Validation of micro-CT against the section method regarding the assessment of marginal leakage of sealants

Background: The aim of this study was to validate the micro‐CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant‐enamel interface. Methods: Pits and fissures of the occlusal surface of 10 teeth were sealed with a resin‐fissure sealant material without acid etching, thermocycled for 5000 cycles, immersed in 50% silver nitrate for three hours and scanned using micro‐CT. Teeth were embedded in epoxy resin and cut in three sections. The middle section was subjected to micro‐CT and stereomicroscopy. Images were taken from the left and right sides of the sealant‐enamel interface at both the left and the right site of the section. Two experienced evaluators assessed marginal leakage. Results: Both assessment instruments observed no leakage in 37 out of the 40 images evaluated. Leakage at the sealant‐enamel interface was observed in three stereomicroscopy images only. A fracture line in the sealant was seen on eight stereomicroscopy images and observed in only two micro‐CT images. Conclusions: The quality of the micro‐CT and related software used in the present study does not qualify it to replace the section method as the gold standard for marginal leakage assessment at the sealant‐enamel interface of permanent teeth.     

改善愈合微环境是中西医创面治疗的共同思路

中医和西医创面治疗的根本是有效去除影响创面愈合的障碍性因素,改善创面愈合的微环境,提高组织的再生修复能力,进而加速创面愈合,提高创面愈合质量。两者都是通过补充和调控外源/内源性生长因子的合成和分泌,促进细胞分裂增殖,刺激创面新生血管形成,改善创面的血液循环,调控胶原的合成及代谢,调节创面修复基质形成,营养创面等方式发挥作用。在改善创面微环境的核心理念基础上,将两类方法有机地加以组合,可以加速创面修复。     

Modern drug delivery strategies applied to natural active compounds

Introduction: Colloidal drug delivery systems (CDDSs) are innovative carriers that have been studied in pharmaceutical field from many years to overcome unfavorable physical and chemical features of synthetic drugs. Recently the use of CDDS as carriers for phytochemicals has seen an exponential increase which, in some cases, has led to the rediscovery of ancient and forgotten natural molecules.

Area covered: This article focuses on the main features of CDDS, particularly micro- and nanoemulsions, vesicular carriers and micro- and nanoparticles, loaded with natural active compounds. A detailed review of the literature is presented, introducing the importance of these systems in terms of their capability to optimize the stability of phytochemicals, their absorption through biological membranes and their bioavailability.

Expert opinion: The delivery of phytochemicals is problematic due to poor solubility, poor permeability, low bioavailability, instability in biological milieu and extensive first-pass metabolism. Global research efforts investigating nanotechnology have attempted to overcome these limitations rediscovering and, in some cases, ‘discovering ex novo’ unexpected virtues and benefits associated to these compounds. The ‘nanotechnological approach’ can definitely enhance the pharmacokinetics and therapeutic index of natural active compounds and improve their performance in therapy.     

Construct damage and loosening around glenoid implants: A longitudinal micro‐CT study of five cadaver specimens

The evolution of failure of bone and cement leading to loosening of glenoid components following shoulder arthroplasty is not well understood. The purpose of this study was to identify and visualize potential mechanisms of mechanical failure within cadavers, cemented with two types of components, and subject to cyclic loading. Five glenoid cadaver bones were implanted with either a three‐pegged polyethylene component, or prototype posteriorly augmented component which addresses posterior bone loss. Specimens were loaded by constant glenohumeral compression combined with cyclic anterior–posterior displacement of the humeral head relative to the glenoid. At six time points across 100,000 cycles, implant loosening micromotions were optically measured, and specimens were imaged by micro‐computed tomography. Scans were 3D registered and inspected for crack initiation and progression, and micro‐CT based time‐lapse movies were created. Cement cracking initiated at stress concentrations and progressed with additional cyclic loading. Failure planes within trabecular bone and the bone–cement interface were identified in four of the five specimens. Implant subsidence increased to greater than 1.0 mm in two specimens. Cemented glenoid structural failure can occur within the cement, along planes of trabecular bone, or at the bone cement interface. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1053–1060, 2016.     

