Alternative Confidence Interval Methods Used in the Diagnostic Accuracy Studies.

PubMed

Erdoğan, Semra; Gülhan, Orekıcı Temel

2016-01-01

Background/Aim. It is necessary to decide whether the newly improved methods are better than the standard or reference test or not. To decide whether the new diagnostics test is better than the gold standard test/imperfect standard test, the differences of estimated sensitivity/specificity are calculated with the help of information obtained from samples. However, to generalize this value to the population, it should be given with the confidence intervals. The aim of this study is to evaluate the confidence interval methods developed for the differences between the two dependent sensitivity/specificity values on a clinical application. Materials and Methods. In this study, confidence interval methods like Asymptotic Intervals, Conditional Intervals, Unconditional Interval, Score Intervals, and Nonparametric Methods Based on Relative Effects Intervals are used. Besides, as clinical application, data used in diagnostics study by Dickel et al. (2010) has been taken as a sample. Results. The results belonging to the alternative confidence interval methods for Nickel Sulfate, Potassium Dichromate, and Lanolin Alcohol are given as a table. Conclusion. While preferring the confidence interval methods, the researchers have to consider whether the case to be compared is single ratio or dependent binary ratio differences, the correlation coefficient between the rates in two dependent ratios and the sample sizes.

Improved Specificity for Detection of Mycobacterium bovis in Fresh Tissues Using IS6110 Real-time PCR

USDA-ARS?s Scientific Manuscript database

Background: Culture of M. bovis from diagnostic specimens is the gold standard for bovine tuberculosis diagnostics in the US. Detection of M. bovis by PCR in tissue homogenates may provide a simple, rapid method to complement diagnostic culture. A significant impediment to PCR based assays on tissue...

Evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia.

PubMed

Yimer, Mulat; Hailu, Tadesse; Mulu, Wondemagegn; Abera, Bayeh

2015-12-26

Although the sensitivity of Wet mount technique is questionable, it is the major diagnostic technique for routine diagnosis of intestinal parasitosis in Ethiopia. Therefore, the aim of this study was the evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia. A cross sectional study was conducted from May to June 2013. Single stool sample was processed for direct, Formol ether concentration (FEC) and Kato Katz methods. The sensitivity and negative predictive value (NPV) of diagnostic tests were calculated in terms of the "Gold" standard method (the combined result of the three methods altogether). A total of 422 school age children were participated in this study. The prevalence of intestinal parasites was high (74.6%) with Kato Katz technique. The sensitivity of Wet mount, FEC and Kato Katz tests against the Gold standard test was 48.9, 63.1 and 93.7%, respectively. Kato Katz technique revealed a better NPV 80.4 (80.1-80.6) as compared to the Wet mount (33.7%) and FEC techniques (41.3%). In this study, the Kato Katz technique outperformed the other two methods but the true values for sensitivity, specificity and diagnostic values are not known. Moreover, it is labor intensive and not easily accessible. Hence, it is preferable to use FEC technique to complement the Wet mount test.

Standardization of Epitopes for Human Chorionic Gonadotropin (hCG) Immunoassays.

PubMed

Berger, Peter; Lapthorn, Adrian J

2016-01-01

hCG and its variants are markers for pregnancy tests, pregnancyrelated complications, trophoblastic diseases, pre-natal screening of Down's syndrome and doping controls. Strong demands are imposed on diagnostic methods by the dynamic changes in the absolute and relative levels of hCG protein backbone variants and glycosylation isoforms in serum and urine during development of pregnancy or the progression/remission of tumors. Observed differences in the results between commercial diagnostic immunoassays reflect the unequal molar recognition of the different metabolic hCG variants, in particular the hCG beta core fragment (hCGβcf), by the diagnostic antibodies (Abs), as their epitopes are not standardized, and the fact that suboptimal hCG standards are used. To rapidly characterize Abs by their epitope recognition and specificity to evaluate their suitability for diagnostic immunoassays a procedure of comparative epitope mapping has been developed using epitope-defined reference Abs. Comparative epitope mapping of diagnostic Abs will provide the basis for the standardization of diagnostic antigenic domains/epitopes and consequently for improved reliability of hCG measurements. Diagnostic first line assays likely consist of pairs of Abs that recognize specific epitopes at the top of the neighboring peptide loops 1 and 3 (Ł1+3) and the cystine knot (ck) of hCGβ, respectively. In future, significant improvements of reliability, robustness and comparability of the results of immunoassays for complex glycoproteins such as hCG will be achieved by the use (i) of standardized diagnostic Abs against welldefined epitopes and (ii) of the new International Standards for hCG and for five hCG variants established by WHO, that are calibrated in molar (SI) units.

Towards a Theory of Diagnosis in Second and Foreign Language Assessment: Insights from Professional Practice across Diverse Fields

ERIC Educational Resources Information Center

Alderson, J. Charles; Brunfaut, Tineke; Harding, Luke

2015-01-01

Diagnostic language assessment has received increased research interest in recent years, with particular attention on methods through which diagnostic information can be gleaned from standardized proficiency tests. However, diagnostic procedures in the broader sense have been inadequately theorized to date, with the result that there is still…

The prevalence of depressive symptoms in frontotemporal dementia: a meta-analysis.

PubMed

Chakrabarty, Trisha; Sepehry, Amir A; Jacova, Claudia; Hsiung, Ging-Yuek Robin

2015-01-01

Depression is common in Alzheimer's and vascular dementia and is associated with poorer outcomes; however, less is known about the impact of depression on frontotemporal dementia (FTD). Here, we conducted a meta-analysis of diagnostic methods and the prevalence of depressive symptoms in FTD. PubMed, EMBASE and PsychINFO were queried for 'depression' and/or 'depressive mood' in behavioral- and language-variant FTD. The prevalence and diagnosis of depressive symptoms were extracted from relevant studies and the results pooled using a random-effects model. We included 29 studies in this meta-analysis, with sample sizes ranging from 3 to 73 (n = 870). The omnibus estimated event rate of depressed mood was 0.334 (33%; 95% CI: 0.268-0.407). Symptoms were most commonly assessed via standardized neuropsychiatric rating scales, with other methods including subjective caregiver reports and chart reviews. The study results were heterogeneous due to the variability in diagnostic methods. Depressive symptoms similar to those in other dementias are commonly detected in FTD. However, the diagnostic methods are heterogeneous, and symptoms of depression often overlap with manifestations of FTD. Having a standardized diagnostic approach to depression in FTD will greatly facilitate future research in this area.

Often Asked but Rarely Answered: Can Asians Meet DSM-5/ICD-10 Autism Spectrum Disorder Criteria?

PubMed Central

Kim, So Hyun; Koh, Yun-Joo; Lim, Eun-Chung; Kim, Soo-Jeong; Leventhal, Bennett L.

2016-01-01

Abstract Objectives: To evaluate whether Asian (Korean children) populations can be validly diagnosed with autism spectrum disorder (ASD) using Western-based diagnostic instruments and criteria based on Diagnostic and Statistical Manual on Mental Disorders, 5th edition (DSM-5). Methods: Participants included an epidemiologically ascertained 7–14-year-old (N = 292) South Korean cohort from a larger prevalence study (N = 55,266). Main outcomes were based on Western-based diagnostic methods for Korean children using gold standard instruments, Autism Diagnostic Interview-Revised, and Autism Diagnostic Observation Schedule. Factor analysis and ANOVAs were performed to examine factor structure of autism symptoms and identify phenotypic differences between Korean children with ASD and non-ASD diagnoses. Results: Using Western-based diagnostic methods, Korean children with ASD were successfully identified with moderate-to-high diagnostic validity (sensitivities/specificities ranging 64%–93%), strong internal consistency, and convergent/concurrent validity. The patterns of autism phenotypes in a Korean population were similar to those observed in a Western population with two symptom domains (social communication and restricted and repetitive behavior factors). Statistically significant differences in the use of socially acceptable communicative behaviors (e.g., direct gaze, range of facial expressions) emerged between ASD versus non-ASD cases (mostly p < 0.001), ensuring that these can be a similarly valid part of the ASD phenotype in both Asian and Western populations. Conclusions: Despite myths, biases, and stereotypes about Asian social behavior, Asians (at least Korean children) typically use elements of reciprocal social interactions similar to those in the West. Therefore, standardized diagnostic methods widely used for ASD in Western culture can be validly used as part of the assessment process and research with Koreans and, possibly, other Asians. PMID:27315155

Modification of the Microtiter Reading Mirror for Use in the Standardized Micro Complement Fixation Test

PubMed Central

Hui, Gabriel W. K.

1971-01-01

Modification of the Microtiter reading mirror used in the standardized diagnostic complement fixation method permits convenient estimation of the results in per cent hemolysis by direct visual comparison with the hemolytic standards. Images PMID:5564678

A Prospective Study of the Use of Fetal Intelligent Navigation Echocardiography (FINE) to Obtain Standard Fetal Echocardiography Views

PubMed Central

Veronese, Paola; Bogana, Gianna; Cerutti, Alessia; Yeo, Lami; Romero, Roberto; Gervasi, Maria Teresa

2016-01-01

Objective To evaluate the performance of Fetal Intelligent Navigation Echocardiography (FINE) applied to spatiotemporal image correlation (STIC) volume datasets of the normal fetal heart in generating standard fetal echocardiography views. Methods In this prospective cohort study of patients with normal fetal hearts (19-30 gestational weeks), one or more STIC volume datasets were obtained of the apical four-chamber view. Each STIC volume successfully obtained was evaluated by STICLoop™ to determine its appropriateness before applying the FINE method. Visualization rates for standard fetal echocardiography views using diagnostic planes and/or Virtual Intelligent Sonographer Assistance (VIS-Assistance®) were calculated. Results One or more STIC volumes (n=463 total) were obtained in 246 patients. A single STIC volume per patient was analyzed using the FINE method. In normal cases, FINE was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 76-100% of cases; 2) VIS-Assistance® in 96-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 96-100% of cases. Conclusion FINE applied to STIC volumes can successfully generate nine standard fetal echocardiography views in 96-100% of cases in the second and third trimesters. This suggests that the technology can be used as a method to screen for congenital heart disease. PMID:27309391

Systematic Review and Meta-Analysis of Studies Evaluating Diagnostic Test Accuracy: A Practical Review for Clinical Researchers-Part II. Statistical Methods of Meta-Analysis

PubMed Central

Lee, Juneyoung; Kim, Kyung Won; Choi, Sang Hyun; Huh, Jimi

2015-01-01

Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies. PMID:26576107

[The autopsy of the brain and spinal cord in the diagnosis of neurodegenerative diseases - a practical approach to optimize the examination].

PubMed

Rohan, Zdeněk; Matěj, Radoslav

2015-01-01

Brain and spinal cord autopsies aimed at neuropathological diagnosis of the causes of dementia and motor abnormalities are of increasing importance. Neuropathological brain examination is often the only diagnostic modality capable of definitive diagnosis of a neurodegenerative disease and thus serves as invaluable feedback for clinicians and biochemical and imaging diagnostics. The brain and spinal cord autopsy is performed following a standardized protocol and its goal is to sample all diagnostically relevant structures. Subsequent diagnostics are then done using standard and special histologic stainings, however state-of-the-art diagnostics can be achieved only using immunohistochemical methods. The purpose of the article is to provide the pathologists with a brief and practical guideline for brain and spinal cord autopsy when diagnosis of a neurodegenerative disease is suspected.

The Research Diagnostic Criteria for Temporomandibular Disorders. I: overview and methodology for assessment of validity.

PubMed

Schiffman, Eric L; Truelove, Edmond L; Ohrbach, Richard; Anderson, Gary C; John, Mike T; List, Thomas; Look, John O

2010-01-01

The purpose of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Validation Project was to assess the diagnostic validity of this examination protocol. The aim of this article is to provide an overview of the project's methodology, descriptive statistics, and data for the study participant sample. This article also details the development of reliable methods to establish the reference standards for assessing criterion validity of the Axis I RDC/TMD diagnoses. The Axis I reference standards were based on the consensus of two criterion examiners independently performing a comprehensive history, clinical examination, and evaluation of imaging. Intersite reliability was assessed annually for criterion examiners and radiologists. Criterion examination reliability was also assessed within study sites. Study participant demographics were comparable to those of participants in previous studies using the RDC/TMD. Diagnostic agreement of the criterion examiners with each other and with the consensus-based reference standards was excellent with all kappas > or = 0.81, except for osteoarthrosis (moderate agreement, k = 0.53). Intrasite criterion examiner agreement with reference standards was excellent (k > or = 0.95). Intersite reliability of the radiologists for detecting computed tomography-disclosed osteoarthrosis and magnetic resonance imaging-disclosed disc displacement was good to excellent (k = 0.71 and 0.84, respectively). The Validation Project study population was appropriate for assessing the reliability and validity of the RDC/TMD Axis I and II. The reference standards used to assess the validity of Axis I TMD were based on reliable and clinically credible methods.

[Rapid analysis on phenolic compounds in Rheum palmatum based on UPLC-Q-TOF/MSE combined with diagnostic ions filter].

PubMed

Wang, Qing; Lu, Zhi-Wei; Liu, Yue-Hong; Wang, Ming-Ling; Fu, Shuang; Zhang, Qing-Qing; Zhao, Hui-Zhen; Zhang, Zhi-Xin; Xie, Zi-Ye; Huang, Zheng-Hai; Yu, Hong-Hong; Zhou, Wen-Juan; Gao, Xiao-Yan

2017-05-01

Diagnostic ions filter method was used to rapidly detect and identify the phenolic compounds in Rheum palmatum based on ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MSE). The representative authentic standards of phenolic compounds, including gallic acid, (+)-catechin, (－)-epicatechin, (－)-epicatechin-3-O-gallate and procyanidin B2, were subjected to analysis by UPLC-Q-TOF/MSE system with negative ion mode. Fragmentation patterns of each standard were summarized based on assigned fragment ions. The prominent product ions were selected as diagnostic ions. Subsequently, diagnostic ions filter was employed to rapidly recognize analogous skeletons. Combined with retention time, accurate mass, characteristic fragments and previous literature data, the structures of the filtered compounds were identified or tentatively characterized. A total 63 phenolic compounds (36 phenolic acid derivatives, 8 flavonoid derivatives and 19 tennis derivatives) in R. palmatum were identified, including 6 potential new compounds. The method of diagnostic ions filter could rapidly detect and identify phenolic compounds in R. palmatum This study provides a method for rapid detection of phenolic compounds in R. palmatum and is expected to complete the material basis of rhubarb. Copyright© by the Chinese Pharmaceutical Association.

[Current macro-diagnostic trends of forensic medicine in the Czech Republic].

PubMed

Frišhons, Jan; Kučerová, Štěpánka; Jurda, Mikoláš; Sokol, Miloš; Vojtíšek, Tomáš; Hejna, Petr

2017-01-01

Over the last few years, advanced diagnostic methods have penetrated in the realm of forensic medicine in addition to standard autopsy techniques supported by traditional X-ray examination and macro-diagnostic laboratory tests. Despite the progress of imaging methods, the conventional autopsy has remained basic and essential diagnostic tool in forensic medicine. Postmortem computed tomography and magnetic resonance imaging are far the most progressive modern radio diagnostic methods setting the current trend of virtual autopsies all over the world. Up to now, only two institutes of forensic medicine have available postmortem computed tomography for routine diagnostic purposes in the Czech Republic. Postmortem magnetic resonance is currently unattainable for routine diagnostic use and was employed only for experimental purposes. Photogrammetry is digital method focused primarily on body surface imaging. Recently, the most fruitful results have been yielded from the interdisciplinary cooperation between forensic medicine and forensic anthropology with the implementation of body scanning techniques and 3D printing. Non-invasive and mini-invasive investigative methods such as postmortem sonography and postmortem endoscopy was unsystematically tested for diagnostic performance with good outcomes despite of limitations of these methods in postmortem application. Other futuristic methods, such as the use of a drone to inspect the crime scene are still experimental tools. The authors of the article present a basic overview of the both routinely and experimentally used investigative methods and current macro-diagnostic trends of the forensic medicine in the Czech Republic.

Method matters: Understanding diagnostic reliability in DSM-IV and DSM-5.

PubMed

Chmielewski, Michael; Clark, Lee Anna; Bagby, R Michael; Watson, David

2015-08-01

Diagnostic reliability is essential for the science and practice of psychology, in part because reliability is necessary for validity. Recently, the DSM-5 field trials documented lower diagnostic reliability than past field trials and the general research literature, resulting in substantial criticism of the DSM-5 diagnostic criteria. Rather than indicating specific problems with DSM-5, however, the field trials may have revealed long-standing diagnostic issues that have been hidden due to a reliance on audio/video recordings for estimating reliability. We estimated the reliability of DSM-IV diagnoses using both the standard audio-recording method and the test-retest method used in the DSM-5 field trials, in which different clinicians conduct separate interviews. Psychiatric patients (N = 339) were diagnosed using the SCID-I/P; 218 were diagnosed a second time by an independent interviewer. Diagnostic reliability using the audio-recording method (N = 49) was "good" to "excellent" (M κ = .80) and comparable to the DSM-IV field trials estimates. Reliability using the test-retest method (N = 218) was "poor" to "fair" (M κ = .47) and similar to DSM-5 field-trials' estimates. Despite low test-retest diagnostic reliability, self-reported symptoms were highly stable. Moreover, there was no association between change in self-report and change in diagnostic status. These results demonstrate the influence of method on estimates of diagnostic reliability. (c) 2015 APA, all rights reserved).

An objective method and measuring equipment for noise control and acoustic diagnostics of motorcars. [acoustic diagnostics on automobile engines

NASA Technical Reports Server (NTRS)

Kacprowski, J.; Motylewski, J.; Miazga, J.

1974-01-01

An objective method and apparatus for noise control and acoustic diagnostics of motorcar engines are reported. The method and apparatus let us know whether the noisiness of the vehicle under test exceeds the admissible threshold levels given by appropriate standards and if so what is the main source of the excessive noise. The method consists in measuring both the overall noise level and the sound pressure levels in definite frequency bands while the engine speed is controlled as well and may be fixed at prescribed values. Whenever the individually adjusted threshold level has been exceeded in any frequency band, a self-sustaining control signal is sent.

Diagnostic testing for Giardia infections.

PubMed

Heyworth, Martin F

2014-03-01

The traditional method for diagnosing Giardia infections involves microscopic examination of faecal specimens for Giardia cysts. This method is subjective and relies on observer experience. From the 1980s onwards, objective techniques have been developed for diagnosing Giardia infections, and are superseding diagnostic techniques reliant on microscopy. Detection of Giardia antigen(s) by immunoassay is the basis of commercially available diagnostic kits. Various nucleic acid amplification techniques (NAATs) can demonstrate DNA of Giardia intestinalis, and have the potential to become standard approaches for diagnosing Giardia infections. Of such techniques, methods involving either fluorescent microspheres (Luminex) or isothermal amplification of DNA (loop-mediated isothermal amplification; LAMP) are especially promising.

Attitudes and beliefs toward the use of a dental diagnostic terminology A survey of dental providers in a dental practice

PubMed Central

Ramoni, Rachel B.; Walji, Muhammad F.; Kim, Soyun; Tokede, Oluwabunmi; McClellan, Lyle; Simmons, Kristen; Skourtes, Eugene; Yansane, Alfa; White, Joel M.; Kalenderian, Elsbeth

2015-01-01

Background Attitudes and views are critical to the adoption of innovation. While there have been broadening calls for a standardized dental diagnostic terminology, little is known about the views of private practice dental team members towards the adoption of such a terminology. Methods A survey was developed using validated questions identified through literature review. Domain experts’ input allowed for further modifications. The final survey was administered electronically to 814 team members at a multi-office practice based in the Pacific Northwest. Results Response proportion was 92%. The survey had excellent reliability (Cronbach alpha coefficient = 0.87). Results suggested that participants showed, in general, positive attitudes and beliefs towards using a standardized diagnostic terminology in their practices. Additional written comments by participants highlighted the potential for improved communication with use of the terminology. Conclusions Dental providers and staff in one multi-office practice showed positive attitudes towards the use of a diagnostic terminology, specifically they believed it would improve communication between the dentist and patient as well as among providers, while expressing some concerns if using standardized dental diagnostic terms helps clinicians to deliver better dental care. Practical Implications As the dental profession is advancing towards the use of standardized diagnostic terminologies, successful implementation will require that dental team leaders prepare their dental teams by gauging their attitude toward the use of such a terminology. PMID:26025826

Three Diagnostic Approaches to Asperger Syndrome: Implications for Research

ERIC Educational Resources Information Center

Klin, Ami; Pauls, David; Schultz, Robert; Volkmar, Fred

2005-01-01

Objective: To examine the implications for research of the use of three alternative definitions for Asperger syndrome (AS). Differences across the three nosologic systems were examined in terms of diagnostic assignment, IQ profiles, comorbid symptoms, and familial aggregation of social and other psychiatric symptoms. Method: Standard data on…

Standardized Methods to Generate Mock (Spiked) Clinical Specimens by Spiking Blood or Plasma with Cultured Pathogens

PubMed Central

Dong, Ming; Fisher, Carolyn; Añez, Germán; Rios, Maria; Nakhasi, Hira L.; Hobson, J. Peyton; Beanan, Maureen; Hockman, Donna; Grigorenko, Elena; Duncan, Robert

2016-01-01

Aims To demonstrate standardized methods for spiking pathogens into human matrices for evaluation and comparison among diagnostic platforms. Methods and Results This study presents detailed methods for spiking bacteria or protozoan parasites into whole blood and virus into plasma. Proper methods must start with a documented, reproducible pathogen source followed by steps that include standardized culture, preparation of cryopreserved aliquots, quantification of the aliquots by molecular methods, production of sufficient numbers of individual specimens and testing of the platform with multiple mock specimens. Results are presented following the described procedures that showed acceptable reproducibility comparing in-house real-time PCR assays to a commercially available multiplex molecular assay. Conclusions A step by step procedure has been described that can be followed by assay developers who are targeting low prevalence pathogens. Significance and Impact of Study The development of diagnostic platforms for detection of low prevalence pathogens such as biothreat or emerging agents is challenged by the lack of clinical specimens for performance evaluation. This deficit can be overcome using mock clinical specimens made by spiking cultured pathogens into human matrices. To facilitate evaluation and comparison among platforms, standardized methods must be followed in the preparation and application of spiked specimens. PMID:26835651

Diagnostic accuracy of tuberculous lymphadenitis fine needle aspiration biopsy confirmed by PCR as gold standard

NASA Astrophysics Data System (ADS)

DSuryadi; Delyuzar; Soekimin

2018-03-01

Indonesia is the second country with the TB (tuberculosis) burden in the world. Improvement in controlling TB and reducing the complications can accelerate early diagnosis and correct treatment. PCR test is a gold standard. However, it is quite expensive for routine diagnosis. Therefore, an accurate and cheaper diagnostic method such as fine needle aspiration biopsy is needed. The study aimsto determine the accuracy of fine needle aspiration biopsy cytology in the diagnosis of tuberculous lymphadenitis. A cross-sectional analytic study was conducted to the samples from patients suspected with tuberculous lymphadenitis. The fine needle aspiration biopsy (FNAB)test was performed and confirmed by PCR test.There is a comparison to the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of both methods. Sensitivity (92.50%), specificity (96.49%), accuracy (94.85%), positive predictive value (94.87%) and negative predictive value (94.83%) were in FNAB test compared to gold standard. We concluded that fine needle aspiration biopsy is a recommendation for a cheaper and accurate diagnostic test for tuberculous lymphadenitis diagnosis.

Comparison of isolated-check visual evoked potential and standard automated perimetry in early glaucoma and high-risk ocular hypertension

PubMed Central

Chen, Xiang-Wu; Zhao, Ying-Xi

2017-01-01

AIM To compare the diagnostic performance of isolated-check visual evoked potential (icVEP) and standard automated perimetry (SAP), for evaluating the application values of icVEP in the detection of early glaucoma. METHODS Totally 144 subjects (288 eyes) were enrolled in this study. icVEP testing was performed with the Neucodia visual electrophysiological diagnostic system. A 15% positive-contrast (bright) condition pattern was used in this device to differentiate between glaucoma patients and healthy control subjects. Signal-to-noise ratios (SNR) were derived based on a multivariate statistic. The eyes were judged as abnormal if the test yielded an SNR≤1. SAP testing was performed with the Humphrey Field Analyzer II. The visual fields were deemed as abnormality if the glaucoma hemifield test results outside normal limits; or the pattern standard deviation with P<0.05; or the cluster of three or more non-edge points on the pattern deviation plot in a single hemifield with P<0.05, one of which must have a P<0.01. Disc photographs were graded as either glaucomatous optic neuropathy or normal by two experts who were masked to all other patient information. Moorfields regression analysis (MRA) used as a separate diagnostic classification was performed by Heidelberg retina tomograph (HRT). RESULTS When the disc photograph grader was used as diagnostic standard, the sensitivity for SAP and icVEP was 32.3% and 38.5% respectively and specificity was 82.3% and 77.8% respectively. When the MRA Classifier was used as the diagnostic standard, the sensitivity for SAP and icVEP was 48.6% and 51.4% respectively and specificity was 84.1% and 78.0% respectively. When the combined structural assessment was used as the diagnostic standard, the sensitivity for SAP and icVEP was 59.2% and 53.1% respectively and specificity was 84.2% and 84.6% respectivlely. There was no statistical significance between the sensitivity or specificity of SAP and icVEP, regardless of which diagnostic standard was based on. CONCLUSION The diagnostic performance of icVEP is not better than that of SAP in the detection of early glaucoma. PMID:28503434

A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference

PubMed Central

Storey, Helen L.; Huang, Ying; Crudder, Chris; Golden, Allison; de los Santos, Tala; Hawkins, Kenneth

2015-01-01

Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS) can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates. PMID:26566275

Validation of next generation sequencing technologies in comparison to current diagnostic gold standards for BRAF, EGFR and KRAS mutational analysis.

PubMed

McCourt, Clare M; McArt, Darragh G; Mills, Ken; Catherwood, Mark A; Maxwell, Perry; Waugh, David J; Hamilton, Peter; O'Sullivan, Joe M; Salto-Tellez, Manuel

2013-01-01

Next Generation Sequencing (NGS) has the potential of becoming an important tool in clinical diagnosis and therapeutic decision-making in oncology owing to its enhanced sensitivity in DNA mutation detection, fast-turnaround of samples in comparison to current gold standard methods and the potential to sequence a large number of cancer-driving genes at the one time. We aim to test the diagnostic accuracy of current NGS technology in the analysis of mutations that represent current standard-of-care, and its reliability to generate concomitant information on other key genes in human oncogenesis. Thirteen clinical samples (8 lung adenocarcinomas, 3 colon carcinomas and 2 malignant melanomas) already genotyped for EGFR, KRAS and BRAF mutations by current standard-of-care methods (Sanger Sequencing and q-PCR), were analysed for detection of mutations in the same three genes using two NGS platforms and an additional 43 genes with one of these platforms. The results were analysed using closed platform-specific proprietary bioinformatics software as well as open third party applications. Our results indicate that the existing format of the NGS technology performed well in detecting the clinically relevant mutations stated above but may not be reliable for a broader unsupervised analysis of the wider genome in its current design. Our study represents a diagnostically lead validation of the major strengths and weaknesses of this technology before consideration for diagnostic use.

A new method to address verification bias in studies of clinical screening tests: cervical cancer screening assays as an example.

PubMed

Xue, Xiaonan; Kim, Mimi Y; Castle, Philip E; Strickler, Howard D

2014-03-01

Studies to evaluate clinical screening tests often face the problem that the "gold standard" diagnostic approach is costly and/or invasive. It is therefore common to verify only a subset of negative screening tests using the gold standard method. However, undersampling the screen negatives can lead to substantial overestimation of the sensitivity and underestimation of the specificity of the diagnostic test. Our objective was to develop a simple and accurate statistical method to address this "verification bias." We developed a weighted generalized estimating equation approach to estimate, in a single model, the accuracy (eg, sensitivity/specificity) of multiple assays and simultaneously compare results between assays while addressing verification bias. This approach can be implemented using standard statistical software. Simulations were conducted to assess the proposed method. An example is provided using a cervical cancer screening trial that compared the accuracy of human papillomavirus and Pap tests, with histologic data as the gold standard. The proposed approach performed well in estimating and comparing the accuracy of multiple assays in the presence of verification bias. The proposed approach is an easy to apply and accurate method for addressing verification bias in studies of multiple screening methods. Copyright © 2014 Elsevier Inc. All rights reserved.

A computational framework for converting textual clinical diagnostic criteria into the quality data model.

PubMed

Hong, Na; Li, Dingcheng; Yu, Yue; Xiu, Qiongying; Liu, Hongfang; Jiang, Guoqian

2016-10-01

Constructing standard and computable clinical diagnostic criteria is an important but challenging research field in the clinical informatics community. The Quality Data Model (QDM) is emerging as a promising information model for standardizing clinical diagnostic criteria. To develop and evaluate automated methods for converting textual clinical diagnostic criteria in a structured format using QDM. We used a clinical Natural Language Processing (NLP) tool known as cTAKES to detect sentences and annotate events in diagnostic criteria. We developed a rule-based approach for assigning the QDM datatype(s) to an individual criterion, whereas we invoked a machine learning algorithm based on the Conditional Random Fields (CRFs) for annotating attributes belonging to each particular QDM datatype. We manually developed an annotated corpus as the gold standard and used standard measures (precision, recall and f-measure) for the performance evaluation. We harvested 267 individual criteria with the datatypes of Symptom and Laboratory Test from 63 textual diagnostic criteria. We manually annotated attributes and values in 142 individual Laboratory Test criteria. The average performance of our rule-based approach was 0.84 of precision, 0.86 of recall, and 0.85 of f-measure; the performance of CRFs-based classification was 0.95 of precision, 0.88 of recall and 0.91 of f-measure. We also implemented a web-based tool that automatically translates textual Laboratory Test criteria into the QDM XML template format. The results indicated that our approaches leveraging cTAKES and CRFs are effective in facilitating diagnostic criteria annotation and classification. Our NLP-based computational framework is a feasible and useful solution in developing diagnostic criteria representation and computerization. Copyright © 2016 Elsevier Inc. All rights reserved.

77 FR 62479 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-15

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee (Committee) will hold... Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee...

Fetal Intelligent Navigation Echocardiography (FINE): a novel method for rapid, simple, and automatic examination of the fetal heart.

PubMed

Yeo, Lami; Romero, Roberto

2013-09-01

To describe a novel method (Fetal Intelligent Navigation Echocardiography (FINE)) for visualization of standard fetal echocardiography views from volume datasets obtained with spatiotemporal image correlation (STIC) and application of 'intelligent navigation' technology. We developed a method to: 1) demonstrate nine cardiac diagnostic planes; and 2) spontaneously navigate the anatomy surrounding each of the nine cardiac diagnostic planes (Virtual Intelligent Sonographer Assistance (VIS-Assistance®)). The method consists of marking seven anatomical structures of the fetal heart. The following echocardiography views are then automatically generated: 1) four chamber; 2) five chamber; 3) left ventricular outflow tract; 4) short-axis view of great vessels/right ventricular outflow tract; 5) three vessels and trachea; 6) abdomen/stomach; 7) ductal arch; 8) aortic arch; and 9) superior and inferior vena cava. The FINE method was tested in a separate set of 50 STIC volumes of normal hearts (18.6-37.2 weeks of gestation), and visualization rates for fetal echocardiography views using diagnostic planes and/or VIS-Assistance® were calculated. To examine the feasibility of identifying abnormal cardiac anatomy, we tested the method in four cases with proven congenital heart defects (coarctation of aorta, tetralogy of Fallot, transposition of great vessels and pulmonary atresia with intact ventricular septum). In normal cases, the FINE method was able to generate nine fetal echocardiography views using: 1) diagnostic planes in 78-100% of cases; 2) VIS-Assistance® in 98-100% of cases; and 3) a combination of diagnostic planes and/or VIS-Assistance® in 98-100% of cases. In all four abnormal cases, the FINE method demonstrated evidence of abnormal fetal cardiac anatomy. The FINE method can be used to visualize nine standard fetal echocardiography views in normal hearts by applying 'intelligent navigation' technology to STIC volume datasets. This method can simplify examination of the fetal heart and reduce operator dependency. The observation of abnormal echocardiography views in the diagnostic planes and/or VIS-Assistance® should raise the index of suspicion for congenital heart disease. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

78 FR 10582 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-14

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee will hold its fourth...) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet on February...

Sensitivity of the ISO 6579:2002/Amd 1:2007 Standard Method for Detection of Salmonella spp. on Mesenteric Lymph Nodes from Slaughter Pigs

PubMed Central

Mainar-Jaime, R. C.; Andrés, S.; Vico, J. P.; San Román, B.; Garrido, V.

2013-01-01

The ISO 6579:2002/Amd 1:2007 (ISO) standard has been the bacteriological standard method used in the European Union for the detection of Salmonella spp. in pig mesenteric lymph nodes (MLN), but there are no published estimates of the diagnostic sensitivity (Se) of the method in this matrix. Here, the Se of the ISO (SeISO) was estimated on 675 samples selected from two populations with different Salmonella prevalences (14 farms with a ≥20% prevalence and 13 farms with a <20% prevalence) and through the use of latent-class models in concert with Bayesian inference, assuming 100% ISO specificity, and an invA-based PCR as the second diagnostic method. The SeISO was estimated to be close to 87%, while the sensitivity of the PCR reached up to 83.6% and its specificity was 97.4%. Interestingly, the bacteriological reanalysis of 33 potential false-negative (PCR-positive) samples allowed isolation of 19 (57.5%) new Salmonella strains, improving the overall diagnostic accuracy of the bacteriology. Considering the usual limitations of bacteriology regarding Se, these results support the adequacy of the ISO for the detection of Salmonella spp. from MLN and also that of the PCR-based method as an alternative or complementary (screening) test for the diagnosis of pig salmonellosis, particularly considering the cost and time benefits of the molecular procedure. PMID:23100334

Usefulness of 3-dimensional stereotactic surface projection FDG PET images for the diagnosis of dementia

PubMed Central

Kim, Jahae; Cho, Sang-Geon; Song, Minchul; Kang, Sae-Ryung; Kwon, Seong Young; Choi, Kang-Ho; Choi, Seong-Min; Kim, Byeong-Chae; Song, Ho-Chun

2016-01-01

Abstract To compare diagnostic performance and confidence of a standard visual reading and combined 3-dimensional stereotactic surface projection (3D-SSP) results to discriminate between Alzheimer disease (AD)/mild cognitive impairment (MCI), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). [18F]fluorodeoxyglucose (FDG) PET brain images were obtained from 120 patients (64 AD/MCI, 38 DLB, and 18 FTD) who were clinically confirmed over 2 years follow-up. Three nuclear medicine physicians performed the diagnosis and rated diagnostic confidence twice; once by standard visual methods, and once by adding of 3D-SSP. Diagnostic performance and confidence were compared between the 2 methods. 3D-SSP showed higher sensitivity, specificity, accuracy, positive, and negative predictive values to discriminate different types of dementia compared with the visual method alone, except for AD/MCI specificity and FTD sensitivity. Correction of misdiagnosis after adding 3D-SSP images was greatest for AD/MCI (56%), followed by DLB (13%) and FTD (11%). Diagnostic confidence also increased in DLB (visual: 3.2; 3D-SSP: 4.1; P < 0.001), followed by AD/MCI (visual: 3.1; 3D-SSP: 3.8; P = 0.002) and FTD (visual: 3.5; 3D-SSP: 4.2; P = 0.022). Overall, 154/360 (43%) cases had a corrected misdiagnosis or improved diagnostic confidence for the correct diagnosis. The addition of 3D-SSP images to visual analysis helped to discriminate different types of dementia in FDG PET scans, by correcting misdiagnoses and enhancing diagnostic confidence in the correct diagnosis. Improvement of diagnostic accuracy and confidence by 3D-SSP images might help to determine the cause of dementia and appropriate treatment. PMID:27930593

78 FR 32612 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-31

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee will hold its seventh...) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet on June 17...

78 FR 1166 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-08

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee will hold its third...) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet on January 22...

78 FR 23872 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-23

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee will hold its sixth...) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet on May 7...

78 FR 16448 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-15

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee will hold its fifth...) on Medical Diagnostic Equipment Accessibility Standards. DATES: The Committee will meet on March 26...

Nested-PCR and a new ELISA-based NovaLisa test kit for malaria diagnosis in an endemic area of Thailand.

PubMed

Thongdee, Pimwan; Chaijaroenkul, Wanna; Kuesap, Jiraporn; Na-Bangchang, Kesara

2014-08-01

Microscopy is considered as the gold standard for malaria diagnosis although its wide application is limited by the requirement of highly experienced microscopists. PCR and serological tests provide efficient diagnostic performance and have been applied for malaria diagnosis and research. The aim of this study was to investigate the diagnostic performance of nested PCR and a recently developed an ELISA-based new rapid diagnosis test (RDT), NovaLisa test kit, for diagnosis of malaria infection, using microscopic method as the gold standard. The performance of nested-PCR as a malaria diagnostic tool is excellent with respect to its high accuracy, sensitivity, specificity, and ability to discriminate Plasmodium species. The sensitivity and specificity of nested-PCR compared with the microscopic method for detection of Plasmodium falciparum, Plasmodium vivax, and P. falciparum/P. vivax mixed infection were 71.4 vs 100%, 100 vs 98.7%, and 100 vs 95.0%, respectively. The sensitivity and specificity of the ELISA-based NovaLisa test kit compared with the microscopic method for detection of Plasmodium genus were 89.0 vs 91.6%, respectively. NovaLisa test kit provided comparable diagnostic performance. Its relatively low cost, simplicity, and rapidity enables large scale field application.

A fast Monte Carlo EM algorithm for estimation in latent class model analysis with an application to assess diagnostic accuracy for cervical neoplasia in women with AGC

PubMed Central

Kang, Le; Carter, Randy; Darcy, Kathleen; Kauderer, James; Liao, Shu-Yuan

2013-01-01

In this article we use a latent class model (LCM) with prevalence modeled as a function of covariates to assess diagnostic test accuracy in situations where the true disease status is not observed, but observations on three or more conditionally independent diagnostic tests are available. A fast Monte Carlo EM (MCEM) algorithm with binary (disease) diagnostic data is implemented to estimate parameters of interest; namely, sensitivity, specificity, and prevalence of the disease as a function of covariates. To obtain standard errors for confidence interval construction of estimated parameters, the missing information principle is applied to adjust information matrix estimates. We compare the adjusted information matrix based standard error estimates with the bootstrap standard error estimates both obtained using the fast MCEM algorithm through an extensive Monte Carlo study. Simulation demonstrates that the adjusted information matrix approach estimates the standard error similarly with the bootstrap methods under certain scenarios. The bootstrap percentile intervals have satisfactory coverage probabilities. We then apply the LCM analysis to a real data set of 122 subjects from a Gynecologic Oncology Group (GOG) study of significant cervical lesion (S-CL) diagnosis in women with atypical glandular cells of undetermined significance (AGC) to compare the diagnostic accuracy of a histology-based evaluation, a CA-IX biomarker-based test and a human papillomavirus (HPV) DNA test. PMID:24163493

Iridology: A systematic review.

PubMed

Ernst, E

1999-02-01

Iridologists claim to be able to diagnose medical conditions through abnormalities of pigmentation in the iris. This technique is popular in many countries. Therefore it is relevant to ask whether it is valid. To systematically review all interpretable tests of the validity of iridology as a diagnostic tool. DATA SOURCE AND EXTRACTION: Three independent literature searches were performed to identify all blinded tests. Data were extracted in a predefined, standardized fashion. Four case control studies were found. The majority of these investigations suggests that iridology is not a valid diagnostic method. The validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values

PubMed Central

Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard. PMID:29387424

Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel 'V-plot' methodology to display accuracy values.

PubMed

Petraco, Ricardo; Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

2018-01-01

Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test's performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Chol rapid and Chol gold ) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.

Understanding diagnostic variability in breast pathology: lessons learned from an expert consensus review panel

PubMed Central

Allison, Kimberly H; Reisch, Lisa M; Carney, Patricia A; Weaver, Donald L; Schnitt, Stuart J; O’Malley, Frances P; Geller, Berta M; Elmore, Joann G

2015-01-01

Aims To gain a better understanding of the reasons for diagnostic variability, with the aim of reducing the phenomenon. Methods and results In preparation for a study on the interpretation of breast specimens (B-PATH), a panel of three experienced breast pathologists reviewed 336 cases to develop consensus reference diagnoses. After independent assessment, cases coded as diagnostically discordant were discussed at consensus meetings. By the use of qualitative data analysis techniques, transcripts of 16 h of consensus meetings for a subset of 201 cases were analysed. Diagnostic variability could be attributed to three overall root causes: (i) pathologist-related; (ii) diagnostic coding/study methodology-related; and (iii) specimen-related. Most pathologist-related root causes were attributable to professional differences in pathologists’ opinions about whether the diagnostic criteria for a specific diagnosis were met, most frequently in cases of atypia. Diagnostic coding/study methodology-related root causes were primarily miscategorizations of descriptive text diagnoses, which led to the development of a standardized electronic diagnostic form (BPATH-Dx). Specimen-related root causes included artefacts, limited diagnostic material, and poor slide quality. After re-review and discussion, a consensus diagnosis could be assigned in all cases. Conclusions Diagnostic variability is related to multiple factors, but consensus conferences, standardized electronic reporting formats and comments on suboptimal specimen quality can be used to reduce diagnostic variability. PMID:24511905

Standardization of uveitis nomenclature for reporting clinical data. Results of the First International Workshop.

PubMed

Jabs, Douglas A; Nussenblatt, Robert B; Rosenbaum, James T

2005-09-01

To begin a process of standardizing the methods for reporting clinical data in the field of uveitis. Consensus workshop. Members of an international working group were surveyed about diagnostic terminology, inflammation grading schema, and outcome measures, and the results used to develop a series of proposals to better standardize the use of these entities. Small groups employed nominal group techniques to achieve consensus on several of these issues. The group affirmed that an anatomic classification of uveitis should be used as a framework for subsequent work on diagnostic criteria for specific uveitic syndromes, and that the classification of uveitis entities should be on the basis of the location of the inflammation and not on the presence of structural complications. Issues regarding the use of the terms "intermediate uveitis," "pars planitis," "panuveitis," and descriptors of the onset and course of the uveitis were addressed. The following were adopted: standardized grading schema for anterior chamber cells, anterior chamber flare, and for vitreous haze; standardized methods of recording structural complications of uveitis; standardized definitions of outcomes, including "inactive" inflammation, "improvement'; and "worsening" of the inflammation, and "corticosteroid sparing," and standardized guidelines for reporting visual acuity outcomes. A process of standardizing the approach to reporting clinical data in uveitis research has begun, and several terms have been standardized.

[Staged oncological screening with TG test].

PubMed

Bakhlaev, I E; Ageenko, A I; Rolik, I S

2006-01-01

The authors present their analysis of screening methods used for early diagnostics of cancer of various localization and for detection of high-risk individuals. They offer a program of step-by-step screening that makes it possible to cover more population with prophylactic examination and to reduce the need for special examination methods. TG-test is a universal and the most informative blastomatous process indicator at any stage, including the preclinical one. The practical screening results double the revealing rate of oncopathology and allow for three-fold reduction in the diagnostic costs compared with standard methods of cancer diagnostics. The medical efficiency of the oncological screening is high; in one third of the examined patients a tumor is diagnosed at the preclinical stage.

Molecular diagnostic methods for invasive fungal disease: the horizon draws nearer?

PubMed

Halliday, C L; Kidd, S E; Sorrell, T C; Chen, S C-A

2015-04-01

Rapid, accurate diagnostic laboratory tests are needed to improve clinical outcomes of invasive fungal disease (IFD). Traditional direct microscopy, culture and histological techniques constitute the 'gold standard' against which newer tests are judged. Molecular diagnostic methods, whether broad-range or fungal-specific, have great potential to enhance sensitivity and speed of IFD diagnosis, but have varying specificities. The use of PCR-based assays, DNA sequencing, and other molecular methods including those incorporating proteomic approaches such as matrix-assisted laser desorption ionisation-time of flight mass spectroscopy (MALDI-TOF MS) have shown promising results. These are used mainly to complement conventional methods since they require standardisation before widespread implementation can be recommended. None are incorporated into diagnostic criteria for defining IFD. Commercial assays may assist standardisation. This review provides an update of molecular-based diagnostic approaches applicable to biological specimens and fungal cultures in microbiology laboratories. We focus on the most common pathogens, Candida and Aspergillus, and the mucormycetes. The position of molecular-based approaches in the detection of azole and echinocandin antifungal resistance is also discussed.

The WHO 2016 verbal autopsy instrument: An international standard suitable for automated analysis by InterVA, InSilicoVA, and Tariff 2.0

PubMed Central

Chandramohan, Daniel; Clark, Samuel J.; Jakob, Robert; Leitao, Jordana; Rao, Chalapati; Riley, Ian; Setel, Philip W.

2018-01-01

Background Verbal autopsy (VA) is a practical method for determining probable causes of death at the population level in places where systems for medical certification of cause of death are weak. VA methods suitable for use in routine settings, such as civil registration and vital statistics (CRVS) systems, have developed rapidly in the last decade. These developments have been part of a growing global momentum to strengthen CRVS systems in low-income countries. With this momentum have come pressure for continued research and development of VA methods and the need for a single standard VA instrument on which multiple automated diagnostic methods can be developed. Methods and findings In 2016, partners harmonized a WHO VA standard instrument that fully incorporates the indicators necessary to run currently available automated diagnostic algorithms. The WHO 2016 VA instrument, together with validated approaches to analyzing VA data, offers countries solutions to improving information about patterns of cause-specific mortality. This VA instrument offers the opportunity to harmonize the automated diagnostic algorithms in the future. Conclusions Despite all improvements in design and technology, VA is only recommended where medical certification of cause of death is not possible. The method can nevertheless provide sufficient information to guide public health priorities in communities in which physician certification of deaths is largely unavailable. The WHO 2016 VA instrument, together with validated approaches to analyzing VA data, offers countries solutions to improving information about patterns of cause-specific mortality. PMID:29320495

Quality and Reporting of Diagnostic Accuracy Studies in TB, HIV and Malaria: Evaluation Using QUADAS and STARD Standards

PubMed Central

Fontela, Patricia Scolari; Pant Pai, Nitika; Schiller, Ian; Dendukuri, Nandini; Ramsay, Andrew; Pai, Madhukar

2009-01-01

Background Poor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV. Methods We identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004–2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively. Findings Ninety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of withdrawals (6%) and reference test execution (10%), absence of index test review bias (19%) and reference test review bias (24%), and report of uninterpretable results (22%). In terms of quality of reporting, 9 STARD indicators were reported in less than 25% of the studies: methods for calculation and estimates of reproducibility (0%), adverse effects of the diagnostic tests (1%), estimates of diagnostic accuracy between subgroups (10%), distribution of severity of disease/other diagnoses (11%), number of eligible patients who did not participate in the study (14%), blinding of the test readers (16%), and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD. Conclusion Recently published diagnostic accuracy studies on commercial tests for TB, malaria and HIV have moderate to low quality and are poorly reported. The more frequent use of tools such as QUADAS and STARD may be necessary to improve the methodological and reporting quality of future diagnostic accuracy studies in infectious diseases. PMID:19915664

The Human Variome Project (HVP) 2009 Forum "Towards Establishing Standards".

PubMed

Howard, Heather J; Horaitis, Ourania; Cotton, Richard G H; Vihinen, Mauno; Dalgleish, Raymond; Robinson, Peter; Brookes, Anthony J; Axton, Myles; Hoffmann, Robert; Tuffery-Giraud, Sylvie

2010-03-01

The May 2009 Human Variome Project (HVP) Forum "Towards Establishing Standards" was a round table discussion attended by delegates from groups representing international efforts aimed at standardizing several aspects of the HVP: mutation nomenclature, description and annotation, clinical ontology, means to better characterize unclassified variants (UVs), and methods to capture mutations from diagnostic laboratories for broader distribution to the medical genetics research community. Methods for researchers to receive credit for their effort at mutation detection were also discussed. (c) 2010 Wiley-Liss, Inc.

Development and Standardization of the Diagnostic Adaptive Behavior Scale: Application of Item Response Theory to the Assessment of Adaptive Behavior.

PubMed

Tassé, Marc J; Schalock, Robert L; Thissen, David; Balboni, Giulia; Bersani, Henry Hank; Borthwick-Duffy, Sharon A; Spreat, Scott; Widaman, Keith F; Zhang, Dalun; Navas, Patricia

2016-03-01

The Diagnostic Adaptive Behavior Scale (DABS) was developed using item response theory (IRT) methods and was constructed to provide the most precise and valid adaptive behavior information at or near the cutoff point of making a decision regarding a diagnosis of intellectual disability. The DABS initial item pool consisted of 260 items. Using IRT modeling and a nationally representative standardization sample, the item set was reduced to 75 items that provide the most precise adaptive behavior information at the cutoff area determining the presence or not of significant adaptive behavior deficits across conceptual, social, and practical skills. The standardization of the DABS is described and discussed.

A simple sandwich ELISA (WELYSSA) for the detection of lyssavirus nucleocapsid in rabies suspected specimens using mouse monoclonal antibodies.

PubMed

Xu, Gelin; Weber, Patrick; Hu, Qiaoling; Xue, Honggang; Audry, Laurent; Li, Chengping; Wu, Jie; Bourhy, Herve

2007-10-01

Monoclonal antibody (MAb)-based capture enzyme-linked immunosorbent assays (ELISA) were developed for the diagnosis of rabies-suspect specimens. A combination of four mouse monoclonal antibodies directed against the rabies virus nucleocapsid was selected and used for the detection. The test was optimized and standardized so that maximum concordance could be maintained with the standard procedures of rabies diagnosis recommended by the WHO expert committee. Using prototype viruses from the different genotypes of lyssavirus and from various geographic origins and phylogenetic lineages, this paper presents a reliable, rapid and transferable diagnostic method, named WELYSSA that readily permits the detection of lyssaviruses belonging to the 7 genotypes of lyssavirus circulating in Europe, Africa, Asia and Oceania. The threshold of detection of lyssavirus nucleocapsids is low (0.8 ng/ml). With a panel of 1030 specimens received for rabies diagnostic testing, this test was found to be highly specific (0.999) and sensitive (0.970) when compared to other recommended rabies diagnostic methods.

DNA methylation-based classification of central nervous system tumours.

PubMed

Capper, David; Jones, David T W; Sill, Martin; Hovestadt, Volker; Schrimpf, Daniel; Sturm, Dominik; Koelsche, Christian; Sahm, Felix; Chavez, Lukas; Reuss, David E; Kratz, Annekathrin; Wefers, Annika K; Huang, Kristin; Pajtler, Kristian W; Schweizer, Leonille; Stichel, Damian; Olar, Adriana; Engel, Nils W; Lindenberg, Kerstin; Harter, Patrick N; Braczynski, Anne K; Plate, Karl H; Dohmen, Hildegard; Garvalov, Boyan K; Coras, Roland; Hölsken, Annett; Hewer, Ekkehard; Bewerunge-Hudler, Melanie; Schick, Matthias; Fischer, Roger; Beschorner, Rudi; Schittenhelm, Jens; Staszewski, Ori; Wani, Khalida; Varlet, Pascale; Pages, Melanie; Temming, Petra; Lohmann, Dietmar; Selt, Florian; Witt, Hendrik; Milde, Till; Witt, Olaf; Aronica, Eleonora; Giangaspero, Felice; Rushing, Elisabeth; Scheurlen, Wolfram; Geisenberger, Christoph; Rodriguez, Fausto J; Becker, Albert; Preusser, Matthias; Haberler, Christine; Bjerkvig, Rolf; Cryan, Jane; Farrell, Michael; Deckert, Martina; Hench, Jürgen; Frank, Stephan; Serrano, Jonathan; Kannan, Kasthuri; Tsirigos, Aristotelis; Brück, Wolfgang; Hofer, Silvia; Brehmer, Stefanie; Seiz-Rosenhagen, Marcel; Hänggi, Daniel; Hans, Volkmar; Rozsnoki, Stephanie; Hansford, Jordan R; Kohlhof, Patricia; Kristensen, Bjarne W; Lechner, Matt; Lopes, Beatriz; Mawrin, Christian; Ketter, Ralf; Kulozik, Andreas; Khatib, Ziad; Heppner, Frank; Koch, Arend; Jouvet, Anne; Keohane, Catherine; Mühleisen, Helmut; Mueller, Wolf; Pohl, Ute; Prinz, Marco; Benner, Axel; Zapatka, Marc; Gottardo, Nicholas G; Driever, Pablo Hernáiz; Kramm, Christof M; Müller, Hermann L; Rutkowski, Stefan; von Hoff, Katja; Frühwald, Michael C; Gnekow, Astrid; Fleischhack, Gudrun; Tippelt, Stephan; Calaminus, Gabriele; Monoranu, Camelia-Maria; Perry, Arie; Jones, Chris; Jacques, Thomas S; Radlwimmer, Bernhard; Gessi, Marco; Pietsch, Torsten; Schramm, Johannes; Schackert, Gabriele; Westphal, Manfred; Reifenberger, Guido; Wesseling, Pieter; Weller, Michael; Collins, Vincent Peter; Blümcke, Ingmar; Bendszus, Martin; Debus, Jürgen; Huang, Annie; Jabado, Nada; Northcott, Paul A; Paulus, Werner; Gajjar, Amar; Robinson, Giles W; Taylor, Michael D; Jaunmuktane, Zane; Ryzhova, Marina; Platten, Michael; Unterberg, Andreas; Wick, Wolfgang; Karajannis, Matthias A; Mittelbronn, Michel; Acker, Till; Hartmann, Christian; Aldape, Kenneth; Schüller, Ulrich; Buslei, Rolf; Lichter, Peter; Kool, Marcel; Herold-Mende, Christel; Ellison, David W; Hasselblatt, Martin; Snuderl, Matija; Brandner, Sebastian; Korshunov, Andrey; von Deimling, Andreas; Pfister, Stefan M

2018-03-22

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology.

Syndrome diagnosis: human intuition or machine intelligence?

PubMed

Braaten, Oivind; Friestad, Johannes

2008-01-01

The aim of this study was to investigate whether artificial intelligence methods can represent objective methods that are essential in syndrome diagnosis. Most syndromes have no external criterion standard of diagnosis. The predictive value of a clinical sign used in diagnosis is dependent on the prior probability of the syndrome diagnosis. Clinicians often misjudge the probabilities involved. Syndromology needs objective methods to ensure diagnostic consistency, and take prior probabilities into account. We applied two basic artificial intelligence methods to a database of machine-generated patients - a 'vector method' and a set method. As reference methods we ran an ID3 algorithm, a cluster analysis and a naive Bayes' calculation on the same patient series. The overall diagnostic error rate for the the vector algorithm was 0.93%, and for the ID3 0.97%. For the clinical signs found by the set method, the predictive values varied between 0.71 and 1.0. The artificial intelligence methods that we used, proved simple, robust and powerful, and represent objective diagnostic methods.

Smartphone-Based Accurate Analysis of Retinal Vasculature towards Point-of-Care Diagnostics

PubMed Central

Xu, Xiayu; Ding, Wenxiang; Wang, Xuemin; Cao, Ruofan; Zhang, Maiye; Lv, Peilin; Xu, Feng

2016-01-01

Retinal vasculature analysis is important for the early diagnostics of various eye and systemic diseases, making it a potentially useful biomarker, especially for resource-limited regions and countries. Here we developed a smartphone-based retinal image analysis system for point-of-care diagnostics that is able to load a fundus image, segment retinal vessels, analyze individual vessel width, and store or uplink results. The proposed system was not only evaluated on widely used public databases and compared with the state-of-the-art methods, but also validated on clinical images directly acquired with a smartphone. An Android app is also developed to facilitate on-site application of the proposed methods. Both visual assessment and quantitative assessment showed that the proposed methods achieved comparable results to the state-of-the-art methods that require high-standard workstations. The proposed system holds great potential for the early diagnostics of various diseases, such as diabetic retinopathy, for resource-limited regions and countries. PMID:27698369

Seeking a valid gold standard for an innovative, dialect-neutral language test.

