The study of mechanical properties on heart valves can provide an important theoretical basis for doctors to repair heart valves and prosthetic valve materials research. In this paper, we present the current status of the mechanical property study methods of heart valve, expound the methods and special requirements about uniaxial tensile test and biaxial tensile test of the heart valve, and further discuss several establishment methods of heart valve constitutive models. We also discuss the development trend of heart valve mechanics.
Heart Valve Prosthesis ; Heart Valves ; physiology ; Humans ; Prostheses and Implants

Objective To investigate the operative techniques and clinical significance in the treatment of large area soft tissue defect in children limbs by sequential vacuum-assisted closure and free flaps. Methods Twenty-two cases of children patients, with a range between 3 and 10 years, were treated by sequential vacum-assisted closure (VSD) and free flaps. All the patients suffered from large area soft tissue defect after severe trauma of limbs, with bone, tendon and other deep tissues exposed or partial defected. The wound area varied from 12 cm × 8 cm to 34 cm × 25 cm, and among the wound 9 cases were fresh and the other 13 were necrotizing infection. After strictly cleaned, the wound was covered with VSD according to the condition of the soft tissue defect and its underlying tissue damage. For the patients complicated with unsteady fracture, the fracture was fixed with outside-fixed frame or inside-Kirschner nails. The VSD negative pressure membrane was removed after 5 to 9 days, then the wound was repaired by free flaps grafting in 8 cases and by free flap combined with skin grafting in the other 14 cases. The survival and recovery conditions were followed up after the operation. Results After treatment by VSD, no obvious infection was seen in 22 cases of children patient with large area soft tissue defect complicated by underlying tissue exposure, and granulation tissue surrounding tendons and bone exposure area grew well. The survival rate of the free flaps was 100% whithout vascular crisis.The infection was well controlled, and no fistula tract was seen. The patients were followed up for 6-24 months and the flaps had soft texture and good appearance with satisfactory functional recovery of the affected limbs.Conclusion For pediatric patients with large area soft tissue defect complicated by underlying tissue exposure, after strict debridement, the treatment circle will be obviously shortened by the application of sequential vacuan seding dranage and microsurgical technique, and the success rate of the operation is improved. Therefore, function of the affected limbs in children will be recovered as far as possible.

ObjectiveTo evaluate the safety,therapeutic effect and complications of the operation of multi-section osteotomy and intramedullary fixation for children with osteogenesis impeffecta.Methods One hundred and twenty-three children with osteogenesis imperfecta,including 85 males and 39 females,were selected from August 2005 to August 2008.According to the modified Sillence classification,45 cases was in type Ⅲ,74 in type Ⅳ,and 5 in type Ⅴ.Patients' age was ranging from 2 years and 1 month to 15 years and 7 months (mean,8 years and 3 months).The location of osteotomy was established according to the pre-operative measurement of X-ray image,and all the procedures of osteotomy were completed under direct vision.Then we chose the intramedullary pin with suitable size and insert the pin into femur from greater trochanter,and tibia from pelma.After the surgery,external fixation (spica cast for the femur,long leg plaster cast for the tibia) was made for further stabilization.Plaster supporters were removed 6 weeks later and all children began to stand and walk under the protection of orthoses.In addition,all patients received the treatment of pamidronate disodium periodically.ResultsAll 123 children were followed up for an average of 38months (range,13-64 months).Parents of all children were satisfied with the result of surgical operation,and the children's self-care and motion ability improved obviously.Fourteen children were performed the second operation due to the translocation of Rush pin,and 25 children changed the internal fixation because of the shorter Rush pin 2 years postoperatively.Bone delayed union was not found in all patients.Conclusion Multi-section osteotomy and intramedullary fixation for children with osteogenesis imperfecta could correct skeletal deformity,improve motion ability and avoid second fracture efficiently.However,such complications as translocation of intramedullary pin and changing the internal fixation with the growth of child need to pay more attention.

Since 1970's , lots of studies on biodegradation of chloroanilines (CAS) have been done, especially, in these aspects: spieces and capability of the microbes; metabolic pathway; gene cloning, expression of degradation plas-mid and pivotal metabolic emzymes. It is necessary for us to review the study on biodegradation of chloroanilines in order to summarize some useful results and the problems in this study.

