Ten Versus Five Polymorphonuclear Leukocytes as Threshold in Frozen Section Tests for Periprosthetic Infection: A Meta-Analysis

We objectively appraised available evidence regarding the threshold for the number of polymorphonuclear leukocytes required in frozen section tests used to diagnose periprosthetic infection. Pooled summary estimates for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio (OR) were compared for ten and five polymorphonuclear leukocytes per high power field as the threshold. The total cohort included 1011 patients and the rate of infection was 19.2%. Although there was no difference in sensitivity or diagnostic OR, specificity was significantly higher for ten than for five polymorphonuclear leukocytes per high power field (p = 0.007) In sum, a threshold of 10 polymorphonuclear leukocytes is better for diagnosing periprosthetic infections.     

Likelihood ratios increase diagnostic certainty in pulmonary embolism

Pulmonary embolism (PE) is a difficult diagnosis to confirm. The choice of tests has led to a myriad of algorithms. Diagnostic uncertainty can be quantified by the application of the tests' likelihood ratios (LR). Positive and negative LR enable the conversion of a pretest to a post-test probability, given a positive and negative test result, respectively. Thus, a pretest probability of <17% and a negative D-dimer with a negative LR of 0.05 (sensitivity 98%, specificity 40%) lead to a post-test probability of PE of <1%. Ventilation perfusion (V/Q) scans with a normal, very low, low, intermediate and high probability result have an LR of 0, 0.125, 0.25, 1 and 17, respectively. Also, patients with a V/Q scan result other than normal or high probability still have a post-test probability of PE from 3 to 65%. Positive and negative computed tomography pulmonary angiograms (CTPA) have an LR of 8.6 and 0.06, respectively (sensitivity 95%, specificity 89%). Patients with a high pretest probability and negative CTPA again still have a post-test probability of more than 10%. However, as the post-test probability after one test becomes the pretest probability for the next, test results used cumulatively progressively narrow the gap to a final diagnosis. The post-test probability after a D-dimer, V/Q scan, CTPA, leg ultrasound or pulmonary angiography, alone or in any combination or in any order, can be calculated using their LR. Use of LR thus assists in the precise interpretation of test results, such as in complex algorithms for PE.     

Critical data‐based re‐evaluation of minocycline as a putative specific microglia inhibitor

Minocycline, a second generation broad‐spectrum antibiotic, has been frequently postulated to be a “microglia inhibitor.” A considerable number of publications have used minocycline as a tool and concluded, after achieving a pharmacological effect, that the effect must be due to “inhibition” of microglia. It is, however, unclear how this “inhibition” is achieved at the molecular and cellular levels. Here, we weigh the evidence whether minocycline is indeed a bona fide microglia inhibitor and discuss how data generated with minocycline should be interpreted. GLIA 2016;64:1788–1794     

A new T‐cell activation mode for suboptimal doses of antigen under the full activation of T cells with different specificity

Loss of tolerance for autoantigens is a common feature in autoimmune diseases. Bystander T‐cell activation is the activation of T cells to produce functional changes through TCR‐independent stimulation. Although bystander activation may be related to tolerance loss to multiple autoantigens, the activation mechanism of T cells directed to an autoantigen with limited amount is not clear. We investigated an activation mode of T cells (designated as “associator T cells”) directed to a suboptimal dose of cognate antigen X in the presence of fully activated T cells (designated as “responder T cells”) directed to an optimal dose of antigen Y. In in vitro coculture, the activation of associator T cells was dependent on the presentation of antigen X, and soluble factors from activated responder T cells were not sufficient. Therefore, we conclude this activation mode is different from bystander activation and named it “extended antigen priming (EAP)”. T cells with EAP showed a different phenotype compared to conventionally primed cells, suggesting the unique nature of EAP. Intriguingly, EAP was dependent on the CD40–CD40L signaling pathway. Thus, the EAP model is a T‐cell activation mode for suboptimal dose of antigen and presumably related to the immune response to autoantigens in autoimmune status.     