PubMed

Pearson, Barbara Zurer; Jackson, Janice E; Wu, Haotian

2014-04-01

PURPOSE In this study, the authors explored alternative gold standards to validate an innovative, dialect-neutral language assessment. METHOD Participants were 78 African American children, ages 5;0 (years;months) to 6;11. Twenty participants had previously been identified as having language impairment. The Diagnostic Evaluation of Language Variation-Norm Referenced (DELV-NR; Seymour, Roeper, & J. de Villiers, 2005) was administered, and concurrent language samples (LSs) were collected. Using LS profiles as the gold standard, sensitivity, specificity, and other measures of diagnostic accuracy were compared for diagnoses made from the DELV-NR and participants' clinical status prior to recruitment. In a second analysis, the authors used results from the first analysis to make evidence-based adjustments in the estimates of DELV-NR diagnostic accuracy. RESULTS Accuracy of the DELV-NR relative to LS profiles was greater than that of prior diagnoses, indicating that the DELV-NR was an improvement over preexisting diagnoses for this group. Specificity met conventional standards, but sensitivity was somewhat low. Reanalysis using the positive and negative predictive power of the preexisting diagnosis in a discrepant-resolution procedure revealed that estimates for sensitivity and specificity for the DELV-NR were .85 and .93, respectively. CONCLUSION The authors found that, even after making allowances for the imperfection of available gold standards, clinical decisions made with the DELV-NR achieved high values on conventional measures of diagnostic accuracy.

Diagnostic Performance of a Novel Coronary CT Angiography Algorithm: Prospective Multicenter Validation of an Intracycle CT Motion Correction Algorithm for Diagnostic Accuracy.

PubMed

Andreini, Daniele; Lin, Fay Y; Rizvi, Asim; Cho, Iksung; Heo, Ran; Pontone, Gianluca; Bartorelli, Antonio L; Mushtaq, Saima; Villines, Todd C; Carrascosa, Patricia; Choi, Byoung Wook; Bloom, Stephen; Wei, Han; Xing, Yan; Gebow, Dan; Gransar, Heidi; Chang, Hyuk-Jae; Leipsic, Jonathon; Min, James K

2018-06-01

Motion artifact can reduce the diagnostic accuracy of coronary CT angiography (CCTA) for coronary artery disease (CAD). The purpose of this study was to compare the diagnostic performance of an algorithm dedicated to correcting coronary motion artifact with the performance of standard reconstruction methods in a prospective international multicenter study. Patients referred for clinically indicated invasive coronary angiography (ICA) for suspected CAD prospectively underwent an investigational CCTA examination free from heart rate-lowering medications before they underwent ICA. Blinded core laboratory interpretations of motion-corrected and standard reconstructions for obstructive CAD (≥ 50% stenosis) were compared with ICA findings. Segments unevaluable owing to artifact were considered obstructive. The primary endpoint was per-subject diagnostic accuracy of the intracycle motion correction algorithm for obstructive CAD found at ICA. Among 230 patients who underwent CCTA with the motion correction algorithm and standard reconstruction, 92 (40.0%) had obstructive CAD on the basis of ICA findings. At a mean heart rate of 68.0 ± 11.7 beats/min, the motion correction algorithm reduced the number of nondiagnostic scans compared with standard reconstruction (20.4% vs 34.8%; p < 0.001). Diagnostic accuracy for obstructive CAD with the motion correction algorithm (62%; 95% CI, 56-68%) was not significantly different from that of standard reconstruction on a per-subject basis (59%; 95% CI, 53-66%; p = 0.28) but was superior on a per-vessel basis: 77% (95% CI, 74-80%) versus 72% (95% CI, 69-75%) (p = 0.02). The motion correction algorithm was superior in subgroups of patients with severely obstructive (≥ 70%) stenosis, heart rate ≥ 70 beats/min, and vessels in the atrioventricular groove. The motion correction algorithm studied reduces artifacts and improves diagnostic performance for obstructive CAD on a per-vessel basis and in selected subgroups on a per-subject basis.

77 FR 53163 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-31

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee (Committee) will hold... previously published Notice of Proposed Rulemaking (NPRM) on Medical Diagnostic Equipment Accessibility...

Syndrome Diagnosis: Human Intuition or Machine Intelligence?

PubMed Central

Braaten, Øivind; Friestad, Johannes

2008-01-01

The aim of this study was to investigate whether artificial intelligence methods can represent objective methods that are essential in syndrome diagnosis. Most syndromes have no external criterion standard of diagnosis. The predictive value of a clinical sign used in diagnosis is dependent on the prior probability of the syndrome diagnosis. Clinicians often misjudge the probabilities involved. Syndromology needs objective methods to ensure diagnostic consistency, and take prior probabilities into account. We applied two basic artificial intelligence methods to a database of machine-generated patients - a ‘vector method’ and a set method. As reference methods we ran an ID3 algorithm, a cluster analysis and a naive Bayes’ calculation on the same patient series. The overall diagnostic error rate for the the vector algorithm was 0.93%, and for the ID3 0.97%. For the clinical signs found by the set method, the predictive values varied between 0.71 and 1.0. The artificial intelligence methods that we used, proved simple, robust and powerful, and represent objective diagnostic methods. PMID:19415142

Affirm VPIII microbial identification test can be used to detect gardnerella vaginalis, Candida albicans and trichomonas vaginalis microbial infections in Korean women.

PubMed

Byun, Seung Won; Park, Yeon Joon; Hur, Soo Young

2016-04-01

The aim of this study was to compare Affirm VPIII Microbial Identification Test results for Korean women to those obtained for Gardnerella vaginalis through Nugent score, Candida albicans based on vaginal culture and Trichomonas vaginalis based on wet smear diagnostic standards. Study participants included 195 women with symptomatic or asymptomatic vulvovaginitis under hospital obstetric or gynecologic care. A definite diagnosis was made based on Nugent score for Gardnerella, vaginal culture for Candida and wet prep for Trichomonas vaginalis. Affirm VPIII Microbial Identification Test results were then compared to diagnostic standard results. Of the 195 participants, 152 were symptomatic, while 43 were asymptomatic. Final diagnosis revealed 68 (37.87%) cases of Gardnerella, 29 (14.87%) cases of Candida, one (0.51%) case of Trichomonas, and 10 (5.10%) cases of mixed infections. The detection rates achieved by each detection method (Affirm assay vs diagnostic standard) for Gardnerella and Candida were not significantly different (33.33% vs 34.8% for Gardnerella, 13.33% vs 14.87% for Candida, respectively). The sensitivity and specificity of the Affirm test for Gardnerella compared to the diagnostic standard were 75.0% and 88.98%, respectively. For Candida, the sensitivity and specificity of the Affirm test compared to the diagnostic standard were 82.76% and 98.80%, respectively. The number of Trichomonas cases was too small (1 case) to be statistically analyzed. The Affirm test is a quick tool that can help physicians diagnose and treat patients with infectious vaginitis at the point of care. © 2016 Japan Society of Obstetrics and Gynecology.

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

PubMed Central

Arvanitis, Marios; Anagnostou, Theodora; Fuchs, Beth Burgwyn; Caliendo, Angela M.

2014-01-01

SUMMARY Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use. PMID:24982319

Advances in the Diagnosis of Human Opisthorchiasis: Development of Opisthorchis viverrini Antigen Detection in Urine

PubMed Central

Duenngai, Kunyarat; Wangboon, Chompunoot; Sithithaworn, Jiraporn; Watwiengkam, Nattaya; Namwat, Nisana; Techasen, Anchalee; Loilome, Watcharin; Yongvanit, Puangrat; Loukas, Alex; Sithithaworn, Paiboon; Bethony, Jeffrey M.

2015-01-01

Background Many strategies to control opisthorchiasis have been employed in Thailand, but not in the other neighbouring countries. Specific control methods include mass drug administration (MDA) and health education to reduce raw fish consumption. These control efforts have greatly shifted the epidemiology of Opisthorchis viverrini (OV) infection over the last decade from presenting as densely concentrated "heavy" infections in single villages to widespread "light" OV infections distributed over wide geographical areas. Currently, the "gold standard" detection method for OV infection is formalin ethyl-acetate concentration technique (FECT), which has limited diagnostic sensitivity and diagnostic specificity for light OV infections, with OV eggs often confused with eggs of minute intestinal flukes (MIFs) in feces. In this study, we developed and evaluated the diagnostic performance of a monoclonal antibody-based enzyme-linked immunosorbent assay for the measurement of OV excretory-secretory (ES) antigens in urine (urine OV-ES assay) for the diagnosis of opisthorchiasis compared to the gold standard detection FECT method. Methodology We tested several methods for pre-treating urine samples prior to testing the diagnostic performance of the urine OV-ES assay. Using trichloroacetic acid (TCA) pre-treated urine, we compared detection and quantification of OV infection using the urine OV-ES assay versus FECT in OV-endemic areas in Northeastern Thailand. Receiver operating characteristic (ROC) curves were used to determine the diagnostic sensitivity and specificity of the urine OV-ES assay using TCA pre-treated urine, and to establish diagnostic positivity thresholds. The Positive Predictive Value as well as the likelihood of obtaining a positive test result (LR+) or a negative test result (LR-) were calculated for the established diagnostic positivity threshold. Diagnostic risks (Odds Ratios) were estimated using logistic regression. Results When urine samples were pre-treated with TCA prior to use in the urine OV-ES assay, the analytical sensitivity was significantly improved. Using TCA pre-treatment of urine, the urine OV-ES assay had a limit of detection (LoD) of 39 ng/ml compared to the LoD of 52 ng/mL reported for coprological antigen detection methods. Similarly, the urine OV-ES assay correlated significantly with intensity of OV infection as measured by FECT. The urine OV-ES assay was also able to detect 28 individuals as positive from the 63 (44.4%) individuals previously determined to be negative using FECT. The likelihood of a positive diagnosis of OV infection by urine OV-ES assay increased significantly with the intensity of OV infection as determined by FECT. With reference to FECT, the sensitivity and specificity of the urine OV-ES assay was 81% and 70%, respectively. Conclusion The detection of OV-infection by the urine OV-ES assay showed much greater diagnostic sensitivity and diagnostic specificity than the current "gold standard" FECT method for the detection and quantification of OV infection. Due to its ease-of-use, and noninvasive sample collection (urine), the urine OV-ES assay offers the potential to revolutionize the diagnosis of liver fluke infection and provide an effective tool for control and elimination of these tumorigenic parasites. PMID:26485024

Antimicrobial Susceptibility Testing, Drug Resistance Mechanisms, and Therapy of Infections with Nontuberculous Mycobacteria

PubMed Central

Nash, Kevin A.; Wallace, Richard J.

2012-01-01

Summary: Within the past 10 years, treatment and diagnostic guidelines for nontuberculous mycobacteria have been recommended by the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA). Moreover, the Clinical and Laboratory Standards Institute (CLSI) has published and recently (in 2011) updated recommendations including suggested antimicrobial and susceptibility breakpoints. The CLSI has also recommended the broth microdilution method as the gold standard for laboratories performing antimicrobial susceptibility testing of nontuberculous mycobacteria. This article reviews the laboratory, diagnostic, and treatment guidelines together with established and probable drug resistance mechanisms of the nontuberculous mycobacteria. PMID:22763637

Quantitative polymerase chain reaction (PCR) for detection of aquatic animal pathogens in a diagnostic laboratory setting

USGS Publications Warehouse

Purcell, Maureen K.; Getchell, Rodman G.; McClure, Carol A.; Weber, S.E.; Garver, Kyle A.

2011-01-01

Real-time, or quantitative, polymerase chain reaction (qPCR) is quickly supplanting other molecular methods for detecting the nucleic acids of human and other animal pathogens owing to the speed and robustness of the technology. As the aquatic animal health community moves toward implementing national diagnostic testing schemes, it will need to evaluate how qPCR technology should be employed. This review outlines the basic principles of qPCR technology, considerations for assay development, standards and controls, assay performance, diagnostic validation, implementation in the diagnostic laboratory, and quality assurance and control measures. These factors are fundamental for ensuring the validity of qPCR assay results obtained in the diagnostic laboratory setting.

Developing a new diagnostic algorithm for human papilloma virus associated oropharyngeal carcinoma: an investigation of HPV DNA assays.

PubMed

Cohen, Natasha; Gupta, Michael; Doerwald-Munoz, Lilian; Jang, Dan; Young, James Edward Massey; Archibald, Stuart; Jackson, Bernard; Lee, Jenny; Chernesky, Max

2017-02-13

Human papilloma virus (HPV) has been implicated in the development of a large proportion of oropharyngeal squamous cell carcinoma (OPSCC). Current techniques used to diagnose HPV etiology require histopathologic analysis. We aim to investigate the diagnostic accuracy of a new application non-histopathologic diagnostic tests to help assist diagnosis of HPV-related oropharyngeal tumors. Patients with OPSCC with nodal metastasis were consecutively recruited from a multidisciplinary cancer clinic. Appropriate samples were collected and analyzed. The various tests examined included COBAS® 4800, Cervista® HR and Genotyping. These tests were compared to p16 staining, which was used as the diagnostic standard. StataIC 14.2 was used to perform analysis, including sensitivity, specificity and receiver operator characteristic [ROC] curves. The COBAS® FNA (area under ROC 0.863) and saliva (area under ROC 0.847) samples performed well in diagnosing HPV positive and negative tumors. Samples tested with Cervista® did not corroborate p16 status reliably. We were able to increase the diagnostic yield of the COBAS® FNA samples by applying the results of the saliva test to negative FNA samples which correctly identified 11 additional p16 positive tumors (area under ROC 0.915). Surrogate testing for HPV using alternate methods is feasible and closely predicts the results of standard diagnostic methods. In the future, these could minimize invasive procedures for diagnosing HPV-related oropharyngeal cancer, but also help to diagnose and treat patients with unknown primaries.

77 FR 14706 - Medical Diagnostic Equipment Accessibility Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards AGENCY: Architectural and... for medical diagnostic equipment and issues raised in the public comments on the NPRM. The Access... accessibility standards for medical diagnostic equipment, in consultation with the Commissioner of the Food and...

Nutrigenomics, beta-cell function and type 2 diabetes.

PubMed

Nino-Fong, R; Collins, Tm; Chan, Cb

2007-03-01

The present investigation was designed to investigate the accuracy and precision of lactate measurement obtained with contemporary biosensors (Chiron Diagnostics, Nova Biomedical) and standard enzymatic photometric procedures (Sigma Diagnostics, Abbott Laboratories, Analyticon). Measurements were performed in vitro before and after the stepwise addition of 1 molar sodium lactate solution to samples of fresh frozen plasma to systematically achieve lactate concentrations of up to 20 mmol/l. Precision of the methods investigated varied between 1% and 7%, accuracy ranged between 2% and -33% with the variability being lowest in the Sigma photometric procedure (6%) and more than 13% in both biosensor methods. Biosensors for lactate measurement provide adequate accuracy in mean with the limitation of highly variable results. A true lactate value of 6 mmol/l was found to be presented between 4.4 and 7.6 mmol/l or even with higher difference. Biosensors and standard enzymatic photometric procedures are only limited comparable because the differences between paired determinations presented to be several mmol. The advantage of biosensors is the complete lack of preanalytical sample preparation which appeared to be the major limitation of standard photometry methods.

Polish Adult Reading Test (PART) - construction of Polish test for estimating the level of premorbid intelligence in schizophrenia.

PubMed

Karakuła-Juchnowicz, Hanna; Stecka, Mariola

2017-08-29

In view of unavailability in Poland of the standardized methods to measure PIQ, the aim of the work was to develop a Polish test to assess the premorbid level of intelligence - PART(Polish AdultReading Test) and to measureits psychometric properties, such as validity, reliability as well as standardization in the group of schizophrenia patients. The principles of PART construction were based on the idea of popular worldwide National Adult Reading Test by Hazel Nelson. The research comprised a group of 122 subjects (65 schizophrenia patients and 57 healthy people), aged 18-60 years, matched for age and gender. PART appears to be a method with high internal consistency and reliability measured by test-retest, inter-rater reliability, and the method with acceptable diagnostic and prognostic validity. The standardized procedures of PART have been investigated and described. Considering the psychometric values of PART and a short time of its performance, the test may be a useful diagnostic instrument in the assessment of premorbid level of intelligence in a group of schizophrenic patients.

Conventional and molecular diagnostic strategies for prosthetic joint infections.

PubMed

Esteban, Jaime; Sorlí, Luisa; Alentorn-Geli, Eduard; Puig, Lluís; Horcajada, Juan P

2014-01-01

An accurate diagnosis of prosthetic joint infection (PJI) is the mainstay for an optimized clinical management. This review analyzes different diagnostic strategies of PJI, with special emphasis on molecular diagnostic tools and their current and future applications. Until now, the culture of periprosthetic tissues has been considered the gold standard for the diagnosis of PJI. However, sonication of the implant increases the sensitivity of those cultures and is being increasingly adopted by many centers. Molecular diagnostic methods compared with intraoperative tissue culture, especially if combined with sonication, have a higher sensitivity, a faster turnaround time and are not influenced by previous antimicrobial therapy. However, they still lack a system for detection of antimicrobial susceptibility, which is crucial for an optimized and less toxic therapy of PJI. More studies are needed to assess the clinical value of these methods and their cost-effectiveness.

Rapid molecular diagnostics for multi-drug resistant tuberculosis in India.

PubMed

Ramachandran, Rajeswari; Muniyandi, M

2018-03-01

Rapid molecular diagnostic methods help in the detection of TB and Rifampicin resistance. These methods detect TB early, are accurate and play a crucial role in reducing the burden of drug resistant tuberculosis. Areas covered: This review analyses rapid molecular diagnostic tools used in the diagnosis of MDR-TB in India, such as the Line Probe Assay and GeneXpert. We have discussed the burden of MDR-TB and the impact of recent diagnostic tools on case detection and treatment outcomes. This review also discusses the costs involved in establishing these new techniques in India. Expert commentary: Molecular methods have considerable advantages for the programmatic management of drug resistant TB. These include speed, standardization of testing, potentially high throughput and reduced laboratory biosafety requirements. There is a desperate need for India to adopt modern, rapid, molecular tools with point-of-care tests being currently evaluated. New molecular diagnostic tests appear to be cost effective and also help in detecting missing cases. There is enough evidence to support the scaling up of these new tools in India.

Noninvasive prostate cancer screening based on serum surface-enhanced Raman spectroscopy and support vector machine

NASA Astrophysics Data System (ADS)

Li, Shaoxin; Zhang, Yanjiao; Xu, Junfa; Li, Linfang; Zeng, Qiuyao; Lin, Lin; Guo, Zhouyi; Liu, Zhiming; Xiong, Honglian; Liu, Songhao

2014-09-01

This study aims to present a noninvasive prostate cancer screening methods using serum surface-enhanced Raman scattering (SERS) and support vector machine (SVM) techniques through peripheral blood sample. SERS measurements are performed using serum samples from 93 prostate cancer patients and 68 healthy volunteers by silver nanoparticles. Three types of kernel functions including linear, polynomial, and Gaussian radial basis function (RBF) are employed to build SVM diagnostic models for classifying measured SERS spectra. For comparably evaluating the performance of SVM classification models, the standard multivariate statistic analysis method of principal component analysis (PCA) is also applied to classify the same datasets. The study results show that for the RBF kernel SVM diagnostic model, the diagnostic accuracy of 98.1% is acquired, which is superior to the results of 91.3% obtained from PCA methods. The receiver operating characteristic curve of diagnostic models further confirm above research results. This study demonstrates that label-free serum SERS analysis technique combined with SVM diagnostic algorithm has great potential for noninvasive prostate cancer screening.

Development and Standardization of the Diagnostic Adaptive Behavior Scale: Application of Item Response Theory to the Assessment of Adaptive Behavior

ERIC Educational Resources Information Center

Tassé, Marc J.; Schalock, Robert L.; Thissen, David; Balboni, Giulia; Bersani, Henry, Jr.; Borthwick-Duffy, Sharon A.; Spreat, Scott; Widaman, Keith F.; Zhang, Dalun; Navas, Patricia

2016-01-01

The Diagnostic Adaptive Behavior Scale (DABS) was developed using item response theory (IRT) methods and was constructed to provide the most precise and valid adaptive behavior information at or near the cutoff point of making a decision regarding a diagnosis of intellectual disability. The DABS initial item pool consisted of 260 items. Using IRT…

Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

DOE PAGES

Chrystal, Colin; Burrell, Keith H.; Grierson, Brian A.; ...

2015-10-20

Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in-situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination diagnostic (CER) at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain informationmore » about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. Lastly, the methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.« less

Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

NASA Astrophysics Data System (ADS)

Chrystal, C.; Burrell, K. H.; Grierson, B. A.; Pace, D. C.

2015-10-01

Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

Seeking a Valid Gold Standard for an Innovative, Dialect-Neutral Language Test

ERIC Educational Resources Information Center

Pearson, Barbara Zurer; Jackson, Janice E.; Wu, Haotian

2014-01-01

Purpose: In this study, the authors explored alternative gold standards to validate an innovative, dialect-neutral language assessment. Method: Participants were 78 African American children, ages 5;0 (years;months) to 6;11. Twenty participants had previously been identified as having language impairment. The Diagnostic Evaluation of Language…

True versus Apparent Malaria Infection Prevalence: The Contribution of a Bayesian Approach

PubMed Central

Claes, Filip; Van Hong, Nguyen; Torres, Kathy; Mao, Sokny; Van den Eede, Peter; Thi Thinh, Ta; Gamboa, Dioni; Sochantha, Tho; Thang, Ngo Duc; Coosemans, Marc; Büscher, Philippe; D'Alessandro, Umberto; Berkvens, Dirk; Erhart, Annette

2011-01-01

Aims To present a new approach for estimating the “true prevalence” of malaria and apply it to datasets from Peru, Vietnam, and Cambodia. Methods Bayesian models were developed for estimating both the malaria prevalence using different diagnostic tests (microscopy, PCR & ELISA), without the need of a gold standard, and the tests' characteristics. Several sources of information, i.e. data, expert opinions and other sources of knowledge can be integrated into the model. This approach resulting in an optimal and harmonized estimate of malaria infection prevalence, with no conflict between the different sources of information, was tested on data from Peru, Vietnam and Cambodia. Results Malaria sero-prevalence was relatively low in all sites, with ELISA showing the highest estimates. The sensitivity of microscopy and ELISA were statistically lower in Vietnam than in the other sites. Similarly, the specificities of microscopy, ELISA and PCR were significantly lower in Vietnam than in the other sites. In Vietnam and Peru, microscopy was closer to the “true” estimate than the other 2 tests while as expected ELISA, with its lower specificity, usually overestimated the prevalence. Conclusions Bayesian methods are useful for analyzing prevalence results when no gold standard diagnostic test is available. Though some results are expected, e.g. PCR more sensitive than microscopy, a standardized and context-independent quantification of the diagnostic tests' characteristics (sensitivity and specificity) and the underlying malaria prevalence may be useful for comparing different sites. Indeed, the use of a single diagnostic technique could strongly bias the prevalence estimation. This limitation can be circumvented by using a Bayesian framework taking into account the imperfect characteristics of the currently available diagnostic tests. As discussed in the paper, this approach may further support global malaria burden estimation initiatives. PMID:21364745

Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

PubMed

van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

2017-11-27

Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory analysis our results show similar diagnostic accuracy comparing anatomical (AUC 0.86(0.83-0.89)) and functional reference standards (AUC 0.88(0.84-0.90)). Only the per territory analysis sensitivity did not show significant heterogeneity. None of the groups showed signs of publication bias. The clinical value of semi-quantitative and quantitative CMR perfusion analysis remains uncertain due to extensive inter-study heterogeneity and large differences in CMR perfusion acquisition protocols, reference standards, and methods of assessment of myocardial perfusion parameters. For wide spread implementation, standardization of CMR perfusion techniques is essential. CRD42016040176 .

75 FR 35439 - Medical Diagnostic Equipment Accessibility Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-22

... ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD Medical Diagnostic Equipment... accessibility standards for medical diagnostic equipment to ensure that such equipment is accessible to, and... respect to medical diagnostic equipment and existing guidance for designing accessible medical diagnostic...

Method of gear fault diagnosis based on EEMD and improved Elman neural network

NASA Astrophysics Data System (ADS)

Zhang, Qi; Zhao, Wei; Xiao, Shungen; Song, Mengmeng

2017-05-01

Aiming at crack and wear and so on of gears Fault information is difficult to diagnose usually due to its weak, a gear fault diagnosis method that is based on EEMD and improved Elman neural network fusion is proposed. A number of IMF components are obtained by decomposing denoised all kinds of fault signals with EEMD, and the pseudo IMF components is eliminated by using the correlation coefficient method to obtain the effective IMF component. The energy characteristic value of each effective component is calculated as the input feature quantity of Elman neural network, and the improved Elman neural network is based on standard network by adding a feedback factor. The fault data of normal gear, broken teeth, cracked gear and attrited gear were collected by field collecting. The results were analyzed by the diagnostic method proposed in this paper. The results show that compared with the standard Elman neural network, Improved Elman neural network has the advantages of high diagnostic efficiency.

A clinical utility study of exome sequencing versus conventional genetic testing in pediatric neurology

PubMed Central

Vissers, Lisenka E.L.M.; van Nimwegen, Kirsten J.M.; Schieving, Jolanda H.; Kamsteeg, Erik-Jan; Kleefstra, Tjitske; Yntema, Helger G.; Pfundt, Rolph; van der Wilt, Gert Jan; Krabbenborg, Lotte; Brunner, Han G.; van der Burg, Simone; Grutters, Janneke; Veltman, Joris A.; Willemsen, Michèl A.A.P.

2017-01-01

Purpose: Implementation of novel genetic diagnostic tests is generally driven by technological advances because they promise shorter turnaround times and/or higher diagnostic yields. Other aspects, including impact on clinical management or cost-effectiveness, are often not assessed in detail prior to implementation. Methods: We studied the clinical utility of whole-exome sequencing (WES) in complex pediatric neurology in terms of diagnostic yield and costs. We analyzed 150 patients (and their parents) presenting with complex neurological disorders of suspected genetic origin. In a parallel study, all patients received both the standard diagnostic workup (e.g., cerebral imaging, muscle biopsies or lumbar punctures, and sequential gene-by-gene–based testing) and WES simultaneously. Results: Our unique study design allowed direct comparison of diagnostic yield of both trajectories and provided insight into the economic implications of implementing WES in this diagnostic trajectory. We showed that WES identified significantly more conclusive diagnoses (29.3%) than the standard care pathway (7.3%) without incurring higher costs. Exploratory analysis of WES as a first-tier diagnostic test indicates that WES may even be cost-saving, depending on the extent of other tests being omitted. Conclusion: Our data support such a use of WES in pediatric neurology for disorders of presumed genetic origin. Genet Med advance online publication 23 March 2017 PMID:28333917

Standardizing Plasmodium falciparum infection prevalence measured via microscopy versus rapid diagnostic test.

PubMed

Mappin, Bonnie; Cameron, Ewan; Dalrymple, Ursula; Weiss, Daniel J; Bisanzio, Donal; Bhatt, Samir; Gething, Peter W

2015-11-17

Large-scale mapping of Plasmodium falciparum infection prevalence relies on opportunistic assemblies of infection prevalence data arising from thousands of P. falciparum parasite rate (PfPR) surveys conducted worldwide. Variance in these data is driven by both signal, the true underlying pattern of infection prevalence, and a range of factors contributing to 'noise', including sampling error, differing age ranges of subjects and differing parasite detection methods. Whilst the former two noise components have been addressed in previous studies, the effect of different diagnostic methods used to determine PfPR in different studies has not. In particular, the majority of PfPR data are based on positivity rates determined by either microscopy or rapid diagnostic test (RDT), yet these approaches are not equivalent; therefore a method is needed for standardizing RDT and microscopy-based prevalence estimates prior to use in mapping. Twenty-five recent Demographic and Health surveys (DHS) datasets from sub-Saharan Africa provide child diagnostic test results derived using both RDT and microscopy for each individual. These prevalence estimates were aggregated across level one administrative zones and a Bayesian probit regression model fit to the microscopy- versus RDT-derived prevalence relationship. An errors-in-variables approach was employed to account for sampling error in both the dependent and independent variables. In addition to the diagnostic outcome, RDT type, fever status and recent anti-malarial treatment were extracted from the datasets in order to analyse their effect on observed malaria prevalence. A strong non-linear relationship between the microscopy and RDT-derived prevalence was found. The results of regressions stratified by the additional diagnostic variables (RDT type, fever status and recent anti-malarial treatment) indicate that there is a distinct and consistent difference in the relationship when the data are stratified by febrile status and RDT brand. The relationships defined in this research can be applied to RDT-derived PfPR data to effectively convert them to an estimate of the parasite prevalence expected using microscopy (or vice versa), thereby standardizing the dataset and improving the signal-to-noise ratio. Additionally, the results provide insight on the importance of RDT brands, febrile status and recent anti-malarial treatment for explaining inconsistencies between observed prevalence derived from different diagnostics.

Physical Conditions of a Lensed Star-Forming Galaxy at Z=1.7

NASA Technical Reports Server (NTRS)

Rigby, Jane; Wuyts, E.; Gladders, M.; Sharon, K.; Becker, G. D.

2010-01-01

We report rest-frame optical Keck/NIRSPEC spectroscopy of the brightest lensed galaxy yet discovered, RCSGA 032727-132609 at z=1.7037. From precise measurements of the nebular lines, we infer a number of physical properties: redshift, extinction, star formation rate, ionization parameter, electron density, electron temperature, oxygen abundance, and N/O, Ne/O, and Ar/O abundance ratios. The limit on [O III] 4363 A tightly constrains the oxygen abundance via the "direct" or Tc method, for the first time in all metallicity galaxy at z approx.2. We compare this result to several standard "bright-line" O abundance diagnostics, thereby testing these empirically calibrated diagnostics in situ. Finally, we explore the positions of lensed and unlensed galaxies in standard diagnostic diagrams, and explore the diversity of ionization conditions and mass-metallicity ratios at z=2.

The Physical Conditions of a Lensed Star-Forming Galaxy at Z=1.7

NASA Technical Reports Server (NTRS)

Rigby, Jane; Wuyts, E.; Gladders, M.; Sharon, K.; Becker, G.

2011-01-01

We report rest-frame optical Keck/NIRSPEC spectroscopy of the brightest lensed galaxy yet discovered, RCSGA 032727-132609 at z=1.7037. From precise measurements of the nebular lines, we infer a number of physical properties: redshift ' extinction, star formation rate ' ionization parameter, electron density, electron temperature, oxygen abundance, and N/O, Ne/O, and Ar/O abundance ratios, The limit on [O III] 4363 A tightly constrains the oxygen abundance via the "direct" or Te method, for the first time in an average-metallicity galaxy at z approx.2. We compare this result to several standard "bright-line" O abundance diagnostics, thereby testing these empirically-calibrated diagnostics in situ. Finally, we explore the positions of lensed and unlensed galaxies in standard diagnostic diagrams, to explore the diversity of ionization conditions and mass-metallicity ratios at z=2.

77 FR 39656 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY... Diagnostic Equipment Accessibility Standards. DATES: The first meeting of the committee will be held at a... Equipment Accessibility Standards. See 77 FR 14706 (March 13, 2012). Section 510 of the Rehabilitation Act...

77 FR 67595 - Medical Diagnostic Equipment Accessibility Standards Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-13

...-0003] RIN 3014-AA40 Medical Diagnostic Equipment Accessibility Standards Advisory Committee AGENCY.... SUMMARY: The Medical Diagnostic Equipment Accessibility Standards Advisory Committee (Committee) will hold... Equipment Accessibility Standards. DATES: The Committee will meet on December 3, 2012, from 10:00 a.m. to 5...

Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies: The PRISMA-DTA Statement.

PubMed

McInnes, Matthew D F; Moher, David; Thombs, Brett D; McGrath, Trevor A; Bossuyt, Patrick M; Clifford, Tammy; Cohen, Jérémie F; Deeks, Jonathan J; Gatsonis, Constantine; Hooft, Lotty; Hunt, Harriet A; Hyde, Christopher J; Korevaar, Daniël A; Leeflang, Mariska M G; Macaskill, Petra; Reitsma, Johannes B; Rodin, Rachel; Rutjes, Anne W S; Salameh, Jean-Paul; Stevens, Adrienne; Takwoingi, Yemisi; Tonelli, Marcello; Weeks, Laura; Whiting, Penny; Willis, Brian H

2018-01-23

Systematic reviews of diagnostic test accuracy synthesize data from primary diagnostic studies that have evaluated the accuracy of 1 or more index tests against a reference standard, provide estimates of test performance, allow comparisons of the accuracy of different tests, and facilitate the identification of sources of variability in test accuracy. To develop the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagnostic test accuracy guideline as a stand-alone extension of the PRISMA statement. Modifications to the PRISMA statement reflect the specific requirements for reporting of systematic reviews and meta-analyses of diagnostic test accuracy studies and the abstracts for these reviews. Established standards from the Enhancing the Quality and Transparency of Health Research (EQUATOR) Network were followed for the development of the guideline. The original PRISMA statement was used as a framework on which to modify and add items. A group of 24 multidisciplinary experts used a systematic review of articles on existing reporting guidelines and methods, a 3-round Delphi process, a consensus meeting, pilot testing, and iterative refinement to develop the PRISMA diagnostic test accuracy guideline. The final version of the PRISMA diagnostic test accuracy guideline checklist was approved by the group. The systematic review (produced 64 items) and the Delphi process (provided feedback on 7 proposed items; 1 item was later split into 2 items) identified 71 potentially relevant items for consideration. The Delphi process reduced these to 60 items that were discussed at the consensus meeting. Following the meeting, pilot testing and iterative feedback were used to generate the 27-item PRISMA diagnostic test accuracy checklist. To reflect specific or optimal contemporary systematic review methods for diagnostic test accuracy, 8 of the 27 original PRISMA items were left unchanged, 17 were modified, 2 were added, and 2 were omitted. The 27-item PRISMA diagnostic test accuracy checklist provides specific guidance for reporting of systematic reviews. The PRISMA diagnostic test accuracy guideline can facilitate the transparent reporting of reviews, and may assist in the evaluation of validity and applicability, enhance replicability of reviews, and make the results from systematic reviews of diagnostic test accuracy studies more useful.

Towards Verification of Operational Procedures Using Auto-Generated Diagnostic Trees

NASA Technical Reports Server (NTRS)

Kurtoglu, Tolga; Lutz, Robyn; Patterson-Hine, Ann

2009-01-01

The design, development, and operation of complex space, lunar and planetary exploration systems require the development of general procedures that describe a detailed set of instructions capturing how mission tasks are performed. For both crewed and uncrewed NASA systems, mission safety and the accomplishment of the scientific mission objectives are highly dependent on the correctness of procedures. In this paper, we describe how to use the auto-generated diagnostic trees from existing diagnostic models to improve the verification of standard operating procedures. Specifically, we introduce a systematic method, namely the Diagnostic Tree for Verification (DTV), developed with the goal of leveraging the information contained within auto-generated diagnostic trees in order to check the correctness of procedures, to streamline the procedures in terms of reducing the number of steps or use of resources in them, and to propose alternative procedural steps adaptive to changing operational conditions. The application of the DTV method to a spacecraft electrical power system shows the feasibility of the approach and its range of capabilities

Aminopenicillin-associated exanthem: lymphocyte transformation testing revisited.

PubMed

Trautmann, A; Seitz, C S; Stoevesandt, J; Kerstan, A

2014-12-01

The lymphocyte transformation test (LTT) has been promoted as in-vitro test for diagnosis of drug hypersensitivity. For determination of statistical LTT sensitivity, series of patients with clinically uniform reactions followed by complete drug hypersensitivity work-up are mandatory. Assessment of LTT specificity requires control patients who tolerated exposure to the drug studied. To prospectively determine the diagnostic value of the LTT in a clinically and diagnostically well-defined series of patients. Patients with exanthematous skin eruptions after ampicillin (AMP) intake were included in this study. After exclusion or confirmation of delayed-onset allergic AMP hypersensitivity by skin and provocation testing, two independent LTTs were performed: one standard LTT and a modified LTT with additional anti-CD3/anti-CD28 monoclonal antibody stimulation. By testing, delayed-onset allergic AMP hypersensitivity was diagnosed in 11 patients and definitely ruled out in 26. The standard LTT reached a diagnostic sensitivity of 54.5% while the modified LTT yielded 72.7%. However, the methodical test modification resulted in a decline of specificity from 92.3% (standard LTT) to 76.9%. In cases of AMP-associated exanthems, the diagnostic value of the LTT compared with routine allergy testing is limited. When evaluating such exanthems, provocation testing remains the gold standard. Delayed reading of intradermal skin tests remains most useful to avoid positive provocation reactions. © 2014 John Wiley & Sons Ltd.

Challenges to Global Implementation of Infrared Thermography Technology: Current Perspective

PubMed Central

Shterenshis, Michael

2017-01-01

Medical infrared thermography (IT) produces an image of the infrared waves emitted by the human body as part of the thermoregulation process that can vary in intensity based on the health of the person. This review analyzes recent developments in the use of infrared thermography as a screening and diagnostic tool in clinical and nonclinical settings, and identifies possible future routes for improvement of the method. Currently, infrared thermography is not considered to be a fully reliable diagnostic method. If standard infrared protocol is established and a normative database is available, infrared thermography may become a reliable method for detecting inflammatory processes. PMID:29138741

Challenges to Global Implementation of Infrared Thermography Technology: Current Perspective.

PubMed

Shterenshis, Michael

2017-01-01

Medical infrared thermography (IT) produces an image of the infrared waves emitted by the human body as part of the thermoregulation process that can vary in intensity based on the health of the person. This review analyzes recent developments in the use of infrared thermography as a screening and diagnostic tool in clinical and nonclinical settings, and identifies possible future routes for improvement of the method. Currently, infrared thermography is not considered to be a fully reliable diagnostic method. If standard infrared protocol is established and a normative database is available, infrared thermography may become a reliable method for detecting inflammatory processes.

Diagnostic packages can be assigned accurately in emergency departments. A multi-centre cohort study.

PubMed

Nørgaard, Birgitte; Mogensen, Christian Backer; Teglbjærg, Lars Stubbe; Brabrand, Mikkel; Lassen, Annmarie Touborg

2016-06-01

In the Region of Southern Denmark, the emergency departments categorise patients based on presenting symptoms and a proposed diagnostic package (n = 40) within each category. The diagnostic packages describe relevant clinical information and standard laboratory and other investigations to be performed. Allocation to the right diagnostic package is assumed to be associated with a higher quality. The aim of this study was to describe to which degree the assigned symptom-based diagnostic packages are related to relevant discharge diagnoses. This was a descriptive cohort study. The analysis was based on data on assigned diagnostic package, patient discharge diagnosis, hospital, gender, age, time of admission and discharge, length of stay, diagnostic package assigned, discharge diagnosis and co-morbidity. An acceptable standard for what would be an appropriate primarily diagnostic package was developed using a modified Delphi method. A total of 16,543 patient contacts were identified. Women constituted 52.2% (n = 8,925) of the patients. The median age was 64 years and the median length of stay was one day. All diagnostic packages were represented. A total of 68% of the included patients had been assigned an acceptable diagnostic package (95% confidence interval: 67.2-68.7). We found an appropriate use of one of 30 diagnostic packages in more than 50% of the cases. We found that 68% of the included patients were assigned an acceptable diagnostic package and that about 80% of all acute pathways were covered by 14 diagnostic packages. The study was funded by Region of Southern Denmark. The study was registered with the Danish Data Protection Agency (No. 2008-58-0035). No further approval was required.

Diagnostic articulation tables

NASA Astrophysics Data System (ADS)

Mikhailov, V. G.

2002-09-01

In recent years, considerable progress has been made in the development of instrumental methods for general speech quality and intelligibility evaluation on the basis of modeling the auditory perception of speech and measuring the signal-to-noise ratio. Despite certain advantages (fast measurement procedures with a low labor consumption), these methods are not universal and, in essence, secondary, because they rely on the calibration based on subjective-statistical measurements. At the same time, some specific problems of speech quality evaluation, such as the diagnostics of the factors responsible for the deviation of the speech quality from standard (e.g., accent features of a speaker or individual voice distortions), can be solved by psycholinguistic methods. This paper considers different kinds of diagnostic articulation tables: tables of minimal pairs of monosyllabic words (DRT) based on the Jacobson differential features, tables consisting of multisyllabic quartets of Russian words (the choice method), and tables of incomplete monosyllables of the _VC/CV_ type (the supplementary note method). Comparative estimates of the tables are presented along with the recommendations concerning their application.

Validation of wet mount microscopy against Trichomonas culture among women of reproductive age group in Western province, Sri Lanka.

PubMed

Banneheke, H; Fernandopulle, R; Gunasekara, U; Barua, A; Fernando, N; Wickremasinghe, R

2015-06-01

Wet mount microscopy is the most commonly used diagnostic method for trichomoniasis in clinical diagnostic services all over the world including Sri Lanka due to its availability, simplicity and is relatively inexpensive. However, Trichomonas culture and PCR are the gold standard tests. Unfortunately, neither the culture nor PCR is available for the diagnosis of trichomoniasis in Sri Lanka. Thus, it is important to validate the wet mount microscopy as it is the only available diagnostic test and has not been validated to date in Sri Lanka. The objective was to evaluate the validity and reliability of wet mount microscopy against gold standard Trichomonas culture among clinic based population of reproductive age group women in Western province, Sri Lanka. Women attending hospital and institutional based clinics were enrolled. They were interviewed and high vaginal swabs were taken for laboratory diagnosis by culture and wet mount microscopy. There were 601 participants in the age group of 15-45 years. Wet mount microscopy showed 68% sensitivity, 100% specificity, 100% positive (PPV) and 98% negative predictive values (NPV) (P=0.001, kappa=0.803) respectively against the gold standard culture. The area under the ROC curve was 0.840. Sensitivity of wet mount microscopy is low. However it has high validity and reliability as a specific diagnostic test for trichomoniasis. If it is to be used among women of reproductive age group in Western province, Sri Lanka, a culture method could be adopted as a second test to confirm the negative wet mount for symptomatic patients.

Quantitative assessment of tumour extraction from dermoscopy images and evaluation of computer-based extraction methods for an automatic melanoma diagnostic system.

PubMed

Iyatomi, Hitoshi; Oka, Hiroshi; Saito, Masataka; Miyake, Ayako; Kimoto, Masayuki; Yamagami, Jun; Kobayashi, Seiichiro; Tanikawa, Akiko; Hagiwara, Masafumi; Ogawa, Koichi; Argenziano, Giuseppe; Soyer, H Peter; Tanaka, Masaru

2006-04-01

The aims of this study were to provide a quantitative assessment of the tumour area extracted by dermatologists and to evaluate computer-based methods from dermoscopy images for refining a computer-based melanoma diagnostic system. Dermoscopic images of 188 Clark naevi, 56 Reed naevi and 75 melanomas were examined. Five dermatologists manually drew the border of each lesion with a tablet computer. The inter-observer variability was evaluated and the standard tumour area (STA) for each dermoscopy image was defined. Manual extractions by 10 non-medical individuals and by two computer-based methods were evaluated with STA-based assessment criteria: precision and recall. Our new computer-based method introduced the region-growing approach in order to yield results close to those obtained by dermatologists. The effectiveness of our extraction method with regard to diagnostic accuracy was evaluated. Two linear classifiers were built using the results of conventional and new computer-based tumour area extraction methods. The final diagnostic accuracy was evaluated by drawing the receiver operating curve (ROC) of each classifier, and the area under each ROC was evaluated. The standard deviations of the tumour area extracted by five dermatologists and 10 non-medical individuals were 8.9% and 10.7%, respectively. After assessment of the extraction results by dermatologists, the STA was defined as the area that was selected by more than two dermatologists. Dermatologists selected the melanoma area with statistically smaller divergence than that of Clark naevus or Reed naevus (P = 0.05). By contrast, non-medical individuals did not show this difference. Our new computer-based extraction algorithm showed superior performance (precision, 94.1%; recall, 95.3%) to the conventional thresholding method (precision, 99.5%; recall, 87.6%). These results indicate that our new algorithm extracted a tumour area close to that obtained by dermatologists and, in particular, the border part of the tumour was adequately extracted. With this refinement, the area under the ROC increased from 0.795 to 0.875 and the diagnostic accuracy showed an increase of approximately 20% in specificity when the sensitivity was 80%. It can be concluded that our computer-based tumour extraction algorithm extracted almost the same area as that obtained by dermatologists and provided improved computer-based diagnostic accuracy.

Reporting standards for studies of diagnostic test accuracy in dementia

PubMed Central

Noel-Storr, Anna H.; McCleery, Jenny M.; Richard, Edo; Ritchie, Craig W.; Flicker, Leon; Cullum, Sarah J.; Davis, Daniel; Quinn, Terence J.; Hyde, Chris; Rutjes, Anne W.S.; Smailagic, Nadja; Marcus, Sue; Black, Sandra; Blennow, Kaj; Brayne, Carol; Fiorivanti, Mario; Johnson, Julene K.; Köpke, Sascha; Schneider, Lon S.; Simmons, Andrew; Mattsson, Niklas; Zetterberg, Henrik; Bossuyt, Patrick M.M.; Wilcock, Gordon

2014-01-01

Objective: To provide guidance on standards for reporting studies of diagnostic test accuracy for dementia disorders. Methods: An international consensus process on reporting standards in dementia and cognitive impairment (STARDdem) was established, focusing on studies presenting data from which sensitivity and specificity were reported or could be derived. A working group led the initiative through 4 rounds of consensus work, using a modified Delphi process and culminating in a face-to-face consensus meeting in October 2012. The aim of this process was to agree on how best to supplement the generic standards of the STARD statement to enhance their utility and encourage their use in dementia research. Results: More than 200 comments were received during the wider consultation rounds. The areas at most risk of inadequate reporting were identified and a set of dementia-specific recommendations to supplement the STARD guidance were developed, including better reporting of patient selection, the reference standard used, avoidance of circularity, and reporting of test-retest reliability. Conclusion: STARDdem is an implementation of the STARD statement in which the original checklist is elaborated and supplemented with guidance pertinent to studies of cognitive disorders. Its adoption is expected to increase transparency, enable more effective evaluation of diagnostic tests in Alzheimer disease and dementia, contribute to greater adherence to methodologic standards, and advance the development of Alzheimer biomarkers. PMID:24944261

Quality and reporting of diagnostic accuracy studies in TB, HIV and malaria: evaluation using QUADAS and STARD standards.

PubMed

Fontela, Patricia Scolari; Pant Pai, Nitika; Schiller, Ian; Dendukuri, Nandini; Ramsay, Andrew; Pai, Madhukar

2009-11-13

Poor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV. We identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004-2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively. Ninety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of withdrawals (6%) and reference test execution (10%), absence of index test review bias (19%) and reference test review bias (24%), and report of uninterpretable results (22%). In terms of quality of reporting, 9 STARD indicators were reported in less than 25% of the studies: methods for calculation and estimates of reproducibility (0%), adverse effects of the diagnostic tests (1%), estimates of diagnostic accuracy between subgroups (10%), distribution of severity of disease/other diagnoses (11%), number of eligible patients who did not participate in the study (14%), blinding of the test readers (16%), and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD. Recently published diagnostic accuracy studies on commercial tests for TB, malaria and HIV have moderate to low quality and are poorly reported. The more frequent use of tools such as QUADAS and STARD may be necessary to improve the methodological and reporting quality of future diagnostic accuracy studies in infectious diseases.

Species-specific diagnostic assays for Bonamia ostreae and B. exitiosa in European flat oyster Ostrea edulis: conventional, real-time and multiplex PCR.

PubMed

Ramilo, Andrea; Navas, J Ignacio; Villalba, Antonio; Abollo, Elvira

2013-05-27

Bonamia ostreae and B. exitiosa have caused mass mortalities of various oyster species around the world and co-occur in some European areas. The World Organisation for Animal Health (OIE) has included infections with both species in the list of notifiable diseases. However, official methods for species-specific diagnosis of either parasite have certain limitations. In this study, new species-specific conventional PCR (cPCR) and real-time PCR techniques were developed to diagnose each parasite species. Moreover, a multiplex PCR method was designed to detect both parasites in a single assay. The analytical sensitivity and specificity of each new method were evaluated. These new procedures were compared with 2 OIE-recommended methods, viz. standard histology and PCR-RFLP. The new procedures showed higher sensitivity than the OIE recommended ones for the diagnosis of both species. The sensitivity of tests with the new primers was higher using oyster gills and gonad tissue, rather than gills alone. The lack of a 'gold standard' prevented accurate estimation of sensitivity and specificity of the new methods. The implementation of statistical tools (maximum likelihood method) for the comparison of the diagnostic tests showed the possibility of false positives with the new procedures, although the absence of a gold standard precluded certainty. Nevertheless, all procedures showed negative results when used for the analysis of oysters from a Bonamia-free area.

Standardization of Laboratory Methods for the PERCH Study

PubMed Central

Karron, Ruth A.; Morpeth, Susan C.; Bhat, Niranjan; Levine, Orin S.; Baggett, Henry C.; Brooks, W. Abdullah; Feikin, Daniel R.; Hammitt, Laura L.; Howie, Stephen R. C.; Knoll, Maria Deloria; Kotloff, Karen L.; Madhi, Shabir A.; Scott, J. Anthony G.; Thea, Donald M.; Adrian, Peter V.; Ahmed, Dilruba; Alam, Muntasir; Anderson, Trevor P.; Antonio, Martin; Baillie, Vicky L.; Dione, Michel; Endtz, Hubert P.; Gitahi, Caroline; Karani, Angela; Kwenda, Geoffrey; Maiga, Abdoul Aziz; McClellan, Jessica; Mitchell, Joanne L.; Morailane, Palesa; Mugo, Daisy; Mwaba, John; Mwansa, James; Mwarumba, Salim; Nyongesa, Sammy; Panchalingam, Sandra; Rahman, Mustafizur; Sawatwong, Pongpun; Tamboura, Boubou; Toure, Aliou; Whistler, Toni; O’Brien, Katherine L.; Murdoch, David R.

2017-01-01

Abstract The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1–59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory. PMID:28575358

Rapid polymerase chain reaction diagnosis of white-nose syndrome in bats

USGS Publications Warehouse

Lorch, J.M.; Gargas, A.; Meteyer, C.U.; Berlowski-Zier, B. M.; Green, D.E.; Shearn-Bochsler, V.; Thomas, N.J.; Blehert, D.S.

2010-01-01

A newly developed polymerase chain reaction (PCR)-based method to rapidly and specifically detect Geomyces destructans on the wings of infected bats from small quantities (1-2 mg) of tissue is described in the current study (methods for culturing and isolating G. destructans from bat skin are also described). The lower limits of detection for PCR were 5 fg of purified fungal DNA or 100 conidia per 2 mg of wing tissue. By using histology as the standard, the PCR had a diagnostic specificity of 100% and a diagnostic sensitivity of 96%, whereas the diagnostic sensitivity of culture techniques was only 54%. The accuracy and fast turnaround time of PCR provides field biologists with valuable information on infection status more rapidly than traditional methods, and the small amount of tissue required for the test would allow diagnosis of white-nose syndrome in live animals.

Resonance Raman of BCC and normal skin

NASA Astrophysics Data System (ADS)

Liu, Cheng-hui; Sriramoju, Vidyasagar; Boydston-White, Susie; Wu, Binlin; Zhang, Chunyuan; Pei, Zhe; Sordillo, Laura; Beckman, Hugh; Alfano, Robert R.

2017-02-01

The Resonance Raman (RR) spectra of basal cell carcinoma (BCC) and normal human skin tissues were analyzed using 532nm laser excitation. RR spectral differences in vibrational fingerprints revealed skin normal and cancerous states tissues. The standard diagnosis criterion for BCC tissues are created by native RR biomarkers and its changes at peak intensity. The diagnostic algorithms for the classification of BCC and normal were generated based on SVM classifier and PCA statistical method. These statistical methods were used to analyze the RR spectral data collected from skin tissues, yielding a diagnostic sensitivity of 98.7% and specificity of 79% compared with pathological reports.

Diagnosis of Food Allergy.

PubMed

Gupta, Malika; Cox, Amanda; Nowak-Węgrzyn, Anna; Wang, Julie

2018-02-01

Food allergy diagnosis remains challenging. Most standard methods are unable to differentiate sensitization from clinical allergy. Recognizing food allergy is of utmost importance to prevent life-threatening reactions. On the other hand, faulty interpretation of tests leads to overdiagnosis and unnecessary food avoidances. Highly predictive models have been established for major food allergens based on skin prick testing and food-specific immunoglobulin E but are lacking for most other foods. Although many newer diagnostic techniques are improving the accuracy of food allergy diagnostics, an oral food challenge remains the only definitive method of confirming a food allergy. Copyright © 2017 Elsevier Inc. All rights reserved.

Agreement between diagnoses reached by clinical examination and available reference standards: a prospective study of 216 patients with lumbopelvic pain

PubMed Central

Laslett, Mark; McDonald, Barry; Tropp, Hans; Aprill, Charles N; Öberg, Birgitta

2005-01-01

Background The tissue origin of low back pain (LBP) or referred lower extremity symptoms (LES) may be identified in about 70% of cases using advanced imaging, discography and facet or sacroiliac joint blocks. These techniques are invasive and availability varies. A clinical examination is non-invasive and widely available but its validity is questioned. Diagnostic studies usually examine single tests in relation to single reference standards, yet in clinical practice, clinicians use multiple tests and select from a range of possible diagnoses. There is a need for studies that evaluate the diagnostic performance of clinical diagnoses against available reference standards. Methods We compared blinded clinical diagnoses with diagnoses based on available reference standards for known causes of LBP or LES such as discography, facet, sacroiliac or hip joint blocks, epidurals injections, advanced imaging studies or any combination of these tests. A prospective, blinded validity design was employed. Physiotherapists examined consecutive patients with chronic lumbopelvic pain and/or referred LES scheduled to receive the reference standard examinations. When diagnoses were in complete agreement regardless of complexity, "exact" agreement was recorded. When the clinical diagnosis was included within the reference standard diagnoses, "clinical agreement" was recorded. The proportional chance criterion (PCC) statistic was used to estimate agreement on multiple diagnostic possibilities because it accounts for the prevalence of individual categories in the sample. The kappa statistic was used to estimate agreement on six pathoanatomic diagnoses. Results In a sample of chronic LBP patients (n = 216) with high levels of disability and distress, 67% received a patho-anatomic diagnosis based on available reference standards, and 10% had more than one tissue origin of pain identified. For 27 diagnostic categories and combinations, chance clinical agreement (PCC) was estimated at 13%. "Exact" agreement between clinical and reference standard diagnoses was 32% and "clinical agreement" 51%. For six pathoanatomic categories (disc, facet joint, sacroiliac joint, hip joint, nerve root and spinal stenosis), PCC was 33% with actual agreement 56%. There was no overlap of 95% confidence intervals on any comparison. Diagnostic agreement on the six most common patho-anatomic categories produced a kappa of 0.31. Conclusion Clinical diagnoses agree with reference standards diagnoses more often than chance. Using available reference standards, most patients can have a tissue source of pain identified. PMID:15943873

Research to Establish the Validity, Reliability, and Clinical Utility of a Comprehensive Language Assessment of Mandarin

ERIC Educational Resources Information Center

Liu, Xueman Lucy; de Villiers, Jill; Ning, Chunyan; Rolfhus, Eric; Hutchings, Teresa; Lee, Wendy; Jiang, Fan; Zhang, Yi Wen

2017-01-01

Purpose: With no existing gold standard for comparison, challenges arise for establishing the validity of a new standardized Mandarin language assessment normed in mainland China. Method: A new assessment, Diagnostic Receptive and Expressive Assessment of Mandarin (DREAM), was normed with a stratified sample of 969 children ages 2;6 (years;months)…

Use of bacteriophage cell wall-binding proteins for rapid diagnostics of Listeria.

PubMed

Schmelcher, Mathias; Loessner, Martin J

2014-01-01

Diagnostic protocols for food-borne bacterial pathogens such as Listeria need to be sensitive, specific, rapid, and inexpensive. Conventional culture methods are hampered by lengthy enrichment and incubation steps. Bacteriophage-derived high-affinity binding molecules (cell wall-binding domains, CBDs) specific for Listeria cells have recently been introduced as tools for detection and differentiation of this pathogen in foods. When coupled with magnetic separation, these proteins offer advantages in sensitivity and speed compared to the standard diagnostic methods. Furthermore, fusion of CBDs to differently colored fluorescent reporter proteins enables differentiation of Listeria strains in mixed cultures. This chapter provides protocols for detection of Listeria in food by CBD-based magnetic separation and subsequent multiplexed identification of strains of different serotypes with reporter-CBD fusion proteins.