ObjectiveTo study the role of alpha smooth muscle actin (α-SMA) positive cells (pericytes)in early myocardial ischemia.MethodsThirty healthy female Wistar rats were randomly divided by body weight into normal control group and subcutaneous multi-point injection of isoprenaline(Isp) group.Five rats were anesthetized after 0,2,4,6,12,24 and 48 h in each group.Blood was taken in eyeballs and,serum was separated,heart was taken and fixed in 4％ paraformaldehyde solution.The myocardial enzymes [serum apartate aminotransferase ( AST ),lactate dehydrogenase (LDH),creatine kinase (CK),creatine kinase isoenzymes (CK-MB)] were determined by biochemical automatic analyzer,the expression of α-SMA and vimentin in myocardial tissue was detected by immunohistochemical staining and changes of pericytes in early myocardial ischemia was observed by morphometric analysis.ResultsThe level of myocardial enzymes AST[(160.25 ± 3.86),(172.60 ± 8.82),(192.20 ± 25.35)U/L],and LDH[(1466.25 ± 643.38),(1645.20 ± 326.83),(1701.60 ± 640.06)U/L],12,24 and 48 h after subcutaneous injection of Isp,were higher than that[(129.18 ± 19.65),(849.45 ± 248.54)U/L,all P ＜ 0.05] of the control group.The level of CK[(1097.60 ± 301.57),(1247.20 ± 243.84),(1263.75 ± 271.22),(1448.00 ± 647.00),(1268.40 ± 479.81)U/L],and CK-MB[(217.12 ± 35.89),(229.08 ± 97.11),(251.70 ± 46.82),(318.80 ±77.76),(249.04 ±:98.54)U/L],4,6,12,24 and 48 h after subcutaneous injection of Isp,were higher than that [(713.45 ± 146.30),(147.05 ± 25.75)U/L,all P ＜ 0.05] of the control group.The number of α-SMA positive cells(61.00 ± 17.25),4 h after Isp injection,was significantly increased compared with that(28.20 ± 5.81,18.20 ± 2.17) of 24 and 48 h after Isp injection.The number of α-SMA positive cells in 48 h group was less than that(50.00 ± 3.61,P ＜ 0.05) of 6 h group.The number of vimentin positive cells in 6,12,24,48 h groups (4.17 ± 2.49,5.24 ± 2.84,8.37 ± 2.18,7.73 ± 2.49) were higher than that(1.88 ± 1.85,2.21 ± 1.54) of the control group and 4 h group(all P ＜ 0.05).Compared with 24 and 48 h groups,the level of vimentin protein was increased in 6 and 12 h groups(P ＜ 0.05).ConclusionThe number of pericytes in early myocardial ischemia is higher than that of other mesenthymal cells,and pericytes may be the main effector cells in the generation and development of myocardial fibrosis.

Objective To evaluate the application effect and value of four kinds of neuroendoscopic operation mode in the treat-ment of hydrocephalus .Methods The four kinds of neuroendoscopic operation mode ,including endoscopic third ventriculostomy , septostomy of the septum pellucidum ,cyst ventriculostomy and ventrideperitoneal cavity ,were selected in 58 cases of hydrocephalus according to the indications .The treatment effects were analyzed and the application value was evaluated .Results Among 58 cases of hydrocephalus ,50 cases were significantly improved after operation ,the total effective rate was 86 .21% ,2 cases appeared some complications .The four kinds of operation mode could better treat hydrocephalus .Conclusion Neuroendoscopy is an ideal method in treating hydrocephalus and has the advantages of the slight trauma and fewer complications ,which is a method deserving to be promoted in clinic .

Hemodynamic situation is an important factor of recurrence of postoperative carotid artery aneurysm. In order to investigate the hemodynamic factors of postoperative carotid artery aneurysm affect carotid artery aneurysm recurrence, we established a 3D finite element carotid artery aneurysm for the preoperative and postoperative periods using the three-dimensional reconstruction techniques. And then we measured the hemodynamic factors of carotid artery aneurysm of preoperative and postoperative by the finite element method. The carotid artery aneurysm model has an accurate and realistic shape; the pressure of the recurrence of aneurysm was reduced significantly after surgery,wall shear stress increased significantly at residual neck, and blood flow velocity increased significantly, which will increase the risk of recurrence. The hemodynamic analysis provides a reference for development of aneurysm clinical treatment programs and prevention of recurrence.
Aneurysm ; pathology ; surgery ; Blood Flow Velocity ; Carotid Arteries ; pathology ; surgery ; Computer Simulation ; Hemodynamics ; Humans ; Stress, Mechanical

