Biomedical subjects

Weidong Tian

Publications and source records attributed to Weidong Tian.

28 records · Page 2Linked to original sources

PubMed2003

[Effect of distraction osteogenesis on circadian rhythm of proliferation index of mandibular osteoblast in goat].

OBJECTIVE: The study was to investigate the circadian rhythm of the proliferation index (PI) of the mandibular osteoblast after distraction osteogenesis (DO) by a comparative study to explain the different rhythm characteristics. METHODS: Forty-eight healthy goats were employed and divided randomly into DO group and control. Four weeks after the right side mandible of DO group was distracted, animals of the both groups were killed at 0:00, 4:00, 8:00, 12:00, 16:00, 20:00 time point subsequently. Samples of 2 cm x 2 cm x 0.5 cm bone tissue were excised from distracted zone of DO group and the right mental foramen zone of the control. Primary cell culture method was employed to isolate the osteoblast from bone tissue and a flow cytometric analysis was used to detect the PI of osteoblast. The data was analyzed with cosinor rhythmometry method and the different rhythm between the two groups were investigated. RESULTS: The PI in the two groups demonstrated cosinor waves. The mesor and amplitude in DO group were significant higher compared with the control(P < 0.05), but there was no significant difference for the acrophase between the two groups (P > 0.05). CONCLUSION: The PI of osteoblast after DO showed significant circadian rhythm. It is suggested that DO is helpful to promote osteoblast proliferation and bone regeneration.

Animals↗

PubMed2003

[An experimental study on circadian rhythm of the proliferative index of mandibular osteoblast in goats].

OBJECTIVE: The aim of this study was to investigate the circadian rhythm of the proliferative index of mandibular osteoblasts of goats in a normal situation. METHODS: Twenty four healthy goats were selected and randomly divided into six groups. They were killed, and a piece of bone tissue with 2 cm x 2 cm x 0.5 cm was obtained from right mandibular mental foramen region at 0:00, 4:00, 8:00, 12:00, 16:00 and 20:00 time points, after they had been fed for one week. The primary cell culture method was used to cultivate osteoblasts from the bone. The method of anti-5-bromodeoxyuridine monoclonal antibody and the flow cytometric analysis were used to detect the proliferative index of the mandibular osteoblasts at different time. The data were analyzed using the method of single cosine rhythmometry. RESULTS: The proliferative indexes of the mandibular osteoblasts of goats were higher at the nighttime and lower in the daytime. The undulation of the proliferative indexes displayed a significant circadian rhythm (P < 0.01). The peak value was obtained at about 19:44, and the lowest value at about 7:44. CONCLUSION: The proliferative indexes of the mandibular osteoblasts of goats are not stable within 24 hours in a normal situation, but with significant circadian rhythm. There are different proliferative indexes at different time points.

Animals↗

PubMed2003

[An experimental study on gene transfection of human interleukin-1 receptor antagonist gene into chondrocytes of temporomandibular joint].

OBJECTIVE: The purpose of this study was to investigate methods and expression of the recombinant human interleukin-1 receptor antagonist gene transfected into chondrocytes of temporomandibular joints (TMJ). METHODS: Chondrocytes derived from the TMJ of 5-7 months old human fetus were transfected by recombinant human interleukin-1 receptor antagonist gene via cationic liposome (Lipefectine) as a medium. The expressing level of hIL-1ra protein was detected using immunocytochemistry and enzyme-linked immunosorbent assay (ELISA). RESULTS: The positive results of the immunocytochemistry were found. The positive expression was detected in the cell plasma and the cell culture supernatant, and there was significant difference between the cells with and without gene transfection (P < 0.01). CONCLUSION: This feasible method provides experimented evidence for the future gene therapy of temporomandibular joint osteoarthrosis.

Chondrocytes↗

PubMed2003

[A study on puncturing the temporomandibular joint cavity of rabbits and withdrawing synovia].

