Predicting full thickness skin sensitization using a support vector machine

To assess the public’s propensity for allergic contact dermatitis (ACD), many alternatives to in vivo chemical screening have been developed which generally incorporate a small panel of cell surface and secreted dendritic cell biomarkers. However, given the underlying complexity of ACD, one cell type and limited cellular metrics may be insufficient to predict contact sensitizers accurately. To identify a molecular signature that can further characterize sensitization, we developed a novel system using RealSkin, a full thickness skin equivalent, in co-culture with MUTZ-3 derived Langerhan’s cells. This system was used to distinguish a model moderate pro-hapten isoeugenol (IE) and a model strong pre-hapten p-phenylenediamine (PPD) from irritant, salicylic acid (SA). Commonly evaluated metrics such as CD86, CD54, and IL-8 secretion were assessed, in concert with a 27-cytokine multi-plex screen and a functional chemotaxis assay. Data were analyzed with feature selection methods using ANOVA, hierarchical cluster analysis, and a support vector machine to identify the best molecular signature for sensitization. A panel consisting of IL-12, IL-9, VEGF, and IFN-γ predicted sensitization with over 90% accuracy using this co-culture system analysis. Thus, a multi-metric approach that has the potential to identify a molecular signature may be more predictive of contact sensitization.     

2013年乌鲁木齐地区部分CT机工作场所周围剂量当量率及质量控制检测

目的 了解2013年乌鲁木齐地区部分医疗机构CT机工作场所周围剂量水平,并进行质量控制检测,为放射防护工作提供科学依据.方法 对乌鲁木齐地区31台CT机进行质量控制检测,对CT机工作场所进行周围剂量当量率检测.结果 31台CT机工作场所周围剂量当量率检测合格率为96.77％,周围剂量当量率检测结果值为(0.19±0.17) μGy/h.质量控制检测合格率为93.55％,CTDIW的离散性最大,其后依次为重建层厚偏差、CT值(水)、均匀性、高对比分辨力、低对比可探测能力、定位光精度、噪声.结论 所监测的31台CT机质量性能符合国家标准要求,影像质量符合临床诊断需求,CT机工作场所的屏蔽效果满足防护要求.     

Effects of transmembrane region variability on cell surface expression and allorecognition of HLA-DP3

The functional relevance of polymorphisms outside the peptide binding groove of HLA molecules is poorly understood. Here we have addressed this issue by studying HLA-DP3, a common antigen relevant for functional matching algorithms of unrelated hematopoietic stem cell transplantation (HSCT) encoded by two transmembrane (TM) region variants, DPB1^*03:01 and DPB1^*104:01. The two HLA-DP3 variants were found at a overall allelic frequency of 10.4% in 201 volunteer stem cell donors, at a ratio of 4.2:1. No significant differences were observed in cell surface expression levels of the two variants on B lymphoblastoid cell lines (BLCL), primary B cells or monocytes. Three different alloreactive T cell lines or clones showed similar levels of activation marker CD107a and/or CD137 upregulation in response to HLA-DP3 encoded by DPB1^*03:01 and DPB1^*104:01, either endogenously on BLCL or after lentiveral-vector mediated transfer into the same cellular background. These data provide, for the first time, direct evidence for a limited functional role of a TM region polymorphism on expression and allorecognition of HLA-DP3 and are compatible with the notion that the two variants can be considered as a single functional entity for unrelated stem cell donor selection.     

Effect of X-ray beam energy and image reconstruction technique on computed tomography numbers of various tissue equivalent materials

IntroductionComputed tomography (CT) numbers are used in radiological diagnosis, attenuation correction and radiotherapy treatment planning. Modern CT scanners use iterative reconstruction methods instead of the traditional filtered back projection (FBP). Hence, the investigation of CT number accuracy with image reconstruction techniques and X-ray tube potential (kVp) used in CT is warranted. The aim of this study is to evaluate the effect of Sinogram Affirmed Iterative Reconstruction (SAFIRE) Technique and image acquisition at different tube potentials on CT numbers of different tissue equivalent materials.MethodsImages of the Computerised Imaging Reference System Model 062M Electron Density Phantom were acquired at different tube potentials and reconstructed using FBP and different strengths of SAFIRE. Average CT numbers, in circular regions of interest, and their standard deviations were used to investigate any dependence of CT numbers on tube potentials and/or image reconstruction technique using non-parametric statistical tests with p-values set at 0.05.ResultsStatistically significant differences in CT numbers were not observed (p > 0.091) between the different image reconstruction techniques. CT number of bone equivalent materials increased significantly (p < 0.015), by up to 400 Hounsfield Units, when tube potential was decreased. Such extent of CT number change over the tube potentials range used in this study may influence diagnostic outcomes in lung nodule, contrast enhanced and calcium score studies. For all other tissue equivalent materials, the CT number did not change significantly for different tube potentials. Linear relationship was observed between CT numbers and electron densities.ConclusionThe study concludes that the CT numbers of all tissues did not change significantly with image reconstruction methods. However, the CT numbers of bone equivalent materials increased with decreasing tube potentials, which may result in misrepresentation of clinical information obtained.Implications for practiceWhen CT images are used to extract quantitative parameters such as calcium score, to characterise lung nodules and contrast enhanced structures, the kVp used for image acquisition should be carefully selected to avoid any misrepresentation of clinical information.     