[Implication of inverse-probability weighting method in the evaluation of diagnostic test with verification bias].

PubMed

Kang, Leni; Zhang, Shaokai; Zhao, Fanghui; Qiao, Youlin

2014-03-01

To evaluate and adjust the verification bias existed in the screening or diagnostic tests. Inverse-probability weighting method was used to adjust the sensitivity and specificity of the diagnostic tests, with an example of cervical cancer screening used to introduce the Compare Tests package in R software which could be implemented. Sensitivity and specificity calculated from the traditional method and maximum likelihood estimation method were compared to the results from Inverse-probability weighting method in the random-sampled example. The true sensitivity and specificity of the HPV self-sampling test were 83.53% (95%CI:74.23-89.93)and 85.86% (95%CI: 84.23-87.36). In the analysis of data with randomly missing verification by gold standard, the sensitivity and specificity calculated by traditional method were 90.48% (95%CI:80.74-95.56)and 71.96% (95%CI:68.71-75.00), respectively. The adjusted sensitivity and specificity under the use of Inverse-probability weighting method were 82.25% (95% CI:63.11-92.62) and 85.80% (95% CI: 85.09-86.47), respectively, whereas they were 80.13% (95%CI:66.81-93.46)and 85.80% (95%CI: 84.20-87.41) under the maximum likelihood estimation method. The inverse-probability weighting method could effectively adjust the sensitivity and specificity of a diagnostic test when verification bias existed, especially when complex sampling appeared.

Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT).

PubMed

Lee, Adria D; Cassiday, Pamela K; Pawloski, Lucia C; Tatti, Kathleen M; Martin, Monte D; Briere, Elizabeth C; Tondella, M Lucia; Martin, Stacey W

2018-01-01

The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for ≤ 2 weeks were asked to return in 2-4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods-pertussis culture as the "gold standard," composite reference standard analysis (CRS), and latent class analysis (LCA). Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis.

Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests.

PubMed

Kalem, Fatma; Ergün, Ayşe Gül; Durmaz, Süleyman; Doğan, Metin; Ertuğrul, Ömür; Gündem, Seval

2016-09-01

The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis. Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied. Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively. According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients. © 2016 Wiley Periodicals, Inc.

Exploration of Analysis Methods for Diagnostic Imaging Tests: Problems with ROC AUC and Confidence Scores in CT Colonography

PubMed Central

Mallett, Susan; Halligan, Steve; Collins, Gary S.; Altman, Doug G.

2014-01-01

Background Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. Methods In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Results Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. Conclusions The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests. PMID:25353643

Quantitative analysis of image quality for acceptance and commissioning of an MRI simulator with a semiautomatic method.

PubMed

Chen, Xinyuan; Dai, Jianrong

2018-05-01

Magnetic Resonance Imaging (MRI) simulation differs from diagnostic MRI in purpose, technical requirements, and implementation. We propose a semiautomatic method for image acceptance and commissioning for the scanner, the radiofrequency (RF) coils, and pulse sequences for an MRI simulator. The ACR MRI accreditation large phantom was used for image quality analysis with seven parameters. Standard ACR sequences with a split head coil were adopted to examine the scanner's basic performance. The performance of simulation RF coils were measured and compared using the standard sequence with different clinical diagnostic coils. We used simulation sequences with simulation coils to test the quality of image and advanced performance of the scanner. Codes and procedures were developed for semiautomatic image quality analysis. When using standard ACR sequences with a split head coil, image quality passed all ACR recommended criteria. The image intensity uniformity with a simulation RF coil decreased about 34% compared with the eight-channel diagnostic head coil, while the other six image quality parameters were acceptable. Those two image quality parameters could be improved to more than 85% by built-in intensity calibration methods. In the simulation sequences test, the contrast resolution was sensitive to the FOV and matrix settings. The geometric distortion of simulation sequences such as T1-weighted and T2-weighted images was well-controlled in the isocenter and 10 cm off-center within a range of ±1% (2 mm). We developed a semiautomatic image quality analysis method for quantitative evaluation of images and commissioning of an MRI simulator. The baseline performances of simulation RF coils and pulse sequences have been established for routine QA. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Steps to standardization and validation of hippocampal volumetry as a biomarker in clinical trials and diagnostic criteria for Alzheimer’s disease

PubMed Central

Jack, Clifford R; Barkhof, Frederik; Bernstein, Matt A; Cantillon, Marc; Cole, Patricia E; DeCarli, Charles; Dubois, Bruno; Duchesne, Simon; Fox, Nick C; Frisoni, Giovanni B; Hampel, Harald; Hill, Derek LG; Johnson, Keith; Mangin, Jean-François; Scheltens, Philip; Schwarz, Adam J; Sperling, Reisa; Suhy, Joyce; Thompson, Paul M; Weiner, Michael; Foster, Norman L

2012-01-01

Background The promise of Alzheimer’s disease (AD) biomarkers has led to their incorporation in new diagnostic criteria and in therapeutic trials; however, significant barriers exist to widespread use. Chief among these is the lack of internationally accepted standards for quantitative metrics. Hippocampal volumetry is the most widely studied quantitative magnetic resonance imaging (MRI) measure in AD and thus represents the most rational target for an initial effort at standardization. Methods and Results The authors of this position paper propose a path toward this goal. The steps include: 1) Establish and empower an oversight board to manage and assess the effort, 2) Adopt the standardized definition of anatomic hippocampal boundaries on MRI arising from the EADC-ADNI hippocampal harmonization effort as a Reference Standard, 3) Establish a scientifically appropriate, publicly available Reference Standard Dataset based on manual delineation of the hippocampus in an appropriate sample of subjects (ADNI), and 4) Define minimum technical and prognostic performance metrics for validation of new measurement techniques using the Reference Standard Dataset as a benchmark. Conclusions Although manual delineation of the hippocampus is the best available reference standard, practical application of hippocampal volumetry will require automated methods. Our intent is to establish a mechanism for credentialing automated software applications to achieve internationally recognized accuracy and prognostic performance standards that lead to the systematic evaluation and then widespread acceptance and use of hippocampal volumetry. The standardization and assay validation process outlined for hippocampal volumetry is envisioned as a template that could be applied to other imaging biomarkers. PMID:21784356

A systematic review and meta-analysis of the diagnostic accuracy of point-of-care tests for the detection of hyperketonemia in dairy cows.

PubMed

Tatone, Elise H; Gordon, Jessica L; Hubbs, Jessie; LeBlanc, Stephen J; DeVries, Trevor J; Duffield, Todd F

2016-08-01

Several rapid tests for use on farm have been validated for the detection of hyperketonemia (HK) in dairy cattle, however the reported sensitivity and specificity of each method varies and no single study has compared them all. Meta-analysis of diagnostic test accuracy is becoming more common in human medical literature but there are few veterinary examples. The objective of this work was to perform a systematic review and meta-analysis to determine the point-of-care testing method with the highest combined sensitivity and specificity, the optimal threshold for each method, and to identify gaps in the literature. A comprehensive literature search resulted in 5196 references. After removing duplicates and performing relevance screening, 23 studies were included for the qualitative synthesis and 18 for the meta-analysis. The three index tests evaluated in the meta-analysis were: the Precision Xtra(®) handheld device measuring beta-hydroxybutyrate (BHB) concentration in whole blood, and Ketostix(®) and KetoTest(®) semi-quantitative strips measuring the concentration of acetoacetate in urine and BHB in milk, respectively. The diagnostic accuracy of the 3 index tests relative to the reference standard measurement of BHB in serum or whole blood between 1.0-1.4mmol/L was compared using the hierarchical summary receiver operator characteristic (HSROC) method. Subgroup analysis was conducted for each index test to examine the accuracy at different thresholds. The impact of the reference standard threshold, the reference standard method, the prevalence of HK in the population, the primary study source and risk of bias of the primary study was explored using meta-regression. The Precision Xtra(®) device had the highest summary sensitivity in whole blood BHB at 1.2mmol/L, 94.8% (CI95%: 92.6-97.0), and specificity, 97.5% (CI95%: 96.9-98.1). The threshold employed (1.2-1.4mmol/L) did not impact the diagnostic accuracy of the test. The Ketostix(®) and KetoTest(®) strips had the highest summary sensitivity and specificity when the trace and weak positive thresholds were used, respectively. Controlling for the source of publication, HK prevalence and reference standard employed did not impact the estimated sensitivity and specificity of the tests. Including only peer-reviewed studies reduced the number of primary studies evaluating the Precision Xtra(®) by 43% and Ketostix(®) by 33%. Diagnosing HK with blood, urine or milk are valid options, however, the diagnostic inaccuracy of urine and milk should be considered when making economic and treatment decisions. Copyright © 2016 Elsevier B.V. All rights reserved.

Unified Least Squares Methods for the Evaluation of Diagnostic Tests With the Gold Standard

PubMed Central

Tang, Liansheng Larry; Yuan, Ao; Collins, John; Che, Xuan; Chan, Leighton

2017-01-01

The article proposes a unified least squares method to estimate the receiver operating characteristic (ROC) parameters for continuous and ordinal diagnostic tests, such as cancer biomarkers. The method is based on a linear model framework using the empirically estimated sensitivities and specificities as input “data.” It gives consistent estimates for regression and accuracy parameters when the underlying continuous test results are normally distributed after some monotonic transformation. The key difference between the proposed method and the method of Tang and Zhou lies in the response variable. The response variable in the latter is transformed empirical ROC curves at different thresholds. It takes on many values for continuous test results, but few values for ordinal test results. The limited number of values for the response variable makes it impractical for ordinal data. However, the response variable in the proposed method takes on many more distinct values so that the method yields valid estimates for ordinal data. Extensive simulation studies are conducted to investigate and compare the finite sample performance of the proposed method with an existing method, and the method is then used to analyze 2 real cancer diagnostic example as an illustration. PMID:28469385

Method for accurate registration of tissue autofluorescence imaging data with corresponding histology: a means for enhanced tumor margin assessment

NASA Astrophysics Data System (ADS)

Unger, Jakob; Sun, Tianchen; Chen, Yi-Ling; Phipps, Jennifer E.; Bold, Richard J.; Darrow, Morgan A.; Ma, Kwan-Liu; Marcu, Laura

2018-01-01

An important step in establishing the diagnostic potential for emerging optical imaging techniques is accurate registration between imaging data and the corresponding tissue histopathology typically used as gold standard in clinical diagnostics. We present a method to precisely register data acquired with a point-scanning spectroscopic imaging technique from fresh surgical tissue specimen blocks with corresponding histological sections. Using a visible aiming beam to augment point-scanning multispectral time-resolved fluorescence spectroscopy on video images, we evaluate two different markers for the registration with histology: fiducial markers using a 405-nm CW laser and the tissue block's outer shape characteristics. We compare the registration performance with benchmark methods using either the fiducial markers or the outer shape characteristics alone to a hybrid method using both feature types. The hybrid method was found to perform best reaching an average error of 0.78±0.67 mm. This method provides a profound framework to validate diagnostical abilities of optical fiber-based techniques and furthermore enables the application of supervised machine learning techniques to automate tissue characterization.

Predicting acute uncomplicated urinary tract infection in women: a systematic review of the diagnostic accuracy of symptoms and signs

PubMed Central

2010-01-01

Background Acute urinary tract infections (UTI) are one of the most common bacterial infections among women presenting to primary care. However, there is a lack of consensus regarding the optimal reference standard threshold for diagnosing UTI. The objective of this systematic review is to determine the diagnostic accuracy of symptoms and signs in women presenting with suspected UTI, across three different reference standards (102 or 103 or 105 CFU/ml). We also examine the diagnostic value of individual symptoms and signs combined with dipstick test results in terms of clinical decision making. Methods Searches were performed through PubMed (1966 to April 2010), EMBASE (1973 to April 2010), Cochrane library (1973 to April 2010), Google scholar and reference checking. Studies that assessed the diagnostic accuracy of symptoms and signs of an uncomplicated UTI using a urine culture from a clean-catch or catherised urine specimen as the reference standard, with a reference standard of at least ≥ 102 CFU/ml were included. Synthesised data from a high quality systematic review were used regarding dipstick results. Studies were combined using a bivariate random effects model. Results Sixteen studies incorporating 3,711 patients are included. The weighted prior probability of UTI varies across diagnostic threshold, 65.1% at ≥ 102 CFU/ml; 55.4% at ≥ 103 CFU/ml and 44.8% at ≥ 102 CFU/ml ≥ 105 CFU/ml. Six symptoms are identified as useful diagnostic symptoms when a threshold of ≥ 102 CFU/ml is the reference standard. Presence of dysuria (+LR 1.30 95% CI 1.20-1.41), frequency (+LR 1.10 95% CI 1.04-1.16), hematuria (+LR 1.72 95%CI 1.30-2.27), nocturia (+LR 1.30 95% CI 1.08-1.56) and urgency (+LR 1.22 95% CI 1.11-1.34) all increase the probability of UTI. The presence of vaginal discharge (+LR 0.65 95% CI 0.51-0.83) decreases the probability of UTI. Presence of hematuria has the highest diagnostic utility, raising the post-test probability of UTI to 75.8% at ≥ 102 CFU/ml and 67.4% at ≥ 103 CFU/ml. Probability of UTI increases to 93.3% and 90.1% at ≥ 102 CFU/ml and ≥ 103 CFU/ml respectively when presence of hematuria is combined with a positive dipstick result for nitrites. Subgroup analysis shows improved diagnostic accuracy using lower reference standards ≥ 102 CFU/ml and ≥ 103 CFU/ml. Conclusions Individual symptoms and signs have a modest ability to raise the pretest-risk of UTI. Diagnostic accuracy improves considerably when combined with dipstick tests particularly tests for nitrites. PMID:20969801

Feasibility study of structured diagnosis methods for functional dyspepsia in Korean medicine clinics.

PubMed

Park, Jeong Hwan; Kim, Soyoung; Park, Jae-Woo; Ko, Seok-Jae; Lee, Sanghun

2017-12-01

Functional dyspepsia (FD) is the seventh most common disease encountered in Korean medicine (KM) clinics. Despite the large number of FD patients visiting KM clinics, the accumulated medical records have no utility in evidence development, due to being unstructured. This study aimed to construct a standard operating procedure (SOP) with appropriate structured diagnostic methods for FD, and assess the feasibility for use in KM clinics. Two rounds of professional surveys were conducted by 10 Korean internal medicine professors to select the representative diagnostic methods. A feasibility study was conducted to evaluate compliance and time required for using the structured diagnostic methods by three specialists in two hospitals. As per the results of the professional survey, five questionnaires and one basic diagnostic method were selected. An SOP was constructed based on the survey results, and a feasibility study showed that the SOP compliance score (out of 5) was 3.45 among the subjects, and 3.25 among the practitioners. The SOP was acceptable and was not deemed difficult to execute. The total execution time was 136.5 minutes, out of which the gastric emptying test time was 129 minutes. This feasibility study of the SOP with structured diagnostic methods for FD confirmed it was adequate for use in KM clinics. It is expected that these study findings will be helpful to clinicians who wish to conduct observational studies as well as to generate quantitative medical records to facilitate Big Data research.

Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

PubMed

Mallett, Susan; Halligan, Steve; Collins, Gary S; Altman, Doug G

2014-01-01

Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.

Different protocols for cryobiopsy versus forceps biopsy in diagnosis of patients with endobronchial tumors.

PubMed

Jabari, Hamidreza; Sami, Ramin; Fakhri, Mohammad; Kiani, Arda

2012-01-01

Forceps biopsy is the standard procedure to obtain specimens in endobronchial lesions. New studies have proposed flexible cryoprobe as an accepted alternative method for this technique. Although diagnostic use of the cryobiopsy is confirmed in few studies, there is paucity of data with regard to an optimum protocol for this method since one of the main considerations in cryobiopsy is the freezing time. To evaluate diagnostic yield and safety of endobronchial biopsies using the flexible cryoprobe. Moreover, different freezing times were assessed to propose an optimized protocol for this diagnostic modality. For each patient with a confirmed intrabronchial lesion, diagnostic o value of forceps biopsy, cryobiopsy in three seconds, cryobiopsy in five seconds and combined results of cryobiopsy in both timings were recorded. A total of 60 patients (39 males and 21 females; Mean age 56.7 +/- 13.3) were included. Specimens that were obtained by cryobiopsy in five seconds were significantly larger than those of forceps biopsy and cryobiopsy in three seconds (p < 0.001). We showed that the achieved diagnostic yields for all three methods were not statistically different (p > 0.05). Simultaneous usage of samples produced in both cryobiopsies can significantly improve the diagnostic yield (p = 0.02). Statistical analysis showed that there were no significant differences in case of bleeding frequency among the three sampling methods. This study confirmed safety and feasibility of cryobiopsy. Additionally, combination of sampling with two different cold induction timings would significantly increase sensitivity of this emerging technique..

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

Comparison of diagnostic methods in the evaluation of onychomycosis.

PubMed

Haghani, Iman; Shokohi, Tahereh; Hajheidari, Zohreh; Khalilian, Alireza; Aghili, Seyed Reza

2013-04-01

Onychomycosis is a common nail problem, accounting for up to half of all nail diseases. Several nail disorders may mimic the onychomycosis clinically. Therefore, a sensitive, quick, and inexpensive test is essential for screening nail specimens for the administration of the proper drug. The aim of this study was to compare 4 different diagnostic methods in the evaluation of onychomycosis and to determine their sensitivity, specificity, positive predictive value, and negative predictive value. In a cross-sectional study, nail specimens were collected from 101 patients suspected to have onychomycosis during a 14-month period. The nail specimens were examined using potassium hydroxide (KOH) 20 %, KOH-treated nail clipping stained with periodic acid-Schiff (KONCPA), and calcofluor white (CFW) stain, and grew a fungal culture. The culture was chosen as the gold standard for statistical analysis using the McNemar and chi-square tests. Out of 101 patients, 100 (99 %) patients had at least 1 of the 4 diagnostic methods positive for the presence of organisms. The positive rates for the fungal culture, KOH preparation, CFW, and KONCPA were 74.2, 85.1, 91.09, and 99.01 %, respectively. The sensitivity and negative predictive value of KONCPA was 100 %. KONCPA was the most sensitive among the tests and was also superior to other methods in its negative predictive value. KONCPA was easy to perform, rapid, and gave significantly higher rates of detection of onychomycosis compared to the standard methods of KOH preparation and fungal culture. Therefore, KONCPA should be the single method of choice for the evaluation of onychomycosis.

International Standards and Reference Materials for Quantitative Molecular Infectious Disease Testing

PubMed Central

Madej, Roberta M.; Davis, Jack; Holden, Marcia J.; Kwang, Stan; Labourier, Emmanuel; Schneider, George J.

2010-01-01

The utility of quantitative molecular diagnostics for patient management depends on the ability to relate patient results to prior results or to absolute values in clinical practice guidelines. To do this, those results need to be comparable across time and methods, either by producing the same value across methods and test versions or by using reliable and stable conversions. Universally available standards and reference materials specific to quantitative molecular technologies are critical to this process but are few in number. This review describes recent history in the establishment of international standards for nucleic acid test development, organizations involved in current efforts, and future issues and initiatives. PMID:20075208

A utility/cost analysis of breast cancer risk prediction algorithms

NASA Astrophysics Data System (ADS)

Abbey, Craig K.; Wu, Yirong; Burnside, Elizabeth S.; Wunderlich, Adam; Samuelson, Frank W.; Boone, John M.

2016-03-01

Breast cancer risk prediction algorithms are used to identify subpopulations that are at increased risk for developing breast cancer. They can be based on many different sources of data such as demographics, relatives with cancer, gene expression, and various phenotypic features such as breast density. Women who are identified as high risk may undergo a more extensive (and expensive) screening process that includes MRI or ultrasound imaging in addition to the standard full-field digital mammography (FFDM) exam. Given that there are many ways that risk prediction may be accomplished, it is of interest to evaluate them in terms of expected cost, which includes the costs of diagnostic outcomes. In this work we perform an expected-cost analysis of risk prediction algorithms that is based on a published model that includes the costs associated with diagnostic outcomes (true-positive, false-positive, etc.). We assume the existence of a standard screening method and an enhanced screening method with higher scan cost, higher sensitivity, and lower specificity. We then assess expected cost of using a risk prediction algorithm to determine who gets the enhanced screening method under the strong assumption that risk and diagnostic performance are independent. We find that if risk prediction leads to a high enough positive predictive value, it will be cost-effective regardless of the size of the subpopulation. Furthermore, in terms of the hit-rate and false-alarm rate of the of the risk prediction algorithm, iso-cost contours are lines with slope determined by properties of the available diagnostic systems for screening.

Near Infrared Imaging as a Diagnostic Tool for Detecting Enamel Demineralization: An in vivo Study

NASA Astrophysics Data System (ADS)

Lucas, Seth Adam

Background and Objectives: For decades there has been an effort to develop alternative optical methods of imaging dental decay utilizing non-ionizing radiation methods. The purpose of this in-vivo study was to demonstrate whether NIR can be used as a diagnostic tool to evaluate dental caries and to compare the sensitivity and specificity of this method with that of conventional methods, including bitewing x-rays and visual inspection. Materials and Methods: 31 test subjects (n=31) from the UCSF orthodontic clinic undergoing orthodontic treatment with planned premolar extractions were recruited. Calibrated examiners performed caries detection examinations using conventional methods: bitewing radiographs and visual inspection. These findings were compared with the results from NIR examinations: transillumination and reflectance. To confirm the results found in the two different detection methods, a gold standard was used. After teeth were extracted, polarized light microscopy and transverse microradiography were performed. Results: A total of 87 premolars were used in the study. NIR identified the occlusal lesions with a sensitivity of 71% and a specificity of 77%, whereas, the visual examination had a sensitivity of only 40% and a specifity of 39%. For interproximal lesions halfway to DEJ, specificity remained constant, but sensitivity improved to 100% for NIR and 75% for x-rays. Conclusions: The results of this preliminary study demonstrate that NIR is just as effective at detecting enamel interproximal lesions as standard dental x-rays. NIR was more effective at detecting occlusal lesions than visual examination alone. NIR shows promise as an alternative diagnostic tool to the conventional methods of x-rays and visual examination and provides a non-ionizing radiation technique.

Effect of Accreditation on Accuracy of Diagnostic Tests in Medical Laboratories

PubMed Central

Jang, Mi-Ae; Yoon, Young Ahn; Song, Junghan; Kim, Jeong-Ho; Min, Won-Ki; Lee, Ji Sung

2017-01-01

Background Medical laboratories play a central role in health care. Many laboratories are taking a more focused and stringent approach to quality system management. In Korea, laboratory standardization efforts undertaken by the Korean Laboratory Accreditation Program (KLAP) and the Korean External Quality Assessment Scheme (KEQAS) may have facilitated an improvement in laboratory performance, but there are no fundamental studies demonstrating that laboratory standardization is effective. We analyzed the results of the KEQAS to identify significant differences between laboratories with or without KLAP and to determine the impact of laboratory standardization on the accuracy of diagnostic tests. Methods We analyzed KEQAS participant data on clinical chemistry tests such as albumin, ALT, AST, and glucose from 2010 to 2013. As a statistical parameter to assess performance bias between laboratories, we compared 4-yr variance index score (VIS) between the two groups with or without KLAP. Results Compared with the group without KLAP, the group with KLAP exhibited significantly lower geometric means of 4-yr VIS for all clinical chemistry tests (P<0.0001); this difference justified a high level of confidence in standardized services provided by accredited laboratories. Confidence intervals for the mean of each test in the two groups (accredited and non-accredited) did not overlap, suggesting that the means of the groups are significantly different. Conclusions These results confirmed that practice standardization is strongly associated with the accuracy of test results. Our study emphasizes the necessity of establishing a system for standardization of diagnostic testing. PMID:28224767

Detection of scabies: A systematic review of diagnostic methods

PubMed Central

Leung, Victor; Miller, Mark

2011-01-01

BACKGROUND: Accurate diagnosis of scabies infection is important for patient treatment and for public health control of scabies epidemics. OBJECTIVE: To systematically review the accuracy and precision of history, physical examination and tests for diagnosing scabies. METHODS: Using a structured search strategy, Medline and Embase databases were searched for English and French language articles that included a diagnosis of scabies. Studies comparing history, physical examination and/or any diagnostic tests with the reference standard of microscopic visualization of mites, eggs or fecal elements obtained from skin scrapings or biopsies were included for analysis. Data were extracted using standard criteria. RESULTS: History and examination of pruritic dermatoses failed to accurately diagnose scabies infection. Dermatoscopy by a trained practitioner has a positive likelihood ratio of 6.5 (95% CI 4.1 to 10.3) and a negative likelihood ratio of 0.1 (95% CI 0.06 to 0.2) for diagnosing scabies. The accuracy of other diagnostic tests could not be calculated from the data in the literature. CONCLUSIONS: In the face of such diagnostic inaccuracy, clinical judgment is still practical in diagnosing scabies. Two tests are used – the burrow ink test and handheld dermatoscopy. The burrow ink test is a simple, rapid, noninvasive test that can be used to screen a large number of patients. Handheld dermatoscopy is an accurate test, but requires special equipment and trained practitioners. Given the morbidity and costs of scabies infection, and that studies to date lack adequate internal and external validity, research to identify or develop accurate diagnostic tests for scabies infection is needed and justifiable. PMID:23205026

A Review of 20 Years of Research on Overdiagnosis and Underdiagnosis in the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project

PubMed Central

2016-01-01

The Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project represents an integration of research methodology into a community-based outpatient practice affiliated with an academic medical centre. The MIDAS project is the largest clinical epidemiological study using semi-structured interviews to assess a wide range of psychiatric disorders in a general clinical outpatient practice. In an early report from the MIDAS project, we found that across diagnostic categories clinicians using unstandardized, unstructured clinical interviews underrecognized diagnostic comorbidity, compared with the results of semi-structured interviews. Moreover, we found that the patients often wanted treatment for symptoms of disorders that were diagnosed as comorbid, rather than principal, conditions. This highlighted the importance, from the patient’s perspective, of conducting thorough diagnostic interviews to diagnose disorders that are not related to the patient’s chief complaint because patients often desire treatment for these additional diagnoses. While several of the initial papers from the MIDAS project identified problems with the detection of comorbid disorders in clinical practice, regarding the diagnosis of bipolar disorder we observed the emergence of an opposite phenomenon—clinician overdiagnosis. The results from the MIDAS project, along with other studies of diagnosis in routine clinical practice, have brought to the forefront the problem with diagnosis in routine clinical practice. An important question is what do these findings suggest about the community standard of care in making psychiatric diagnoses, and whether and how the standard of care should be changed? The implications are discussed. PMID:27253697

A Review of 20 Years of Research on Overdiagnosis and Underdiagnosis in the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) Project.

PubMed

Zimmerman, Mark

2016-02-01

The Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project represents an integration of research methodology into a community-based outpatient practice affiliated with an academic medical centre. The MIDAS project is the largest clinical epidemiological study using semi-structured interviews to assess a wide range of psychiatric disorders in a general clinical outpatient practice. In an early report from the MIDAS project, we found that across diagnostic categories clinicians using unstandardized, unstructured clinical interviews underrecognized diagnostic comorbidity, compared with the results of semi-structured interviews. Moreover, we found that the patients often wanted treatment for symptoms of disorders that were diagnosed as comorbid, rather than principal, conditions. This highlighted the importance, from the patient's perspective, of conducting thorough diagnostic interviews to diagnose disorders that are not related to the patient's chief complaint because patients often desire treatment for these additional diagnoses. While several of the initial papers from the MIDAS project identified problems with the detection of comorbid disorders in clinical practice, regarding the diagnosis of bipolar disorder we observed the emergence of an opposite phenomenon-clinician overdiagnosis. The results from the MIDAS project, along with other studies of diagnosis in routine clinical practice, have brought to the forefront the problem with diagnosis in routine clinical practice. An important question is what do these findings suggest about the community standard of care in making psychiatric diagnoses, and whether and how the standard of care should be changed? The implications are discussed. © The Author(s) 2016.

[Diagnostic imaging of breast cancer : An update].

PubMed

Funke, M

2016-10-01

Advances in imaging of the female breast have substantially influenced the diagnosis and probably also the therapy and prognosis of breast cancer in the past few years. This article gives an overview of the most important imaging modalities in the diagnosis of breast cancer. Digital mammography is considered to be the gold standard for the early detection of breast cancer. Digital breast tomosynthesis can increase the diagnostic accuracy of mammography and is used for the assessment of equivocal or suspicious mammography findings. Other modalities, such as ultrasound and contrast-enhanced magnetic resonance imaging (MRI) play an important role in the diagnostics, staging and follow-up of breast cancer. Percutaneous needle biopsy is a rapid and minimally invasive method for the histological verification of breast cancer. New breast imaging modalities, such as contrast-enhanced spectral mammography, diffusion-weighted MRI and MR spectroscopy can possibly further improve breast cancer diagnostics; however, further studies are necessary to prove the advantages of these methods so that they cannot yet be recommended for routine clinical use.

Clinical and diagnostic utility of saliva as a non-invasive diagnostic fluid:
a systematic review

PubMed Central

Nunes, Lazaro Alessandro Soares; Mussavira, Sayeeda

2015-01-01

This systematic review presents the latest trends in salivary research and its applications in health and disease. Among the large number of analytes present in saliva, many are affected by diverse physiological and pathological conditions. Further, the non-invasive, easy and cost-effective collection methods prompt an interest in evaluating its diagnostic or prognostic utility. Accumulating data over the past two decades indicates towards the possible utility of saliva to monitor overall health, diagnose and treat various oral or systemic disorders and drug monitoring. Advances in saliva based systems biology has also contributed towards identification of several biomarkers, development of diverse salivary diagnostic kits and other sensitive analytical techniques. However, its utilization should be carefully evaluated in relation to standardization of pre-analytical and analytical variables, such as collection and storage methods, analyte circadian variation, sample recovery, prevention of sample contamination and analytical procedures. In spite of all these challenges, there is an escalating evolution of knowledge with the use of this biological matrix. PMID:26110030

Cancer diagnostics: The journey from histomorphology to molecular profiling.

PubMed

Ahmed, Atif A; Abedalthagafi, Malak

2016-09-06

Although histomorphology has made significant advances into the understanding of cancer etiology, classification and pathogenesis, it is sometimes complicated by morphologic ambiguities, and other shortcomings that necessitate the development of ancillary tests to complement its diagnostic value. A new approach to cancer patient management consists of targeting specific molecules or gene mutations in the cancer genome by inhibitory therapy. Molecular diagnostic tests and genomic profiling methods are increasingly being developed to identify tumor targeted molecular profile that is the basis of targeted therapy. Novel targeted therapy has revolutionized the treatment of gastrointestinal stromal tumor, renal cell carcinoma and other cancers that were previously difficult to treat with standard chemotherapy. In this review, we discuss the role of histomorphology in cancer diagnosis and management and the rising role of molecular profiling in targeted therapy. Molecular profiling in certain diagnostic and therapeutic difficulties may provide a practical and useful complement to histomorphology and opens new avenues for targeted therapy and alternative methods of cancer patient management.

Single and combination diagnostic test efficiency and cost analysis for detection and isolation of avian influenza virus from wild bird cloacal swabs

USDA-ARS?s Scientific Manuscript database

Effective laboratory methods for identifying avian influenza virus (AIV) in wild bird populations are crucial to understanding the ecology of this pathogen. The gold standard method has been AIV isolation in chorioallantoic sac (CAS) of specific-pathogen-free (SPF) embryonating chicken eggs (ECE), ...

Decision making in trauma settings: simulation to improve diagnostic skills.

PubMed

Murray, David J; Freeman, Brad D; Boulet, John R; Woodhouse, Julie; Fehr, James J; Klingensmith, Mary E

2015-06-01

In the setting of acute injury, a wrong, missed, or delayed diagnosis can impact survival. Clinicians rely on pattern recognition and heuristics to rapidly assess injuries, but an overreliance on these approaches can result in a diagnostic error. Simulation has been advocated as a method for practitioners to learn how to recognize the limitations of heuristics and develop better diagnostic skills. The objective of this study was to determine whether simulation could be used to provide teams the experiences in managing scenarios that require the use of heuristic as well as analytic diagnostic skills to effectively recognize and treat potentially life-threatening injuries. Ten scenarios were developed to assess the ability of trauma teams to provide initial care to a severely injured patient. Seven standard scenarios simulated severe injuries that once diagnosed could be effectively treated using standard Advanced Trauma Life Support algorithms. Because diagnostic error occurs more commonly in complex clinical settings, 3 complex scenarios required teams to use more advanced diagnostic skills to uncover a coexisting condition and treat the patient. Teams composed of 3 to 5 practitioners were evaluated in the performance of 7 (of 10) randomly selected scenarios (5 standard, 2 complex). Expert rates scored teams using standardized checklists and global scores. Eighty-three surgery, emergency medicine, and anesthesia residents constituted 21 teams. Expert raters were able to reliably score the scenarios. Teams accomplished fewer checklist actions and received lower global scores on the 3 analytic scenarios (73.8% [12.3%] and 5.9 [1.6], respectively) compared with the 7 heuristic scenarios (83.2% [11.7%] and 6.6 [1.3], respectively; P < 0.05 for both). Teams led by more junior residents received higher global scores on the analytic scenarios (6.4 [1.3]) than the more senior team leaders (5.3 [1.7]). This preliminary study indicates that teams led by more senior residents received higher scores when managing heuristic scenarios but were less effective when managing the scenarios that require a more analytic approach. Simulation can be used to provide teams with decision-making experiences in trauma settings and could be used to improve diagnostic skills as well as study the decision-making process.

Biomarker detection of global infectious diseases based on magnetic particles.

PubMed

Carinelli, Soledad; Martí, Mercè; Alegret, Salvador; Pividori, María Isabel

2015-09-25

Infectious diseases affect the daily lives of millions of people all around the world, and are responsible for hundreds of thousands of deaths, mostly in the developing world. Although most of these major infectious diseases are treatable, the early identification of individuals requiring treatment remains a major issue. The incidence of these diseases would be reduced if rapid diagnostic tests were widely available at the community and primary care level in low-resource settings. Strong research efforts are thus being focused on replacing standard clinical diagnostic methods, such as the invasive detection techniques (biopsy or endoscopy) or expensive diagnostic and monitoring methods, by affordable and sensitive tests based on novel biomarkers. The development of new methods that are needed includes solid-phase separation techniques. In this context, the integration of magnetic particles within bioassays and biosensing devices is very promising since they greatly improve the performance of a biological reaction. The diagnosis of clinical samples with magnetic particles can be easily achieved without pre-enrichment, purification or pretreatment steps often required for standard methods, simplifying the analytical procedures. The biomarkers can be specifically isolated and preconcentrated from complex biological matrixes by magnetic actuation, increasing specificity and the sensitivity of the assay. This review addresses these promising features of the magnetic particles for the detection of biomarkers in emerging technologies related with infectious diseases affecting global health, such as malaria, influenza, dengue, tuberculosis or HIV. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of the Sanofi Diagnostics Pasteur Chlamydia Microplate EIA shortened assay with the original standard assay and cell culture.

PubMed

Chan, E L; Brandt, K; Stoneham, H; Horsman, G

1997-08-01

The new Sanofi Diagnostics Pasteur Chlamydia Microplate EIA shortened assay was evaluated by comparison with the original standard assay and cell culture. A total of 853 paired male and female genital tract specimens was tested with both Sanofi Chlamydia Microplate EIA shortened and standard assays and the results were compared with those of cell culture. For confirmation, a blocking assay run in the shortened format was used. Discrepancies between the three methods were resolved by a direct fluorescent antibody (DFA) test on the EIA samples or the culture retentate, or both. After resolution of discrepant results, the standard assay had a sensitivity, specificity, positive predictive value and negative predictive value of 98.5%, 100%, 100% and 99.9%, respectively. The shortened assay results were 100%, 100%, 100% and 100%, respectively. The shortened assay takes approximately 1.5 h less time than the standard assay and this study demonstrated that they have equivalent sensitivity and specificity. The improvement in turnaround time enables results to be reported on the same day.

Intelligent navigation to improve obstetrical sonography.

PubMed

Yeo, Lami; Romero, Roberto

2016-04-01

'Manual navigation' by the operator is the standard method used to obtain information from two-dimensional and volumetric sonography. Two-dimensional sonography is highly operator dependent and requires extensive training and expertise to assess fetal anatomy properly. Most of the sonographic examination time is devoted to acquisition of images, while 'retrieval' and display of diagnostic planes occurs rapidly (essentially instantaneously). In contrast, volumetric sonography has a rapid acquisition phase, but the retrieval and display of relevant diagnostic planes is often time-consuming, tedious and challenging. We propose the term 'intelligent navigation' to refer to a new method of interrogation of a volume dataset whereby identification and selection of key anatomical landmarks allow the system to: 1) generate a geometrical reconstruction of the organ of interest; and 2) automatically navigate, find, extract and display specific diagnostic planes. This is accomplished using operator-independent algorithms that are both predictable and adaptive. Virtual Intelligent Sonographer Assistance (VIS-Assistance®) is a tool that allows operator-independent sonographic navigation and exploration of the surrounding structures in previously identified diagnostic planes. The advantage of intelligent (over manual) navigation in volumetric sonography is the short time required for both acquisition and retrieval and display of diagnostic planes. Intelligent navigation technology automatically realigns the volume, and reorients and standardizes the anatomical position, so that the fetus and the diagnostic planes are consistently displayed in the same manner each time, regardless of the fetal position or the initial orientation. Automatic labeling of anatomical structures, subject orientation and each of the diagnostic planes is also possible. Intelligent navigation technology can operate on conventional computers, and is not dependent on specific ultrasound platforms or on the use of software to perform manual navigation of volume datasets. Diagnostic planes and VIS-Assistance videoclips can be transmitted by telemedicine so that expert consultants can evaluate the images to provide an opinion. The end result is a user-friendly, simple, fast and consistent method of obtaining sonographic images with decreased operator dependency. Intelligent navigation is one approach to improve obstetrical sonography. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

A Standard Mammography Unit - Standard 3D Ultrasound Probe Fusion Prototype: First Results.

PubMed

Schulz-Wendtland, Rüdiger; Jud, Sebastian M; Fasching, Peter A; Hartmann, Arndt; Radicke, Marcus; Rauh, Claudia; Uder, Michael; Wunderle, Marius; Gass, Paul; Langemann, Hanna; Beckmann, Matthias W; Emons, Julius

2017-06-01

The combination of different imaging modalities through the use of fusion devices promises significant diagnostic improvement for breast pathology. The aim of this study was to evaluate image quality and clinical feasibility of a prototype fusion device (fusion prototype) constructed from a standard tomosynthesis mammography unit and a standard 3D ultrasound probe using a new method of breast compression. Imaging was performed on 5 mastectomy specimens from patients with confirmed DCIS or invasive carcinoma (BI-RADS ™ 6). For the preclinical fusion prototype an ABVS system ultrasound probe from an Acuson S2000 was integrated into a MAMMOMAT Inspiration (both Siemens Healthcare Ltd) and, with the aid of a newly developed compression plate, digital mammogram and automated 3D ultrasound images were obtained. The quality of digital mammogram images produced by the fusion prototype was comparable to those produced using conventional compression. The newly developed compression plate did not influence the applied x-ray dose. The method was not more labour intensive or time-consuming than conventional mammography. From the technical perspective, fusion of the two modalities was achievable. In this study, using only a few mastectomy specimens, the fusion of an automated 3D ultrasound machine with a standard mammography unit delivered images of comparable quality to conventional mammography. The device allows simultaneous ultrasound - the second important imaging modality in complementary breast diagnostics - without increasing examination time or requiring additional staff.

Development of departmental standard for traceability of measured activity for I-131 therapy capsules used in nuclear medicine.

PubMed

Ravichandran, Ramamoorthy; Binukumar, Jp

2011-01-01

International Basic Safety Standards (International Atomic Energy Agency, IAEA) provide guidance levels for diagnostic procedures in nuclear medicine indicating the maximum usual activity for various diagnostic tests in terms of activities of injected radioactive formulations. An accuracy of ± 10% in the activities of administered radio-pharmaceuticals is being recommended, for expected outcome in diagnostic and therapeutic nuclear medicine procedures. It is recommended that the long-term stability of isotope calibrators used in nuclear medicine is to be checked periodically for their performance using a long-lived check source, such as Cs-137, of suitable activity. In view of the un-availability of such a radioactive source, we tried to develop methods to maintain traceability of these instruments, for certifying measured activities for human use. Two re-entrant chambers [(HDR 1000 and Selectron Source Dosimetry System (SSDS)] with I-125 and Ir-192 calibration factors in the Department of Radiotherapy were used to measure Iodine-131 (I-131) therapy capsules to establish traceability to Mark V isotope calibrator of the Department of Nuclear Medicine. Special nylon jigs were fabricated to keep I-131 capsule holder in position. Measured activities in all the chambers showed good agreement. The accuracy of SSDS chamber in measuring Ir-192 activities in the last 5 years was within 0.5%, validating its role as departmental standard for measuring activity. The above method is adopted because mean energies of I-131 and Ir-192 are comparable.

21 CFR 660.45 - Labeling.

Code of Federal Regulations, 2012 CFR

2012-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.45 Labeling. In... capable of transmitting hepatitis and should be handled accordingly. (d) The package shall include a... test methods, and (3) warnings as to possible hazards, including hepatitis transmitted in handling the...

21 CFR 660.45 - Labeling.

Code of Federal Regulations, 2014 CFR

2014-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.45 Labeling. In... capable of transmitting hepatitis and should be handled accordingly. (d) The package shall include a... test methods, and (3) warnings as to possible hazards, including hepatitis transmitted in handling the...

21 CFR 660.45 - Labeling.

Code of Federal Regulations, 2013 CFR

2013-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.45 Labeling. In... capable of transmitting hepatitis and should be handled accordingly. (d) The package shall include a... test methods, and (3) warnings as to possible hazards, including hepatitis transmitted in handling the...

21 CFR 660.45 - Labeling.

Code of Federal Regulations, 2011 CFR

2011-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.45 Labeling. In... capable of transmitting hepatitis and should be handled accordingly. (d) The package shall include a... test methods, and (3) warnings as to possible hazards, including hepatitis transmitted in handling the...

21 CFR 660.45 - Labeling.

Code of Federal Regulations, 2010 CFR

2010-04-01

... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.45 Labeling. In... capable of transmitting hepatitis and should be handled accordingly. (d) The package shall include a... test methods, and (3) warnings as to possible hazards, including hepatitis transmitted in handling the...

Diagnostic Peptide Discovery: Prioritization of Pathogen Diagnostic Markers Using Multiple Features

PubMed Central

Carmona, Santiago J.; Sartor, Paula A.; Leguizamón, María S.; Campetella, Oscar E.; Agüero, Fernán

2012-01-01

The availability of complete pathogen genomes has renewed interest in the development of diagnostics for infectious diseases. Synthetic peptide microarrays provide a rapid, high-throughput platform for immunological testing of potential B-cell epitopes. However, their current capacity prevent the experimental screening of complete “peptidomes”. Therefore, computational approaches for prediction and/or prioritization of diagnostically relevant peptides are required. In this work we describe a computational method to assess a defined set of molecular properties for each potential diagnostic target in a reference genome. Properties such as sub-cellular localization or expression level were evaluated for the whole protein. At a higher resolution (short peptides), we assessed a set of local properties, such as repetitive motifs, disorder (structured vs natively unstructured regions), trans-membrane spans, genetic polymorphisms (conserved vs. divergent regions), predicted B-cell epitopes, and sequence similarity against human proteins and other potential cross-reacting species (e.g. other pathogens endemic in overlapping geographical locations). A scoring function based on these different features was developed, and used to rank all peptides from a large eukaryotic pathogen proteome. We applied this method to the identification of candidate diagnostic peptides in the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. We measured the performance of the method by analyzing the enrichment of validated antigens in the high-scoring top of the ranking. Based on this measure, our integrative method outperformed alternative prioritizations based on individual properties (such as B-cell epitope predictors alone). Using this method we ranked 10 million 12-mer overlapping peptides derived from the complete T. cruzi proteome. Experimental screening of 190 high-scoring peptides allowed the identification of 37 novel epitopes with diagnostic potential, while none of the low scoring peptides showed significant reactivity. Many of the metrics employed are dependent on standard bioinformatic tools and data, so the method can be easily extended to other pathogen genomes. PMID:23272069

An evidence-based diagnostic classification system for low back pain

PubMed Central

Vining, Robert; Potocki, Eric; Seidman, Michael; Morgenthal, A. Paige

2013-01-01

Introduction: While clinicians generally accept that musculoskeletal low back pain (LBP) can arise from specific tissues, it remains difficult to confirm specific sources. Methods: Based on evidence supported by diagnostic utility studies, doctors of chiropractic functioning as members of a research clinic created a diagnostic classification system, corresponding exam and checklist based on strength of evidence, and in-office efficiency. Results: The diagnostic classification system contains one screening category, two pain categories: Nociceptive, Neuropathic, one functional evaluation category, and one category for unknown or poorly defined diagnoses. Nociceptive and neuropathic pain categories are each divided into 4 subcategories. Conclusion: This article describes and discusses the strength of evidence surrounding diagnostic categories for an in-office, clinical exam and checklist tool for LBP diagnosis. The use of a standardized tool for diagnosing low back pain in clinical and research settings is encouraged. PMID:23997245

Painless Jaundice Caused by Clonorchis sinensis Infection: A Case Report.

PubMed

Hao, Yuhua; Bao, Wanguo; Jin, Meishan; Li, Yuxiang; Wang, Feng

2016-06-01

A man with only yellowing of the skin and eye sclera was diagnosed with clonorchiasis, which rarely manifested jaundice as the initial symptom. However, because of a lack of evidence for a diagnostic gold standard, the time until definitive diagnosis was more than a week. The diagnostic process relied on inquiring about the patient's history, including the place of residence, dietary habits, and symptoms, as well as on serological findings, an imaging examination, and pathological findings. MRCP and CT results showed mild dilatation of intrahepatic ducts and increased periductal echogenicity. The eggs were ultimately found in stool by water sedimentation method after the negative report through direct smear. DNA sequencing of PCR production of the eggs demonstrated 98-100% homology with ITS2 of Clonorchis sinensis. After anti-parasite medical treatment, the patient's symptoms were gradually relieved. Throughout the diagnostic procedure, besides routine examinations, the sedimentation method or concentration method could be used as a sensitive way for both light and heavy C. sinensis infection in the definite diagnosis.

Brain collection, standardized neuropathologic assessment, and comorbidity in ADNI participants

PubMed Central

Franklin, Erin E.; Perrin, Richard J.; Vincent, Benjamin; Baxter, Michael; Morris, John C.; Cairns, Nigel J.

2015-01-01

Introduction The Alzheimer’s Disease Neuroimaging Initiative Neuropathology Core (ADNI-NPC) facilitates brain donation, ensures standardized neuropathologic assessments, and maintains a tissue resource for research. Methods The ADNI-NPC coordinates with performance sites to promote autopsy consent, facilitate tissue collection and autopsy administration, and arrange sample delivery to the NPC, for assessment using NIA-AA neuropathologic diagnostic criteria. Results The ADNI-NPC has obtained 45 participant specimens and neuropathologic assessments have been completed in 36 to date. Challenges in obtaining consent at some sites have limited the voluntary autopsy rate to 58%. Among assessed cases, clinical diagnostic accuracy for Alzheimer disease (AD) is 97%; however, 58% show neuropathologic comorbidities. Discussion Challenges facing autopsy consent and coordination are largely resource-related. The neuropathologic assessments indicate that ADNI’s clinical diagnostic accuracy for AD is high; however, many AD cases have comorbidities that may impact the clinical presentation, course, and imaging and biomarker results. These neuropathologic data permit multimodal and genetic studies of these comorbidities to improve diagnosis and provide etiologic insights. PMID:26194314

Meta-analysis of diagnostic tests accounting for disease prevalence: a new model using trivariate copulas.

PubMed

Hoyer, A; Kuss, O

2015-05-20

In real life and somewhat contrary to biostatistical textbook knowledge, sensitivity and specificity (and not only predictive values) of diagnostic tests can vary with the underlying prevalence of disease. In meta-analysis of diagnostic studies, accounting for this fact naturally leads to a trivariate expansion of the traditional bivariate logistic regression model with random study effects. In this paper, a new model is proposed using trivariate copulas and beta-binomial marginal distributions for sensitivity, specificity, and prevalence as an expansion of the bivariate model. Two different copulas are used, the trivariate Gaussian copula and a trivariate vine copula based on the bivariate Plackett copula. This model has a closed-form likelihood, so standard software (e.g., SAS PROC NLMIXED) can be used. The results of a simulation study have shown that the copula models perform at least as good but frequently better than the standard model. The methods are illustrated by two examples. Copyright © 2015 John Wiley & Sons, Ltd.

Case Definitions, Diagnostic Algorithms, and Priorities in Encephalitis: Consensus Statement of the International Encephalitis Consortium

PubMed Central

Venkatesan, A.; Tunkel, A. R.; Bloch, K. C.; Lauring, A. S.; Sejvar, J.; Bitnun, A.; Stahl, J-P.; Mailles, A.; Drebot, M.; Rupprecht, C. E.; Yoder, J.; Cope, J. R.; Wilson, M. R.; Whitley, R. J.; Sullivan, J.; Granerod, J.; Jones, C.; Eastwood, K.; Ward, K. N.; Durrheim, D. N.; Solbrig, M. V.; Guo-Dong, L.; Glaser, C. A.; Sheriff, Heather; Brown, David; Farnon, Eileen; Messenger, Sharon; Paterson, Beverley; Soldatos, Ariane; Roy, Sharon; Visvesvara, Govinda; Beach, Michael; Nasci, Roger; Pertowski, Carol; Schmid, Scott; Rascoe, Lisa; Montgomery, Joel; Tong, Suxiang; Breiman, Robert; Franka, Richard; Keuhnert, Matt; Angulo, Fred; Cherry, James

2013-01-01

Background.Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research. Methods.In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study. Results.We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed. Conclusions.We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis. PMID:23861361

[Diagnostic kits in parasitology: which controls?].

PubMed

Rossi, P

2004-06-01

The development of new diagnostic tools particularly for some parasitic "neglected diseases", is slowed or even hindered by limited resources assigned for basic and applied research in public institution and private sector. Even if the time-line and costs needed for developing a new In Vitro Diagnostic (IVD) test are generally lower compared to vaccines or new drugs, industry is poorly engaged in investing resources due to the perception of limited markets. To accelerate the development of diagnostics for the world's most deadly diseases, the World Health Organization's (WHO) Special Programme for Research and Training in Tropical Diseases (TDR), the United Nations Development Programme, the World Bank and the Gates Foundation, last year launched a new initiative, FIND (Foundation for Innovative New Diagnostics, www.finddiagnostics.org). The aim is to "apply the latest biotechnology innovations to develop and validate affordable diagnostic tests for diseases of the developing world". Ideally, a new diagnostic test should be accurately evaluated prior to use in medical practice. The first step would be a pre-clinical evaluation, an analytic study to determine its laboratory performance. A crucial point in this phase is the calibration of reagents (antigens, antibodies, DNA probes, etc.) against a standard reference preparation. WHO, through the WHO International Laboratories for Biological Standards, "provides International Biological Reference Preparations which serve as reference sources of defined biological activity expressed in an internationally agreed unit" (www.who.int/biologicals/IBRP/index.htm). Standardization allows "comparison of biological measurements worldwide" and ensures the reliability of diagnostic procedures. These preparations are generally intended for use in the characterization of the activity of secondary reference preparations (regional, national or in-house working standards). Unfortunately, international reference standards for parasitic diseases are not available at present, except for Toxoplasma antibodies. The first international standard reagent for Anti-Toxoplasma Serum was established in 1968 and at present, an international standard reference serum, Anti-toxoplasma serum, human TOXM is available at the National Institute for Biological Standards and Control (NIBSC) in UK. Several collaborative, multicenter studies were carried out to assess the performance of different methods and commercial tests for the diagnosis of toxoplasmosis, by providing to participating laboratories a panel of well-defined sera to be tested. A four-phase process following well-accepted methodological standards for the development of diagnostics, analogous to those internationally accepted for drugs and vaccines was recently proposed. The pre-clinical evaluation, the analytic study to assess sensitivity, specificity, predictive values in laboratory (phase I), should be followed by a proof of principle study to distinguish diseased from healthy persons in easily accessible populations (phase II). The evaluation of test performance in populations of intended use (phase III), and finally the delineation of cost-effectiveness and societal impact of new tests in comparison with existing tools (phase IV) should complete the validation procedure. In this context, national regulatory agencies play a major role in pre-market approval and post-market surveillance of IVDs. The European Community in 1998 approved a directive (Directive 98/79/EC) which rules the marketing of IVD medical devices, in order to harmonise the performance levels and standards in European countries. But, among IVDs for parasitic diseases, only those to detect congenital toxoplasmosis are submitted to defined procedures to provide the verification of products before their placing on the market and the surveillance after their marketing by a notified body, which perform appropriate examinations, tests and inspections to production facilities to verify if the device meets the requirements of the directive. In U.S.A., the Food and Drug Administration (FDA), through the Office of In Vitro Diagnostic Device Evaluation and Safety (OIVD), provides a comprehensive and regulatory activity for IVDs through pre-market evaluation and post-market surveillance. In developing countries, the scarcity of resources limits the procedures through which the national control authority can assure safety, quality and efficacy of products marketed, both imported and locally manufactured.

Source localization of rhythmic ictal EEG activity: a study of diagnostic accuracy following STARD criteria.

PubMed

Beniczky, Sándor; Lantz, Göran; Rosenzweig, Ivana; Åkeson, Per; Pedersen, Birthe; Pinborg, Lars H; Ziebell, Morten; Jespersen, Bo; Fuglsang-Frederiksen, Anders

2013-10-01

Although precise identification of the seizure-onset zone is an essential element of presurgical evaluation, source localization of ictal electroencephalography (EEG) signals has received little attention. The aim of our study was to estimate the accuracy of source localization of rhythmic ictal EEG activity using a distributed source model. Source localization of rhythmic ictal scalp EEG activity was performed in 42 consecutive cases fulfilling inclusion criteria. The study was designed according to recommendations for studies on diagnostic accuracy (STARD). The initial ictal EEG signals were selected using a standardized method, based on frequency analysis and voltage distribution of the ictal activity. A distributed source model-local autoregressive average (LAURA)-was used for the source localization. Sensitivity, specificity, and measurement of agreement (kappa) were determined based on the reference standard-the consensus conclusion of the multidisciplinary epilepsy surgery team. Predictive values were calculated from the surgical outcome of the operated patients. To estimate the clinical value of the ictal source analysis, we compared the likelihood ratios of concordant and discordant results. Source localization was performed blinded to the clinical data, and before the surgical decision. Reference standard was available for 33 patients. The ictal source localization had a sensitivity of 70% and a specificity of 76%. The mean measurement of agreement (kappa) was 0.61, corresponding to substantial agreement (95% confidence interval (CI) 0.38-0.84). Twenty patients underwent resective surgery. The positive predictive value (PPV) for seizure freedom was 92% and the negative predictive value (NPV) was 43%. The likelihood ratio was nine times higher for the concordant results, as compared with the discordant ones. Source localization of rhythmic ictal activity using a distributed source model (LAURA) for the ictal EEG signals selected with a standardized method is feasible in clinical practice and has a good diagnostic accuracy. Our findings encourage clinical neurophysiologists assessing ictal EEGs to include this method in their armamentarium. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Epidemiology of angina pectoris: role of natural language processing of the medical record

PubMed Central

Pakhomov, Serguei; Hemingway, Harry; Weston, Susan A.; Jacobsen, Steven J.; Rodeheffer, Richard; Roger, Véronique L.

2007-01-01

Background The diagnosis of angina is challenging as it relies on symptom descriptions. Natural language processing (NLP) of the electronic medical record (EMR) can provide access to such information contained in free text that may not be fully captured by conventional diagnostic coding. Objective To test the hypothesis that NLP of the EMR improves angina pectoris (AP) ascertainment over diagnostic codes. Methods Billing records of in- and out-patients were searched for ICD-9 codes for AP, chronic ischemic heart disease and chest pain. EMR clinical reports were searched electronically for 50 specific non-negated natural language synonyms to these ICD-9 codes. The two methods were compared to a standardized assessment of angina by Rose questionnaire for three diagnostic levels: unspecified chest pain, exertional chest pain, and Rose angina. Results Compared to the Rose questionnaire, the true positive rate of EMR-NLP for unspecified chest pain was 62% (95%CI:55–67) vs. 51% (95%CI:44–58) for diagnostic codes (p<0.001). For exertional chest pain, the EMR-NLP true positive rate was 71% (95%CI:61–80) vs. 62% (95%CI:52–73) for diagnostic codes (p=0.10). Both approaches had 88% (95%CI:65–100) true positive rate for Rose angina. The EMR-NLP method consistently identified more patients with exertional chest pain over 28-month follow-up. Conclusion EMR-NLP method improves the detection of unspecified and exertional chest pain cases compared to diagnostic codes. These findings have implications for epidemiological and clinical studies of angina pectoris. PMID:17383310

Assessing operating characteristics of CAD algorithms in the absence of a gold standard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy Choudhury, Kingshuk; Paik, David S.; Yi, Chin A.

