Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammatio...Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcera-tive colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inex-pensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d fol-lowed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentra-tion followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.展开更多
Isolated ruminal epithelia from caudal blind sacs of dairy goats were incubated with butyrate and insulin-like growth factor-1（IGF-1） at different concentrations. Proportions of ruminal epithelium in different phase...Isolated ruminal epithelia from caudal blind sacs of dairy goats were incubated with butyrate and insulin-like growth factor-1（IGF-1） at different concentrations. Proportions of ruminal epithelium in different phases of the cell division cycle were determined by flow cytometric analysis. The proportion of epithelial cells in S phase and G2-M phase（PS＆G2-M） increased significantly（P〈0.01） whereas the proportion of epithelial cells in G0-G1 phase（PG0-G1） decreased after incubation with IGF-1. PS＆G2-M decreased whereas PG0-G1 increased markedly（P〈0.01） after incubation with sodium butyrate. PS＆G2-M incubated with IGF-1 and butyrate sodium together increased more than that incubated with IGF-1 alone; PG0-G1, however, decreased significantly（P〈0.01）. Our results indicate that IGF-1 enhances whereas sodium butyrate inhibits the proliferation of rumen epithelial cells. Furthermore, butyrate and IGF-1, together, have a synergic effect on the proliferation of rumen epithelium.展开更多
Grain-induced subacute ruminal acidosis(SARA)impairs rumen epithelial barrier function,but it is yet to be determined if SARA can cause persistent damage to the morphology and function of the rumen epithelial barrier....Grain-induced subacute ruminal acidosis(SARA)impairs rumen epithelial barrier function,but it is yet to be determined if SARA can cause persistent damage to the morphology and function of the rumen epithelial barrier.The objective of the present study was to investigate if SARA has persistent effects on the morphological structure and permeability of ruminal epithelium and the expression of the genes involved in epithelial barrier function using a lactating goat model.Twelve mid-lactating Saanen goats with rumen cannulas were randomly assigned to 1 of 2 groups:control group(Ctrl,n=4)fed a basal diet with a non-fiber carbohydrate(NFC)to neutral detergent fiber(NDF)ratio of 1.40,and SARA group(SARA,n=8)fed the same basal diet but with increasing NFC to NDF ratio from 1.4 to 1.79,2.31,and 3.23 overtime to induce SARA.At the end of the SARA challenge(post-SARA),4 goats were randomly selected from the SARA group and fed only hay mixture ad libitum for another 4 weeks to allow for restitution(post-SARA).Ruminal pH was continuously recorded to monitor the severity of SARA.Samples of the ventral ruminal epithelium were collected after slaughter to examine the structural and functional changes of the ruminal epithelium using transmission electron microscopy(TEM),Ussing chambers,qRT-PCR,and Western bolt analyses.Compared with the Ctrl group,ruminal papilla length,width,surface area and thickness of stratum corneum increased(P<0.05),while stratum spinosum and basale thickness,and total depth of the epithelium decreased(P<0.05)in the SARA group.These changes diminished or tended to return to the levels of the Ctrl group in the post-SARA group(P>0.05).The SARA challenge also decreased cellular junction and widened the intercellular space between epithelial cells.Rumen transepithelial short-circuit current(Isc),tissue conductance(Gt),and mucosa-to-serosa flux of paracellular horseradish peroxidase(HRP)all increased(P<0.05)both in the SARA and post-SARA groups,which indicates that SARA can induce a sustained increase in epithelial permeability and barrier dysfunction.Moreover,the mRNA and protein expressions of CLDN1,OCLN and ZO-1 were down-regulated(P<0.01)in both the SARA and post-SARA groups.The results of this study showed that SARA could result in sustained epithelial barrier dysfunction,at both structural and functional levels,which is associated with decreased expression of rumen epithelial tight junction proteins,and the restitution of rumen epithelial barrier function is slower than that of its morphology.展开更多
为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid ...为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid Air Energy Storage,LAES),提出了一种电热气冷IES低碳经济优化策略。首先,构建含变掺氧富氧燃烧燃气机组、利用LNG冷能的LAES、电转气(Power To Gas,P2G)设备、中央空调和溴化锂制冷机的IES架构,并建立各设备的数学模型;其次,引入阶梯式碳交易机制,建立了以系统运行成本最小为目标的电热气冷IES低碳经济调度模型;最后,采用MATLAB调用GUROBI求解器对多个场景进行求解,验证了文中提出的低碳经济优化调度策略可以提高系统的风电消纳、有效降低系统运行成本,实现碳减排。展开更多
文摘Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcera-tive colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inex-pensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d fol-lowed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentra-tion followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.
