In order to thoroughly understand the mechanism Of drought resistance in plants at DNA level, the DNA damage of two ecotypes of reeds (Phragmites communis T.) stressed by PEG 6000 was analyzed by means of fluorescence...In order to thoroughly understand the mechanism Of drought resistance in plants at DNA level, the DNA damage of two ecotypes of reeds (Phragmites communis T.) stressed by PEG 6000 was analyzed by means of fluorescence analysis of DNA unwinding (FADU). The results showed that the residual double strand DNA percentages (dsDNA%) in dune reed (DR) were significantly higher than those in swamp reed (SR) treated with either 20% or 30% PEG 6000. This meant that the DNA of DR was less damaged in comparison with SR. Similarly, DR resisted DNA damage more strongly than SR as reactive oxygen species (ROS) increased by adding ROS producers diethyldithio carbamate (DDC), H2O2 and Fe2+ of different concentrations. Meanwhile, treating PEG stressed SR with ROS scavengers such as dimethyl sulphoxide (DMSO) and ascorbic acid (Vc) resulted in the reduction of DNA damage, suggesting that ROS could cause DNA damage. In addition, the DNA repair for water-stressed reeds indicated that DR repaired DNA damage much faster and more completely. This might be the first indication that drought stress led to DNA damage in plants and that drought resistance of plants was closely related to DNA damage and repair.展开更多
Objective: To study the effects of platelet activation and endothelial cell injury on the patients with malignant tumor and their prognoses.Methods: Radioimmunity and ELISA methods were employed to detect the TXB2, GM...Objective: To study the effects of platelet activation and endothelial cell injury on the patients with malignant tumor and their prognoses.Methods: Radioimmunity and ELISA methods were employed to detect the TXB2, GMP-140, vWF, cGMP and FN in 78 cases of malignant tumor and 40 healthy control persons.Results: The levels of TXB2, MP-140 and cGMP were increased in intestinal cancer group, lung cancer group and hepatic cancer group, while FN decreased in intestinal cancer and lung cancer group. cGMP was positively related to TXB2, GMP-140, vWF in malignant tumor group. FN was decreased in the group complicated with infection and the group with metastasis, while the other indexes increased. GMP-140, vWF and cGMP was decreased after operation except for the increasing of FN.Conclusion: Activations of platelet and injury of endothelial cells developed in patients with malignant tumor, and both of them affected the metastasis and prognosis of malignant tumor. Key words platelet activation - epithelium injury - malignant tumor - metastasis This work was supported by grants from Guangdong Medical Science foundation (A2000633).展开更多
A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensi...A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.展开更多
Absolute light utilization efficiency across leaf section of Euonymus japonicus T. was calculated based on the measurements of photoacoustic technique (PA technique) and microscopic fiber optic probe. This new method ...Absolute light utilization efficiency across leaf section of Euonymus japonicus T. was calculated based on the measurements of photoacoustic technique (PA technique) and microscopic fiber optic probe. This new method was based on the principal of depth analysis by PA technique and the differential analysis of light gradients across leaf section by micro-optical probe technique. The depth analysis was shown by a sample of PA scan light absorption spectra. Results showed that the tissue layers between palisade tissue and spongy tissue used the smallest proportion of incident light energy for photochemical reactions (about 0.026% incident light energy of 660 nm light), while in tissue layer more close to the adaxial surface of leaf or the abaxial surface of leaf, the efficiency of utilization of light energy tended to be improved, e. g. 0.092% for tissue layers close to adaxial surface; 0.036% for tissue layers close to abaxial surface. The results that different leaf tissue layers utilized different proportion of incident light energy for photochemical reaction directly prove the hypothesis put forward by Han and Vogelmann.展开更多