2010-04-15

Purpose: The authors examine potential bias when using a reference reader panel as ''gold standard'' for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. Methods: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range ofmore » operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. Results: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value <0.0001) than LCA (ARB -2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). Conclusions: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.« less

[Microbiological point of care tests].

PubMed

Book, Malte; Lehmann, Lutz Eric; Zhang, Xianghong; Stüber, Frank

2010-11-01

It is well known that the early initiation of a specific antiinfective therapy is crucial to reduce the mortality in severe infection. Procedures culturing pathogens are the diagnostic gold standard in such diseases. However, these methods yield results earliest between 24 to 48 hours. Therefore, severe infections such as sepsis need to be treated with an empirical antimicrobial therapy, which is ineffective in an unknown fraction of these patients. Today's microbiological point of care tests are pathogen specific and therefore not appropriate for an infection with a variety of possible pathogens. Molecular nucleic acid diagnostics such as polymerase chain reaction (PCR) allow the identification of pathogens and resistances. These methods are used routinely to speed up the analysis of positive blood cultures. The newest PCR based system allows the identification of the 25 most frequent sepsis pathogens by PCR in parallel without previous culture in less than 6 hours. Thereby, these systems might shorten the time of possibly insufficient antiinfective therapy. However, these extensive tools are not suitable as point of care diagnostics. Miniaturization and automating of the nucleic acid based method is pending, as well as an increase of detectable pathogens and resistance genes by these methods. It is assumed that molecular PCR techniques will have an increasing impact on microbiological diagnostics in the future. © Georg Thieme Verlag Stuttgart · New York.

Comparison of machine learning methods for classifying mediastinal lymph node metastasis of non-small cell lung cancer from 18F-FDG PET/CT images.

PubMed

Wang, Hongkai; Zhou, Zongwei; Li, Yingci; Chen, Zhonghua; Lu, Peiou; Wang, Wenzhi; Liu, Wanyu; Yu, Lijuan

2017-12-01

This study aimed to compare one state-of-the-art deep learning method and four classical machine learning methods for classifying mediastinal lymph node metastasis of non-small cell lung cancer (NSCLC) from 18 F-FDG PET/CT images. Another objective was to compare the discriminative power of the recently popular PET/CT texture features with the widely used diagnostic features such as tumor size, CT value, SUV, image contrast, and intensity standard deviation. The four classical machine learning methods included random forests, support vector machines, adaptive boosting, and artificial neural network. The deep learning method was the convolutional neural networks (CNN). The five methods were evaluated using 1397 lymph nodes collected from PET/CT images of 168 patients, with corresponding pathology analysis results as gold standard. The comparison was conducted using 10 times 10-fold cross-validation based on the criterion of sensitivity, specificity, accuracy (ACC), and area under the ROC curve (AUC). For each classical method, different input features were compared to select the optimal feature set. Based on the optimal feature set, the classical methods were compared with CNN, as well as with human doctors from our institute. For the classical methods, the diagnostic features resulted in 81~85% ACC and 0.87~0.92 AUC, which were significantly higher than the results of texture features. CNN's sensitivity, specificity, ACC, and AUC were 84, 88, 86, and 0.91, respectively. There was no significant difference between the results of CNN and the best classical method. The sensitivity, specificity, and ACC of human doctors were 73, 90, and 82, respectively. All the five machine learning methods had higher sensitivities but lower specificities than human doctors. The present study shows that the performance of CNN is not significantly different from the best classical methods and human doctors for classifying mediastinal lymph node metastasis of NSCLC from PET/CT images. Because CNN does not need tumor segmentation or feature calculation, it is more convenient and more objective than the classical methods. However, CNN does not make use of the import diagnostic features, which have been proved more discriminative than the texture features for classifying small-sized lymph nodes. Therefore, incorporating the diagnostic features into CNN is a promising direction for future research.

Comparison of the diagnostic accuracy of a rapid immunochromatographic test and the rapid plasma reagin test for antenatal syphilis screening in Mozambique.

PubMed Central

Montoya, Pablo J.; Lukehart, Sheila A.; Brentlinger, Paula E.; Blanco, Ana J.; Floriano, Florencia; Sairosse, Josefa; Gloyd, Stephen

2006-01-01

OBJECTIVE: Programmes to control syphilis in developing countries are hampered by a lack of laboratory services, delayed diagnosis, and doubts about current screening methods. We aimed to compare the diagnostic accuracy of an immunochromatographic strip (ICS) test and the rapid plasma reagin (RPR) test with the combined gold standard (RPR, Treponema pallidum haemagglutination assay and direct immunofluorescence stain done at a reference laboratory) for the detection of syphilis in pregnancy. METHODS: We included test results from 4789 women attending their first antenatal visit at one of six health facilities in Sofala Province, central Mozambique. We compared diagnostic accuracy (sensitivity, specificity, and positive and negative predictive values) of ICS and RPR done at the health facilities and ICS performed at the reference laboratory. We also made subgroup comparisons by human immunodeficiency virus (HIV) and malaria status. FINDINGS: For active syphilis, the sensitivity of the ICS was 95.3% at the reference laboratory, and 84.1% at the health facility. The sensitivity of the RPR at the health facility was 70.7%. Specificity and positive and negative predictive values showed a similar pattern. The ICS outperformed RPR in all comparisons (P<0.001). CONCLUSION: The diagnostic accuracy of the ICS compared favourably with that of the gold standard. The use of the ICS in Mozambique and similar settings may improve the diagnosis of syphilis in health facilities, both with and without laboratories. PMID:16501726

A standard test case suite for two-dimensional linear transport on the sphere: results from a collection of state-of-the-art schemes

NASA Astrophysics Data System (ADS)

Lauritzen, P. H.; Ullrich, P. A.; Jablonowski, C.; Bosler, P. A.; Calhoun, D.; Conley, A. J.; Enomoto, T.; Dong, L.; Dubey, S.; Guba, O.; Hansen, A. B.; Kaas, E.; Kent, J.; Lamarque, J.-F.; Prather, M. J.; Reinert, D.; Shashkin, V. V.; Skamarock, W. C.; Sørensen, B.; Taylor, M. A.; Tolstykh, M. A.

2013-09-01

Recently, a standard test case suite for 2-D linear transport on the sphere was proposed to assess important aspects of accuracy in geophysical fluid dynamics with a "minimal" set of idealized model configurations/runs/diagnostics. Here we present results from 19 state-of-the-art transport scheme formulations based on finite-difference/finite-volume methods as well as emerging (in the context of atmospheric/oceanographic sciences) Galerkin methods. Discretization grids range from traditional regular latitude-longitude grids to more isotropic domain discretizations such as icosahedral and cubed-sphere tessellations of the sphere. The schemes are evaluated using a wide range of diagnostics in idealized flow environments. Accuracy is assessed in single- and two-tracer configurations using conventional error norms as well as novel diagnostics designed for climate and climate-chemistry applications. In addition, algorithmic considerations that may be important for computational efficiency are reported on. The latter is inevitably computing platform dependent, The ensemble of results from a wide variety of schemes presented here helps shed light on the ability of the test case suite diagnostics and flow settings to discriminate between algorithms and provide insights into accuracy in the context of global atmospheric/ocean modeling. A library of benchmark results is provided to facilitate scheme intercomparison and model development. Simple software and data-sets are made available to facilitate the process of model evaluation and scheme intercomparison.

A standard test case suite for two-dimensional linear transport on the sphere: results from a collection of state-of-the-art schemes

NASA Astrophysics Data System (ADS)

Lauritzen, P. H.; Ullrich, P. A.; Jablonowski, C.; Bosler, P. A.; Calhoun, D.; Conley, A. J.; Enomoto, T.; Dong, L.; Dubey, S.; Guba, O.; Hansen, A. B.; Kaas, E.; Kent, J.; Lamarque, J.-F.; Prather, M. J.; Reinert, D.; Shashkin, V. V.; Skamarock, W. C.; Sørensen, B.; Taylor, M. A.; Tolstykh, M. A.

2014-01-01

Recently, a standard test case suite for 2-D linear transport on the sphere was proposed to assess important aspects of accuracy in geophysical fluid dynamics with a "minimal" set of idealized model configurations/runs/diagnostics. Here we present results from 19 state-of-the-art transport scheme formulations based on finite-difference/finite-volume methods as well as emerging (in the context of atmospheric/oceanographic sciences) Galerkin methods. Discretization grids range from traditional regular latitude-longitude grids to more isotropic domain discretizations such as icosahedral and cubed-sphere tessellations of the sphere. The schemes are evaluated using a wide range of diagnostics in idealized flow environments. Accuracy is assessed in single- and two-tracer configurations using conventional error norms as well as novel diagnostics designed for climate and climate-chemistry applications. In addition, algorithmic considerations that may be important for computational efficiency are reported on. The latter is inevitably computing platform dependent. The ensemble of results from a wide variety of schemes presented here helps shed light on the ability of the test case suite diagnostics and flow settings to discriminate between algorithms and provide insights into accuracy in the context of global atmospheric/ocean modeling. A library of benchmark results is provided to facilitate scheme intercomparison and model development. Simple software and data sets are made available to facilitate the process of model evaluation and scheme intercomparison.

Magnetic Resonance Angiography in the Diagnosis of Cerebral Arteriovenous Malformation and Dural Arteriovenous Fistulas: Comparison of Time-Resolved Magnetic Resonance Angiography and Three Dimensional Time-of-Flight Magnetic Resonance Angiography

PubMed Central

Cheng, Yu-Ching; Chen, Hung-Chieh; Wu, Chen-Hao; Wu, Yi-Ying; Sun, Ming-His; Chen, Wen-Hsien; Chai, Jyh-Wen; Chi-Chang Chen, Clayton

2016-01-01

Background Traditional digital subtraction angiography (DSA) is currently the gold standard diagnostic method for the diagnosis and evaluation of cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (dAVF). Objectives The aim of this study was to analyze different less invasive magnetic resonance angiography (MRA) images, time-resolved MRA (TR-MRA) and three-dimensional time-of-flight MRA (3D TOF MRA) to identify their diagnostic accuracy and to determine which approach is most similar to DSA. Patients and Methods A total of 41 patients with AVM and dAVF at their initial evaluation or follow-up after treatment were recruited in this study. We applied time-resolved angiography using keyhole (4D-TRAK) MRA to perform TR-MRA and 3D TOF MRA examinations simultaneously followed by DSA, which was considered as a standard reference. Two experienced neuroradiologists reviewed the images to compare the diagnostic accuracy, arterial feeder and venous drainage between these two MRA images. Inter-observer agreement for different MRA images was assessed by Kappa coefficient and the differences of diagnostic accuracy between MRA images were evaluated by the Wilcoxon rank sum test. Results Almost all vascular lesions (92.68%) were correctly diagnosed using 4D-TRAK MRA. However, 3D TOF MRA only diagnosed 26 patients (63.41%) accurately. There were statistically significant differences regarding lesion diagnostic accuracy (P = 0.008) and venous drainage identification (P < 0.0001) between 4D-TRAK MRA and 3D TOF MRA. The results indicate that 4D-TRAK MRA is superior to 3D TOF MRA in the assessment of lesions. Conclusion Compared with 3D TOF MRA, 4D-TRAK MRA proved to be a more reliable screening modality and follow-up method for the diagnosis of cerebral AVM and dAVF. PMID:27679690

Evaluation of the diagnostic accuracy of CareStart G6PD deficiency Rapid Diagnostic Test (RDT) in a malaria endemic area in Ghana, Africa.

PubMed

Adu-Gyasi, Dennis; Asante, Kwaku Poku; Newton, Sam; Dosoo, David; Amoako, Sabastina; Adjei, George; Amoako, Nicholas; Ankrah, Love; Tchum, Samuel Kofi; Mahama, Emmanuel; Agyemang, Veronica; Kayan, Kingsley; Owusu-Agyei, Seth

2015-01-01

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most widespread enzyme defect that can result in red cell breakdown under oxidative stress when exposed to certain medicines including antimalarials. We evaluated the diagnostic accuracy of CareStart G6PD deficiency Rapid Diagnostic Test (RDT) as a point-of-care tool for screening G6PD deficiency. A cross-sectional study was conducted among 206 randomly selected and consented participants from a group with known G6PD deficiency status between February 2013 and June 2013. A maximum of 1.6ml of capillary blood samples were used for G6PD deficiency screening using CareStart G6PD RDT and Trinity qualitative with Trinity quantitative methods as the "gold standard". Samples were also screened for the presence of malaria parasites. Data entry and analysis were done using Microsoft Access 2010 and Stata Software version 12. Kintampo Health Research Centre Institutional Ethics Committee granted ethical approval. The sensitivity (SE) and specificity (SP) of CareStart G6PD deficiency RDT was 100% and 72.1% compared to Trinity quantitative method respectively and was 98.9% and 96.2% compared to Trinity qualitative method. Malaria infection status had no significant (P=0.199) change on the performance of the G6PD RDT test kit compared to the "gold standard". The outcome of this study suggests that the diagnostic performance of the CareStart G6PD deficiency RDT kit was high and it is acceptable at determining the G6PD deficiency status in a high malaria endemic area in Ghana. The RDT kit presents as an attractive tool for point-of-care G6PD deficiency for rapid testing in areas with high temperatures and less expertise. The CareStart G6PD deficiency RDT kit could be used to screen malaria patients before administration of the fixed dose primaquine with artemisinin-based combination therapy.

Standard echocardiography versus handheld echocardiography for the detection of subclinical rheumatic heart disease: protocol for a systematic review

PubMed Central

Telford, Lisa H; Abdullahi, Leila H; Ochodo, Eleanor A; Engel, Mark E

2018-01-01

Introduction Rheumatic heart disease (RHD) is a preventable and treatable chronic condition which persists in many developing countries largely affecting impoverished populations. Handheld echocardiography presents an opportunity to address the need for more cost-effective methods of diagnosing RHD in developing countries, where the disease continues to carry high rates of morbidity and mortality. Preliminary studies have demonstrated moderate sensitivity as well as high specificity and diagnostic odds for detecting RHD in asymptomatic patients. We describe a protocol for a systematic review on the diagnostic performance of handheld echocardiography compared to standard echocardiography using the 2012 World Heart Federation criteria for diagnosing subclinical RHD. Methods and analysis Electronic databases including PubMed, Scopus, Web of Science and EBSCOhost as well as reference lists and citations of relevant articles will be searched from 2012 to date using a predefined strategy incorporating a combination of Medical Subject Heading terms and keywords. The methodological validity and quality of studies deemed eligible for inclusion will be assessed against review specific Quality Assessment of Diagnostic Accuracy Studies 2 criteria and information on metrics of diagnostic accuracy and demographics extracted. Forest plots of sensitivity and specificity as well as scatter plots in receiver operating characteristic (ROC) space will be used to investigate heterogeneity. If possible, a meta-analysis will be conducted to produce summary results of sensitivity and specificity using the Hierarchical Summary ROC method. In addition, a sensitivity analysis will be conducted to investigate the effect of studies with a high risk of bias. Ethics and dissemination Ethics approval is not required for this systematic review of previously published literature. The planned review will provide a summary of the diagnostic accuracy of handheld echocardiography. Results may feed into evidence-based guidelines and should the findings of this review warrant a change in clinical practice, a summary report will be disseminated among leading clinicians and healthcare professionals in the field. PROSPERO registration number CRD42016051261. PMID:29440164

Methods specification for diagnostic test accuracy studies in fine-needle aspiration cytology: a survey of reporting practice.

PubMed

Schmidt, Robert L; Factor, Rachel E; Affolter, Kajsa E; Cook, Joshua B; Hall, Brian J; Narra, Krishna K; Witt, Benjamin L; Wilson, Andrew R; Layfield, Lester J

2012-01-01

Diagnostic test accuracy (DTA) studies on fine-needle aspiration cytology (FNAC) often show considerable variability in diagnostic accuracy between study centers. Many factors affect the accuracy of FNAC. A complete description of the testing parameters would help make valid comparisons between studies and determine causes of performance variation. We investigated the manner in which test conditions are specified in FNAC DTA studies to determine which parameters are most commonly specified and the frequency with which they are specified and to see whether there is significant variability in reporting practice. We identified 17 frequently reported test parameters and found significant variation in the reporting of these test specifications across studies. On average, studies reported 5 of the 17 items that would be required to specify the test conditions completely. A more complete and standardized reporting of methods, perhaps by means of a checklist, would improve the interpretation of FNAC DTA studies.

Tomographic diagnostics of nonthermal plasmas

NASA Astrophysics Data System (ADS)

Denisova, Natalia

2009-10-01

In the previous work [1], we discussed a ``technology'' of tomographic method and relations between the tomographic diagnostics in thermal (equilibrium) and nonthermal (nonequilibrium) plasma sources. The conclusion has been made that tomographic reconstruction in thermal plasma sources is the standard procedure at present, which can provide much useful information on the plasma structure and its evolution in time, while the tomographic reconstruction of nonthermal plasma has a great potential at making a contribution to understanding the fundamental problem of substance behavior in strongly nonequilibrium conditions. Using medical terminology, one could say, that tomographic diagnostics of the equilibrium plasma sources studies their ``anatomic'' structure, while reconstruction of the nonequilibrium plasma is similar to the ``physiological'' examination: it is directed to study the physical mechanisms and processes. The present work is focused on nonthermal plasma research. The tomographic diagnostics is directed to study spatial structures formed in the gas discharge plasmas under the influence of electrical and gravitational fields. The ways of plasma ``self-organization'' in changing and extreme conditions are analyzed. The analysis has been made using some examples from our practical tomographic diagnostics of nonthermal plasma sources, such as low-pressure capacitive and inductive discharges. [0pt] [1] Denisova N. Plasma diagnostics using computed tomography method // IEEE Trans. Plasma Sci. 2009 37 4 502.

The role of standards in the development and implementation of clinical laboratory tests: a domestic and global perspective.

PubMed

Michaud, Ginette Y

2005-01-01

In the field of clinical laboratory medicine, standardization is aimed at increasing the trueness and reliability of measured values. Standardization relies on the use of written standards, reference measurement procedures and reference materials. These are important tools for the design and validation of new tests, and for establishing the metrological traceability of diagnostic assays. Their use supports the translation of research technologies into new diagnostic assays and leads to more rapid advances in science and medicine, as well as improvements in the quality of patient care. The various standardization tools are described, as are the procedures by which written standards, reference procedures and reference materials are developed. Recent efforts to develop standards for use in the field of molecular diagnostics are discussed. The recognition of standardization tools by the FDA and other regulatory authorities is noted as evidence of their important role in ensuring the safety and performance of in vitro diagnostic devices.

The convergence of personality disorder diagnoses across different methods among monolingual (Spanish-speaking only) Hispanic patients in substance use treatment.

PubMed

Samuel, Douglas B; Añez, Luis M; Paris, Manuel; Grilo, Carlos M

2014-04-01

Methods for diagnosing personality disorders (PDs) within clinical settings typically diverge from those used in treatment research. Treatment groups in research studies are routinely diagnosed using semistructured interviews or self-report questionnaires, yet these methods show poor agreement with clinical diagnoses recorded in medical charts or assigned by treating clinicians, reducing the potential for evidence-based practice. Furthermore, existing research has been limited by focusing on primarily White and English-speaking participants. Our study extended prior research by comparing 4 independent methods of PD diagnosis, including self-report questionnaire, semistructured interview, chart diagnoses, and ratings by treating clinicians, within a clinical series of 130 monolingual (Spanish only) Hispanic persons (69% male; M age 37.4), in treatment for substance use. The authors examined the convergence of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) PD diagnoses across these methods. PD diagnoses appeared infrequently within medical charts but were diagnosed at higher levels by independent treating clinicians, self-report questionnaires, and semistructured interviews. Nonetheless, diagnostic concordance between clinical diagnoses and the other methods were poor (κ < .20). Convergence of PD diagnoses across diagnostic methods for Spanish-speaking Hispanic persons are comparable to other groups allaying concerns about cross-cultural application of PD diagnoses. Additionally, the results of this study echo previous research in suggesting that clinicians' PD diagnoses overlap little with self-report questionnaires or semistructured diagnostic interviews and suggest that PDs are underdiagnosed using standard diagnostic approaches. Implications for the clinical application of empirically supported research are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved

A diagnostic approach in Alzheimer`s disease using three-dimensional stereotactic surface projections of Fluorine-18-FDG PET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minoshima, S.; Frey, K.A.; Koeppe, R.A.

1995-07-01

To improve the diagnostic performance of PET as an aid in evaluating patients suspected of having Alzheimer`s disease, the authors developed a fully automated method which generates comprehensive image presentations and objective diagnostic indices. Fluorine-18-fluorodeoxyglucose PET image sets were collected from 37 patients with probable Alzheimer`s disease (including questionable and mild dementia), 22 normal subjects and 5 patients with cerebrovascular disease. Following stereotactic anatomic standardization, metabolic activity on an individual`s PET image set was extracted to a set of predefined surface pixels (three-dimensional stereotactic surface projection, 3D-SSP), which was used in the subsequent analysis. A normal database was created bymore » averaging extracted datasets of the normal subjects. Patients` datasets were compared individually with the normal database by calculating a Z-score on a pixel-by-pixel basis and were displayed in 3D-SSP views for visual inspections. Diagnostic indices were then generated based on averaged Z-scores for the association cortices. Patterns and severities of metabolic reduction in patients with probable Alzheimer`s disease were seen in the standard 3D-SSP views of extracted raw data and statistical Z-scores. When discriminating patients with probable Alzheimer`s disease from normal subjects, diagnostic indices of the parietal association cortex and unilaterally averaged parietal-temporal-frontal cortex showed sensitivities of 95% and 97%, respectively, with a specificity of 100%. Neither index yielded false-positive results for cerebrovascular disease. 3D-SSP enables quantitative data extraction and reliable localization of metabolic abnormalities by means of stereotactic coordinates. The proposed method is a promising approach for interpreting functional brain PET scans. 45 refs., 5 figs.« less

Improved detection of Burkholderia pseudomallei from non-blood clinical specimens using enrichment culture and PCR: narrowing diagnostic gap in resource-constrained settings.

PubMed

Tellapragada, Chaitanya; Shaw, Tushar; D'Souza, Annet; Eshwara, Vandana Kalwaje; Mukhopadhyay, Chiranjay

2017-07-01

To evaluate the diagnostic utility of enrichment culture and PCR for improved case detection rates of non-bacteraemic form of melioidosis in limited resource settings. Clinical specimens (n = 525) obtained from patients presenting at a tertiary care hospital of South India with clinical symptoms suggestive of community-acquired pneumonia, lower respiratory tract infections, superficial or internal abscesses, chronic skin ulcers and bone or joint infections were tested for the presence of Burkholderia pseudomallei using conventional culture (CC), enrichment culture (EC) and PCR. Sensitivity, specificity, positive and negative predictive values of CC and PCR were initially deduced using EC as the gold standard method. Further, diagnostic accuracies of all the three methods were analysed using Bayesian latent class modelling (BLCM). Detection rates of B. pseudomallei using CC, EC and PCR were 3.8%, 5.3% and 6%, respectively. Diagnostic sensitivities and specificities of CC and PCR were 71.4, 98.4% and 100 and 99.4%, respectively in comparison with EC as the gold standard test. With Bayesian latent class modelling, EC and PCR demonstrated sensitivities of 98.7 and 99.3%, respectively, while CC showed a sensitivity of 70.3% for detection of B. pseudomallei. An increase of 1.6% (95% CI: 1.08-4.32%) in the case detection rate of melioidosis was observed in the study population when EC and/or PCR were used in adjunct to the conventional culture technique. Our study findings underscore the diagnostic superiority of enrichment culture and/or PCR over conventional microbiological culture for improved case detection of melioidosis from non-blood clinical specimens. © 2017 John Wiley & Sons Ltd.

Laboratory diagnostics of malaria

NASA Astrophysics Data System (ADS)

Siahaan, L.

2018-03-01

Even now, malaria treatment should only be administered after laboratory confirmation. There are several principal methods for diagnosing malaria. All these methods have their disadvantages.Presumptive treatment of malaria is widely practiced where laboratory tests are not readily available. Microscopy of Giemsa-stained thick and thin blood films remains the gold standard for the diagnosis of malaria infection. The technique of slide preparation, staining and reading are well known and standardized, and so is the estimate of the parasite density and parasite stages. Microscopy is not always available or feasible at primary health services in limited resource settings due to cost, lack of skilled manpower, accessories and reagents required. Rapid diagnostic tests (RDTs) are potential tools for parasite-based diagnosis since the tests are accurate in detecting malaria infections and are easy to use. The test is based on the capture of parasite antigen that released from parasitized red blood cells using monoclonal antibodies prepared against malaria antigen target. Polymerase Chain Reaction (PCR), depend on DNA amplification approaches and have higher sensitivity than microscopy. PCR it is not widely used due to the lack of a standardized methodology, high costs, and the need for highly-trained staff.

Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT)

PubMed Central

Cassiday, Pamela K.; Pawloski, Lucia C.; Tatti, Kathleen M.; Martin, Monte D.; Briere, Elizabeth C.; Tondella, M. Lucia; Martin, Stacey W.

2018-01-01

Introduction The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. Methods Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for ≤ 2 weeks were asked to return in 2–4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods—pertussis culture as the “gold standard,” composite reference standard analysis (CRS), and latent class analysis (LCA). Results Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. Conclusions Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis. PMID:29652945

Controlling the Display of Capsule Endoscopy Video for Diagnostic Assistance

NASA Astrophysics Data System (ADS)

Vu, Hai; Echigo, Tomio; Sagawa, Ryusuke; Yagi, Keiko; Shiba, Masatsugu; Higuchi, Kazuhide; Arakawa, Tetsuo; Yagi, Yasushi

Interpretations by physicians of capsule endoscopy image sequences captured over periods of 7-8 hours usually require 45 to 120 minutes of extreme concentration. This paper describes a novel method to reduce diagnostic time by automatically controlling the display frame rate. Unlike existing techniques, this method displays original images with no skipping of frames. The sequence can be played at a high frame rate in stable regions to save time. Then, in regions with rough changes, the speed is decreased to more conveniently ascertain suspicious findings. To realize such a system, cue information about the disparity of consecutive frames, including color similarity and motion displacements is extracted. A decision tree utilizes these features to classify the states of the image acquisitions. For each classified state, the delay time between frames is calculated by parametric functions. A scheme selecting the optimal parameters set determined from assessments by physicians is deployed. Experiments involved clinical evaluations to investigate the effectiveness of this method compared to a standard-view using an existing system. Results from logged action based analysis show that compared with an existing system the proposed method reduced diagnostic time to around 32.5 ± minutes per full sequence while the number of abnormalities found was similar. As well, physicians needed less effort because of the systems efficient operability. The results of the evaluations should convince physicians that they can safely use this method and obtain reduced diagnostic times.

Diagnostic accuracy of stress perfusion CMR in comparison with quantitative coronary angiography: fully quantitative, semiquantitative, and qualitative assessment.

PubMed

Mordini, Federico E; Haddad, Tariq; Hsu, Li-Yueh; Kellman, Peter; Lowrey, Tracy B; Aletras, Anthony H; Bandettini, W Patricia; Arai, Andrew E

2014-01-01

This study's primary objective was to determine the sensitivity, specificity, and accuracy of fully quantitative stress perfusion cardiac magnetic resonance (CMR) versus a reference standard of quantitative coronary angiography. We hypothesized that fully quantitative analysis of stress perfusion CMR would have high diagnostic accuracy for identifying significant coronary artery stenosis and exceed the accuracy of semiquantitative measures of perfusion and qualitative interpretation. Relatively few studies apply fully quantitative CMR perfusion measures to patients with coronary disease and comparisons to semiquantitative and qualitative methods are limited. Dual bolus dipyridamole stress perfusion CMR exams were performed in 67 patients with clinical indications for assessment of myocardial ischemia. Stress perfusion images alone were analyzed with a fully quantitative perfusion (QP) method and 3 semiquantitative methods including contrast enhancement ratio, upslope index, and upslope integral. Comprehensive exams (cine imaging, stress/rest perfusion, late gadolinium enhancement) were analyzed qualitatively with 2 methods including the Duke algorithm and standard clinical interpretation. A 70% or greater stenosis by quantitative coronary angiography was considered abnormal. The optimum diagnostic threshold for QP determined by receiver-operating characteristic curve occurred when endocardial flow decreased to <50% of mean epicardial flow, which yielded a sensitivity of 87% and specificity of 93%. The area under the curve for QP was 92%, which was superior to semiquantitative methods: contrast enhancement ratio: 78%; upslope index: 82%; and upslope integral: 75% (p = 0.011, p = 0.019, p = 0.004 vs. QP, respectively). Area under the curve for QP was also superior to qualitative methods: Duke algorithm: 70%; and clinical interpretation: 78% (p < 0.001 and p < 0.001 vs. QP, respectively). Fully quantitative stress perfusion CMR has high diagnostic accuracy for detecting obstructive coronary artery disease. QP outperforms semiquantitative measures of perfusion and qualitative methods that incorporate a combination of cine, perfusion, and late gadolinium enhancement imaging. These findings suggest a potential clinical role for quantitative stress perfusion CMR. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Estimation of infection prevalence and sensitivity in a stratified two-stage sampling design employing highly specific diagnostic tests when there is no gold standard.

PubMed

Miller, Ezer; Huppert, Amit; Novikov, Ilya; Warburg, Alon; Hailu, Asrat; Abbasi, Ibrahim; Freedman, Laurence S

2015-11-10

In this work, we describe a two-stage sampling design to estimate the infection prevalence in a population. In the first stage, an imperfect diagnostic test was performed on a random sample of the population. In the second stage, a different imperfect test was performed in a stratified random sample of the first sample. To estimate infection prevalence, we assumed conditional independence between the diagnostic tests and develop method of moments estimators based on expectations of the proportions of people with positive and negative results on both tests that are functions of the tests' sensitivity, specificity, and the infection prevalence. A closed-form solution of the estimating equations was obtained assuming a specificity of 100% for both tests. We applied our method to estimate the infection prevalence of visceral leishmaniasis according to two quantitative polymerase chain reaction tests performed on blood samples taken from 4756 patients in northern Ethiopia. The sensitivities of the tests were also estimated, as well as the standard errors of all estimates, using a parametric bootstrap. We also examined the impact of departures from our assumptions of 100% specificity and conditional independence on the estimated prevalence. Copyright © 2015 John Wiley & Sons, Ltd.

Rapid and effective processing of blood specimens for diagnostic PCR using filter paper and Chelex-100.

PubMed Central

Polski, J M; Kimzey, S; Percival, R W; Grosso, L E

1998-01-01

AIM: To provide a more efficient method for isolating DNA from peripheral blood for use in diagnostic DNA mutation analysis. METHODS: The use of blood impregnated filter paper and Chelex-100 in DNA isolation was evaluated and compared with standard DNA isolation techniques. RESULTS: In polymerase chain reaction (PCR) based assays of five point mutations, identical results were obtained with DNA isolated routinely from peripheral blood and isolated using the filter paper and Chelex-100 method. CONCLUSION: In the clinical setting, this method provides a useful alternative to conventional DNA isolation. It is easily implemented and inexpensive, and provides sufficient, stable DNA for multiple assays. The potential for specimen contamination is reduced because most of the steps are performed in a single microcentrifuge tube. In addition, this method provides for easy storage and transport of samples from the point of acquisition. PMID:9893748

Development of a diagnostic test set to assess agreement in breast pathology: practical application of the Guidelines for Reporting Reliability and Agreement Studies (GRRAS).

PubMed

Oster, Natalia V; Carney, Patricia A; Allison, Kimberly H; Weaver, Donald L; Reisch, Lisa M; Longton, Gary; Onega, Tracy; Pepe, Margaret; Geller, Berta M; Nelson, Heidi D; Ross, Tyler R; Tosteson, Aanna N A; Elmore, Joann G

2013-02-05

Diagnostic test sets are a valuable research tool that contributes importantly to the validity and reliability of studies that assess agreement in breast pathology. In order to fully understand the strengths and weaknesses of any agreement and reliability study, however, the methods should be fully reported. In this paper we provide a step-by-step description of the methods used to create four complex test sets for a study of diagnostic agreement among pathologists interpreting breast biopsy specimens. We use the newly developed Guidelines for Reporting Reliability and Agreement Studies (GRRAS) as a basis to report these methods. Breast tissue biopsies were selected from the National Cancer Institute-funded Breast Cancer Surveillance Consortium sites. We used a random sampling stratified according to woman's age (40-49 vs. ≥50), parenchymal breast density (low vs. high) and interpretation of the original pathologist. A 3-member panel of expert breast pathologists first independently interpreted each case using five primary diagnostic categories (non-proliferative changes, proliferative changes without atypia, atypical ductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma). When the experts did not unanimously agree on a case diagnosis a modified Delphi method was used to determine the reference standard consensus diagnosis. The final test cases were stratified and randomly assigned into one of four unique test sets. We found GRRAS recommendations to be very useful in reporting diagnostic test set development and recommend inclusion of two additional criteria: 1) characterizing the study population and 2) describing the methods for reference diagnosis, when applicable.

Sensitive diagnosis of cutaneous leishmaniasis by lesion swab sampling coupled to qPCR

PubMed Central

ADAMS, EMILY R.; GOMEZ, MARIA ADELAIDA; SCHESKE, LAURA; RIOS, RUBY; MARQUEZ, RICARDO; COSSIO, ALEXANDRA; ALBERTINI, AUDREY; SCHALLIG, HENK; SARAVIA, NANCY GORE

2015-01-01

SUMMARY Variation in clinical accuracy of molecular diagnostic methods for cutaneous leishmaniasis (CL) is commonly observed depending on the sample source, the method of DNA recovery and the molecular test. Few attempts have been made to compare these variables. Two swab and aspirate samples from lesions of patients with suspected CL (n = 105) were evaluated alongside standard diagnosis by microscopic detection of amastigotes or culture of parasites from lesion material. Three DNA extraction methods were compared: Qiagen on swab and aspirate specimens, Isohelix on swabs and Boil/Spin of lesion aspirates. Recovery of Leishmania DNA was evaluated for each sample type by real-time polymerase chain reaction detection of parasitic 18S rDNA, and the diagnostic accuracy of the molecular method determined. Swab sampling combined with Qiagen DNA extraction was the most efficient recovery method for Leishmania DNA, and was the most sensitive (98%; 95% CI: 91–100%) and specific (84%; 95% CI: 64–95%) approach. Aspirated material was less sensitive at 80% (95% CI: 70–88%) and 61% (95% CI: 50–72%) when coupled to Qiagen or Boil-Spin DNA extraction, respectively. Swab sampling of lesions was painless, simple to perform and coupled with standardized DNA extraction enhances the feasibility of molecular diagnosis of CL. PMID:25111885

3D-CAM: Derivation and Validation of a 3-Minute Diagnostic Interview for CAM-defined Delirium

PubMed Central

Marcantonio, Edward R.; Ngo, Long H.; O’Connor, Margaret; Jones, Richard N.; Crane, Paul K.; Metzger, Eran D.; Inouye, Sharon K.

2015-01-01

Background Delirium is common, morbid, and costly, yet remains often unrecognized in most clinical settings. The Confusion Assessment Method (CAM) is the most widely used diagnostic algorithm, and operationalizing its features would represent a substantial advance for clinical care. Objective To derive the 3D-CAM, a new 3-minute diagnostic assessment for CAM-defined delirium, and to validate it against a clinical reference standard. Design Diagnostic test study Setting 4 general medicine units in an academic medical center Participants 201 inpatients aged ≥ 75 years old Measurements We identified 20 items that best operationalized the 4 CAM diagnostic features to create the 3D-CAM. For prospective validation, 3D-CAM assessments were administered by trained research assistants. Independently, clinicians performed an extensive assessment that included patient interviews, family interviews, and review of the medical record. These data were considered by an expert panel to determine the presence or absence of delirium and dementia (reference standard). We compared the 3D-CAM delirium determination to the reference standard in all patients and in subgroups with and without dementia. Results The 201 participants in the prospective validation study had mean age (SD) of 84 (5.5) years, and 27% had dementia. The expert panel identified delirium in 21%. Median administration time for 3D-CAM was 3 minutes (inter-quartile range: 2–5 minutes). The sensitivity [95% CI] of 3D-CAM was 95% [84%, 99%] and the specificity was 94% [90%, 97%]. The 3D-CAM performed well in patients both with dementia (sensitivity=96% [82%, 100%], specificity=86% [67%, 96%]) and without dementia (sensitivity=93% [66%, 100%], specificity=96% [91%,99%]). Limitations Limited to single center, cross-sectional, and medicine patients only Conclusion The 3D-CAM operationalizes the CAM algorithm using a 3-minute structured assessment with high sensitivity and specificity relative to a reference standard and could be an important tool for improving recognition of delirium. PMID:25329203

Open Energy Information System version 2.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

OpenEIS was created to provide standard methods for authoring, sharing, testing, using, and improving algorithms for operational building energy efficiency with building managers and building owners. OpenEIS is designed as a no-cost/low-cost solution that will propagate the fault detection and diagnostic (FDD) solutions into the marketplace by providing state- of- the-art analytical and diagnostic algorithms. As OpenEIS penetrates the market, demand by control system manufacturers and integrators serving small and medium commercial customers will help push these types of commercial software tool offerings into the broader marketplace.

Predictors and Diagnostic Significance of the Adenosine Related Side Effects on Myocardial Perfusion SPECT/CT Imaging

PubMed Central

Yıldırım Poyraz, Nilüfer; Özdemir, Elif; Poyraz, Barış Mustafa; Kandemir, Zuhal; Keskin, Mutlay; Türkölmez, Şeyda

2014-01-01

Objective: The aim of this study was to investigate the relationship between patient characteristics and adenosine-related side-effects during stress myocard perfusion imaging (MPI). The effect of presence of adenosine-related side-effects on the diagnostic value of MPI with integrated SPECT/CT system for coronary artery disease (CAD), was also assessed in this study. Methods: Total of 281 patients (109 M, 172 F; mean age:62.6±10) who underwent standard adenosine stress protocol for MPI, were included in this study. All symptoms during adenosine infusion were scored according to the severity and duration. For the estimation of diagnostic value of adenosine MPI with integrated SPECT/CT system, coronary angiography (CAG) or clinical follow-up were used as gold standard. Results: Total of 173 patients (61.6%) experienced adenosine-related side-effects (group 1); flushing, dyspnea, and chest pain were the most common. Other 108 patients completed pharmacologic stress (PS) test without any side-effects (group 2). Test tolerability were similar in the patients with cardiovascular or airway disease to others, however dyspnea were observed significantly more common in patients with mild airway disease. Body mass index (BMI) ≥30 kg/m2 and age ≤45 years were independent predictors of side-effects. The diagnostic value of MPI was similar in both groups. Sensitivity of adenosine MPI SPECT/CT was calculated to be 86%, specificity was 94% and diagnostic accuracy was 92% for diagnosis of CAD. Conclusion: Adenosine MPI is a feasible and well tolerated method in patients who are not suitable for exercise stress test as well as patients with cardiopulmonary disease. However age ≤45 years and BMI ≥30 kg/m2 are the positive predictors of adenosine-related side-effects, the diagnostic value of adenosine MPI SPECT/CT is not affected by the presence of adenosine related side-effects. PMID:25541932

Toward unbiased estimations of the statefinder parameters

NASA Astrophysics Data System (ADS)

Aviles, Alejandro; Klapp, Jaime; Luongo, Orlando

2017-09-01

With the use of simulated supernova catalogs, we show that the statefinder parameters turn out to be poorly and biased estimated by standard cosmography. To this end, we compute their standard deviations and several bias statistics on cosmologies near the concordance model, demonstrating that these are very large, making standard cosmography unsuitable for future and wider compilations of data. To overcome this issue, we propose a new method that consists in introducing the series of the Hubble function into the luminosity distance, instead of considering the usual direct Taylor expansions of the luminosity distance. Moreover, in order to speed up the numerical computations, we estimate the coefficients of our expansions in a hierarchical manner, in which the order of the expansion depends on the redshift of every single piece of data. In addition, we propose two hybrids methods that incorporates standard cosmography at low redshifts. The methods presented here perform better than the standard approach of cosmography both in the errors and bias of the estimated statefinders. We further propose a one-parameter diagnostic to reject non-viable methods in cosmography.

A Novel Field Deployable Point-of-Care Diagnostic Test for Cutaneous Leishmaniasis

DTIC Science & Technology

2015-10-01

include localized cutaneous leishmaniasis (LCL), and destructive nasal and oropharyngeal lesions of mucosal leishmaniasis (ML). LCL in the New World...the high costs, personnel training and need of sophisticated equipment. Therefore, novel methods to detect leishmaniasis at the POC are urgently needed...To date, there is no field-standardized molecular method based on DNA amplification coupled with Lateral Flow reading to detect leishmaniasis

Nasal potential difference measurements in diagnosis of cystic fibrosis: an international survey.

PubMed

Naehrlich, Lutz; Ballmann, Manfred; Davies, Jane; Derichs, Nico; Gonska, Tanja; Hjelte, Lena; van Konigsbruggen-Rietschel, Silke; Leal, Teresinha; Melotti, Paola; Middleton, Peter; Tümmler, Burkhard; Vermeulen, Francois; Wilschanski, Michael

2014-01-01

The role of nasal potential difference (NPD) measurement as a diagnostic test for cystic fibrosis (CF) is a subject of global controversy because of the lack of validation studies, clear reference values, and standardized protocols for diagnostic NPD. To determine diagnostic NPD frequency, protocols, interpretation, and rater agreement, we surveyed the 18 NPD centres of the European Cystic Fibrosis Society Diagnostic Network Working Group. Fifteen centres reported performing 373 diagnostic NPDs in 2012. Most use the CFF-TDN-SOP (67%) and the chloride-free + isoproterenol response of the side with the largest response (47%) as diagnostic criteria and use centre-specific reference ranges. Rater agreement for five NPD tracings - in general - was good, but poor in tracings with different responses between the two nostrils. NPD is frequently used as a diagnostic and research tool for CF. Performance is highly standardized, centre-specific reference ranges are established, and rater agreement - in general - is good. Centre-independent diagnostic criteria and reference ranges must be defined by multicentre validation studies to improve standardized interpretation for diagnostic use. © 2013.

A Three-Dimensional Receiver Operator Characteristic Surface Diagnostic Metric

NASA Technical Reports Server (NTRS)

Simon, Donald L.

2011-01-01

Receiver Operator Characteristic (ROC) curves are commonly applied as metrics for quantifying the performance of binary fault detection systems. An ROC curve provides a visual representation of a detection system s True Positive Rate versus False Positive Rate sensitivity as the detection threshold is varied. The area under the curve provides a measure of fault detection performance independent of the applied detection threshold. While the standard ROC curve is well suited for quantifying binary fault detection performance, it is not suitable for quantifying the classification performance of multi-fault classification problems. Furthermore, it does not provide a measure of diagnostic latency. To address these shortcomings, a novel three-dimensional receiver operator characteristic (3D ROC) surface metric has been developed. This is done by generating and applying two separate curves: the standard ROC curve reflecting fault detection performance, and a second curve reflecting fault classification performance. A third dimension, diagnostic latency, is added giving rise to 3D ROC surfaces. Applying numerical integration techniques, the volumes under and between the surfaces are calculated to produce metrics of the diagnostic system s detection and classification performance. This paper will describe the 3D ROC surface metric in detail, and present an example of its application for quantifying the performance of aircraft engine gas path diagnostic methods. Metric limitations and potential enhancements are also discussed

Diagnostic sensitivity and specificity of a participatory disease surveillance method for highly pathogenic avian influenza in household chicken flocks in Indonesia.

PubMed

Robyn, M; Priyono, W B; Kim, L M; Brum, E

2012-06-01

A study was conducted to assess the diagnostic sensitivity and specificity of a disease surveillance method for diagnosis of highly pathogenic avian influenza (HPAI) outbreaks in household chicken flocks used by participatory disease surveillance (PDS) teams in Yogyakarta Province, Indonesia. The Government of Indonesia, in partnership with the Food and Agriculture Organization of the United Nations, has implemented a PDS method for the detection of HPAI outbreaks in poultry since 2006. The PDS method in Indonesia utilizes both a clinical case definition (CD) and the result of a commercial rapid antigen test kit Yogyakarta 55611, to diagnose HPAI outbreaks, primarily in backyard chicken flocks. The following diagnostic sensitivities and specificities were obtained relative to real-time reverse transcription-PCR as the gold standard diagnostic test: 1) 89% sensitivity (CI95: 75%-97%) and 96% specificity (CI95: 89%-99%) for the PDS CD alone; 2) 86% sensitivity (CI95: 71%-95%) and 99% specificity (CI95: 94%-100%) for the rapid antigen test alone; and 3) 84% sensitivity (CI95: 68%-94%) and 100% specificity (CI95: 96%-100%) for the PDS CD result combined with the rapid antigen test result. Based on these results, HPAI outbreaks in extensively raised household chickens can be diagnosed with sufficient sensitivity and specificity using the PDS method as implemented in Indonesia. Subject to further field evaluation, data from this study suggest that the diagnostic sensitivity of the PDS method may be improved by expanding the PDS CD to include more possible clinical presentations of HPAI and by increasing the number of rapid antigen tests to three different birds with HPAI-compatible signs of same flock.

Validation of Living Donor Nephrectomy Codes

PubMed Central

Lam, Ngan N.; Lentine, Krista L.; Klarenbach, Scott; Sood, Manish M.; Kuwornu, Paul J.; Naylor, Kyla L.; Knoll, Gregory A.; Kim, S. Joseph; Young, Ann; Garg, Amit X.

2018-01-01

Background: Use of administrative data for outcomes assessment in living kidney donors is increasing given the rarity of complications and challenges with loss to follow-up. Objective: To assess the validity of living donor nephrectomy in health care administrative databases compared with the reference standard of manual chart review. Design: Retrospective cohort study. Setting: 5 major transplant centers in Ontario, Canada. Patients: Living kidney donors between 2003 and 2010. Measurements: Sensitivity and positive predictive value (PPV). Methods: Using administrative databases, we conducted a retrospective study to determine the validity of diagnostic and procedural codes for living donor nephrectomies. The reference standard was living donor nephrectomies identified through the province’s tissue and organ procurement agency, with verification by manual chart review. Operating characteristics (sensitivity and PPV) of various algorithms using diagnostic, procedural, and physician billing codes were calculated. Results: During the study period, there were a total of 1199 living donor nephrectomies. Overall, the best algorithm for identifying living kidney donors was the presence of 1 diagnostic code for kidney donor (ICD-10 Z52.4) and 1 procedural code for kidney procurement/excision (1PC58, 1PC89, 1PC91). Compared with the reference standard, this algorithm had a sensitivity of 97% and a PPV of 90%. The diagnostic and procedural codes performed better than the physician billing codes (sensitivity 60%, PPV 78%). Limitations: The donor chart review and validation study was performed in Ontario and may not be generalizable to other regions. Conclusions: An algorithm consisting of 1 diagnostic and 1 procedural code can be reliably used to conduct health services research that requires the accurate determination of living kidney donors at the population level. PMID:29662679

Bias in logistic regression due to imperfect diagnostic test results and practical correction approaches.

PubMed

Valle, Denis; Lima, Joanna M Tucker; Millar, Justin; Amratia, Punam; Haque, Ubydul

2015-11-04

Logistic regression is a statistical model widely used in cross-sectional and cohort studies to identify and quantify the effects of potential disease risk factors. However, the impact of imperfect tests on adjusted odds ratios (and thus on the identification of risk factors) is under-appreciated. The purpose of this article is to draw attention to the problem associated with modelling imperfect diagnostic tests, and propose simple Bayesian models to adequately address this issue. A systematic literature review was conducted to determine the proportion of malaria studies that appropriately accounted for false-negatives/false-positives in a logistic regression setting. Inference from the standard logistic regression was also compared with that from three proposed Bayesian models using simulations and malaria data from the western Brazilian Amazon. A systematic literature review suggests that malaria epidemiologists are largely unaware of the problem of using logistic regression to model imperfect diagnostic test results. Simulation results reveal that statistical inference can be substantially improved when using the proposed Bayesian models versus the standard logistic regression. Finally, analysis of original malaria data with one of the proposed Bayesian models reveals that microscopy sensitivity is strongly influenced by how long people have lived in the study region, and an important risk factor (i.e., participation in forest extractivism) is identified that would have been missed by standard logistic regression. Given the numerous diagnostic methods employed by malaria researchers and the ubiquitous use of logistic regression to model the results of these diagnostic tests, this paper provides critical guidelines to improve data analysis practice in the presence of misclassification error. Easy-to-use code that can be readily adapted to WinBUGS is provided, enabling straightforward implementation of the proposed Bayesian models.

[Meta-analysis of diagnostic capability of frequency-doubling technology (FDT) for primary glaucoma].

PubMed

Liu, Ting; He, Xiang-ge

2006-05-01

To evaluate the overall diagnostic capabilities of frequency-doubling technology (FDT) in patients of primary glaucoma, with standard automated perimetry (SAP) and/or optic disc appearance as the gold standard. A comprehensive electric search in MEDLINE, EMBASE, Cochrane Library, BIOSIS, Previews, HMIC, IPA, OVID, CNKI, CBMdisc, VIP information, CMCC, CCPD, SSreader and 21dmedia and a manual search in related textbooks, journals, congress articles and their references were performed to identify relevant English and Chinese language articles. Criteria for adaptability were established according to validity criteria for diagnostic research published by the Cochrane Methods Group on Screening and Diagnostic Tests. Quality of the included articles was assessed and relevant materials were extracted for studying. Statistical analysis was performed with Meta Test version 0.6 software. Heterogeneity of the included articles was tested, which was used to select appropriate effect model to calculate pooled weighted sensitivity and specificity. Summary Receiver Operating Characteristic (SROC) curve was established and the area under the curve (AUC) was calculated. Finally, sensitivity analysis was performed. Fifteen English articles (21 studies) of 206 retrieved articles were included in the present study, with a total of 3172 patients. The reported sensitivity of FDT ranged from 0.51 to 1.00, and specificity from 0.58 to 1.00. The pooled weighted sensitivity and specificity for FDT with 95% confidence intervals (95% CI) after correction for standard error were 0.86 (0.80 - 0.90), 0.87 (0.81 - 0.91), respectively. The AUC of SROC was 93.01%. Sensitivity analysis demonstrated no disproportionate influences of individual study. The included articles are of good quality and FDT can be a highly efficient diagnostic test for primary glaucoma based on Meta-analysis. However, a high quality perspective study is still required for further analysis.

Human Vision-Motivated Algorithm Allows Consistent Retinal Vessel Classification Based on Local Color Contrast for Advancing General Diagnostic Exams.

PubMed

Ivanov, Iliya V; Leitritz, Martin A; Norrenberg, Lars A; Völker, Michael; Dynowski, Marek; Ueffing, Marius; Dietter, Johannes

2016-02-01

Abnormalities of blood vessel anatomy, morphology, and ratio can serve as important diagnostic markers for retinal diseases such as AMD or diabetic retinopathy. Large cohort studies demand automated and quantitative image analysis of vascular abnormalities. Therefore, we developed an analytical software tool to enable automated standardized classification of blood vessels supporting clinical reading. A dataset of 61 images was collected from a total of 33 women and 8 men with a median age of 38 years. The pupils were not dilated, and images were taken after dark adaption. In contrast to current methods in which classification is based on vessel profile intensity averages, and similar to human vision, local color contrast was chosen as a discriminator to allow artery vein discrimination and arterial-venous ratio (AVR) calculation without vessel tracking. With 83% ± 1 standard error of the mean for our dataset, we achieved best classification for weighted lightness information from a combination of the red, green, and blue channels. Tested on an independent dataset, our method reached 89% correct classification, which, when benchmarked against conventional ophthalmologic classification, shows significantly improved classification scores. Our study demonstrates that vessel classification based on local color contrast can cope with inter- or intraimage lightness variability and allows consistent AVR calculation. We offer an open-source implementation of this method upon request, which can be integrated into existing tool sets and applied to general diagnostic exams.

Role of liver magnetic resonance imaging in hyperferritinaemia and the diagnosis of iron overload.

PubMed

Ruefer, Axel; Bapst, Christine; Benz, Rudolf; Bremerich, Jens; Cantoni, Nathan; Infanti, Laura; Samii, Kaveh; Schmid, Mathias; Vallée, Jean-Paul

2017-11-09

Hyperferritinaemia is a frequent clinical problem. Elevated serum ferritin levels can be detected in different genetic and acquired diseases and can occur with or without anaemia. It is therefore important to determine whether hyperferritinaemia is due to iron overload or due to a secondary cause. The main causes of iron overload are intestinal iron hyperabsorption disorders and transfusion-dependent disorders. Iron homeostasis and iron overload are quantified by different diagnostic approaches. The evaluation of serum ferritin and transferrin saturation is the first diagnostic step to identify the cause of hyperferritinaemia. The assessment of liver iron concentration by liver biopsy or magnetic resonance imaging (MRI) may guide the further diagnostic and therapeutic workup. Liver biopsy is invasive and poorly accepted by patients and should only be carried out in selected patients with hereditary haemochromatosis. As a non-invasive approach, MRI is considered the standard method to diagnose and to monitor both hepatic iron overload and the effectiveness of iron chelation therapy in many clinical conditions such as thalassaemia and myelodysplastic syndromes. Accurate evaluation and monitoring of iron overload has major implications regarding adherence, quality of life and prognosis. There are different technical MRI approaches to measuring the liver iron content. Of these, T2 and T2* relaxometry are considered the standard of care. MRI with cardiac T2* mapping is also suitable for the assessment of cardiac iron. Currently there is no consensus which technique should be preferred. The choice depends on local availability and patient population. However, it is important to use the same MRI technique in subsequent visits in the same patient to get comparable results. Signal intensity ratio may be a good adjunct to R2 and R2* methods as it allows easy visual estimation of the liver iron concentration. In this review a group of Swiss haematologists and radiologists give an overview of different conditions leading to primary or secondary iron overload and on diagnostic methods to assess hyperferritinaemia with a focus on the role of liver MRI. They summarise the standard practice in Switzerland on the use of liver iron concentration MRI as well as disease-specific guideline recommendations.

Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients.