基金supported by the National Natural Science Foundation of China(30960252)the China Agriculture Research System(CARS-37)
文摘Isolated ruminal epithelia from caudal blind sacs of dairy goats were incubated with butyrate and insulin-like growth factor-1（IGF-1） at different concentrations. Proportions of ruminal epithelium in different phases of the cell division cycle were determined by flow cytometric analysis. The proportion of epithelial cells in S phase and G2-M phase（PS＆G2-M） increased significantly（P〈0.01） whereas the proportion of epithelial cells in G0-G1 phase（PG0-G1） decreased after incubation with IGF-1. PS＆G2-M decreased whereas PG0-G1 increased markedly（P〈0.01） after incubation with sodium butyrate. PS＆G2-M incubated with IGF-1 and butyrate sodium together increased more than that incubated with IGF-1 alone; PG0-G1, however, decreased significantly（P〈0.01）. Our results indicate that IGF-1 enhances whereas sodium butyrate inhibits the proliferation of rumen epithelial cells. Furthermore, butyrate and IGF-1, together, have a synergic effect on the proliferation of rumen epithelium.
基金supported by the National Natural ScienceFoundation of China(31472124)the Natural Science Foundation of Inner Mongolia,China(2019MS03031)+2 种基金the earmarked fund for China Agriculture Research System(CARS-36)the Innovation Fund of Inner Mongolia Agricultural and Animal Husbandry,China(2021CXJJM02)a China Scholarship Council(Beijing)fellowship to Hu Honglian for training at the Ohio State University,USA(201909150001)。
文摘Grain-induced subacute ruminal acidosis(SARA)impairs rumen epithelial barrier function,but it is yet to be determined if SARA can cause persistent damage to the morphology and function of the rumen epithelial barrier.The objective of the present study was to investigate if SARA has persistent effects on the morphological structure and permeability of ruminal epithelium and the expression of the genes involved in epithelial barrier function using a lactating goat model.Twelve mid-lactating Saanen goats with rumen cannulas were randomly assigned to 1 of 2 groups:control group(Ctrl,n=4)fed a basal diet with a non-fiber carbohydrate(NFC)to neutral detergent fiber(NDF)ratio of 1.40,and SARA group(SARA,n=8)fed the same basal diet but with increasing NFC to NDF ratio from 1.4 to 1.79,2.31,and 3.23 overtime to induce SARA.At the end of the SARA challenge(post-SARA),4 goats were randomly selected from the SARA group and fed only hay mixture ad libitum for another 4 weeks to allow for restitution(post-SARA).Ruminal pH was continuously recorded to monitor the severity of SARA.Samples of the ventral ruminal epithelium were collected after slaughter to examine the structural and functional changes of the ruminal epithelium using transmission electron microscopy(TEM),Ussing chambers,qRT-PCR,and Western bolt analyses.Compared with the Ctrl group,ruminal papilla length,width,surface area and thickness of stratum corneum increased(P<0.05),while stratum spinosum and basale thickness,and total depth of the epithelium decreased(P<0.05)in the SARA group.These changes diminished or tended to return to the levels of the Ctrl group in the post-SARA group(P>0.05).The SARA challenge also decreased cellular junction and widened the intercellular space between epithelial cells.Rumen transepithelial short-circuit current(Isc),tissue conductance(Gt),and mucosa-to-serosa flux of paracellular horseradish peroxidase(HRP)all increased(P<0.05)both in the SARA and post-SARA groups,which indicates that SARA can induce a sustained increase in epithelial permeability and barrier dysfunction.Moreover,the mRNA and protein expressions of CLDN1,OCLN and ZO-1 were down-regulated(P<0.01)in both the SARA and post-SARA groups.The results of this study showed that SARA could result in sustained epithelial barrier dysfunction,at both structural and functional levels,which is associated with decreased expression of rumen epithelial tight junction proteins,and the restitution of rumen epithelial barrier function is slower than that of its morphology.
文摘为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid Air Energy Storage,LAES),提出了一种电热气冷IES低碳经济优化策略。首先,构建含变掺氧富氧燃烧燃气机组、利用LNG冷能的LAES、电转气(Power To Gas,P2G)设备、中央空调和溴化锂制冷机的IES架构,并建立各设备的数学模型;其次,引入阶梯式碳交易机制,建立了以系统运行成本最小为目标的电热气冷IES低碳经济调度模型;最后,采用MATLAB调用GUROBI求解器对多个场景进行求解,验证了文中提出的低碳经济优化调度策略可以提高系统的风电消纳、有效降低系统运行成本,实现碳减排。