A fitting process is used to measure the cavity loss and the quasi Fermi level separation for Fabry Pérot semiconductor lasers.From the amplified spontaneous emission (ASE) spectrum,the gain spectrum and sing...A fitting process is used to measure the cavity loss and the quasi Fermi level separation for Fabry Pérot semiconductor lasers.From the amplified spontaneous emission (ASE) spectrum,the gain spectrum and single pass ASE obtained by the Cassidy method are applied in the fitting process.For a 1550nm quantum well InGaAsP ridge waveguide laser,the cavity loss of about ～24cm -1 is obtained.展开更多
Objective. To study the characteristics and pathogenesis of gut barrier damage following multiple firearm injuries in a porcine model. Methods. Twenty four small pigs were divided into 4 groups: control group (n=6, gr...Objective. To study the characteristics and pathogenesis of gut barrier damage following multiple firearm injuries in a porcine model. Methods. Twenty four small pigs were divided into 4 groups: control group (n=6, group C), group H (n=6, gunshot induced tangential fracture of parietal bone), group L (n=6, gunshot induced comminuted fracture of bilateral femora) and group M (n=6, combined group H+L). Gastric intramucosal pH (pHi), plasma endotoxin levels in portal vein, and plasma D lactate levels were measured and blood samples were cultured at different intervals after trauma. The animals were sacrificed at 72 h following trauma and intestinal tissues were harvested for pathological examination and diamine oxidase (DAO) activity measurement. Results. In group M at 72 h, pHi was significantly lower than that of group H and L (P< 0.01), and plasma endotoxin level was significantly higher than that of group H (P< 0.01) and group L (P< 0.05). Simultaneously, in groupM, D lactate level was markedly higher than that of group H (P< 0.01), and incidence of positive blood culture was much higher than that of group H and L (P<0.05). Necrosis and exfoliation were revealed at ileum villus top in all traumagroups, especially in group M, in which ileum DAO activity declined most significantly as well. Conclusion. Multiple trauma is prone to cause gastrointestinal ischemia even without hemorrhagic shock. The damage of gut barrier in multiple trauma appears to be more severe than that in one site trauma, thereby promoting gut derived endotoxemia and bacterial translocation and contributing to the development of endogenous infection.SURGICAL TREATMENT OF MALIGNANTESOPHAGEAL TUMORS IN PUMC HOSPITAL Guo Huiqin,Li Zejian ,Zhang Fan1 ,Zhang Zhiyong,Xu Letian ,Li Weidong2,Wang Xiuqin2and Wu Min2Department of Thoracic Surgery, PUMC Hospital, CAMS &PUMC, Beijing 100730Key words malignant esophageal tumors; early diagnosis; FHIT geneTo study how to prolong the postoperative survival time of the patientswith malignant esophageal tumors. The clinical data of 1098 patients with malignant esophageal tumors from 1961 to 1992 were retrospectively analyzed. The deletion of fragile histamine triplet (FHIT) gene (a tumor suppressor gene) in 30 fresh esophageal samples obtained in 1996 was detected with PCR and RT PCR method. The resectability was raised gradually and the operative morbidity and mortality decreased year by year, but there was no significant improvement on the postoperative 5 year survival rate. Delayed diagnosis and irradical resection influenced the long term survival. The deletion of cDNA of FHIT gene was 64.2%in esophageal cancer and 20%in the resected margin of the cancer. We believe that high grade atypical hyperplasia in esophageal epithelium and deletion of FHIT gene in esophageal cancer and its resected margin are pathological and molecular markers for early diagnosis of esophageal cancer respectively, and the latter may be one of the molecular markers for the resection. Early diagnosis and treatment, radical resection, and postoperative nutritional support are very important for the improvement of the postoperative survival time of the patients.展开更多
