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Background

Impairment of gastrointestinal motility is frequently observed in patients with severe infection.

Aim

To assess whether exposure of human colonic mucosa to pathogenic lipopolysaccharide affects smooth muscle contractility.

Methods

Human colonic mucosa and submucosa were sealed between two chambers, with the luminal side facing upwards and covered with Krebs solution, with or without lipopolysaccharide from a pathogenic strain of Escherichia coli (O111:B4; 1000 ng/mL), and with the submucosal side facing downwards into Krebs. The solution on the submucosal side was collected following 30-min mucosal exposure to Krebs without (N-undernatant) or with lipopolysaccharide (lipopolysaccharide undernatant). Undernatants were tested for lipopolysaccharide and hydrogen peroxide levels and for their effects on smooth muscle cells in the presence of catalase, indomethacin or MG132.

Results

Smooth muscle cells incubated with N-undernatant had a maximal contraction of 32 ± 5% that was reduced by 62.9 ± 12% when exposed to lipopolysaccharide undernatant. Inhibition of contraction was reversed by catalase, indomethacin and MG132. Lipopolysaccharide levels were higher in the lipopolysaccharide undernatant (2.7 ± 0.7 ng/mL) than in N-undernatant (0.45 ± 0.06 ng/mL) as well as hydrogen peroxide levels (133.75 ± 15.9 vs 82 ± 7.5 nM respectively).

Conclusions

Acute exposure of colonic mucosa to pathogenic lipopolysaccharide impairs muscle cell contractility owing to both lipopolysaccharide mucosal translocation and production of free radicals.  相似文献   
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Climate change would have a range of impacts on human health. Health impacts would be caused by the direct effect of climatic factors on human health, such as heat stress, and possible changes in the frequency and intensity of extreme weather events such as storms, floods and droughts. Impacts on health would also be mediated by the indirect effects of climate change, such as changes in availability of food and water and the distribution of vector‐borne diseases. The majority of health impacts would be adverse and would depend greatly on the vulnerability of populations.  相似文献   
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The Health Reach Sri Lanka project (1993–96) is described. It was a school‐based assessment of children's exposure to war‐related events and the presence of psychological distress, undertaken in six communities in parts of Sri Lanka variously affected by armed conflict. Its objectives, methods and results are presented. The research project aimed to raise national awareness of the psychosocial effects of armed conflict on children, using a community‐development approach to local capacity building, based on the ‘health initiative as peace initiative’ model. As a follow‐up to the study, a locally run programme, based on creative play and trauma‐healing, was established, initially for the children involved in the study. This was later extended to other children in the district affected by armed conflict.  相似文献   
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