Objective： To set up a swine model of severe acute pancreatitis（SAP） and to observe its relationship with the gut-originated bacteria/endotoxin translocation. Methods： Forty pigs weighing 17-22 kg were randomly di...Objective： To set up a swine model of severe acute pancreatitis（SAP） and to observe its relationship with the gut-originated bacteria/endotoxin translocation. Methods： Forty pigs weighing 17-22 kg were randomly diyided into SAP group （n=34） and sham-SAP group （n=6）. By injecting 1 ml/kg of combined solution of 5% sodium taurocholate and 8 000-10 000 benzoyl arginine ethyl ester（BAEE） units trypsin per milliliter into pancreas via pancreatic duct, SAP was induced under anesthesia. Endotoxin samples from vena cava were determined by chromogenic limulus amebocyte lysate （LAL） technique. Both portal and central vena blood samples were collected before and 72 h after the induction of SAP and cultured for both aerobic and anaerobic bacterial growth. Animals were sacrificed at the end of experiments by injecting 20 ml of 10% KCl intravenously and tissue specimens of mesenteriolum and mesocolon lymph nodes, lung, pulmonary portal lymph nods and pancreas were taken immediately after animal death, and homogenized for bacteriological studies. Results： Systemic plasma endotoxin levels increased rapidly 6 h post induction of SAP（PIS） with a peak at 48 h PIS （P〈0.01）. The magnitude of bacterial translocation in both portal and systemic blood and remote systemic organs as well were recovered PIS. Conclusion： （1） A swine model of SAP was established; （2）The early endotoxemia PIS seamed probable originated from gut endotoxin translocation; （3）The magnitude of bacterial translocation in both portal and systemic blood and the remote systemic organs as well were recovered at 72h PIS.展开更多
The main reason for the death of the patient with acute hemorrhage necrosis pancreatitis (AHNP) is pancreatic infection and multi-organ failure caused by endotoxemia and intestinal bacterial translocation[1-7]. Howeve...The main reason for the death of the patient with acute hemorrhage necrosis pancreatitis (AHNP) is pancreatic infection and multi-organ failure caused by endotoxemia and intestinal bacterial translocation[1-7]. However, the pathogenesis of endotoxemia and intestinal bacterial translocation remains a question[8-10]; moreover, no effective method of prevention and cure for it has been found till now[11 -15] In the present study, we infused low dose dopamine and low molecular weight dextran through the catheters to abdominal aorta and portal vein, and observed its influence on the endotoxin concentration in plasma and the rate of translocation of intestinal bacteria in AHNP rats.展开更多
Extrahepatic biliary obstruction promotes intestinal translocation of bacteria and endotoxin and this process is an important cause of morbidity and mortality in patients with jaundice. This study was undertaken to in...Extrahepatic biliary obstruction promotes intestinal translocation of bacteria and endotoxin and this process is an important cause of morbidity and mortality in patients with jaundice. This study was undertaken to investigate the effect and mechanism of recombinant human growth hormone (rhGH) and to alleviate intestinal translocation of bacteria and endotoxin in murine obstructive jaundice. METHODS:A group of 42 Wistar rats were divided into 3 groups:sham operation (SO), bile duct ligation (BDL), and BDL and rhGH treatment (rhGH). By the end of the experiment,on day 7, the animals were killed, and their liver function and serum endotoxin were measured, bacterial cultures of the liver, kidney and mesenchymal lymph were made. Terminal ileum mucosa was observed under an electron microscope. RESULTS:Liver function was improved more significantly in the rhGH group than in the BDL group. The value of endotoxin in the rhGH group was 0.38±0.03 EU/ml, significantly lower than that in the BDL group (0.65±0.04 EU/ml, P【0.01), and similar to that in the SO group (0.30±0.02 EU/ml, P】0.05). The rate of bacteria translocation in the liver, kidney and mesenteric lymph was much higher in the BDL group than in other two groups. The rate of bacteria translocation in mesenteric lymph was 64.29%,significantly higher than that in the SO group and the rhGH group (P【0.05). There was no significant difference in bacteria translocation rate between the SO group and the rhGH group (P】0.05). Under an electron microscope , ileum mucosa epithelial cells in the BDL group were necrotic, and organelle were markedly metamorphic. In the rhGH group, ultrastructural changes were less evident or similar to those in the SO group. CONCLUSION:rhGH has significant protective effects on intestinal mucosa barrier in obstructive jaundice, and reduces intestinal translocation of bacteria and endotoxin.展开更多
AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobari...AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.展开更多
