Burns ; surgery ; Humans ; Skin ; blood supply ; innervation ; physiopathology ; Skin Transplantation ; methods ; Surgical Flaps ; Wound Healing

Radial Basis Function Neural Network Based on Plate Model （P-RBFNN） is constructed for resolution of chromatographic peaks of unknown components number. Then a two-phase sorting genetic algorithm (TP-SGA)-training structure and evolving is intruduced to train the network so that it has the ability of re-constructed structure. TP-SGA has robustness and random globe optimization.　The alternate use of gradient descent and TP-SGA makes the network have the ability to learn structure,　therefore makes itself adaptable to resolution of the chromatographic peaks of unknown components number.　The method proposed here needs no artificial interference,　not only has it robustness and globalism. With its characteristics related above and its ability of decomposing and analysing, this method has obvious advantages comparing with others.

BACKGROUND: The commonly used research methods of lumbar biomechanics are animal model,physical model and corpse model respectively. However, each model has its own disadvantages.OBJECTIVE: To establish the finite element model of lumbarmotionsegments in order to provide theoretical basis for biomechanical research of lumbar.DESIGN: Single sample study based on healthy volunteer.SETTING: Orthopaedic department of a university hospital.PARTICIPANTS: The experiment was completed in the Orthopaedic Department of Xiangya Hospital of Central South University from December 2003to August 2004. A healthy male volunteer was chosen as a mock object.METHODS:CT scanning was conducted to the spine(T12 - S1) of a healthy volunteer by 2 mm layer and got 264 images. The 3D model of normal Chinese male L4 5 motion segments was built by combininglumbar images scanned by CT and anatomic data through 3DSMAX software. Then it was transferred into finite elementmodel by finite element analyzing software SAP2000.MAIN OUTCOME MEASURES: ① Vertebral body model andintervertebraldisc model built by 3DSMAX software; ② Finite element model of motion segment made by SAP2000 software.RESULTS:The finite element model of lumbar L4-5 segments had been built. It had totally 2 120 nodes that include 1 728 Solid units, 592 Area units and 50 Link units.CONCLUSION: The finite element model of lumbar motion segments can be established through CT scanning, digital image processing and computer aid design to further study the biomechanics of spine.

Objective To investigate the characteristics of grafts after reconstruction of ACL with autogenous bone-patellar tendon-bone(B-PT-B)grafts. Methods Reconstruction of anterior cruciate ligament with free B-PT-B autograft fixed with interference screw was performed on 39 adult dogs. Mechanical testing was conducted on the grafts by translating the tibia anteriorly with the knee in 90 degrees of flexion, until complete failure. Failure site, cross sectional area, strength, stiffness and stress were documented. After decalcification and HE staining, the transformation of the intra-tunnel and intra-articular ligaments was evaluated, and the histological observation was conducted for the healing in the bone-tunnel, patellar tendon-tunnel and bone-patellar tendon interface. Results Union occurred in the bone-tunnel interface at 4th week. The patellar tendon-tunnel interface was linked by Sharpey's like fibers at 52nd week, the cement line and the tendency of chondrocyte lining were found. Mechanical testing of graft revealed that the rupture always occurred at mid-portion of ligaments instead of pulling-out from the tunnel under tension stress. Compared with the control group, the strength, stiffness and stress of the graft were 38%, 58% and 50% of normal anterior cruciate ligament at 52nd week respectively. Conclusion The union in the bone-tunnel interface occurs at 4th week, much earlier than the healing of the patellar tendon-tunnel interface. The healing of the tendon to tunnel presents to be indirect insertion at 52nd week with alignment of chondrocytes, which signifies the still ongoing of healing process at the interface. After fixation with interference screw for 4 weeks, the tendon proved to be the weakest part in bone-tendon-bone complex. No need to worry about the biomechanical character of the new insertion site during rehabilitation activities. The attachment fixed by interference screw is stable not only immediately after surgery but also during the healing of the insertion and the transformation of ligament. One year after reconstruction, the mechanical quality of the grafted tendon still remains inferior to that of normal anterior cruciate ligament in spite of similar histological structure. Protective device should be recommended during active activity.

Objective To investigate the biocompatibility between collagen- polyglycolic acid (PGA) and bone marrow mesenchymal stem cells (MSCs) in vitro to provide some experimental basis for further study in tendon tissue engineering. Methods MSCs were isolated, cultured and characterized. In the experimental group the MSCs were cultured in DMEM containing type-I collagen and PGA suture, and in the control group the MSCs were cultured in DMEM. The cell growth was compared between the two groups, and the cell ultramicroscopic structure of experimental group was observed. Results MSCs grew well in the collagen-PGA scaffold, and 2 weeks after incubation they still kept secretion potential and more than cell 89% vitality, which were not significantly different compared with the control group. There is no statistical difference in the MSCs count in the experimental group during 2 weeks culture, while in the control group MSCs began to proliferate at the 4th day after culture. Conclusion Collagen-PGA has a good biocompatibility with mesenchymal stem cells. It is possible to fabricate a tissue-engineered tendon in vitro using mesenchymal stem cells as seed cells and collagen-PGA as scaffold.

