Detection of 14 sulfonate esters impurities of active pharmaceutical ingredients based on GC-MS/MS and LC-MS/MS / 药学学报

Two methods including gas chromatography tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) were established to detect common alkyl sulfonates and aryl sulfonates genotoxic impurities. Four alkyl sulfonates and methyl benzenesulfonate were determined by GC-MS/MS using butyl methanesulfonate as the internal standard, the chromatographic column was HP-5MS UI (30 mm × 0.25 mm, 0.25 µm), the carrier gas was helium, the flow rate was 1.0 mL·min-1 in a constant flow mode, the sample inlet temperature was set to 250 ℃, the split ratio was 10∶1, and the initial temperature of the heating program was 80 ℃, maintained for 1 minute, and then increased to 240 ℃ at a heating rate of 30 ℃·min-1 for 2 minutes. The mass spectrometry detector was an electron bombardment ion source (EI source), the data collection condition was multi reaction monitoring mode (MRM), and method validation using the raw material of clinical drug citalopram hydrobromide as a sample. The results showed that the linear range of four alkyl sulfonates and methyl benzenesulfonate were good at 3-50 ng·mL-1 and 9-150 ng·mL-1, with a correlation coefficient of r > 0.999, The spiked recovery was 80%-120%. The detection limits were 1 and 3 ng·mL-1; Ten aryl sulfonates determined by LC-MS/MS, the chromatographic column was CSH Fluoro phenyl (100 mm × 2.1 mm, 1.7 µm), the mobile phase was methanol (B)-5 mmol·L-1 ammonium formate (D), with a flow rate of 0.2 mL·min-1, and gradient elution was performed. The gradient program (T/% B) was set as 0/20, 25/90, 35/90, 42/20. The mass spectrometer detector was electro spray ionization with positive ionization mode (ESI+), the data collection was in dynamic multi reaction monitoring mode (dMRM), and the method was validated using the raw material of the clinical drug citalopram hydrobromide as a sample. The results showed that the linear range of aryl sulfonates were good at 9-2 000 ng·mL-1, 3-100 ng·mL-1 and 0.9-30 ng·mL-1, respectively. The correlation coefficient r > 0.999, the spiked recovery was 80%-120%. The detection limits were 30, 1 and 0.3 ng·mL-1. Two detection methods did not detect potential sulfonate genotoxicity impurities in the above APIs. The established analytical methods are reliable and effective, which can provide reference for drug quality control and detection.

Preliminary study on the clinical application of temporary treatment denture in difficult edentulous cases before complete denture restoration / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the clinical effects of treatment denture on difficult edentulous cases before complete denture restoration.</p><p><b>METHODS</b>Thirty-six patients who experienced unsuccessful restoration of conventional complete dentures were included in this study. Treatment dentures were fabricated to solve issues such as abnormal occlusion, tissue surface problems, and neuromuscular dysfunction of the stomatognathic system caused by systemic diseases. The final complete dentures were fabricated by duplicating the treatment dentures. Jaw relation index, stability, and retention were evaluated at different stages. Oral health-related quality of life was measured using the Chinese version of Oral Health Impact Profile for edentulous subjects (OHIP-EDENT).</p><p><b>RESULTS</b>Among the 36 patients, 33 successfully completed the final restoration with positive effects.</p><p><b>CONCLUSIONS</b>Treatment denture is an effective pre-restorative option that can be used to correct abnormal occlusion, improve tissue surface problems, and aid in neuromuscular rehabilitation training. Treatment dentures contribute to the successful restoration of the final complete dentures and is worthy of clinical applications.</p>

Study on the effects of zoledronic-acid-loaded collagen membrane on bone metabolism cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To develop zoledronic acid (ZA)-loaded collagen membranes, and to study its effect on osteoclast and osteoblast so as to investigate whether ZA-loaded membranes can inhibit local bone resorption and promote bone formation.</p><p><b>METHODS</b>ZA-loaded double-layer (Bio-Gide(®)) and single-layer (BME-10X(®)) collagen membranes were prepared and divided into eight groups according to the concentrations of ZA in the membrane, namely Group BG0, BG1, BG2, BG3 and BM0, BM1, BM2, BM3 (BG refers to Bio-Gide(®), BM refers to BME-10X(®), 0, 1, 2, 3 refer to the concentrations of ZA, 0, 1 × 10(-4), 1 × 10(-3), 1 × 10(-2) mol/L respectively). Blank control group was set without using collagen membrane. The effects of ZA-loaded membranes on osteoclast and osteoblast were assessed using in vitro cell culture models.</p><p><b>RESULTS</b>In vitro coculture of ZA-loaded membrane with osteoclast for seven days showed that the percentage of bone resorption area in BG1, BG2, BG3, BM1, BM2, BM3 were 18.80%, 14.75%, 14.28%, 20.51%, 15.77%, 15.12% respectively, which were lower than that in BG0 (31.53%) and BM0 (32.22%, P < 0.05), and the higher ZA loading was, the stronger its inhibition to osteoclast was. In vitro coculture of ZA-loaded membrane with osteoblast for four days indicated that alkaline phosphatase (ALP) activities in BG2 (154.67 U/g), BM2 (154.33 U/g), BG3 (155.33 U/g), BM3 (152.00 U/g) were higher than that in BG0 (129.33 U/g) and BM0 (127.67 U/g, P < 0.05). What's more, results from seven-day coculture showed that proliferation index in BG2 (7.00) was higher than that in BG0 (6.90).</p><p><b>CONCLUSIONS</b>ZA-loaded collagen membrane can not only inhibit osteoclastic bone resorption but also improve proliferation of osteoblast.</p>

