Objective To investigate the mechanism of chaos during ventricular fibrillation(VF)after acute myocardial infarction(AMI)and observe the property of nonlinear dynamics of VF in order to provide clinical doctors with theory evidences to prevent VF after AMI.Methods From Jun.2003 to Dec.2005,we made the acute myocardial infacrtion model and induced VF of canine in vivo by using rapid pacing,and recorded the cardiac electrophysiological parameters by using 64-trains multi-polar epicardial-mapping electrocardiogram system to observe the change of the cycle length(CL)of ventricular arrhythmia in the Second Affiliated Hospital of China Medical Univercity.Results The pacing interval of VF in acute ischemia myocardium had been significantly increased; the cycle length(CL)showed the spatiotemporal complexity,such as period doubling bifurcation and quasiperiodicity and its Poincar'e plots formed a ring-like structure meaning nonlinear dynamics property during VF.Conclusion The liminal value of VF has been significantly increased during acute myocardial infarction.VF is induced by system come-into period doubling bifurcation,quasiperiodicity and chaos.

Objective To evaluate the methods and effects of modified surgical treatment for Amold-Chiari Ⅰ malformation complicated with syringomyelia.Methods Twelve patients with ArnoldChiari Ⅰ malformation complicated with syringomyelia,underwent a modified surgical treatment,effects were observed.Results During the first follow-up,sensation and motion function were significantly improved in 10 cases,unchanged in 2 cases.During the second follow-up,2 cases previously unchanged were improved,while the other were with no change.During the first follow-up,lesion showed on MRI disappeared in 5 cases,reduced in 4 cases,no significant change in 3 cases,no case extend,3 cases with hydrocephalus ventricle was significantly reduced.The second follow-up,MRI showed that there was no change compared with the first follow-up.Conclusion The remove of the pia mater of tonsillar hernia + reconstruction the cisterna magna have good effect on surgical therapies for Arnold-Chiari I malformation complicated with syringomyelia.

Objective To develop a new severe but sublethal acute pancreatitis mice model. Methods The animals were divided into two groups: the bile acid injection group and the control group. In the bile acid injection group, acute necrotizing pancreatitis was induced by intraductal administration of 0.1 ml of 1.0 % bile acid under 30 cm H 2O pressure, while the controls underwent the sham operation. The structural and functional features of the pancreas were examined at 24 hours after surgery. Results Pancreatic edema, bleeding, acinar cell necrosis and inflammation accompanied with increased serum amylase and MPO were found in the bile acid injection animals. Conclusions The sublethal acute pancreatitis mice model is ideal for pathogenetic and therapeutic study of acute necrotizing pancreatitis.

AIM: To explore the effects of glucocorticoids on fracture healing in a rat model of tibial fracture. METHODS: Sixty three months old female SD rats were divided into control and glucocorticoid-treated group. A glucocorticoid-induced osteoporosis model was established by intramuscular injection of prednisolone acetate (5 mg·kg~(-1)·d~(-1) for 3 weeks), in which the tibial was osteotomized by a wire saw as fracture healing model and internal fixed with a Kirschner pin. The rats were scarified at different time points after operation. The callus formation was monitored over a period of 6 weeks by histological method, bone mineral density (BMD) detection and biomechanical examination. Western blotting was used to measure the expression of type II collagen. RESULTS: A glucocorticoid-induced osteoporosis model was successfully established and conformed by BMD measurement. The formation of primary callus was observed in both groups 3 days after fracture. At 2 weeks after injury, the glucocorticoid-treated group had a lower BMD and less cartilage matrix as compared to control group. An increase in bone callus and chondrogenesis was observed at 4 to 6 weeks after fracture in glucocorticoid-treated group as compared to control group. The expression of type II collagen was delayed in glucocorticoid-treated group. Biomechanical measurement showed that the actual maximum load was increased by 35.8% in control group as compared to glucocorticoid-treated group at 6th week. CONCLUSION: These results indicate that chondrogenesis and transformation from cartilage callus to bony callus are delayed by glucocorticoids. The retardation of collagen Ⅱ production may be the reason for the inhibition of fracture healing.