PubMed

Le Faivre, Julien; Duhamel, Alain; Khung, Suonita; Faivre, Jean-Baptiste; Lamblin, Nicolas; Remy, Jacques; Remy-Jardin, Martine

2016-11-01

To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. • Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

BRIEF REPORT: Beyond Clinical Experience: Features of Data Collection and Interpretation That Contribute to Diagnostic Accuracy

PubMed Central

Nendaz, Mathieu R; Gut, Anne M; Perrier, Arnaud; Louis-Simonet, Martine; Blondon-Choa, Katherine; Herrmann, François R; Junod, Alain F; Vu, Nu V

2006-01-01

BACKGROUND Clinical experience, features of data collection process, or both, affect diagnostic accuracy, but their respective role is unclear. OBJECTIVE, DESIGN Prospective, observational study, to determine the respective contribution of clinical experience and data collection features to diagnostic accuracy. METHODS Six Internists, 6 second year internal medicine residents, and 6 senior medical students worked up the same 7 cases with a standardized patient. Each encounter was audiotaped and immediately assessed by the subjects who indicated the reasons underlying their data collection. We analyzed the encounters according to diagnostic accuracy, information collected, organ systems explored, diagnoses evaluated, and final decisions made, and we determined predictors of diagnostic accuracy by logistic regression models. RESULTS Several features significantly predicted diagnostic accuracy after correction for clinical experience: early exploration of correct diagnosis (odds ratio [OR] 24.35) or of relevant diagnostic hypotheses (OR 2.22) to frame clinical data collection, larger number of diagnostic hypotheses evaluated (OR 1.08), and collection of relevant clinical data (OR 1.19). CONCLUSION Some features of data collection and interpretation are related to diagnostic accuracy beyond clinical experience and should be explicitly included in clinical training and modeled by clinical teachers. Thoroughness in data collection should not be considered a privileged way to diagnostic success. PMID:17105525

PubMed Central

Schulz-Wendtland, Rüdiger; Jud, Sebastian M.; Fasching, Peter A.; Hartmann, Arndt; Radicke, Marcus; Rauh, Claudia; Uder, Michael; Wunderle, Marius; Gass, Paul; Langemann, Hanna; Beckmann, Matthias W.; Emons, Julius

2017-01-01

Aim The combination of different imaging modalities through the use of fusion devices promises significant diagnostic improvement for breast pathology. The aim of this study was to evaluate image quality and clinical feasibility of a prototype fusion device (fusion prototype) constructed from a standard tomosynthesis mammography unit and a standard 3D ultrasound probe using a new method of breast compression. Materials and Methods Imaging was performed on 5 mastectomy specimens from patients with confirmed DCIS or invasive carcinoma (BI-RADS ™ 6). For the preclinical fusion prototype an ABVS system ultrasound probe from an Acuson S2000 was integrated into a MAMMOMAT Inspiration (both Siemens Healthcare Ltd) and, with the aid of a newly developed compression plate, digital mammogram and automated 3D ultrasound images were obtained. Results The quality of digital mammogram images produced by the fusion prototype was comparable to those produced using conventional compression. The newly developed compression plate did not influence the applied x-ray dose. The method was not more labour intensive or time-consuming than conventional mammography. From the technical perspective, fusion of the two modalities was achievable. Conclusion In this study, using only a few mastectomy specimens, the fusion of an automated 3D ultrasound machine with a standard mammography unit delivered images of comparable quality to conventional mammography. The device allows simultaneous ultrasound – the second important imaging modality in complementary breast diagnostics – without increasing examination time or requiring additional staff. PMID:28713173

Aetiology of Intellectual Disability in Paediatric Outpatients in Northern India

ERIC Educational Resources Information Center

Jauhari, Prashant; Boggula, Raju; Bhave, Anupama; Bhargava, Roli; Singh, Chandrakanta; Kohli, Neera; Yadav, Rajesh; Kumar, Rashmi

2011-01-01

Aim: To study the aetiology of intellectual disability in patients presenting to hospital and the diagnostic yield of a standardized examination. Method: Over a 1-year period, the first three children presenting to the paediatric outpatients department (OPD) on 2 selected weekdays with developmental delay, suspected intellectual disability, or…

Strategies for Teaching Fractions: Using Error Analysis for Intervention and Assessment

ERIC Educational Resources Information Center

Spangler, David B.

2011-01-01

Many students struggle with fractions and must understand them before learning higher-level math. Veteran educator David B. Spangler provides research-based tools that are aligned with NCTM and Common Core State Standards. He outlines powerful diagnostic methods for analyzing student work and providing timely, specific, and meaningful…

What Is So Special about Special Education?

ERIC Educational Resources Information Center

Dettermann, Douglas K.; Thompson, Lee Anne

1997-01-01

Special educational methods need to develop beyond the diagnostic use of IQ tests. Individual differences in cognitive abilities of students need to be understood and need to be incorporated into effective individualized educational interventions. The goal is to raise the level of performance and the standard deviation of performance. (MMU)

Diagnostic accuracy of a volume-rendered computed tomography movie and other computed tomography-based imaging methods in assessment of renal vascular anatomy for laparoscopic donor nephrectomy.

PubMed

Yamamoto, Shingo; Tanooka, Masao; Ando, Kumiko; Yamano, Toshiko; Ishikura, Reiichi; Nojima, Michio; Hirota, Shozo; Shima, Hiroki

2009-12-01

To evaluate the diagnostic accuracy of computed tomography (CT)-based imaging methods for assessing renal vascular anatomy, imaging studies, including standard axial CT, three-dimensional volume-rendered CT (3DVR-CT), and a 3DVR-CT movie, were performed on 30 patients who underwent laparoscopic donor nephrectomy (10 right side, 20 left side) for predicting the location of the renal arteries and renal, adrenal, gonadal, and lumbar veins. These findings were compared with videos obtained during the operation. Two of 37 renal arteries observed intraoperatively were missed by standard axial CT and 3DVR-CT, whereas all arteries were identified by the 3DVR-CT movie. Two of 36 renal veins were missed by standard axial CT and 3DVR-CT, whereas 1 was missed by the 3DVR-CT movie. In 20 left renal hilar anatomical structures, 20 adrenal, 20 gonadal, and 22 lumbar veins were observed during the operation. Preoperatively, the standard axial CT, 3DVR-CT, and 3DVR-CT movie detected 11, 19, and 20 adrenal veins; 13, 14, and 19 gonadal veins; and 6, 11, and 15 lumbar veins, respectively. Overall, of 135 renal vascular structures, the standard axial CT, 3DVR-CT, and 3DVR-CT movie accurately detected 99 (73.3%), 113 (83.7%), and 126 (93.3%) vessels, respectively, which indicated that the 3DVR-CT movie demonstrated a significantly higher detection rate than other CT-based imaging methods (P < 0.05). The 3DVR-CT movie accurately provides essential information about the renal vascular anatomy before laparoscopic donor nephrectomy.

Developing standards for malaria microscopy: external competency assessment for malaria microscopists in the Asia-Pacific

PubMed Central

2012-01-01

Background Malaria diagnosis has received renewed interest in recent years, associated with the increasing accessibility of accurate diagnosis through the introduction of rapid diagnostic tests and new World Health Organization guidelines recommending parasite-based diagnosis prior to anti-malarial therapy. However, light microscopy, established over 100 years ago and frequently considered the reference standard for clinical diagnosis, has been neglected in control programmes and in the malaria literature and evidence suggests field standards are commonly poor. Microscopy remains the most accessible method for parasite quantitation, for drug efficacy monitoring, and as a reference of assessing other diagnostic tools. This mismatch between quality and need highlights the importance of the establishment of reliable standards and procedures for assessing and assuring quality. This paper describes the development, function and impact of a multi-country microscopy external quality assurance network set up for this purpose in Asia. Methods Surveys were used for key informants and past participants for feedback on the quality assurance programme. Competency scores for each country from 14 participating countries were compiled for analyses using paired sample t-tests. In-depth interviews were conducted with key informants including the programme facilitators and national level microscopists. Results External assessments and limited retraining through a formalized programme based on a reference slide bank has demonstrated an increase in standards of competence of senior microscopists over a relatively short period of time, at a potentially sustainable cost. The network involved in the programme now exceeds 14 countries in the Asia-Pacific, and the methods are extended to other regions. Conclusions While the impact on national programmes varies, it has translated in some instances into a strengthening of national microscopy standards and offers a possibility both for supporting revival of national microcopy programmes, and for the development of globally recognized standards of competency needed both for patient management and field research. PMID:23095668

Laboratory diagnosis of Ebola virus disease and corresponding biosafety considerations in the China Ebola Treatment Center.

PubMed

Huang, Qing; Fu, Wei-Ling; You, Jian-Ping; Mao, Qing

2016-10-01

Ebola virus disease (EVD), caused by Ebola virus (EBOV), is a potent acute infectious disease with a high case-fatality rate. Etiological and serological EBOV detection methods, including techniques that involve the detection of the viral genome, virus-specific antigens and anti-virus antibodies, are standard laboratory diagnostic tests that facilitate confirmation or exclusion of EBOV infection. In addition, routine blood tests, liver and kidney function tests, electrolytes and coagulation tests and other diagnostic examinations are important for the clinical diagnosis and treatment of EVD. Because of the viral load in body fluids and secretions from EVD patients, all body fluids are highly contagious. As a result, biosafety control measures during the collection, transport and testing of clinical specimens obtained from individuals scheduled to undergo EBOV infection testing (including suspected, probable and confirmed cases) are crucial. This report has been generated following extensive work experience in the China Ebola Treatment Center (ETC) in Liberia and incorporates important information pertaining to relevant diagnostic standards, clinical significance, operational procedures, safety controls and other issues related to laboratory testing of EVD. Relevant opinions and suggestions are presented in this report to provide contextual awareness associated with the development of standards and/or guidelines related to EVD laboratory testing.

Airside HVAC BESTEST. Adaptation of ASHRAE RP 865 Airside HVAC Equipment Modeling Test Cases for ASHRAE Standard 140. Volume 1, Cases AE101-AE445

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neymark, J.; Kennedy, M.; Judkoff, R.

This report documents a set of diagnostic analytical verification cases for testing the ability of whole building simulation software to model the air distribution side of typical heating, ventilating and air conditioning (HVAC) equipment. These cases complement the unitary equipment cases included in American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 140, Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs, which test the ability to model the heat-transfer fluid side of HVAC equipment.

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature.

PubMed

Tang, Weiming; Chen, Wen; Amini, Ali; Boeras, Debi; Falconer, Jane; Kelly, Helen; Peeling, Rosanna; Varsaneux, Olivia; Tucker, Joseph D; Easterbrook, Philippa

2017-11-01

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV. We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3. A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%). RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.

Rapid and effective processing of blood specimens for diagnostic PCR using filter paper and Chelex-100.

PubMed

Polski, J M; Kimzey, S; Percival, R W; Grosso, L E

1998-08-01

To provide a more efficient method for isolating DNA from peripheral blood for use in diagnostic DNA mutation analysis. The use of blood impregnated filter paper and Chelex-100 in DNA isolation was evaluated and compared with standard DNA isolation techniques. In polymerase chain reaction (PCR) based assays of five point mutations, identical results were obtained with DNA isolated routinely from peripheral blood and isolated using the filter paper and Chelex-100 method. In the clinical setting, this method provides a useful alternative to conventional DNA isolation. It is easily implemented and inexpensive, and provides sufficient, stable DNA for multiple assays. The potential for specimen contamination is reduced because most of the steps are performed in a single microcentrifuge tube. In addition, this method provides for easy storage and transport of samples from the point of acquisition.

Real-time teleophthalmology versus face-to-face consultation: A systematic review.

PubMed

Tan, Irene J; Dobson, Lucy P; Bartnik, Stephen; Muir, Josephine; Turner, Angus W

2017-08-01

Introduction Advances in imaging capabilities and the evolution of real-time teleophthalmology have the potential to provide increased coverage to areas with limited ophthalmology services. However, there is limited research assessing the diagnostic accuracy of face-to-face teleophthalmology consultation. This systematic review aims to determine if real-time teleophthalmology provides comparable accuracy to face-to-face consultation for the diagnosis of common eye health conditions. Methods A search of PubMed, Embase, Medline and Cochrane databases and manual citation review was conducted on 6 February and 7 April 2016. Included studies involved real-time telemedicine in the field of ophthalmology or optometry, and assessed diagnostic accuracy against gold-standard face-to-face consultation. The revised quality assessment of diagnostic accuracy studies (QUADAS-2) tool assessed risk of bias. Results Twelve studies were included, with participants ranging from four to 89 years old. A broad number of conditions were assessed and include corneal and retinal pathologies, strabismus, oculoplastics and post-operative review. Quality assessment identified a high or unclear risk of bias in patient selection (75%) due to an undisclosed recruitment processes. The index test showed high risk of bias in the included studies, due to the varied interpretation and conduct of real-time teleophthalmology methods. Reference standard risk was overall low (75%), as was the risk due to flow and timing (75%). Conclusion In terms of diagnostic accuracy, real-time teleophthalmology was considered superior to face-to-face consultation in one study and comparable in six studies. Store-and-forward image transmission coupled with real-time videoconferencing is a suitable alternative to overcome poor internet transmission speeds.

Tuberculosis management practices by private practitioners in Andhra Pradesh, India.

PubMed

Achanta, Shanta; Jaju, Jyoti; Kumar, Ajay M V; Nagaraja, Sharath Burugina; Shamrao, Srinivas Rao Motta; Bandi, Sasidhar Kumar; Kumar, Ashok; Satyanarayana, Srinath; Harries, Anthony David; Nair, Sreenivas Achutan; Dewan, Puneet K

2013-01-01

Private medical practitioners in Visakhapatnam district, Andhra Pradesh, India. To evaluate self-reported TB diagnostic and treatment practices amongst private medical practitioners against benchmark practices articulated in the International Standards of Tuberculosis Care (ISTC), and factors associated with compliance with ISTC. Cross- sectional survey using semi-structured interviews. Of 296 randomly selected private practitioners, 201 (68%) were assessed for compliance to ISTC diagnostic and treatment standards in TB management. Only 11 (6%) followed a combination of 6 diagnostic standards together and only 1 followed a combination of all seven treatment standards together. There were 28 (14%) private practitioners who complied with a combination of three core ISTC (cough for tuberculosis suspects, sputum smear examination and use of standardized treatment). Higher ISTC compliance was associated with caring for more than 20 TB patients annually, prior sensitization to TB control guidelines, and practice of alternate systems of medicine. Few private practitioners in Visakhapatnam, India reported TB diagnostic and treatment practices that met ISTC. Better engagement of the private sector is urgently required to improve TB management practices and to prevent diagnostic delay and drug resistance.

The Autism Diagnostic Observation Schedule--Toddler Module: A New Module of a Standardized Diagnostic Measure for Autism Spectrum Disorders

ERIC Educational Resources Information Center

Luyster, Rhiannon; Gotham, Katherine; Guthrie, Whitney; Coffing, Mia; Petrak, Rachel; Pierce, Karen; Bishop, Somer; Esler, Amy; Hus, Vanessa; Oti, Rosalind; Richler, Jennifer; Risi, Susan; Lord, Catherine

2009-01-01

The Autism Diagnostic Observation Schedule (ADOS; Lord et al., J Autism Dev Disord, 30(3):205-223, 2000) is widely accepted as a "gold standard" diagnostic instrument, but it is of restricted utility with very young children. The purpose of the current project was to modify the ADOS for use in children under 30 months of age. A modified ADOS, the…

Towards a Standard Psychometric Diagnostic Interview for Subjects at Ultra High Risk of Psychosis: CAARMS versus SIPS

PubMed Central

Fusar-Poli, P.; Cappucciati, M.; Rutigliano, G.; Lee, T. Y.; Beverly, Q.; Bonoldi, I.; Lelli, J.; Kaar, S. J.; Gago, E.; Rocchetti, M.; Patel, R.; Bhavsar, V.; Tognin, S.; Badger, S.; Calem, M.; Lim, K.; Kwon, J. S.; Perez, J.; McGuire, P.

2016-01-01

Background. Several psychometric instruments are available for the diagnostic interview of subjects at ultra high risk (UHR) of psychosis. Their diagnostic comparability is unknown. Methods. All referrals to the OASIS (London) or CAMEO (Cambridgeshire) UHR services from May 13 to Dec 14 were interviewed for a UHR state using both the CAARMS 12/2006 and the SIPS 5.0. Percent overall agreement, kappa, the McNemar-Bowker χ 2 test, equipercentile methods, and residual analyses were used to investigate diagnostic outcomes and symptoms severity or frequency. A conversion algorithm (CONVERT) was validated in an independent UHR sample from the Seoul Youth Clinic (Seoul). Results. There was overall substantial CAARMS-versus-SIPS agreement in the identification of UHR subjects (n = 212, percent overall agreement = 86%; kappa = 0.781, 95% CI from 0.684 to 0.878; McNemar-Bowker test = 0.069), with the exception of the brief limited intermittent psychotic symptoms (BLIPS) subgroup. Equipercentile-linking table linked symptoms severity and frequency across the CAARMS and SIPS. The conversion algorithm was validated in 93 UHR subjects, showing excellent diagnostic accuracy (CAARMS to SIPS: ROC area 0.929; SIPS to CAARMS: ROC area 0.903). Conclusions. This study provides initial comparability data between CAARMS and SIPS and will inform ongoing multicentre studies and clinical guidelines for the UHR psychometric diagnostic interview. PMID:27314005

Evaluating concentration estimation errors in ELISA microarray experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daly, Don S.; White, Amanda M.; Varnum, Susan M.

Enzyme-linked immunosorbent assay (ELISA) is a standard immunoassay to predict a protein concentration in a sample. Deploying ELISA in a microarray format permits simultaneous prediction of the concentrations of numerous proteins in a small sample. These predictions, however, are uncertain due to processing error and biological variability. Evaluating prediction error is critical to interpreting biological significance and improving the ELISA microarray process. Evaluating prediction error must be automated to realize a reliable high-throughput ELISA microarray system. Methods: In this paper, we present a statistical method based on propagation of error to evaluate prediction errors in the ELISA microarray process. Althoughmore » propagation of error is central to this method, it is effective only when comparable data are available. Therefore, we briefly discuss the roles of experimental design, data screening, normalization and statistical diagnostics when evaluating ELISA microarray prediction errors. We use an ELISA microarray investigation of breast cancer biomarkers to illustrate the evaluation of prediction errors. The illustration begins with a description of the design and resulting data, followed by a brief discussion of data screening and normalization. In our illustration, we fit a standard curve to the screened and normalized data, review the modeling diagnostics, and apply propagation of error.« less

[Pilot tests using molecular diagnostic assay cervicovaginal infection during pregnancy].

PubMed

Beltrán-Montoya, J; Escudero-Gontes, S; Martínez-Huerta, N E; Ávila-Vergara, M A; Morales-Hernández, V; Canchola-Sotelo, C; Palacios-González, B; Vadillo-Ortega, F

2016-08-01

The prevalence of cervicovaginal infections during pregnancy has been associated with adverse perinatal outcomes however, the actual approach used for diagnosis is not effective. The aim of this study was to compare the diagnosis of vaginal infections in pregnant women using clinical, molecular diagnostic and traditional microbiological culture in a pilot study, to determine the prevalence and association with the development of preterm labor. We performed a nested cross-sectional study composed by 54 women in a cohort of pregnant women in Mexico City. Cervicovaginal infections were evaluated by clinical methods, microbiology culture and a commercially available molecular biology test. Prevalence of cervicovaginal infections during pregnancy was estimated between 28% and 50% according to methodologies. Considering the clinical diagnosis of preterm labor as the gold standard, all diagnostic tests were poor as predictors of preterm labor. Traditional approaches to establish the significance of cervicovaginal infection in pregnancy are exhausted, so be sought new ways to understand this complex relationship. Meanwhile it is recommended to continue to use traditional methods to identify infections during pregnancy in both knowledge of new methods aimed at understanding these relationships are sophisticated.

Comparison of tissue equalization, and premium view post-processing methods in full field digital mammography.

PubMed

Chen, Baoying; Wang, Wei; Huang, Jin; Zhao, Ming; Cui, Guangbin; Xu, Jing; Guo, Wei; Du, Pang; Li, Pei; Yu, Jun

2010-10-01

To retrospectively evaluate the diagnostic abilities of 2 post-processing methods provided by GE Senographe DS system, tissue equalization (TE) and premium view (PV) in full field digital mammography (FFDM). In accordance with the ethical standards of the World Medical Association, this study was approved by regional ethics committee and signed informed patient consents were obtained. We retrospectively reviewed digital mammograms from 101 women (mean age, 47 years; range, 23-81 years) in the modes of TE and PV, respectively. Three radiologists, fully blinded to the post-processing methods, all patient clinical information and histologic results, read images by using objective image interpretation criteria for diagnostic information end points such as lesion border delineation, definition of disease extent, visualization of internal and surrounding morphologic features of the lesions. Also, overall diagnostic impression in terms of lesion conspicuity, detectability and diagnostic confidence was assessed. Between-group comparisons were performed with Wilcoxon signed rank test. Readers 1, 2, and 3 demonstrated significant overall better impression of PV in 29, 27, and 24 patients, compared with that for TE in 12, 13, and 11 patients, respectively (p<0.05). Significant (p<0.05) better impression of PV was also demonstrated for diagnostic information end points. Importantly, PV proved to be more sensitive than TE while detecting malignant lesions in dense breast rather than benign lesions and malignancy in non-dense breast (p<0.01). PV compared with TE provides marked better diagnostic information in FFDM, particularly for patients with malignancy in dense breast. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Simplified method for creating a density-absorbed dose calibration curve for the low dose range from Gafchromic EBT3 film.

PubMed

Gotanda, Tatsuhiro; Katsuda, Toshizo; Gotanda, Rumi; Kuwano, Tadao; Akagawa, Takuya; Tanki, Nobuyoshi; Tabuchi, Akihiko; Shimono, Tetsunori; Kawaji, Yasuyuki

2016-01-01

Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber in that the dosimetry process is time-consuming for creating a density-absorbed dose calibration curve. The purpose of this study was the development of a simplified method of creating a density-absorbed dose calibration curve from radiochromic film within a short time. This simplified method was performed using Gafchromic EBT3 film with a low energy dependence and step-shaped Al filter. The simplified method was compared with the standard method. The density-absorbed dose calibration curves created using the simplified and standard methods exhibited approximately similar straight lines, and the gradients of the density-absorbed dose calibration curves were -32.336 and -33.746, respectively. The simplified method can obtain calibration curves within a much shorter time compared to the standard method. It is considered that the simplified method for EBT3 film offers a more time-efficient means of determining the density-absorbed dose calibration curve within a low absorbed dose range such as the diagnostic range.

Simplified method for creating a density-absorbed dose calibration curve for the low dose range from Gafchromic EBT3 film

PubMed Central

Gotanda, Tatsuhiro; Katsuda, Toshizo; Gotanda, Rumi; Kuwano, Tadao; Akagawa, Takuya; Tanki, Nobuyoshi; Tabuchi, Akihiko; Shimono, Tetsunori; Kawaji, Yasuyuki

2016-01-01

Radiochromic film dosimeters have a disadvantage in comparison with an ionization chamber in that the dosimetry process is time-consuming for creating a density-absorbed dose calibration curve. The purpose of this study was the development of a simplified method of creating a density-absorbed dose calibration curve from radiochromic film within a short time. This simplified method was performed using Gafchromic EBT3 film with a low energy dependence and step-shaped Al filter. The simplified method was compared with the standard method. The density-absorbed dose calibration curves created using the simplified and standard methods exhibited approximately similar straight lines, and the gradients of the density-absorbed dose calibration curves were −32.336 and −33.746, respectively. The simplified method can obtain calibration curves within a much shorter time compared to the standard method. It is considered that the simplified method for EBT3 film offers a more time-efficient means of determining the density-absorbed dose calibration curve within a low absorbed dose range such as the diagnostic range. PMID:28144120

Invasive candidiasis: future directions in non-culture based diagnosis.

PubMed

Posch, Wilfried; Heimdörfer, David; Wilflingseder, Doris; Lass-Flörl, Cornelia

2017-09-01

Delayed initial antifungal therapy is associated with high mortality rates caused by invasive candida infections, since accurate detection of the opportunistic pathogenic yeast and its identification display a diagnostic challenge. diagnosis of candida infections relies on time-consuming methods such as blood cultures, serologic and histopathologic examination. to allow for fast detection and characterization of invasive candidiasis, there is a need to improve diagnostic tools. trends in diagnostics switch to non-culture-based methods, which allow specified diagnosis within significantly shorter periods of time in order to provide early and appropriate antifungal treatment. Areas covered: within this review comprise novel pathogen- and host-related testing methods, e.g. multiplex-PCR analyses, T2 magnetic resonance, fungus-specific DNA microarrays, microRNA characterization or analyses of IL-17 as biomarker for early detection of invasive candidiasis. Expert commentary: Early recognition and diagnosis of fungal infections is a key issue for improved patient management. As shown in this review, a broad range of novel molecular based tests for the detection and identification of Candida species is available. However, several assays are in-house assays and lack standardization, clinical validation as well as data on sensitivity and specificity. This underscores the need for the development of faster and more accurate diagnostic tests.

Feasibility assessment of yttrium-90 liver radioembolization imaging using amplitude-based gated PET/CT

PubMed Central

Acuff, Shelley N.; Neveu, Melissa L.; Syed, Mumtaz; Kaman, Austin D.; Fu, Yitong

2018-01-01

Purpose The usage of PET/computed tomography (CT) to monitor hepatocellular carcinoma patients following yttrium-90 (90Y) radioembolization has increased. Respiratory motion causes liver movement, which can be corrected using gating techniques at the expense of added noise. This work examines the use of amplitude-based gating on 90Y-PET/CT and its potential impact on diagnostic integrity. Patients and methods Patients were imaged using PET/CT following 90Y radioembolization. A respiratory band was used to collect respiratory cycle data. Patient data were processed as both standard and motion-corrected images. Regions of interest were drawn and compared using three methods. Activity concentrations were calculated and converted into dose estimates using previously determined and published scaling factors. Diagnostic assessments were performed using a binary scale created from published 90Y-PET/CT image interpretation guidelines. Results Estimates of radiation dose were increased (P<0.05) when using amplitude-gating methods with 90Y PET/CT imaging. Motion-corrected images show increased noise, but the diagnostic determination of success, using the Kao criteria, did not change between static and motion-corrected data. Conclusion Amplitude-gated PET/CT following 90Y radioembolization is feasible and may improve 90Y dose estimates while maintaining diagnostic assessment integrity. PMID:29351124

Computational diagnosis of canine lymphoma

NASA Astrophysics Data System (ADS)

Mirkes, E. M.; Alexandrakis, I.; Slater, K.; Tuli, R.; Gorban, A. N.

2014-03-01

One out of four dogs will develop cancer in their lifetime and 20% of those will be lymphoma cases. PetScreen developed a lymphoma blood test using serum samples collected from several veterinary practices. The samples were fractionated and analysed by mass spectrometry. Two protein peaks, with the highest diagnostic power, were selected and further identified as acute phase proteins, C-Reactive Protein and Haptoglobin. Data mining methods were then applied to the collected data for the development of an online computer-assisted veterinary diagnostic tool. The generated software can be used as a diagnostic, monitoring and screening tool. Initially, the diagnosis of lymphoma was formulated as a classification problem and then later refined as a lymphoma risk estimation. Three methods, decision trees, kNN and probability density evaluation, were used for classification and risk estimation and several preprocessing approaches were implemented to create the diagnostic system. For the differential diagnosis the best solution gave a sensitivity and specificity of 83.5% and 77%, respectively (using three input features, CRP, Haptoglobin and standard clinical symptom). For the screening task, the decision tree method provided the best result, with sensitivity and specificity of 81.4% and >99%, respectively (using the same input features). Furthermore, the development and application of new techniques for the generation of risk maps allowed their user-friendly visualization.

DIAGNOSTIC ACCURACY OF PHYSICAL EXAMINATION TESTS OF THE ANKLE/FOOT COMPLEX: A SYSTEMATIC REVIEW

PubMed Central

Schwieterman, Braun; Haas, Deniele; Columber, Kirby; Knupp, Darren

2013-01-01

Background: Orthopedic special tests of the ankle/foot complex are routinely used during the physical examination process in order to help diagnose ankle/lower leg pathologies. Purpose: The purpose of this systematic review was to investigate the diagnostic accuracy of ankle/lower leg special tests. Methods: A search of the current literature was conducted using PubMed, CINAHL, SPORTDiscus, ProQuest Nursing and Allied Health Sources, Scopus, and Cochrane Library. Studies were eligible if they included the following: 1) a diagnostic clinical test of musculoskeletal pathology in the ankle/foot complex, 2) description of the clinical test or tests, 3) a report of the diagnostic accuracy of the clinical test (e.g. sensitivity and specificity), and 4) an acceptable reference standard for comparison. The quality of included studies was determined by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Results: Nine diagnostic accuracy studies met the inclusion criteria for this systematic review; analyzing a total of 16 special tests of the ankle/foot complex. After assessment using the QUADAS-2, only one study had low risk of bias and low concerns regarding applicability. Conclusion: Most ankle/lower leg orthopedic special tests are confirmatory in nature and are best utilized at the end of the physical examination. Most of the studies included in this systematic review demonstrate notable biases, which suggest that results and recommendations in this review should be taken as a guide rather than an outright standard. There is need for future research with more stringent study design criteria so that more accurate diagnostic power of ankle/lower leg special tests can be determined. Level of Evidence: 3a PMID:24175128

European Respiratory Society guidelines for the diagnosis of primary ciliary dyskinesia.

PubMed

Lucas, Jane S; Barbato, Angelo; Collins, Samuel A; Goutaki, Myrofora; Behan, Laura; Caudri, Daan; Dell, Sharon; Eber, Ernst; Escudier, Estelle; Hirst, Robert A; Hogg, Claire; Jorissen, Mark; Latzin, Philipp; Legendre, Marie; Leigh, Margaret W; Midulla, Fabio; Nielsen, Kim G; Omran, Heymut; Papon, Jean-Francois; Pohunek, Petr; Redfern, Beatrice; Rigau, David; Rindlisbacher, Bernhard; Santamaria, Francesca; Shoemark, Amelia; Snijders, Deborah; Tonia, Thomy; Titieni, Andrea; Walker, Woolf T; Werner, Claudius; Bush, Andrew; Kuehni, Claudia E

2017-01-01

The diagnosis of primary ciliary dyskinesia is often confirmed with standard, albeit complex and expensive, tests. In many cases, however, the diagnosis remains difficult despite the array of sophisticated diagnostic tests. There is no "gold standard" reference test. Hence, a Task Force supported by the European Respiratory Society has developed this guideline to provide evidence-based recommendations on diagnostic testing, especially in light of new developments in such tests, and the need for robust diagnoses of patients who might enter randomised controlled trials of treatments. The guideline is based on pre-defined questions relevant for clinical care, a systematic review of the literature, and assessment of the evidence using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. It focuses on clinical presentation, nasal nitric oxide, analysis of ciliary beat frequency and pattern by high-speed video-microscopy analysis, transmission electron microscopy, genotyping and immunofluorescence. It then used a modified Delphi survey to develop an algorithm for the use of diagnostic tests to definitively confirm and exclude the diagnosis of primary ciliary dyskinesia; and to provide advice when the diagnosis was not conclusive. Finally, this guideline proposes a set of quality criteria for future research on the validity of diagnostic methods for primary ciliary dyskinesia. Copyright ©ERS 2017.

A general diagnostic model applied to language testing data.

PubMed

von Davier, Matthias

2008-11-01

Probabilistic models with one or more latent variables are designed to report on a corresponding number of skills or cognitive attributes. Multidimensional skill profiles offer additional information beyond what a single test score can provide, if the reported skills can be identified and distinguished reliably. Many recent approaches to skill profile models are limited to dichotomous data and have made use of computationally intensive estimation methods such as Markov chain Monte Carlo, since standard maximum likelihood (ML) estimation techniques were deemed infeasible. This paper presents a general diagnostic model (GDM) that can be estimated with standard ML techniques and applies to polytomous response variables as well as to skills with two or more proficiency levels. The paper uses one member of a larger class of diagnostic models, a compensatory diagnostic model for dichotomous and partial credit data. Many well-known models, such as univariate and multivariate versions of the Rasch model and the two-parameter logistic item response theory model, the generalized partial credit model, as well as a variety of skill profile models, are special cases of this GDM. In addition to an introduction to this model, the paper presents a parameter recovery study using simulated data and an application to real data from the field test for TOEFL Internet-based testing.

Standard CMMI Appraisal Method for Process Improvement (SCAMPI) A, Version 1.3: Method Definition Document

DTIC Science & Technology

2011-03-01

performance of Federal Government Contract Number FA8721-05- C -0003 with Carnegie Mellon University for the operation of the Software Engineering... C Roles and Responsibilities 195 Appendix D Reporting Requirements and Options 201 Appendix E Managed Discovery 203 Appendix F Scoping and...Upgrade Team (SUT) • Mary Busby , Lockheed Martin • Palma Buttles-Valdez, Software Engineering Institute • Paul Byrnes, Integrated System Diagnostics

Sample size in studies on diagnostic accuracy in ophthalmology: a literature survey.

PubMed

Bochmann, Frank; Johnson, Zoe; Azuara-Blanco, Augusto

2007-07-01

To assess the sample sizes used in studies on diagnostic accuracy in ophthalmology. Design and sources: A survey literature published in 2005. The frequency of reporting calculations of sample sizes and the samples' sizes were extracted from the published literature. A manual search of five leading clinical journals in ophthalmology with the highest impact (Investigative Ophthalmology and Visual Science, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology and British Journal of Ophthalmology) was conducted by two independent investigators. A total of 1698 articles were identified, of which 40 studies were on diagnostic accuracy. One study reported that sample size was calculated before initiating the study. Another study reported consideration of sample size without calculation. The mean (SD) sample size of all diagnostic studies was 172.6 (218.9). The median prevalence of the target condition was 50.5%. Only a few studies consider sample size in their methods. Inadequate sample sizes in diagnostic accuracy studies may result in misleading estimates of test accuracy. An improvement over the current standards on the design and reporting of diagnostic studies is warranted.

Spatial enhancement of ECG using diagnostic similarity score based lead selective multi-scale linear model.

PubMed

Nallikuzhy, Jiss J; Dandapat, S

2017-06-01

In this work, a new patient-specific approach to enhance the spatial resolution of ECG is proposed and evaluated. The proposed model transforms a three-lead ECG into a standard twelve-lead ECG thereby enhancing its spatial resolution. The three leads used for prediction are obtained from the standard twelve-lead ECG. The proposed model takes advantage of the improved inter-lead correlation in wavelet domain. Since the model is patient-specific, it also selects the optimal predictor leads for a given patient using a lead selection algorithm. The lead selection algorithm is based on a new diagnostic similarity score which computes the diagnostic closeness between the original and the spatially enhanced leads. Standard closeness measures are used to assess the performance of the model. The similarity in diagnostic information between the original and the spatially enhanced leads are evaluated using various diagnostic measures. Repeatability and diagnosability are performed to quantify the applicability of the model. A comparison of the proposed model is performed with existing models that transform a subset of standard twelve-lead ECG into the standard twelve-lead ECG. From the analysis of the results, it is evident that the proposed model preserves diagnostic information better compared to other models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultrasound for Distal Forearm Fracture: A Systematic Review and Diagnostic Meta-Analysis

PubMed Central

Douma-den Hamer, Djoke; Blanker, Marco H.; Edens, Mireille A.; Buijteweg, Lonneke N.; Boomsma, Martijn F.; van Helden, Sven H.; Mauritz, Gert-Jan

2016-01-01

Study Objective To determine the diagnostic accuracy of ultrasound for detecting distal forearm fractures. Methods A systematic review and diagnostic meta-analysis was performed according to the PRISMA statement. We searched MEDLINE, Web of Science and the Cochrane Library from inception to September 2015. All prospective studies of the diagnostic accuracy of ultrasound versus radiography as the reference standard were included. We excluded studies with a retrospective design and those with evidence of verification bias. We assessed the methodological quality of the included studies with the QUADAS-2 tool. We performed a meta-analysis of studies evaluating ultrasound to calculate the pooled sensitivity and specificity with 95% confidence intervals (CI95%) using a bivariate model with random effects. Subgroup and sensitivity analysis were used to examine the effect of methodological differences and other study characteristics. Results Out of 867 publications we included 16 studies with 1,204 patients and 641 fractures. The pooled test characteristics for ultrasound were: sensitivity 97% (CI95% 93–99%), specificity 95% (CI95% 89–98%), positive likelihood ratio (LR) 20.0 (8.5–47.2) and negative LR 0.03 (0.01–0.08). The corresponding pooled diagnostic odds ratio (DOR) was 667 (142–3,133). Apparent differences were shown for method of viewing, with the 6-view method showing higher specificity, positive LR, and DOR, compared to the 4-view method. Conclusion The present meta-analysis showed that ultrasound has a high accuracy for the diagnosis of distal forearm fractures in children when used by proper viewing method. Based on this, ultrasound should be considered a reliable alternative, which has the advantages of being radiation free. PMID:27196439

Diagnostic Accuracy of Periapical Radiography and Cone-beam Computed Tomography in Identifying Root Canal Configuration of Human Premolars.

PubMed

Sousa, Thiago Oliveira; Haiter-Neto, Francisco; Nascimento, Eduarda Helena Leandro; Peroni, Leonardo Vieira; Freitas, Deborah Queiroz; Hassan, Bassam

2017-07-01

The aim of this study was to assess the diagnostic accuracy of periapical radiography (PR) and cone-beam computed tomographic (CBCT) imaging in the detection of the root canal configuration (RCC) of human premolars. PR and CBCT imaging of 114 extracted human premolars were evaluated by 2 oral radiologists. RCC was recorded according to Vertucci's classification. Micro-computed tomographic imaging served as the gold standard to determine RCC. Accuracy, sensitivity, specificity, and predictive values were calculated. The Friedman test compared both PR and CBCT imaging with the gold standard. CBCT imaging showed higher values for all diagnostic tests compared with PR. Accuracy was 0.55 and 0.89 for PR and CBCT imaging, respectively. There was no difference between CBCT imaging and the gold standard, whereas PR differed from both CBCT and micro-computed tomographic imaging (P < .0001). CBCT imaging was more accurate than PR for evaluating different types of RCC individually. Canal configuration types III, VII, and "other" were poorly identified on CBCT imaging with a detection accuracy of 50%, 0%, and 43%, respectively. With PR, all canal configurations except type I were poorly visible. PR presented low performance in the detection of RCC in premolars, whereas CBCT imaging showed no difference compared with the gold standard. Canals with complex configurations were less identifiable using both imaging methods, especially PR. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A whole-heart motion-correction algorithm: Effects on CT image quality and diagnostic accuracy of mechanical valve prosthesis abnormalities.

PubMed

Suh, Young Joo; Kim, Young Jin; Kim, Jin Young; Chang, Suyon; Im, Dong Jin; Hong, Yoo Jin; Choi, Byoung Wook

2017-11-01

We aimed to determine the effect of a whole-heart motion-correction algorithm (new-generation snapshot freeze, NG SSF) on the image quality of cardiac computed tomography (CT) images in patients with mechanical valve prostheses compared to standard images without motion correction and to compare the diagnostic accuracy of NG SSF and standard CT image sets for the detection of prosthetic valve abnormalities. A total of 20 patients with 32 mechanical valves who underwent wide-coverage detector cardiac CT with single-heartbeat acquisition were included. The CT image quality for subvalvular (below the prosthesis) and valvular regions (valve leaflets) of mechanical valves was assessed by two observers on a four-point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent). Paired t-tests or Wilcoxon signed rank tests were used to compare image quality scores and the number of diagnostic phases (image quality score≥3) between the standard image sets and NG SSF image sets. Diagnostic performance for detection of prosthetic valve abnormalities was compared between two image sets with the final diagnosis set by re-operation or clinical findings as the standard reference. NG SSF image sets had better image quality scores than standard image sets for both valvular and subvalvular regions (P < 0.05 for both). The number of phases that were of diagnostic image quality per patient was significantly greater in the NG SSF image set than standard image set for both valvular and subvalvular regions (P < 0.0001). Diagnostic performance of NG SSF image sets for the detection of prosthetic abnormalities (20 pannus and two paravalvular leaks) was greater than that of standard image sets (P < 0.05). Application of NG SSF can improve CT image quality and diagnostic accuracy in patients with mechanical valves compared to standard images. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

The Autism Diagnostic Observation Schedule, Module 4: Revised Algorithm and Standardized Severity Scores

ERIC Educational Resources Information Center

Hus, Vanessa; Lord, Catherine

2014-01-01

The recently published Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2) includes revised diagnostic algorithms and standardized severity scores for modules used to assess younger children. A revised algorithm and severity scores are not yet available for Module 4, used with verbally fluent adults. The current study revises the Module 4…

Sensitivity and diagnosticity of NASA-TLX and simplified SWAT to assess the mental workload associated with operating an agricultural sprayer.

PubMed

Dey, Asit; Mann, Danny D

2010-07-01

The objectives of the present study were: a) to investigate three continuous variants of the NASA-Task Load Index (TLX) (standard NASA (CNASA), average NASA (C1NASA) and principal component NASA (PCNASA)) and five different variants of the simplified subjective workload assessment technique (SSWAT) (continuous standard SSWAT (CSSWAT), continuous average SSWAT (C1SSWAT), continuous principal component SSWAT (PCSSWAT), discrete event-based SSWAT (D1SSWAT) and discrete standard SSWAT (DSSWAT)) in terms of their sensitivity and diagnosticity to assess the mental workload associated with agricultural spraying; b) to compare and select the best variants of NASA-TLX and SSWAT for future mental workload research in the agricultural domain. A total of 16 male university students (mean 30.4 +/- 12.5 years) participated in this study. All the participants were trained to drive an agricultural spraying simulator. Sensitivity was assessed by the ability of the scales to report the maximum change in workload ratings due to the change in illumination and difficulty levels. In addition, the factor loading method was used to quantify sensitivity. The diagnosticity was assessed by the ability of the scale to diagnose the change in task levels from single to dual. Among all the variants of NASA-TLX and SSWAT, PCNASA and discrete variants of SSWAT showed the highest sensitivity and diagnosticity. Moreover, among all the variants of NASA and SSWAT, the discrete variants of SSWAT showed the highest sensitivity and diagnosticity but also high between-subject variability. The continuous variants of both scales had relatively low sensitivity and diagnosticity and also low between-subject variability. Hence, when selecting a scale for future mental workload research in the agricultural domain, a researcher should decide what to compromise: 1) between-subject variability or 2) sensitivity and diagnosticity. STATEMENT OF RELEVANCE: The use of subjective workload scales is very popular in mental workload research. The present study investigated the different variants of two popular workload rating scales (i.e. NASA-TLX and SSWAT) in terms of their sensitivity and diagnositicity and selected the best variants of each scale for future mental workload research.

Clinical Diagnostic Utility of IP-10 and LAM Antigen Levels for the Diagnosis of Tuberculous Pleural Effusions in a High Burden Setting

PubMed Central

Dheda, Keertan; Van-Zyl Smit, Richard N.; Sechi, Leonardo A.; Badri, Motasim; Meldau, Richard; Symons, Gregory; Khalfey, Hoosein; Carr, Igshaan; Maredza, Alice; Dawson, Rodney; Wainright, Helen; Whitelaw, Andrew; Bateman, Eric D.; Zumla, Alimuddin

2009-01-01

Background Current tools for the diagnosis of tuberculosis pleural effusions are sub-optimal. Data about the value of new diagnostic technologies are limited, particularly, in high burden settings. Preliminary case control studies have identified IFN-γ-inducible-10kDa protein (IP-10) as a promising diagnostic marker; however, its diagnostic utility in a day-to-day clinical setting is unclear. Detection of LAM antigen has not previously been evaluated in pleural fluid. Methods We investigated the comparative diagnostic utility of established (adenosine deaminase [ADA]), more recent (standardized nucleic-acid-amplification-test [NAAT]) and newer technologies (a standardized LAM mycobacterial antigen-detection assay and IP-10 levels) for the evaluation of pleural effusions in 78 consecutively recruited South African tuberculosis suspects. All consenting participants underwent pleural biopsy unless contra-indicated or refused. The reference standard comprised culture positivity for M. tuberculosis or histology suggestive of tuberculosis. Principal Findings Of 74 evaluable subjects 48, 7 and 19 had definite, probable and non-TB, respectively. IP-10 levels were significantly higher in TB vs non-TB participants (p<0.0001). The respective outcomes [sensitivity, specificity, PPV, NPV %] for the different diagnostic modalities were: ADA at the 30 IU/L cut-point [96; 69; 90; 85], NAAT [6; 93; 67; 28], IP-10 at the 28,170 pg/ml ROC-derived cut-point [80; 82; 91; 64], and IP-10 at the 4035 pg/ml cut-point [100; 53; 83; 100]. Thus IP-10, using the ROC-derived cut-point, missed ∼20% of TB cases and mis-diagnosed ∼20% of non-TB cases. By contrast, when a lower cut-point was used a negative test excluded TB. The NAAT had a poor sensitivity but high specificity. LAM antigen-detection was not diagnostically useful. Conclusion Although IP-10, like ADA, has sub-optimal specificity, it may be a clinically useful rule-out test for tuberculous pleural effusions. Larger multi-centric studies are now required to confirm our findings. PMID:19277111

Performance of a Method to Standardize Breast Ultrasound Interpretation Using Image Processing and Case-Based Reasoning

NASA Astrophysics Data System (ADS)

André, M. P.; Galperin, M.; Berry, A.; Ojeda-Fournier, H.; O'Boyle, M.; Olson, L.; Comstock, C.; Taylor, A.; Ledgerwood, M.

Our computer-aided diagnostic (CADx) tool uses advanced image processing and artificial intelligence to analyze findings on breast sonography images. The goal is to standardize reporting of such findings using well-defined descriptors and to improve accuracy and reproducibility of interpretation of breast ultrasound by radiologists. This study examined several factors that may impact accuracy and reproducibility of the CADx software, which proved to be highly accurate and stabile over several operating conditions.

High sensitivity, high surface area Enzyme-linked Immunosorbent Assay (ELISA).

PubMed

Singh, Harpal; Morita, Takahiro; Suzuki, Yuma; Shimojima, Masayuki; Le Van, An; Sugamata, Masami; Yang, Ming

2015-01-01

Enzyme-linked immunosorbent assays (ELISA) are considered the gold standard in the demonstration of various immunological reactions with an application in the detection of infectious diseases such as during outbreaks or in patient care. This study aimed to produce an ELISA-based diagnostic with an increased sensitivity of detection compared to the standard 96-well method in the immunologic diagnosis of infectious diseases. A '3DStack' was developed using readily available, low cost fabrication technologies namely nanoimprinting and press stamping with an increased surface area of 4 to 6 times more compared to 96-well plates. This was achieved by stacking multiple nanoimprinted polymer sheets. The flow of analytes between the sheets was enhanced by rotating the 3DStack and confirmed by Finite-Element (FE) simulation. An Immunoglobulin G (IgG) ELISA for the detection of antibodies in human serum raised against Rubella virus was performed for validation. An improved sensitivity of up to 1.9 folds higher was observed using the 3DStack compared to the standard method. The increased surface area of the 3DStack developed using nanoimprinting and press stamping technologies, and the flow pattern between sheets generated by rotating the 3DStack were potential contributors to a more sensitive ELISA-based diagnostic device.

Ocular toxocariasis: new diagnostic and therapeutic perspectives.

PubMed

Martínez-Pulgarín, Dayron F; Muñoz-Urbano, Marcela; Gomez-Suta, Luz D; Delgado, Olinda M; Rodriguez-Morales, Alfonso J

2015-01-01

To provide an updated insight of concepts regarding the overview, epidemiology, risk factors, clinical manifestations, diagnosis, treatment and prevention of ocular toxocariasis. Perspective of literature review. Review and synthesis of literature about toxocariasis, with interpretation and perspective. A literature search for "ocular toxocariasis" was performed using PubMed, ScienceDirect, Scopus, SciELO and LILACS databases. Mild to moderate infections are frequently reported in ocular toxocariasis which usually occurs in children and typically presents as unilateral vision impairment, blindness is common and could present invasion of the retina. There are three groups of presentation of toxocariasis (according to the physical examination): chronic endophthalmitis, posterior granuloma and peripheral granuloma. Standard diagnosis of ocular toxocariasis is based on the identification of clinical signs, supported by additional diagnostic methods. Regarding treatment, there is no commonly accepted regimen but most of the authors prefer to use steroids and anthelminthic agents, but nowadays there are no standardized parameters in terms of dosage, duration and route of administration. Surgery has been recommended in some cases. Toxocariasis is still a problem of public health, particularly in developing countries with an increasing epidemiological burden in terms of morbidity and mortality and most of the authors agree on the utmost relevance of its prevention. Clinical experience and suspicion of ophthalmologists make an important role in its diagnosis, but always with supportive diagnostic methods. Additional studies should explore new therapeutic options for toxocariasis.

Preliminary evaluation of a gel tube agglutination major cross-match method in dogs.

PubMed

Villarnovo, Dania; Burton, Shelley A; Horney, Barbara S; MacKenzie, Allan L; Vanderstichel, Raphaël

2016-09-01

A major cross-match gel tube test is available for use in dogs yet has not been clinically evaluated. This study compared cross-match results obtained using the gel tube and the standard tube methods for canine samples. Study 1 included 107 canine sample donor-recipient pairings cross-match tested with the RapidVet-H method gel tube test and compared results with the standard tube method. Additionally, 120 pairings using pooled sera containing anti-canine erythrocyte antibody at various concentrations were tested with leftover blood from a hospital population to assess sensitivity and specificity of the gel tube method in comparison with the standard method. The gel tube method had a good relative specificity of 96.1% in detecting lack of agglutination (compatibility) compared to the standard tube method. Agreement between the 2 methods was moderate. Nine of 107 pairings showed agglutination/incompatibility on either test, too few to allow reliable calculation of relative sensitivity. Fifty percent of the gel tube method results were difficult to interpret due to sample spreading in the reaction and/or negative control tubes. The RapidVet-H method agreed with the standard cross-match method on compatible samples, but detected incompatibility in some sample pairs that were compatible with the standard method. Evaluation using larger numbers of incompatible pairings is needed to assess diagnostic utility. The gel tube method results were difficult to categorize due to sample spreading. Weak agglutination reactions or other factors such as centrifuge model may be responsible. © 2016 American Society for Veterinary Clinical Pathology.

Artificial neural networks for processing fluorescence spectroscopy data in skin cancer diagnostics

NASA Astrophysics Data System (ADS)

Lenhardt, L.; Zeković, I.; Dramićanin, T.; Dramićanin, M. D.

2013-11-01

Over the years various optical spectroscopic techniques have been widely used as diagnostic tools in the discrimination of many types of malignant diseases. Recently, synchronous fluorescent spectroscopy (SFS) coupled with chemometrics has been applied in cancer diagnostics. The SFS method involves simultaneous scanning of both emission and excitation wavelengths while keeping the interval of wavelengths (constant-wavelength mode) or frequencies (constant-energy mode) between them constant. This method is fast, relatively inexpensive, sensitive and non-invasive. Total synchronous fluorescence spectra of normal skin, nevus and melanoma samples were used as input for training of artificial neural networks. Two different types of artificial neural networks were trained, the self-organizing map and the feed-forward neural network. Histopathology results of investigated skin samples were used as the gold standard for network output. Based on the obtained classification success rate of neural networks, we concluded that both networks provided high sensitivity with classification errors between 2 and 4%.

Adherence to Standards for Reporting Diagnostic Accuracy in Emergency Medicine Research.

PubMed

Gallo, Lucas; Hua, Nadia; Mercuri, Mathew; Silveira, Angela; Worster, Andrew

2017-08-01

Diagnostic tests are used frequently in the emergency department (ED) to guide clinical decision making and, hence, influence clinical outcomes. The Standards for Reporting of Diagnostic Accuracy (STARD) criteria were developed to ensure that diagnostic test studies are performed and reported to best inform clinical decision making in the ED. The objective was to determine the extent to which diagnostic studies published in emergency medicine journals adhered to STARD 2003 criteria. Diagnostic studies published in eight MEDLINE-listed, peer-reviewed, emergency medicine journals over a 5-year period were reviewed for compliance to STARD criteria. A total of 12,649 articles were screened and 114 studies were included in our study. Twenty percent of these were randomly selected for assessment using STARD 2003 criteria. Adherence to STARD 2003 reporting standards for each criteria ranged from 8.7% adherence (criteria-reporting adverse events from performing index test or reference standard) to 100% (multiple criteria). Just over half of STARD criteria are reported in more than 80% studies. As poorly reported studies may negatively impact their clinical usefulness, it is essential that studies of diagnostic test accuracy be performed and reported adequately. Future studies should assess whether studies have improved compliance with the STARD 2015 criteria amendment. © 2017 by the Society for Academic Emergency Medicine.

21 CFR 660.43 - Potency test.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Potency test. 660.43 Section 660.43 Food and Drugs... STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Hepatitis B Surface Antigen § 660.43 Potency test... antibody in the appropriate sera of the reference panel by all test methods recommended by the manufacturer...

Diagnostic Imaging of the Hepatobiliary System: An Update.

PubMed

Marolf, Angela J

2017-05-01

Recent advances in diagnostic imaging of the hepatobiliary system include MRI, computed tomography (CT), contrast-enhanced ultrasound, and ultrasound elastography. With the advent of multislice CT scanners, sedated examinations in veterinary patients are feasible, increasing the utility of this imaging modality. CT and MRI provide additional information for dogs and cats with hepatobiliary diseases due to lack of superimposition of structures, operator dependence, and through intravenous contrast administration. Advanced ultrasound methods can offer complementary information to standard ultrasound imaging. These newer imaging modalities assist clinicians by aiding diagnosis, prognostication, and surgical planning. Copyright © 2016 Elsevier Inc. All rights reserved.

Molecular methods for somatic mutation testing in lung adenocarcinoma: EGFR and beyond

PubMed Central

Rogers, Toni-Maree; Fellowes, Andrew; Bell, Anthony; Fox, Stephen

2015-01-01

Somatic mutational profiling in cancer has revolutionized the practice of clinical oncology. The discovery of driver mutations in non-small cell lung cancer (NSCLC) is an example of this. Molecular testing of lung adenocarcinoma is now considered standard of care and part of the diagnostic algorithm. This article provides an overview of the workflow of molecular testing in a clinical diagnostic laboratory discussing in particular novel assays that are currently in use for somatic mutation detection in NSCLC focussing on epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK), ROS1 and RET rearrangements. PMID:25870795

Computer-assisted assessment of ultrasound real-time elastography: initial experience in 145 breast lesions.

PubMed

Zhang, Xue; Xiao, Yang; Zeng, Jie; Qiu, Weibao; Qian, Ming; Wang, Congzhi; Zheng, Rongqin; Zheng, Hairong

2014-01-01

To develop and evaluate a computer-assisted method of quantifying five-point elasticity scoring system based on ultrasound real-time elastography (RTE), for classifying benign and malignant breast lesions, with pathologic results as the reference standard. Conventional ultrasonography (US) and RTE images of 145 breast lesions (67 malignant, 78 benign) were performed in this study. Each lesion was automatically contoured on the B-mode image by the level set method and mapped on the RTE image. The relative elasticity value of each pixel was reconstructed and classified into hard or soft by the fuzzy c-means clustering method. According to the hardness degree inside lesion and its surrounding tissue, the elasticity score of the RTE image was computed in an automatic way. Visual assessments of the radiologists were used for comparing the diagnostic performance. Histopathologic examination was used as the reference standard. The Student's t test and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis. Considering score 4 or higher as test positive for malignancy, the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 93.8% (136/145), 92.5% (62/67), 94.9% (74/78), 93.9% (62/66), and 93.7% (74/79) for the computer-assisted scheme, and 89.7% (130/145), 85.1% (57/67), 93.6% (73/78), 92.0% (57/62), and 88.0% (73/83) for manual assessment. Area under ROC curve (Az value) for the proposed method was higher than the Az value for visual assessment (0.96 vs. 0.93). Computer-assisted quantification of classical five-point scoring system can significantly eliminate the interobserver variability and thereby improve the diagnostic confidence of classifying the breast lesions to avoid unnecessary biopsy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Role of chromatography in the development of Standard Reference Materials for organic analysis.

PubMed

Wise, Stephen A; Phinney, Karen W; Sander, Lane C; Schantz, Michele M

2012-10-26

The certification of chemical constituents in natural-matrix Standard Reference Materials (SRMs) at the National Institute of Standards and Technology (NIST) can require the use of two or more independent analytical methods. The independence among the methods is generally achieved by taking advantage of differences in extraction, separation, and detection selectivity. This review describes the development of the independent analytical methods approach at NIST, and its implementation in the measurement of organic constituents such as contaminants in environmental materials, nutrients and marker compounds in food and dietary supplement matrices, and health diagnostic and nutritional assessment markers in human serum. The focus of this review is the important and critical role that separation science techniques play in achieving the necessary independence of the analytical steps in the measurement of trace-level organic constituents in natural matrix SRMs. Published by Elsevier B.V.