AIM： To clarify the risk factors for bleeding after endoscopic mucosal resection （EMR）. METHODS： A total of 297 consecutive patients who underwent EMR were enrolled. Some of the patients had multiple lesions. Blee...AIM： To clarify the risk factors for bleeding after endoscopic mucosal resection （EMR）. METHODS： A total of 297 consecutive patients who underwent EMR were enrolled. Some of the patients had multiple lesions. Bleeding requiring endoscopic treatment was defined as bleeding after EMR. Odds ratios （OR） with 95% confidence intervals （CI）, calculated by logistic regression with multivariate adjustments for covariates, were the measures of association. RESULTS： Of the 297 patients, 57 （19.2%） patients with bleeding after EMR were confirmed. With multivariate adjustment, the cutting method of EMR, diameter, and endoscopic pattern of the tumor were associated with the risk of bleeding after EMR. The multivariate-adjusted OR for bleeding after EMR using endoscopic aspiration mucosectomy was 3.07 （95%CI, 1.59-5.92） compared with strip biopsy. The multiple-adjusted OR for bleeding after EMR for the highest quartile （16-50 mm） of tumor diameter was 5.63 （95%CI, 1.84-17.23） compared with that for the lowest （4-7 mm）. The multiple-adjusted OR for bleeding after EMR for depressed type of tumor was 4.21 （95%CI, 1.75-10.10） compared with elevated type. CONCLUSION： It is important to take tumor charactedstics （tumor size and endoscopic pattern） and cutting method of EMR into consideration in predicting bleeding after EMR.展开更多
Type I gastric cardnoid tumors result from hypergastrinemia in 1%-7% of patients with pernicious anemia. We diagnosed pernicious anemia in a 48-year-old female patient with complaint of fatigue for three months. She h...Type I gastric cardnoid tumors result from hypergastrinemia in 1%-7% of patients with pernicious anemia. We diagnosed pernicious anemia in a 48-year-old female patient with complaint of fatigue for three months. She had no gastrointestinal symptoms. Endoscopic examination ot the upper gastrointestinal tract revealed atrophic gastritis and a polypoid lesion in the corpus of 3-4 mm in size. Endoscopic polypectomy was performed. Histopathological examination of the specimen revealed positive chromogranin A and synaptophysin stainings compatible with the diagnosis of a carcinoid tumor. Serum gastrin level was increased, urinary 5-hydroxyindoleacetic acid was within the normal range. There was no other symptom, sign, or laboratory finding of a carcinoid syndrome in the patient. No metastasis was found with indium-ill octreotide scan, computed tomographies of abdomen and thorax. Type I gastric carcinoid tumors are only rarely solitary and patients with tumors 〈 1 cm in size may benefit from endoscopic polypectomy.展开更多
AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, act...AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-KB （NF-κB） and tumor necrosis factor-α （TNF-α） expression in the liver. METHODS： Female Sprague-Dawley rats were given fish oil （0.5 mL） along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase （ALT） activity and pathological analysis. Liver malondialdehyde （MDA）, nitric oxide contents, iNOS and eNOS activity were determined. NF-κB p65, iNOS, eNOS and TNF-α protein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction （RT-PCR）. RESULTS： Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration （6 wk） enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-κB p65, iNOS and TNF-α protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-KB, and TNF-α mRNA expression. CONCLUSION： iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-KB and TNF-α expression, eNOS activity is reduced, but its mRNA expression is not affected.展开更多
AIM: To study the changes of endogenous interleukin 18 (IL-18) levels and evaluate the role of IL-18 on lung injury following gut ischemia/reperfusion.METHODS: A superior mesenteric artery occlusion model was selected...AIM: To study the changes of endogenous interleukin 18 (IL-18) levels and evaluate the role of IL-18 on lung injury following gut ischemia/reperfusion.METHODS: A superior mesenteric artery occlusion model was selected for this research. The mice were randomly divided into four groups: Sham operation (sham), ischemia (0.5 h) followed by different times of reperfusion (I/R),and I/R pretreated with exogenous IL-18 (I/R+IL-18) or IL-18 neutralizing antibody (I/R+IL-18Ab) 15 min before ischemia. Serum IL-18 levels were detected by Western blot and ELISA, and the levels of IL-18 in lung tissue were evaluated by immunohistochemical staining. For the study of pulmonary inflammation, the lung myeloperoxidase (MPO) contents and morphological changes were evaluated.RESULTS: Gut ischemia/reperfusion induced rapid increase of serum IL-18 levels, peaked at 1 h after reperfusion and then declined. The levels of IL-18 in lung tissue were gradually enhanced as the progress of reperfusion.Compared with I/R group, exogenous administration of IL-18 (I/R+IL-18) further remarkably enhanced the pulmonary MPO activity and inflammatory cell infiltration,and in I/R+IL-18Ab group, the content of MPO were significantly reduced and lung inflammation was also decreased.CONCLUSION: Gut ischemia/reperfusion induces the increase of IL-18 expression, which may make IL-18 act as an important proinflammatory cytokine and contribute to gut ischemia/reperfusion-induced lung inflammation.展开更多