Objective To investigate the effects of lactulose on intestinal bacterial overgrowth (IBO), bacterial translocation (BT), intestinal transit and permeability in cirrhotic rats. Methods BT in all animals was assessed...Objective To investigate the effects of lactulose on intestinal bacterial overgrowth (IBO), bacterial translocation (BT), intestinal transit and permeability in cirrhotic rats. Methods BT in all animals was assessed by bacterial culture of mesenteric lymph node (MLN), liver and spleen, and IBO was assessed by a jejunal bacterial count of the specific organism. Intestinal permeability was determined by the 24-hour urinary 99mTc-diethylenetriamine pentaacetatic acid ( 99mTc-DTPA) excretion, and intestinal transit was determined by measuring the distribution of 51Cr in the intestine. Results BT and IBO were found in 48% and 80% of the cirrhotic rats, respectively, while not in the control rats. Cirrhotic rats with IBO had significantly higher levels of intestinal endotoxin higher rates of bacterial translocation, shorter intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT were closely associated with IBO and injury of the intestinal barrier. Compared with the placebo group, lactulose-treated rats had lower rates of BT and IBO, which were closely associated with increased intestinal transit and improved intestinal permeability by lactulose. Conclusions Our study indicate that endotoxin and bacterial translocation in cirrhotic rats may attribute to IBO and increased intestinal permeability. Lactulose that accelerates intestinal transit and improves intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.展开更多
Alcohol is a major cause of chronic pancreatitis.About5%of alcoholics will ever suffer from pancreatitis,suggesting that additional co-factors are required to trigger an overt disease.Experimental work has implicated ...Alcohol is a major cause of chronic pancreatitis.About5%of alcoholics will ever suffer from pancreatitis,suggesting that additional co-factors are required to trigger an overt disease.Experimental work has implicated lipopolysaccharide,from gut-derived bacteria,as a potential co-factor of alcoholic pancreatitis.This review discusses the effects of alcohol on the gut flora,the gut barrier,the liver-and the pancreas and proposes potential interventional strategies.A better understanding of the interaction between the gut,the liver and the pancreas may provide valuable insight into the pathophysiology of alcoholic pancreatitis.展开更多
Colorectal cancer （CRC） is a multistage disease resulting from complex factors, including genetic mutations, epigenetic changes, chronic inflammation, diet, and lifestyle. Recent accumulating evidence suggests that ...Colorectal cancer （CRC） is a multistage disease resulting from complex factors, including genetic mutations, epigenetic changes, chronic inflammation, diet, and lifestyle. Recent accumulating evidence suggests that the gut microbiota is a new and important player in the development of CRC. Imbalance of the gut microbiota, especially dysregulated gut bacteria, contributes to colon cancer through mechanisms of inflammation, host defense modulations, oxidative stress, and alterations in bacterial-derived metabolism. Gut commensal bacteria are anatomically defined as four populations： luminal commensal bacteria, mucus-resident bacteria, epithelium-resident bacteria, and lymphoid tissue-resident commensal bacteria. The bacterial flora that are harbored in the gastrointestinal （GI） tract vary both longitudinally and cross-sectionally by different anatomical localization. It is notable that the translocation of colonic commensal bacteria is closely related to CRC progression. CRC-associated bacteria can serve as a noninvasive and accurate biomarker for CRC diagnosis. In this review, we summarize recent findings on the oncogenic roles of gut bacteria with different anatomical localization in CRC progression.展开更多
文摘Objective： To set up a swine model of severe acute pancreatitis（SAP） and to observe its relationship with the gut-originated bacteria/endotoxin translocation. Methods： Forty pigs weighing 17-22 kg were randomly diyided into SAP group （n=34） and sham-SAP group （n=6）. By injecting 1 ml/kg of combined solution of 5% sodium taurocholate and 8 000-10 000 benzoyl arginine ethyl ester（BAEE） units trypsin per milliliter into pancreas via pancreatic duct, SAP was induced under anesthesia. Endotoxin samples from vena cava were determined by chromogenic limulus amebocyte lysate （LAL） technique. Both portal and central vena blood samples were collected before and 72 h after the induction of SAP and cultured for both aerobic and anaerobic bacterial growth. Animals were sacrificed at the end of experiments by injecting 20 ml of 10% KCl intravenously and tissue specimens of mesenteriolum and mesocolon lymph nodes, lung, pulmonary portal lymph nods and pancreas were taken immediately after animal death, and homogenized for bacteriological studies. Results： Systemic plasma endotoxin levels increased rapidly 6 h post induction of SAP（PIS） with a peak at 48 h PIS （P〈0.01）. The magnitude of bacterial translocation in both portal and systemic blood and remote systemic organs as well were recovered PIS. Conclusion： （1） A swine model of SAP was established; （2）The early endotoxemia PIS seamed probable originated from gut endotoxin translocation; （3）The magnitude of bacterial translocation in both portal and systemic blood and the remote systemic organs as well were recovered at 72h PIS.
