Microscopic colitis in children with chronic diarrhea.

Objective: The aim of the present study was to study microscopic colitis (MC) in children with special reference to its role in chronic diarrhea and changes in mucosal biopsies.

Methods: A total of 100 consecutive children ages 3 to 12 years, with nonbloody diarrhea (passage of ≥3 loose stools per day) of >12 weeks' duration were screened and 26 were enrolled in the study in which no specific etiology could be found and colonoscopy did not reveal any mucosal abnormality. Colonic biopsies were evaluated for the presence of lymphocytic colitis or collagenous colitis and those with the characteristic changes were defined to have MC (group A).

Adherent Escherichia coli in colorectal mucosal biopsies: a histological and ultrastructural evaluation.

Background: Colorectal mucosal biopsies occasionally demonstrate the presence of bacteria adherent to the epithelium. This study evaluated the histological and ultrastructural correlates of such bacterial adherence.

Materials And Methods: Rectal mucosal biopsies from eight patients in whom histopathological examination of biopsies had earlier demonstrated adherent bacteria were examined by electron microscopy and by bacterial culture.

Risk of colorectal cancer in ulcerative colitis in India.

Background: The risk for colorectal cancer (CRC) in ulcerative colitis (UC) in India is not known.

Method: Retrospective cohort from a tertiary level hospital in South India. Analysis of archived records of all patients with UC who underwent colonoscopy and segmental biopsies over the last 25 years.

Effects of zinc supplementation as adjunct therapy on the systemic immune responses in shigellosis.

Background: Zinc is lost during diarrheal diseases, and zinc deficiency induces intestinal morphology-altering inflammatory responses that zinc supplementation can correct.

Objective: We assessed the in vivo effect of zinc supplementation on systemic and mucosal responses in mildly to moderately malnourished (defined as <-1 but >-2 and <-2 but >-3 weight-for-height z scores, respectively, based on the National Center for Health Statistics growth reference) children with shigellosis.

Design: A double-blind placebo-controlled trial was conducted in Shigella flexneri-infected children aged 12-59 mo.

Vascular changes in duodenal mucosa in shigellosis and cholera.

Vascular endothelial cells are highly specialized cells with numerous sensory and modulator functions. Our previous studies show extensive microvascular changes in rectal mucosal vasculature of patients with acute infective diarrhea (Mathan and Mathan 1985a, Gut 26:710-717). We looked for changes in the duodenal mucosal vasculature in two naturally occurring diarrheal infections: shigellosis and cholera.

Persistence of mucosal mast cells and eosinophils in Shigella-infected children.

Cells of the innate immune system and their mediators were studied at the single-cell level in the rectums of pediatric and adult patients with Shigella infection to better understand why children are at higher risk for severe infection. Adult patients had increased infiltration of mucosal mast cells (MMC) at the acute stage (3 to 5 days after the onset of diarrhea) and eosinophils in early convalescence (14 to 16 days after onset). Increased expression of stem cell factor and prostaglandin H synthase-1 (PGHS-1) was associated with increased tryptase-K(i)67-double-positive MMC in the acute stage and increased apoptosis of MMC, which led to a rapid decline in early convalescence.

Adaptive and inflammatory immune responses in patients infected with strains of Vibrio parahaemolyticus.

In patients with diarrhea caused by Vibrio parahaemolyticus, antibody-secreting cell responses to thermostable direct hemolysin (TDH), lipopolysaccharide (LPS), and whole-cell bacteria were seen. TDH- and LPS-specific responses were seen in serum samples, and immunoglobulin A antibody responses were observed in stool. Levels of C-reactive protein and nitric oxide metabolites increased in the systemic circulation at the onset of illness.

Cytoskeletal changes during poliovirus infection in an intestinal cell line.

Background & Objectives: Although polioviral replication has been extensively studied, cytoskeletal changes in the host cell during poliovirus replication have not been extensively investigated. We studied the ultrastructural and cytoskeletal changes in host cells during poliovirus infection.

Methods: Fluorescence staining of filamentous actin with a fluorescein-isothiocynate labelled mycotoxin, in the absence and presence of microfilament inhibitors cytochalasins B and D, and electron microscopy were used to investigate the role and fate of actin microfilaments during poliovirus infection, morphogenesis and release in an intestinal cell line, HRT-18.

Increased levels of inflammatory mediators in children and adults infected with Vibrio cholerae O1 and O139.

Investigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected with Vibrio cholerae O1 and V. cholerae O139. The levels of nonspecific mediators of the innate defense system, i.