AIM： To investigate the effects of chitosan nanoparticles on proliferation of human gastric carcinoma cell line MGC803 in vitro and the possible mechanisms involved. METHODS： Chitosan nanoparticles were characterize...AIM： To investigate the effects of chitosan nanoparticles on proliferation of human gastric carcinoma cell line MGC803 in vitro and the possible mechanisms involved. METHODS： Chitosan nanoparticles were characterized by particle size, zeta potential, and morphology. After treatment with various concentrations of chitosan nanoparticles （25, 50, 75, 100 μg/mL） at various time intervals, cell proliferation, ultrastructural changes, DNA fragmentation, mitochondrial membrane potential （MMP）, cell cycle phase distribution and apoptotic peaks of MGC803 cells were analyzed by MTT assay, electron microscopy, DNA agarose gel electrophoresis, and flow cytometry. RESULTS： Chitosan nanoparticles exhibited a small particle size as 65 nm and a high surface charge as 52 mV. Chitosan nanoparticles markedly inhibited cell proliferation of MGC803 cells with an ICso value of 5.3 μg/mL 48 h after treatment. After treatment with chitosan nanoparticles, the typical necrotic cell morphology was observed by electron microscopy, a typical DNA degradation associated with necrosis was determined by DNA agarose electrophoresis. Flow cytometry showed the loss of MMP and occurrence of apoptosis in chitosan nanoparticles-treated cells. CONCLUSION： Chitosan nanoparticles effectively inhibit the proliferation of human gastric carcinoma cell line MGC803 in vitro through multiple mechanisms, and may be a beneficial agent against human carcinoma.展开更多
Objective： To explore the protective effects of two types of ischemic postconditioning （IP） on intestinal mucosa barrier in rabbits with crush injury of the hind limb. Methods： This study was conducted between Au...Objective： To explore the protective effects of two types of ischemic postconditioning （IP） on intestinal mucosa barrier in rabbits with crush injury of the hind limb. Methods： This study was conducted between August and December 2008 in the Department of Trauma Surgery, Daping Hospital, Third Military Medical University, Chongqing, China. The model of crush injury to the hind limb of rabbits was firstly developed by a 25 kg object with the right hind limbs fixed by wooden splints, and then two types of IP were established, including occluding/opening the common iliac artery and vein alternatively （traditional IP, IP A） and binding/loosening the proximum of the injured hind limb altematively （modified IP, IP B）. Thirty-six male New Zealand white rabbits were randomly divided into three groups： IP A group, IP B group and control group, with 12 rabbits in each group. The serum levels of diamine oxidase （DAO） and intestinal fatty acid-binding protein （I-FABP） were detected at 2, 6, 12 and 24 hours after injury. Pathologi- cal changes of ileum were examined at 24 hours after injury. Results： The serum levels of I-FABP at 2, 6, 12 and 24 hours after injury in both IPA and IP B groups had a significant decrease, compared with control group. DAO levels also showed the same change trend at 2 and 6 hours after injury, but showed no significant difference between two IP groups. No difference in pathological changes of ileum was found among the three groups. Conclusions： IP can protect intestinal mucosa barrier function on the model of hind limb crush injury in rabbits. Meanwhile the modified IP B shows the same protection as the traditional IP A, and is worth applying in clinic.展开更多
文摘AIM： To investigate the effects of chitosan nanoparticles on proliferation of human gastric carcinoma cell line MGC803 in vitro and the possible mechanisms involved. METHODS： Chitosan nanoparticles were characterized by particle size, zeta potential, and morphology. After treatment with various concentrations of chitosan nanoparticles （25, 50, 75, 100 μg/mL） at various time intervals, cell proliferation, ultrastructural changes, DNA fragmentation, mitochondrial membrane potential （MMP）, cell cycle phase distribution and apoptotic peaks of MGC803 cells were analyzed by MTT assay, electron microscopy, DNA agarose gel electrophoresis, and flow cytometry. RESULTS： Chitosan nanoparticles exhibited a small particle size as 65 nm and a high surface charge as 52 mV. Chitosan nanoparticles markedly inhibited cell proliferation of MGC803 cells with an ICso value of 5.3 μg/mL 48 h after treatment. After treatment with chitosan nanoparticles, the typical necrotic cell morphology was observed by electron microscopy, a typical DNA degradation associated with necrosis was determined by DNA agarose electrophoresis. Flow cytometry showed the loss of MMP and occurrence of apoptosis in chitosan nanoparticles-treated cells. CONCLUSION： Chitosan nanoparticles effectively inhibit the proliferation of human gastric carcinoma cell line MGC803 in vitro through multiple mechanisms, and may be a beneficial agent against human carcinoma.
文摘Objective： To explore the protective effects of two types of ischemic postconditioning （IP） on intestinal mucosa barrier in rabbits with crush injury of the hind limb. Methods： This study was conducted between August and December 2008 in the Department of Trauma Surgery, Daping Hospital, Third Military Medical University, Chongqing, China. The model of crush injury to the hind limb of rabbits was firstly developed by a 25 kg object with the right hind limbs fixed by wooden splints, and then two types of IP were established, including occluding/opening the common iliac artery and vein alternatively （traditional IP, IP A） and binding/loosening the proximum of the injured hind limb altematively （modified IP, IP B）. Thirty-six male New Zealand white rabbits were randomly divided into three groups： IP A group, IP B group and control group, with 12 rabbits in each group. The serum levels of diamine oxidase （DAO） and intestinal fatty acid-binding protein （I-FABP） were detected at 2, 6, 12 and 24 hours after injury. Pathologi- cal changes of ileum were examined at 24 hours after injury. Results： The serum levels of I-FABP at 2, 6, 12 and 24 hours after injury in both IPA and IP B groups had a significant decrease, compared with control group. DAO levels also showed the same change trend at 2 and 6 hours after injury, but showed no significant difference between two IP groups. No difference in pathological changes of ileum was found among the three groups. Conclusions： IP can protect intestinal mucosa barrier function on the model of hind limb crush injury in rabbits. Meanwhile the modified IP B shows the same protection as the traditional IP A, and is worth applying in clinic.
