ABSTRACT
BACKGROUND: Lingual bracket system is the best invisible orthodontic appliance due to its aesthetics and efficiency, but it is difficult to control anterior tooth torque during the distal retraction of the anterior tooth. Thereafter, lots of studies on maxillary anterior teeth have been conducted, but there is less knowledge about the mechanical characteristics of whole mandible dentition distal retaction. OBJECTIVE: To analyze the biomechanical characteristics of the mandibular anterior teeth distal retracted by sliding method in lingual orthodontic treatment. METHODS: A three-dimensional finite element model was constructed using a series of specialized software based on volunteer's CT data and lingual brackets, including the mandible, alveolar bone, periodontal ligament, dentition (removal of the two first premolars), lingual brackets and arch wire with hooks (located between lateral incisor and canine and 11 mm distant from the arch wire plane). Subsequently, 1.5 N lingual forces through the hooks of first molar (2 mm distant from the arch wire plane) and the hooks between the lower lateral incisor and canine were loaded and the biomechanical characteristics of the mandibular anterior teeth movement during the en-masse retraction were analyzed. RESULTS AND CONCLUSION: The finite element model was constructed successfully, and had a higher geometrical similarity and resemblance of clinical situation. The crowns of lower incisors showed the tendency of lingual inclination and extension, and this tendency was more obvious in the lateral incisors. The canines were buccal and mesial inclination and intrusion. The periodontal stress concentration area was corresponded with the tendency of tooth movement. Therefore, the movement tendency of incisors is still lingual inclination when mandibular anterior teeth distal retracted by a longer hook in lingual brackets system, and there is no distal inclination. Overall, lower incisors are easy to exhibit lingual inclination; the long anterior hooks contribute to the movement of canines, but it is not available for the vertical control of incisors during mandibular anterior tooth distal retraction.
ABSTRACT
@#Objective: To explore the expression of long non-coding RNA RP11-259P1.1 (lncRNA RP11-259P1.1) in small cell lung cancer (SCLC) tissues and to analyze the relationship between lncRNARP11-259P1.1 expression and SCLC clinicopathological characteristics, as well as to investigate its effect in chemoresistance. Methods: Tissue samples, including 158 cases of tumor tissues from SCLC patients, who underwent bronchoscopic biopsy, puncture biopsy and surgical resection, 48 cases of para-cancerous tissues and 40 cases of normal lung tissues, collected from January 2012 to December 2016 in the Sixth People’s Hospital of Chengdu and General Hospital of Chengdu Military Region，were used in this study. The expression of lncRNARP11-259P1.1 was detected by Real-time fluorescence quantitative PCR (qPCR). χ2 test was used to analyze the relationship between the expression of lncRNA RP11-259P1.1 and the clinicopathological characteristics as well as chemotherapeutic resistance in SCLC patients. Relationship between lncRNA RP11259P1.1 expression and prognosis of SCLC patients was analyzed by univariate and multivariate Cox regression analysis. Results: The expression of lncRNA RP11-259P1.1 in SCLC tissues was significantly higher than that in para-cancerous tissues and normal lung tissues (all P < 0.01). The expression of lncRNA RP11-259P1.1 in cancer tissues of chemosensitive group was significantly lower than that of chemoresistant group (P<0.05). The expression of lncRNA RP11-259P 1.1 was not correlated with gender and age, but significantly correlated with tumor stage, metastasis and chemosensitivity (all P<0.05). PFS and OS in patients with high lncRNA RP11-259P 1.1 expression were significantly shorter than those in patients with low expression ([12.25±1.83] vs [22.29±1.58] months, [23.55±1.35] vs [31.75±2.43] months, all P<0.01). The expression of lncRNA RP11-259P 1.1, tumor stage and distant metastasis were the independent prognostic factors in SCLC patients (all P<0.05). Conclusion: The high expression of lncRNA RP11-259P1.1 in SCLC tissues is associated with chemosensitivity and prognosis of SCLC patients, and may be a potential biomarker for prognosis evaluation in SCLC patients.
ABSTRACT
Aim The relative bioavailability of domestic ibudilast sustained release capsules in healthy volunteers was observed.Methods A single oral dose of 20 mg of imported and domestic ibudilast sustained release capsules and 10 mg of ibudilast raw material was separately given to 12 healthy volunteers in a randomized crossover study. Ibudilast concentration in plasma was determined by HPLC method.Results The Cmax were (54.9?9.7),(60.7?9.1) and (62.2?11.5) ?g?L-1; the tmax were (3.8?0.8),(3.9?0.8) and (1.8?0.3) h;the t1/2(ke) were (1.5?1.4),(12.1?1.0) and (3.5?0.5) h,and the AUC(0～t) were (618.1?57.7),(588.1?66.6) and (233.0?46.4) ?g?h?L-1 in imported capsule group, domestic capsule group and raw material group respectively. The relative bioavailability of domestic sustained release capsules of ibudilast is (95.6?11.0)%. Conclusion The results of statistical analysis demonstrate that the imported and domestic sustained capsules have significant character of significantly sustained release and are bioequivalent.