Biomedical subjects

Jianzhong Xu

Publications and source records attributed to Jianzhong Xu.

5 recordsLinked to original sources

PubMed2006

hCTLA4-gene modified human bone marrow-derived mesenchymal stem cells as allogeneic seed cells in bone tissue engineering.

Immune rejection of heterogeneic seed cells, even of low antigenicity human bone marrow derived mesenchymal stem cells (hBMMSCs), remains an obstacle for bone tissue engineering. It is still a question how to transfer the gene of human cytotoxic T lymphocyte-associated antigen 4-Ig (CTLA4-Ig), a well-known ligand for CD80/CD86, to hBMMSCs to prolong survival time while not interfering with their osteogenesis in vivo. Our data, for the first time, clearly demonstrate that CTLA4-Ig gene modified hBMMSCs could normally differentiate to osteoblasts in vitro, significantly inhibit immune response in the model of mixed lymphocyte culture, and survive until bone tissue formed in vivo. Thus, CTLA4Ig gene-modified hBMMSCs might be promising seed cells for bone tissue engineering.

Animals↗

PubMed2006

[Setup a model for study the interfere between chemokine and immunocyte].

OBJECTIVE: To investigated the effect of chemoattractant of rhTNF-alpha on TB-LCL. Set up a model for study the interaction between cytokine and B cells. METHOD: PTC were transfected with Epstein Barr virus, to get tonsil B lymphoblastic cell line(TB-LCL). RESULT: It was found rhTNF-alpha can chemotactic TB-LCL, in a dose-dependent manner and this chemotactic effect can be blocked by the neutralizing antibody E6 against TNF. CONCLUSION: This is an useful model in study the interfere between chemokine and immunocyte.

B-Lymphocytes↗

PubMed2003

Immortalization of human articular chondrocytes and induction of their phenotype.

OBJECTIVE: To immortalize human articular chondrocytes (HACs) using gene transfection and to maintain stable phenotype of transformed HACs after induction. METHODS: HACs were transfected with the retroviral vector pLXSN encoding human papillomavirus 16E7 (HPV16E7), and the transformed clones were sorted and proliferated. Karyotype analysis, clone forming tests and nude mice tumor forming tests were applied to check the characteristics of the transformation. Type II collagen of transformed chondrocytes was inducted with free serum medium (FSM) supplemented with nutridoma-sp and ascorbate. RESULTS: Immortalized HACs were isolated with fifty passages achieved. The HPV16E7 transformed cells were confirmed to be benign. Induction of FSM with nutridoma-sp and ascorbate promoted type II collagen of transformed chondrocytes to the high levels of normal chondrocytes. CONCLUSION: HACs transformed with HPV16E7 survive for long periods in vitro, and type II collagen can maintain stability after induction.

Cells, Cultured↗

PubMed2002

[Treatment of complex bone nonunion with external skeletal fixation].

OBJECTIVES: To summarize the experience in the treatment of 112 cases of complex bone nonunion from 1982 to 1999 in our department and introduce the technique of external skeletal fixation. METHODS: The two fragment ends of all cases were fixed under pressure with half-ring sulcated external skeletal fixator. Those cases complicated by bone defect or limb shortening were operated on with epiphysiotomy to restore the length of the limb in the period of compressive fixation or after the occurrence of bone union according to the condition of complicated infection and the length of the limb shortened. RESULTS: The nonunion of the 112 cases was united eventually. The infection in 34 cases was eradicated. Bone union in cases without infection took 3 approximately 7 months (average 5.2 months) and in cases with infection took 5 approximately 11 months (average 5.5 months). The length of the limb in 11 cases with bone defect was restored in the same period of compressive external fixation and another 8 cases achieved after bone union. The length between the injured and healthy limbs was balanced. CONCLUSIONS: When external skeletal fixation is employed to treat those troublesome cases of bone nonunion, the pins for fixation are inserted in sites far from the lesions and the non-united fragment ends are exposed only in the area without scars. Consequently, there is little interference with the blood circulation and the osteogenic potency of the fragment ends. The sclerotic bone tissue is not excised, the marrow cavity is not chased to be open and the fragment ends are only moderately modified. As a result, the stability of fixation is increased and further shortening of the limb avoided. External skeletal fixation using small pins with cross penetration results in plastic fixation and promotes bone healing. Bone lengthening with epiphysiotomy can restore the balance of the limbs.

Adolescent↗

PubMed2002

[Effects of Atractylodes macrocephala seeds coated with SCF on field diseases].

The field plot experiments were designed with L9(3(4)) orthogonal comparison to study the effects of Atractylodes macrocephala seeds coated with SCF on field diseases. The results showed that the treatment 2 was the best SCF to control field diseases. The treatment of seed-coating with thiophanate methyl reduced the percentage of field diseases significantly.

Analysis of Variance↗