Assessment of dental implant surface stability at the nanoscale level

ObjectivesTo study the oxide layer stability of certified dental implants of system "P", made based on TiO₂ alloy with carbon coating. To perform a comparative statistical analysis of the obtained data with the available data for the dental implants of systems "A" and "B".MethodsX-ray microtomography and X-ray fluorescence analysis were used to study soft tissue biopsy specimens. Supernatants were studied by dynamic light scattering and transmission electron microscopy when simulating free emission of nanoscale metal oxide particles from the surface of dental implants as well as when simulating physical loading. A comparative analysis of three parameters of nanoscale particles was performed by statistical data analysis. The surface of the "P" system dental implant with surface treatment was analyzed by scanning electron microscopy.ResultsBoth free emission of nanoscale oxide layer particles and yield of nano- and microscale particles during simulation of physical load were confirmed. Statistically significant differences were noted in a comparative analysis of the size and frequency of occurrence of these particles in the supernatants obtained from the surfaces of three dental implant systems. The elemental composition of the particles and the composition and structure of the "P" system dental implants themselves were analyzed.SignificanceThe developed method of dynamic light scattering can be used to compare the stability of the oxide layer of standardized medical products manufactured on the basis of the TiO₂ alloy.     

利用电子顺磁波谱技术研究红参对羟自由基的清除作用

目的 探索电子顺磁波谱（electron paramagnetic resonance，EPR）技术检测红参清除自由基活性的适合产生体系，并研究红参对羟自由基（?OH）的清除作用及其物质基础。方法 采用电子顺磁共振波谱仪检测不同浓度的红参提取液对?OH的体外清除作用，并用液质联用技术（LC-MS）分析红参中的主要皂苷成分，然后研究这些人参皂苷成分对?OH的清除作用。结果 确定了羟自由基的生成体系为：Fe²⁺ 0.1 mmol?L^-1、H₂O₂ 500 mmol?L^-1、DMPO 225 mmol?L^-1；不同浓度的红参提取液对?OH具有明显的清除作用，且其清除?OH的效力与浓度成正相关；LC-MS分析显示该红参提取液中主要含有Rh1、Rf、Rb3、F1、F2、Rg3、Rg5等成分，其中人参皂苷Rg5的清除自由基活性最强。结论 本研究建立了用EPR技术研究红参清除自由基活性的适合产生体系，红参具有明显的清除?OH的能力，且人参皂苷Rg5是其清除自由基的活性成分之一，确定了红参抗自由基的主要物质基础，为红参及人参皂苷Rg5的开发、应用提供了科学依据和理论基础。     

Preparation,characterization, and antibacterial activity of plaunotol and plaunoi extracts complexed with hydroxypropyl-β-cyclodextrin

Croton stellatopilosus (Plaunoi) leaves accumulate several diterpenes and possess various pharmacological activities. The present study aimed to prepare, characterize and assess the antibacterial activity of inclusion complexes prepared by mixing plaunotol (PL) or plaunoi extract (PE) with cyclodextrins (CD), including α-CD, β-CD, γ-CD, and hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexes were characterized using SEM, XRD, DSC, and FT-IR and evaluated for aqueous solubility and thermal stability. The PL and PE lyophilized complexes with HP-β-CD were further evaluated for their antibacterial activity against acne-causing bacteria. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of PL, PE, and the inclusion complexes evaluated using the agar dilution method revealed that the MIC and MBC values of the inclusion complexes were lower than those of PL or PE alone. Interestingly, the complexes had a synergistic activity with clindamycin after testing with checkerboard assay. The hydrogel containing the inclusion complex and clindamycin were assessed for antibacterial activity using the agar well diffusion method. The results indicated that the hydrogels showed significant inhibition of bacterial growth. In conclusion, the prepared solid dispersion of PL or PE with HP-β-CD could enhance antibacterial activity by increasing the drug solubility. The hydrogels containing PL or PE complex and clindamycin could be considered as a candidate for the treatment of acne vulgaris.     

