Cord serum IgE in relation to family history and as predictor of atopic disease in early infancy

Cord serum IgE was assayed by particle counting immunoassay (PACIA) in an unselected series of European newborns (n = 190; geom mean = 0.37 IU/ml) and a cutoff limit established (≥ 1.20 IU/ml) for prediction of atopy. At control follow-up by questionnaire 18 months after birth, 38 infants (20.0%) had developed definite (9.5%) or probable (10.5%) atopy with a significant predominance of boys ( P < 0.03). Infants with a positive immediate family history (IFH) had a higher risk of developing atopy ( P < 0.0025) and also had a higher incidence of elevated cord IgE ( P < 0.02) than infants with a negative IFH. Maternal atopy influenced cord IgE levels significantly ( P < 0.00005), whereas paternal atopy did not ( P = 0.23). No fetal IgE antibodies against five common allergens could be demonstrated in 36 cord sera tested. Breast-feeding for 3 months was not sufficient to prevent atopic symptoms. The predictive value of cord IgE was high since 26 of 36 newborns (positive predictive value = 72.2 %) with elevated cord IgE had developed atopic symptoms before follow-up. Of the 38 infants who developed atopic symptoms, 26 had elevated cord IgE (sensitivity = 68.4%) compared to only 10 (6.6%) of the 152 atopy-free infants (P < 0.00005). The data indicate that elevated cord IgE as determined by PACIA is a good predictor of early-onset atopy, better than family history ( P < 0.008), and that primarily maternal atopy seems to affect fetal IgE synthesis.     

从HCV蛋白一级结构预测其C,E,NS5区的CD_4~ T细胞抗原位点

我们根据ＣＤ４＋Ｔ细胞识别抗原位点的物理化学和生物学特征，设计了一个具有查找两亲性螺旋状结构（ａｍｐｈｉｐａｔｈｉｃｈｅｌｉｘｓｔｒｕｃｔｕｒｅ）肽段功能的计算机程序。用该程序对ＨＣＶ－１型病毒Ｃ、Ｅ（Ｅ１、Ｅ２／ＮＳ１）、ＮＳ５蛋白一级结构进行分析，发现这些蛋白区存在ＣＤ４＋Ｔ细胞识别位点。此结果支持了ＣＤ４＋Ｔ细胞对ＨＣＶＣ，Ｅ，ＮＳ５区可发生增殖反应的结论。提示该程序可作为一种预测ＣＤ４＋Ｔ细胞识别ＨＣＶ抗原位点的方法。     

Analysis of mid-trimester corticotrophin-releasing hormone and alpha-fetoprotein concentrations for predicting pre-eclampsia

The aims of this study were firstly to examine if corticotrophin-releasing hormone (CRH) concentrations in maternal plasma were significantly elevated in Chinese pregnancies complicated by pre-eclampsia, secondly to assess if this elevation could be detected in the mid-trimester before onset of clinical signs of the disease, and thirdly to evaluate the performance of using maternal CRH and/or alpha-fetoprotein (AFP) concentrations in the mid-trimester for prediction of pre-eclampsia. The first part of this study was tested in a cohort of 39 subjects. The CRH concentrations were significantly elevated in pregnant women complicated by pre-eclampsia. The second and third parts of the study involved a different cohort of 1021 subjects. Both CRH and AFP concentrations in the mid-trimester were significantly elevated in those who subsequently developed pre-eclampsia. However, when used for prediction of pre-eclampsia, neither the CRH nor AFP concentrations alone in the mid-trimester had strong predictive value. Although the combination of both tests improved the detection rate compared to the use of CRH alone, the small increase in the likelihood ratio from 1.9 to 2.6 did not suggest that the combination would be of great clinical value.     

H-2~b和H-2~d单体型小鼠MHCI类分子结合的HFRSV蛋白抗原表位的预测

本文通过对Ｈ－２ｂ和Ｈ－２ｄ单体型小鼠主要组织相容性抗原Ｉ类分子结合抗原肽的分析，建立了一个计算机预测模型，并对肾综合征出血热病毒核蛋白（ＮＰ）及囊膜糖蛋白Ｇ１和Ｇ２可与Ｂａｌｂ／ｃ小鼠（Ｈ－２ｄ）和Ｃ５７ＢＬ／６（Ｈ－２ｂ）小鼠ＭＨＣＩ类分子相结合的抗原表位进行了分析，预测出可分别与Ｈ－２Ｋｂ，Ｈ－２Ｄｂ，Ｈ－２Ｋｄ，Ｈ－２Ｄｄ和Ｈ－２Ｌｄ结合的核蛋白表位，依此各有７，１４，４，０和８个；囊膜糖蛋白Ｇ１＋Ｇ２的表位，依次有１４，１９，２７，２和４４个。     