高能光源储存环及同步加速器屏蔽计算与探讨

目的验证和探讨在高能同步辐射光源辐射屏蔽计算中半经验公式和蒙特卡罗模拟方法的一致性和适用性。方法分别采用半经验公式和蒙特卡罗模拟独立计算单电子打靶时屏蔽体外产生的周围剂量当量。结果Jenkins半经验公式计算结果与蒙特卡罗模拟结果比值范围为111%~153%,Sakano半经验公式计算结果与蒙特卡罗模拟结果比值为201%。结论对单一屏蔽材料,半经验公式可简单、保守地完成对高能电子加速器的屏蔽计算。对于多种屏蔽材料,宜采用蒙特卡罗模拟方法。     

RBC、Ret-He与HbA2联合检测对地中海贫血的临床价值

目的:探讨小细胞或低色素人群中Ret-He和RBC在地中海贫血中的分布情况及联合HbA2对地中海贫血检测的价值。方法:选取本院2018年5月-2019年12月门诊检测出或住院的小细胞或低色素患者145例,将其分为地贫组(68例)及非地贫组(77例),并同时按贫血程度将患者分为非贫血、轻度贫血、中度贫血及重度贫血共4组,对患者进行Ret-He、RBC、RDW-CV及HbA2检测,比较各项参数的分布情况,并分析RBC、Ret-He与HbA2联合检测以辅助诊断地中海贫血的灵敏度特异度。结果:在小细胞或低色素患者中,根据贫血程度分级,Ret-He从非贫血组至重度贫血组逐渐下降(P<0.05);而RDW-CV则从轻度贫血组至重度贫血组逐渐上升(P<0.05);RBC及Ret-He在地贫组患者中均较非地贫组明显升高(P<0.05),而RDW-CV则在地贫组中较非地贫组明显降低(P<0.05);同时Ret-He在α-地贫中较β-地贫明显升高(P<0.05)。进行ROC曲线分析,Ret-He以19.25 pg为截断值,RBC以4.95×10^12/L为截断值时,联合HbA2,特异度为93.51%,灵敏度为66.18%,阳性预测值为90%,阴性预测值为75.189%。结论:在小细胞或低色素患者中,RBC、Ret-He及RDW-CV在地贫组及非地贫组的分布存在差异,并受贫血程度影响。加入Ret-He及RBC可提高小细胞或低色素患者依靠HbA2进行地中海贫血初筛时的特异度。     

Diets high in glycemic index and glycemic load are associated with an increased risk of metabolic syndrome among Korean women

Background and aimsAccurate estimation of the glycemic index (GI) and glycemic load (GL) of diets is essential when assessing health implications of dietary GI and GL. The present study aimed to estimate dietary GI and GL utilizing the updated GI tables with a large number of new, reliable GI values and assess their associations with metabolic syndrome among Korean adults.Methods and resultsWe analyzed data from 3317 men and 6191 women for this cross-sectional study. Dietary intake was assessed with a validated food frequency questionnaire. Metabolic syndrome and its components were defined based on the harmonized criteria with Korean-specific cutoffs for waist circumference. Multivariate logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Compared with women in the lowest quintiles of energy-adjusted dietary GI and GL, women in the highest quintiles had significantly greater risks of metabolic syndrome (GI, OR = 1.56, 95% CI = 1.18–2.06; GL, OR = 1.80, 95% CI = 1.27–2.57), elevated blood pressure, reduced high-density lipoprotein cholesterol (HDL-C, both GI and GL), elevated triglycerides (GI only), elevated waist circumference, and elevated fasting glucose (GL only). Among men, no significant association was noted except for a higher risk of reduced HDL-C (OR = 1.59, 95% CI = 1.01–2.29) in the highest quintile of energy-adjusted dietary GI than in the lowest quintile.ConclusionOur findings suggest that dietary GI and GL are positively associated with metabolic syndrome risk among women, but not men, in Korea.