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 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.

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.

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 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.

ObjectiveTo investigate the surgical procedures of orthotopic small bowel transplantation (SBT) model in mice to study the function and rejection of SBT.MethodsWe established a mouse SBT allograft model as follows: the donor portal vein was anastomosed end by side with the recipient inferior vena cava; the donor superior mesenteric artery with aorta patch was anastomosed end by side with recipient abdominal aorta.After an appropriate length of the recipient's small bowel was removed,the donor's small bowel and the recipient's small bowel were end-to-end anastomosed discontinuously.The mice were fasted for 4 d after the operation,free access to water and subcutaneously injection of 2 mL of 5％ glucose saline twice daily.Operation success was regarded as survival for more than 5 d.There is no antibiotic and immunosuppressor.ResultsA total of 30 transplantations were done,the 5 d survival rate was 60％ ( 18/30),and 12 died within 5 d.Among the dead recipients,5 died of arterial anastomotic stenosis and anastomotic thrombosis,2 of hemorrhagic shock caused by anastomotic bleeding,and the other 5 of intra-abdominal infection caused by postoperative intestinal fistula.The donors' operative time was (40 ± 4.5 ) min,warm ischemia time was about 0.5 min,donor preparation time was about 3 min,and cold preservation time was (30 ±7.5) min.The recipients' operative time was (95 ±8.0) min,among which,the abdominal aorta and inferior vena cava clamping time was ( 38 ± 3.5 ) min,the venous anastomotic time was (10 ±2.0) min and the arterial anastomotic time was (15 ± 3.0) min.The mean intraoperative blood loss of the surviving recipient mice was about 0.2 mL.ConclusionHigh quality vascular anastomosis,and rehydration of donors and recipients are crucial factors for improving the success rate of SBT.

ObjectiveTo investigate the expression of T helper (Th) 17 cells and the related interleukin 17 (IL-17) in acute renal allograft rejection in mice and its significance.Methods We established a mouse renal allograft model,in which mice were randomly divided into a renal isograft group and an acute renal allograft rejection group.Three and 7 d after the transplantation,the serum interferon (IFN)-γand IL-17 levels in the mice were determined by enzyme-linked immunosorbent assay,the percentage of Th1 and Th17 cells in the total kidney-infiltrating lymphocytes was investigated by flow cytometry,and the transplanted kidney species were given routine pathological examination after fixation with 10％ formalin.ResultsCompared with the isograft group,the allograft mice showed a significantly higher content of IL-17 (P ＜0.05 ) but not IFN-γ in the serum 3 d after transplantation,and showed significantly higher serum IL-17 and IFN-γcontents 7 d after transplantation (P ＜ 0.05 ).Also,compared with the isograft group,the allograft mice exhibited significantly higher percentage of Th1 and Th17 cells on both day 3 and day 7 ( P ＜ 0.05 ).In the allograft group,the contents of serum IFN-γand IL-17 and the percentage of Th1 and Th17 cells were significantly higher on day 7 than on day 3 (P ＜ 0.05 ).Routine pathological examination indicated that,as time passed,the allograft mice showed gradually stronger rejection responses.ConclusionTh17 cells might play an important role in the development of acute renal allograft rejection,and IL-17 can be used as an early indicator of acute rejection.

Objective To study the variation of the pancreatic head arteries and its value in pan- creas transplantation.Methods The DSA data of 300 cases were studied retrospectively:192 cases of celiac trunk angiography,102 cases of superior mesenteric artery angiography,and 6 cases of the com- bined.The distribution and variation of the arteries on the pancreatic head were observed.Results In the celiac angiography cases,typical gastroduodenal artery,superior pancreaticoduodenal artery and its branches were visualized in 73 cases(38%).The posterior superior panereaticoduodenal artery was not anastomosed with the posterior inferior pancraticoduodenal artery in 3 cases.The posterior pancre- aticoduodenal arcade was discontinued in 1 case.The anterior superior pancreaticoduodenal artery, posterior superior pancreaticodoodenal artery,and dorsal pancreatic artery were only distributed across the upper head of the pancreas separately but were not anastomosed each other in 1 case.The variation rate of pancreaticoduodenal arterial arcades was 6.8%(5/73).In 102 cases of the superior mesenteric artery angiography,the inferior pancreaticoduodenal artery was visualized in 42 cases(41%)while its branches were not visualized.In 6 cases of the combined angiography,superior panereaticoduodenal artery was visualized in all of the cases,of which anterior and posterior arcades were visualized in 4 cases(66.7%).The gastroduodenal artery reconstruction was performed in 3 cases of clinical pancre- as transplantation,all of the receivers maintained a normal blood glucose level after transplantation and no surgical complications were found.Conclusions The superior pancreaticoduodenal artery might of- fer more blood supply than inferior pancreaticoduodenal artery in the pancreatic head.The arterial re- construction of the transplanted pancreas should include the gastroduodenal artery because of the pos- sibility of arterial variation on the pancreatic head.

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 observe the expression of novel URB gene in the differentiation display of 3T3-L1 preadipocytes and the effects of interleukin-6 (IL-6) and pioglitazone (PIO) on URB mRNA expression in 3T3-L1 adipocytes at different times. Method The 3T3-L1 adipocytes were treated with IL-6 and PIO under different concentration and different time phase, and real-time fluorescence monitoring RT-PCR was conducted to measure the URB mRNA level. Fat droplets were verified by oil red O staining. Results 1. URB mRNA level was increased gradually in the whole differentiation process. 2. The expression levels of URB mRNA was decreased along with the treatment of IL-6 in a dose-dependent manner in 3T3-L1 preadipocytes and adipocytes. 3. PIO increased the level of URB mRNA in 3T3-L1 adipocytes, and the reducing effect of IL-6 on URB mRNA could be corrected by PIO. Conclusion URB may be an important adipocytokin which affects energy metabolism and may work as a pharmacological gene target in the future.