Survival analysis of crown margin repair: A retrospective study in a dental school setting

BackgroundRepairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors’ objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival.MethodsRecords of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event.ResultsDuring the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam.ConclusionsMedian survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively.Practical ImplicationsWhen considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.     

Accounting for Unobservable Preference Heterogeneity and Evaluating Alternative Anchoring Approaches to Estimate Country-Specific EQ-5D-Y Value Sets: A Case Study Using Spanish Preference Data

ObjectivesThe EuroQol Group published the EQ-5D-Y valuation protocol that recommends 2 valuation techniques to elicit preferences: composite time trade-off (C-TTO) and discrete choice experiments (DCEs). The protocol left the decision of what modeling approach to use open for researchers. Our aims were to explore modeling strategies allowing generation of EQ-5D-Y value sets and to produce an EQ-5D-Y Spanish value set.MethodsWe used EQ-5D-Y DCE and C-TTO data collected in Spain following the protocol and adopted a staged approach for our modeling exercise. First, we selected the best performing DCE latent class model and evaluated models from 2 to 10 classes. We selected the preferred model based on best goodness of fit in terms of the Bayesian information criterion. We considered 2 anchoring approaches to estimate utility values: (1) pits state anchoring and (2) hybrid models (using all available C-TTO responses). All analysis were weighted to be representative of the Spanish population.ResultsWe collected 1005 DCE and 200 C-TTO interviews. We selected a DCE model including 4 classes. Hybrid models using all available C-TTO observations produced a narrower range of values than the pits state anchoring approach.ConclusionsIn this article, we have presented an EQ-5D-Y value set that can be used for cost-utility analysis in Spain. The international EQ-5D-Y valuation protocol should be updated to include a different set of health states for the C-TTO experiment if researchers wish to use alternative anchoring approaches to the “pits state.”     

中药调节黏膜免疫系统用于防治COVID-19的思路探索

机体免疫功能低下患者,极易出现新型冠状病毒感染,与中医所说正气不足、邪毒侵扰一致。目前集中在抗病毒药物研发是必须的,但对于调节机体免疫系统制剂的研究也较为迫切。黏膜组织是人体免疫系统的一道重要屏障,具有独特功能和结构的独立免疫体系,是机体抵抗感染的第一道防线,与外界抗原(比如食物、共生菌、病毒等)直接接触。其在抵抗病毒、抗感染方面,黏膜免疫(如呼吸道黏膜、肠道黏膜等)起着极其重要的作用,可以消灭外来病原微生物或其他外来抗原,不至于病毒侵入机体组织而对机体造成损伤。中药通过黏膜免疫系统发挥治疗作用的研究报道日益增多,该文拟针对黏膜免疫系统与新型冠状病毒肺炎(COVID-19)的关系以及中药的干预机制展开探讨,以期为COVID-19的防治提供可借鉴的研究方法与治疗思路。     

1,8-桉叶油素自微乳给药系统的制备及质量评价和细胞摄取研究

目的优化1,8-桉叶油素(1,8-cineole,1,8-Cin)自微乳给药系统(1,8-cineole self-microemulsion drug delivery system,1,8-Cin-SMEDDS)处方,对其进行表征并进行细胞摄取考察。方法通过绘制伪三元相图,确定1,8-Cin-SMEDDS有效自乳化区域,进行初步处方筛选。以粒径和载药量为指标,采用星点设计-效应面法对1,8-Cin-SMEDDS处方进行优化并验证。荧光显微镜观察高糖损伤的人脐静脉内皮细胞(HUVEC)对1,8-Cin-SMEDDS的摄取情况。结果 1,8-Cin-SMEDDS的最佳处方是大豆油(7.5%)与1,8-Cin(22.5%)为混合油相,HS15(56%)为乳化剂,乙醇(14%)为助乳化剂,滴加纯水至8m L得半透明略带蓝色乳光液体。透射电镜观察其外观呈球形液滴,激光粒度Zeta电位测定仪测得平均粒径为(131.68±1.44)nm,Zeta电位为(-10.03±1.63)m V;HPLC法测得包封率为(99.890±0.012)%,载药量为(224.750±0.028)mg/g。HUVEC细胞摄取实验结果表明,细胞对1,8-Cin-SMEDDS的摄取高于游离1,8-Cin。结论 1,8-Cin-SMEDDS制备方法简便,重复性好,所得1,8-Cin-SMEDDS外观良好,包封率高,理化性质稳定,且能促进细胞摄取。     

