Abstract： Diseases prognosis is often influenced by multiple factors, and some intricate non-linear relationships exist among those factors. Artificial neural network （ANN）, an artificial intelligence model, simulates the work mode of biological neurons and has a b capability to analyze multi-factor non-linear relationships. In recent years, ANN is increasingly applied in clinical medical fields, especially for the prediction of disease prognosis. This article focuses on the basic principles of ANN and its application in disease prognosis research.
OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
Objective To explore the effect of minimally invasive and mini-incision surgery (MIS) in total hip arthroplasty (THA) on late osteonecrosis of femoral head (ONFH). Methods From March 2003, Eighteen patients (22 hips) with ONFH underwent MIS in THA. Their ages ranged from 24to 57 years, including 13 males and 5 females. The mean body mass index ranged from 17.1 to 30.1(24.6 on average). The Harris hip score was 46 points before operation. Modified posterior-lateral approach was adopted, and the MIS THA was performed by cementless prosthesis. As a comparison, 18 patients (22 hips) were performed by conventional THA at the same period. The data, including bleeding volume during operation, incision length, operative time, and postoperative function recovery, were compared. Results Follow-ups were done for 6 to 20 months (11 months on average). Dislocation occurred in one patient that underwent conventional THA 2 days after operation. No complication occurred in MIS THA group. The incision lengths ranged from 8.7 to 10.5 cm (9.3 cm on average) in MIS THA group, being statistically different (Plt;0.01). There was no significant difference in Harris scoring of the function between the two groups both before the operation and after the operation (Pgt;0.05). The operative time was almost the same, but the bleeding volume in MIS THA group was less (Plt;0.05). The function recovery was faster in MIS THA group.Conclusion The MIS THA is an alternative to the treatment of late ONFH. The advantages of MIS THA are fewer trauma, less bleeding volume, and faster recovery. The MIS THA should be performed by surgeons with rich experiences in THA and hospitals with necessary instruments.
Objective To study the feasibility of transplanting human saphanous vein endothelial cells to luminal surface of blood vessel prosthesis and to play a theoretical foundation for the clinical application of autologous endothelial cell transplantation. Methods Human saphanous vein endothelial cells were harvested with 0.1% collagenase and cultivated in vitro for 13.08±1.24 days. The cultures were confirmed as endothelial cells with the fourescent linked anti-Ⅷ antigen antibodies. The content of both 6-keto-PGF1α and Von Willebrand factor (vWF) in the supernatant were detected with ELISA and radioimmunoassay. The multiplied cells were lined in vitro onto the luminal surface of expanded polytetraflouroethylene (ePTFE) grafts precoated with fibrin glue and fibronectin, then cultivated again for 9 days. Results 11.46±2.69×１０６ of available endothelial cells could be regularly obtained, the number of endothelial cells increased 147.93±88.68 times when culture were terminated. All the cells diploid cells with a purity of 99%. The content of both 6-keto-PGF1α and vWF in the media showed no significant difference between the primary and subculture passages. The luminal surface of grafts was covered completely by a spindlelike endothelial monolayer and an even fibrin glue matrix could be seen underneath. Conclusion Endothelial cells derived from human saphanous veins might be feasible to be transplanted onto the luminal surface of ePTFE and present a potential clinical application.
OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
Objective To understand the value of pre-coating in artificial vessel endothelialization. Methods Literature concerning precoating in artificial vessel endothelialization was extensively reviewed. Results Pre-coating included chemical coatings(collagen, fibronectin, laminin, poly-l-lysin, gelatin andextracellular matrix), pre-clotting(plasma, blood, serum and fibrin glue), chemical bonding (heparin, RGD and lectins) and surface modification. Most of them could enhance the adhesion of the endothelial cells. Conclusion Pre-coating couldimprove endothelialization, but further research is needed to search for the appropriate concentration and incubation time.
Objective To study the cl inical appl ication of Mobi-C prosthesis in treatment of anterior cervical discectomy and artificial disc replacement (ADR). Methods Between January 2009 and June 2009, 20 cases of degenerative cervical disease were treated with anterior discectomy and ADR by Mobi-C prosthesis, including 13 cases of cervical disc herniation and 7 cases of cervical spondylotic radiculopathy, and 25 Mobi-C prosthesis were implanted. There were 8 males and 12 females, aged 29-54 years (mean, 45.2 years). The disease duration was from 4 days to 5 years (mean, 1.2 years). Affected segments of process included C3, 4 in 1 case, C4, 5 in 2 cases, C5, 6 in 7 cases, C6, 7 in 5 cases, C4, 5 and C5, 6 in 2 cases, and C5, 6 and C6, 7 in 3 cases. Radiographs were taken regularly, and cervical range of motion (ROM) on segments of disc replacements were measured. The functions of cervical spinal cord were evaluated by “40 score” system (COA) preoperatively, immediately postoperatively, and at follow-up. The qual ity of l ife was evaluated by neck disabil ity index (NDI) and visual analogue scale (VAS) score. Results All incisions healed by first intention. No perioperative compl ication was found. All cases were followed up 16.5 months on average (range, 14-18 months). There was no significant difference in cervical ROM of operatied segment between preoperation and follow-up duration (t=0.808，P=0.440). No heterotopic ossification was found at follow-up. COA score at last follow-up (38.20 ± 1.14) was significantly higher than preoperative one (32.10 ± 2.96) , (t=9.278，P=0.000) , and the improvement rate at last follow-up was 77.2% ± 5.4%. VAS score at last follow-up (3.20 ± 1.23) had significant difference when compared with preoperative one (5.10 ± 1.29), (t=10.585，P=0.000). NDI score at last follow-up (29.40 ± 4.55) had significant difference when compared with preoperative one (39.20 ± 3.80), (t=16.039, P=0.000). Conclusion A satisfactory short-term curative effect can be obtained by using Mobi-C prosthesis in treatment of anterior cervical discectomy and ADR.