Screening of the gene mutation in D-loop region of mitochondrial DNA in oral squamous cell carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the gene mutation in D-loop region of mitochondrial DNA (mtDNA) in oral squamous cell carcinoma (OSCC) tissue and to explore the role of the gene mutation in D-loop region in the OSCC tumorigenesis.</p><p><b>METHODS</b>mtDNA was obtained from cancer, paracancerous and normal mucosa tissues of thirty patients with OSCC. The D-loop regions of mtDNA were amplified with PCR, sequencing and then analyzed by Chromas software and BLAST to identify the mutation site.</p><p><b>RESULTS</b>Mutation in the D-loop region was found in eight cases, with the mutation rate of 27%. There were nine mutations totally, including one point mutation, two base deletions, three insertion mutations, three heterozygous mutations. In these mutations, base deletions were different from each other and heterozygous mutations had no same mutation form, while the three insertion mutations were same, the insertion of base C. One case had T/A heterozygous mutation and base C insertion at the same time.</p><p><b>CONCLUSIONS</b>There were mutations in mtDNA D-loop in OSCC, but the relationship between occurrence of OSCC and mutation of mtDNA needs further study.</p>

Construction of tissue engineering bone with bone marrow stromal cell sheets / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To construct tissue engineering bone with bone marrow stromal cell (BMSC) sheets of dogs.</p><p><b>METHODS</b>BMSC were derived from dog bone marrow and cell sheets were prepared with temperature-responsive dishes after the cells were induced by osteogenesis. Allogeneic dogs decalcification bone matrixes (DBM) were prepared. Sixteen dogs were divided into 4 groups. The MSC cell sheets-rhBMP-2-BMSC-DBM were implanted under the left latissimus dorsi myofascial as the experimental side; while the rhBMP-2-BMSC-DBM were implanted in the right side as the control. Ectopic bone formation in vivo was evaluated by histological examination 4, 8, 12, 16 weeks after operation.</p><p><b>RESULTS</b>The osteogenesis in the experimental group was better than that in the control group. New bone area in the experimental side was larger than that in the control group, and the difference was significant (P < 0.05). After 16 weeks, lamellar bone was connected into a film in the experimental group. Haversian system and red bone marrow could be seen.</p><p><b>CONCLUSIONS</b>BMSC cell sheets could promote the bone formation of functional tissue-engineered bone.</p>

The mutations of the D-loop hypervariable region II and hypervariable region III of mitochondrial DNA in oral squamous cell carcinoma / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the frequency of mitochondrial DNA (mtDNA) D-loop hypervariable region II (HVR II) and hypervariable region III (HVR III) mutations in oral squamous cell carcinoma (OSCC) and their correlation to provide the new targets for the prevention and treatment of OSCC.</p><p><b>METHODS</b>The D-loop HVR II and HVR III regions of mtDNA in seven cases with OSCC tissues, matched with paracancerous tissues and normal mucosa tissues from the same case, were amplified by polymerase chain raction (PCR), then were detected by direct sequencing to find the mutantsites after the comparison of all sequencing results with the mtDNA Cambridge sequence in the GenBank database.</p><p><b>RESULTS</b>82 (56 species) nucleotide changes, with 51(26 species) nucleotide polymorphism, were found after the comparison of all sequencing results with the mtDNA Cambridge sequence in the GenBank database. 31(30 species) mutations, with 21 located within the HVR II and HVR III regions, were found in 3 tumor tissue samples, their paracancerous and normal mucosa tissue were found more polymorphic changes but no mutation. The mtDNA D-loop HVR II and HVR III regions mutation rate was 42.9% (3/7) in OSCC.</p><p><b>CONCLUSION</b>The mtDNA D-loop HVR II and HVR III regions were highly polymorphic and mutable regions in OSCC. It suggested that the D-loop HVR II and HVR III regions of mtDNA might play a significant role in the tumorigenesis of OSCC. It may become new targets for the gene therapy of OSCC by regulating the above indexes.</p>

Measurement of mandible bone mineral density of adults in north China / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To measure the bone mineral density (BMD) of mandible and investigate the relationship between mandible and the whole body skeleton BMD.</p><p><b>METHODS</b>Healthy volunteers were recruited in north China, which were divided into 6 groups by age: > or = 20, > or = 30, > or = 40, > or = 50, > or = 60 and > or = 70 years older, 10 male and 10 female in each group. Dual-energy X-ray absoptiometery (DXA) was used to measure the BMD of the lumbar spine, the mentum of mandible and the mandibular angle. The results were analyzed statistically.</p><p><b>RESULTS</b>The mineral density (MD) of the mentum was (1.310 9 +/- 0.035 5) g/cm2, the left mandibular angle (1.048 9 +/- 0.013 7) g/cm2, the right mandibular angle (1.0547 +/- 0.014 1) g/cm2, the lumbar spine (L2-L4) (1.121 1 +/- 0.017 2) g/cm2. There was a significant difference in mandibular angle and lumbar MD between men and women (P < 0.05). The MD of mandibular angle and lumbar spine decreased significantly after 50 years of age.</p><p><b>CONCLUSIONS</b>The normal BMD of the mandibular mentum, mandibular angles and lumbar spine is obtained. The BMD of the mandibular angles is closely related to that of the lumbar spine. Mandible can be an appropriate measurement site in the evaluation of skeleton BMD status for the forecast of osteoporosis.</p>

Maxillary sinus lifting and simultaneously placement of implants from the top of alveoli / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the effect of maxillary sinus floor elevation by the Frialit-2 Bone Condenser for implantation.</p><p><b>METHODS</b>11 patients underwent sinus floor lift by The Frialit-2 Bone Condenser and were inserted 14 implants. The time of following up was 10 - 21 months.</p><p><b>RESULTS</b>There were no implant loose or lost, no clinical complaint of maxillary sinus area, and X-ray exam showed well osseointegration.</p><p><b>CONCLUSIONS</b>The Frialit-2 bone condenser can be used for lifting sinus floor, and the sinus elevation without lateral access allows the insertion of implants with no additional surgical stress for the patients.</p>