基金the China Postdoctoral Sciences Foundation No C.P.S.F 1996.2~#
文摘The main reason for the death of the patient with acute hemorrhage necrosis pancreatitis (AHNP) is pancreatic infection and multi-organ failure caused by endotoxemia and intestinal bacterial translocation[1-7]. However, the pathogenesis of endotoxemia and intestinal bacterial translocation remains a question[8-10]; moreover, no effective method of prevention and cure for it has been found till now[11 -15] In the present study, we infused low dose dopamine and low molecular weight dextran through the catheters to abdominal aorta and portal vein, and observed its influence on the endotoxin concentration in plasma and the rate of translocation of intestinal bacteria in AHNP rats.
文摘Extrahepatic biliary obstruction promotes intestinal translocation of bacteria and endotoxin and this process is an important cause of morbidity and mortality in patients with jaundice. This study was undertaken to investigate the effect and mechanism of recombinant human growth hormone (rhGH) and to alleviate intestinal translocation of bacteria and endotoxin in murine obstructive jaundice. METHODS:A group of 42 Wistar rats were divided into 3 groups:sham operation (SO), bile duct ligation (BDL), and BDL and rhGH treatment (rhGH). By the end of the experiment,on day 7, the animals were killed, and their liver function and serum endotoxin were measured, bacterial cultures of the liver, kidney and mesenchymal lymph were made. Terminal ileum mucosa was observed under an electron microscope. RESULTS:Liver function was improved more significantly in the rhGH group than in the BDL group. The value of endotoxin in the rhGH group was 0.38±0.03 EU/ml, significantly lower than that in the BDL group (0.65±0.04 EU/ml, P【0.01), and similar to that in the SO group (0.30±0.02 EU/ml, P】0.05). The rate of bacteria translocation in the liver, kidney and mesenteric lymph was much higher in the BDL group than in other two groups. The rate of bacteria translocation in mesenteric lymph was 64.29%,significantly higher than that in the SO group and the rhGH group (P【0.05). There was no significant difference in bacteria translocation rate between the SO group and the rhGH group (P】0.05). Under an electron microscope , ileum mucosa epithelial cells in the BDL group were necrotic, and organelle were markedly metamorphic. In the rhGH group, ultrastructural changes were less evident or similar to those in the SO group. CONCLUSION:rhGH has significant protective effects on intestinal mucosa barrier in obstructive jaundice, and reduces intestinal translocation of bacteria and endotoxin.
基金Supported by Scientific and Technical Research Funds from Chinese PLA during the Eleventh Five-Year Plan Period,No. 2008G093National Natural Science Foundation of China,No. 30900715National Science and Technology Ministry,No. 2009BAI85B03
文摘AIM:To study whether over-starvation aggravates intestinal mucosal injury and promotes bacterial and endotoxin translocation in a high-altitude hypoxic environment.METHODS:Sprague-Dawley rats were exposed to hy-pobaric hypoxia at a simulated altitude of 7000 m for 72 h.Lanthanum nitrate was used as a tracer to detect intestinal injury.Epithelial apoptosis was observed with terminal deoxynucleotidyl transferase dUTP nick end labeling staining.Serum levels of diamino oxidase(DAO),malondialdehyde(MDA),glutamine(Gln),superoxide dismutase(SOD) and endotoxin were measured in intestinal mucosa.Bacterial translocation was detected in blood culture and intestinal homogenates.In addition,rats were given Gln intragastrically to observe its protective effect on intestinal injury.RESULTS:Apoptotic epithelial cells,exfoliated villi and inflammatory cells in intestine were increased with edema in the lamina propria accompanying effusion of red blood cells.Lanthanum particles were found in the intercellular space and intracellular compartment.Bacterial translocation to mesenteric lymph nodes(MLN) and spleen was evident.The serum endotoxin,DAO and MDA levels were significantly higher while the serum SOD,DAO and Gln levels were lower in intestine(P< 0.05).The bacterial translocation number was lower in the high altitude hypoxic group than in the high altitude starvation group(0.47±0.83 vs 2.38±1.45,P<0.05).The bacterial translocation was found in each organ,especially in MLN and spleen but not in peripheral blood.The bacterial and endotoxin translocations were both markedly improved in rats after treatment with Gln.CONCLUSION:High-altitude hypoxia and starvation cause severe intestinal mucosal injury and increase bacterial and endotoxin translocation,which can be treated with Gln.