Objective To discuss the effect of nicotine on the growth of rabbit tendon cells.Method 1% concetration Nicotine(0 5ml/kg) was injected into rabbit's auditive vein,then femoral vein blood was extracted at 3 minutes later. Separating blood serum and add it into F-12 medium and 10% fetal bull serum,penicillin,streptomycin,vitC which was then used to culture rabbit tendon cells, observating the time of cell number growth duplication of test group and drawn up its growth curve. The control group was treated as the test group except the rabbit was not injected by nicotine.Results The time of cell number growth duplication of test group was 9?2 1 days and the control group was 7?1 1 days,there was difference significatly between the two groups.Conclusion Nicotine can restrain the growth of rabbit tendon cells and enhance tendon's adhesiveness in post-operation.

50%),including 22 complicated with hypertension cases were retrospectively analyzed and statistics their fluid infusion volume,serum albumin levels serum sodium,blood sugar and general infections conditions were summarized,and compared with non-hypertension cases.Results The difference of fluid infusion volume between them was no significance in statistics.The difference of serum Na +,blood sugar,serum albumin levels between them was significant.All of 22 cases of hypertension had toxemia symptom,12 of 22 cases in control group occured toxemia symptom,morbidity peak of hypertension was accorded with infection morbidity peak.Conclusions General infection after burns could play an important role during the happening of hypertension after burns. We should pay more attention to the therapy of infection in treatment period.

To investigate the feasibility of using limited flap to repair different wounds by using fractionated transfer of one flap to repair different wounds in 8 cases. Among them, 2 cases were pedicle iliolumbar skin flaps, 2 cases were pedicle iliolumbar and hypogastric combined skin flaps, 2 cases were free latissimus dorsal myocutaneous flaps, 1 case was gastrocnemius myocutaneous flaps, and 1 case was deltopectoral skin flap. The flap in donor area was isolated normally, and then transferred to repair the main wound or the wound following scar excision. The other remnant wounds were treated by using thorough debridement. Blood supply training was performed from two weeks after operation. When the flap had reliable blood supply, a second-stage operation was performed. The remnant wounds were repaired by anterograde or reversed transfer. According to the ways of the second-stage operation, blood supply training and dissection of the pedicles were performed at 2 weeks after operation in some of the patients. All these flaps survived, and the wounds were repaired with satisfactory. The appearances and functions were improved after a six months follow-up. Results suggested that it was safe and feasible to use the same pedicle repaired different parts, which can solve the problem of using limited flap to repair different wounds.

AIM: Previous studies paid more attention to the effect of fibroblast immigration in normal surrounding tissue or blood on wound healing. This study explored the morphological character of fibroblasts after heat injury to support the new operation of autogenous epidermis overlapping denatured dermis. METHODS: The experiment was performed at the State Key Laboratory of Trauma, Burn and Combined Injury in the Third Military Medical University of Chinese PLA from April 2006 to April 2007. The dermal fibroblast from the infant prepuce disposed after surgery was cultured in vitro, and divided into 2 groups. In normal group, the dermal fibroblasts were put in water bath at 37 ℃ for 30 seconds; the cells in experimental group were stimulated at different temperatures (50, 51, 52, and 53 ℃) for different time (30, 60, 90, and 180 seconds). Cell survival was detected by MTT; morphology of injured cells were observed under inverted microscope and transmission electron microscope at 3 hours, 1, 2, 3, 4, 5, and 7 days; cell cycle was detected by flow cytometry. RESULTS: At different temperatures and different time, there were significant differences in the survival rate of fibroblast between the experimental groups and normal group (P

Objective:To investigate the clinicopathological and immunohistochemical characteristics of soft tissue mesenchymal chondrosarcoma. Methods:The clinical material,pathological and immunohistochemical characteristics(reactiontoLCA,CD3,CD20,CD45RO,CD79a,CD99,NSE,S-100,Syn,CgA,CK7,CK19,EMA,Coll-Ⅱ,Sarcomeric-Actin,Desmin,Ki-67,P53) of 2 cases of soft tissue mesenchymal chondrosarcoma in Jishuitan Hospital between 1995 and 2005 were reviewed and followed up. Results:The two patients were both females. The tumors were located in the low extremity muscles. The main roentgenographical appearance was stippled calcification in tumor and calcification at the edge of the tumor. The histological characteristic features showed undifferentiated small cells together with islands of chondrosarcoma;there was hemangiopericytoma-like arrangement of small cells.The tumor cells were positive for CD99,NSE,Syn,CgA;The cells in chondroid matrix were positive for S-100;chondroid matrix was positive for Coll-Ⅱ. All tumor cells were negative for LCA,CD3,CD20,CD45RO,CD79a,Sarcomeric-actin,Desmin and CK7,CK19, and EMA. The patient with followed radiotherapy was alive. and the other without radiotherapy dead. Conclusion: Mesenchymal chondrosarcoma of soft tissue has the characteristics of primary mesenchyme which differentiates to congenital cartilage. The pathological characteristics of bimophic pattern and roentgenographical appearance of tumor are useful for diagnosis.The prognosis is poor.