口腔手术显微镜联合锥形束CT辅助治疗上颌第一前磨牙遗漏远颊根管1例报告

遗漏根管是根管治疗失败的常见原因,避免根管遗漏对提高根管治疗成功率至关重要。上颌第一前磨牙根管解剖形态变异较大,多为颊腭双根管或单根管,极少存在三根管[1]。研究表明,汉族人上颌第一前磨牙三根管的发生率为0.2%~1.8%[2-4]。如何识别可能存在的遗漏第三根管是上颌第一前磨牙根管治疗过程中的难点。本文报道了1例口腔手术显微镜联合锥形束CT(CBCT)辅助治疗上颌第一前磨牙根管治疗中远颊根管遗漏的病例,以期为临床治疗提供参考。     

酸枣仁汤对老年慢性快动眼睡眠剥夺模型大鼠肝脏线粒体能量代谢及其机制的影响

目的 研究酸枣仁汤对老年慢性睡眠剥夺模型大鼠肝脏线粒体能量代谢的影响及作用机制。方法 将50只雄性Wistar大鼠随机分为正常组，模型组、舒乐安定组（0.18 mg·kg^-1·d^-1），酸枣仁汤低、高剂量组（6.48，12.96 g·kg^-1·d^-1），除正常组外，其余各组均皮下注射D-半乳糖，于末次给药后进行多平台水环境睡眠剥夺，造模结束后各组开始灌胃给药，连续给药7 d。采用透射电镜观察肝脏线粒体形态，采用比色法检测大鼠肝脏三磷酸腺苷（ATP）含量的变化，采用比色法检测大鼠肝脏线粒体呼吸链还原型辅酶Ⅰ（复合物Ⅰ），琥珀酸氧化还原酶（复合物Ⅱ），细胞色素C氧化还原酶（复合物Ⅲ），细胞色素C氧化酶（复合物Ⅳ）活性，采用蛋白免疫印迹法（Western blot）检测大鼠肝脏柠檬酸合酶（CS），异柠檬酸脱氢酶（IDH），负责编码ATP合成酶F0亚基的一段核基因（ATP5F1）蛋白的表达水平。结果 与正常组比较，模型组大鼠肝脏内线粒体损伤较严重，线粒体发生肿胀、变形，嵴断裂并且数量有一定的减少，与模型组比较，舒乐安定组、酸枣仁汤高剂量组线粒体损伤减轻，肿胀、变形情况显著减少，嵴断裂减少，其中酸枣仁汤高剂量改善较为明显。与正常组比较，模型组大鼠肝脏ATP含量显著降低（P<0.01），线粒体呼吸链复合物Ⅰ，Ⅱ，Ⅲ，Ⅳ活性均显著降低（P<0.01），IDH，CS，ATP5F1蛋白表达均显著降低（P<0.01）；与模型组比较，酸枣仁汤高剂量组肝脏ATP含量显著升高（P<0.01），线粒体呼吸链复合物Ⅰ，Ⅱ，Ⅲ，Ⅳ活性均明显升高（P<0.05，P<0.01），IDH，CS，ATP5F1蛋白表达均显著升高（P<0.01），舒乐安定组肝脏ATP含量明显升高（P<0.05），线粒体呼吸链复合物Ⅰ，Ⅲ活性显著升高（P<0.01），CS，ATP5F1蛋白表达均显著升高（P<0.01），酸枣仁汤低剂量组肝脏线粒体呼吸链复合物Ⅰ，Ⅲ活性明显升高（P<0.05，P<0.01），ATP5F1蛋白表达明显升高（P<0.05）。结论 酸枣仁汤可以改善老年慢性睡眠剥夺引起的肝脏能量代谢异常，其机制可能与上调线粒体电子链酶活性，CS，IDH及ATP5F1蛋白表达有关。     

