RESUMEN
The dynamic changes of the microstructure of alveolar bone during orthodontic tooth movement in rats was explored by employing micro-computed tomography (micro-CT) system and to provide theoretical reference for clinical orthodontic treatment. Ten rats were selected randomly as control among 70 adult female Wistar rats, and the other 60 rats were divided into 25-g and 75-g groups of equal number. Orthodontic appliance with force of 25 g and 75 g was installed to perform the molar mesial movement. Microstructural parameters for trabecular bone mesial to the distobuccal root were evaluated at different time points using micro-CT system. Moreover, distance for mesial movement of the molar were measured. Microstructural parameters for trabecular bone of two groups showed no significant changes from day 0 to day 3 (P>0.05); from day 3 to day 7, bone mineral density (BMD), bone volume/total volume (BV/TV) and trabecular thickness (Tb.Th) decreased significantly (P<0.05), whereas trabecular separation (Tb.Sp) and structure model index (SMI) increased significantly (P<0.05); from day 7 to day 14, in 25-g group, BMD, BV/TV and Tb.Th increased significantly (P<0.05), while Tb.Sp and SMI decreased significantly (P<0.05). Correspondingly, in 75-g group, changes of parameters did not carry any statistical significance (P>0.05). Furthermore, the 75-g group showed larger distance than 25-g group only at day 14 (P<0.05). In conclusion, in order to maintain the health of periodontal tissues, adequate time for repair and recovery is needed to ensure reasonable remolding of alveolar bone and healthy movement of the orthodontic tooth.
RESUMEN
A simple and reliable ultra performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry method (UPLC-TOF-MS) was developed and validated for the simultaneous determination of the major bioactive constituents in Acanthopanax senticosus and its extract. The separation of five compounds was performed on a UPLC™ HSS T3 column (100 mm × 2.1 mm, 1.7 µm) with gradient elution using a mobile phase consisting of 0.1% aqueous formic acid and acetonitrile containing 0.1% formic acid. All targeted compounds (syringin, chlorogenid acid, caffeic acid, eleutheroside E and isofraxidin) were baseline separated within 5.3 min in samples, which represented an approximate six-fold reduction in the analysis time in comparison to published HPLC method. Quantitation was carried out working in the V mode using the narrow widow extracted ion chromatograms (nwXICs) of each compound (extracted using a 20 mDa window). Furthermore, all calibration curves showed good linearity (r > 0.999) within the test ranges. The precision was evaluated by intra- and inter-day tests, which revealed relative standard deviation (RSD) values of less than 3.88%. The recoveries for the quantified compounds were between 96.3% and 103.7%, with RSD values below 2.89%. According to the literature, this study represents the first investigation of the simultaneous analysis of multiple components and the method can be applied to determine the amounts of the major compounds in Acanthopanax senticosus and its extract by UPLC-TOF-MS.
