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G J Dammin

Publications and source records attributed to G J Dammin.

6 recordsLinked to original sources
PubMed1976

Fluid and electrolyte transport in rhesus monkeys challenged intracecally with Shigella flexneri 2a.

Shigella flexneri 2a is an invasive enteric pathogen that may produce diarrhea when ingested by human beings and subhuman primates. We have previously shown that shigella diarrhea correlates with water and electrolyte transport abnormalities in the jejunum and colon. Dysentery alone is associated only with colonic transport abnormalities. To define the relationship between invasion and inflammation of the colon and the occurrence of jejunal transport abnormalities, we studied water and electrolyte transport, histology, and bacteriology in rhesus monkeys that were infected by introducing S. flexneri 2a directly into the cecum. In contrast to the pattern of disease seen after oral administration, cecal inoculation resulted in clinical disease in 64% of animals, of which 94% manifested dysentery alone, rarely preceded by mild diarrhea. Histologically, invasion and inflammation was limited to the colon. Secretion of water and sodium occurred in the colon of infected monkeys when compared with controls, whereas transport was normal in the jejunum and ileum. These data further demonstrate that severe dysentery can result from cecal injection of shigellae, but also suggest that the occurrence of watery diarrhea requires and may result from an undefined interaction between the jejunal mucosa and the organisms during transit through the small intestine.

Animals↗
PubMed1976

The role of altered intestinal permeability in the pathogenesis of salmonella diarrhea in the rhesus monkey.

The pathogenesis of Salmonella diarrhea is unclear. Bacterial invasion of the ileal and colonic mucosa resulting in an intense ileocolitis regularly occurs in concert with secretion of water and sodium in jejunum, ileum, and colon. To examine the role of altered permeability in Salmonella diarrhea we studied intestinal histology, water and electrolyte transport, clearance of intravenously injected [14C]erythritol and [3H]mannitol, and changes in transmural electrical potential difference in normal and Salmonella-infected rhesus monkeys. In normal animals, absorption of water and sodium occurred in jejunum, ileum, and colon and a gradient of diminishing permeability from jejunum to ileum to colon for both erythritol and mannitol was observed. Permeability as measured by determining permeability coefficients was not increased by Salmonella infection and in fact was significantly reduced for erythritol in the jejunum of infected animals. Perfusion with hypertonic erythritol and mannitol produced the same streaming potentials (deltaPD) in control and infected animals, indicating no differences in transmucosal permeability. As a positive control, perfusion with 25 mM ethylenediaminetetraacetic acid in normal animals increased permeability, resulting in increased plasma-to-lumen isotope flux and no deltaPD in response to hypertonic perfusates. These data show that despite severe alterations in intestinal histology, transmucosal permeability remains unchanged and thus is not a contributing factor in Salmonella diarrhea.

Animals↗