ABSTRACT
Objective@#To investigate the effect of parathyroid hormone (PTH) on the bone healing of mandibular ramus osteotomy.@*Methods@#The mandibular ramus osteotomy model was established in sixty rabbits and these rabbits were randomly divided into experimental group A, experimental group B and control group. In the experimental group A and experimental group B, the rabbits were given PTH (20 and 40 μg/kg respectively) every other day after operation. In the control group, 1 ml saline was given. The animals were sacrificed at 1 week, 2 weeks, 3 weeks and 4 weeks postoperatively. The new bone formation was observed by histology and cone bone CT. The expression of osteoprotegerin and receptor activator of nuclear factor kappa-B (RANKL) in the new bone was detected by real-time quantitative PCR.@*Results@#The experimental groups has better osteogenesis and the bone mineral density than the control group in osteotomy area. The experimental group B showed the best osteogenesis.Osteoprotegerin mRNA expression in experimental group A (1.127±0.035, 1.742±0.049, 1.049±0.062, 1.063±0.036) was significantly higher than that in the control group in each period (0.965±0.082, 1.254±0.071, 0.793±0.061, 0.684±0.055) (P=0.010, P=0.000, P=0.001, P=0.020), while group B (1.416±0.205, 2.648±0.168, 1.652±0.091, 1.712±0.070) was significantly higher than group A (P=0.000, P=0.010, P=0.023, P=0.003). RANKL mRNA expression in control group (1.666±0.086, 1.058±0.105, 0.885±0.124, 0.972±0.136) was significantly higher than that of the group A (0.788±0.036, 0.585±0.017, 0.692±0.017, 0.527±0.051) (P=0.001, P=0.006, P=0.003, P=0.028) in each period, while group A was significantly higher than group B(0.247±0.022, 0.240±0.034, 0.134±0.011, 0.103±0.050) (P=0.000, P=0.001, P=0.002, P=0.012).@*Conclusions@#PTH can upregulate the expression of osteoprotegerin and reduce expression of RANKL, thus promoting new bone formation. Intermittent administration of high dose of parathyroid hormone can further promote the healing process after mandibular ramus osteotomy.
ABSTRACT
<p><b>OBJECTIVE</b>This research aimed to investigate the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mandibular distraction osteogenesis (DO) regulated by parathyroid hormone (PTH) and to explore the mechanism by which PTH promotes DO.</p><p><b>METHODS</b>A rabbit mandibular DO model was established. The rabbits were randomly divided into experimental group and control group. The former were subcutaneously injected with different doses of PTH on alternate days, the latter was injected with normal saline every other day. Serum OPG levels were detected through enzyme-linked immunosorbent assay. The OPG and RANKL expression levels in the DO-induced formation of a new bone tissue were examined through immunohistochemistry staining.</p><p><b>RESULTS</b>The serum OPG levels gradually increased during distraction. At the end of the stretch, the OPG expression in the experimental group was significantly stronger than that in the control group. As the fixed period was extended, the OPG expression in the new bone gradually decreased, but the RANKL expression increased.</p><p><b>CONCLUSION</b>Intermittent subcutaneous PTH injection can upregulate the OPG expression and accelerate bone metabolism. Thus, this procedure promotes the early generation of a new bone in the mandible through DO.</p>
Subject(s)
Animals , Rabbits , Enzyme-Linked Immunosorbent Assay , Mandible , NF-kappa B , Metabolism , Osteogenesis, Distraction , Methods , Osteoprotegerin , Metabolism , Parathyroid Hormone , Metabolism , RANK Ligand , Metabolism , RNA, Messenger , Random AllocationABSTRACT
Background To explore the relationship between polymorphism of APOE gene in traumatic brain injury(TBI)patients suffering from traffic accident and the outcome of TBI.Methods TBI patients were randomly selected in this study with caxe-wntrol trial. The genotype of APOE allele was tested by a polymerase chain reaction-restriction fragment length polymorphism ( PCR-RFLP), and the association between different genotypes of APOE alleles and outcome of TBI patients, were analyed.Results In TBI group frequency of APOE ε2 allele was 0. 1010, and frequency of APOE ε2/ε3 was 0. 1596.Both of these results were significantly higher than that in normal people (APOE epsilon 2 was 0. 0050, APOE ε2/ε3 was 0. 0100) (P＜0.05). Frequency of APOE ε2 and APOE ε2/ε3 in TBI group who died was 0. 1970 and 0. 2727. These were significantly high compared to TBI patients who had good recovery.Conclusions APOE allele ε2 and APOE genotype ε2/ε3alleles indicate a poor prognosis of traumatic brain injury patients.