Objective:To investigate the effect of piggyBac transpon,as a carrier of four defined transcription factors Oct4,Sox2,Klf4 and c-Myc,in the reprogramming of mouse embryonic fibroblasts (MEFs)to induced pluripotent stem cells (iPSCs).Methods:The MEFs were isolated from Oct4-GFP fetal mice and transfected by piggyBac transposon with four factors (Oct4,Sox2,Klf4 and c-Myc).The morphological changes of clones were traced with microscope during the process of induction.The chromosomes were analyzed to evaluate the karyotypic variation of iPSCs.The mRNA expressions of Oct4, Nanog and FGF4 associated with embryonic stem cells (ESCs)in the iPSCs of mice were tested by RT-PCR;the protein expressions of SSEA-1,Nanog and Alkaline phosphatase in the iPSCs of mice were determined by flow cytometry,immunofluorescence and AP staining.The iPSCs were transplanted into the NOD-SCID mouse groin,4 weeks later,the teratomas were removed for HE staining and the differentiation of tissue was observed.Results:The iPSCs were successfully obtained from MEFs by piggyBac carrying Oct4,Sox2,Klf4,and c-Myc.The round or oval iPSCs clones were similar to ESCs with clear boundry and large dense nuleus.The iPSCs showed the normal karyotypic and expressed the marker genes (Oct4,Nanog and FGF4)and proteins (SSEA-1,Nanog and AP)of ESCs.Teratomas containing three germ layers were formed in NOD-SCID mice after tanspalantation of iPSCs.Conclusion:The iPSCs are reprogrammed from MEFs by piggyBac transposon with four transcription factors-Oct4,Sox2,Klf4 and c-Myc,and the iPSCs with normal karyotype possess the characteristics of ESCs.

Objective To discuss an initial clinical application of three-dimensional reconstruction of ilium bone flap. Methods From December 2006 to June 2008, bone defects of 6 patients with frac-tures of femoral shaft and tibia were repaired using vascularized iliac bone flap. After injection of contrast a-gent, CT scan was performed. Amira 4.0 Software was applied to reconstruct personalized three-dimensional structures of the iliac bone flap. The points, lines, and surfaces were marked in the personalized three-dimensional images reconstructed to provide guidance for the actual surgery. Results The person-alized three-dimensional reconstruction of iliac bone flap for the 6 individual patients were successfully used in the actual surgery. The three-dimensional structures of blood vessels, bone and adjacent relationship which had been clearly shown in the reconstructed flaps were confirmed by the actual surgical findings. All the 6 lilac bone flaps survived uneventfully. Conclusion The preoperative three-dimensional reconstruction of lilac bone flap by CT scan, angiography and digital technology can provide a useful aid for actual surgical design and harvest of the flap, minimizing intraoperative injury to blood vessels and enhancing flap survival.

OBJECTIVETo observe the changes in Aβ40, Aβ42 and ADDLs in brains of 3 month-old APPswe/PS1dE9 double transgenic mice after six-month intervention with curcumin, in order to discuss the neuroprotective effect of curcumin.

METHODAPPswe/PS1dE9dtg mice were randomly divided into the model group, the Rosiglitazone group (10 mg x kg(-1) x d(-1)) and curcumin high (400 mg x kg9-1) x d(-1)), medium (200 mg x kg(-1) x d(-1)) and low (100 mg x kg(-1) x d(-1)) dosage groups, with C57/BL6J mice of the same age and the same background in the normal control group. After 6 months, the immunohistochemical staining (IHC) and the Western blot method were used to observe the changes in positive cell of Aβ40, Aβ42 and ADDLs in hippocampal CA1 area, their distribution and protein expressions.

RESULTBoth of the immunohistochemical staining and the Western blot method showed more positive cell of Aβ40, Aβ42 and ADDLs in hippocampal CA1 area and higher protein expressions in the model group than the normal group (P < 0.01). IHC showed a lower result in the Rosiglitazone group than the model group (P < 0.05), while Western blot showed a much lower result (P < 0.01). The number of Aβ40, Aβ42 and ADDLs positive cells and the protein expressions decreased in the curcumin high group, the medium group showed a significant decrease (P < 0.01), and the low dose group also showed reductions in the protein expressions of Aβ40 and Aβ42.

CONCLUSIONThe six-month intervention with curcumin can significantly reduce the expressions of hippocampal Aβ40, Aβ42 and ADDLs in brains of APPswe/PS1dE9 double transgenic mice. Whether curcumin can impact Aβ cascade reaction by down-regulating expressions of Aβ40, Aβ42 and ADDLs and show the neuroprotective effect needs further studies.

Alzheimer Disease ; drug therapy ; genetics ; metabolism ; Amyloid beta-Peptides ; genetics ; metabolism ; Animals ; Brain ; drug effects ; metabolism ; Curcumin ; administration & dosage ; Disease Models, Animal ; Hippocampus ; drug effects ; metabolism ; Humans ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Neuroprotective Agents ; administration & dosage ; Plant Extracts ; administration & dosage