BACKGROUND:Bone remodeling is the biological basis of orthodontic tooth movement.Type 2 diabetes mellitus leads to metabolic changes in the jaw and alveolar bone,so it is hypothesized that tooth mobility characteristics may be altered in a high-sugar environment.OBJECTIVE:To explore the impact of type 2 diabetes mellitus on orthodontic tooth movement in rats within one tooth movement cycle.METHODS:Seventy-two Sprague-Dawley rats were selected.Forty rats were randomly chosen and fed with a high-fat diet to construct a type 2 diabetes mellitus model.Thirty-two rats that were successfully modeled were randomly divided into a type 2 diabetes mellitus group(n=16)and a diabetic orthodontic group(n=16).The remaining 32 rats were randomly divided into a control group(n=16)and an orthodontic group(n=16).The rats in the orthodontic group and the diabetic orthodontic group were equipped with nickel-titanium coil spring orthodontic force application devices to move the unilateral maxillary first molars mesially with a force of 50 g.The rats were anesthetized and sacrificed on the 3rd,7th,14th,and 21st days after orthodontic treatment,and Micro-CT was used to measure the mesial displacement of the first molars and detect the changes in the bone microstructure parameters on the tension side.RESULTS AND CONCLUSION:There were significant differences in the tooth movement distances among the four groups of rats on the 3rd,7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were significant differences in bone mineral density,bone volume fraction and trabecular bone separation on the tension side among the four groups on the 7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were differences in the trabecular thickness among the four groups on the 3rd and 14th days of orthodontic treatment(P＜0.05).The diabetic orthodontic group had the smallest tension-side alveolar bone mineral density,bone volume fraction,and trabecular thickness,and the largest tooth movement distance and trabecular separation on the 21st day of orthodontic treatment.The above results indicate that type 2 diabetes mellitus adversely affects bone microstructural parameters on the tension side in orthodontic tooth movement in rats,suggesting the occurrence of an osteoporotic state.

BACKGROUND:Bone remodeling is the biological basis of orthodontic tooth movement.Type 2 diabetes mellitus leads to metabolic changes in the jaw and alveolar bone,so it is hypothesized that tooth mobility characteristics may be altered in a high-sugar environment.OBJECTIVE:To explore the impact of type 2 diabetes mellitus on orthodontic tooth movement in rats within one tooth movement cycle.METHODS:Seventy-two Sprague-Dawley rats were selected.Forty rats were randomly chosen and fed with a high-fat diet to construct a type 2 diabetes mellitus model.Thirty-two rats that were successfully modeled were randomly divided into a type 2 diabetes mellitus group(n=16)and a diabetic orthodontic group(n=16).The remaining 32 rats were randomly divided into a control group(n=16)and an orthodontic group(n=16).The rats in the orthodontic group and the diabetic orthodontic group were equipped with nickel-titanium coil spring orthodontic force application devices to move the unilateral maxillary first molars mesially with a force of 50 g.The rats were anesthetized and sacrificed on the 3rd,7th,14th,and 21st days after orthodontic treatment,and Micro-CT was used to measure the mesial displacement of the first molars and detect the changes in the bone microstructure parameters on the tension side.RESULTS AND CONCLUSION:There were significant differences in the tooth movement distances among the four groups of rats on the 3rd,7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were significant differences in bone mineral density,bone volume fraction and trabecular bone separation on the tension side among the four groups on the 7th,14th,and 21st days of orthodontic treatment(P＜0.05).There were differences in the trabecular thickness among the four groups on the 3rd and 14th days of orthodontic treatment(P＜0.05).The diabetic orthodontic group had the smallest tension-side alveolar bone mineral density,bone volume fraction,and trabecular thickness,and the largest tooth movement distance and trabecular separation on the 21st day of orthodontic treatment.The above results indicate that type 2 diabetes mellitus adversely affects bone microstructural parameters on the tension side in orthodontic tooth movement in rats,suggesting the occurrence of an osteoporotic state.

