A quantitative assessment of cross-sectional cortical bone remodeling in the femoral diaphysis following hip arthroplasty in elderly females

A quantitative assessment of cross-sectional cortical bone remodeling in the femoral diaphysis following hip arthroplasty was made by direct in vitro measurements of cross-sectional geometric properties. We obtained eight femora from four female cadavers ranging in age from 77 to 96 years. In three cases unilateral uncemented Austin Moore implants were used, and in one case a unilateral cemented Thompson prosthesis had been implanted. The time of implantation in the two specimens where this information could be obtained was greater than 40 months. Sections were made at 12 diaphyseal locations from the superior aspect of the lesser trochanter through the distal diaphysis. Section properties (areas and second moments of area, or area moments of inertia) were determined by tracing photographs of the cross-sections with a digitizer. In this sample of prosthetic femora, we found reductions in both total subperiosteal area (TA) and endosteal area (ENDA) relative to the contralateral unoperated side in most sections distal to the lesser trochanter. The average pairwise reduction in ENDA for this region was 21.1 mm2, reaching statistical significance in one distal diaphyseal section. The average decline in TA in this region was 10.2 mm2. Because the reduction in endosteal dimensions was generally greater than the reduction in subperiosteal dimensions, cortical area (CA) was maintained or increased throughout the distal 80% of this region in prosthetic femora with an average increase in CA of 9.3 mm2, reaching statistical significance in one mid-diaphyseal section. A completely different pattern of remodeling occurred in the two most proximal sections through the lesser trochanter and base of the femoral neck.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age changes in geometry and mineral content of the lower limb bones

Subperiosteal expansion and increase in second moments of area with aging of eleven femoral and tibial cross-sections are documented in a large archaeological sample from the American Southwest. In contrast to these geometric changes, we found little change with age in bone mineral density measured using photon absorptiometry. Thus, the most significant structural changes with age in bone appear to involve its geometry and material characteristics other than its density. Variation in age-related geometric remodeling between cross-section locations and populations may be caused by differences in mechanical stress and strain levels in vivo in the lower limb.     

Association of antiviral prophylaxis and rituximab use with posttransplant lymphoproliferative disorders (PTLDs): A nationwide cohort study

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of solid organ transplantation (SOT). Most PTLD cases are associated with Epstein–Barr virus (EBV) infection. The role of antiviral prophylaxis or rituximab therapy for prevention of PTLD in SOT recipients is controversial. In a nationwide cohort, we assessed the incidence, presentation, and outcome of histologically proven PTLD. We included 4765 patients with a follow-up duration of 23 807 person-years (py). Fifty-seven PTLD cases were identified; 39 (68%) were EBV positive (EBV+ PTLD). Incidence rates for EBV+ PTLD at 1, 2, and 3 years posttransplant were 3.51, 2.24, and 1.75/1000 py and 0.44, 0.25, and 0.29/1000 py for EBV− PTLD. We did not find an effect of antiviral prophylaxis on early and late EBV+ PTLD occurrence (early EBV+ PTLD: SHR 0.535 [95% CI 0.199–1.436], p = .264; late EBV+ PTLD: SHR 2.213, [95% CI 0.751–6.521], p = .150). However, none of the patients (0/191) who received a rituximab-containing induction treatment experienced PTLD, but 57 of 4574 patients without rituximab induction developed PTLD. In an adjusted restricted mean survival time model, PTLD-free survival was significantly longer (0.104 years [95% CI 0.077–0.131]) in patients receiving rituximab as induction treatment. This study provides novel data on the association of rituximab induction and reduced risk for PTLD.     

近10年国内针灸临床试验研究病种计量分析

为了解近年来国内针灸临床试验研究中涉及的病种情况,并且与之前国外针灸临床试验研究的结果进行对比,本研究采用文献计量的方法,通过对中国中医药期刊文献数据库收录的近10年(2003年至2012年)的针灸临床试验研究的文献进行调研,得出有关中西医疾病病名的主题词1187个,并列举其中排名前100位的高频词。与国内外前期的研究报道进行比较,认为国内针灸临床研究涉及的疾病种类远远超过国外,并且在不断扩充。     

缺血性心肌病的左心室几何变化与心功能关系

目的 探讨缺血性心肌病(ischemic cardiomyopathy,ICM)病人左心室几何形态学变化与其心功能的关系.方法 应用彩色多普勒超声测量ICM 65例及正常人30名左心室几何形态学及其有关左心室收缩功能和舒张功能指标;以左心室球形指数(sphericity index,SI)即左心室长径/短径比值(L/D)作为反映左心室几何构型的变化,比较ICM病人及正常人左心室射血分数(left ventricular ejection fraction,LVEF)、短轴缩短率(shortening fraction,FS)、心脏指数(cardiac index,CI)、收缩期左心室球形指数(left ventricular geometry sphericity index at the end of systole,SIs)、舒张期左心室球形指数(left ventricular geometry sphericity index at the end of diastole,SId)差异,并对各参数行相关分析.结果 ICM病人SI明显降低,SIs与LVEF呈正相关(r=0.7452),SId与EVI/AVI呈正相关(r=0.6597).结论 ICM左心室几何形态变化与其心功能密切相关,心功能愈差,左心室愈趋球形,心室球形化的程度可能预示心功能的减退程度.     