Comparing Diagnostic Accuracy of Kato-Katz, Koga Agar Plate, Ether-Concentration, and FLOTAC for Schistosoma mansoni and Soil-Transmitted Helminths

PubMed Central

Glinz, Dominik; Silué, Kigbafori D.; Knopp, Stefanie; Lohourignon, Laurent K.; Yao, Kouassi P.; Steinmann, Peter; Rinaldi, Laura; Cringoli, Giuseppe; N'Goran, Eliézer K.; Utzinger, Jürg

2010-01-01

Background Infections with schistosomes and soil-transmitted helminths exert a considerable yet underappreciated economic and public health burden on afflicted populations. Accurate diagnosis is crucial for patient management, drug efficacy evaluations, and monitoring of large-scale community-based control programs. Methods/Principal Findings The diagnostic accuracy of four copromicroscopic techniques (i.e., Kato-Katz, Koga agar plate, ether-concentration, and FLOTAC) for the detection of Schistosoma mansoni and soil-transmitted helminth eggs was compared using stool samples from 112 school children in Côte d'Ivoire. Combined results of all four methods served as a diagnostic ‘gold’ standard and revealed prevalences of S. mansoni, hookworm, Trichuris trichiura, Strongyloides stercoralis and Ascaris lumbricoides of 83.0%, 55.4%, 40.2%, 33.9% and 28.6%, respectively. A single FLOTAC from stool samples preserved in sodium acetate-acetic acid-formalin for 30 or 83 days showed a higher sensitivity for S. mansoni diagnosis (91.4%) than the ether-concentration method on stool samples preserved for 40 days (85.0%) or triplicate Kato-Katz using fresh stool samples (77.4%). Moreover, a single FLOTAC detected hookworm, A. lumbricoides and T. trichiura infections with a higher sensitivity than any of the other methods used, but resulted in lower egg counts. The Koga agar plate method was the most accurate diagnostic assay for S. stercoralis. Conclusion/Significance We have shown that the FLOTAC method holds promise for the diagnosis of S. mansoni. Moreover, our study confirms that FLOTAC is a sensitive technique for detection of common soil-transmitted helminths. For the diagnosis of S. stercoralis, the Koga agar plate method remains the method of choice. PMID:20651931

New diagnostic reporting format for endometrial cytology based on cytoarchitectural criteria

PubMed Central

Yanoh, K; Norimatsu, Y; Hirai, Y; Takeshima, N; Kamimori, A; Nakamura, Y; Shimizu, K; Kobayashi, T K; Murata, T; Shiraishi, T

2009-01-01

Objective: The aim of this study was to develop a new reporting format for endometrial cytology that would standardize the diagnostic criteria and the terminology used for reporting. Methods: In previous studies, cytoarchitectural criteria were found to be useful for the cytological assessment of endometrial lesions. To apply these criteria, an appropriate cytological specimen is imperative. In this article, the requirements of an adequate endometrial cytological specimen for the new diagnostic criteria are first discussed. Then, the diagnostic criteria, standardized on a combination of conventional and cytoarchitectural criteria, are presented. Third, terminology that could be used, not only for reporting the histopathological diagnosis, but also for providing better guidance for the gynaecologist to determine further clinical action, is introduced. The proposed reporting format was investigated using endometrial cytology of 58 cases that were cytologically underestimated or overestimated compared to the histopathological diagnosis made on the subsequent endometrial biopsy or surgical specimens. Results: Of the 58 cases, 12 were reassessed as being unsatisfactory for evaluation. Among the remaining 46 cases, 25 of the 27 cases, which had been underestimated and subsequently diagnosed as having endometrial carcinoma or a precursor stage on histopathological examination,were reassessed as recommended for endometrial biopsy. On the other hand, 19 cases overestimated by cytology were all reassessed as not requiring biopsy. Conclusions: The reporting format for endometrial cytology proposed in this article may improve diagnostic accuracy and reduce the number of patients managed inappropriately. PMID:18657157

Modeling Canadian Quality Control Test Program for Steroid Hormone Receptors in Breast Cancer: Diagnostic Accuracy Study.

PubMed

Pérez, Teresa; Makrestsov, Nikita; Garatt, John; Torlakovic, Emina; Gilks, C Blake; Mallett, Susan

The Canadian Immunohistochemistry Quality Control program monitors clinical laboratory performance for estrogen receptor and progesterone receptor tests used in breast cancer treatment management in Canada. Current methods assess sensitivity and specificity at each time point, compared with a reference standard. We investigate alternative performance analysis methods to enhance the quality assessment. We used 3 methods of analysis: meta-analysis of sensitivity and specificity of each laboratory across all time points; sensitivity and specificity at each time point for each laboratory; and fitting models for repeated measurements to examine differences between laboratories adjusted by test and time point. Results show 88 laboratories participated in quality control at up to 13 time points using typically 37 to 54 histology samples. In meta-analysis across all time points no laboratories have sensitivity or specificity below 80%. Current methods, presenting sensitivity and specificity separately for each run, result in wide 95% confidence intervals, typically spanning 15% to 30%. Models of a single diagnostic outcome demonstrated that 82% to 100% of laboratories had no difference to reference standard for estrogen receptor and 75% to 100% for progesterone receptor, with the exception of 1 progesterone receptor run. Laboratories with significant differences to reference standard identified with Generalized Estimating Equation modeling also have reduced performance by meta-analysis across all time points. The Canadian Immunohistochemistry Quality Control program has a good design, and with this modeling approach has sufficient precision to measure performance at each time point and allow laboratories with a significantly lower performance to be targeted for advice.

Sixty-five years since the New York heat wave: advances in sweat testing for cystic fibrosis.

PubMed

Collie, Jake T B; Massie, R John; Jones, Oliver A H; LeGrys, Vicky A; Greaves, Ronda F

2014-02-01

The sweat test remains important as a diagnostic test for cystic fibrosis (CF) and has contributed greatly to our understanding of CF as a disease of epithelial electrolyte transport. The standardization of the sweat test, by Gibson and Cooke [Gibson and Cooke (1959) Pediatrics 1959;23:5], followed observations of excessive dehydration amongst patients with CF and confirmed the utility as a diagnostic test. Quantitative pilocarpine iontophoresis remains the gold standard for sweat induction, but there are a number of collection and analytical methods. The pathophysiology of electrolyte transport in sweat was described by Quinton [Quinton (1983) Nature 1983;301:421-422], and this complemented the developments in genetics that discovered the cystic fibrosis transmembrane conductance regulator (CFTR), an epithelial-based electrolyte transport protein. Knowledge of CF has since increased rapidly and further developments in sweat testing include: new collection methods, further standardization of the technique with international recommendations and age related reference intervals. More recently, sweat chloride values have been used as proof of effect for the new drugs that activate CFTR. However, there remain issues with adherence to sweat test guidelines in many countries and there are gaps in our knowledge, including reference intervals for some age groups and stability of sweat samples in transport. Furthermore, modern methods of elemental quantification need to be explored as alternatives to the original analytical methods for sweat electrolyte measurement. The purpose of this review is therefore to describe the development of the sweat test and consider future directions. © 2013 Wiley Periodicals, Inc.

Reference Standard Test and the Diagnostic Ability of Spectral Domain Optical Coherence Tomography in Glaucoma.

PubMed

Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Begum, Viquar U; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

2015-08-01

To evaluate the relationship between the reference standard used to diagnose glaucoma and the diagnostic ability of spectral domain optical coherence tomograph (SDOCT). In a cross-sectional study, 280 eyes of 175 consecutive subjects, referred to a tertiary eye care center for glaucoma evaluation, underwent optic disc photography, visual field (VF) examination, and SDOCT examination. The cohort was divided into glaucoma and control groups based on 3 reference standards for glaucoma diagnosis: first based on the optic disc classification (179 glaucoma and 101 control eyes), second on VF classification (glaucoma hemifield test outside normal limits and pattern SD with P-value of <5%, 130 glaucoma and 150 control eyes), and third on the presence of both glaucomatous optic disc and glaucomatous VF (125 glaucoma and 155 control eyes). Relationship between the reference standards and the diagnostic parameters of SDOCT were evaluated using areas under the receiver operating characteristic curve, sensitivity, and specificity. Areas under the receiver operating characteristic curve and sensitivities of most of the SDOCT parameters obtained with the 3 reference standards (ranging from 0.74 to 0.88 and 72% to 88%, respectively) were comparable (P>0.05). However, specificities of SDOCT parameters were significantly greater (P<0.05) with optic disc classification as reference standard (74% to 88%) compared with VF classification as reference standard (57% to 74%). Diagnostic parameters of SDOCT that was significantly affected by reference standard was the specificity, which was greater with optic disc classification as the reference standard. This has to be considered when comparing the diagnostic ability of SDOCT across studies.

Tuberculosis Management Practices by Private Practitioners in Andhra Pradesh, India

PubMed Central

Achanta, Shanta; Jaju, Jyoti; Kumar, Ajay M. V.; Nagaraja, Sharath Burugina; Shamrao, Srinivas Rao Motta; Bandi, Sasidhar Kumar; Kumar, Ashok; Satyanarayana, Srinath; Harries, Anthony David; Nair, Sreenivas Achutan; Dewan, Puneet K.

2013-01-01

Setting Private medical practitioners in Visakhapatnam district, Andhra Pradesh, India. Objectives To evaluate self-reported TB diagnostic and treatment practices amongst private medical practitioners against benchmark practices articulated in the International Standards of Tuberculosis Care (ISTC), and factors associated with compliance with ISTC. Design Cross- sectional survey using semi-structured interviews. Results Of 296 randomly selected private practitioners, 201 (68%) were assessed for compliance to ISTC diagnostic and treatment standards in TB management. Only 11 (6%) followed a combination of 6 diagnostic standards together and only 1 followed a combination of all seven treatment standards together. There were 28 (14%) private practitioners who complied with a combination of three core ISTC (cough for tuberculosis suspects, sputum smear examination and use of standardized treatment). Higher ISTC compliance was associated with caring for more than 20 TB patients annually, prior sensitization to TB control guidelines, and practice of alternate systems of medicine. Conclusion Few private practitioners in Visakhapatnam, India reported TB diagnostic and treatment practices that met ISTC. Better engagement of the private sector is urgently required to improve TB management practices and to prevent diagnostic delay and drug resistance. PMID:23967158

Intelligent model-based diagnostics for vehicle health management

NASA Astrophysics Data System (ADS)

Luo, Jianhui; Tu, Fang; Azam, Mohammad S.; Pattipati, Krishna R.; Willett, Peter K.; Qiao, Liu; Kawamoto, Masayuki

2003-08-01

The recent advances in sensor technology, remote communication and computational capabilities, and standardized hardware/software interfaces are creating a dramatic shift in the way the health of vehicles is monitored and managed. These advances facilitate remote monitoring, diagnosis and condition-based maintenance of automotive systems. With the increased sophistication of electronic control systems in vehicles, there is a concomitant increased difficulty in the identification of the malfunction phenomena. Consequently, the current rule-based diagnostic systems are difficult to develop, validate and maintain. New intelligent model-based diagnostic methodologies that exploit the advances in sensor, telecommunications, computing and software technologies are needed. In this paper, we will investigate hybrid model-based techniques that seamlessly employ quantitative (analytical) models and graph-based dependency models for intelligent diagnosis. Automotive engineers have found quantitative simulation (e.g. MATLAB/SIMULINK) to be a vital tool in the development of advanced control systems. The hybrid method exploits this capability to improve the diagnostic system's accuracy and consistency, utilizes existing validated knowledge on rule-based methods, enables remote diagnosis, and responds to the challenges of increased system complexity. The solution is generic and has the potential for application in a wide range of systems.

Quality systems in veterinary diagnostics laboratories.

PubMed

de Branco, Freitas Maia L M

2007-01-01

Quality assurance of services provided by veterinary diagnostics laboratories is a fundamental element promoted by international animal health organizations to establish trust, confidence and transparency needed for the trade of animals and their products at domestic and international levels. It requires, among other things, trained personnel, consistent and rigorous methodology, choice of suitable methods as well as appropriate calibration and traceability procedures. An important part of laboratory quality management is addressed by ISO/IEC 17025, which aims to facilitate cooperation among laboratories and their associated parties by assuring the generation of credible and consistent information derived from analytical results. Currently, according to OIE recommendation, veterinary diagnostics laboratories are only subject to voluntary compliance with standard ISO/IEC 17025; however, it is proposed here that OIE reference laboratories and collaboration centres strongly consider its adoption.

Evaluation of a blocking ELISA for the detection of antibodies against Lawsonia intracellularis in pig sera.

PubMed

Jacobson, Magdalena; Wallgren, Per; Nordengrahn, Ann; Merza, Malik; Emanuelson, Ulf

2011-04-01

Lawsonia intracellularis is a common cause of chronic diarrhoea and poor performance in young growing pigs. Diagnosis of this obligate intracellular bacterium is based on the demonstration of the microbe or microbial DNA in tissue specimens or faecal samples, or the demonstration of L. intracellularis-specific antibodies in sera. The aim of the present study was to evaluate a blocking ELISA in the detection of serum antibodies to L. intracellularis, by comparison to the previously widely used immunofluorescent antibody test (IFAT). Sera were collected from 176 pigs aged 8-12 weeks originating from 24 herds with or without problems with diarrhoea and poor performance in young growing pigs. Sera were analyzed by the blocking ELISA and by IFAT. Bayesian modelling techniques were used to account for the absence of a gold standard test and the results of the blocking ELISA was modelled against the IFAT test with a "2 dependent tests, 2 populations, no gold standard" model. At the finally selected cut-off value of percent inhibition (PI) 35, the diagnostic sensitivity of the blocking ELISA was 72% and the diagnostic specificity was 93%. The positive predictive value was 0.82 and the negative predictive value was 0.89, at the observed prevalence of 33.5%. The sensitivity and specificity as evaluated by Bayesian statistic techniques differed from that previously reported. Properties of diagnostic tests may well vary between countries, laboratories and among populations of animals. In the absence of a true gold standard, the importance of validating new methods by appropriate statistical methods and with respect to the target population must be emphasized.

The Standard for Clinicians’ Interview in Psychiatry (SCIP): A Clinician-administered Tool with Categorical, Dimensional, and Numeric Output—Conceptual Development, Design, and Description of the SCIP

PubMed Central

Nasrallah, Henry; Muvvala, Srinivas; El-Missiry, Ahmed; Mansour, Hader; Hill, Cheryl; Elswick, Daniel; Price, Elizabeth C.

2016-01-01

Existing standardized diagnostic interviews (SDIs) were designed for researchers and produce mainly categorical diagnoses. There is an urgent need for a clinician-administered tool that produces dimensional measures, in addition to categorical diagnoses. The Standard for Clinicians’ Interview in Psychiatry (SCIP) is a method of assessment of psychopathology for adults. It is designed to be administered by clinicians and includes the SCIP manual and the SCIP interview. Clinicians use the SCIP questions and rate the responses according to the SCIP manual rules. Clinicians use the patient’s responses to questions, observe the patient’s behaviors and make the final rating of the various signs and symptoms assessed. The SCIP method of psychiatric assessment has three components: 1) the SCIP interview (dimensional) component, 2) the etiological component, and 3) the disorder classification component. The SCIP produces three main categories of clinical data: 1) a diagnostic classification of psychiatric disorders, 2) dimensional scores, and 3) numeric data. The SCIP provides diagnoses consistent with criteria from editions of the Diagnostic and Statistical Manual (DSM) and International Classification of Disease (ICD). The SCIP produces 18 dimensional measures for key psychiatric signs or symptoms: anxiety, posttraumatic stress, obsessions, compulsions, depression, mania, suicidality, suicidal behavior, delusions, hallucinations, agitation, disorganized behavior, negativity, catatonia, alcohol addiction, drug addiction, attention, and hyperactivity. The SCIP produces numeric severity data for use in either clinical care or research. The SCIP was shown to be a valid and reliable assessment tool, and the validity and reliability results were published in 2014 and 2015. The SCIP is compatible with personalized psychiatry research and is in line with the Research Domain Criteria framework. PMID:27800284

The Standard for Clinicians' Interview in Psychiatry (SCIP): A Clinician-administered Tool with Categorical, Dimensional, and Numeric Output-Conceptual Development, Design, and Description of the SCIP.

PubMed

Aboraya, Ahmed; Nasrallah, Henry; Muvvala, Srinivas; El-Missiry, Ahmed; Mansour, Hader; Hill, Cheryl; Elswick, Daniel; Price, Elizabeth C

2016-01-01

Existing standardized diagnostic interviews (SDIs) were designed for researchers and produce mainly categorical diagnoses. There is an urgent need for a clinician-administered tool that produces dimensional measures, in addition to categorical diagnoses. The Standard for Clinicians' Interview in Psychiatry (SCIP) is a method of assessment of psychopathology for adults. It is designed to be administered by clinicians and includes the SCIP manual and the SCIP interview. Clinicians use the SCIP questions and rate the responses according to the SCIP manual rules. Clinicians use the patient's responses to questions, observe the patient's behaviors and make the final rating of the various signs and symptoms assessed. The SCIP method of psychiatric assessment has three components: 1) the SCIP interview (dimensional) component, 2) the etiological component, and 3) the disorder classification component. The SCIP produces three main categories of clinical data: 1) a diagnostic classification of psychiatric disorders, 2) dimensional scores, and 3) numeric data. The SCIP provides diagnoses consistent with criteria from editions of the Diagnostic and Statistical Manual (DSM) and International Classification of Disease (ICD). The SCIP produces 18 dimensional measures for key psychiatric signs or symptoms: anxiety, posttraumatic stress, obsessions, compulsions, depression, mania, suicidality, suicidal behavior, delusions, hallucinations, agitation, disorganized behavior, negativity, catatonia, alcohol addiction, drug addiction, attention, and hyperactivity. The SCIP produces numeric severity data for use in either clinical care or research. The SCIP was shown to be a valid and reliable assessment tool, and the validity and reliability results were published in 2014 and 2015. The SCIP is compatible with personalized psychiatry research and is in line with the Research Domain Criteria framework.

Standard CMMI (Registered Trademark) Appraisal Method for Process Improvement (SCAMPI (Service Mark)) A, Version 1.3: Method Definition Document

DTIC Science & Technology

2011-03-01

performance of Federal Government Contract Number FA8721-05- C -0003 with Carnegie Mellon University for the operation of the Software Engineering... C Roles and Responsibilities 195 Appendix D Reporting Requirements and Options 201 Appendix E Managed Discovery 203 Appendix F Scoping and...Upgrade Team (SUT) • Mary Busby , Lockheed Martin • Palma Buttles-Valdez, Software Engineering Institute • Paul Byrnes, Integrated System Diagnostics

Decision analysis to complete diagnostic research by closing the gap between test characteristics and cost-effectiveness.

PubMed

Schaafsma, Joanna D; van der Graaf, Yolanda; Rinkel, Gabriel J E; Buskens, Erik

2009-12-01

The lack of a standard methodology in diagnostic research impedes adequate evaluation before implementation of constantly developing diagnostic techniques. We discuss the methodology of diagnostic research and underscore the relevance of decision analysis in the process of evaluation of diagnostic tests. Overview and conceptual discussion. Diagnostic research requires a stepwise approach comprising assessment of test characteristics followed by evaluation of added value, clinical outcome, and cost-effectiveness. These multiple goals are generally incompatible with a randomized design. Decision-analytic models provide an important alternative through integration of the best available evidence. Thus, critical assessment of clinical value and efficient use of resources can be achieved. Decision-analytic models should be considered part of the standard methodology in diagnostic research. They can serve as a valid alternative to diagnostic randomized clinical trials (RCTs).

A systematic review of the PTSD Checklist's diagnostic accuracy studies using QUADAS.

PubMed

McDonald, Scott D; Brown, Whitney L; Benesek, John P; Calhoun, Patrick S

2015-09-01

Despite the popularity of the PTSD Checklist (PCL) as a clinical screening test, there has been no comprehensive quality review of studies evaluating its diagnostic accuracy. A systematic quality assessment of 22 diagnostic accuracy studies of the English-language PCL using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) assessment tool was conducted to examine (a) the quality of diagnostic accuracy studies of the PCL, and (b) whether quality has improved since the 2003 STAndards for the Reporting of Diagnostic accuracy studies (STARD) initiative regarding reporting guidelines for diagnostic accuracy studies. Three raters independently applied the QUADAS tool to each study, and a consensus among the 4 authors is reported. Findings indicated that although studies generally met standards in several quality areas, there is still room for improvement. Areas for improvement include establishing representativeness, adequately describing clinical and demographic characteristics of the sample, and presenting better descriptions of important aspects of test and reference standard execution. Only 2 studies met each of the 14 quality criteria. In addition, study quality has not appreciably improved since the publication of the STARD Statement in 2003. Recommendations for the improvement of diagnostic accuracy studies of the PCL are discussed. (c) 2015 APA, all rights reserved).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, O.N.; Barone, G.J.

The Federal Performance Standard for Diagnostic X-ray Equipment, which became effective August 1, 1974, is primarily directed toward manufacturers, who must produce x-ray equipment that performs in a prescribed way. It is an equipment performance standard and does not reguate diagnostic x-ray uses. The dentist, however, has responsibilities in three areas - maintenance, assembly, and variance from the standard.

The Development of a Dental Diagnostic Terminology

PubMed Central

Kalenderian, Elsbeth; Ramoni, Rachel L.; White, Joel M.; Schoonheim-Klein, Meta E.; Stark, Paul C.; Kimmes, Nicole S.; Zeller, Gregory G.; Willis, George P.; Walji, Muhammad F.

2011-01-01

There is no commonly accepted standardized terminology for oral diagnoses. The purpose of this article is to report the development of a standardized dental diagnostic terminology by a work group of dental faculty members. The work group developed guiding principles for decision making and adhered to principles of terminology development. The members used an iterative process to develop a terminology incorporating concepts represented in the Toronto/University of California, San Francisco/Creighton University and International Classification of Diseases (ICD)-9/10 codes and periodontal and endodontic diagnoses. Domain experts were consulted to develop a final list of diagnostic terms. A structure was developed, consisting of thirteen categories, seventy-eight subcategories, and 1,158 diagnostic terms, hierarchically organized and mappable to other terminologies and ontologies. Use of this standardized diagnostic terminology will reinforce the diagnosis-treatment link and will facilitate clinical research, quality assurance, and patient communication. Future work will focus on implementation and approaches to enhance the validity and reliability of diagnostic term utilization. PMID:21205730

Electrically controlled microvalves to integrate microchip polymerase chain reaction and capillary electrophoresis.

PubMed

Kaigala, Govind V; Hoang, Viet N; Backhouse, Christopher J

2008-07-01

Microvalves are key in realizing portable miniaturized diagnostic platforms. We present a scalable microvalve that integrates well with standard lab on a chip (LOC) implementations, yet which requires essentially no external infrastructure for its operation. This electrically controlled, phase-change microvalve is used to integrate genetic amplification and analysis via capillary electrophoresis--the basis of many diagnostics. The microvalve is actuated using a polymer (polyethylene glycol, PEG) that exhibits a large volumetric change between its solid and liquid phases. Both the phase change of the PEG and the genetic amplification via polymerase chain reaction (PCR) are thermally controlled using thin film resistive elements that are patterned using standard microfabrication methods. By contrast with many other valve technologies, these microvalves and their control interface scale down in size readily. The novelty here lies in the use of fully integrated microvalves that require only electrical connections to realize a portable and inexpensive genetic analysis platform.

Application of laser Raman spectroscopy in concentration measurements of multiple analytes in human body fluids

NASA Astrophysics Data System (ADS)

Qu, Jianan Y.; Suria, David; Wilson, Brian C.

1998-05-01

The primary goal of these studies was to demonstrate that NIR Raman spectroscopy is feasible as a rapid and reagentless analytic method for clinical diagnostics. Raman spectra were collected on human serum and urine samples using a 785 nm excitation laser and a single-stage holographic spectrometer. A partial east squares method was used to predict the analyte concentrations of interest. The actual concentrations were determined by a standard clinical chemistry. The prediction accuracy of total protein, albumin, triglyceride and glucose in human sera ranged from 1.5 percent to 5 percent which is greatly acceptable for clinical diagnostics. The concentration measurements of acetaminophen, ethanol and codeine inhuman urine have demonstrated the potential of NIR Raman technology in screening of therapeutic drugs and substances of abuse.

Accuracy of LightCycler(R) SeptiFast for the detection and identification of pathogens in the blood of patients with suspected sepsis: a systematic review protocol.

PubMed

Dark, Paul; Wilson, Claire; Blackwood, Bronagh; McAuley, Danny F; Perkins, Gavin D; McMullan, Ronan; Gates, Simon; Warhurst, Geoffrey

2012-01-01

Background There is growing interest in the potential utility of molecular diagnostics in improving the detection of life-threatening infection (sepsis). LightCycler® SeptiFast is a multipathogen probe-based real-time PCR system targeting DNA sequences of bacteria and fungi present in blood samples within a few hours. We report here the protocol of the first systematic review of published clinical diagnostic accuracy studies of this technology when compared with blood culture in the setting of suspected sepsis. Methods/design Data sources: the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment Database (HTA), the NHS Economic Evaluation Database (NHSEED), The Cochrane Library, MEDLINE, EMBASE, ISI Web of Science, BIOSIS Previews, MEDION and the Aggressive Research Intelligence Facility Database (ARIF). diagnostic accuracy studies that compare the real-time PCR technology with standard culture results performed on a patient's blood sample during the management of sepsis. three reviewers, working independently, will determine the level of evidence, methodological quality and a standard data set relating to demographics and diagnostic accuracy metrics for each study. Statistical analysis/data synthesis: heterogeneity of studies will be investigated using a coupled forest plot of sensitivity and specificity and a scatter plot in Receiver Operator Characteristic (ROC) space. Bivariate model method will be used to estimate summary sensitivity and specificity. The authors will investigate reporting biases using funnel plots based on effective sample size and regression tests of asymmetry. Subgroup analyses are planned for adults, children and infection setting (hospital vs community) if sufficient data are uncovered. Dissemination Recommendations will be made to the Department of Health (as part of an open-access HTA report) as to whether the real-time PCR technology has sufficient clinical diagnostic accuracy potential to move forward to efficacy testing during the provision of routine clinical care. Registration PROSPERO-NIHR Prospective Register of Systematic Reviews (CRD42011001289).

Receiver operating characteristic analysis of eyewitness memory: comparing the diagnostic accuracy of simultaneous versus sequential lineups.

PubMed

Mickes, Laura; Flowe, Heather D; Wixted, John T

2012-12-01

A police lineup presents a real-world signal-detection problem because there are two possible states of the world (the suspect is either innocent or guilty), some degree of information about the true state of the world is available (the eyewitness has some degree of memory for the perpetrator), and a decision is made (identifying the suspect or not). A similar state of affairs applies to diagnostic tests in medicine because, in a patient, the disease is either present or absent, a diagnostic test yields some degree of information about the true state of affairs, and a decision is made about the presence or absence of the disease. In medicine, receiver operating characteristic (ROC) analysis is the standard method for assessing diagnostic accuracy. By contrast, in the eyewitness memory literature, this powerful technique has never been used. Instead, researchers have attempted to assess the diagnostic performance of different lineup procedures using methods that cannot identify the better procedure (e.g., by computing a diagnosticity ratio). Here, we describe the basics of ROC analysis, explaining why it is needed and showing how to use it to measure the performance of different lineup procedures. To illustrate the unique advantages of this technique, we also report 3 ROC experiments that were designed to investigate the diagnostic accuracy of simultaneous versus sequential lineups. According to our findings, the sequential procedure appears to be inferior to the simultaneous procedure in discriminating between the presence versus absence of a guilty suspect in a lineup.

Bayesian evaluation of clinical diagnostic test characteristics of visual observations and remote monitoring to diagnose bovine respiratory disease in beef calves.

PubMed

White, Brad J; Goehl, Dan R; Amrine, David E; Booker, Calvin; Wildman, Brian; Perrett, Tye

2016-04-01

Accurate diagnosis of bovine respiratory disease (BRD) in beef cattle is a critical facet of therapeutic programs through promotion of prompt treatment of diseased calves in concert with judicious use of antimicrobials. Despite the known inaccuracies, visual observation (VO) of clinical signs is the conventional diagnostic modality for BRD diagnosis. Objective methods of remotely monitoring cattle wellness could improve diagnostic accuracy; however, little information exists describing the accuracy of this method compared to traditional techniques. The objective of this research is to employ Bayesian methodology to elicit diagnostic characteristics of conventional VO compared to remote early disease identification (REDI) to diagnose BRD. Data from previous literature on the accuracy of VO were combined with trial data consisting of direct comparison between VO and REDI for BRD in two populations. No true gold standard diagnostic test exists for BRD; therefore, estimates of diagnostic characteristics of each test were generated using Bayesian latent class analysis. Results indicate a 90.0% probability that the sensitivity of REDI (median 81.3%; 95% probability interval [PI]: 55.5, 95.8) was higher than VO sensitivity (64.5%; PI: 57.9, 70.8). The specificity of REDI (median 92.9%; PI: 88.2, 96.9) was also higher compared to VO (median 69.1%; PI: 66.3, 71.8). The differences in sensitivity and specificity resulted in REDI exhibiting higher positive and negative predictive values in both high (41.3%) and low (2.6%) prevalence situations. This research illustrates the potential of remote cattle monitoring to augment conventional methods of BRD diagnosis resulting in more accurate identification of diseased cattle. Copyright © 2016 Elsevier B.V. All rights reserved.

A Panel of MicroRNAs as Diagnostic Biomarkers for the Identification of Prostate Cancer.

PubMed

Daniel, Rhonda; Wu, Qianni; Williams, Vernell; Clark, Gene; Guruli, Georgi; Zehner, Zendra

2017-06-16

Prostate cancer is the most common non-cutaneous cancer among men; yet, current diagnostic methods are insufficient, and more reliable diagnostic markers need to be developed. One answer that can bridge this gap may lie in microRNAs. These small RNA molecules impact protein expression at the translational level, regulating important cellular pathways, the dysregulation of which can exert tumorigenic effects contributing to cancer. In this study, high throughput sequencing of small RNAs extracted from blood from 28 prostate cancer patients at initial stages of diagnosis and prior to treatment was used to identify microRNAs that could be utilized as diagnostic biomarkers for prostate cancer compared to 12 healthy controls. In addition, a group of four microRNAs (miR-1468-3p, miR-146a-5p, miR-1538 and miR-197-3p) was identified as normalization standards for subsequent qRT-PCR confirmation. qRT-PCR analysis corroborated microRNA sequencing results for the seven top dysregulated microRNAs. The abundance of four microRNAs (miR-127-3p, miR-204-5p, miR-329-3p and miR-487b-3p) was upregulated in blood, whereas the levels of three microRNAs (miR-32-5p, miR-20a-5p and miR-454-3p) were downregulated. Data analysis of the receiver operating curves for these selected microRNAs exhibited a better correlation with prostate cancer than PSA (prostate-specific antigen), the current gold standard for prostate cancer detection. In summary, a panel of seven microRNAs is proposed, many of which have prostate-specific targets, which may represent a significant improvement over current testing methods.

Sensitivity and specificity of the amer dizziness diagnostic scale (adds) for patients with vestibular disorders.

PubMed

Al Saif, Amer; Alsenany, Samira

2015-01-01

[Purpose] To investigate the sensitivity and specificity of a newly developed diagnostic tool, the Amer Dizziness Diagnostic Scale (ADDS), to evaluate and differentially diagnose vestibular disorder and to identify the strengths and weaknesses of the scale and its usefulness in clinical practice. [Subjects and Methods] Two hundred subjects of both genders (72 males, 128 females) aged between 18 to 60 (49.5±7.8) who had a history of vertigo and/or dizziness symptoms for this previous two weeks or less were recruited for the study. All subjects were referred by otolaryngologists, neurologists or family physicians in and around Jeddah, Kingdom of Saudi Arabia. On the first clinic visit, all the patients were evaluated once using the ADDS, following which they underwent routine testing of clinical signs and symptoms, audiometry, and a neurological examination, coupled with tests of Vestibulo-Ocular Reflex function, which often serves as the "gold standard" for determining the probability of a vestibular deficit. [Results] The results show that the ADDS strongly correlated with "true-positive" and "true-negative" responses for determining the probability of a vestibular disorder (r =0.95). A stepwise linear regression was conducted and the results indicate that the ADDS was a significant predictor of "true-positive" and "true-negative" responses in vestibular disorders (R(2) =0.90). Approximately 90% of the variability in the vestibular gold standard test was explained by its relationship to the ADDS. Moreover, the ADDS was found to have a sensitivity of 96% and a specificity of 96%. [Conclusion] This study showed that the Amer Dizziness Diagnostic Scale has high sensitivity and specificity and that it can be used as a method of differential diagnosis for patients with vestibular disorders.

Patient-Centered Research

PubMed Central

Wicki, J; Perneger, TV; Junod, AF; Bounameaux, H; Perrier, A

2000-01-01

PURPOSE We aimed to develop a simple standardized clinical score to stratify emergency ward patients with clinically suspected PE into groups with a high, intermediate, or low probability of PE, in order to improve and simplify the diagnostic approach. METHODS Analysis of a database of 1090 consecutive patients admitted to the emergency ward for suspected PE, in whom diagnosis of PE was ruled in or out by a standard diagnostic algorithm. Logistic regression was used to predict clinical parameters associated with PE. RESULTS 296 out of 1090 patients (27%) were found to have PE. The optimal estimate of clinical probability was based on eight variables: recent surgery, previous thromboembolic event, older age, hypocapnia, hypoxemia, tachycardia, band atelectasis or elevation of a hemidiaphragm on chest X-ray. A probability score was calculated by adding points assigned to these variables. A cut-off score of 4 best identified patients with low probability of PE. 486 patients (49%) had a low clinical probability of PE (score < 4), of which 50 (10.3%) had a proven PE. The prevalence of PE was 38% in the 437 patients with an intermediate probability (score 5–8, n = 437) and 81% in the 63 patients with a high probability (score>9). CONCLUSION This clinical score, based on easily available and objective variables, provides a standardized assessment of the clinical probability of PE. Applying this score to emergency ward patients suspected of PE could allow a more efficient diagnostic process.

Proposed Diagnostic Criteria for Smartphone Addiction

PubMed Central

Lin, Yu-Hsuan; Chiang, Chih-Lin; Lin, Po-Hsien; Chang, Li-Ren; Ko, Chih-Hung; Lee, Yang-Han

2016-01-01

Background Global smartphone penetration has led to unprecedented addictive behaviors. The aims of this study are to develop diagnostic criteria of smartphone addiction and to examine the discriminative ability and the validity of the diagnostic criteria. Methods We developed twelve candidate criteria for characteristic symptoms of smartphone addiction and four criteria for functional impairment caused by excessive smartphone use. The participants consisted of 281 college students. Each participant was systematically assessed for smartphone-using behaviors by psychiatrist’s structured diagnostic interview. The sensitivity, specificity, and diagnostic accuracy of the candidate symptom criteria were analyzed with reference to the psychiatrists’ clinical global impression. The optimal model selection with its cutoff point of the diagnostic criteria differentiating the smartphone addicted subjects from non-addicted subjects was then determined by the best diagnostic accuracy. Results Six symptom criteria model with optimal cutoff point were determined based on the maximal diagnostic accuracy. The proposed smartphone addiction diagnostic criteria consisted of (1) six symptom criteria, (2) four functional impairment criteria and (3) exclusion criteria. Setting three symptom criteria as the cutoff point resulted in the highest diagnostic accuracy (84.3%), while the sensitivity and specificity were 79.4% and 87.5%, respectively. We suggested determining the functional impairment by two or more of the four domains considering the high accessibility and penetration of smartphone use. Conclusion The diagnostic criteria of smartphone addiction demonstrated the core symptoms “impaired control” paralleled with substance related and addictive disorders. The functional impairment involved multiple domains provide a strict standard for clinical assessment. PMID:27846211

Diagnostic Accuracy of Chinese Medicine Diagnosis Scale of Phlegm and Blood Stasis Syndrome in Coronary Heart Disease: A Study Protocol.

PubMed

Liu, Xiao-Qi; Peng, Dan-Hong; Wang, Yan-Ping; Xie, Rong; Chen, Xin-Lin; Yu, Chun-Quan; Li, Xian-Tao

2018-05-03

Phlegm and blood stasis syndrome (PBSS) is one of the main syndromes in coronary heart disease (CHD). Syndromes of Chinese medicine (CM) are lack of quantitative and easyimplementation diagnosis standards. To quantify and standardize the diagnosis of PBSS, scales are usually applied. To evaluate the diagnostic accuracy of CM diagnosis scale of PBSS in CHD. Six hundred patients with stable angina pectoris of CHD, 300 in case group and 300 in control group, will be recruited from 5 hospitals across China. Diagnosis from 2 experts will be considered as the "gold standard". The study design consists of 2 phases: pilot test is used to evaluate the reliability and validity, and diagnostic test is used to assess the diagnostic accuracy of the scale, including sensitivity, specififi city, likelihood ratio and area under the receiver operator characteristic (ROC) curve. This study will evaluate the diagnostic accuracy of CM diagnosis scale of PBSS in CHD. The consensus of 2 experts may not be ideal as a "gold standard", and itself still requires further study. (No. ChiCTR-OOC-15006599).

Working towards accreditation by the International Standards Organization 15189 Standard: how to validate an in-house developed method an example of lead determination in whole blood by electrothermal atomic absorption spectrometry.

PubMed

Garcia Hejl, Carine; Ramirez, Jose Manuel; Vest, Philippe; Chianea, Denis; Renard, Christophe

2014-09-01

Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.

Development of Conductive Polymer Analysis for the Rapid Detection and Identification of Phytopathogenic Microbes

Treesearch

A. Dan Wilson; D.G. Lester; C.S. Oberle

2004-01-01

Conductive polymer analysis, a type of electronic aroma detection technology, was evaluated for its efficacy in the detection, identification, and discrimination of plant-pathogenic microorganisms on standardized media and in diseased plant tissues. The method is based on the acquisition of a diagnostic electronic fingerprint derived from multisensor responses to...

Clinical applications of breath testing

PubMed Central

Paschke, Kelly M; Mashir, Alquam

2010-01-01

Breath testing has the potential to benefit the medical field as a cost-effective, non-invasive diagnostic tool for diseases of the lung and beyond. With growing evidence of clinical worth, standardization of methods, and new sensor and detection technologies the stage is set for breath testing to gain considerable attention and wider application in upcoming years. PMID:21173863

Prevalence Estimation and Validation of New Instruments in Psychiatric Research: An Application of Latent Class Analysis and Sensitivity Analysis

ERIC Educational Resources Information Center

Pence, Brian Wells; Miller, William C.; Gaynes, Bradley N.

2009-01-01

Prevalence and validation studies rely on imperfect reference standard (RS) diagnostic instruments that can bias prevalence and test characteristic estimates. The authors illustrate 2 methods to account for RS misclassification. Latent class analysis (LCA) combines information from multiple imperfect measures of an unmeasurable latent condition to…

Rapid and sensitive multiplex single-tube nested PCR for the identification of five human Plasmodium species.

PubMed

Saito, Takahiro; Kikuchi, Aoi; Kaneko, Akira; Isozumi, Rie; Teramoto, Isao; Kimura, Masatsugu; Hirasawa, Noriyasu; Hiratsuka, Masahiro

2018-06-01

Malaria is caused by five species of Plasmodium in humans. Microscopy is currently used for pathogen detection, requiring considerable training and technical expertise as the parasites are often difficult to differentiate morphologically. Rapid diagnostic tests are as reliable as microscopy and offer faster diagnoses but possess lower detection limits and are incapable of distinguishing among the parasitic species. To improve global health efforts towards malaria control, a rapid, sensitive, species-specific, and economically viable diagnostic method is needed. In this study, we designed a malaria diagnostic method involving a multiplex single-tube nested PCR targeting Plasmodium mitochondrial cytochrome c oxidase III and single-stranded tag hybridization chromatographic printed-array strip. The detection sensitivity was found to be at least 40 times higher than that of agarose gel electrophoresis with ethidium bromide. This system also enables the identification of both single- and mixed-species malaria infections. The assay was validated with 152 Kenyan samples; using nested PCR as the standard, the assay's sensitivity and specificity were 88.7% and 100.0%, respectively. The turnaround time required, from PCR preparation to signal detection, is 90min. Our method should improve the diagnostic speed, treatment efficacy, and control of malaria, in addition to facilitating surveillance within global malaria eradication programs. Copyright © 2018 Elsevier B.V. All rights reserved.

Advancing Diagnostics to Address Antibacterial Resistance: The Diagnostics and Devices Committee of the Antibacterial Resistance Leadership Group

PubMed Central

Tsalik, Ephraim L.; Petzold, Elizabeth; Kreiswirth, Barry N.; Bonomo, Robert A.; Banerjee, Ritu; Lautenbach, Ebbing; Evans, Scott R.; Hanson, Kimberly E.; Klausner, Jeffrey D.

2017-01-01

Abstract Diagnostics are a cornerstone of the practice of infectious diseases. However, various limitations frequently lead to unmet clinical needs. In most other domains, diagnostics focus on narrowly defined questions, provide readily interpretable answers, and use true gold standards for development. In contrast, infectious diseases diagnostics must contend with scores of potential pathogens, dozens of clinical syndromes, emerging pathogens, rapid evolution of existing pathogens and their associated resistance mechanisms, and the absence of gold standards in many situations. In spite of these challenges, the importance and value of diagnostics cannot be underestimated. Therefore, the Antibacterial Resistance Leadership Group has identified diagnostics as 1 of 4 major areas of emphasis. Herein, we provide an overview of that development, highlighting several examples where innovation in study design, content, and execution is advancing the field of infectious diseases diagnostics. PMID:28350903

Bayesian analysis of two diagnostic methods for paediatric ringworm infections in a teaching hospital.

PubMed

Rath, S; Panda, M; Sahu, M C; Padhy, R N

2015-09-01

Quantitatively, conventional methods of diagnosis of tinea capitis or paediatric ringworm, microscopic and culture tests were evaluated with Bayes rule. This analysis would help in quantifying the pervasive errors in each diagnostic method, particularly the microscopic method, as a long-term treatment would be involved to eradicate the infection by the use of a particular antifungal chemotherapy. Secondly, the analysis of clinical data would help in obtaining digitally the fallible standard of the microscopic test method, as the culture test method is taken as gold standard. Test results of 51 paediatric patients were of 4 categories: 21 samples were true positive (both tests positive), and 13 were true negative; the rest samples comprised both 14 false positive (microscopic test positivity with culture test negativity) and 3 false negative (microscopic test negativity with culture test positivity) samples. The prevalence of tinea infection was 47.01% in the population of 51 children. The microscopic test of a sample was efficient by 87.5%, in arriving at a positive result on diagnosis, when its culture test was positive; and, this test was efficient by 76.4%, in arriving at a negative result, when its culture test was negative. But, the post-test probability value of a sample with both microscopic and culture tests would be correct in distinguishing a sample from a sick or a healthy child with a chance of 71.5%. However, since the sensitivity of the analysis is 87.5%, the microscopic test positivity would be easier to detect in the presence of infection. In conclusion, it could be stated that Trychophyton rubrum was the most prevalent species; sensitivity and specificity of treating the infection, by antifungal therapy before ascertaining by the culture method remain as 0.8751 and 0.7642, respectively. A correct/coveted diagnostic method of fungal infection would be could be achieved by modern molecular methods (matrix-assisted laser desorption ionisation-time of flight mass spectrometry or fluorescence in situ hybridization or enzyme-linked immunosorbent assay [ELISA] or restriction fragment length polymorphism or DNA/RNA probes of known fungal taxa) in advanced laboratories. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Dilution testing using rapid diagnostic tests in a HIV diagnostic algorithm: a novel alternative for confirmation testing in resource limited settings.

PubMed

Shanks, Leslie; Siddiqui, M Ruby; Abebe, Almaz; Piriou, Erwan; Pearce, Neil; Ariti, Cono; Masiga, Johnson; Muluneh, Libsework; Wazome, Joseph; Ritmeijer, Koert; Klarkowski, Derryck

2015-05-14

Current WHO testing guidelines for resource limited settings diagnose HIV on the basis of screening tests without a confirmation test due to cost constraints. This leads to a potential risk of false positive HIV diagnosis. In this paper, we evaluate the dilution test, a novel method for confirmation testing, which is simple, rapid, and low cost. The principle of the dilution test is to alter the sensitivity of a rapid diagnostic test (RDT) by dilution of the sample, in order to screen out the cross reacting antibodies responsible for falsely positive RDT results. Participants were recruited from two testing centres in Ethiopia where a tiebreaker algorithm using 3 different RDTs in series is used to diagnose HIV. All samples positive on the initial screening RDT and every 10th negative sample underwent testing with the gold standard and dilution test. Dilution testing was performed using Determine™ rapid diagnostic test at 6 different dilutions. Results were compared to the gold standard of Western Blot; where Western Blot was indeterminate, PCR testing determined the final result. 2895 samples were recruited to the study. 247 were positive for a prevalence of 8.5 % (247/2895). A total of 495 samples underwent dilution testing. The RDT diagnostic algorithm misclassified 18 samples as positive. Dilution at the level of 1/160 was able to correctly identify all these 18 false positives, but at a cost of a single false negative result (sensitivity 99.6 %, 95 % CI 97.8-100; specificity 100 %, 95 % CI: 98.5-100). Concordance between the gold standard and the 1/160 dilution strength was 99.8 %. This study provides proof of concept for a new, low cost method of confirming HIV diagnosis in resource-limited settings. It has potential for use as a supplementary test in a confirmatory algorithm, whereby double positive RDT results undergo dilution testing, with positive results confirming HIV infection. Negative results require nucleic acid testing to rule out false negative results due to seroconversion or misclassification by the lower sensitivity dilution test. Further research is needed to determine if these results can be replicated in other settings. ClinicalTrials.gov, NCT01716299 .

Added diagnostic value of magnetoencephalography (MEG) in patients suspected for epilepsy, where previous, extensive EEG workup was unrevealing.

PubMed

Duez, Lene; Beniczky, Sándor; Tankisi, Hatice; Hansen, Peter Orm; Sidenius, Per; Sabers, Anne; Fuglsang-Frederiksen, Anders

2016-10-01

To elucidate the possible additional diagnostic yield of MEG in the workup of patients with suspected epilepsy, where repeated EEGs, including sleep-recordings failed to identify abnormalities. Fifty-two consecutive patients with clinical suspicion of epilepsy and at least three normal EEGs, including sleep-EEG, were prospectively analyzed. The reference standard was inferred from the diagnosis obtained from the medical charts, after at least one-year follow-up. MEG (306-channel, whole-head) and simultaneous EEG (MEG-EEG) was recorded for one hour. The added sensitivity of MEG was calculated from the cases where abnormalities were seen in MEG but not EEG. Twenty-two patients had the diagnosis epilepsy according to the reference standard. MEG-EEG detected abnormalities, and supported the diagnosis in nine of the 22 patients with the diagnosis epilepsy at one-year follow-up. Sensitivity of MEG-EEG was 41%. The added sensitivity of MEG was 18%. MEG-EEG was normal in 28 of the 30 patients categorized as 'not epilepsy' at one year follow-up, yielding a specificity of 93%. MEG provides additional diagnostic information in patients suspected for epilepsy, where repeated EEG recordings fail to demonstrate abnormality. MEG should be included in the diagnostic workup of patients where the conventional, widely available methods are unrevealing. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Simultaneous 11C-Methionine Positron Emission Tomography/Magnetic Resonance Imaging of Suspected Primary Brain Tumors

PubMed Central

Deuschl, Cornelius; Goericke, Sophia; Grueneisen, Johannes; Sawicki, Lino Morris; Goebel, Juliane; El Hindy, Nicolai; Wrede, Karsten; Binse, Ina; Poeppel, Thorsten; Quick, Harald; Forsting, Michael; Hense, Joerg; Umutlu, Lale; Schlamann, Marc

2016-01-01

Introduction The objective of this study was to assess the diagnostic value of integrated 11C- methionine PET/MRI for suspected primary brain tumors, in comparison to MRI alone. Material and Methods Forty-eight consecutive patients with suspected primary brain tumor were prospectively enrolled for an integrated 11C-methionine PET/MRI. Two neuro-radiologists separately evaluated the MRI alone and the integrated PET/MRI data sets regarding most likely diagnosis and diagnostic confidence on a 5-point scale. Reference standard was histopathology or follow-up imaging. Results Fifty-one suspicious lesions were detected: 16 high-grade glioma and 25 low-grade glioma. Ten non-malignant cerebral lesions were described by the reference standard. MRI alone and integrated PET/MRI each correctly classified 42 of the 51 lesions (82.4%) as neoplastic lesions (WHO grade II, III and IV) or non-malignant lesions (infectious and neoplastic lesions). Diagnostic confidence for all lesions, low-grade astrocytoma and high-grade astrocytoma (3.7 vs. 4.2, 3,1 vs. 3.8, 4.0 vs. 4,7) were significantly (p < 0.05) better with integrated PET/MRI than in MRI alone. Conclusions The present study demonstrates the high potential of integrated 11C-methionine-PET/MRI for the assessment of suspected primary brain tumors. Although integrated methionine PET/MRI does not lead to an improvement of correct diagnoses, diagnostic confidence is significantly improved. PMID:27907162

Improved diagnostic yield compared with targeted gene sequencing panels suggests a role for whole-genome sequencing as a first-tier genetic test

PubMed Central

Lionel, Anath C; Costain, Gregory; Monfared, Nasim; Walker, Susan; Reuter, Miriam S; Hosseini, S Mohsen; Thiruvahindrapuram, Bhooma; Merico, Daniele; Jobling, Rebekah; Nalpathamkalam, Thomas; Pellecchia, Giovanna; Sung, Wilson W L; Wang, Zhuozhi; Bikangaga, Peter; Boelman, Cyrus; Carter, Melissa T; Cordeiro, Dawn; Cytrynbaum, Cheryl; Dell, Sharon D; Dhir, Priya; Dowling, James J; Heon, Elise; Hewson, Stacy; Hiraki, Linda; Inbar-Feigenberg, Michal; Klatt, Regan; Kronick, Jonathan; Laxer, Ronald M; Licht, Christoph; MacDonald, Heather; Mercimek-Andrews, Saadet; Mendoza-Londono, Roberto; Piscione, Tino; Schneider, Rayfel; Schulze, Andreas; Silverman, Earl; Siriwardena, Komudi; Snead, O Carter; Sondheimer, Neal; Sutherland, Joanne; Vincent, Ajoy; Wasserman, Jonathan D; Weksberg, Rosanna; Shuman, Cheryl; Carew, Chris; Szego, Michael J; Hayeems, Robin Z; Basran, Raveen; Stavropoulos, Dimitri J; Ray, Peter N; Bowdin, Sarah; Meyn, M Stephen; Cohn, Ronald D; Scherer, Stephen W; Marshall, Christian R

2018-01-01

Purpose Genetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use. Methods We prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing. Results WGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24% P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A. Conclusion WGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort. PMID:28771251

Improved diagnostic yield compared with targeted gene sequencing panels suggests a role for whole-genome sequencing as a first-tier genetic test.

PubMed

Lionel, Anath C; Costain, Gregory; Monfared, Nasim; Walker, Susan; Reuter, Miriam S; Hosseini, S Mohsen; Thiruvahindrapuram, Bhooma; Merico, Daniele; Jobling, Rebekah; Nalpathamkalam, Thomas; Pellecchia, Giovanna; Sung, Wilson W L; Wang, Zhuozhi; Bikangaga, Peter; Boelman, Cyrus; Carter, Melissa T; Cordeiro, Dawn; Cytrynbaum, Cheryl; Dell, Sharon D; Dhir, Priya; Dowling, James J; Heon, Elise; Hewson, Stacy; Hiraki, Linda; Inbar-Feigenberg, Michal; Klatt, Regan; Kronick, Jonathan; Laxer, Ronald M; Licht, Christoph; MacDonald, Heather; Mercimek-Andrews, Saadet; Mendoza-Londono, Roberto; Piscione, Tino; Schneider, Rayfel; Schulze, Andreas; Silverman, Earl; Siriwardena, Komudi; Snead, O Carter; Sondheimer, Neal; Sutherland, Joanne; Vincent, Ajoy; Wasserman, Jonathan D; Weksberg, Rosanna; Shuman, Cheryl; Carew, Chris; Szego, Michael J; Hayeems, Robin Z; Basran, Raveen; Stavropoulos, Dimitri J; Ray, Peter N; Bowdin, Sarah; Meyn, M Stephen; Cohn, Ronald D; Scherer, Stephen W; Marshall, Christian R

2018-04-01

PurposeGenetic testing is an integral diagnostic component of pediatric medicine. Standard of care is often a time-consuming stepwise approach involving chromosomal microarray analysis and targeted gene sequencing panels, which can be costly and inconclusive. Whole-genome sequencing (WGS) provides a comprehensive testing platform that has the potential to streamline genetic assessments, but there are limited comparative data to guide its clinical use.MethodsWe prospectively recruited 103 patients from pediatric non-genetic subspecialty clinics, each with a clinical phenotype suggestive of an underlying genetic disorder, and compared the diagnostic yield and coverage of WGS with those of conventional genetic testing.ResultsWGS identified diagnostic variants in 41% of individuals, representing a significant increase over conventional testing results (24%; P = 0.01). Genes clinically sequenced in the cohort (n = 1,226) were well covered by WGS, with a median exonic coverage of 40 × ±8 × (mean ±SD). All the molecular diagnoses made by conventional methods were captured by WGS. The 18 new diagnoses made with WGS included structural and non-exonic sequence variants not detectable with whole-exome sequencing, and confirmed recent disease associations with the genes PIGG, RNU4ATAC, TRIO, and UNC13A.ConclusionWGS as a primary clinical test provided a higher diagnostic yield than conventional genetic testing in a clinically heterogeneous cohort.

A Statistical Evaluation of the Diagnostic Performance of MEDAS-The Medical Emergency Decision Assistance System

PubMed Central

Georgakis, D. Christine; Trace, David A.; Naeymi-Rad, Frank; Evens, Martha

1990-01-01

Medical expert systems require comprehensive evaluation of their diagnostic accuracy. The usefulness of these systems is limited without established evaluation methods. We propose a new methodology for evaluating the diagnostic accuracy and the predictive capacity of a medical expert system. We have adapted to the medical domain measures that have been used in the social sciences to examine the performance of human experts in the decision making process. Thus, in addition to the standard summary measures, we use measures of agreement and disagreement, and Goodman and Kruskal's λ and τ measures of predictive association. This methodology is illustrated by a detailed retrospective evaluation of the diagnostic accuracy of the MEDAS system. In a study using 270 patients admitted to the North Chicago Veterans Administration Hospital, diagnoses produced by MEDAS are compared with the discharge diagnoses of the attending physicians. The results of the analysis confirm the high diagnostic accuracy and predictive capacity of the MEDAS system. Overall, the agreement of the MEDAS system with the “gold standard” diagnosis of the attending physician has reached a 90% level.

Advanced imaging techniques for small bowel Crohn's disease: what does the future hold?

PubMed

Pita, Inês; Magro, Fernando

2018-01-01

Treatment of Crohn's disease (CD) is intrinsically reliant on imaging techniques, due to the preponderance of small bowel disease and its transmural pattern of inflammation. Ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) are the most widely employed imaging methods and have excellent diagnostic accuracy in most instances. Some limitations persist, perhaps the most clinically relevant being the distinction between inflammatory and fibrotic strictures. In this regard, several methodologies have recently been tested in animal models and human patients, namely US strain elastography, shear wave elastography, contrast-enhanced US, magnetization transfer MRI and contrast dynamics in standard MRI. Technical advances in each of the imaging methods may expand their indications. The addition of oral contrast to abdominal US appears to substantially improve its diagnostic capabilities compared to standard US. Ionizing dose-reduction methods in CT can decrease concern about cumulative radiation exposure in CD patients and diffusion-weighted MRI may reduce the need for gadolinium contrast. Clinical indexes of disease activity and severity are also increasingly relying on imaging scores, such as the recently developed Lémann Index. In this review we summarize some of the recent advances in small bowel CD imaging and how they might affect clinical practice in the near future.

The Global Neurological Burden of Tuberculosis.

PubMed

Thakur, Kiran; Das, Mitashee; Dooley, Kelly E; Gupta, Amita

2018-04-01

Central nervous system (CNS) involvement of tuberculosis (TB) is the most severe manifestation of TB and accounts for approximately 5 to 10% of all extrapulmonary TB (EPTB) cases and approximately 1% of all TB cases. TB meningitis (TBM) is the most common form of CNS TB, though other forms occur, often in conjunction with TBM, including intracranial tuberculomas, tuberculous brain abscesses, and spinal tubercular arachnoiditis. CNS TB often presents with nonspecific clinical features that mimic symptoms of other neurological conditions, often making diagnosis difficult. Defining neuroimaging characteristics of TBM include thick basal meningeal enhancement, hydrocephalus, and parenchymal infarctions most commonly involving the basal ganglia and internal capsule. Traditional cerebrospinal fluid sample analysis frequently requires lengthy times-to-result and have low sensitivity. Given the pitfalls of conventional CNS TB diagnostic methods, various molecular-based methods, including immunoassays and polymerase chain reaction (PCR)-based assays have emerged as alternative diagnostic tools due to their rapidity, sensitivity, and specificity. Expert panels on TBM have recently emphasized the need for standard research procedures with updated case definitions and standardized study methods, which will hopefully pave the way for more robust multicenter international studies. In this article, we review the epidemiology, diagnosis, molecular factors associated with disease presentation and outcome, and treatment of CNS TB. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Capillary whole blood testing by a new portable monitor. Comparison with standard determination of the international normalized ratio.

