Analysis of the mitochondrial mutations of articular chondrocyte in temporomandibular joint osteoarthrosis / 北京大学学报(医学版)

Objective :To explore the significance of mitochondrial DNA mutations of articular chondrocytes in the rat model of temporomandibular joint osteoarthrosis (TMJOA). Methods:TMJOA models were created in left sides of TMJ of 15 SD rats by the partial resection of the articular disc.The experimental rats were killed 3 months after operation. After the chondrocytes culture, the entire mtDNA were amplified using 32 pairs of overlapping. DNA fragments showing different banding patterns between normal and experimental mtDNA by temporal temperature gradient gel electrophoresis were sequenced to identify the mutations. Results: Of the 35 heteroplasmic pattern PCR products, 42 novel mutations were found, Majority of the novel mutations were in the tRNA and D-loop regions. Conclusion:The mutations occurred in the mtDNA of TMJOA articular chondrocytes.

In vitro amplification of immortalized chondrocytes with micro-carriers in RCCS / 第三军医大学学报

Objective To explore the method and technique to gain adequate seed cells for cartilage tissue engineering Methods hTERT gene was introduced into rabbit mandibular condylar chondrocytes by eukaryotic vector Rapidly proliferated immortalized chondrocytes in positive clones in micro carrier rotary cell culture system (RCCS) were screened and selected The growth of immortalized chondrocytes and the metabolic rate were observed Collagen type Ⅱ expression of immortalized chondrocytes of the experimental groups was observed The immunohistochemical results were compared with those of the control groups Results The immortalized chondrocytes in experimental groups could grow rapidly with a high metabolic rate and shorter population doubling time (PD) ( P

Experimental study of the cartilage formation of immortalized chondrocytes in vivo / 第三军医大学学报

Objective To explore the feasibility of the construction and formation of cartilage with immortalized chondrocytes by tissue engineering technology in vitro . Methods Human telomerase reverse transcriptase(hTERT) gene was introduced into rabbit mandibular condylar chondrocytes by eukaryotic vector. After screening with G418, the positive clones were amplified for culture. Normal or immortalized chondrocyte loaded cytoskeleton ? tricalcium phosphate (? TCP) complexes were incubated in vitro for 1～2 d and then implanted into subcutaneous tissue of nude mouse. The complexes of immortalized chondrocyte ? TCP and chondrocyte ? TCP or ? TCP alone were established as the experimental group and control groups respectively. The specimens were harvested within 3 and 6 months after surgical procedure for histological and immunohistochemical observation. Results In experimental groups and control group 1, the complexes packed with cartilage like tissue were found, but there was only a little fiber like tissue formed in control group 2. Immunohistochemistry revealed strong positive staining with safranine O, toluidine blue and collagen type II and obvious formation of cartilage. There was significant difference between the experimental group and the control groups( P

The experimental study on telomerase activity and expression of p53 and c-myc genes in tongue cancer / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study telomerase activity and expression of oncogenes c-myc and p53 in tongue cancer, analyse the interaction among them, and assess their possible correlations with tongue cancer clinicopathological features.</p><p><b>METHODS</b>To detective the telomerase activity by TRAP and examine the positive expression of c-myc and p53 in tongue cancer by hybridization in situ.</p><p><b>RESULTS</b>A high telomerase activity existed in lower differentiated tongue cancer (P < 0.05); the positive expression of c-myc increased significantly in lower grade tongue cancer (P < 0.05) and the positive expression of p53 decreased increasingly in tongue cancer accompanied with lymph node metastasis (P < 0.05).</p><p><b>CONCLUSION</b>Telomerase may play a key role in the tumorigenesis of tongue cancer. Meantime, c-myc and p53 exerts important effect on telomerase activation during the course of tongue cancer generation and development.</p>

Changes of astrocytes and apoptosis of neurons in facial nerve nucleus after facial nerve transection in rats / 第三军医大学学报

Objective To observe the changes of astrocytes and expressions of bcl 2 and bax in neuron apoptosis in facial nerve nucleus after facial nerve transection in rats Methods A total of 72 rats were equally divided into normal control, and facial neurotmesis groups. Six rats were killed 3,7,15,21,30 and 60 d after transection respectively and same amount of rats were killed in same time interval in the control group. Brain samples were taken from the aboue mentioned rats and the facial neuron apoptosis was detected with TUNEL, and expressions of bcl 2 and bax and changes of GFAP in the astrocytes of facial nerve nucleus were studied with immunohistochemical methods and image analyses separately Results The apoptotic peak of facial neurons and remarkable expression of bcl 2 and bax appeared in 15 d after the facial neurotmesis, while the expression ratio of bcl 2/bax were the lowest Meantime, the reaction of the astrocytes(GFAP)was remarkable, too All the changes were statisfically significantly compared with the control groups ( P