Fusion of white and gray matter geometry: A framework for investigating brain development

Current neuroimaging investigation of the white matter typically focuses on measurements derived from diffusion tensor imaging, such as fractional anisotropy (FA). In contrast, imaging studies of the gray matter oftentimes focus on morphological features such as cortical thickness, folding and surface curvature. As a result, it is not clear how to combine findings from these two types of approaches in order to obtain a consistent picture of morphological changes in both gray and white matter.In this paper, we propose a joint investigation of gray and white matter morphology by combining geometrical information from white and the gray matter. To achieve this, we first introduce a novel method for computing multi-scale white matter tract geometry. Its formulation is based on the differential geometry of curve sets and is easily incorporated into a continuous scale-space framework.We then incorporate this method into a novel framework for “fusing” white and gray matter geometrical information. Given a set of fiber tracts originating in a particular cortical region, the key idea is to compute two scalar fields that represent geometrical characteristics of the white matter and of the surface of the cortical region. A quantitative marker is created by combining the distributions of these scalar values using Mutual Information. This marker can be then used in the study of normal and pathological brain structure and development. We apply this framework to a study on autism spectrum disorder in children. Our preliminary results support the view that autism may be characterized by early brain overgrowth, followed by reduced or arrested growth (Courchesne, 2004).     

吲哚胺2,3-双加氧酶在肿瘤及肿瘤耐药中的研究现状

吲哚胺2,3-双加氧酶(IDO)是一种肝外催化色氨酸沿犬尿氨酸途径降解的限速酶。IDO抑制药被用在不同恶性肿瘤及耐药肿瘤治疗的相关实验中,特别是与放疗和化疗相结合时取得了良好的效果。本文将对IDO及其抑制药对肿瘤及肿瘤耐药的影响进行综述。     

Peptide encapsulation regulated by the geometry of carbon nanotubes

In this work the encapsulation of an α-helical peptide in single carbon nanotubes (CNTs) with similar diameter and length but different geometry (armchair and zigzag) was investigated through molecular dynamics simulations and free energy calculations. Our simulation results showed that in vacuo it makes no evident difference whether the investigated peptide is encapsulated in armchair or zigzag CNTs; however, in aqueous solution the armchair CNT encapsulates the peptide remarkably easier than the zigzag CNT does. A detailed analysis revealed that the equilibrium conformation of the water molecules inside the CNTs with varying geometry mediates the peptide encapsulation. It suggests that the water molecules play an important role in regulating behaviors of biomolecules in bio-systems. Then the impact of the CNT geometry on the conformational changes of the confined peptide was studied. Analyses of secondary structures showed the α-helix of the peptide could be better maintained in the zigzag CNT.     

UPLC–MS/MS同时测定大鼠血、脑脊液中奎硫平及其活性代谢物

 目的建立同时测定大鼠血、脑脊液中奎硫平及其活性代谢物7-羟基奎硫平羟7-羟基-N-去烷基奎硫平浓度的UPLC-MS/MS法。方法样品经碱化后用叔丁基甲醚提取,采用Acquity UPLC^TM BEH C₁₈柱(2.1mm×50mm,1.7μm),柱温40℃,以水(含50mmol·L^-1醋酸铵,3‰甲酸)-乙腈(73∶27)为流动相,流速0.25mL·min^-1,进样量5μL。采用电喷雾离子化四极杆串联质谱,选择离子监测方式进行扫描,测定样品浓度,卡马西平作为内标。结果血浆中:奎硫平在0.0775～155μg·L^-1,7-羟基奎硫平在0.049～98μg·L^-1,7-羟基-N-去烷基奎硫平在0.067～670μg·L^-1内线性关系良好,萃取回收率均>89%,方法回收率均>87%,,内羟,间,密度RSD均<9%。脑脊液中:奎硫平在0.02～38.75μg·L^-1,7-羟基奎硫平在0.0098～29.5μg·L^-1,7-羟基-N-去烷基奎硫平在0.067～670μg·L^-1内线性关系良好,萃取回收率均>87%,方法回收率均>85%,,内羟,间,密度RSD均<16%。结论该方法该该度高、快速羟该确羟有效,且血、脑中浓度均可测定,为研究转运蛋白对抗,神分裂药物进入血脑屏障的影响提供了依据。