Combined use of 1,25-dihydroxyvitamin D3 and dexamethasone promotes osteogenic differentiation of synovial fluid mesenchymal stem cells from human temporomandibular joint / 中国组织工程研究

BACKGROUND:Synovial fluid mesenchymal stem cells can be amplified rapidly in vitro and collected by a minimally invasive method. Recent studies have suggested that synovial fluid mesenchymal stem cells have become an important kind of seed cells for bone tissue engineering. Osteogenic differentiation is required to be optimized prior to the application of synovial fluid mesenchymal stem cells in the bone regeneration. OBJECTIVE: To describe a protocol to generate osteoblast-lineage cells from human synovial fluid mesenchymal stem cells of the temporomandibular joint using a cocktail that includes glutamax, dexamethasone, β-glycerophosphate, vitamin C, 1,25-dihydroxyvitamin D3, and to investigate the effect of 1,25-dihydroxyvitamin D3 and dexamethasone on the osteogenic capacity of synovial fluid mesenchymal stem cells. METHODS:Synovial fluid mesenchymal stem cells from the human temporomandibular joint were expanded in vitro and cultured in different osteogenic induction media. The mineralization capacity of osteogenic differentiation was evaluated by alizarin red and Von kossa staining. And the osteogenic markers, including ALP, RUNX2 and OCN, were assessed by reverse transcription-PCR. RESULTS AND CONCLUSION: The mineralization formation increased greatly in the medium with 100 nmol/L dexamethasone and 10 nmol/L 1,25-dihydroxyvitamin D3. The expression of ALP, RUNX2 and OCN was enhanced distinctly in the 1,25-dihydroxyvitamin D3-induced differentiated cells. These findings reveal that appropriate concentration of 1,25-dihydroxyvitamin D3 and dexamethasone can be ideal ingredients to induce the osteogenic differentiation of human synovial fluid mesenchymal stem cells of the temporomandibular joint. Thus, this effective condition can be used to induce the osteogenic differentiation of synovial fluid mesenchymal stem cells for the bone regeneration in the temporomandibular joint.

New bone and cartilage tissues formed from human bone marrow mesenchymal stem cells derived from human condyle in vivo / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the ability to form new bone and cartilage tissues of bone marrow mesenchymal stem cells (BMSC) derived from human condyle in vivo, to search the new source of seed cells in constructing tissue engineering condyle.</p><p><b>METHODS</b>Bone marrow was collected from the irrigation solution from resected human condyle, and was isolated by density gradient centrifugation and then purified by adherent separation and cultured in vitro. P3 or P4 BMSC populations were induced into osteoblasts and chondroblast under inductive medium in vitro and then seeded on porous coral scaffolds. The appearance and affinity of cells were investigated via scanning electron microscope. And then osteoblast or chondroblast/coral scaffolds composites were implanted into the dorsum of nude mice. The mice were sacrificed by anaesthesia overdose at six and nine weeks after surgery and the scaffolds were removed for analysis.</p><p><b>RESULTS</b>Scanning electron microscope showed that BMSC were adhering to the surface of coral and having an overlapped growth or to contact each other as net and stride over the pores. The in vivo scaffold specimens maintained the initial shape of the coral scaffold. The new formed bone tissues were clearly evident and islands of cartilage tissues were also found at nine weeks after implantation.</p><p><b>CONCLUSIONS</b>These BMSC derived from human condyle possess the ability of forming bone and cartilage tissues when being implanted in vivo, and can be used as a kind of seed cells in constructing tissue engineering condyle.</p>

Measurement and analysis of the intra-articular pressure in temporomandibular joint with sudden-onset, severe closed lock / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The study aims to find out the fluctuating curve of the intra-articular pressure in temporomandibular joint with sudden-onset, persistent, severe closed lock and discuss the mechanism of its formation. We also investigate the effects of the arthrocentesis.</p><p><b>METHODS</b>20 affected sides in 16 patients were collected. A No. 8 syringe needle was used to pierce into the upper compartment of TMJ. The pre-arthrocentesis intra-articular pressure was measured by the pressure transducer via the flexural rigid tubing at open and close bite. The curve and mean value were documented during the operation.</p><p><b>RESULTS</b>The patients with sudden-onset, persistent, severe closed lock had significantly low negative intra-articular pressure in their affected temporomandible joints. The average pressures was (-9.947 +/- 8.854) kPa at open bite and (-6.475 +/- 4.147) kPa at close bite.</p><p><b>CONCLUSION</b>The TMJs with sudden-onset, persistene, severe closed lock has particular characters on etiology and clinical behavior. Arthrocentesis is one of the effective treatments to the diseases.</p>

Maxilla reconstruction with the free iliac osteomuscular flap and simultaneous osseointegrated implant embeding / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical outcome of reconstruction of maxillary defects with vascularized iliac crest flap and simultaneous osseointegrated implant embedding.</p><p><b>METHODS</b>During September to October 2003, two patients with maxillary defects from tumor resection underwent microsurgical reconstruction. The free iliac osteomuscular flap transferring and simultaneous osseointegrated implant embedding were performed to repair the defects. Three months after the reconstructive surgery, an abutment operation was preformed and denture was applied in both cases.</p><p><b>RESULTS</b>The flaps survived well. Postoperative follow-up for 8 to 9 months showed that the patients obtained good zygomaxillary appearance, normal occlusion, and satisfactory pronunciation, without oronasal fistula or other serious complications.</p><p><b>CONCLUSIONS</b>The free iliac crest osteomuscular flap with simultaneous osseointegrated implant embedding is an ideal, effective and cosmetically acceptable method for maxilla reconstruction.</p>