OBJECTIVE: The purpose of this study was to study the methods of how to puncture the temporomandibular joint (TMJ) cavity of rabbits and get the synovia. METHODS: The authors punctured joint cavity and withdrew the synovia from bilateral TMJ cavities of 12 New Zealand rabbits with different methods, such as the traditional puncture method, improved puncture, puncture under X ray, puncture guided by ultrasonography and spiral CT, and withdrawing synovia by micropump. RESULTS: Only one cavity was successfully punctured using the traditional puncture method. A total of 4 cases were successfully punctured using the improved method. X ray and ultrasonography did not locate the TMJ cavity precisely. The spiral CT helped observation and puncture. However, the above methods did not work in collecting synovia. The method of micropump withdrew synovia successfully. CONCLUSION: The improved method and spiral CT are efficient methods to precisely puncture TMJ cavity. The technique of micropump successfully resolves the problem of withdrawing synovia.

Animals↗

PubMed2003

[Experimental studies on the poly-hydroxybutyrate membrane modified by gamma-radiation and mixed with calcium sulfate].

The objective of this study was to learn the property of poly-hydroxybutyrate membrane (PHBm) modified by gamma-radiation and mixture of calcium sulfate, and to explore the possibility of using modified PHBm for guided tissue regeneration (GTR). The PHB was treated by 5 KGy gamma-radiation and mixed with 1/10 calcium sulfate. The modified PHB membrane was prepared by solvent-casting techniques. The mechanical properties and molecular weight of the modified PHBm were tested. Degradability of the modified PHBm was analyzed in vitro in a buffer solution of KH2PO4-Na2HPO4. Biodegradability and biocompatibility of the modified PHBm were inspected 1, 2, 3 and 6 months after the embedding of the modified PHBm into dogs. The morphology was analyzed by scanning electron microscopy (SEM) and molecular weight was tested to evaluate the biodegradability of PHBm. Biocompatibility of the modified PHBm was observed through tissue response by light microscopy. The extension strength and the extension strain at fracture of the modified PHBm were 23.8 MPa and 1.0% respectively. The morphologic observation of the modified PHBm at different terms showed that the modified PHBm was biodegraded gradually in vitro and in vivo. The capsule surrounding the modified PHBm was mainly composed of fibrocytes and few lymphocytes. The longer the time elapsed, the thinner the capsule enveloping the modified PHBm grew. The modified PHBm possesses satisfactory mechanical properties and biocompatibility, and it is biodegradable in vitro and in vivo. The modified PHB membrane could be applied as GTR membrane.

Animals↗

PubMed2003

[Heterotopic osteogenesis of autogenous marrow stromal cells with recombinant human bone morphogenetic protein 2 gene transfection and porous calcium phosphate ceramic as a scaffold].

OBJECTIVE: To observe the heterotopic osteogenesis of autogenous marrow stromal cells loading on porous calcium phosphate ceramic scaffolds with rhBMP2 gene transfection in a Sprague-Dawley rat model. METHODS: Autogenous marrow stromal cells were obtained from left femurs and tibias of 20 male adult SD rats under general anesthesia and sterile condition and cultured in alpha-Minimal Essential Medium supplemented with 15% fetal bovine serum. RhBMP2 gene was transfected into stromal cells by means of LipofectAMINE 2000 reagent five days after primary culture. The stably gene expressive cells were selected with G-418 for 14 days and mixed with stromal cells without transfection. The mixture cells were seeded and subcultured for another 10 days in porous calcium phosphate bioceramic that had been subjected to surface-modification via soaking in human plasma fibronectin. The cell-ceramic compound was implanted subcutaneously and intramuscularly in the corresponding rat. Lab animals were sacrificed at two-week intervals till twenty weeks postoperatively and the involved samples were removed. RESULTS: Morphologic and histological study demonstrated that cell-ceramic compound had an ability of heterotopic osteogenesis, which was similar to that of autogenous osteoblasts in previous study. CONCLUSION: It seems that autogenous stromal cells with rhBMP2 transfection acts as a bioreactor promoting proliferation and differentiation of stem cells when they are replanted into the corresponding animals.

Animals↗

PubMed2003

[Chemical synthesis of biodegradable poly-para-dioxanone and its application for mandibular fracture fixation].