SMILE术中角膜帽下地塞米松平衡液冲洗与否的早期临床观察

目的观察飞秒激光小切口角膜基质透镜取出术(SMILE)中角膜帽下地塞米松平衡液冲洗与否对术后视觉质量及角膜组织结构形态的影响。方法选择拟进行双眼SMILE手术的24例(48眼)纳入研究,每例患者随机选取一眼透镜取出后,行地塞米松平衡液冲洗角膜帽下基质腔隙(实验组),对侧眼不冲洗(对照组)。分别于术后第1天、第7天及1个月对比观察两组的裸眼视力、屈光状态、角膜中央厚度(CCT)、眼压(NCT);同时利用共焦显微镜及前段光学相干断层扫描(OCT)检查对比观察两组角膜上皮细胞、神经纤维、基质细胞、内皮细胞形态结构。采用配对t检验比较两组的裸眼视力、屈光状态等各指标有无差异。结果术后第1天、第7天及1个月两组间裸眼视力比较:实验组为4.99±0.07、5.06±0.08、5.05±0.06;对照组为5.01±0.07、5.05±0.08、5.06±0.09;3个时间点两组间裸眼视力均无统计学差异(P均>0.05);术后第1天、第7天及1个月的屈光度(SE,D):实验组为0.03±0.49、0.1±0.37、0.02±0.4;对照组为0.09±0.54、0.19±0.48、0±0.52,3个时间点两组间SE比较均无统计学差异(P均>0.05)。共焦镜检查不同时间点比较:角膜上皮层细胞密度[术前(4578.73±268.40,4539.57±329.25)个/mm^2,术后第1天(4565.21±247.31,4627.23±271.03)个/mm^2,术后第7天(4640.01±246.79,4517.71±281.43)个/mm^2];角膜内皮细胞密度[术前(2541.50±259.59,2443.52±305.58)个/mm^2,术后第1天(2387.01±248.55,2495.27±238.52)个/mm^2,术后第7天(2484.49±223.71,2482.53±323.82)个/mm^2],术前术后两组间均无统计学差异(P>0.05);角膜上皮下神经纤维丛术前术后两组间比较无明显变化;切削界面高反光物两组间比较没有明显差异;角膜前基质细胞密度[术前(789.51±67.17,802.03±67.94)个/mm^2,术后第1天(889.37±60.62,912.27±95.87)个/mm^2,术后第7天(796.67±75.03,818.39±59.65)个/mm^2]在术后第1天、第7天较术前均有增加,但两组之间没有统计学差异(P>0.05),术后1 d两组前基质细胞较术前增加,有统计学差异(P<0.05);角膜后基质细胞术后各时间点两组间比较无统计学差异(P>0.05)。角膜OCT在术后1 d、7 d两组在角膜帽下均未出现明显层间间隙和积液,两组间角膜中央厚度无统计学差异(P>0.05)。结论SMILE术中地塞米松平衡液角膜帽下冲洗对术后裸眼视力、屈光度及角膜组织结构形态无明显影响。     

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??Obtaining quality photographs of the clinical cases are crucial for case record??communication with the patient or between dentists. Along with the rapid increase of the clinical application of dental microscope in the daily practice??it becomes a challenge of the practitioners to get qualified photographs through an operating microscope. In this paper??the dental microscope history??the differences between microscopic photography and traditional dental photography??microscope equipment and the skills in microscopic photography were discussed in detail??to provide the reference for clinical application of dental microscopic photography.     

Signet ring cell mesothelioma; A diagnostic challenge

Signet ring cell mesothelioma is a rare variant of epithelioid mesothelioma with limited cases published. It has a male predilection and most commonly occurs on pleura; it can also arise in the peritoneal cavity. The signet ring cell morphology can pose a challenge leading to a potential diagnostic error. A variety of benign and malignant diseases, including reactive histiocytic hyperplasia, adenocarcinoma, melanoma, and lymphoma with signet ring cell morphology should be considered in the differential diagnosis. In signet ring cell mesothelioma work up, mucin stains are of limited value. Even though immunohistochemistry is routinely used in mesothelioma diagnosis, there is no sole specific mesothelial marker. Hence, a panel of mesothelial and epithelial markers are used; these should be interpreted with caution especially in this variant. Electron microscopy and genetic testing can be very helpful in distinguishing signet ring cell mesothelioma from its mimickers.