OBJECTIVE To study active components and antitussive effect of aboveground part of Pinellia ternata （non- medicinal stems and leaves）， and compare them with the underground part of P. ternata （medicinal underground tubers）， providing scientific basis for the comprehensive utilization and product development of P. ternata. METHODS TLC， GC， HPLC and UPLC- MS/MS were used for qualitative and quantitative analysis of amino acids， volatile oil， total flavonoids and succinic acid from the aboveground and underground parts of P. ternata. The antitussive effects of the aboveground and underground parts of P. ternata were compared and studied through cough inducing experiment with concentrated ammonia water. RESULTS Results of TLC showed that at the corresponding positions on the chromatograms of the reference substances of P. ternata， and arginine， alanine， valine， leucine and rutin control， the aboveground and underground parts of P. ternata showed spots of the same color. Results of GC showed that the similarity among characteristic chromatograms of volatile oil from aboveground and underground parts of P. ternata was 0.767； results of HPLC and UPLC-MS/MS showed that compared with underground parts of P. ternata， the contents of succinic acid， quercetin， kaempferol and isorhamnetin increased by 0.15%， 0.15%， 0.09% and 0.03%， and aspartate content decreased by 2.5 mg/g. Pharmacodynamics results showed that compared with model control group， the cough incubation period of rats was prolonged significantly in administration groups （P＜0.05）， and the cough frequency within 3 min was significantly decreased （P＜0.05）； there was no statistical significance in the cough frequency within 3 min among administration groups （P＞0.05）. CONCLUSIONS The composition of amino acids， volatile oils and total flavonoids in aboveground part of P. ternata are similar to underground part of P. ternata， while the content of aspartic acid is lower than that in underground part. The aboveground part of P. ternata can prolong the cough incubation period of rats and reduce the number of coughs， which has a certain antitussive effect， but the effect is slightly weaker than that of the underground part.

Objective To investigate the distribution rules of setup errors in different locations for tomotherapy.Methods 151 patients induding 53 head and neck tumors,45 thoracic tumors,20 abdominal tumors,and 33 pelvic tumors,who accepted tomotherapy were retrospectively analyzed in this study.The planning CT images of patients were obtained in simulation,and all patients underwent megavoltage CT (MVCT) scan before radiotherapy.And the setup errors were calculated by rigid registering MVCT images to planning CT images,and setup errors on + x(left),-x(right),+ y(in),-y(out),+z(ventral),-z (dorsal)axes were analyzed respectively.Results A total of 3 281 MVCT scans were performed on 151 patients,The setup errors on +x (left),-x(right),+y(in),-y(out),+z (ventral),-z (dorsal)axes were (1.61 ± 1.21),(1.76 ±2.11),(2.26 ± 1.74),(1.83 ± 1.47),(3.24±1.76) and (1.75 ± 1.61)mm for head and neck tumors;(2.43 ±1.88),(2.55 ± 1.92),(3.06 ±2.64),(3.90 ±2.91),(6.71 ±3.46) and (2.64 ±2.77)mm for thoracic tumors;(3.67±3.06),(2.37±1.77),(3.18±1.96),(3.98±3.01),(6.74±3.25) and (1.92±2.00) mm for abdominal tumors;(2.92 ±2.13),(2.17±1.68),(3.50±2.61),(3.72±2.66),(7.18± 3.43) and (1.92 ± 1.61)mm for pelvic tumors,respectively.The setup errors were different between +z and-z with statistically significant in all tumors (t =-4.119、-5.033、-3.763、-5.057,P ＜ 0.05).The setup errors on + z direction of patients immobilized with thermoplastic mask were smaller than those immobilized with vacuum cushions for thoracic tumors (t =-2.357,P ＜ 0.05).Conclusions The setup errors of head and neck tumors are less than other parts tumor in tomotherapy.The patients immobilized with thermoplastic mask can reduce the setup errors for thoracic tumors.The heterogeneity of setup errors on ventral-dorsal directions for the all parts of tumors should not be ignored.

Objective To study the feasibility of helical tomoterapy (HT) at prescription dose escalation for nasopharyngeal carcinoma (NPC).Methods Static-IMRT (sIMRT) and HT plans were designed for 10 nasopharyngeal carcinoma patients which were treated by sIMRT and HT treatment plan.Prescription dose was escalated for each plan until any organs at risk (OARs) reached the quantitative analysis of normal tissue effects within the clinical threshold.Dosimetric factors of target and OARs were analyzed for both sIMRT and HT plans.Results Compared with sIMRT plan, prescribed dose of HT plans increased 42.6％ (t =6.373, P ＜ 0.01), and the homogeneity index was also improved (t =-2.288, P＜0.05);the conformity index decreased (P ＞ 0.05).The limits of HT prescribed dose escalation were spinal cord (2 cases), optic nerve (5 cases) and brainstem (3 cases).The limits of sIMRT prescribed dose escalation were lens (1 case), spinal cord (1 case) and parotid (8 cases).Conclusions HT could improve prescription dose of nasopharyngeal carcinoma while keeping the OARs safe.Compared with sIMRT, HT technology might be used at high dose NPC radiotherapy.