OBJECTIVE: To observe mandibular fracture healing after synthesized bioabsorable poly-para-dioxanone (PDS) ligature fixation. METHODS: Para-dioxanone monomer was prepared by chemical reactions of metallic sodium, ethylene glycol and other raw materials. PDS was synthesized by polymerizing the purified para-dioxanone in the presence of catalyst under the conditions of negative pressure and certain temperature. PDS ligature was obtained by processing the polymer into small granules, drying and melt-extruding through a spinnerette. Eighteen adult male New Zealand rabbits were assigned randomly into two groups. After mandibular fracture models were created, reductions of the artificial fractures were accomplished by means of transosseous PDS ligatures on each of 12 rabbits in experimental group. While the other six rabbits without any internal fixation were set as control. Schedules for killing were arranged to give postoperative samples at two-week interval till 12th week. RESULTS: Radiographical and histological examinations demonstrated that all fractures fixed with PDS ligatures healed without any complication. Periosteal and cartilaginous osteogenesis was observed in newly formed external callus. In contrast, bone fragment migration and the consequent nonunion occurred in the control group. PDS ligature degraded and absorbed without interference with osseous union and healing. The tensile strength reduction of PDS ligature was prior to its absorption in vivo. CONCLUSION: The synthesized PDS is a colorless, flexible, themoplastic and monofilament fiber, which can be sterilized by ethylene oxide embalmment without serious loss of tensile strength. It seems that the application of this macromolecular material in internal fixation is of great worth for further study.

Absorbable Implants↗

PubMed2002

[Advances and prospective application of stem cell technique in stomatology].

In this paper the background and advances of stem cell technique in stomatology were reviewed, especially the lately research of repair of maxillofacial defects with bone marrow stem cells, repair or reconstitution of teeth with dental pulp stem cells and repair of other tissues such as parotid with embryonic stem cell. Stem cell technique provides a new choice and extensive prospect of application for stomatology, therefore, deserves further research.

Oral Medicine↗

PubMed2002

[A clinical study on immediate implantation of particulate hydroxylapatite artificial bone after teeth extraction].

OBJECTIVE: The aim of this study is to investigate the effect and complication of immediate implantation of particulate hydroxylapatite artificial bone after teeth extraction. METHODS: Particulate hydroxylapatite artificial bone was implanted into 65 extraction sockets after teeth extraction. All patients were followed up until 3 months after the operation. They are examined with clinical examination and X-ray examination to observe the effect and complication of the implantation operation. RESULTS: The wound healed well in all cases without any complication. Compared to the alveolar ridge before teeth extraction, and the height of the alveolar ridge after teeth extraction didn't decrease. CONCLUSION: Implantation of particulate hydroxylapatite artificial bone after teeth extraction could maintain the height of the alveolar ridge and reduce the complication of teeth extraction. It would be helpful for the following prosthetic restoration. The immediate implantation of artificial bone is therefore needed further study.

Adult↗

PubMedDate not supplied

Molecular and cellular characterization during chondrogenic differentiation of adipose tissue-derived stromal cells in vitro and cartilage formation in vivo.

Human adipose tissue is a viable source of mesenchymal stem cells (MSCs) with wide differentiation potential for musculoskeletal tissue engineering research. The stem cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and expanded in vitro easily. This study was to determine molecular and cellular characterization of PLA cells during chondrogenic differentiation in vitro and cartilage formation in vivo. When cultured in vitro with chondrogenic medium as monolayers in high density, they could be induced toward the chondrogenic lineages. To determine their ability of cartilage formation in vivo, the induced cells in alginate gel were implanted in nude mice subcutaneously for up to 20 weeks. Histological and immunohistochemical analysis of the induced cells and retrieved specimens from nude mice at various intervals showed obviously cartilaginous phenotype with positive staining of specific extracellular matrix (ECM). Correlatively, results of RT-PCR and Western Blot confirmed the expression of characteristic molecules during chondrogenic differentiation namely collagen type II, SOX9, cartilage oligomeric protein (COMP) and the cartilage-specific proteoglycan aggrecan. Meanwhile, there was low level synthesis of collagen type X and decreasing production of collagen type I during induction in vitro and formation of cartilaginous tissue in vivo. These cells induced to form engineered cartilage can maintain the stable phenotype and indicate no sign of hypertrophy in 20 weeks in vivo, however, when they cultured as monolayers, they showed prehypertrophic alteration in late stage about 10 weeks after induction. Therefore, it is suggested that human adipose tissue may represent a novel plentiful source of multipotential stem cells capable of undergoing chondrogenesis and forming engineered cartilage.

Adipose Tissue↗