Expression of Notch signaling pathway during osteoarthritis in the temporomandibular joint.

PURPOSE: Our study aim was to characterize the expression of Notch molecules during temporomandibular joint osteoarthritis (TMJOA), thus exploring the mechanism and roles that Notch signaling possibly plays in the initiation and progression of TMJOA. MATERIALS AND METHODS: A total of 126 mice were divided randomly into experimental groups, a sham-surgery group and a normal control group. In the experimental group, total discectomy was performed in the right temporomandibular joint (TMJ) to induce TMJOA; the sham-operation group underwent the same procedure without disc removal, and the normal control group was left undisturbed. Fourteen mice in each group were sacrificed in batches respectively at 1, 2, and 4 weeks postoperatively. Histology was performed to examine TMJOA in eight condyles each group, and a modified Mankin scoring system was used for evaluation. Immunohistochemistry was carried out to characterize the expression of the Notch markers Notch1, Jagged1, Hes1, and Hes5. Real-time polymerase chain reaction (RT-PCR) was performed for further detection and analysis of Notch markers in six condyles in each group. RESULTS: Notch1, Jagged1, and Hes5 were activated in the experimental group, with expression levels that increased dramatically over time, whereas the control group showed no fluctuation. Hes1 expression was suppressed at the beginning but was up-regulated afterward. CONCLUSIONS: Our data suggest that Notch signaling is activated in TMJOA with a much more abundant expression in osteoarthritis cartilage.

Expression of Notch signaling pathway in temporomandibular osteoarthritis / 口腔疾病防治

Objective@# To investigate the expression of Notch signaling molecules in temporomandibular joint arthritis (TMJOA), and to explore the role and mechanism of Notch signaling pathway in the development and progression of TMJOA. @*Methods @#72 Kunming mice were randomly divided into experimental group, sham-surgery group and normal group. In experimental group, discs on the right TMJ were subjected to total discectomy, sham-operation group underwent the same procedure without disc removal, while normal group serve as blank control. All the left temporomandibular joint discs were not treated. 8 mice in each group were sacrificed respectively at 1 week, 2 week, 4 week after surgery. Histological examinations were performed to assess success of TMJOA model, according to the pathological standard of osteoarthritis diagnosis. Immunochemistry techniques were performed in the successful TMJOA cartilages to evaluate the expression levels of Notch1 (NICD1), Jagged1, Hes1 and Hes5. The scores were evaluated by semi-quantitative method. @*Results @#Notch1 (NICD1), Jagged1 and Hes5 were activated in the experimental group with the expression levels increased dramatically over time. While Hes1 expression was suppressed at the beginning of osteoarthritis but was up-regulated afterwards.@*Conclusion @# Notch pathway-related molecular expression changed greatly in TMJOA model, indicating that the pathway in the occurrence and development of TMJOA plays an important role.

Effect of early intra-articular injection of alendronate in reducing subchondral bone loss in rat mandibular condyle after ovariectomy / 口腔疾病防治

Objective @#To investigate the effects of intra-articular injection of alendronate on the mandibular condyle in ovariectomized rats.@*Methods @#Sixty female rats were randomly divided into five groups: ovariectomy with vehicle treatment alone, early alendronate treatment at ovariectomy, late alendronate treatment at 4 weeks after ovariectomy, shamoperation with vehicle treatment, and the normal control rats. The changes in subchondral bone were evaluated by micro-computed tomography (Micro-CT), tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative polymerase chain reaction (RT-PCR). @*Results @# Compared with late alendronate treatment, early alendronate treatment improved microstructural properties of the subchondral bone, with higher bone volume ratio (46.4 + 2.5 vs 37.5 + 2.1; P= 0.038), increased trabecular thickness (47.3 + 1.7 vs 34.6 + 1.4; P = 0.029), elevated trabecular number (8.5 + 0.6 vs 6.2 + 0.3; P = 0.041) and lower trabecular separation (30.2 + 1.6 vs 37.7 + 2.6; P = 0.034). Fewer TRAP-positive cells (4.2 + 0.2 vs 6.8 + 0.4; P = 0.019) and a higher OPG/RANKL ratio (0.38 + 0.01 vs 0.25 + 0.03; P = 0.043) in the subchondral bone were observed in the animals with early treatment group compared to late treatment or ovariectomy/vehicle treatment group. @*Conclusion @#Our results suggest the therapeutic potential of intra-articular alendronate injection in the treatment of osteoporosis-associated temporomandibular disorders.

The effect of oxytocin on osseointegration of titanium implant in ovariectomized rats.

INTRODUCTION: Oxytocin (OT) was reported to control differentiation of human mesenchymal stem cells and reverse osteoporosis (OP). This study investigated the effect of systematical treatment of OT on implant osseointegration in ovariectomized (OVX) rats. MATERIAL AND METHODS: Twenty female rats received bilateral ovariectomy. Twelve weeks later, all animals were randomly assigned to control or experimental group. Each rat received two implants at the distal femoral metaphysis. From the first postoperative day, rats in experiment group received subcutaneous injection of OT (1 mg/kg · d), while animals in control group received vehicle. Twelve weeks after implantation, specimens containing implants were harvested and evaluated by histology, micro-CT, and push-out test. Tibiae were also harvested to evaluate the effect of OT on intact bone tissue of OVX rats. RESULTS: Compared with control, OT treatment increased the relative bone volume surrounding the implant by 2.2 times, the percent implant osseointegration by 0.62 times, and the maximum push-out force by 2.25 times. Increased bone mass was also observed in histological sections of distal femur with implant and intact bone tissue of the proximal tibiae. CONCLUSION: Systemic administration of OT promoted peri-implant bone healing and osseointegration of titanium implant and recovered the negative effects of OP in undisturbed bone tissue partially.

[Clinical values and optimal cut-off points of basic vital signs in early identification of critical hand, foot, and mouth disease].

OBJECTIVE: To study the clinical values of basic vital signs in early identification of critical hand-foot-mouth disease (HFMD). METHODS: The clinical data of 358 children with severe HFMD [212 cases in stage 2 (central nervous system involvement) and 146 cases in stage 3 (earlier stage of cardiopulmonary failure, critical type)] were reviewed. The diagnostic values of peak temperature and duration of fever, as well as the heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) in different age groups, for critical HFMD (stage 3) were analyzed using the receiver operating characteristic (ROC) curve. RESULTS: HFMD might progress to critical type in case of HR≥148.5 beats/minutes, RR≥36.5 times/minutes, SBP≥95 mm Hg, and DBP≥59 mm Hg among children aged 0-1 year. HR≥142.5 times/minutes, RR≥31.5 times/mintes, SBP≥103 mm Hg, and DBP≥60.5 mm Hg in children aged 1-2 years had a certain diagnostic value for critical HFMD. HFMD might progress to critical type in case of HR≥139.5 times/minutes, RR≥29.5 times/minutes, and SBP≥103 mm Hg among children≥3 years of age. The sensitivity and specificity of every indicator were higher than 0.517 and 0.769, respectively. The area under the ROC curve (AUC) for peak temperature was 0.507 (P=0.816, compared with AUC=0.5). When the duration of fever was ≥5.5 days, the sensitivity and specificity were 0.589 and 0.571, respectively. CONCLUSIONS: HR, RR, and BP are good indicators to identify critical HFMD (stage 3) early. The optimal cut-off points conform to the age characteristics of children. DBP in children≥3 years of age, peak temperature, and duration of fever have a low value in early identification of critical HFMD.