AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and tre...AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine,butyrate,or saline.Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure.Follow-up colonoscopy was performed every 4 wk for 12 wk.The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β,tumor necrosis factor-alpha,and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay.RESULTS:Colonoscopies of the diverted segment showed mucosa with hyperemia,increased number of vessels,bleeding and mucus discharge.Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic(P < 0.02) and histological scores(P < 0.01) and restored the densities of collagen fibers in tissue(P = 0.015;P = 0.001),the number of goblet cells(P = 0.021;P = 0.029),and the rate of apoptosis within the epithelium(P = 0.043;P = 0.011) to normal values.The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine.CONCLUSION:The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.展开更多
The purpose of this paper is to investigate a novel power cycle using low-temperature heat sources such as oceanic-thermal, biomass as well as industrial waste heat. Both a reheater and a liquid-gas ejector are used i...The purpose of this paper is to investigate a novel power cycle using low-temperature heat sources such as oceanic-thermal, biomass as well as industrial waste heat. Both a reheater and a liquid-gas ejector are used in this ammonia-water based cycle. Energy analysis and parametric analysis are performed to guide the theoretical performance and experimental investigation is done to verify the theoretical results. The results show that the generator pressure, heating source temperature and turbine outlet depressurization made by the ejector can affect the cycle performances. Besides, the experimental thermal efficiency is much lower than the theoretical one on account of the heat losses and irreversibility. Moreover, the performance of liquid-gas ejector is affected by primary flow pressure and temperature.展开更多
基金Supported by Grants from the Brazilian Research CouncilFundao de Amparo à Pesquisa do Estado do Rio de Janeiro
文摘AIM:To investigate whether butyrate or glutamine enemas could diminish inflammation in experimental diversion colitis.METHODS:Wistar specific pathogen-free rats were submitted to a Hartmann's end colostomy and treated with enemas containing glutamine,butyrate,or saline.Enemas were administered twice a week in the excluded segment of the colon from 4 to 12 wk after the surgical procedure.Follow-up colonoscopy was performed every 4 wk for 12 wk.The effect of treatment was evaluated using video-endoscopic and histologic scores and measuring interleukin-1β,tumor necrosis factor-alpha,and transforming growth factor beta production in organ cultures by enzyme linked immunosorbent assay.RESULTS:Colonoscopies of the diverted segment showed mucosa with hyperemia,increased number of vessels,bleeding and mucus discharge.Treatment with either glutamine or butyrate induced significant reductions in both colonoscopic(P < 0.02) and histological scores(P < 0.01) and restored the densities of collagen fibers in tissue(P = 0.015;P = 0.001),the number of goblet cells(P = 0.021;P = 0.029),and the rate of apoptosis within the epithelium(P = 0.043;P = 0.011) to normal values.The high levels of cytokines in colon explants from rats with diversion colitis significantly decreased to normal values after treatment with butyrate or glutamine.CONCLUSION:The improvement of experimental diversion colitis following glutamine or butyrate enemas highlights the importance of specific luminal nutrients in the homeostasis of the colonic mucosa and supports their utilization for the treatment of human diversion colitis.
基金supported by the National Natural Science Foundation of China (Grant No. 51076146)
文摘The purpose of this paper is to investigate a novel power cycle using low-temperature heat sources such as oceanic-thermal, biomass as well as industrial waste heat. Both a reheater and a liquid-gas ejector are used in this ammonia-water based cycle. Energy analysis and parametric analysis are performed to guide the theoretical performance and experimental investigation is done to verify the theoretical results. The results show that the generator pressure, heating source temperature and turbine outlet depressurization made by the ejector can affect the cycle performances. Besides, the experimental thermal efficiency is much lower than the theoretical one on account of the heat losses and irreversibility. Moreover, the performance of liquid-gas ejector is affected by primary flow pressure and temperature.
