免植骨加压延长技术一期治疗大段胫骨感染性骨缺损

目的探讨免植骨加压延长技术一期治疗大段胫骨感染性骨缺损的手术方法。方法12例感染性大段胫骨骨缺损骨折断端一期清创直接对合，近端截骨，外置重建单边重建外固定架，利用断端加压、近端骨痂牵拉延长技术免植骨治疗，定期摄X线片检查，结合患肢膝踝功能进行疗效评估。结果所有患者在去除外固定架后获平均13（8～21）个月随访，12例均一期骨性愈合，患肢膝踝功能恢复良好，按Johner-Wruhs评分标准评价：优8例，良3例，可1例。结论免植骨一期加压延长技术是治疗大段胫骨感染性骨缺损的有效方法，能降低治疗难度，缩短治疗时间。

Alpha-GalCer Administration after Allogeneic Bone Marrow Transplantation Improves Immune Reconstitution in Mice

Objective To explore the effect of α-galactosyleramide （α-GalCer） on immune reconstitution under acute graft-versus-host disease （aGVHD）. Methods BALB/c mice were transplanted with allogeneic C57BL/6 bone marrow cells and splenocytes （both 1 × 10^7） after receiving lethal total-body irradiation, α-GalCer （100 ug/kg） or vehicle （dimethyl- sulfoxide） was administered intraperitoneally immediately after transplantation. The effects of α-GalCer on immune reconstitufion, proliferation of T cells and B cells, hematopoiesis, and thymic microenvironment were assessed. Results The α-GalCer group exhibited higher percentages of CD3^＋, CD4^＋, CD8^＋, B220^＋, CD40＋, and CD86＋cells compared with the vehicle group. The number of colony forming unit per 1000 CD34^＋ cells in the et-GalCer group was higher than in the vehicle group （P=0.0012）. In vitro proliferation assays showed that the α-GalCer group had higher percentages of CD3^＋, CD4^＋, CD8^＋, and B220^＋ cells compared with the vehicle group. As for the results of in vivo proliferation assays, the numbers of CD3^＋, CD4^＋, CD8^＋, and B220^＋ cells were higher in the α-GalCer group than in the normal group, especially the number of B220^＋ cells （P=0.007）. Significant difference was not found in thymocyte count between the α-GalCer group and the vehicle group, nor in the percentages of CD3^＋, CD4^＋, and CD8^＋ cells. Conclusion Administration of tl-GalCer after allogeneic bone marrow transplantation may promote immune reconstitution in the presence of aGVHD.

T CELL REPERTOIRE COMPLEXITY IN SEVER COMBINED IMMUNODEFICIENCY PATIENTS AFTER BONE MARROW TRANSPLANTATION

Objective. To study thymus-dependent T cell development and T cell repertoire in human s ever com-bined immunodeficiencypatients after HLA-identical or haploid entical T cell-depleted allogeneic bone marrow transplantation.Methods .Blood samples were obtained from15SCID patients before transplantation and a t varying intervals thereafter.Quantitative competitive PCR assay and immunosco pe analysis of the T cell receptorVarepertoire were performed.Results. Before and within the first100days after transplantation,patients’ periphera l blood mononuclear cellpresented an oligoclonal or polyclonal skewed T cell repertoire,low T cell re-ceptor excision circlesvalues and pred ominance of CD45RO + T cell.In contrast,the presence of high numbers of CD45RA + T cells in bone marrowcirculation reconstituted SCID patients(>10 0days post-transplantation)correlated with active T cell production by the th ymus as revealed by high TREC values,and a polyclonal T cell repertoire demonst rated by a Gaussian distribution of Va-specific peaks.Conclusions.Within one year after BMT ,a normal T cell repertoire develops in SCID patients as a resu lt of thymic output.The T cell receptor diversity is highly and positively corr elated in these patients with TREC levels.

