计算机辅助超声诊断提高卵巢癌诊断的准确性

目的:评估应用计算机辅助阴式超声诊断卵巢癌是否优于单独阴式超声诊断。方法:收集2013年9月-2015年3月在我院进行手术切除的卵巢肿块患者的术前阴式超声(TVS)图像资料,共124例(病理诊断良性80例,恶性44例),平均年龄54.2±9.7岁。建立的图像样本库,每名患者取4幅超声图像,共有496幅图像被分析。首先对图片库内的超声图像进行多模式序列超声识别系统的处理,应用灰度共生矩阵法,获得肿块的各种特征,将感兴趣区域分类为正常组织,良性肿块和恶性肿瘤。两名超声医生人工肉眼对卵巢肿块的原始阴式超声图片进行分析诊断,随后两名医师对计算机辅助诊断(CAD)处理后的图片再次分析诊断,以病理诊断为金标准,利用ROC曲线下肿块区域的面积参数评价单独TVS和TVS结合CAD诊断卵巢癌的准确度差异。比较应用CAD前后的特异性、敏感性、阳性预测值,阴性预测值等指标的差异。结果:TVS结合CAD诊断准确度高于单独TVS,单独TVS诊断ROC曲线下面积(Az)为0.791,95%可信区间[0.725-0.857],TVS结合CAD诊断Az为0.927,95%可信区间[0.883-0.970];TVS结合CAD组诊断卵巢癌的精确度(0.774 vs 0.919,P0.05)、特异性(0.738 vs 0.933,P0.05)及阳性预测值(0.650 vs 0.889,P0.05)较单独TVS诊断明显提高。结论:计算机辅助诊断技术可以辅助超声医师提高卵巢癌诊断的准确度。     

Accuracy and Reliability of Pallor for Detecting Anaemia: A Hospital-Based Diagnostic Accuracy Study

Background

Anaemia is a common disorder. Most health providers in resource poor settings rely on physical signs to diagnose anaemia. We aimed to determine the diagnostic accuracy of pallor for anaemia by using haemoglobin as the reference standard.

Methodology/Principal Findings

In May 2007, we enrolled consecutive patients over 12 years of age, able to consent and willing to participate and who had a haemoglobin measurement taken within a day of assessment of clinical pallor from outpatient and medicine inpatient department of a teaching hospital. We did a blind and independent comparison of physical signs (examination of conjunctivae, tongue, palms and nailbed for pallor) and the reference standard (haemoglobin estimation by an electronic cell counter). Diagnostic accuracy was measured by calculating likelihood ratio values and 95% confidence intervals (CI) at different haemoglobin thresholds and area under the receiver operating characteristic curve. Two observers examined a subset of patients (n = 128) to determine the inter-observer agreement, calculated by kappa statistics. We studied 390 patients (mean age 40.1 [SD 17.08] years); of whom 48% were women. The haemoglobin was <7 g/dL in 8% (95% confidence interval, 5, 10) patients; <9 g/dL in 21% (17, 26) patients and <12 g/dL in 64% (60, 70) patients. Among patients with haemoglobin <7 g/dL, presence of severe tongue pallor yielded a LR of 9.87 (2.81, 34.6) and its absence yielded a LR of 0. The tongue pallor outperformed other pallor sites and was also the best discriminator of anaemia at haemoglobin thresholds of 7 g/dL and 9 g/dL (area under the receiver operating characteristic curves (ROC area  = 0.84 [0.77, 0.90] and 0.71[0.64, 0.76]) respectively. The agreement between the two observers for detection of anaemia was poor (kappa values  = 0.07 for conjunctival pallor and 0.20 for tongue pallor).

Conclusions/Significance

Clinical assessment of pallor can rule out and modestly rule in severe anaemia.     

Diagnostic Accuracy of Five Serologic Tests for Strongyloides stercoralis Infection

Background

The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference (“gold”) standard.

Methods

The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests).

Results

According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2–96.9), followed by IVD-ELISA (92.3%, 87.7–96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9–100), followed by IVD-ELISA (97.4%, 95.5–99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIE-LIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains ≥70% sensitivity.

Conclusions

NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.     

Diagnostic Accuracy of CT-Guided Transthoracic Needle Biopsy for Solitary Pulmonary Nodules

To evaluate the diagnostic accuracy of computed tomography (CT)-guided percutaneous lung biopsy for solitary pulmonary nodules. Three hundred and eleven patients (211 males and 100 females), with a mean age of 59.6 years (range, 19–87 years), who were diagnosed with solitary pulmonary nodules and underwent CT-guided percutaneous transthoracic needle biopsy between January 2008 and January 2014 were reviewed. All patients were confirmed by surgery or the clinical course. The overall diagnostic accuracy and incidence of complications were calculated, and the factors influencing these were statistically evaluated and compared. Specimens were successfully obtained from all 311 patients. A total of 217 and 94 cases were found to be malignant and benign lesions, respectively, by biopsy. Two hundred and twenty-five (72.3%) carcinomas, 78 (25.1%) benign lesions, and 8 (2.6%) inconclusive lesions were confirmed by surgery and the clinical course. The diagnostic accuracy, sensitivity, and specificity of CT-guided percutaneous transthoracic needle biopsy were 92.9%, 95.3%, and 95.7%, respectively. The incidences of pneumothorax and self-limiting bleeding were 17.7% and 11.6%, respectively. Taking account of all evidence, CT-guided percutaneous lung biopsy for solitary pulmonary nodules is an efficient, and safe diagnostic method associated with few complications.     