基金hisstudywaspartiallysupportedbytheNationalNaturalScienceFundationofChina (No .30 0 70 340 )
文摘Objective To investigate the effects of lactulose on intestinal bacterial overgrowth (IBO), bacterial translocation (BT), intestinal transit and permeability in cirrhotic rats. Methods BT in all animals was assessed by bacterial culture of mesenteric lymph node (MLN), liver and spleen, and IBO was assessed by a jejunal bacterial count of the specific organism. Intestinal permeability was determined by the 24-hour urinary 99mTc-diethylenetriamine pentaacetatic acid ( 99mTc-DTPA) excretion, and intestinal transit was determined by measuring the distribution of 51Cr in the intestine. Results BT and IBO were found in 48% and 80% of the cirrhotic rats, respectively, while not in the control rats. Cirrhotic rats with IBO had significantly higher levels of intestinal endotoxin higher rates of bacterial translocation, shorter intestinal transit time and higher intestinal permeability than those without IBO. It was also found that BT were closely associated with IBO and injury of the intestinal barrier. Compared with the placebo group, lactulose-treated rats had lower rates of BT and IBO, which were closely associated with increased intestinal transit and improved intestinal permeability by lactulose. Conclusions Our study indicate that endotoxin and bacterial translocation in cirrhotic rats may attribute to IBO and increased intestinal permeability. Lactulose that accelerates intestinal transit and improves intestinal permeability might be helpful in preventing intestinal bacterial and endotoxin translocation.
文摘Alcohol is a major cause of chronic pancreatitis.About5%of alcoholics will ever suffer from pancreatitis,suggesting that additional co-factors are required to trigger an overt disease.Experimental work has implicated lipopolysaccharide,from gut-derived bacteria,as a potential co-factor of alcoholic pancreatitis.This review discusses the effects of alcohol on the gut flora,the gut barrier,the liver-and the pancreas and proposes potential interventional strategies.A better understanding of the interaction between the gut,the liver and the pancreas may provide valuable insight into the pathophysiology of alcoholic pancreatitis.
基金This project was supported by RGC-GRF Hong l（ong （766613, 14106145）, the National Basic Research Program of China （2013CB531401）, the National Natural Science Foundation of China （NSFC） （81201963, 81372600）, the Shenzhen Municipal Science and Technology R＆D fund （JCYJ20120619152326450）, and the Shenzhen Virtual University Park Support Scheme to CUHK Shenzhen Research Institute.
文摘Colorectal cancer （CRC） is a multistage disease resulting from complex factors, including genetic mutations, epigenetic changes, chronic inflammation, diet, and lifestyle. Recent accumulating evidence suggests that the gut microbiota is a new and important player in the development of CRC. Imbalance of the gut microbiota, especially dysregulated gut bacteria, contributes to colon cancer through mechanisms of inflammation, host defense modulations, oxidative stress, and alterations in bacterial-derived metabolism. Gut commensal bacteria are anatomically defined as four populations： luminal commensal bacteria, mucus-resident bacteria, epithelium-resident bacteria, and lymphoid tissue-resident commensal bacteria. The bacterial flora that are harbored in the gastrointestinal （GI） tract vary both longitudinally and cross-sectionally by different anatomical localization. It is notable that the translocation of colonic commensal bacteria is closely related to CRC progression. CRC-associated bacteria can serve as a noninvasive and accurate biomarker for CRC diagnosis. In this review, we summarize recent findings on the oncogenic roles of gut bacteria with different anatomical localization in CRC progression.