乙肝肝硬化肝胆湿热及肝肾阴虚证物质基础研究＊

目的 运用代谢组学技术分析乙肝肝硬化患者肝肾阴虚及肝胆湿热两种典型证候（同病异证）的血清差异代谢产物及其代谢通路，探寻虚、实两种典型证候的内在物质基础，以期从代谢水平上为中医证候分类提供客观依据。方法 对符合纳入标准的111例不同证候的乙肝肝硬化患者（肝胆湿热证40例，肝肾阴虚证41例，隐证(无证可辨）者30例）中医症状及体征进行描述性分析，发现两种不同证型的临床信息分布规律及证候特征；采用气相色谱-飞行时间质谱联用（GC-TOF/MS）技术对乙肝肝硬化患者，以及与之相匹配的60例健康人的血清样本进行检测，经非监督的主成分分析（Principal Components Analysis，PCA）、有监督的偏最小二乘判别分析（Partial Least Square Discriminant Analysis，PLS-DA）及监督的正交偏最小二乘法（Orthogonal Partial Least SquareDiscriminant Analysis，OPLS-DA）分析，找出与乙肝肝硬化疾病本身及其两种典型证候相关的差异性物质；运用MetaboAnalyst 3.0数据库，寻找并解析肝胆湿热及肝肾阴虚虚实两种证候间差异性物质的相关代谢通路。结果 （1）肝胆湿热证中出现频率较高（50%以上）的症状为小便色黄，口干，口苦，口臭或有异味等。肝肾阴虚证中出现频率较高的症状为口干、腰酸、乏力、腿软等。两证共见症/征为口干、尿黄、易怒、舌红。（2）各组间丙氨酸氨基转移酶（Alanine Aminotransferase,ALT）数值无统计学差异（P > 0.05）；与健康组比较，隐证组中白蛋白（Albumin，ALB），肝胆湿热证中总胆红素（Total Bilirubin，TBil）、直接胆红素（Direct Bilirubin，DBil）、谷草转氨酶（Aspartate Transaminase，AST）、碱性磷酸酶（Alkaline Phosphatase，ALP）、谷氨酰转肽酶（Gamma-Glutamyl Transpeptidase，GGT）、总胆汁酸（Total Biliary Acid，TBA）及ALB，肝肾阴虚证TBil、ALP、GGT、TBA、ALB值差异均有统计学意义（P < 0.05）；与隐证比较，肝胆湿热证TBil、DBil、AST、ALP、TBA、ALB，肝肾阴虚证TBA、ALB差异有统计学意义（P < 0.05）；肝胆湿热证与肝肾阴虚证相比，TBil、DBil差异有统计学意义（P < 0.05）。（3）代谢组学检测及代谢通路分析，发现各组之间代谢谱均有良好的区分，并获得各组间的差异性物质。发现肝胆湿热及肝肾阴虚两典型证的共同物质10个，去除疾病（隐证）的信息，则得到两证共同物质6个，涉及的代谢通路为甘氨酸、丝氨酸及苏氨酸代谢和苯丙氨酸代谢；同时，分别获得两证各自特异性的代谢物质各8个，分别涉及亚油酸代谢和甘氨酸、苏氨酸及丝氨酸代谢。结论 运用代谢组学技术，发现肝胆湿热及肝肾阴虚不同证之间既存在病的共同物质（同病），也存在证的差异物质（异证），从而在代谢层面上为中医证候分类的科学性提供科学依据。     

星点设计-效应面法优化丁香苦苷聚乳酸-羟基乙酸纳米粒的制备工艺

目的优化丁香苦苷聚乳酸(Syr)-羟基乙酸共聚物[poly(lactic-co-glycolic acid),PLGA]纳米粒(Syr-NPs)的处方。方法采用纳米沉淀法制备Syr-NPs,以包封率、载药量、平均粒径以及总评"归一值"为评价指标,采用星点设计-效应面法考察PLGA质量浓度(A)、丁香苦苷质量浓度(B)、水相与有机相比例(C)3因素考察对包封率、载药量、平均粒径以及总评归一值的影响,以星点设计-效应面法选取最佳处方条件进行预测分析。结果最优处方工艺为PLGA质量浓度为9.63 mg/mL,Syr质量浓度为12.88 mg/mL,有机相与水相的比例为1∶9.46,制得的Syr-NPs的包封率、载药量、平均粒径分别为(27.86±0.87)%、(7.02±0.15)%、(110.0±1.20)nm。结论该方法稳定可行,可用于优化包载Syr的PLGA纳米粒处方与制备工艺。     

Is There Material Loss at the Conical Junctions of Modular Components for Total Knee Arthroplasty?

BackgroundClinical concern exists regarding fretting corrosion and material loss from taper junctions in orthopedic devices, with previous research focusing on the modular components from total hip arthroplasty. Comparatively little has been published regarding the fretting corrosion and material loss in modular knee devices. The purpose of this study is to evaluate fretting corrosion damage and quantify material loss for conical total knee arthroplasty taper interfaces.MethodsStem tapers of 166 retrieved modular knee devices were evaluated for fretting corrosion using a semiquantitative scoring method. High precision profilometry was then used to determine volumetric material loss and maximum wear depth for a subset of 37 components (implanted for 0.25-18.76 years). Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to characterize the observed damage.ResultsMild to severe fretting corrosion was observed on the majority of tapers, with 23% receiving a maximum visually determined damage score of 4. The median rate of volumetric material loss was 0.11 mm³/y (range 0.00-0.76) for femoral components (both cone and bore taper surfaces combined) and 0.01 mm³ (range 0.00-8.10) for tibial components. Greater rates of material loss were associated with mixed metal pairings. There was a strong correlation between visual fretting corrosion score and calculated material loss (ρ = 0.68, P < .001). Scanning electron microscopy revealed varying degrees of scratching, wear, fretting corrosion, and instances of cracking with morphology not consistent with fretting corrosion, wear, or fatigue.ConclusionAlthough visual evidence of fretting corrosion damage was prevalent and correlated with taper material loss, the measured volumetric material loss was low compared with prior reports from total hip arthroplasty.     

甲状腺手术切口入路、缝合技术与缝合材料选择中国专家共识（2018版）

正随着外科手术技术的发展和人们对美学追求的不断提高,病人对甲状腺术后切口外观的重视程度也越来越高。如何在保证甲状腺手术质量的前提下,最大限度地降低手术对各解剖层次的损伤,减轻切口瘢痕,满足病人的美容要求,一直是外科医生追求的目标。目前,关于甲状腺手术切口入路、缝合技术及缝合材料选择方面的报道并不多,术者多以临床经验和个人习惯进行操作,存在的差异也较大。中华医学会外科学分会组织国内部分专家参考