Rapid Diagnostic Tests for Dengue Virus Infection in Febrile Cambodian Children: Diagnostic Accuracy and Incorporation into Diagnostic Algorithms

BackgroundDengue virus (DENV) infection is prevalent across tropical regions and may cause severe disease. Early diagnosis may improve supportive care. We prospectively assessed the Standard Diagnostics (Korea) BIOLINE Dengue Duo DENV rapid diagnostic test (RDT) to NS1 antigen and anti-DENV IgM (NS1 and IgM) in children in Cambodia, with the aim of improving the diagnosis of DENV infection.ConclusionsThe DENV RDT had low sensitivity for the diagnosis of DENV infection. The high co-prevalence of infections in our cohort indicates the need for a broad microbiological assessment of non-localised febrile illness in these children.     

Accuracy analysis of multiple structure alignments

Protein structure alignment methods are essential for many different challenges in protein science, such as the determination of relations between proteins in the fold space or the analysis and prediction of their biological function. A number of different pairwise and multiple structure alignment (MStA) programs have been developed and provided to the community. Prior knowledge of the expected alignment accuracy is desirable for the user of such tools. To retrieve an estimate of the performance of current structure alignment methods, we compiled a test suite taken from literature and the SISYPHUS database consisting of proteins that are difficult to align. Subsequently, different MStA programs were evaluated regarding alignment correctness and general limitations. The analysis shows that there are large differences in the success between the methods in terms of applicability and correctness. The latter ranges from 44 to 75% correct core positions. Taking only the best method result per test case this number increases to 84%. We conclude that the methods available are applicable to difficult cases, but also that there is still room for improvements in both, practicability and alignment correctness. An approach that combines the currently available methods supported by a proper score would be useful. Until then, a user should not rely on just a single program.     

Comparison of Diagnostic Accuracy of Biomarkers With Pooled Assessments

New biomarkers are frequently being developed in laboratory settings for the early diagnosis of diseases. However, the assay can be so expensive to assess in some cases that the evaluation of a large number of assays becomes unfeasible. Under this setting pooling biospecimens becomes an appealing alternative. In this paper, we present the methodology to allow for general pooling strategies and different data structures, which include balanced and unbalanced pooling cases. An estimate of the area under the ROC curve of a single biomarker with its asymptotic mean and variance is provided. Furthermore, we develop a test statistic for comparing the areas under the ROC curves of two biomarkers. The methods are illustrated with data from a study evaluating biomarkers for coronary heart disease.     

Evaluation of the Diagnostic Accuracy of Prototype Rapid Tests for Human African Trypanosomiasis

BackgroundDiagnosis of human African trypanosomiasis (HAT) remains a challenge both for active screening, which is critical in control of the disease, and in the point-of-care scenario where early and accurate diagnosis is essential. Recently, the first field deployment of a lateral flow rapid diagnostic test (RDT) for HAT, “SD BIOLINE HAT” has taken place. In this study, we evaluated the performance of “SD BIOLINE HAT” and two new prototype RDTs.Conclusions/SignificanceBoth “SD BIOLINE HAT” and the prototype devices performed comparably well to one another and also to the published performance range of the card agglutination test for trypanosomiasis in sensitivity and specificity. The performance of individual antigens enabled us to predict that an all-recombinant antigen RDT can be developed with an accuracy equivalent to “ SD BIOLINE HAT.” Such an RDT would have advantages in simplified manufacture, lower unit cost and assured reproducibility.     

Diagnostic Accuracy of Early Radiology in Acute Gastrointestinal Haemorrhage

The accuracy of early radiology in patients with acute gastrointestinal haemorrhage has been studied by a comparison of the radiological opinion with the established diagnosis. A full examination has proved safe and uncomplicated with a high degree of accuracy and no false-positive results.Analysis of the errors shows that the presence of residue discourages the radiologist from making the correct diagnosis, and modification of the standard bariummeal technique may be needed to overcome this difficulty.     

Diagnostic Accuracy and Optimal Use of Three Tests for Tuberculosis in Live Badgers

Background

Accurate diagnosis of tuberculosis (TB) due to infection with Mycobacterium bovis is notoriously difficult in live animals, yet important if we are to understand the epidemiology of TB and devise effective strategies to limit its spread. Currently available tests for diagnosing TB in live Eurasian badgers (Meles meles) remain unvalidated against a reliable gold standard. The aim of the present study was to evaluate the diagnostic accuracy and optimal use of three tests for TB in badgers in the absence of a gold standard.