文摘In order to thoroughly understand the mechanism Of drought resistance in plants at DNA level, the DNA damage of two ecotypes of reeds (Phragmites communis T.) stressed by PEG 6000 was analyzed by means of fluorescence analysis of DNA unwinding (FADU). The results showed that the residual double strand DNA percentages (dsDNA%) in dune reed (DR) were significantly higher than those in swamp reed (SR) treated with either 20% or 30% PEG 6000. This meant that the DNA of DR was less damaged in comparison with SR. Similarly, DR resisted DNA damage more strongly than SR as reactive oxygen species (ROS) increased by adding ROS producers diethyldithio carbamate (DDC), H2O2 and Fe2+ of different concentrations. Meanwhile, treating PEG stressed SR with ROS scavengers such as dimethyl sulphoxide (DMSO) and ascorbic acid (Vc) resulted in the reduction of DNA damage, suggesting that ROS could cause DNA damage. In addition, the DNA repair for water-stressed reeds indicated that DR repaired DNA damage much faster and more completely. This might be the first indication that drought stress led to DNA damage in plants and that drought resistance of plants was closely related to DNA damage and repair.
基金This work was supported by grants from Guangdong Medical Science foundation(A2000633).
文摘Objective: To study the effects of platelet activation and endothelial cell injury on the patients with malignant tumor and their prognoses.Methods: Radioimmunity and ELISA methods were employed to detect the TXB2, GMP-140, vWF, cGMP and FN in 78 cases of malignant tumor and 40 healthy control persons.Results: The levels of TXB2, MP-140 and cGMP were increased in intestinal cancer group, lung cancer group and hepatic cancer group, while FN decreased in intestinal cancer and lung cancer group. cGMP was positively related to TXB2, GMP-140, vWF in malignant tumor group. FN was decreased in the group complicated with infection and the group with metastasis, while the other indexes increased. GMP-140, vWF and cGMP was decreased after operation except for the increasing of FN.Conclusion: Activations of platelet and injury of endothelial cells developed in patients with malignant tumor, and both of them affected the metastasis and prognosis of malignant tumor. Key words platelet activation - epithelium injury - malignant tumor - metastasis This work was supported by grants from Guangdong Medical Science foundation (A2000633).
文摘A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.
文摘Absolute light utilization efficiency across leaf section of Euonymus japonicus T. was calculated based on the measurements of photoacoustic technique (PA technique) and microscopic fiber optic probe. This new method was based on the principal of depth analysis by PA technique and the differential analysis of light gradients across leaf section by micro-optical probe technique. The depth analysis was shown by a sample of PA scan light absorption spectra. Results showed that the tissue layers between palisade tissue and spongy tissue used the smallest proportion of incident light energy for photochemical reactions (about 0.026% incident light energy of 660 nm light), while in tissue layer more close to the adaxial surface of leaf or the abaxial surface of leaf, the efficiency of utilization of light energy tended to be improved, e. g. 0.092% for tissue layers close to adaxial surface; 0.036% for tissue layers close to abaxial surface. The results that different leaf tissue layers utilized different proportion of incident light energy for photochemical reaction directly prove the hypothesis put forward by Han and Vogelmann.
文摘A fitting process is used to measure the cavity loss and the quasi Fermi level separation for Fabry Pérot semiconductor lasers.From the amplified spontaneous emission (ASE) spectrum,the gain spectrum and single pass ASE obtained by the Cassidy method are applied in the fitting process.For a 1550nm quantum well InGaAsP ridge waveguide laser,the cavity loss of about ～24cm -1 is obtained.
