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OBJECTIVE:To investigate the long-term toxicity of repeated intramuscular injection of Escherichia coli O157∶H7 polysaccharide-conjugated vaccine(O157) in rats so as to provide safety evidence for clinical trials.METHODS:A total of 48 SD rats were randomly assigned to receive either 0.5 mL vaccine(containing 25 ?g polysaccharides) (immunization group,n=24) or phosphate buffered solution (PBS,control group,n=24) with the same volume for 3 times at a dose interval of two weeks.Sacrifice of 6 rats in each group were scheduled at 2 weeks after first immunization,and at 1,3,and 5 weeks after the third immunization,respectively for observation and determination of hematological and biochemical parameters,histopathology,specific antibody,myeloid tissue,the tissues in injection sites,etc.RESULTS:Compared with control group,immunization group showed no significant pathological change except the dynamic regular change of some hematological parameters induced by the immunization,and no immunologic system damage was observed.CONCLUSION:Repeated intramuscular injection with O157 vaccine in rats wouldn't cause overt toxicity and local irritation.
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OBJECTIVE:To study the mechanism of action of grape seed proanthocynidins extract(GSPE)in treating acetic acid-induced colitis gravis in rats.METHODS:Rats model with acetic acid-induced colitis was built,the animals were di-vided into normal control group,model group,positive control group and GSPE group(which were subdivided into low,medium and high dose subgroups by intragastric administration).On the8th day of administration of drugs,the changes of myeloperoxidase(MPO),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and malonaldehyde(MDA)in colonic tissue were detected,respectively.RESULTS:The model group had a significantly higher level of MPO content than did the normal control group(P
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AIM: To inverstigate the protective effects of procyanidin on myocardial ischemia reperfusion injury in rats. METHODS: Myocardial ischemia reperfusion injury models were established by the ligation of left desending coronary artery for 40 min and referfusion for 120 min in rats, and the influence of procyanidin on enzymes of myocardial, myocardial infarction size and lipid peroxide were observed. RESULTS: Procyanidin decreased myocardial creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) release significantly diminished myocardial infarction size, raised the activity of superoxide dismutase (SOD), reduced malondialdehyde (MDA) content in myocardial and serum in comparison with the control. CONCLUSION: Procyanidin has a protective effect on myocardial ischemia reperfusion injury. The action is related to the inhibition of the free radical and subsequent lipid peroxidation.
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AIM To study the effects of rh bFGF on healing quality of chronic gastric ulcer in rats. METHODS Ulcer model induced by acetic acid was established. Rats were treated with rh bFGF ig until ulcer healing and then continually treated for 10 days(30 total treatment days). The effects of rh bFGF on healing quality of chronic gastric ulcer was evaluated not only from gastric mucoal barrier tissue structure but also from gastric mucus barrier. RESULTS rh bFGF( 5 000 ～ 10 000 AU?kg -1 ) increased the thickness of regenerated gastric mucosa, lowed its abnormity degree and made its align state near to normal. rh bFGF( 2 500 ～ 10 000 AU?kg -1 ) increased collagen and capillary density in scar tissue, added mucus quantity, mucopolysaccharide layer's thickness and PGE 2 content on the surface of regenerated gastric mucosa. CONCLUSION rh bFGF has effects of promoting gastric mucosal barrier to mature, increasing the function of gastric mucus barrier and increasing the quality of ulcer healing.