Objective To study the imaging characteristics of osteosarcoma.Methods 35 patients with osteosarcoma proved pathologically were examined by radiography,of them 25 cases were examined with CT scan or MRI,and 8 cases undergone contrast-enhanced MRI.The imaging features of osteosarcoma were analysed comparatively with that of pathology.Results The lesions localized at distal part of femur in 17 cases and proximal part of tibia in 8 cases,that were most location of this tumor.The imaging characteristics of osteosarcoma included bone destruction,neoplastic bone,periosteal reaction and soft-tissue mass,in some cases,epiphyseal plate and epiphysis were involved,even the joint face and the opposite osseous of joint(skip lesions).On enhanced MR scanning,the margin of tumor was enhanced in early and the center of tumor was delayed enhancement.CT could showed "sieve sign"and small neoplastic bone.Conclusion Osteosarcoma has certain imaging characteristics;X-ray examination is the first choice in diagnosing osteosarcoma,CT and MR could provide much more comprehensive imaging information for clinic.

AIM: To investigate effects of rBMMSC on hematopoiesis and immune reconstitution after allo-hematopoietic stem cells transplantation (HSCT). METHODS: Allogeneic BMT model from Fischer344 rats (RT-1Al) to Wistar rats (RT-1Au) was established. The effects of MSCs on hematopoietic reconstitution and immune reconstitution were studied by observing the survival rate, peripheral blood counts, thymus counts, spleen counts, bone marrow counts and immune function analysis at 30 days after transplantation. RESULTS: 1. Cotransplantation of MSCs and bone marrow (BM) was demonstrated to improve hematopoietic reconstitution. Lymphocyte and platelet counts in peripheral blood in cotransplantation groups were higher than those in control groups. More bone marrow neucleated cells were also observed in cotransplantation groups. 2. Cotransplantation of MSCs and BM improved immune reconstitution. First, overall thymic cellularity and spleen cellularity significantly increased in cotransplantation groups at day 30. Secondly, cotransplantation improved immune functional recovery. Non-specific lymphocytes proliferation reaction induced by ConA and LPS increased in cotransplantation group, and so did for allogeneic mixed-lymphocyte reaction. CONCLUSION: Hematopoietic reconstitution and immune reconstitution were significantly enhanced by MSCs cotransplanted with BM.

OBJECTIVETo prevent Graft-versus-host disease (GVHD) in rat model, we evaluated the feasibility of mesenchymal stem cells (MSCs) as a gene transfer target and studied the efficiency of recombinant adenovirus mediated gene therapy.

METHODSWe constructed the recombinant adenovirus containing CTLA4Ig gene. Rat MSCs of passages 3-5 were infected by the adenovirus, and the transfection efficiency was monitored by GFP markers. We performed flow cytometric analysis, immunohistochemical and Western blotting analysis to identify the CTLA4Ig expression. The gene transferred MSCs were tested for their ability to inhibit the allogeneic lymphocyte response in vitro and to prevent GVHD in a rat model.

RESULTSRecombinant adenovirus pAd-CTLA4Ig was correctly constructed and confirmed. After MSCs were infected by the adenovirus, the CTLA4Ig protein was detected not only in transgenic MSCs, but also in the culture medium. In a mixed lymphocytes response (MLR) test, the transgenic MSCs could significantly inhibit the allogeneic lymphocyte response compared with the control groups (P < 0.05). A model of GVHD was developed by transplanting bone marrow cells and spleen lymphocytes of F344 rats to lethally irradiated SD rats. The onset of GVHD could be ameliorated or prevented by co-administration of transgenic MSCs. All the rats in the control groups suffered severe acute GVHD. CTLA4Ig expression was observed in the liver, intestine, kidney and spleen 30 days post-transplantation.

CONCLUSIONSOur results indicate that adenoviral vectors could efficiently transfer CTLA4Ig gene into MSCs and sustain long-term stable expression in vitro and in vivo.

Abatacept ; Adenoviridae ; Animals ; Feasibility Studies ; Gene Transfer Techniques ; Genetic Vectors ; Graft vs Host Disease ; prevention & control ; Immunoconjugates ; genetics ; Mesenchymal Stromal Cells ; Rats ; Rats, Inbred F344 ; Rats, Sprague-Dawley ; Recombination, Genetic