suggests that factors responsible for secretion may act differentially on surface and crypt epithelium and that both regions may contribute to secretion. The contribution of the enteric nervous system, vasculature, argentaffin cells, mucosal mast cells, eosinophils, and neutrophils in the secretory process and in determining the severity of the clinical illness must be determined by further clinical studies.

In vivo adherence and colonization of Vibrio cholerae strains that differ in hemagglutinating activity and motility

A scanning electron microscopic study was carried out to compare the in vivo pathogenicity of two strains of Vibrio cholerae in an adult rabbit ligated-gut test model. V. cholerae C5 (serotype Ogawa, biotype El Tor), a motile strain possessing hemagglutinating activity in vitro, and C21 (serotype Ogawa, classical biotype), a nonmotile strain possessing no hemagglutinating activity, were tested. Tissue samples from small intestinal loops were examined 3, 6, 9, and 12 h postinoculation. Contradictory to most published data, neither hemagglutinating activity nor motility appeared to be essential prerequisites for the pathogenesis of cholera in the experimental animal model used: nonmotile hemagglutinin-negative strain C21 adhered to and colonized the small intestine at least to the same extent as did motile hemagglutinin-positive strain C5. Maximum colonization was seen at 9 h postinoculation for both strains. C5 and C21 vibrios caused comparable damage to the villi of the small intestine. The villous epithelium showed only mild changes during the first 9 h postinoculation. However, after 12 h the epithelium was seriously damaged concomitant with a decrease in the number of vibrios. Many villi showed partial or total denudation, owing to repelled epithelium, leaving a bare basal lamina with only some to moderate numbers of vibrios attached. Since similar changes were induced by pure cholera enterotoxin, these changes were likely the result of excessive fluid accumulation. From this study it is concluded that, at least in the animal model used, factors other than hemagglutinating activity and motility may also play a role in the association of V. cholerae with the small intestinal surface.

A bioptic study of gastrointestinal mucosa in cholera patients during an epidemic in southern Italy

A histological biopsy study of gastric and jejunal mucosa of eight acute cholera patients during an epidemic in Southern Italy was carried out. The study demonstrated in all patients an intact epithelial lining of gastric and jejunal mucosa, a moderate degenerative process of enterocytes, presence of inflammatory lesions manifested by edema, vascular congestion, mononuclear cell infiltrate of lamina propria, and discharge of goblet-cells mucus. These changes reverted to normal in a few days. The authors emphasize that, contrary to cholera patients of Asiatic areas in whom an underlying chronic spruelike enteropathy is very common, the histological picture observed in Western patients may be considered more specific since Vibrio cholerae acts upon a normal intestinal mucosa.

Electron microscopic study on the jejunal mucosa in human cholera

Small intestinal mucosa obtained from six fasting patients with cholera by a peroral biopsy technique was studied with the electron microscope. The cultures of their rectal swabs were all positive for Vibrio cholerae. In the absorptive cells, large pseudopod-like cytoplasmic processes with deformed microvilli or without microvilli (blebs) projected into the intestinal lumen from the apical cell surface, interrupting the microvillous border. In the crypts some of the undifferentiated crypt cells possessed pseudopod-like cytoplasmic projections which extended into the crypt lumen. The swelling of mitochondria, the disappearance of their cristae, an increase in the number of vesicles of the Golgi apparatus, and the dilatation and vesiculation of endoplasmic reticulum were observed in the epithelial cells. The apical portion of the cells became oedematous in some of the epithelial cells. Cytoplasmic fragments enclosed by a plasma membrane, desquamated epithelial cells, cytoplasmic organelles, and secretory granules were lying free in the intestinal lumen.Marked irregular widening of the interepithelial spaces in the jejunal mucoa was observed at the midvillous area. Many cystic vacuoles were present in the cytoplasm of epithelial cells. The possibility of fluids being transported from blood vessels to intestinal lumina through the interepithelial spaces, and the significance of these pathological findings in human cholera are discussed in this study.