PubMed

de Miguel, Dunia; Burgaleta, Carmen; Reyes, Eduardo; Pascual, Teresa

2003-07-01

We evaluated a new portable monitor (AvoSure PT PRO, Menarini Diagnostics, Firenze, Italy) developed to test the prothrombin time in capillary blood and plasma by comparing it with the standard laboratory determination. We studied 62 patients receiving acenocoumarol therapy. The international normalized ratio (INR) in capillary blood was analyzed by 2 methods: AvoSure PT PRO and Thrombotrack Nycomed Analyzer (Axis-Shield, Dundee, Scotland). Parallel studies were performed in plasma samples by a reference method using the Behring Coagulation Timer (Behring Diagnostics, Marburg, Germany). Plasma samples also were tested with the AvoSure PT PRO. Correlation was good for INR values for capillary blood and plasma samples by AvoSure PT PRO and our reference method (R2 = 0.8596) and for capillary blood samples tested by the AvoSure PT PRO and Thrombotrack Nycomed Analyzer (R2 = 0.8875). The correlation for INR in capillary blood and plasma samples by AvoSure PT PRO was 0.6939 (P < .0004). Capillary blood determinations are rapid and effective for monitoring oral anticoagulation therapy and have a high correlation to plasma determinations. AvoSure PT PRO is accurate for controlling INR in plasma and capillary blood samples, may be used in outpatient clinics, and has advantages over previous portable monitors.

Machine learning classification with confidence: application of transductive conformal predictors to MRI-based diagnostic and prognostic markers in depression.

PubMed

Nouretdinov, Ilia; Costafreda, Sergi G; Gammerman, Alexander; Chervonenkis, Alexey; Vovk, Vladimir; Vapnik, Vladimir; Fu, Cynthia H Y

2011-05-15

There is rapidly accumulating evidence that the application of machine learning classification to neuroimaging measurements may be valuable for the development of diagnostic and prognostic prediction tools in psychiatry. However, current methods do not produce a measure of the reliability of the predictions. Knowing the risk of the error associated with a given prediction is essential for the development of neuroimaging-based clinical tools. We propose a general probabilistic classification method to produce measures of confidence for magnetic resonance imaging (MRI) data. We describe the application of transductive conformal predictor (TCP) to MRI images. TCP generates the most likely prediction and a valid measure of confidence, as well as the set of all possible predictions for a given confidence level. We present the theoretical motivation for TCP, and we have applied TCP to structural and functional MRI data in patients and healthy controls to investigate diagnostic and prognostic prediction in depression. We verify that TCP predictions are as accurate as those obtained with more standard machine learning methods, such as support vector machine, while providing the additional benefit of a valid measure of confidence for each prediction. Copyright © 2010 Elsevier Inc. All rights reserved.

Diagnostic imaging of the nasolacrimal drainage system. Part I. Radiological anatomy of lacrimal pathways. Physiology of tear secretion and tear outflow.

PubMed

Maliborski, Artur; Różycki, Radosław

2014-04-17

Excessive watering of the eye is a common condition in ophthalmological practice. It may be the result of excessive production of tear fluid or obstruction and insufficiency of efferent tear pathways. The differentiation between obstruction and insufficiency of the lacrimal pathways is still clinically questionable. In the diagnostic process it is necessary to perform clinical tests and additional diagnostic imaging is often needed. Dacryocystography, with or without the extension of the dynamic phase or subtraction option, still remains the criterion standard for diagnostic imaging of the lacrimal obstruction. It may help to clarify the cause and exact place of the obstruction and provide information for further management, especially surgical treatment. Increasingly, new techniques are used in diagnostic imaging of the lacrimal tract, such as computed tomography, magnetic resonance, and isotopic methods. Adequate knowledge of the anatomy and physiology of the lacrimal system and the secretion and outflow of tears is the basis for proper diagnostic imaging. The purpose of this paper is to present the exact anatomy of the lacrimal system, with particular emphasis on the radiological anatomy and the current state of knowledge about the physiology of tear secretion and drainage.

Impact of iterative metal artifact reduction on diagnostic image quality in patients with dental hardware.

PubMed

Weiß, Jakob; Schabel, Christoph; Bongers, Malte; Raupach, Rainer; Clasen, Stephan; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

2017-03-01

Background Metal artifacts often impair diagnostic accuracy in computed tomography (CT) imaging. Therefore, effective and workflow implemented metal artifact reduction algorithms are crucial to gain higher diagnostic image quality in patients with metallic hardware. Purpose To assess the clinical performance of a novel iterative metal artifact reduction (iMAR) algorithm for CT in patients with dental fillings. Material and Methods Thirty consecutive patients scheduled for CT imaging and dental fillings were included in the analysis. All patients underwent CT imaging using a second generation dual-source CT scanner (120 kV single-energy; 100/Sn140 kV in dual-energy, 219 mAs, gantry rotation time 0.28-1/s, collimation 0.6 mm) as part of their clinical work-up. Post-processing included standard kernel (B49) and an iterative MAR algorithm. Image quality and diagnostic value were assessed qualitatively (Likert scale) and quantitatively (HU ± SD) by two reviewers independently. Results All 30 patients were included in the analysis, with equal reconstruction times for iMAR and standard reconstruction (17 s ± 0.5 vs. 19 s ± 0.5; P > 0.05). Visual image quality was significantly higher for iMAR as compared with standard reconstruction (3.8 ± 0.5 vs. 2.6 ± 0.5; P < 0.0001, respectively) and showed improved evaluation of adjacent anatomical structures. Similarly, HU-based measurements of degree of artifacts were significantly lower in the iMAR reconstructions as compared with the standard reconstruction (0.9 ± 1.6 vs. -20 ± 47; P < 0.05, respectively). Conclusion The tested iterative, raw-data based reconstruction MAR algorithm allows for a significant reduction of metal artifacts and improved evaluation of adjacent anatomical structures in the head and neck area in patients with dental hardware.

Connected car: Engines diagnostic via Internet of Things (IoT)

NASA Astrophysics Data System (ADS)

Hamid, A. F. A.; Rahman, M. T. A.; Khan, S. F.; Adom, A. H.; Rahim, M. A.; Rahim, N. A.; Ismail, M. H. N.; Norizan, A.

2017-10-01

This paper is about an experiment for performing engines diagnostic using wireless sensing Internet of Thing (IoT). The study is to overcome problem of current standard On Board Diagnosis (OBD-II) data acquisition method that only can be perform in offline or wired method. From this paper it show a method to determined how the data from engines can be collected, make the data can be easily understand by human and sending data over the wireless internet connection via platform of IOT. This study is separate into three stages that is CAN-bus data collection, CAN data conversion and send data to cloud storage. Every stage is experimented with a two different method and consist five data parameter that is Revolution per Minute (RPM), Manifold Air Pressure (MAP), load-fuel, barometric pressure and engine temperature. The experiment use Arduino Uno as microcontroller, CAN-bus converter and ESP8266 wifi board as transfer medium for data to internet.

DETERMINATION OF NATIONAL DIAGNOSTIC REFERENCE LEVELS IN COMPUTED TOMOGRAPHY EXAMINATIONS OF IRAN BY A NEW QUALITY CONTROL-BASED DOSE SURVEY METHOD.

PubMed

Sohrabi, Mehdi; Parsi, Masoumeh; Mianji, Fereidoun

2018-05-01

National diagnostic reference levels (NDRLs) of Iran were determined for the four most common CT examinations including head, sinus, chest and abdomen/pelvis. A new 'quality control (QC)-based dose survey method', as developed by us, was applied to 157 CT scanners in Iran (2014-15) with different slice classes, models and geographic spread across the country. The NDRLs for head, sinus, chest and abdomen/pelvis examinations are 58, 29, 12 and 14 mGy for CTDIVol and 750, 300, 300 and 650 mGy.cm for DLP, respectively. The 'QC-based dose survey method' was further proven that it is a simple, accurate and practical method for a time and cost-effective NDRLs determination. One effective approach for optimization of the CT examination protocols at the national level is the provision of an adequate standardized training of the radiologists, technicians and medical physicists on the patient radiation protection principles and implementation of the DRL concept in clinical practices.

Towards Modernizing the Characterization of Shock and Detonation Physics Performance via Novel Diagnostics and Tests

NASA Astrophysics Data System (ADS)

Salyer, Terry

2017-06-01

For the bulk of detonation performance experiments, a fairly basic set of diagnostic techniques has evolved as the standard for acquiring the necessary measurements. Gold standard techniques such as pin switches and streak cameras still produce the high-quality data required, yet much room remains for improvement with regard to ease of use, cost of fielding, breadth of data, and diagnostic versatility. Over the past several years, an alternate set of diagnostics has been under development to replace many of these traditional techniques. Pulse Correlation Reflectometry (PCR) is a capable substitute for pin switches with the advantage of obtaining orders of magnitude more data at a small fraction of the cost and fielding time. Spectrally Encoded Imaging (SEI) can replace most applications of streak camera with the advantage of imaging surfaces through a single optical fiber that are otherwise optically inaccessible. Such diagnostics advance the measurement state of the art, but even further improvements may come through revamping the standardized tests themselves such as the copper cylinder expansion test. At the core of this modernization, the aforementioned diagnostics play a significant role in revamping and improving the standard test suite for the present era. This research was performed under the auspices of the United States Department of Energy.

Improved diagnostics of chronic inflammatory prostatitis.

PubMed

Kulchavenya, E; Azizoff, A; Brizhatyuk, E; Khomyakov, V; Kholtobin, D; Breusoff, A; Naber, K G

2012-12-01

Prostatitis is a prevalent condition that encompasses a large array of clinical symptoms with significant impacts on men's life. The diagnosis and treatment of this disorder presents numerous challenges for urologists, most notably, a lack of specific and effective diagnostic methods. To improve the diagnostics the comparison of classic 4-glass test Meares and Stamey, 2-glass tests and 3-glass test was conducted in 177 men suspicious for chronic prostatitis. Four-glass test is uncomfortable both for patients and doctors, and leads to contamination of urine with prostatic secretion. Two-glass test is insufficiently effective too. Three-glass test (three urine specimens obtained from one continuous micturition stream) gives more adequate results and may be used for screening. Three-glass test as screening test with the option of an additional EPS investigation in those patients the final diagnosis of chronic prostatitis has to be confirmed is more convenient for patients and doctors than the standard M&S 4-glass test and "false-positive" (contaminated with EPS) midstream urine results are avoided thus improving discrimination of urethritis, cystitis and prostatitis. Therefore, we recommend the KE 3-glass test as a new standard for screening patients with signs and symptoms of chronic inflammatory prostatitis.

Quantitative diagnostic method for biceps long head tendinitis by using ultrasound.

PubMed

Huang, Shih-Wei; Wang, Wei-Te

2013-01-01

To investigate the feasibility of grayscale quantitative diagnostic method for biceps tendinitis and determine the cut-off points of a quantitative biceps ultrasound (US) method to diagnose biceps tendinitis. Design. Prospective cross-sectional case controlled study. Outpatient rehabilitation service. A total of 336 shoulder pain patients with suspected biceps tendinitis were recruited in this prospective observational study. The grayscale pixel data of the range of interest (ROI) were obtained for both the transverse and longitudinal views of the biceps US. A total of 136 patients were classified with biceps tendinitis, and 200 patients were classified as not having biceps tendinitis based on the diagnostic criteria. Based on the Youden index, the cut-off points were determined as 26.85 for the transverse view and 21.25 for the longitudinal view of the standard deviation (StdDev) of the ROI values, respectively. When the ROI evaluation of the US surpassed the cut-off point, the sensitivity was 68% and the specificity was 90% in the StdDev of the transverse view, and the sensitivity was 81% and the specificity was 73% in the StdDev of the longitudinal view to diagnose biceps tendinitis. For equivocal cases or inexperienced sonographers, our study provides a more objective method for diagnosing biceps tendinitis in shoulder pain patients.

White-Nose Syndrome Disease Severity and a Comparison of Diagnostic Methods.

PubMed

McGuire, Liam P; Turner, James M; Warnecke, Lisa; McGregor, Glenna; Bollinger, Trent K; Misra, Vikram; Foster, Jeffrey T; Frick, Winifred F; Kilpatrick, A Marm; Willis, Craig K R

2016-03-01

White-nose syndrome is caused by the fungus Pseudogymnoascus destructans and has killed millions of hibernating bats in North America but the pathophysiology of the disease remains poorly understood. Our objectives were to (1) assess non-destructive diagnostic methods for P. destructans infection compared to histopathology, the current gold-standard, and (2) to evaluate potential metrics of disease severity. We used data from three captive inoculation experiments involving 181 little brown bats (Myotis lucifugus) to compare histopathology, quantitative PCR (qPCR), and ultraviolet fluorescence as diagnostic methods of P. destructans infection. To assess disease severity, we considered two histology metrics (wing area with fungal hyphae, area of dermal necrosis), P. destructans fungal load (qPCR), ultraviolet fluorescence, and blood chemistry (hematocrit, sodium, glucose, pCO2, and bicarbonate). Quantitative PCR was most effective for early detection of P. destructans, while all three methods were comparable in severe infections. Correlations among hyphae and necrosis scores, qPCR, ultraviolet fluorescence, blood chemistry, and hibernation duration indicate a multi-stage pattern of disease. Disruptions of homeostasis occurred rapidly in late hibernation. Our results provide valuable information about the use of non-destructive techniques for monitoring, and provide novel insight into the pathophysiology of white-nose syndrome, with implications for developing and implementing potential mitigation strategies.

The use of biomarkers and molecular methods for the earlier diagnosis of invasive aspergillosis in immunocompromised patients.

PubMed

Ambasta, Anshula; Carson, Julie; Church, Deirdre L

2015-08-01

Invasive aspergillosis (IA) is an opportunistic infection that is often life threatening in the immunocompromised host. Early diagnosis is critical, especially given the efficacy and availability of several new anti-fungal therapies. Current (2008) diagnostic criteria have limited ability to detect early infection and are aimed at establishing disease. Although histopathology and culture techniques have traditionally been used to make a proven diagnosis of IA, their dependence on tissue samples and slow turnaround times hamper early confirmation of IA. Serologic detection of circulating galactomannan and 1,3-β-D-glucan fungal biomarkers show promise for improving the diagnosis of IA, and their use is included in the EORTC/MSG diagnostic criteria for IA. Numerous studies have evaluated the diagnostic performance of these two biomarkers and shown that they have suboptimal sensitivity when used alone for early diagnosis of proven IA. Currently available molecular assays also suffer from a lack of standardization. Evaluation of the use of different combinations of test methods to enhance diagnostic accuracy is also being done but prompt, accurate diagnosis of IA remains a clinical and diagnostic challenge. The clinical validity and limitations of biomarkers and current molecular methods for the early diagnosis of IA are summarized in this review with respect to the different patient populations at risk for this serious infection. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Do Practical Standard Coupled Cluster Calculations Agree Better than Kohn–Sham Calculations with Currently Available Functionals When Compared to the Best Available Experimental Data for Dissociation Energies of Bonds to 3d Transition Metals?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Xuefei; Zhang, Wenjing; Tang, Mingsheng

2015-05-12

Coupled-cluster (CC) methods have been extensively used as the high-level approach in quantum electronic structure theory to predict various properties of molecules when experimental results are unavailable. It is often assumed that CC methods, if they include at least up to connected-triple-excitation quasiperturbative corrections to a full treatment of single and double excitations (in particular, CCSD(T)), and a very large basis set, are more accurate than Kohn–Sham (KS) density functional theory (DFT). In the present work, we tested and compared the performance of standard CC and KS methods on bond energy calculations of 20 3d transition metal-containing diatomic molecules againstmore » the most reliable experimental data available, as collected in a database called 3dMLBE20. It is found that, although the CCSD(T) and higher levels CC methods have mean unsigned deviations from experiment that are smaller than most exchange-correlation functionals for metal–ligand bond energies of transition metals, the improvement is less than one standard deviation of the mean unsigned deviation. Furthermore, on average, almost half of the 42 exchange-correlation functionals that we tested are closer to experiment than CCSD(T) with the same extended basis set for the same molecule. The results show that, when both relativistic and core–valence correlation effects are considered, even the very high-level (expensive) CC method with single, double, triple, and perturbative quadruple cluster operators, namely, CCSDT(2)Q, averaged over 20 bond energies, gives a mean unsigned deviation (MUD(20) = 4.7 kcal/mol when one correlates only valence, 3p, and 3s electrons of transition metals and only valence electrons of ligands, or 4.6 kcal/mol when one correlates all core electrons except for 1s shells of transition metals, S, and Cl); and that is similar to some good xc functionals (e.g., B97-1 (MUD(20) = 4.5 kcal/mol) and PW6B95 (MUD(20) = 4.9 kcal/mol)) when the same basis set is used. We found that, for both coupled cluster calculations and KS calculations, the T1 diagnostics correlate the errors better than either the M diagnostics or the B1 DFT-based diagnostics. The potential use of practical standard CC methods as a benchmark theory is further confounded by the finding that CC and DFT methods usually have different signs of the error. We conclude that the available experimental data do not provide a justification for using conventional single-reference CC theory calculations to validate or test xc functionals for systems involving 3d transition metals.« less

[Medicolegal aspects of child abuse].

PubMed

Hofer, P; Brandau, L-M; Mützel, E

2016-05-01

The prevention and clinical diagnostics of maltreatment of children and adolescents represents a great challenge to all medical disciplines concerned; therefore, an interdisciplinary collaboration is indispensable. Medicolegal experts require specific radiological examination methods for the differentiation between accidental and non-accidental injuries, depending on the corresponding point in question. In addition, a clear and structured radiological appraisal of the findings is necessary. On the other hand, radiologists require an appropriate succinctly phrased question from the medicolegal expert. A close collaboration between radiologists and medicolegal experts is mandatory for a better recognition of cases of child abuse; therefore, the joint establishment of diagnostic standards and a comprehensive implementation is necessary.

The Astronomy Diagnostic Test: Comparing Your Class to Others

NASA Astrophysics Data System (ADS)

Hufnagel, B.; Deming, G.

1999-05-01

A standard diagnostic test can be a powerful tool to assess the conceptual understanding of students, as has been proven for undergraduate physics instruction over the last ten years (e.g., E.F. Redish and R.N. Steinberg 1999, Physics Today, 52:1, 24). If you are now using, or are considering adopting, a more interactive teaching style such as that used by Eric Mazur (Peer Instruction: a User's Manual, [Prentice-Hall: 1997]) or Michael Zeilik and his collaborators (1997, AJP, 65:12, 987), you may want to use a standard diagnostic test designed for undergraduate astronomy classes. Details of the validation of the ADT are at Slater et al., also presented in this session. A comparative database of ADT scores, by class and by question, can help the instructor assess student preparedness and the effectiveness of alternative teaching methods. In the spring of 1999, 19 astronomy instructors at 7 state universities, 4 community colleges, 4 liberal arts schools, 1 woman's college and 1 technical university across the USA gave the ADT to their classes once at the beginning of the course, and again at the end of the course. The average pre-course ADT scores by class from these ~ 1000 students show two surprising results: the conceptual understanding of introductory classes is about the same (34%) regardless of type of school, geographic location, or average student age. However, there is a significant gender difference, with females scoring an average of 29% and males 39%, with the standard errors both less than 1%. The Astronomy Diagnostic Test (ADT) and its comparative by-class database will be available at the National Institute for Science Education (NISE) website after 1 June 1999. This research was supported by the National Science Foundation through Grant DGE-9714489, and by the generosity of the participating astronomy instructors.

[Clinical implications of dual-energy computed tomography in the diagnosis and treatment of urolithiasis].

PubMed

Kapanadze, L B; Ternovoy, S K; Rudenko, V I; Serova, N S

2018-03-01

Urolithiasis (urolithiasis) is one of the most common urologic diseases with an estimated prevalence of no less than 3% in the population, usually affecting active working-age patients of 30-50 years. Taking into account major public health and economic significance of this problem, there is the need for the development of effective modern diagnostic techniques. Rapid medical-technological advances of the past two decades have led to the wide spread use of minimally invasive surgery the management of urolithiasis. Nevertheless, surgical intervention only removes the result of a long pathological process and does not change its course. Thus, there is a need for a detailed understanding of the etiology, epidemiology, and pathogenesis of urolithiasis. Diagnostic imaging plays a key role in the diagnosis of urolithiasis. Multislice spiral computed tomography (MSCT) is the gold standard for the diagnosis of urolithiasis. It provides information about the size, location, and density of the calculus. Over the past decade, the use of dual-energy computed tomography (DECT) in urological practice has been widely discussed in the international and domestic literature. One of the main advantages of DECT is the ability to determine the chemical composition of urinary stones. Previous studies have reported a high diagnostic value of the method, including the ability to predict treatment outcomes. However, the shortcomings of the method and the absence of standardized examination protocols leave a wide field for further research. This article reviews major distinctive features of using DECT in the diagnosis of urolithiasis.

Identifying species of moths (Lepidoptera) from Baihua Mountain, Beijing, China, using DNA barcodes

PubMed Central

Liu, Xiao F; Yang, Cong H; Han, Hui L; Ward, Robert D; Zhang, Ai-bing

2014-01-01

DNA barcoding has become a promising means for the identification of organisms of all life-history stages. Currently, distance-based and tree-based methods are most widely used to define species boundaries and uncover cryptic species. However, there is no universal threshold of genetic distance values that can be used to distinguish taxonomic groups. Alternatively, DNA barcoding can deploy a “character-based” method, whereby species are identified through the discrete nucleotide substitutions. Our research focuses on the delimitation of moth species using DNA-barcoding methods. We analyzed 393 Lepidopteran specimens belonging to 80 morphologically recognized species with a standard cytochrome c oxidase subunit I (COI) sequencing approach, and deployed tree-based, distance-based, and diagnostic character-based methods to identify the taxa. The tree-based method divided the 393 specimens into 79 taxa (species), and the distance-based method divided them into 84 taxa (species). Although the diagnostic character-based method found only 39 so-identifiable species in the 80 species, with a reduction in sample size the accuracy rate substantially improved. For example, in the Arctiidae subset, all 12 species had diagnostics characteristics. Compared with traditional morphological method, molecular taxonomy performed well. All three methods enable the rapid delimitation of species, although they have different characteristics and different strengths. The tree-based and distance-based methods can be used for accurate species identification and biodiversity studies in large data sets, while the character-based method performs well in small data sets and can also be used as the foundation of species-specific biochips. PMID:25360280

Detection of scabies: A systematic review of diagnostic methods.

PubMed

Leung, Victor; Miller, Mark

2011-01-01

Accurate diagnosis of scabies infection is important for patient treatment and for public health control of scabies epidemics. To systematically review the accuracy and precision of history, physical examination and tests for diagnosing scabies. Using a structured search strategy, Medline and Embase databases were searched for English and French language articles that included a diagnosis of scabies. Studies comparing history, physical examination and/or any diagnostic tests with the reference standard of microscopic visualization of mites, eggs or fecal elements obtained from skin scrapings or biopsies were included for analysis. Data were extracted using standard criteria. History and examination of pruritic dermatoses failed to accurately diagnose scabies infection. Dermatoscopy by a trained practitioner has a positive likelihood ratio of 6.5 (95% CI 4.1 to 10.3) and a negative likelihood ratio of 0.1 (95% CI 0.06 to 0.2) for diagnosing scabies. The accuracy of other diagnostic tests could not be calculated from the data in the literature. In the face of such diagnostic inaccuracy, clinical judgment is still practical in diagnosing scabies. Two tests are used - the burrow ink test and handheld dermatoscopy. The burrow ink test is a simple, rapid, noninvasive test that can be used to screen a large number of patients. Handheld dermatoscopy is an accurate test, but requires special equipment and trained practitioners. Given the morbidity and costs of scabies infection, and that studies to date lack adequate internal and external validity, research to identify or develop accurate diagnostic tests for scabies infection is needed and justifiable.

Identifying and quantifying heterogeneity in high content analysis: application of heterogeneity indices to drug discovery.

PubMed

Gough, Albert H; Chen, Ning; Shun, Tong Ying; Lezon, Timothy R; Boltz, Robert C; Reese, Celeste E; Wagner, Jacob; Vernetti, Lawrence A; Grandis, Jennifer R; Lee, Adrian V; Stern, Andrew M; Schurdak, Mark E; Taylor, D Lansing

2014-01-01

One of the greatest challenges in biomedical research, drug discovery and diagnostics is understanding how seemingly identical cells can respond differently to perturbagens including drugs for disease treatment. Although heterogeneity has become an accepted characteristic of a population of cells, in drug discovery it is not routinely evaluated or reported. The standard practice for cell-based, high content assays has been to assume a normal distribution and to report a well-to-well average value with a standard deviation. To address this important issue we sought to define a method that could be readily implemented to identify, quantify and characterize heterogeneity in cellular and small organism assays to guide decisions during drug discovery and experimental cell/tissue profiling. Our study revealed that heterogeneity can be effectively identified and quantified with three indices that indicate diversity, non-normality and percent outliers. The indices were evaluated using the induction and inhibition of STAT3 activation in five cell lines where the systems response including sample preparation and instrument performance were well characterized and controlled. These heterogeneity indices provide a standardized method that can easily be integrated into small and large scale screening or profiling projects to guide interpretation of the biology, as well as the development of therapeutics and diagnostics. Understanding the heterogeneity in the response to perturbagens will become a critical factor in designing strategies for the development of therapeutics including targeted polypharmacology.

Test-treatment RCTs are susceptible to bias: a review of the methodological quality of randomized trials that evaluate diagnostic tests.

PubMed

Ferrante di Ruffano, Lavinia; Dinnes, Jacqueline; Sitch, Alice J; Hyde, Chris; Deeks, Jonathan J

2017-02-24

There is a growing recognition for the need to expand our evidence base for the clinical effectiveness of diagnostic tests. Many international bodies are calling for diagnostic randomized controlled trials to provide the most rigorous evidence of impact to patient health. Although these so-called test-treatment RCTs are very challenging to undertake due to their methodological complexity, they have not been subjected to a systematic appraisal of their methodological quality. The extent to which these trials may be producing biased results therefore remains unknown. We set out to address this issue by conducting a methodological review of published test-treatment trials to determine how often they implement adequate methods to limit bias and safeguard the validity of results. We ascertained all test-treatment RCTs published 2004-2007, indexed in CENTRAL, including RCTs which randomized patients to diagnostic tests and measured patient outcomes after treatment. Tests used for screening, monitoring or prognosis were excluded. We assessed adequacy of sequence generation, allocation concealment and intention-to-treat, appropriateness of primary analyses, blinding and reporting of power calculations, and extracted study characteristics including the primary outcome. One hundred three trials compared 105 control with 119 experimental interventions, and reported 150 primary outcomes. Randomization and allocation concealment were adequate in 57 and 37% of trials. Blinding was uncommon (patients 5%, clinicians 4%, outcome assessors 21%), as was an adequate intention-to-treat analysis (29%). Overall 101 of 103 trials (98%) were at risk of bias, as judged using standard Cochrane criteria. Test-treatment trials are particularly susceptible to attrition and inadequate primary analyses, lack of blinding and under-powering. These weaknesses pose much greater methodological and practical challenges to conducting reliable RCT evaluations of test-treatment strategies than standard treatment interventions. We suggest a cautious approach that first examines whether a test-treatment intervention can accommodate the methodological safeguards necessary to minimize bias, and highlight that test-treatment RCTs require different methods to ensure reliability than standard treatment trials. Please see the companion paper to this article: http://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-016-0286-0 .

Contribution of diffusion weighted MRI to diagnosis and staging in gastric tumors and comparison with multi-detector computed tomography.

PubMed

Arslan, Harun; Fatih Özbay, Mehmet; Çallı, İskan; Doğan, Erkan; Çelik, Sebahattin; Batur, Abdussamet; Bora, Aydın; Yavuz, Alpaslan; Bulut, Mehmet Deniz; Özgökçe, Mesut; Çetin Kotan, Mehmet

2017-03-01

Diagnostic performance of Diffusion-Weighted magnetic resonance Imaging (DWI) and Multi-Detector Computed Tomography (MDCT) for TNM (Tumor, Lymph node, Metastasis) staging of gastric cancer was compared. We used axial T2-weighted images and DWI (b-0,400 and b-800 s/mm2) protocol on 51 pre-operative patients who had been diagnosed with gastric cancer. We also conducted MDCT examinations on them. We looked for a signal increase in the series of DWI images. The depth of tumor invasion in the stomach wall (tumor (T) staging), the involvement of lymph nodes (nodal (N) staging), and the presence or absence of metastases (metastatic staging) in DWI and CT images according to the TNM staging system were evaluated. In each diagnosis of the tumors, sensitivity, specificity, positive and negative accuracy rates of DWI and MDCT examinations were found through a comparison with the results of the surgical pathology, which is the gold standard method. In addition to the compatibilities of each examination with surgical pathology, kappa statistics were used. Sensitivity and specificity of DWI and MDCT in lymph node staging were as follows: N1: DWI: 75.0%, 84.6%; MDCT: 66.7%, 82%;N2: DWI: 79.3%, 77.3%; MDCT: 69.0%, 68.2%; N3: DWI: 60.0%, 97.6%; MDCT: 50.0%, 90.2%. The diagnostic tool DWI seemed more compatible with the gold standard method (surgical pathology), especially in the staging of lymph node, when compared to MDCT. On the other hand, in T staging, the results of DWI and MDCT were better than the gold standard when the T stage increased. However, DWI did not demonstrate superiority to MDCT. The sensitivity and specificity of both imaging techniques for detecting distant metastasis were 100%. The diagnostic accuracy of DWI for TNM staging in gastric cancer before surgery is at a comparable level with MDCT and adding DWI to routine protocol of evaluating lymph nodes metastasis might increase diagnostic accuracy.

A novel quantitative reverse-transcription PCR (qRT-PCR) for the enumeration of total bacteria, using meat micro-flora as a model.

PubMed

Dolan, Anthony; Burgess, Catherine M; Barry, Thomas B; Fanning, Seamus; Duffy, Geraldine

2009-04-01

A sensitive quantitative reverse-transcription PCR (qRT-PCR) method was developed for enumeration of total bacteria. Using two sets of primers separately to target the ribonuclease-P (RNase P) RNA transcripts of gram positive and gram negative bacteria. Standard curves were generated using SYBR Green I kits for the LightCycler 2.0 instrument (Roche Diagnostics) to allow quantification of mixed microflora in liquid media. RNA standards were used and extracted from known cell equivalents and subsequently converted to cDNA for the construction of standard curves. The number of mixed bacteria in culture was determined by qRT-PCR, and the results correlated (r(2)=0.88, rsd=0.466) with the total viable count over the range from approx. Log(10) 3 to approx. Log(10) 7 CFU ml(-1). The rapid nature of this assay (8 h) and its potential as an alternative method to the standard plate count method to predict total viable counts and shelf life are discussed.

Endobronchial Ultrasound-guided Transbronchial Needle Aspiration versus Standard Bronchoscopic Modalities for Diagnosis of Sarcoidosis: A Meta-analysis

PubMed Central

Hu, Li-Xing; Chen, Ru-Xuan; Huang, Hui; Shao, Chi; Wang, Ping; Liu, Yong-Zhe; Xu, Zuo-Jun

2016-01-01

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an effective technique used to precisely detect enlarged mediastinal lymph nodes. The efficacy of EBUS-TBNA versus standard modalities for the diagnosis of sarcoidosis remains to be elucidated. In this meta-analysis, we compared the efficacies of these methods. Methods: We searched PubMed, Embase, The Cochrane Library, Wanfang, Cpvip, CNKI, and the bibliographies of the relevant references. We analyzed the data obtained with Revman 5.2 (Nordic Cochrane Center, Copenhagen, Denmark) and Stata 12.0 software (Stata Corporation, College Station, TX, USA). The Mantel-Haenszel method was used to calculate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Results: Sixteen studies with a total of 1823 participants met the inclusion criteria, and data were extracted regarding the diagnostic yield of each approach. The ORs for EBUS-TBNA versus transbronchial lung biopsy (TBLB) for the diagnosis of sarcoidosis ranged from 0.26 to 126.58, and the pooled OR was 5.89 (95% CI, 2.20–15.79, P = 0.0004). These findings indicated that EBUS-TBNA provided a much higher diagnostic yield than TBLB. The pooled OR for EBUS-TBNA + TBLB + endobronchial biopsy (EBB) versus TBNA + TBLB + EBB was 1.54 (95% CI, 0.61–3.93, P = 0.36), implying that there was no significant difference between their diagnostic yields. However, clinical heterogeneity was reflected in the nature of the studies and in the operative variables. Conclusions: The results of this meta-analysis suggest that EBUS-TBNA + TBLB + EBB could be used for the diagnosis of sarcoidosis, if available. At medical centers without EBUS-TBNA, TBNA + TBLB + EBB could be used instead. PMID:27364799

Performance of seven serological assays for diagnosing tularemia

PubMed Central

2014-01-01

Background Tularemia is a rare zoonotic disease caused by the Gram-negative bacterium Francisella tularensis. Serology is frequently the preferred diagnostic approach, because the pathogen is highly infectious and difficult to cultivate. The aim of this retrospective study was to determine the diagnostic accuracy of tularemia specific tests. Methods The Serazym®Anti-Francisella tularensis ELISA, Serion ELISA classic Francisella tularensis IgG/IgM, an in-house ELISA, the VIRapid® Tularemia immunochromatographic test, an in-house antigen microarray, and a Western Blot (WB) assay were evaluated. The diagnosis tularemia was established using a standard micro-agglutination assay. In total, 135 sera from a series of 110 consecutive tularemia patients were tested. Results The diagnostic sensitivity and diagnostic specificity of the tests were VIRapid (97.0% and 84.0%), Serion IgG (96.3% and 96.8%), Serion IgM (94.8% and 96.8%), Serazym (97.0% and 91.5%), in-house ELISA (95.6% and 76.6%), WB (93.3% and 83.0%), microarray (91.1% and 97.9%). Conclusions The diagnostic value of the commercial assays was proven, because the diagnostic accuracy was >90%. The diagnostic sensitivity of the in-house ELISA and the WB were acceptable, but the diagnostic accuracy was <90%. Interestingly, the antigen microarray test was very specific and had a very good positive predictive value. PMID:24885274

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, Yousef W., E-mail: yujwni01@heh.regionh.d; Eiberg, Jonas P., E-mail: Eiberg@dadlnet.d; Logager, Vibeke B., E-mail: viloe@heh.regionh.d

The purpose of this study was to determine the diagnostic performance of 3T whole-body magnetic resonance angiography (WB-MRA) using a hybrid protocol in comparison with a standard protocol in patients with peripheral arterial disease (PAD). In 26 consecutive patients with PAD two different protocols were used for WB-MRA: a standard sequential protocol (n = 13) and a hybrid protocol (n = 13). WB-MRA was performed using a gradient echo sequence, body coil for signal reception, and gadoterate meglumine as contrast agent (0.3 mmol/kg body weight). Two blinded observers evaluated all WB-MRA examinations with regard to presence of stenoses, as wellmore » as diagnostic quality and degree of venous contamination in each of the four stations used in WB-MRA. Digital subtraction angiography served as the method of reference. Sensitivity for detecting significant arterial disease (luminal narrowing {>=} 50%) using standard-protocol WB-MRA for the two observers was 0.63 (95%CI: 0.51-0.73) and 0.66 (0.58-0.78). Specificities were 0.94 (0.91-0.97) and 0.96 (0.92-0.98), respectively. In the hybrid protocol WB-MRA sensitivities were 0.75 (0.64-0.84) and 0.70 (0.58-0.8), respectively. Specificities were 0.93 (0.88-0.96) and 0.95 (0.91-0.97). Interobserver agreement was good using both the standard and the hybrid protocol, with {kappa} = 0.62 (0.44-0.67) and {kappa} = 0.70 (0.59-0.79), respectively. WB-MRA quality scores were significantly higher in the lower leg using the hybrid protocol compared to standard protocol (p = 0.003 and p = 0.03, observers 1 and 2). Distal venous contamination scores were significantly lower with the hybrid protocol (p = 0.02 and p = 0.01, observers 1 and 2). In conclusion, hybrid-protocol WB-MRA shows a better diagnostic performance than standard protocol WB-MRA at 3 T in patients with PAD.« less

Validation of diabetes mellitus and hypertension diagnosis in computerized medical records in primary health care

PubMed Central

2011-01-01

Background Computerized Clinical Records, which are incorporated in primary health care practice, have great potential for research. In order to use this information, data quality and reliability must be assessed to prevent compromising the validity of the results. The aim of this study is to validate the diagnosis of hypertension and diabetes mellitus in the computerized clinical records of primary health care, taking the diagnosis criteria established in the most prominently used clinical guidelines as the gold standard against which what measure the sensitivity, specificity, and determine the predictive values. The gold standard for diabetes mellitus was the diagnostic criteria established in 2003 American Diabetes Association Consensus Statement for diabetic subjects. The gold standard for hypertension was the diagnostic criteria established in the Joint National Committee published in 2003. Methods A cross-sectional multicentre validation study of diabetes mellitus and hypertension diagnoses in computerized clinical records of primary health care was carried out. Diagnostic criteria from the most prominently clinical practice guidelines were considered for standard reference. Sensitivity, specificity, positive and negative predictive values, and global agreement (with kappa index), were calculated. Results were shown overall and stratified by sex and age groups. Results The agreement for diabetes mellitus with the reference standard as determined by the guideline was almost perfect (κ = 0.990), with a sensitivity of 99.53%, a specificity of 99.49%, a positive predictive value of 91.23% and a negative predictive value of 99.98%. Hypertension diagnosis showed substantial agreement with the reference standard as determined by the guideline (κ = 0.778), the sensitivity was 85.22%, the specificity 96.95%, the positive predictive value 85.24%, and the negative predictive value was 96.95%. Sensitivity results were worse in patients who also had diabetes and in those aged 70 years or over. Conclusions Our results substantiate the validity of using diagnoses of diabetes and hypertension found within the computerized clinical records for epidemiologic studies. PMID:22035202

Diagnostic accuracy of 22/25-gauge core needle in endoscopic ultrasound-guided sampling: systematic review and meta-analysis.

PubMed

Oh, Hyoung-Chul; Kang, Hyun; Lee, Jae Young; Choi, Geun Joo; Choi, Jung Sik

2016-11-01

To compare the diagnostic accuracy of endoscopic ultrasound-guided core needle aspiration with that of standard fine-needle aspiration by systematic review and meta-analysis. Studies using 22/25-gauge core needles, irrespective of comparison with standard fine needles, were comprehensively reviewed. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curves for the diagnosis of malignancy were used to estimate the overall diagnostic efficiency. The pooled sensitivity, specificity, and DOR of the core needle for the diagnosis of malignancy were 0.88 (95% confidence interval [CI], 0.84 to 0.90), 0.99 (95% CI, 0.96 to 1), and 167.37 (95% CI, 65.77 to 425.91), respectively. The pooled sensitivity, specificity, and DOR of the standard needle were 0.84 (95% CI, 0.79 to 0.88), 1 (95% CI, 0.97 to 1), and 130.14 (95% CI, 34.00 to 495.35), respectively. The area under the curve of core and standard needle in the diagnosis of malignancy was 0.974 and 0.955, respectively. The core and standard needle were comparable in terms of pancreatic malignancy diagnosis. There was no significant difference in procurement of optimal histologic cores between core and standard needles (risk ratio [RR], 0.545; 95% CI, 0.187 to 1.589). The number of needle passes for diagnosis was significantly lower with the core needle (standardized mean difference, -0.72; 95% CI, -1.02 to -0.41). There were no significant differences in overall complications (RR, 1.26; 95% CI, 0.34 to 4.62) and technical failure (RR, 5.07; 95% CI, 0.68 to 37.64). Core and standard needles were comparable in terms of diagnostic accuracy, technical performance, and safety profile.

Optimal Combination of Non-Invasive Tools for the Early Detection of Potentially Life-Threatening Emergencies in Gynecology

PubMed Central

Varas, Catalina; Ravit, Marion; Mimoun, Camille; Panel, Pierre; Huchon, Cyrille; Fauconnier, Arnaud

2016-01-01

Objectives Potentially life-threatening gynecological emergencies (G-PLEs) are acute pelvic conditions that may spontaneously evolve into a life-threatening situation, or those for which there is a risk of sequelae or death in the absence of prompt diagnosis and treatment. The objective of this study was to identify the best combination of non-invasive diagnostic tools to ensure an accurate diagnosis and timely response when faced with G-PLEs for patients arriving with acute pelvic pain at the Gynecological Emergency Department (ED). Methods The data on non-invasive diagnostic tools were sourced from the records of patients presenting at the ED of two hospitals in the Parisian suburbs (France) with acute pelvic pain between September 2006 and April 2008. The medical history of the patients was obtained through a standardized questionnaire completed for a prospective observational study, and missing information was completed with data sourced from the medical forms. Diagnostic tool categories were predefined as a collection of signs or symptoms. We analyzed the association of each sign/symptom with G-PLEs using Pearson’s Chi-Square or Fischer’s exact tests. Symptoms and signs associated with G-PLEs (p-value < 0.20) were subjected to logistic regression to evaluate the diagnostic value of each of the predefined diagnostic tools and in various combinations. Results The data of 365 patients with acute pelvic pain were analyzed, of whom 103 were confirmed to have a PLE. We analyzed five diagnostic tools by logistic regression: Triage Process, History-Taking, Physical Examination, Ultrasonography, and Biological Exams. The combination of History-Taking and Ultrasonography had a C-index of 0.83, the highest for a model combining two tools. Conclusions The use of a standardized self-assessment questionnaire for history-taking and focal ultrasound examination were found to be the most successful tool combination for the diagnosis of gynecological emergencies in a Gynecological ED. Additional tools, such as physical examination, do not add substantial diagnostic value. PMID:27583697

The Quantitative Science of Evaluating Imaging Evidence.

PubMed

Genders, Tessa S S; Ferket, Bart S; Hunink, M G Myriam

2017-03-01

Cardiovascular diagnostic imaging tests are increasingly used in everyday clinical practice, but are often imperfect, just like any other diagnostic test. The performance of a cardiovascular diagnostic imaging test is usually expressed in terms of sensitivity and specificity compared with the reference standard (gold standard) for diagnosing the disease. However, evidence-based application of a diagnostic test also requires knowledge about the pre-test probability of disease, the benefit of making a correct diagnosis, the harm caused by false-positive imaging test results, and potential adverse effects of performing the test itself. To assist in clinical decision making regarding appropriate use of cardiovascular diagnostic imaging tests, we reviewed quantitative concepts related to diagnostic performance (e.g., sensitivity, specificity, predictive values, likelihood ratios), as well as possible biases and solutions in diagnostic performance studies, Bayesian principles, and the threshold approach to decision making. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Quantifying serum antibody in bird fanciers' hypersensitivity pneumonitis.

PubMed

McSharry, Charles; Dye, George M; Ismail, Tengku; Anderson, Kenneth; Spiers, Elizabeth M; Boyd, Gavin

2006-06-26

Detecting serum antibody against inhaled antigens is an important diagnostic adjunct for hypersensitivity pneumonitis (HP). We sought to validate a quantitative fluorimetric assay testing serum from bird fanciers. Antibody activity was assessed in bird fanciers and control subjects using various avian antigens and serological methods, and the titer was compared with symptoms of HP. IgG antibody against pigeon serum antigens, quantified by fluorimetry, provided a good discriminator of disease. Levels below 10 mg/L were insignificant, and increasing titers were associated with disease. The assay was unaffected by total IgG, autoantibodies and antibody to dietary hen's egg antigens. Antigens from pigeon serum seem sufficient to recognize immune sensitivity to most common pet avian species. Decreasing antibody titers confirmed antigen avoidance. Increasing antibody titer reflected the likelihood of HP, and decreasing titers confirmed antigen avoidance. Quantifying antibody was rapid and the increased sensitivity will improve the rate of false-negative reporting and obviate the need for invasive diagnostic procedures. Automated fluorimetry provides a method for the international standardization of HP serology thereby improving quality control and improving its suitability as a diagnostic adjunct.

Malaria Diagnosis across the International Centers of Excellence for Malaria Research: Platforms, Performance, and Standardization

PubMed Central

Kobayashi, Tamaki; Gamboa, Dionicia; Ndiaye, Daouda; Cui, Liwang; Sutton, Patrick L.; Vinetz, Joseph M.

2015-01-01

Diagnosis is “the act of identifying a disease, illness, or problem by examining someone or something.” When an individual with acute fever presents for clinical attention, accurate diagnosis leading to specific, prompt treatment often saves lives. As applied to malaria, not only individual patient diagnosis is important but also assessing population-level malaria prevalence using appropriate diagnostic methods is essential for public health purposes. Similarly, identifying (diagnosing) fake antimalarial medications prevents the use of counterfeit drugs that can have disastrous effects. Therefore, accurate diagnosis in broad areas related to malaria is fundamental to improving health-care delivery, informing funding agencies of current malaria situations, and aiding in the prioritization of regional and national control efforts. The International Centers of Excellence for Malaria Research (ICEMR), supported by the U.S. National Institute of Allergy and Infectious Diseases, has collaborated on global efforts to improve malaria diagnostics by working to harmonize and systematize procedures across different regions where endemicity and financial resources vary. In this article, the different diagnostic methods used across each ICEMR are reviewed and challenges are discussed. PMID:26259937

Design issues in a randomized controlled trial of a pre-emptive versus empiric antifungal strategy for invasive aspergillosis in patients with high-risk hematologic malignancies.

PubMed

Morrissey, C Orla; Chen, Sharon C-A; Sorrell, Tania C; Bradstock, Kenneth F; Szer, Jeffrey; Halliday, Catriona L; Gilroy, Nicole M; Schwarer, Anthony P; Slavin, Monica A

2011-02-01

Invasive aspergillosis (IA) is a major cause of mortality in patients with hematological malignancies, due largely to the inability of traditional culture and biopsy methods to make an early or accurate diagnosis. Diagnostic accuracy studies suggest that Aspergillus galactomannan (GM) enzyme immunoassay (ELISA) and Aspergillus PCR-based methods may overcome these limitations, but their impact on patient outcomes should be evaluated in a diagnostic randomized controlled trial (D-RCT). This article describes the methodology of a D-RCT which compares a new pre-emptive strategy (GM-ELISA- and Aspergillus PCR-driven antifungal therapy) with the standard fever-driven empiric antifungal treatment strategy. Issues including primary end-point and patient selection, duration of screening, choice of tests for the pre-emptive strategy, antifungal prophylaxis and bias control, which were considered in the design of the trial, are discussed. We suggest that the template presented herein is considered by researchers when evaluating the utility of new diagnostic tests (ClinicalTrials.gov number, NCT00163722).

Developing standards for malaria microscopy: external competency assessment for malaria microscopists in the Asia-Pacific.

PubMed

Ashraf, Sania; Kao, Angie; Hugo, Cecilia; Christophel, Eva M; Fatunmbi, Bayo; Luchavez, Jennifer; Lilley, Ken; Bell, David

2012-10-24

Malaria diagnosis has received renewed interest in recent years, associated with the increasing accessibility of accurate diagnosis through the introduction of rapid diagnostic tests and new World Health Organization guidelines recommending parasite-based diagnosis prior to anti-malarial therapy. However, light microscopy, established over 100 years ago and frequently considered the reference standard for clinical diagnosis, has been neglected in control programmes and in the malaria literature and evidence suggests field standards are commonly poor. Microscopy remains the most accessible method for parasite quantitation, for drug efficacy monitoring, and as a reference of assessing other diagnostic tools. This mismatch between quality and need highlights the importance of the establishment of reliable standards and procedures for assessing and assuring quality. This paper describes the development, function and impact of a multi-country microscopy external quality assurance network set up for this purpose in Asia. Surveys were used for key informants and past participants for feedback on the quality assurance programme. Competency scores for each country from 14 participating countries were compiled for analyses using paired sample t-tests. In-depth interviews were conducted with key informants including the programme facilitators and national level microscopists. External assessments and limited retraining through a formalized programme based on a reference slide bank has demonstrated an increase in standards of competence of senior microscopists over a relatively short period of time, at a potentially sustainable cost. The network involved in the programme now exceeds 14 countries in the Asia-Pacific, and the methods are extended to other regions. While the impact on national programmes varies, it has translated in some instances into a strengthening of national microscopy standards and offers a possibility both for supporting revival of national microcopy programmes, and for the development of globally recognized standards of competency needed both for patient management and field research.

Diagnostic Capability of Biological Markers in Assessment of Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

PubMed Central

De Luca Canto, Graziela; Pachêco-Pereira, Camila; Aydinoz, Secil; Major, Paul W.; Flores-Mir, Carlos; Gozal, David

2015-01-01

Objective: The purpose of this systematic review is to evaluate the diagnostic value of biological markers (exhaled breath condensate, blood, salivary and urinary) in the diagnosis of OSA in comparison to the gold standard of nocturnal PSG. Methods: Studies that differentiated OSA from controls based on PSG results, without age restriction, were eligible for inclusion. The sample of selected studies could include studies in obese patients and with known cardiac disease. A detailed individual search strategy for each of the following bibliographic databases was developed: Cochrane, EMBASE, MEDLINE, PubMed, and LILACS. The references cited in these articles were also crosschecked and a partial grey literature search was undertaken using Google Scholar. The methodology of selected studies was evaluated using the 14-item Quality Assessment Tool for Diagnostic Accuracy Studies. Results: After a two-step selection process, nine articles were identified and subjected to qualitative and quantitative analyses. Among them, only one study conducted in children and one in adults found biomarkers that exhibit sufficiently satisfactory diagnostic accuracy that enables application as a diagnostic method for OSA. Conclusion: Kallikrein-1, uromodulin, urocotin-3, and orosomucoid-1 when combined have enough accuracy to be an OSA diagnostic test in children. IL-6 and IL-10 plasma levels have potential to be good biomarkers in identifying or excluding the presence of OSA in adults. Citation: De Luca Canto G, Pachêco-Pereira C, Aydinoz S, Major PW, Flores-Mir C, Gozal D. Diagnostic capability of biological markers in assessment of obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med 2015;11(1):27–36. PMID:25325575

Long-Term Effects of Environment on Health and Performance of Antarctic Winter-Over Personnel.

DTIC Science & Technology

1985-12-01

and increased psychological disturbances (Gunderson, 1963; Gunderson, 1968; Mullin, 1960; Palmai, 1963). The environments of Antarctic research...diagnostic categories of first hospitalizations were calculated using the direct method of adjustment ( Lilienfeld and Lilienfeld , 1980). The standard...analysis of variance and chi-square tests were employed to S".... ..... ...................-... ... "’:" determine levels of significance for observed

Assessing the effectiveness of problem-based learning in physical diagnostics education in China: a meta-analysis

PubMed Central

Wang, Jianmiao; Xu, Yongjian; Liu, Xiansheng; Xiong, Weining; Xie, Jungang; Zhao, Jianping

2016-01-01

Problem-based learning (PBL) has been extensively applied as an experimental educational method in Chinese medical schools over the past decade. A meta-analysis was performed to assess the effectiveness of PBL on students’ learning outcomes in physical diagnostics education. Related databases were searched for eligible studies evaluating the effects of PBL compared to traditional teaching on students’ knowledge and/or skill scores of physical diagnostics. Standardized mean difference (SMD) with 95% confidence interval (CI) was estimated. Thirteen studies with a total of 2086 medical students were included in this meta-analysis. All of these studies provided usable data on knowledge scores, and the pooled analysis showed a significant difference in favor of PBL compared to the traditional teaching (SMD = 0.76, 95%CI = 0.33–1.19). Ten studies provided usable data on skill scores, and a significant difference in favor of PBL was also observed (SMD = 1.46, 95%CI = 0.89–2.02). Statistically similar results were obtained in the sensitivity analysis, and there was no significant evidence of publication bias. These results suggested that PBL in physical diagnostics education in China appeared to be more effective than traditional teaching method in improving knowledge and skills. PMID:27808158

Assessing the effectiveness of problem-based learning in physical diagnostics education in China: a meta-analysis.

PubMed

Wang, Jianmiao; Xu, Yongjian; Liu, Xiansheng; Xiong, Weining; Xie, Jungang; Zhao, Jianping

2016-11-03

Problem-based learning (PBL) has been extensively applied as an experimental educational method in Chinese medical schools over the past decade. A meta-analysis was performed to assess the effectiveness of PBL on students' learning outcomes in physical diagnostics education. Related databases were searched for eligible studies evaluating the effects of PBL compared to traditional teaching on students' knowledge and/or skill scores of physical diagnostics. Standardized mean difference (SMD) with 95% confidence interval (CI) was estimated. Thirteen studies with a total of 2086 medical students were included in this meta-analysis. All of these studies provided usable data on knowledge scores, and the pooled analysis showed a significant difference in favor of PBL compared to the traditional teaching (SMD = 0.76, 95%CI = 0.33-1.19). Ten studies provided usable data on skill scores, and a significant difference in favor of PBL was also observed (SMD = 1.46, 95%CI = 0.89-2.02). Statistically similar results were obtained in the sensitivity analysis, and there was no significant evidence of publication bias. These results suggested that PBL in physical diagnostics education in China appeared to be more effective than traditional teaching method in improving knowledge and skills.

Diagnostic accuracy research in glaucoma is still incompletely reported: An application of Standards for Reporting of Diagnostic Accuracy Studies (STARD) 2015.

PubMed

Michelessi, Manuele; Lucenteforte, Ersilia; Miele, Alba; Oddone, Francesco; Crescioli, Giada; Fameli, Valeria; Korevaar, Daniël A; Virgili, Gianni

2017-01-01

Research has shown a modest adherence of diagnostic test accuracy (DTA) studies in glaucoma to the Standards for Reporting of Diagnostic Accuracy Studies (STARD). We have applied the updated 30-item STARD 2015 checklist to a set of studies included in a Cochrane DTA systematic review of imaging tools for diagnosing manifest glaucoma. Three pairs of reviewers, including one senior reviewer who assessed all studies, independently checked the adherence of each study to STARD 2015. Adherence was analyzed on an individual-item basis. Logistic regression was used to evaluate the effect of publication year and impact factor on adherence. We included 106 DTA studies, published between 2003-2014 in journals with a median impact factor of 2.6. Overall adherence was 54.1% for 3,286 individual rating across 31 items, with a mean of 16.8 (SD: 3.1; range 8-23) items per study. Large variability in adherence to reporting standards was detected across individual STARD 2015 items, ranging from 0 to 100%. Nine items (1: identification as diagnostic accuracy study in title/abstract; 6: eligibility criteria; 10: index test (a) and reference standard (b) definition; 12: cut-off definitions for index test (a) and reference standard (b); 14: estimation of diagnostic accuracy measures; 21a: severity spectrum of diseased; 23: cross-tabulation of the index and reference standard results) were adequately reported in more than 90% of the studies. Conversely, 10 items (3: scientific and clinical background of the index test; 11: rationale for the reference standard; 13b: blinding of index test results; 17: analyses of variability; 18; sample size calculation; 19: study flow diagram; 20: baseline characteristics of participants; 28: registration number and registry; 29: availability of study protocol; 30: sources of funding) were adequately reported in less than 30% of the studies. Only four items showed a statistically significant improvement over time: missing data (16), baseline characteristics of participants (20), estimates of diagnostic accuracy (24) and sources of funding (30). Adherence to STARD 2015 among DTA studies in glaucoma research is incomplete, and only modestly increasing over time.

Textual standardization and the DSM-5 "common language".

PubMed

Kelly, Patty A

2014-06-01

In February 2010, the American Psychiatric Association (APA) launched their DSM-5 website with details about the development of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The APA invited "the general public" to review the draft diagnostic criteria and provide written comments and suggestions. This revision marks the first time the APA has solicited public review of their diagnostic manual. This article analyzes reported speech on the DSM-5 draft diagnostic criteria for the classification Posttraumatic Stress Disorder. It demonstrates how textual standardization facilitates the cultural portability of the DSM-5 diagnostic criteria such that a community of speakers beyond the borders of the APA come to be seen as exemplary speakers, writers, and revisers of the professional style. Furthermore, analysis shows how co-authoring practices recontextualize the "voice" and persona of putative patient reported speech on Criterion D2. As a consequence of textual standardization, spoken discourse becomes recontextualized as the product of scientific inquiry and the organization of psychiatric knowledge.

Does Quantitative Tibial Ultrasound Predict Low Bone Mineral Density Defined by Dual Energy X-Ray Absorptiometry?