Complexity of Host Micro‐RNA Response to Cytomegalovirus Reactivation After Organ Transplantation

Human (Homo sapiens) micro‐RNAs (hsa‐miRNAs) regulate virus and host‐gene translation, but the biological impact in patients with human cytomegalovirus (hCMV) infection is not well defined in a clinically relevant model. First, we compared hsa‐miRNA expression profiles in peripheral blood mononuclear cells from 35 transplant recipients with and without CMV viremia by using a microarray chip covering 847 hsa‐miRNAs. This approach demonstrated a set of 142 differentially expressed hsa‐miRNAs. Next, we examined the effect of each of these miRNAs on viral growth by using human fibroblasts (human foreskin fibroblast‐1) infected with the hCMV Towne strain, identifying a subset of proviral and antiviral hsa‐miRNAs. miRNA‐target prediction software indicated potential binding sites within the hCMV genome (e.g., hCMV‐UL52 and ‐UL100 [UL = unique long]) and host‐genes (e.g., interleukin‐1 receptor, IRF1). Luciferase‐expressing plasmid constructs and immunoblotting confirmed several predicted miRNA targets. Finally, we determined the expression of selected proviral and antiviral hsa‐miRNAs in 242 transplant recipients with hCMV‐viremia. We measured hsa‐miRNAs before and after antiviral therapy and correlated hsa‐miRNA expression levels to hCMV‐replication dynamics. One of six antiviral hsa‐miRNAs showed a significant increase during treatment, concurrent with viral decline. In contrast, six of eight proviral hsa‐miRNAs showed a decrease during viral decline. Our results indicate that a complex and multitargeted hsa‐miRNA response occurs during CMV replication in immunosuppressed patients. This study provides mechanistic insight and potential novel biomarkers for CMV replication.     

微课在中医诊断学教学中的运用和评价

中医学是源于我国的传统医学,中医诊断学是中医学专业课程体系中的主干课程,它不仅涵盖了中医诊断的基本理论和知识,而且还涉及到基本的临床操作技能。中医诊断学是我校的国家级精品课程,我校所有本科专业均开设了该课程。该课程知识点多、信息量大、内容零散、包含许多中医术语,传统灌输式授课法容易给学生带来枯燥乏味、抽象繁杂的感觉,从而降低学生的学习兴趣和效率,制约教学质量的提升。为增强学生的应用实践能力,提高学生的中医临床分析思维能力,本教研团队一直致力于改革和探索新型的中医诊断学教学方法,已经实践过的教学方法有PBL 教学法[1]、慕课、网络资源共享课[2-3]、数字化实验实训课程等[4]。     

Evaluation of the vascular architecture of hepatocellular carcinoma by micro flow imaging: pathologic correlation.

OBJECTIVE: The purpose of this study was to evaluate micro flow imaging (MFI) in depicting the vascular architecture of hepatocellular carcinoma (HCC) and the correlation between pathologic differentiation and the intratumoral vascular architecture pattern. METHODS: Micro flow imaging and contrast harmonic imaging (CHI) were performed in 37 patients with HCC. A sulfur hexafluoride-filled microbubble contrast agent was used. The enhancement level and intratumoral vessels were evaluated on CHI. The vascular architecture of each tumor was evaluated on MFI. Pathologic differentiation of the tumors was classified according to the Edmondson grading system. RESULTS: All 37 HCCs showed hyperenhancement in the arterial phase and hypoenhancement in the portal and late phases on CHI. Intratumoral vessels in the arterial phase were visualized in 20 (54.1%) HCCs. On MFI, the vascular architecture in all lesions was clearly delineated and categorized into 3 patterns: cotton, shrubbery, and deadwood, identified in 12 (32.4%), 22 (59.5%), and 3 (8.1%) of the tumors evaluated, respectively. A chi(2) test showed that pathologic differentiation significantly correlated to the vascular pattern (P = .006). Three (75%) of 4 Edmondson grade I HCCs showed the cotton pattern; 18 (75.0%) of 24 Edmondson grade II HCCs showed the shrubbery pattern; and the deadwood pattern was shown only in Edmondson grade III and IV HCCs. CONCLUSIONS: The MFI technique is more effective in depicting the intratumoral vascular architecture. The vascular architecture pattern correlates with pathologic differentiation of HCC.     

迷你腹腔镜甲状腺切除术

目的 探索迷你腹腔镜甲状腺切除术的可行性、微创性及临床应用价值.方法 对33例甲状腺肿瘤患者行迷你腹腔镜甲状腺肿瘤切除术.结果 手术成功32例,中转开放1例.手术时间28～180min,术中出血量2～120mL.无术后大出血、窒息、声音嘶哑、手足抽搐等严重并发症,术中、术后无死亡病例.结论 迷你腹腔镜甲状腺切除术是安全可行的.手术切口隐蔽,愈合后几乎不留疤痕,创伤小,美容效果好,有望成为腹腔镜甲状腺切除术的主流术式.