Abdominal lean muscle is associated with lower mortality among kidney waitlist candidates

Morphometric assessments, such as muscle density and body fat distribution, have emerged as strong predictors of cardiovascular risk and postoperative morbidity and mortality. To date, no study has examined morphometric mortality risk prediction among kidney transplant (KT) candidates. KT candidates, waitlisted 2008‐2009, were identified (n=96) and followed to the earliest of transplant, death, or administrative end of study. Morphometric measures, including abdominal adipose tissue, paraspinous and psoas muscle composition, and aortic calcification, were measured from CTs. Risk of waitlist mortality was examined using Cox proportional hazard regression. On adjusted analyses, radiologic measures remained independently and significantly associated with lower waitlist mortality; the addition of radiologic measures significantly improved model predictive ability over models containing traditional risk factors alone (net reclassification index: 0.56, 95% CI: 0.31‐0.75). Higher psoas muscle attenuation (indicative of leaner muscle) was associated with decreased risk of death (aHR: 0.93, 95% CI: 0.91‐0.96, P<.001), and for each unit increase in lean paraspinous volume, there was an associated 2% decreased risk for death (aHR: 0.98, 95% CI: 0.96‐0.99, P=.03). Radiologic measures of lean muscle mass, such as psoas muscle attenuation and paraspinous lean volume, may improve waitlist mortality risk prediction and candidate selection.     

降钙素原及C反应蛋白联合检测在急性重度胰腺炎发生风险中的预测价值

目的探讨早期降钙素原(PCT)及C反应蛋白(CRP)水平在急性重度胰腺炎发生风险中的预测价值。方法收集2013年1月至2015年12月在我院治疗的68例急性胰腺炎患者为研究对象进行回顾性研究。所有病例依照2013版中国急性胰腺炎诊疗指南将患者划分为轻度胰腺炎组(对照组),以及重度胰腺炎组(观察组)。通过t检验、Logistic回归以及ROC曲线分析起病24小时内的PCT及CRP水平与重度胰腺炎发生的相关性。结果观察组中PCT、CRP平均水平高于对照组(P0.001),Logistic回归分析得到PCT、CRP的OR值分别为1.41、1.125,两者95%置信区间均1,PCT、CRP均为重度胰腺炎的危险因素,可联合对重度胰腺炎发生风险进行预测。而ROC曲线提示PCT对重度胰腺炎预测敏感性及准确性要优于CRP。结论通过早期检测血清PCT和CRP水平能够对急性胰腺炎患者的病情严重程度提供帮助,而对重度胰腺炎早期综合治疗具有一定的临床指导价值。     

Comparisons of risk prediction methods using nested case‐control data

Using both simulated and real datasets, we compared two approaches for estimating absolute risk from nested case‐control (NCC) data and demonstrated the feasibility of using the NCC design for estimating absolute risk. In contrast to previously published results, we successfully demonstrated not only that data from a matched NCC study can be used to unbiasedly estimate absolute risk but also that matched studies give better statistical efficiency and classify subjects into more appropriate risk categories. Our result has implications for studies that aim to develop or validate risk prediction models. In addition to the traditional full cohort study and case‐cohort study, researchers designing these studies now have the option of performing a NCC study with huge potential savings in cost and resources. Detailed explanations on how to obtain the absolute risk estimates under the proposed approach are given. Copyright © 2016 John Wiley & Sons, Ltd.     

The use of repeated blood pressure measures for cardiovascular risk prediction: a comparison of statistical models in the ARIC study

Many prediction models have been developed for the risk assessment and the prevention of cardiovascular disease in primary care. Recent efforts have focused on improving the accuracy of these prediction models by adding novel biomarkers to a common set of baseline risk predictors. Few have considered incorporating repeated measures of the common risk predictors. Through application to the Atherosclerosis Risk in Communities study and simulations, we compare models that use simple summary measures of the repeat information on systolic blood pressure, such as (i) baseline only; (ii) last observation carried forward; and (iii) cumulative mean, against more complex methods that model the repeat information using (iv) ordinary regression calibration; (v) risk‐set regression calibration; and (vi) joint longitudinal and survival models. In comparison with the baseline‐only model, we observed modest improvements in discrimination and calibration using the cumulative mean of systolic blood pressure, but little further improvement from any of the complex methods. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.