文摘Objective. To study the characteristics and pathogenesis of gut barrier damage following multiple firearm injuries in a porcine model. Methods. Twenty four small pigs were divided into 4 groups: control group (n=6, group C), group H (n=6, gunshot induced tangential fracture of parietal bone), group L (n=6, gunshot induced comminuted fracture of bilateral femora) and group M (n=6, combined group H+L). Gastric intramucosal pH (pHi), plasma endotoxin levels in portal vein, and plasma D lactate levels were measured and blood samples were cultured at different intervals after trauma. The animals were sacrificed at 72 h following trauma and intestinal tissues were harvested for pathological examination and diamine oxidase (DAO) activity measurement. Results. In group M at 72 h, pHi was significantly lower than that of group H and L (P< 0.01), and plasma endotoxin level was significantly higher than that of group H (P< 0.01) and group L (P< 0.05). Simultaneously, in groupM, D lactate level was markedly higher than that of group H (P< 0.01), and incidence of positive blood culture was much higher than that of group H and L (P<0.05). Necrosis and exfoliation were revealed at ileum villus top in all traumagroups, especially in group M, in which ileum DAO activity declined most significantly as well. Conclusion. Multiple trauma is prone to cause gastrointestinal ischemia even without hemorrhagic shock. The damage of gut barrier in multiple trauma appears to be more severe than that in one site trauma, thereby promoting gut derived endotoxemia and bacterial translocation and contributing to the development of endogenous infection.SURGICAL TREATMENT OF MALIGNANTESOPHAGEAL TUMORS IN PUMC HOSPITAL Guo Huiqin,Li Zejian ,Zhang Fan1 ,Zhang Zhiyong,Xu Letian ,Li Weidong2,Wang Xiuqin2and Wu Min2Department of Thoracic Surgery, PUMC Hospital, CAMS &PUMC, Beijing 100730Key words malignant esophageal tumors; early diagnosis; FHIT geneTo study how to prolong the postoperative survival time of the patientswith malignant esophageal tumors. The clinical data of 1098 patients with malignant esophageal tumors from 1961 to 1992 were retrospectively analyzed. The deletion of fragile histamine triplet (FHIT) gene (a tumor suppressor gene) in 30 fresh esophageal samples obtained in 1996 was detected with PCR and RT PCR method. The resectability was raised gradually and the operative morbidity and mortality decreased year by year, but there was no significant improvement on the postoperative 5 year survival rate. Delayed diagnosis and irradical resection influenced the long term survival. The deletion of cDNA of FHIT gene was 64.2%in esophageal cancer and 20%in the resected margin of the cancer. We believe that high grade atypical hyperplasia in esophageal epithelium and deletion of FHIT gene in esophageal cancer and its resected margin are pathological and molecular markers for early diagnosis of esophageal cancer respectively, and the latter may be one of the molecular markers for the resection. Early diagnosis and treatment, radical resection, and postoperative nutritional support are very important for the improvement of the postoperative survival time of the patients.
文摘AIM： To clarify the risk factors for bleeding after endoscopic mucosal resection （EMR）. METHODS： A total of 297 consecutive patients who underwent EMR were enrolled. Some of the patients had multiple lesions. Bleeding requiring endoscopic treatment was defined as bleeding after EMR. Odds ratios （OR） with 95% confidence intervals （CI）, calculated by logistic regression with multivariate adjustments for covariates, were the measures of association. RESULTS： Of the 297 patients, 57 （19.2%） patients with bleeding after EMR were confirmed. With multivariate adjustment, the cutting method of EMR, diameter, and endoscopic pattern of the tumor were associated with the risk of bleeding after EMR. The multivariate-adjusted OR for bleeding after EMR using endoscopic aspiration mucosectomy was 3.07 （95%CI, 1.59-5.92） compared with strip biopsy. The multiple-adjusted OR for bleeding after EMR for the highest quartile （16-50 mm） of tumor diameter was 5.63 （95%CI, 1.84-17.23） compared with that for the lowest （4-7 mm）. The multiple-adjusted OR for bleeding after EMR for depressed type of tumor was 4.21 （95%CI, 1.75-10.10） compared with elevated type. CONCLUSION： It is important to take tumor charactedstics （tumor size and endoscopic pattern） and cutting method of EMR into consideration in predicting bleeding after EMR.