Hydrogen sulfide induces apoptosis of pulmonary artery smooth muscle cell in rats with pulmonary hypertension induced by high pulmonary blood flow / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Abnormal apoptosis of pulmonary artery smooth muscle cells (PASMCs) is an important pathophysiological process in the pulmonary artery structural remodeling and pulmonary hypertension. We investigated possible effect of endogenous hydrogen sulfide (H2S) on apoptosis of PASMCs during the development of pulmonary hypertension induced by high pulmonary blood flow.</p><p><b>METHODS</b>Thirty-nine male Sprague-Dawley rats were randomly assigned to 4-week control, 4-week shunt, 4-week shunt + propargylglycine (PPG), 11-week control, 11-week shunt and 11-week shunt + sodium hydrosulfide (NaHS) groups. Rats in 4-week shunt, 4-week shunt + PPG, 11-week shunt and 11-week shunt + NaHS groups underwent an abdominal aorta-inferior vena cava shunt. Rats in 4-week shunt + PPG group were intraperitoneally injected with PPG, an inhibitor of endogenous H2S production, for 4 weeks. Rats in 11-week shunt + NaHS group were intraperitoneally injected with NaHS, a H2S donor, for 11 weeks. Lung tissue H2S was evaluated by sulfide-sensitive electrode. Apoptosis of PASMCs were detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling (TUNEL). Expressions of Fas, bcl-2 and caspase-3 in the PASMCs were analyzed with immunochemical staining.</p><p><b>RESULTS</b>Four weeks after the shunting operation, the apoptosis of PASMCs and expression of Fas and caspase-3 were significantly decreased (P < 0.01), but expression of bcl-2 increased significantly (P < 0.01). PPG administration further inhibited the apoptosis of PASMCs, downregulated the expression of Fas and caspase-3 (P < 0.01), but increased the expression of bcl-2 (P < 0.01). After 11 weeks of shunting operation, the apoptosis of PASMCs and expression of Fas and caspase-3 were significantly decreased (P < 0.01), but expression of bcl-2 increased obviously (P < 0.01). NaHS administration significantly increased the apoptosis of PASMCs, upregulated the expression of Fas and caspase-3, but inhibited the expression of bcl-2.</p><p><b>CONCLUSIONS</b>H2S induces the apoptosis of PASMCs in the development of high pulmonary blood flow-induced pulmonary hypertension by activating the Fas pathway and inhibiting the bcl-2 pathway.</p>

A clinical observation of therapeutic alliance of orthodontics and implant prosthodontics for dentition defect with malocclusion / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the clinical effect of the multidisciplinary treatment combined orthodontics with implant prosthodontics for cases of dentition defect with malocclusion.</p><p><b>METHODS</b>Seventeen cases of dentition defect with malocclusion were observed. All the cases accepted the orthodontic treatment in order to establish normal occlusion and achieve adequate space for implants. After that, the missing teeth were replaced by implant-supported denture. The clinical effect was evaluated by clinical examination and radiographic examination.</p><p><b>RESULTS</b>Satisfactory esthetic and functional results were achieved for all the cases. The follow-up time ranged from 12 months to 48 months. 76 implants were inserted totally. Two of them were extracted due to peri-implantitis. However, the other 74 implants were stable with an average loading time of 32 months. The cumulative survival rate was 97.4%.</p><p><b>CONCLUSION</b>The multidisciplinary approach combined orthodontics with implant prosthodontics was an effective treatment option for cases of dentiton defect with malocclusion.</p>

The prosthodontic three-dimensional multimedia system developed for dental education and chairside communication / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To develop a three-dimensional multimedia system for enhancing the efficiency of dental education and chairside communication.</p><p><b>METHODS</b>A set of three-dimensional digital models of normal teeth and jaws related to dental education in prosthodontics were acquired or established under Microsoft Windows. The three-dimensional models were re-edited and rendered with texture attached, producing a large number of three-dimensional pictures and short animated pictures. A software platform was established for displaying all sorts of media, including the three-dimensional models. Finally, all media files produced or gathered before were integrated into the platform, similar to the textbook in chapter adopted in dental education at university.</p><p><b>RESULTS</b>The prosthodontic three-dimensional multimedia system was successfully developed. The system covered basic information within the current textbook of prosthodontics, three-dimensional pictures, animated pictures, and virtual three-dimensional scenes. The system might serve as an assistant tool in dental education and chairside communication.</p><p><b>CONCLUSIONS</b>It is technically feasible to establish the prosthodontic three-dimensional multimedia system, according to experiences in this study. The success also anticipates the possibility and feasibility of developing similar systems in other disciplines of dentistry.</p>