钆塞酸二钠在肝脏MRI增强扫描应用中的护理

目的：探讨肝胆特异性对比剂钆塞酸二钠(Gd-EOB-DTPA)在肝脏MRI增强扫描应用中的护理措施。方法针对Gd-EOB-DTPA的使用注意事项和MRI增强检查的特殊要求,对288例应用该对比剂行肝脏MRI增强扫描的患者从心理护理、检查前准备、检查中配合、检查后不良反应处理等方面进行护理干预。结果4例(1.4%)患者呼吸配合欠佳,其中1例图像伪影较多,影响观察及诊断,3例图像伪影较小,对图像质量的影响不大,其余284例患者(98.6%)患者顺利完成检查,取得高质量的图像效果。288例患者中,1例患者检查后出现颜面部潮红,2例患者出现恶心,无呕吐,其余患者在检查过程中及检查后均无不适。结论 Gd-EOB-DTPA应用于肝脏MRI增强扫描中具有安全、有效的优点,提高图像质量、实施综合护理措施是检查成功的重要因素。     

结核分枝杆菌特异性蛋白片段Rv3388和6种特异抗原在结核抗体检测中的应用价值

目的 对结核分枝杆菌( MTB) PE家族的所有成员的结构进行分析,预测其抗原表位,截取Rv3388蛋白的优势抗原片段,对重组Rv3388蛋白及其它6种MTB特异性抗原进行评估,探讨不同结核特异性抗原与血清抗体的反应模式,评价血清学检测在结核病诊断中的价值. 方法 利用基因合成技术重叠延伸PCR扩增Rv3388蛋白637~731位的编码基因片段, 原核表达并纯化重组蛋白pET32a/Rv3388637-731 ,将纯化的重组蛋白免疫BALB/c小鼠,采用间接ELISA法对该抗血清进行免疫原性分析. 同时对这7种MTB特异性蛋白的特异性及敏感性进行评价. 结果 重组蛋白pET32a/Rv3388637-731在大肠杆菌中的表达量占全菌蛋白的80%,ELISA显示有较强的免疫原性. 7 种 MTB特异性抗原具有不同的反应模式,单个抗原检测敏感性较差. 结论 对MTB PE家族的蛋白结构分析,表达并纯化重组蛋白pET32a/ Rv3388637-731 ,7种蛋白在血清抗体检测中具有抗原互补性,不同抗原与机体反应存在不同反应模式,提高结核抗体检测敏感性应多种抗原联合检测.     

The validity of military screening for mental health problems: diagnostic accuracy of the PCL,K10 and AUDIT scales in an entire military population

Depression, alcohol use disorders and post‐traumatic stress disorder (PTSD) are serious issues among military personnel due to their impact on operational capability and individual well‐being. Several military forces screen for these disorders using scales including the Kessler Psychological Distress Scale (K10), Alcohol Use Disorders Identification Test (AUDIT), and Post‐traumatic Stress Disorder Checklist (PCL). However, it is unknown whether established cutoffs apply to military populations. This study is the first to test the diagnostic accuracy of these three scales in a population‐based military cohort. A large sample of currently‐serving Australian Defence Force (ADF) Navy, Army and Air Force personnel (n = 24,481) completed the K10, AUDIT and PCL‐C (civilian version). Then, a stratified sub‐sample (n = 1798) completed a structured diagnostic interview detecting 30‐day disorder. Data were weighted to represent the ADF population (n = 50,049). Receiver operating characteristic (ROC) analyses suggested all three scales had acceptable sensitivity and specificity, with areas under the curve from 0.75 to 0.93. AUDIT and K10 screening cutoffs closely paralleled established cutoffs, whereas the PCL‐C screening cutoff resembled that recommended for US military personnel. These self‐report scales represent a cost‐effective and clinically‐useful means of screening personnel for disorder. Military populations may need lower cutoffs than civilians to screen for PTSD. Copyright © 2014 John Wiley & Sons, Ltd.