Objective To study the protective effect and mechanism of safflower solution on warm ischemia reperfusion injury(IRI) of liver in rats.Methods Male Sprague-Dawley rats were randomly divided as 4 groups: Group S(sham group);group I/R(IRI group);group IPC(ischemic preconditioning group);group SPC(safflower solution preconditioning group).The rats were sacrificed at 24 h after reperfusion,serum levels of ALT and AST were measured and HE staining of liver tissues were made to detect rat liver histological changes and grade liver IRI(Suzuki score);apoptosis were monitored by TUNEL;TNF-?,MIP-2 and ICAM-1 mRNA of liver were measured by RT-PCR;NF-?B gene products of liver were detected by Western blotting.The mean value of all the assay tests was compared.Results After 24 h reperfusion,compared with group I/R,the liver function(ALT and AST) in group SPC and group IPC was significantly improved(P

Objective To investigate the autophagy capacity in clear cell renal cell carcinoma tissue compared with adjacent normal tissue.Methods Sixty-nine pairs of samples from human clear cell renal cell carcinoma tissues and relatively healthy renal tissues adjacent to the tumor were collected during surgical resection.The expressions of proteins that were participating in the regulation and execution of autophagy were detected by immunohistochemisty.Electron-microscopy was also carried out for the morphometrical analysis.Results The protein expression of p-mTOR (P =0.004),P62 (P =0.000) and ULK1 (P =0.000) were up-regulated in the carcinoma tissue,while the expression of Beclin1 (P=0.000),LC3 (P =0.000) and ATG7 (P =0.000) were down-regulated,and the expression of ATG5 (P =0.349) had no signif-icant difference compared with adjacent normal tissue.Morphometrical analysis showed that the basal autophagic activity (measured by the presence of autophagy vacuole compartment) was remarkably down-regulated in carcinoma tissue,compared with adjacent normal tissue.The expression level of mTOR was correlated with P62,LC3 and ATG7,but results showed no correlation between mTOR and Beclin 1.Conclusion Our studies show a relatively reduced autophagy capacity in clear cell renal cell carcinoma,which is regulated by multiple autophagy-related proteins such as mTOR,Beclin 1 and LC3.

Objective To study the high risk factors of anastomotic leakage after colon cancer surgery ,so as to provide evidence for the prevention of anastomotic leakage. Methods Fifty-three patients with anastomotic leakage after colon cancer surgery of 916 cases were selected as research objects,then the correlation between systemic factors,local factors and occurrence of anastomotic leakage was analyzed and studied. Results The correlation between age, ASA grade, serum hemoglobin, red blood cell, total protein, fasting blood glucose of systemic factors except for sex and occurrence of anastomotic leakage was obvious (P< 0.05). There was correlation between the methods of anastomosis, anastomotic tension, setting position of drainage tube, intestinal obstruction, abdominal infection and degree of tumor differentiation except for with or without chemotherapy and radiotherapy and occurrence of anastomotic leakage(P < 0.05). Conclusion The high risk factors of anastomotic leakage after colon cancer surgery are multiple,and well various work should be done during perioperative period.

Objective To establish the co-culture model in vitro and induce bone marrow mesenchymal stem cells (MSCs) to differentiate into lung alveolar epithelial cells. Methods Each group had 6 samples, control group was MSCs alone; Group A was the MSCs cultured with the cells from normal lung; and Group B was the MSCs with the cells from injuried lung. Each group was cultured for 8 days and the two markers of lung alveolar epithelial cells including AQP5 and SP-C were tested by laser confocal microscopy and RT-PCR. Results Only AQP5 was detected in the control group and Group A, both AQP5 and SP-C were detected in Group B, the AQP5 mRNA expression in Group B was significantly increased compared with that in the control group(P<0.01). The AQP5 mRNA expression in Group B was also significantly increased compared with that in Group A (P<0.01). But there was no significant difference in AQP5 mRNA expression between Group A and control group. Conclusion We have successfully established the co-culture model in vitro to induce bone marrow mesenchymal stem cells to differentiate into lung epithelial cells.

0.05). ConclusionsConventional radiotherapy plus three dimensional conformal radiotherapy combined with chemotherapy may significantly improve the survival rate and reduce the distant metastasis rate of locally advanced or recurrent rectal cancer.

Objective To evaluate the effect of pressure load of avascular necrosis of the femoral head(ANFH) by percutaneous injection of polymethylmethacrylate(PMMA).Methods Models of ANFH were established in 20 adult white rabbits with 40 femoral heads which were induced by injection of hydrochloride(HCL) and hormone.DR was performed to observe the bony density of femoral head in all rabbits,the cystic degeneration and collapse of femoral head were detected in 21 femoral heads,then DSA was done to observe the blood supply and they were divided into three groups at random,group A in 5 was examined by pathology,group B in 8 was injected with PMMA and group C was as control.The test of pressure loading was performed in group B and C.Results Of 21 femoral heads with cystic degeneration and collaps,8 were in the HCL-induced group and 13 were in the hormone-induced group.DSA showed that the blood supply was decreased,and the arteria were decreased in diameter.After the percutaneous injection of PMMA,all of 8 rabbits in experimental group were successful.The distinction between the means of two samples was significant in loading test(P