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V N Nichols

Publications and source records attributed to V N Nichols.

5 recordsLinked to original sources
PubMed1992

Mosaic expression of brush-border enzymes in infants with chronic diarrhea and malnutrition.

The chronic diarrhea observed in young malnourished infants that is sensitive to dietary glucose and other carbohydrates is associated with variable degrees of patchy mucosal villous atrophy. To explore intrinsic mucosal function in the pathogenesis of this alimentary intolerance, we have conducted an immunohistologic investigation of brush-border enzyme proteins of clinically obtained, mucosal biopsy samples. We used a group of monoclonal antibodies against human brush-border aminopeptidase, sucrase/isomaltase (SI), maltase, and lactase enzyme proteins. SI was strongly and uniformly expressed in crypts and villi of 11 of the 14 subjects; in 3 subjects, however, SI was expressed in a mosaic pattern. Maltase and lactase were occasionally absent, but more commonly were expressed in a mosaic distribution. The mosaic expression of brush-border enzyme proteins has been reported in congenital enzyme deficiencies associated with normal intestinal histology. We report the mosaic expression of brush-border enzyme proteins as a functional alteration associated with a pathological lesion of the mucosa in infants with chronic diarrhea. Our observation challenges the existing concept of ontogenic regulation of brush-border enzyme activity.

Aminopeptidases↗
PubMed1990

Pathogenesis of small-intestinal mucosal lesions in chronic diarrhea of infancy: I. A light microscopic study.

In an effort to increase our understanding of the pathogenesis of chronic protracted diarrhea in infants, we examined 44 jejunal mucosal specimens. Only 3 of the 44 specimens showed a normal mucosa (grade 1). Partial villous atrophy was seen in 17 mucosal specimens (grade 2) with marked patchiness in all of the specimens. Subtotal or total villous atrophy (grade 3) was found in the remaining 24 mucosal biopsies. Plasma cells and macrophages were variably increased and intraepithelial lymphocytes were moderately increased in grades 2 and 3. Eight of ten mucosal biopsy specimens embedded in plastic material and cut at 1-2-mm thickness, showed bacteria of unidentified nature, situated either above the microvillous layer or on the mucosal surface. Both adherent and nonadherent bacteria could be identified in the same specimen. We concluded that severe pathological mucosal changes are common in young infants with protracted diarrhea and that the presence of bacteria may be more common than has previously been documented.

Atrophy↗
PubMed1990

Pathogenesis of small-intestinal mucosal lesions in chronic diarrhea of infancy: II. An electron microscopic study.

Our electron microscopic study of biopsies taken from 10 infants with protracted diarrhea was conducted in an effort to determine the pathogenesis of the disorder. In this article, the ultrastructure of the jejunal mucosa of the infants is described in relation to overlying or adherent bacteria of unidentified type. In addition to the known changes on the enterocyte surface caused by adherent bacteria (cupping and effacement), other cytopathic changes, not previously reported, are documented. Included are widespread loss of enterocytes, including intraepithelial lymphocytes, into the bowel lumen; cytopathological changes within the enterocytes; and marked thickening of the basal laminae of the enterocytes and the endothelium of lamina propria blood vessels. In addition, we noted deposition of collagen fibrils in the lamina propria below the basal laminae, active phagolysis within macrophages, and lack of cisternal material (immunoglobulin) in the plasma-cell cytoplasm. Although these changes are nonspecific, they may be related in part to the presence of the nonadhering and adhering bacteria, and their identification may further our understanding of the "sick mucosa" that occurs in chronic diarrhea of infancy.

Bacteria↗
PubMed1979

Lactation.

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Body Water↗