Methodology/Principal Findings

A Bayesian approach was used to evaluate the diagnostic accuracy and optimal use of mycobacterial culture, gamma-interferon assay and a commercially available serological test using multiple samples collected from 305 live wild badgers. Although no single test was judged to be sufficiently sensitive and specific to be used as a sole diagnostic method, selective combined use of the three tests allowed guidelines to be formulated that allow a diagnosis to be made for individual animals with an estimated overall accuracy of 93% (range: 75% to 97%). Employing this approach in the study population of badgers resulted in approximately 13 out of 14 animals having their true infection status correctly classified from samples collected on a single capture.

Conclusions/Significance

This method of interpretation represents a marked improvement on the current procedure for diagnosing M. bovis infection in live badgers. The results should be of use to inform future test and intervention strategies with the aim of reducing the incidence of TB in free-living wild badger populations.     

不同包埋材料和加热方法对镍铬金属全冠精度的影响研究

目的:研究快速和慢速包埋方法对铸造全冠精度的影响.方法:在同一模具上制作36个熔模冠,随机分为6组,分别用德国BEGO、南昌飞马、洛阳北苑磷酸盐包埋材料进行快速包埋和慢速包埋.测定各组铸造冠的边缘浮升量.结果:慢速包埋组铸造冠的平均边缘浮升量为41.67±3.94?m,快速包埋组铸造冠的平均边缘浮升量为96.63±7.46?m,两组间的差别有统计学意义.结论:慢速包埋方法比快速包埋方法制作的铸造冠边缘浮升量小,铸造精度高.     

外泌体作为疾病诊断标志物及药物载体的应用前景

作为一种纳米级别的囊泡,外泌体的相关研究近年来逐渐成为热点。外泌体来源于细胞内的多囊泡胞内体,经由细胞膜释放到细胞外。由于来自特定细胞类型的外泌体含有多种特异性的蛋白质和microRNA,使其成为了可以广泛用于疾病诊断及预后的新型生物标志物。相较于其他外源性药物载体,外泌体具有更低的免疫原性,并能够靶向作用于病变细胞。这使得由细胞天然产生或经过人工改造的外泌体作为一种新兴的药物载体具有良好的发展前景。特别是近几年,外泌体在临床应用领域的发展潜力不断获得拓展,针对肿瘤、糖尿病、心脑血管疾病、神经退行性病变等重大疾病,以外泌体为基础的疾病诊断和药物的研发都取得了快速的进步。本篇综述重点介绍了外泌体作为一种生物标志物在疾病诊断和预后中的应用,同时阐述了外泌体作为一种新兴的药物载体所具有的优势以及存在的问题。     

Diagnostic Accuracy of the Leishmania OligoC-TesT and NASBA-Oligochromatography for Diagnosis of Leishmaniasis in Sudan

Background

The Leishmania OligoC-TesT and NASBA-Oligochromatography (OC) were recently developed for simplified and standardised molecular detection of Leishmania parasites in clinical specimens. We here present the phase II evaluation of both tests for diagnosis of visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and post kala-azar dermal leishmaniasis (PKDL) in Sudan.

Methodology

The diagnostic accuracy of the tests was evaluated on 90 confirmed and 90 suspected VL cases, 7 confirmed and 8 suspected CL cases, 2 confirmed PKDL cases and 50 healthy endemic controls from Gedarif state and Khartoum state in Sudan.

Principal Findings

The OligoC-TesT as well as the NASBA-OC showed a sensitivity of 96.8% (95% CI: 83.8%–99.4%) on lymph node aspirates and of 96.2% (95% CI: 89.4%–98.7%) on blood from the confirmed VL cases. The sensitivity on bone marrow was 96.9% (95% CI: 89.3%–99.1%) and 95.3% (95% CI: 87.1%–98.4%) for the OligoC-TesT and NASBA-OC, respectively. All confirmed CL and PKDL cases were positive with both tests. On the suspected VL cases, we observed a positive OligoC-TesT and NASBA-OC result in 37.1% (95% CI: 23.2%–53.7%) and 34.3% (95% CI: 20.8%–50.9%) on lymph, in 72.7% (95% CI: 55.8%–84.9%) and 63.6% (95% CI: 46.6%–77.8%) on bone marrow and in 76.9% (95% CI: 49.7%–91.8%) and 69.2% (95% CI: 42.4%–87.3%) on blood. Seven out of 8 CL suspected cases were positive with both tests. The specificity on the healthy endemic controls was 90% (95% CI: 78.6%–95.7%) for the OligoC-TesT and 100% (95% CI: 92.9%–100.0%) for the NASBA-OC test.

Conclusions

Both tests showed high sensitivity on lymph, blood and tissue scrapings for diagnosis of VL, CL and PKDL in Sudan, but the specificity for clinical VL was significantly higher with NASBA-OC.