文摘Type I gastric cardnoid tumors result from hypergastrinemia in 1%-7% of patients with pernicious anemia. We diagnosed pernicious anemia in a 48-year-old female patient with complaint of fatigue for three months. She had no gastrointestinal symptoms. Endoscopic examination ot the upper gastrointestinal tract revealed atrophic gastritis and a polypoid lesion in the corpus of 3-4 mm in size. Endoscopic polypectomy was performed. Histopathological examination of the specimen revealed positive chromogranin A and synaptophysin stainings compatible with the diagnosis of a carcinoid tumor. Serum gastrin level was increased, urinary 5-hydroxyindoleacetic acid was within the normal range. There was no other symptom, sign, or laboratory finding of a carcinoid syndrome in the patient. No metastasis was found with indium-ill octreotide scan, computed tomographies of abdomen and thorax. Type I gastric carcinoid tumors are only rarely solitary and patients with tumors 〈 1 cm in size may benefit from endoscopic polypectomy.
文摘AIM： To study the expression and activity of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） in rats with ethanol-induced liver injury and their relation with liver damage, activation of nuclear factor-KB （NF-κB） and tumor necrosis factor-α （TNF-α） expression in the liver. METHODS： Female Sprague-Dawley rats were given fish oil （0.5 mL） along with ethanol or isocaloric dextrose daily via gastrogavage for 4 or 6 wk. Liver injury was assessed using serum alanine aminotransferase （ALT） activity and pathological analysis. Liver malondialdehyde （MDA）, nitric oxide contents, iNOS and eNOS activity were determined. NF-κB p65, iNOS, eNOS and TNF-α protein or mRNA expression in the liver were detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction （RT-PCR）. RESULTS： Chronic ethanol gavage for 4 wk caused steatosis, inflammation and necrosis in the liver, and elevated serum ALT activity. Prolonged ethanol administration （6 wk） enhanced the liver damage. These responses were accompanied with increased lipid peroxidation, NO contents, iNOS activity and reduced eNOS activity. NF-κB p65, iNOS and TNF-α protein or mRNA expression were markedly induced after chronic ethanol gavage, whereas eNOS mRNA expression remained unchanged. The enhanced iNOS activity and expression were positively correlated with the liver damage, especially the necro-inflammation, activation of NF-KB, and TNF-α mRNA expression. CONCLUSION： iNOS expression and activity are induced in the liver after chronic ethanol exposure in rats, which are correlated with the liver damage, especially the necro-inflammation, activation of NF-KB and TNF-α expression, eNOS activity is reduced, but its mRNA expression is not affected.
基金Supported by the CAS Pilot Project of Knowledge Innovation Program, No. KSCX 2-3-04-03
文摘AIM: To study the changes of endogenous interleukin 18 (IL-18) levels and evaluate the role of IL-18 on lung injury following gut ischemia/reperfusion.METHODS: A superior mesenteric artery occlusion model was selected for this research. The mice were randomly divided into four groups: Sham operation (sham), ischemia (0.5 h) followed by different times of reperfusion (I/R),and I/R pretreated with exogenous IL-18 (I/R+IL-18) or IL-18 neutralizing antibody (I/R+IL-18Ab) 15 min before ischemia. Serum IL-18 levels were detected by Western blot and ELISA, and the levels of IL-18 in lung tissue were evaluated by immunohistochemical staining. For the study of pulmonary inflammation, the lung myeloperoxidase (MPO) contents and morphological changes were evaluated.RESULTS: Gut ischemia/reperfusion induced rapid increase of serum IL-18 levels, peaked at 1 h after reperfusion and then declined. The levels of IL-18 in lung tissue were gradually enhanced as the progress of reperfusion.Compared with I/R group, exogenous administration of IL-18 (I/R+IL-18) further remarkably enhanced the pulmonary MPO activity and inflammatory cell infiltration,and in I/R+IL-18Ab group, the content of MPO were significantly reduced and lung inflammation was also decreased.CONCLUSION: Gut ischemia/reperfusion induces the increase of IL-18 expression, which may make IL-18 act as an important proinflammatory cytokine and contribute to gut ischemia/reperfusion-induced lung inflammation.