Acceleration of Immune Reconstitution after Bone Marrow Transplantation in Mice by Bone Marrow Stromal Cell Line Transfected with IL-6 Gene

To observe potential effect of the engineered bone marrow stromal cell line QXMSC1 secreting IL-6 (QXMSCIL-6) on accelerating immune reconstitution in syngeneic bone marrow transplantation in mice, QXMSC1 was transfected with the eukaryocytic expression vector pcDNAIL-6, which contained hIL-6 cDNA by liposome-mediated gene transfecting technique. G418-resistance clone was selected by limiting dilution. The highest secreting clone was selected by ELISA assay and used in animal experiments. The recipient mice (BALB/c) were lethally irradiated and cotransplanted syngeneic bone marrow (10 7/mice) and the QXMSC1IL-6 (5×10 5/mice). Lymphocyte proliferation induced by ConA and LPS, helper T lymphocyte precursor (HTLp), cytotoxic T lymphocyte precursor (CTLp), plaque-forming cell (PFC), delayed type hypersensitivity (DTH) were examined 30, 60 days in post transplantation respectively. The results showed that lymphocytes proliferation to ConA and LPS, HTLp, CTLp increased, DTH and PFC were improved by cografted stromal cells QXMSC1IL-6 on 30, 60 days after BMT. These results demonstrated that the bone marrow stromal cell line QXMSC1IL-6 transfected with IL-6 (QXMSC1IL-6) accelerated immune reconstitution in syngeneic bone marrow transplantation.

Immunological study on the transplantation of an improved deproteinized heterogeneous bone scaffold material in tissue engineering

Objective： To observe the immune response after the transplantation of a deproteinized heterogeneous bone scaffold and provides the theoretic reference for clinical practice. Methods： The fresh pig bone and deproteinized bone were transplanted respectively to establish BABL/C thigh muscle pouches model of male mice and take the samples for detection at 1, 2, 4, 6 weeks after operation. Lymphocyte stimulation index, subset analysis, serum specific antibody IgG, cytokine detection and topographic histologic reaction after implantation were investigated. Results： After the transplantation of deproteinized bone, lymphocyte stimulation index, CD4^＋ and CD8^＋ T-lymphocyte subsets, serum specific antibody IgG and cytokines in deproteinized bone group were significantly lower than those in fresh pig bone group at each time point （P〈0.05）. The histological examination found that in fresh bone group at each time point, a large quantity of inflammatory cells infiltrated in the surrounding of bone graft, and they were mainly lymphocytes, including macrophages and monocytes. In deproteinized bone group, there were few inflammatory cells infiltration around bone graft one week after operation. The lymphocytes were decreased as time went by. At 6 weeks, fibroblasts and fibrous tissue grew into the graft, and osteoclasts and osteoprogenitor cells appeared on the verge. Conclusions： The established heterogeneous deproteinized bone has low immunogenicity and is a potentially ideal scaffold material for bone tissue engineering.

Composite mandibular allografts in canines

To evaluate the feasibility of transplanting composite mandibular allografts to repair large mandibular defects. Methods: Three composite mandibular trans plantation models were established. The first model consisted of hemimandible with the attached teeth, muscle and skin,and oral mucosa. The second model was transplanted in the same way with the first one excluding oral mucosa and some teeth, and third one excluding the oral mucosa and all dental crowns. Fourteen transplanting operations were performed in canines. Cyclosporine A and methylprednisone were given for immunosuppression. Results: The composite mandibular organs had an effective and closed return circuit. Transplantation of vascularized allograft of mandibular compound organs was feasible. Two longest time survivors of 67 d and 76 d were in the third model group. Cyclosporine A was successful in suppressing rejection of transplanted composite allograft and prolonging survival time of transplantation models. Conclusions: The composite mandibular allografts were available with large block of living composite tissue, and helpful in restoration of appearance and function for severe mandibular defects.

Sustained local delivery of insulin for potential improvement of peri-implant bone formation in diabetes

Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.