AIM: To investigate the effect of lipopolysaccharide (LPS)on the diarrheogenic activity, gastrointestinal transit (GIT),and intestinal fluid content and the possible role of nitric oxide (NO) and prostaglandin E2 (PGE...AIM: To investigate the effect of lipopolysaccharide (LPS)on the diarrheogenic activity, gastrointestinal transit (GIT),and intestinal fluid content and the possible role of nitric oxide (NO) and prostaglandin E2 (PGE2) in gastrointestinal functions of endotoxin-treated mice.METHODS: Diarrheogic activity, GIT, and intestinal fluid content as well as nitric oxide and PGE2 products were measured after intraperitoneal administration of LPS in mice.RESULTS: LPS dose-dependently accumulated abundant fluid into the small intestine, induced diarrhea, but decreased the GIT. Both nitric oxide and PGE2 were found to increase in LPS-treated mice. Western blot analysis indicated that LPS significantly induced the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in mice intestines. Pretreatment with NG-nitro-L-arginine-methyl ester (L-NAME, a non-selective NOS inhibitor) or indomethacin (an inhibitor of prostaglandin synthesis) significantly attenuated the effects of LPS on the diarrheogenic activity and intestine content, but reversed the GIT.CONCLUSION: The present study suggests that the pathogenesis of LPS treatment may mediate the stimulatory effect of LPS on nitric oxide and PGE2 production and NO/prostaglandin pathway may play an important role on gastrointestinal function.展开更多
AIM: To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG) in cecectomized rats. METHODS: S was dissolved either in distilled water or in RG (50 g/L) and ingeste...AIM: To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG) in cecectomized rats. METHODS: S was dissolved either in distilled water or in RG (50 g/L) and ingested as a single oral dose (1.2 g/kg body mass, containing 0.5 g/L phenol red as a re-covery marker) by S (control) and S + RG groups (n = 7), respectively. This dose is over the laxative dose for hu-mans. Animals were sacrificed exactly 1 h after dose in-gestion, without any access to drinking water. The whole gastro-intestinal tract was divided into seven segments and sampled to analyze the S and marker remaining in its contents.RESULTS: Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3rd and last quarter of the small intestine (24.85 ± 18.88% vs 0.0 ± 0.0% and 39.09 ± 32.75% vs 0.0 ± 0.0%, respectively, P < 0.05) was sig-nificantly higher in the S + RG group than in the control group. The S absorption index and the intestinal fluid volume are inversely related to each other. CONCLUSION: The intestinal mal-absorption of S is the main reason for S-based osmotic diarrhea. Where RG en-hanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.展开更多
A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign am...A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign amebomas caused by invasive Entamoeba histolytica,which regressed completely with medical therapy.In Western countries,the occurrence of invasive protozoan infection with formation of amebomas is very rare and can mistakenly masquerade as a neoplasm.Not surprisingly,there have been very few cases reported of this clinical entity within the United States.Moreover,we report a patient that had an extremely rare occurrence of two synchronous lesions,one involving the rectum and the other situated in the cecum.We review the current literature on the pathogenesis of invasive E.histolytica infection and ameboma formation,as well as management of this rare disease entity at a western medical center.展开更多
基金Supported by the National Science Council of Taiwan (NSC 92-2320-B-038-027) the Min-Sheng Healthcare (93MSH-TMU-006)
文摘AIM: To investigate the effect of lipopolysaccharide (LPS)on the diarrheogenic activity, gastrointestinal transit (GIT),and intestinal fluid content and the possible role of nitric oxide (NO) and prostaglandin E2 (PGE2) in gastrointestinal functions of endotoxin-treated mice.METHODS: Diarrheogic activity, GIT, and intestinal fluid content as well as nitric oxide and PGE2 products were measured after intraperitoneal administration of LPS in mice.RESULTS: LPS dose-dependently accumulated abundant fluid into the small intestine, induced diarrhea, but decreased the GIT. Both nitric oxide and PGE2 were found to increase in LPS-treated mice. Western blot analysis indicated that LPS significantly induced the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 in mice intestines. Pretreatment with NG-nitro-L-arginine-methyl ester (L-NAME, a non-selective NOS inhibitor) or indomethacin (an inhibitor of prostaglandin synthesis) significantly attenuated the effects of LPS on the diarrheogenic activity and intestine content, but reversed the GIT.CONCLUSION: The present study suggests that the pathogenesis of LPS treatment may mediate the stimulatory effect of LPS on nitric oxide and PGE2 production and NO/prostaglandin pathway may play an important role on gastrointestinal function.
文摘AIM: To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG) in cecectomized rats. METHODS: S was dissolved either in distilled water or in RG (50 g/L) and ingested as a single oral dose (1.2 g/kg body mass, containing 0.5 g/L phenol red as a re-covery marker) by S (control) and S + RG groups (n = 7), respectively. This dose is over the laxative dose for hu-mans. Animals were sacrificed exactly 1 h after dose in-gestion, without any access to drinking water. The whole gastro-intestinal tract was divided into seven segments and sampled to analyze the S and marker remaining in its contents.RESULTS: Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3rd and last quarter of the small intestine (24.85 ± 18.88% vs 0.0 ± 0.0% and 39.09 ± 32.75% vs 0.0 ± 0.0%, respectively, P < 0.05) was sig-nificantly higher in the S + RG group than in the control group. The S absorption index and the intestinal fluid volume are inversely related to each other. CONCLUSION: The intestinal mal-absorption of S is the main reason for S-based osmotic diarrhea. Where RG en-hanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.
文摘A 54-year-old man presented with rectal pain and bleeding secondary to ulcerated,necrotic rectal and cecal masses that resembled colorectal carcinoma upon colonoscopy.These masses were later determined to be benign amebomas caused by invasive Entamoeba histolytica,which regressed completely with medical therapy.In Western countries,the occurrence of invasive protozoan infection with formation of amebomas is very rare and can mistakenly masquerade as a neoplasm.Not surprisingly,there have been very few cases reported of this clinical entity within the United States.Moreover,we report a patient that had an extremely rare occurrence of two synchronous lesions,one involving the rectum and the other situated in the cecum.We review the current literature on the pathogenesis of invasive E.histolytica infection and ameboma formation,as well as management of this rare disease entity at a western medical center.
