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.

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 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

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

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 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.

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.