PubMed Central

Birtane, Murat; Ekuklu, Galip; Cermik, Fikret; Tuna, Filiz; Kokino, Siranus

2008-01-01

Purpose Efforts for the early detection of bone loss and subsequent fracture risk by quantitative ultrasound (QUS), which is a non-invasive, radiation free, and cheaper method, seem rational to reduce the management costs. We aimed in this study to assess the probable correlation of speed of sound (SOS) values obtained by QUS with bone mineral density (BMD) as measured by the gold standard method, dual energy X-ray absorptiometry (DEXA), and to investigate the diagnostic value of QUS to define low BMD. Materials and Methods One hundred twenty-two postmenopausal women having prior standard DEXA measurements were included in the study. Spine and proximal femur (neck, trochanter and Ward's triangle) BMD were assessed in a standard protocol by DEXA. The middle point of the right tibia was chosen for SOS measurement by tibial QUS. Results The SOS values were observed to be significantly higher in the normal BMD (t score > - 1) group at all measurement sites except for the lumbar region, when compared with the low BMD group (t score < - 1). SOS was negatively correlated with age (r = - 0.66) and month since menopause (r = - 0.57). The sensitivity, specificity, and positive and negative predictive values for QUS t score to diagnose low BMD did not seem to be satisfactory at either of the measurement sites. Conclusion Tibial SOS was correlated weakly with BMD values of femur and lumbar spine as measured by DEXA and its diagnostic value did not seem to be high for discriminating between normal and low BMD, at these sites. PMID:18581594

Added value of cost-utility analysis in simple diagnostic studies of accuracy: (18)F-fluoromethylcholine PET/CT in prostate cancer staging.

PubMed

Gerke, Oke; Poulsen, Mads H; Høilund-Carlsen, Poul Flemming

2015-01-01

Diagnostic studies of accuracy targeting sensitivity and specificity are commonly done in a paired design in which all modalities are applied in each patient, whereas cost-effectiveness and cost-utility analyses are usually assessed either directly alongside to or indirectly by means of stochastic modeling based on larger randomized controlled trials (RCTs). However the conduct of RCTs is hampered in an environment such as ours, in which technology is rapidly evolving. As such, there is a relatively limited number of RCTs. Therefore, we investigated as to which extent paired diagnostic studies of accuracy can be also used to shed light on economic implications when considering a new diagnostic test. We propose a simple decision tree model-based cost-utility analysis of a diagnostic test when compared to the current standard procedure and exemplify this approach with published data from lymph node staging of prostate cancer. Average procedure costs were taken from the Danish Diagnosis Related Groups Tariff in 2013 and life expectancy was estimated for an ideal 60 year old patient based on prostate cancer stage and prostatectomy or radiation and chemotherapy. Quality-adjusted life-years (QALYs) were deduced from the literature, and an incremental cost-effectiveness ratio (ICER) was used to compare lymph node dissection with respective histopathological examination (reference standard) and (18)F-fluoromethylcholine positron emission tomography/computed tomography (FCH-PET/CT). Lower bounds of sensitivity and specificity of FCH-PET/CT were established at which the replacement of the reference standard by FCH-PET/CT comes with a trade-off between worse effectiveness and lower costs. Compared to the reference standard in a diagnostic accuracy study, any imperfections in accuracy of a diagnostic test imply that replacing the reference standard generates a loss in effectiveness and utility. We conclude that diagnostic studies of accuracy can be put to a more extensive use, over and above a mere indication of sensitivity and specificity of an imaging test, and that health economic considerations should be undertaken when planning a prospective diagnostic accuracy study. These endeavors will prove especially fruitful when comparing several imaging techniques with one another, or the same imaging technique using different tracers, with an independent reference standard for the evaluation of results.

Diagnostic accuracy of optical coherence tomography in actinic keratosis and basal cell carcinoma.

PubMed

Olsen, J; Themstrup, L; De Carvalho, N; Mogensen, M; Pellacani, G; Jemec, G B E

2016-12-01

Early diagnosis of non-melanoma skin cancer (NMSC) is potentially possible using optical coherence tomography (OCT) which provides non-invasive, real-time images of skin with micrometre resolution and an imaging depth of up to 2mm. OCT technology for skin imaging has undergone significant developments, improving image quality substantially. The diagnostic accuracy of any method is influenced by continuous technological development making it necessary to regularly re-evaluate methods. The objective of this study is to estimate the diagnostic accuracy of OCT in basal cell carcinomas (BCC) and actinic keratosis (AK) as well as differentiating these lesions from normal skin. A study set consisting of 142 OCT images meeting selection criterea for image quality and diagnosis of AK, BCC and normal skin was presented uniformly to two groups of blinded observers: 5 dermatologists experienced in OCT-image interpretation and 5 dermatologists with no experience in OCT. During the presentation of the study set the observers filled out a standardized questionnaire regarding the OCT diagnosis. Images were captured using a commercially available OCT machine (Vivosight ® , Michelson Diagnostics, UK). Skilled OCT observers were able to diagnose BCC lesions with a sensitivity of 86% to 95% and a specificity of 81% to 98%. Skilled observers with at least one year of OCT-experience showed an overall higher diagnostic accuracy compared to inexperienced observers. The study shows an improved diagnostic accuracy of OCT in differentiating AK and BCC from healthy skin using state-of-the-art technology compared to earlier OCT technology, especially concerning BCC diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Advancing Diagnostics to Address Antibacterial Resistance: The Diagnostics and Devices Committee of the Antibacterial Resistance Leadership Group.

PubMed

Tsalik, Ephraim L; Petzold, Elizabeth; Kreiswirth, Barry N; Bonomo, Robert A; Banerjee, Ritu; Lautenbach, Ebbing; Evans, Scott R; Hanson, Kimberly E; Klausner, Jeffrey D; Patel, Robin

2017-03-15

Diagnostics are a cornerstone of the practice of infectious diseases. However, various limitations frequently lead to unmet clinical needs. In most other domains, diagnostics focus on narrowly defined questions, provide readily interpretable answers, and use true gold standards for development. In contrast, infectious diseases diagnostics must contend with scores of potential pathogens, dozens of clinical syndromes, emerging pathogens, rapid evolution of existing pathogens and their associated resistance mechanisms, and the absence of gold standards in many situations. In spite of these challenges, the importance and value of diagnostics cannot be underestimated. Therefore, the Antibacterial Resistance Leadership Group has identified diagnostics as 1 of 4 major areas of emphasis. Herein, we provide an overview of that development, highlighting several examples where innovation in study design, content, and execution is advancing the field of infectious diseases diagnostics. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Diagnostic Performance of Artificial Neural Network for Detecting Ischemia in Myocardial Perfusion Imaging.

PubMed

Nakajima, Kenichi; Matsuo, Shinro; Wakabayashi, Hiroshi; Yokoyama, Kunihiko; Bunko, Hisashi; Okuda, Koichi; Kinuya, Seigo; Nyström, Karin; Edenbrandt, Lars

2015-01-01

The purpose of this study was to apply an artificial neural network (ANN) in patients with coronary artery disease (CAD) and to characterize its diagnostic ability compared with conventional visual and quantitative methods in myocardial perfusion imaging (MPI). A total of 106 patients with CAD were studied with MPI, including multiple vessel disease (49%), history of myocardial infarction (27%) and coronary intervention (30%). The ANN detected abnormal areas with a probability of stress defect and ischemia. The consensus diagnosis based on expert interpretation and coronary stenosis was used as the gold standard. The left ventricular ANN value was higher in the stress-defect group than in the no-defect group (0.92±0.11 vs. 0.25±0.32, P<0.0001) and higher in the ischemia group than in the no-ischemia group (0.70±0.40 vs. 0.004±0.032, P<0.0001). Receiver-operating characteristics curve analysis showed comparable diagnostic accuracy between ANN and the scoring methods (0.971 vs. 0.980 for stress defect, and 0.882 vs. 0.937 for ischemia, both P=NS). The relationship between the ANN and defect scores was non-linear, with the ANN rapidly increased in ranges of summed stress score of 2-7 and summed defect score of 2-4. Although the diagnostic ability of ANN was similar to that of conventional scoring methods, the ANN could provide a different viewpoint for judging abnormality, and thus is a promising method for evaluating abnormality in MPI.

Assessment of biosafety precautions in Khartoum state diagnostic laboratories, Sudan

PubMed Central

Elduma, Adel Hussein

2012-01-01

Background This study was conducted to evaluate the biosafety precautions that applied by diagnostic laboratories in Khartoum state, 2009. Methods A total number of 190 laboratories were surveyed about their compliance with standard biosafety precautions. These laboratories included 51 (27%) laboratories from government, 75 (39%) from private sectors and 64 (34%) laboratories belong to organization providing health care services. Results The study found that 32 (16.8%) of laboratories appointed biosafety officers. Only, ten (5.2%) participated in training about response to fire emergency, and 28 (14.7%) reported the laboratory accident occurred during work. 45 (23.7%) laboratories had a written standard operation procedures (SOPs), and 35 (18.4%) had written procedures for the lean-up of spills. Moreover, biosafety cabinet was found in 11 (5.8%) laboratories, autoclave in 28 (14.7%) and incinerator in only two (1.1%) laboratories. Sharp disposable containers were found in 84 (44.2%). Fire alarm system was found in 2 (1.1%) laboratories, fire extinguisher in 39 (20.5%) laboratories, and fire emergency exit found in 14 (7.4%) laboratories. Furthermore, 19 (10%) laboratories had a hepatitis B virus vaccination programme, 5 (6.2%) applied BCG vaccine, and 2 (1.1%0) vaccinated the staff against influenza. Conclusion The study concluded that the standards biosafety precautions adopted by the diagnostic laboratories in Khartoum state was very low. Further, the laboratory personnel awareness towards biosafety principles implementation was very low too. PMID:22514753

The STARD statement for reporting diagnostic accuracy studies: application to the history and physical examination.

PubMed

Simel, David L; Rennie, Drummond; Bossuyt, Patrick M M

2008-06-01

The Standards for Reporting of Diagnostic Accuracy (STARD) statement provided guidelines for investigators conducting diagnostic accuracy studies. We reviewed each item in the statement for its applicability to clinical examination diagnostic accuracy research, viewing each discrete aspect of the history and physical examination as a diagnostic test. Nonsystematic review of the STARD statement. Two former STARD Group participants and 1 editor of a journal series on clinical examination research reviewed each STARD item. Suggested interpretations and comments were shared to develop consensus. The STARD Statement applies generally well to clinical examination diagnostic accuracy studies. Three items are the most important for clinical examination diagnostic accuracy studies, and investigators should pay particular attention to their requirements: describe carefully the patient recruitment process, describe participant sampling and address if patients were from a consecutive series, and describe whether the clinicians were masked to the reference standard tests and whether the interpretation of the reference standard test was masked to the clinical examination components or overall clinical impression. The consideration of these and the other STARD items in clinical examination diagnostic research studies would improve the quality of investigations and strengthen conclusions reached by practicing clinicians. The STARD statement provides a very useful framework for diagnostic accuracy studies. The group correctly anticipated that there would be nuances applicable to studies of the clinical examination. We offer guidance that should enhance their usefulness to investigators embarking on original studies of a patient's history and physical examination.

Correction of Near-infrared High-resolution Spectra for Telluric Absorption at 0.90–1.35 μm

NASA Astrophysics Data System (ADS)

Sameshima, Hiroaki; Matsunaga, Noriyuki; Kobayashi, Naoto; Kawakita, Hideyo; Hamano, Satoshi; Ikeda, Yuji; Kondo, Sohei; Fukue, Kei; Taniguchi, Daisuke; Mizumoto, Misaki; Arai, Akira; Otsubo, Shogo; Takenaka, Keiichi; Watase, Ayaka; Asano, Akira; Yasui, Chikako; Izumi, Natsuko; Yoshikawa, Tomohiro

2018-07-01

We report a method of correcting a near-infrared (0.90–1.35 μm) high-resolution (λ/Δλ ∼ 28,000) spectrum for telluric absorption using the corresponding spectrum of a telluric standard star. The proposed method uses an A0 V star or its analog as a standard star from which on the order of 100 intrinsic stellar lines are carefully removed with the help of a reference synthetic telluric spectrum. We find that this method can also be applied to feature-rich objects having spectra with heavily blended intrinsic stellar and telluric lines and present an application to a G-type giant using this approach. We also develop a new diagnostic method for evaluating the accuracy of telluric correction and use it to demonstrate that our method achieves an accuracy better than 2% for spectral parts for which the atmospheric transmittance is as low as ∼20% if telluric standard stars are observed under the following conditions: (1) the difference in airmass between the target and the standard is ≲ 0.05; and (2) that in time is less than 1 hr. In particular, the time variability of water vapor has a large impact on the accuracy of telluric correction and minimizing the difference in time from that of the telluric standard star is important especially in near-infrared high-resolution spectroscopic observation.

Development of an integrated Sasang constitution diagnosis method using face, body shape, voice, and questionnaire information

PubMed Central

2012-01-01

Background Sasang constitutional medicine (SCM) is a unique form of traditional Korean medicine that divides human beings into four constitutional types (Tae-Yang: TY, Tae-Eum: TE, So-Yang: SY, and So-Eum: SE), which differ in inherited characteristics, such as external appearance, personality traits, susceptibility to particular diseases, drug responses, and equilibrium among internal organ functions. According to SCM, herbs that belong to a certain constitution cannot be used in patients with other constitutions; otherwise, this practice may result in no effect or in an adverse effect. Thus, the diagnosis of SC type is the most crucial step in SCM practice. The diagnosis, however, tends to be subjective due to a lack of quantitative standards for SC diagnosis. Methods We have attempted to make the diagnosis method as objective as possible by basing it on an analysis of quantitative data from various Oriental medical clinics. Four individual diagnostic models were developed with multinomial logistic regression based on face, body shape, voice, and questionnaire responses. Inspired by SCM practitioners’ holistic diagnostic processes, an integrated diagnostic model was then proposed by combining the four individual models. Results The diagnostic accuracies in the test set, after the four individual models had been integrated into a single model, improved to 64.0% and 55.2% in the male and female patient groups, respectively. Using a cut-off value for the integrated SC score, such as 1.6, the accuracies increased by 14.7% in male patients and by 4.6% in female patients, which showed that a higher integrated SC score corresponded to a higher diagnostic accuracy. Conclusions This study represents the first trial of integrating the objectification of SC diagnosis based on quantitative data and SCM practitioners’ holistic diagnostic processes. Although the diagnostic accuracy was not great, it is noted that the proposed diagnostic model represents common rules among practitioners who have various points of view. Our results are expected to contribute as a desirable research guide for objective diagnosis in traditional medicine, as well as to contribute to the precise diagnosis of SC types in an objective manner in clinical practice. PMID:22762505

Diagnostic microbiology in veterinary dermatology: present and future.

PubMed

Guardabassi, Luca; Damborg, Peter; Stamm, Ivonne; Kopp, Peter A; Broens, Els M; Toutain, Pierre-Louis

2017-02-01

The microbiology laboratory can be perceived as a service provider rather than an integral part of the healthcare team. The aim of this review is to discuss the current challenges of providing a state-of-the-art diagnostic veterinary microbiology service including the identification (ID) and antimicrobial susceptibility testing (AST) of key pathogens in veterinary dermatology. The Study Group for Veterinary Microbiology (ESGVM) of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) identified scientific, technological, educational and regulatory issues impacting the predictive value of AST and the quality of the service offered by microbiology laboratories. The advent of mass spectrometry has significantly reduced the time required for ID of key pathogens such as Staphylococcus pseudintermedius. However, the turnaround time for validated AST methods has remained unchanged for many years. Beyond scientific and technological constraints, AST methods are not harmonized and clinical breakpoints for some antimicrobial drugs are either missing or inadequate. Small laboratories, including in-clinic laboratories, are usually not adequately equipped to run up-to-date clinical microbiologic diagnostic tests. ESGVM recommends the use of laboratories employing mass spectrometry for ID and broth micro-dilution for AST, and offering assistance by expert microbiologists on pre- and post-analytical issues. Setting general standards for veterinary clinical microbiology, promoting antimicrobial stewardship, and the development of new, validated and rapid diagnostic methods, especially for AST, are among the missions of ESGVM. © 2017 The Authors. Veterinary Dermatology published by John Wiley & Sons Ltd on behalf of the ESVD and ACVD.

Squash preparation: A reliable diagnostic tool in the intraoperative diagnosis of central nervous system tumors

PubMed Central

Mitra, Sumit; Kumar, Mohan; Sharma, Vivek; Mukhopadhyay, Debasis

2010-01-01

Background: Intraoperative cytology is an important diagnostic modality improving on the accuracy of the frozen sections. It has shown to play an important role especially in the intraoperative diagnosis of central nervous system tumors. Aim: To study the diagnostic accuracy of squash preparation and frozen section (FS) in the intraoperative diagnosis of central nervous system (CNS) tumors. Materials and Methods: This prospective study of 114 patients with CNS tumors was conducted over a period of 18 months (September 2004 to February 2006). The cytological preparations were stained by the quick Papanicolaou method. The squash interpretation and FS diagnosis were later compared with the paraffin section diagnosis. Results: Of the 114 patients, cytological diagnosis was offered in 96 cases. Eighteen nonneoplastic or noncontributory cases were excluded. Using hematoxylin and eosin-stained histopathology sections as the gold standard, the diagnostic accuracy of cytology was 88.5% (85/96) and the accuracy on FS diagnosis was 90.6% (87/96). Among these cases, gliomas formed the largest category of tumors (55.2%). The cytological accuracy in this group was 84.9% (45/53) and the comparative FS figure was 86.8% (46/53). In cases where the smear and the FS diagnosis did not match, the latter opinion was offered. Conclusions: Squash preparation is a reliable, rapid and easy method and can be used as a complement to FS in the intraoperative diagnosis of CNS tumors. PMID:21187881

Differential white cell count by centrifugal microfluidics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generationmore » of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.« less

Performance evaluation of direct saline stool microscopy, Formol ether concentration and Kato Katz diagnostic methods for intestinal parasitosis in the absence of gold standard methods.

PubMed

Hailu, Tadesse; Abera, Bayeh

2015-07-01

The parasite load within the sample and the amount of sample taken during examination greatly compromise the sensitivity of direct saline stool microscopy. A cross-sectional study was conducted in March 2011 in Bahir Dar city among 778 fresh single stool samples to evaluate the performance of direct saline (DS), Kato Katz (KK) and Formol ether concentration (FEC) methods against the 'Gold' standard. Among 778 stool samples from school age children, the highest prevalence of intestinal parasites was recorded by FEC (55.1%). The sensitivity of DS, FEC and KK were 61.1%, 92.3% and 58.7%, respectively. FEC is more sensitive than DS and KK. Hence, use of the latter is preferred. © The Author(s) 2015.

Research Diagnostic Criteria for Temporomandibular Disorders: Validity of Axis I Diagnoses

PubMed Central

Truelove, Edmond; Pan, Wei; Look, John O.; Mancl, Lloyd A.; Ohrbach, Richard K.; Velly, Ana; Huggins, Kimberly; Lenton, Patricia; Schiffman, Eric L.

2011-01-01

AIMS To estimate the criterion validity of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I TMD diagnoses. METHODS A combined total of 614 TMD community and clinic cases and 91 controls were examined at 3 study sites. RDC/TMD Axis I diagnoses were algorithmically derived from an examination performed by calibrated dental hygienists. Reference standards (Gold Standards) were established by means of consensus diagnoses rendered by 2 TMD experts using all available clinical data, including imaging studies. Validity of the RDC/TMD Axis I TMD diagnoses was estimated relative to reference-standard diagnoses (gold standard diagnoses). Target sensitivity and specificity were set a priori at ≥ 0.70 and ≥ 0.95, respectively. RESULTS Target sensitivity and specificity were not observed for any of the 8 RDC/TMD diagnoses. The highest validity was achieved for Group Ia myofascial pain (sensitivity 0.65, specificity 0.92) and Group Ib myofascial pain with limited opening (sensitivity 0.79, specificity 0.92). Target sensitivity and specificity were observed only when both Group I diagnoses were combined (0.87 and 0.98, respectively). For Group II (disc displacements) and Group III (arthralgia, arthritis, arthrosis) diagnoses, all estimates for sensitivity were below target (0.03 to 0.53), and specificity ranged from below to on target (0.86 to 0.99). CONCLUSION The RDC/TMD Axis I TMD diagnoses did not reach the targets set at sensitivity of ≥ 0.70 and specificity of ≥ 0.95. Target validity was obtained only for myofascial pain without differentiation between normal and limited opening. Revision of the current Axis I TMD diagnostic algorithms is warranted to improve their validity. PMID:20213030

The 2014 updated version of the Confusion Assessment Method for the Intensive Care Unit compared to the 5th version of the Diagnostic and Statistical Manual of Mental Disorders and other current methods used by intensivists.

PubMed

Chanques, Gérald; Ely, E Wesley; Garnier, Océane; Perrigault, Fanny; Eloi, Anaïs; Carr, Julie; Rowan, Christine M; Prades, Albert; de Jong, Audrey; Moritz-Gasser, Sylvie; Molinari, Nicolas; Jaber, Samir

2018-03-01

One third of patients admitted to an intensive care unit (ICU) will develop delirium. However, delirium is under-recognized by bedside clinicians without the use of delirium screening tools, such as the Intensive Care Delirium Screening Checklist (ICDSC) or the Confusion Assessment Method for the ICU (CAM-ICU). The CAM-ICU was updated in 2014 to improve its use by clinicians throughout the world. It has never been validated compared to the new reference standard, the Diagnostic and Statistical Manual of Mental Disorders 5th version (DSM-5). We made a prospective psychometric study in a 16-bed medical-surgical ICU of a French academic hospital, to measure the diagnostic performance of the 2014 updated CAM-ICU compared to the DSM-5 as the reference standard. We included consecutive adult patients with a Richmond Agitation Sedation Scale (RASS) ≥ -3, without preexisting cognitive disorders, psychosis or cerebral injury. Delirium was independently assessed by neuropsychological experts using an operationalized approach to DSM-5, by investigators using the CAM-ICU and the ICDSC, by bedside clinicians and by ICU patients. The sensitivity, specificity, positive and negative predictive values were calculated considering neuropsychologist DSM-5 assessments as the reference standard (primary endpoint). CAM-ICU inter-observer agreement, as well as that between delirium diagnosis methods and the reference standard, was summarized using κ coefficients, which were subsequently compared using the Z-test. Delirium was diagnosed by experts in 38% of the 108 patients included for analysis. The CAM-ICU had a sensitivity of 83%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 91%. Compared to the reference standard, the CAM-ICU had a significantly (p < 0.05) higher agreement (κ = 0.86 ± 0.05) than the physicians,' residents' and nurses' diagnoses (κ = 0.65 ± 0.09; 0.63 ± 0.09; 0.61 ± 0.09, respectively), as well as the patient's own impression of feeling delirious (κ = 0.02 ± 0.11). Differences between the ICDSC (κ = 0.69 ± 0.07) and CAM-ICU were not significant (p = 0.054). The CAM-ICU demonstrated a high reliability for inter-observer agreement (κ = 0.87 ± 0.06). The 2014 updated version of the CAM-ICU is valid according to DSM-5 criteria and reliable regarding inter-observer agreement in a research setting. Delirium remains under-recognized by bedside clinicians.

Polymerase chain reaction: A molecular diagnostic tool in periodontology

PubMed Central

Maheaswari, Rajendran; Kshirsagar, Jaishree Tukaram; Lavanya, Nallasivam

2016-01-01

This review discusses the principles of polymerase chain reaction (PCR) and its application as a diagnostic tool in periodontology. The relevant MEDLINE and PubMed indexed journals were searched manually and electronically by typing PCR, applications of PCR, PCR in periodontics, polymorphism studies in periodontitis, and molecular techniques in periodontology. The searches were limited to articles in English language and the articles describing PCR process and its relation to periodontology were collected and used to prepare a concise review. PCR has now become a standard diagnostic and research tool in periodontology. Various studies reveal that its sensitivity and specificity allow it as a rapid, efficient method of detecting, identifying, and quantifying organism. Different immune and inflammatory markers can be identified at the mRNA expression level, and also the determination of genetic polymorphisms, thus providing the deeper insight into the mechanisms underlying the periodontal disease. PMID:27143822

The role of flow cytometry in companion animal diagnostic medicine.

PubMed

Tarrant, Jacqueline M

2005-11-01

Flow cytometry is a powerful tool for characterising the composition of complex cell populations. The accuracy and precision of this technology for describing and enumerating cells exceeds traditional methods. The number of diagnostic veterinary laboratories with access to a dedicated machine is increasing, and there is the potential to offer a clinical flow cytometry service. The improved availability of monoclonal antibodies (mAb) to cell markers expressed by the leukocytes of companion animals, permits the implementation of comprehensive mAb panels suitable for diagnosis of lympho- and myeloproliferative disease. Reticulated erythrocyte and platelet quantification, antiglobulin assays for immune-mediated cytopenias, lymphocyte subset analysis, and immunophenotyping of lymphoma and leukemia, have been validated for companion animal samples on the flow cytometer. It is now timely to consider the role of flow cytometry in diagnostic practice, and the requirement for quality assurance and standardization of testing procedures.

Polymerase chain reaction: A molecular diagnostic tool in periodontology.

PubMed

Maheaswari, Rajendran; Kshirsagar, Jaishree Tukaram; Lavanya, Nallasivam

2016-01-01

This review discusses the principles of polymerase chain reaction (PCR) and its application as a diagnostic tool in periodontology. The relevant MEDLINE and PubMed indexed journals were searched manually and electronically by typing PCR, applications of PCR, PCR in periodontics, polymorphism studies in periodontitis, and molecular techniques in periodontology. The searches were limited to articles in English language and the articles describing PCR process and its relation to periodontology were collected and used to prepare a concise review. PCR has now become a standard diagnostic and research tool in periodontology. Various studies reveal that its sensitivity and specificity allow it as a rapid, efficient method of detecting, identifying, and quantifying organism. Different immune and inflammatory markers can be identified at the mRNA expression level, and also the determination of genetic polymorphisms, thus providing the deeper insight into the mechanisms underlying the periodontal disease.

Noninvasive Brain Stimulation in Pediatric ADHD: A Review

PubMed Central

Rubio, Belen; Boes, Aaron D.; Laganiere, Simon; Rotenberg, Alexander; Jeurissen, Danique; Pascual-Leone, Alvaro

2015-01-01

Attention-deficit hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in the pediatric population. The clinical management of ADHD is currently limited by a lack of reliable diagnostic biomarkers and inadequate therapy for a minority of patients that do not respond to standard pharmacotherapy. There is optimism that noninvasive brain stimulation may help to address these limitations. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are two methods of noninvasive brain stimulation that modulate cortical excitability and brain network activity. TMS can be used diagnostically to probe cortical neurophysiology, while daily use of repetitive TMS or tDCS can induce long-lasting and potentially therapeutic changes in targeted networks. In this review we highlight research showing the potential diagnostic and therapeutic applications of TMS and tDCS in pediatric ADHD. We also discuss the safety and ethics of using these tools in the pediatric population. PMID:26661481

Elucidating the Mechanism of p27 Inactivation by the Bcr-Abl Tyrosine Kinase

DTIC Science & Technology

2005-10-01

Grants 2002- Leukemia Research Fund Membership in Scientific Committees 2000- Molecular diagnostics (German competence network acute...transplantation, including reduced intensity conditioning. Hematological Diagnostics Standard morphology. Supervised molecular diagnostics in the

Diagnostic digital cytopathology: Are we ready yet?

PubMed Central

House, Jarret C.; Henderson-Jackson, Evita B.; Johnson, Joseph O.; Lloyd, Mark C.; Dhillon, Jasreman; Ahmad, Nazeel; Hakam, Ardeshir; Khalbuss, Walid E.; Leon, Marino E.; Chhieng, David; Zhang, Xiaohui; Centeno, Barbara A.; Bui, Marilyn M.

2013-01-01

Background: The cytology literature relating to diagnostic accuracy using whole slide imaging is scarce. We studied the diagnostic concordance between glass and digital slides among diagnosticians with different profiles to assess the readiness of adopting digital cytology in routine practice. Materials and Methods: This cohort consisted of 22 de-identified previously screened and diagnosed cases, including non-gynecological and gynecological slides using standard preparations. Glass slides were digitalized using Aperio ScanScope XT (×20 and ×40). Cytopathologists with (3) and without (3) digital experience, cytotechnologists (4) and senior pathology residents (2) diagnosed the digital slides independently first and recorded the results. Glass slides were read and recorded separately 1-3 days later. Accuracy of diagnosis, time to diagnosis and diagnostician's profile were analyzed. Results: Among 22 case pairs and four study groups, correct diagnosis (93% vs. 86%) was established using glass versus digital slides. Both methods more (>95%) accurately diagnosed positive cases than negatives. Cytopathologists with no digital experience were the most accurate in digital diagnosis, even the senior members. Cytotechnologists had the fastest diagnosis time (3 min/digital vs. 1.7 min/glass), but not the best accuracy. Digital time was 1.5 min longer than glass-slide time/per case for cytopathologists and cytotechnologists. Senior pathology residents were slower and less accurate with both methods. Cytopathologists with digital experience ranked 2nd fastest in time, yet last in accuracy for digital slides. Conclusions: There was good overall diagnostic agreement between the digital whole-slide images and glass slides. Although glass slide diagnosis was more accurate and faster, the results of technologists and pathologists with no digital cytology experience suggest that solid diagnostic ability is a strong indicator for readiness of digital adoption. PMID:24392242

Diagnostic work-up and loss of tuberculosis suspects in Jogjakarta, Indonesia

PubMed Central

2012-01-01

Background Early and accurate diagnosis of pulmonary tuberculosis (TB) is critical for successful TB control. To assist in the diagnosis of smear-negative pulmonary TB, the World Health Organisation (WHO) recommends the use of a diagnostic algorithm. Our study evaluated the implementation of the national tuberculosis programme's diagnostic algorithm in routine health care settings in Jogjakarta, Indonesia. The diagnostic algorithm is based on the WHO TB diagnostic algorithm, which had already been implemented in the health facilities. Methods We prospectively documented the diagnostic work-up of all new tuberculosis suspects until a diagnosis was reached. We used clinical audit forms to record each step chronologically. Data on the patient's gender, age, symptoms, examinations (types, dates, and results), and final diagnosis were collected. Results Information was recorded for 754 TB suspects; 43.5% of whom were lost during the diagnostic work-up in health centres, 0% in lung clinics. Among the TB suspects who completed diagnostic work-ups, 51.1% and 100.0% were diagnosed without following the national TB diagnostic algorithm in health centres and lung clinics, respectively. However, the work-up in the health centres and lung clinics generally conformed to international standards for tuberculosis care (ISTC). Diagnostic delays were significantly longer in health centres compared to lung clinics. Conclusions The high rate of patients lost in health centres needs to be addressed through the implementation of TB suspect tracing and better programme supervision. The national TB algorithm needs to be revised and differentiated according to the level of care. PMID:22333111

3 Tesla breast MR imaging as a problem-solving tool: Diagnostic performance and incidental lesions

PubMed Central

Spick, Claudio; Szolar, Dieter H. M.; Preidler, Klaus W.; Reittner, Pia; Rauch, Katharina; Brader, Peter; Tillich, Manfred

2018-01-01

Purpose To investigate the diagnostic performance and incidental lesion yield of 3T breast MRI if used as a problem-solving tool. Methods This retrospective, IRB-approved, cross-sectional, single-center study comprised 302 consecutive women (mean: 50±12 years; range: 20–79 years) who were undergoing 3T breast MRI between 03/2013-12/2014 for further workup of conventional and clinical breast findings. Images were read by experienced, board-certified radiologists. The reference standard was histopathology or follow-up ≥ two years. Sensitivity, specificity, PPV, and NPV were calculated. Results were stratified by conventional and clinical breast findings. Results The reference standard revealed 53 true-positive, 243 true-negative, 20 false-positive, and two false-negative breast MRI findings, resulting in a sensitivity, specificity, PPV, and NPV of 96.4% (53/55), 92.4% (243/263), 72.6% (53/73), and 99.2% (243/245), respectively. In 5.3% (16/302) of all patients, incidental MRI lesions classified BI-RADS 3–5 were detected, 37.5% (6/16) of which were malignant. Breast composition and the imaging findings that had led to referral had no significant influence on the diagnostic performance of breast MR imaging (p>0.05). Conclusion 3T breast MRI yields excellent diagnostic results if used as a problem-solving tool independent of referral reasons. The number of suspicious incidental lesions detected by MRI is low, but is associated with a substantial malignancy rate. PMID:29293582

MPT64 antigen detection test improves routine diagnosis of extrapulmonary tuberculosis in a low-resource setting: A study from the tertiary care hospital in Zanzibar.

PubMed

Jørstad, Melissa Davidsen; Marijani, Msafiri; Dyrhol-Riise, Anne Ma; Sviland, Lisbet; Mustafa, Tehmina

2018-01-01

Extrapulmonary tuberculosis (EPTB) is a diagnostic challenge. An immunochemistry-based MPT64 antigen detection test (MPT64 test) has reported higher sensitivity in the diagnosis of EPTB compared with conventional methods. The objective of this study was to implement and evaluate the MPT64 test in routine diagnostics in a low-resource setting. Patients with presumptive EPTB were prospectively enrolled at Mnazi Mmoja Hospital, Zanzibar, and followed to the end of treatment. Specimens collected were subjected to routine diagnostics, GeneXpert® MTB/RIF assay and the MPT64 test. The performance of the MPT64 test was assessed using a composite reference standard, defining the patients as tuberculosis (TB) cases or non-TB cases. Patients (n = 132) were classified as confirmed TB (n = 12), probable TB (n = 34), possible TB (n = 18), non-TB (n = 62) and uncategorized (n = 6) cases. Overall, in comparison to the composite reference standard for diagnosis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the MPT64 test was 69%, 95%, 94%, 75% and 82%, respectively. The MPT64 test performance was best in TB lymphadenitis cases (n = 67, sensitivity 79%, specificity 97%) and in paediatric TB (n = 41, sensitivity 100%, specificity 96%). We show that the MPT64 test can be implemented in routine diagnostics in a low-resource setting and improves the diagnosis of EPTB, especially in TB lymphadenitis and in children.

Fear of Progression in Parents of Children with Cancer: Results of An Online Expert Survey in Pediatric Oncology.

PubMed

Clever, Katharina; Schepper, Florian; Küpper, Luise; Christiansen, Holger; Martini, Julia

2018-04-01

Fear of Progression (FoP) is a commonly reported psychological strain in parents of children with cancer. This expert survey investigates how professionals in pediatric oncology estimate the burden and consequences of FoP in parents and how they assess and treat parental FoP. N=77 professionals in pediatric oncology (members and associates of the Psychosocial Association in Paediatric Oncology and Haematology, PSAPOH) were examined in an online survey with a self-developed questionnaire. Data were analyzed via descriptive statistics and qualitative content analysis. Three of four experts in clinical practice were (very) often confronted with parental FoP which was associated with more negative (e. g., psychosomatic reactions, reduced family functioning) than positive (e. g., active illness processing) consequences. N=40 experts indicated that they mainly assess parents' anxiety via clinical judgment (72.5%) and/or according to ICD-10/DSM-5 diagnostic criteria (37.5%), whereas standardized methods such as psycho-oncological questionnaires (12.5%) were applied less often. Only n=6 experts named a specific diagnostic approach to assess parental FoP. The most common treatment approaches for FoP were supportive counseling (74.0%), psychotherapy (59.7%) and/or relaxation techniques (55.8%). Parental FoP is frequently perceived by experts in clinical practice. A standardized diagnostic procedure would increase comparability of diagnostic judgments and harmonize treatment indications. © Georg Thieme Verlag KG Stuttgart · New York.

Benefits and challenges of molecular diagnostics for childhood tuberculosis.

PubMed

Gutierrez, Cristina

2016-12-01

Expanding tuberculosis (TB)-diagnostic services, including access to rapid tests, is a World Health Organization (WHO) strategy to accelerate progress toward ending TB. Faster and more sensitive molecular tests capable of diagnosing TB and drug-resistant TB have the technical capacity to address limitations associated with smears and cultures by increasing accuracy and shortening turnaround times as compared with those of these conventional laboratory methods. Nucleic acid amplification assays used to detect and analyze Mycobacterium tuberculosis (MTB)-complex nucleic acids can be used directly on specimens from patients suspected of having TB. Recently, several commercial molecular tests were developed to detect MTB and determine the drug resistance (DR) based on detection of specific genetic mutations conferring resistance. The first to be endorsed by the WHO was molecular line-probe assay technology. This test uses polymerase chain reaction (PCR) and reverse-hybridization methods to rapidly identify MTB and DR-related mutations simultaneously. More recently, the WHO endorsed Xpert MTB/RIF, Cepheid Inc, CA, USA, a fully automated assay used for TB diagnosis that relies upon PCR techniques for detection of TB and rifampicin resistance-related mutations. Other promising molecular TB assays for simplifying PCR-based testing protocols and increasing their accuracy are under development and evaluation. Although we lack a practical gold standard for the diagnosis of childhood TB, its bacteriological confirmation is always recommended to be sought whenever possible prior to a diagnostic decision being made. Conventional diagnostic laboratory TB tests are less efficient for children as compared with adults, because sufficient sputum samples are more difficult to collect from infants and young children, and their disease is often paucibacillary, resulting in smear-negative disease. These inherent challenges associated with childhood TB are due to immunological- and pathophysiological-response differences relative to those observed in adults. Several recent meta-analyses showed low sensitivity estimates of PCR-based TB assays for paucibacillary forms of TB (extrapulmonary TB and smear-negative pulmonary disease), which represent the vast majority of childhood TB cases. Despite the lack of evidence regarding use of the rapid molecular assays to identify TB and detect DR in children, and due to the clinical nature of childhood TB, TB-expert groups recommend including rapid methods for TB identification and DR detection in diagnostic algorithms for children suspected of both smear-positive and -negative pulmonary or extrapulmonary TB, both with or without human immunodeficiency virus (HIV)-coinfection, when combined with standard methods (including clinical, microbiological, and radiological assessment) for diagnosing active TB and conventional DR. Since 2011, the WHO has specifically recommended use of the Xpert MTB/RIF test as an initial diagnostic tool for children with suspected HIV-associated TB or multidrug-resistant TB based on successful treatment data related to adults. Implementation of the rapid molecular assays for rapid detection of TB and DR should occur in laboratories with proven capability to run molecular tests and where quality control systems are implemented. Molecular approaches should be more largely tested in children, given their status as the group in whom the diagnostic dilemma is most pronounced. These tests should also be included in specific childhood TB diagnostic algorithms adapted to the local/national context in combination with other strategies for improving diagnostics, including more effective specimen collection. Copyright © 2016.

The applicability of real-time PCR in the diagnostic of cutaneous leishmaniasis and parasite quantification for clinical management: Current status and perspectives.

PubMed

Moreira, Otacilio C; Yadon, Zaida E; Cupolillo, Elisa

2017-09-29

Cutaneous leishmaniasis (CL) is spread worldwide and is the most common manifestation of leishmaniasis. Diagnosis is performed by combining clinical and epidemiological features, and through the detection of Leishmania parasites (or DNA) in tissue specimens or trough parasite isolation in culture medium. Diagnosis of CL is challenging, reflecting the pleomorphic clinical manifestations of this disease. Skin lesions vary in severity, clinical appearance, and duration, and in some cases, they can be indistinguishable from lesions related to other diseases. Over the past few decades, PCR-based methods, including real-time PCR assays, have been developed for Leishmania detection, quantification and species identification, improving the molecular diagnosis of CL. This review provides an overview of many real-time PCR methods reported for the diagnostic evaluation of CL and some recommendations for the application of these methods for quantification purposes for clinical management and epidemiological studies. Furthermore, the use of real-time PCR for Leishmania species identification is also presented. The advantages of real-time PCR protocols are numerous, including increased sensitivity and specificity and simpler standardization of diagnostic procedures. However, despite the numerous assays described, there is still no consensus regarding the methods employed. Furthermore, the analytical and clinical validation of CL molecular diagnosis has not followed international guidelines so far. A consensus methodology comprising a DNA extraction protocol with an exogenous quality control and an internal reference to normalize parasite load is still needed. In addition, the analytical and clinical performance of any consensus methodology must be accurately assessed. This review shows that a standardization initiative is essential to guide researchers and clinical laboratories towards the achievement of a robust and reproducible methodology, which will permit further evaluation of parasite load as a surrogate marker of prognosis and monitoring of aetiological treatment, particularly in multi-centric observational studies and clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

Technical Note: Method to correlate whole-specimen histopathology of radical prostatectomy with diagnostic MR imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGrath, Deirdre M., E-mail: d.mcgrath@sheffield.ac.uk; Lee, Jenny; Foltz, Warren D.

Purpose: Validation of MRI-guided tumor boundary delineation for targeted prostate cancer therapy is achieved via correlation with gold-standard histopathology of radical prostatectomy specimens. Challenges to accurate correlation include matching the pathology sectioning plane with the in vivo imaging slice plane and correction for the deformation that occurs between in vivo imaging and histology. A methodology is presented for matching of the histological sectioning angle and position to the in vivo imaging slices. Methods: Patients (n = 4) with biochemical failure following external beam radiotherapy underwent diagnostic MRI to confirm localized recurrence of prostate cancer, followed by salvage radical prostatectomy. High-resolutionmore » 3-D MRI of the ex vivo specimens was acquired to determine the pathology sectioning angle that best matched the in vivo imaging slice plane, using matching anatomical features and implanted fiducials. A novel sectioning device was developed to guide sectioning at the correct angle, and to assist the insertion of reference dye marks to aid in histopathology reconstruction. Results: The percentage difference in the positioning of the urethra in the ex vivo pathology sections compared to the positioning in in vivo images was reduced from 34% to 7% through slicing at the best match angle. Reference dye marks were generated, which were visible in ex vivo imaging, in the tissue sections before and after processing, and in histology sections. Conclusions: The method achieved an almost fivefold reduction in the slice-matching error and is readily implementable in combination with standard MRI technology. The technique will be employed to generate datasets for correlation of whole-specimen prostate histopathology with in vivo diagnostic MRI using 3-D deformable registration, allowing assessment of the sensitivity and specificity of MRI parameters for prostate cancer. Although developed specifically for prostate, the method is readily adaptable to other types of whole tissue specimen, such as mastectomy or liver resection.« less

Diagnostic procedures in tularaemia with special focus on molecular and immunological techniques.

PubMed

Splettstoesser, W D; Tomaso, H; Al Dahouk, S; Neubauer, H; Schuff-Werner, P

2005-08-01

Tularaemia is a severe bacterial zoonosis caused by the highly infectious agent Francisella tularensis. It is endemic in countries of the northern hemisphere ranging from North America to Europe, Asia and Japan. Very recently, Francisella-like strains causing disease in humans were described from tropical northern Australia. In the last decade, efforts have been made to develop sensitive and specific immunological and molecular techniques for the laboratory diagnosis of tularaemia and also for the definite identification of members of the species F. tularensis and its four subspecies. Screening for the keyword 'Francisella' a Medline search over the last decade was performed and articles describing diagnostic methods for tularaemia and its causative agent were selected. Besides classical microbiological techniques (cultivation, biochemical profiling, susceptibility testing) several new immunological and molecular approaches to identify F. tularensis have been introduced employing highly specific antibodies and various polymerase chain reaction (PCR)-based methods. Whereas direct antigen detection by enzyme-linked immunosorbent assay (ELISA) or immunofluorescence might allow early presumptive diagnosis of tularaemia, these methods--like all PCR techniques--still await further evaluation. Therefore, diagnosis of tularaemia still relies mainly on the demonstration of specific antibodies in the host. ELISA and immunoblot methods started to replace the standard tube or micro-agglutination assays. However, the diagnostic value of antibody detection in the very early clinical phase of tularaemia is limited. Francisella tularensis is regarded as a 'highest priority' biological agent (category 'A' according to the CDC, Atlanta, GA, USA), thus rapid and reliable diagnosis of tularaemia is required not only for a timely onset of therapy, the handling of outbreak investigations but also for the surveillance of endemic foci. Only very recently, evaluated test kits for serological diagnosis of human tularaemia became available, while the introduction of standardized molecular techniques for detection and typing is still missing.

Glucose-6-phosphate dehydrogenase laboratory assay: How, when, and why?

PubMed

Minucci, Angelo; Giardina, Bruno; Zuppi, Cecilia; Capoluongo, Ettore

2009-01-01

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common defect of red blood cells. Although some different laboratory techniques or methods are employed for the biochemical screening, a strict relationship between biochemists, clinicians, and molecular biologists is necessary for a definitive diagnosis. This article represents an overview on the current laboratory tests finalized to the screening or to the definitive diagnosis of G6PD-deficiency, underlying the problems regarding the biochemical and molecular identification of heterozygote females other than those regarding the standardization of the clinical and laboratory diagnostic procedures. Finally, this review is aimed to give a flow-chart for the complete diagnostic approach of G6PD-deficiency.

Cutting Edge Methods for Non-Invasive Disease Diagnosis Using E-Tongue and E-Nose Devices

PubMed Central

Fitzgerald, Jessica

2017-01-01

Biomimetic cross-reactive sensor arrays (B-CRSAs) have been used to detect and diagnose a wide variety of diseases including metabolic disorders, mental health diseases, and cancer by analyzing both vapor and liquid patient samples. Technological advancements over the past decade have made these systems selective, sensitive, and affordable. To date, devices for non-invasive and accurate disease diagnosis have seen rapid improvement, suggesting a feasible alternative to current standards for medical diagnostics. This review provides an overview of the most recent B-CRSAs for diagnostics (also referred to electronic noses and tongues in the literature) and an outlook for future technological development. PMID:29215588

Recommendations for accreditation of laboratories in molecular biology of hematologic malignancies.

PubMed

Flandrin-Gresta, Pascale; Cornillet, Pascale; Hayette, Sandrine; Gachard, Nathalie; Tondeur, Sylvie; Mauté, Carole; Cayuela, Jean-Michel

2015-01-01

Over recent years, the development of molecular biology techniques has improved the hematological diseases diagnostic and follow-up. Consequently, these techniques are largely used in the biological screening of these diseases; therefore the Hemato-oncology molecular diagnostics laboratories must be actively involved in the accreditation process according the ISO 15189 standard. The French group of molecular biologists (GBMHM) provides requirements for the implementation of quality assurance for the medical molecular laboratories. This guideline states the recommendations for the pre-analytical, analytical (methods validation procedures, quality controls, reagents), and post-analytical conditions. In addition, herein we state a strategy for the internal quality control management. These recommendations will be regularly updated.

Combining PCR with Microscopy to Reduce Costs of Laboratory Diagnosis of Buruli Ulcer

PubMed Central

Yeboah-Manu, Dorothy; Asante-Poku, Adwoa; Asan-Ampah, Kobina; Ampadu, Emelia Danso Edwin; Pluschke, Gerd

2011-01-01

The introduction of antibiotic therapy as first-line treatment of Buruli ulcer underlines the importance of laboratory confirmation of clinical diagnosis. Because smear microscopy has very limited sensitivity, the technically demanding and more expensive IS2404 diagnostic polymerase chain reaction (PCR) has become the main method for confirmation. By optimization of the release of mycobacteria from swab specimen and concentration of bacterial suspensions before smearing, we were able to improve the detection rate of acid-fast bacilli by microscopy after Ziehl–Neelsen staining. Compared with IS2404 PCR, which is the gold standard diagnostic method, the sensitivity and specificity of microscopy with 100 concentrated specimens were 58.4% and 95.7%, respectively. We subsequently evaluated a stepwise laboratory confirmation algorithm with detection of AFB as first-line method and IS2404 PCR performed only with those samples that were negative in microscopic analysis. This stepwise approach reduced unit cost by more than 50% to $5.41, and the total costs were reduced from $917 to $433. PMID:22049046

Improved localisation of neoclassical tearing modes by combining multiple diagnostic estimates

NASA Astrophysics Data System (ADS)

Rapson, C. J.; Fischer, R.; Giannone, L.; Maraschek, M.; Reich, M.; Treutterer, W.; The ASDEX Upgrade Team

2017-07-01

Neoclassical tearing modes (NTMs) strongly degrade confinement in tokamaks, and are a leading cause of disruptions. They can be stabilised by targeted electron cyclotron current drive (ECCD), however the effectiveness of ECCD depends strongly on the accuracy or misalignment between ECCD and the NTM. The first step to ensure minimal misalignment is a good estimate of the NTM location. In previous NTM control experiments, three methods have been used independently to estimate the NTM location: the magnetic equilibrium, correlation between magnetic and spatially-resolved temperature fluctuations, and the amplitude response of the NTM to nearby ECCD. This submission describes an algorithm which has been designed to fuse these three estimates into one, taking into account many of the characteristics of each diagnostic. Although the method diverges from standard data fusion methods, results from simulation and experiment confirm that the algorithm achieves its stated goal of providing an estimate that is more reliable and accurate than any of the individual estimates.

[Physical, chemical and morphological urine examination guidelines for the Analytical Phase from the Intersociety Urinalysis Group].

PubMed

Manoni, Fabio; Gessoni, Gianluca; Fogazzi, Giovanni Battista; Alessio, Maria Grazia; Caleffi, Alberta; Gambaro, Giovanni; Epifani, Maria Grazia; Pieretti, Barbara; Perego, Angelo; Ottomano, Cosimo; Saccani, Graziella; Valverde, Sara; Secchiero, Sandra

2016-01-01

With these guidelines the Intersociety Urinalysis Group (GIAU) aims to stimulate the following aspects: Improvement and standardization of the analytical approach to physical, chemical and morphological urine examination (ECMU). Improvement of the chemical analysis of urine with particular regard to the reconsideration of the diagnostic significance of the parameters that are traditionally evaluated in dipstick analysis together with an increasing awareness of the limits of sensitivity and specificity of this analytical method. Increase the awareness of the importance of professional skills in the field of urinary morphology and the relationship with the clinicians. Implement a policy of evaluation of the analytical quality by using, in addition to traditional internal and external controls, a program for the evaluation of morphological competence. Stimulate the diagnostics industry to focus research efforts and development methodology and instrumental catering on the needs of clinical diagnosis. The hope is to revalue the enormous diagnostic potential of 'ECMU, implementing a urinalysis on personalized diagnostic needs for each patient. Emphasize the value added to ECMU by automated analyzers for the study of the morphology of the corpuscular fraction urine. The hope is to revalue the enormous potential diagnostic of 'ECMU, implementing a urinalysis on personalized diagnostic needs that each patient brings with it.

Molecular Diagnostics in Transfusion Medicine: In Capillary, on a Chip, in Silico, or in Flight?

PubMed Central

Garritsen, Henk S.P.; Xiu-Cheng Fan, Alex; Lenz, Daniela; Hannig, Horst; Yan Zhong, Xiao; Geffers, Robert; Lindenmaier, Werner; Dittmar, Kurt E.J.; Wörmann, Bernhard

2009-01-01

Summary Serology, defined as antibody-based diagnostics, has been regarded as the diagnostic gold standard in transfusion medicine. Nowadays however the impact of molecular diagnostics in transfusion medicine is rapidly growing. Molecular diagnostics can improve tissue typing (HLA typing), increase safety of blood products (NAT testing of infectious diseases), and enable blood group typing in difficult situations (after transfusion of blood products or prenatal non-invasive RhD typing). Most of the molecular testing involves the determination of the presence of single nucleotide polymorphisms (SNPs). Antigens (e.g. blood group antigens) mostly result from single nucleotide differences in critical positions. However, most blood group systems cannot be determined by looking at a single SNP. To identify members of a blood group system a number of critical SNPs have to be taken into account. The platforms which are currently used to perform molecular diagnostics are mostly gel-based, requiring time-consuming multiple manual steps. To implement molecular methods in transfusion medicine in the future the development of higher-throughput SNP genotyping non-gel-based platforms which allow a rapid, cost-effective screening are essential. Because of its potential for automation, high throughput and cost effectiveness the special focus of this paper is a relative new technique: SNP genotyping by MALDI-TOF MS analysis. PMID:21113259

Quantitation of 5-Methyltetrahydrofolate in Cerebrospinal Fluid Using Liquid Chromatography-Electrospray Tandem Mass Spectrometry.

PubMed

Arning, Erland; Bottiglieri, Teodoro

2016-01-01

We describe a simple stable isotope dilution method for accurate and precise measurement of cerebrospinal fluid (CSF) 5-methyltetrahydrofolate (5-MTHF) as a clinical diagnostic test. 5-MTHF is the main biologically active form of folic acid and is involved in regulation of homocysteine and DNA synthesis. Measurement of 5-MTHF in CSF provides diagnostic information regarding diseases affecting folate metabolism within the central nervous system, in particular inborn errors of folate metabolism. Determination of 5-MTHF in CSF (50 μL) was performed utilizing high performance liquid chromatography coupled with electrospray positive ionization tandem mass spectrometry (HPLC-ESI-MS/MS). 5-MTHF in CSF is determined by a 1:2 dilution with internal standard (5-MTHF-(13)C5) and injected directly onto the HPLC-ESI-MS/MS system. Each assay is quantified using a five-point standard curve (25-400 nM) and has an analytical measurement range of 3-1000 nM.

High-level intuitive features (HLIFs) for intuitive skin lesion description.

PubMed

Amelard, Robert; Glaister, Jeffrey; Wong, Alexander; Clausi, David A

2015-03-01

A set of high-level intuitive features (HLIFs) is proposed to quantitatively describe melanoma in standard camera images. Melanoma is the deadliest form of skin cancer. With rising incidence rates and subjectivity in current clinical detection methods, there is a need for melanoma decision support systems. Feature extraction is a critical step in melanoma decision support systems. Existing feature sets for analyzing standard camera images are comprised of low-level features, which exist in high-dimensional feature spaces and limit the system's ability to convey intuitive diagnostic rationale. The proposed HLIFs were designed to model the ABCD criteria commonly used by dermatologists such that each HLIF represents a human-observable characteristic. As such, intuitive diagnostic rationale can be conveyed to the user. Experimental results show that concatenating the proposed HLIFs with a full low-level feature set increased classification accuracy, and that HLIFs were able to separate the data better than low-level features with statistical significance. An example of a graphical interface for providing intuitive rationale is given.

WE-A-210-00: Educational: Diagnostic Ultrasound QA

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This presentation will focus on the present role of ultrasound medical physics in clinical practices. The first part of the presentation will provide an overview of ultrasound QC methodologies and testing procedures. A brief review of ultrasound phantoms utilized in these testing procedures will be presented. The second part of the presentation will summarize ultrasound imaging technical standards and professional guidelines by American College of Radiology (ACR), American Institute of Ultrasound in Medicine (AIUM), American Association of Physicists in Medicine (AAPM) and International Electrotechnical Commission (IEC). The current accreditation requirements by ACR and AIUM for ultrasound practices will be describedmore » and the practical aspects of implementing QC programs to be compliant with these requirements will be discussed. Learning Objectives: Achieve familiarity with common ultrasound QC test methods and ultrasound phantoms. Understand the coverage of the existing testing standards and professional guidelines on diagnostic ultrasound imaging. Learn what a medical physicist needs to know about ultrasound program accreditation and be able to implement ultrasound QC programs accordingly.« less

Inadequate Diagnostic Evaluation in Young Patients Registered with a Diagnosis of Dementia: A Nationwide Register-Based Study

PubMed Central

Salem, Lise Cronberg; Andersen, Birgitte Bo; Nielsen, T. Rune; Stokholm, Jette; Jørgensen, Martin Balslev; Waldemar, Gunhild

2014-01-01

Background Establishing a diagnosis of dementia in young patients may be complex and have significant implications for the patient. The aim of this study was to evaluate the quality of the diagnostic work-up in young patients diagnosed with dementia in the clinical routine. Methods Two hundred patients were randomly selected from 891 patients aged ≤65 years registered with a diagnosis of dementia for the first time in 2008 in Danish hospitals, and 159 medical records were available for review. Three raters evaluated their medical records for the completeness of the diagnostic work-up on which the diagnosis of dementia had been based, using evidence-based guidelines for the diagnostic evaluation of dementia as reference standards. Results According to the rater review, only 111 (70%) patients met the clinical criteria for dementia. An acceptable diagnostic work-up including all items of recommended basic diagnostic evaluation was performed in only 24%, although more often (28%) in the subgroup of patients where dementia was confirmed by raters. Conclusion This first nationwide study of unselected young patients registered with a diagnosis of dementia indicated that the concept of dementia may be misinterpreted by clinicians and that a diagnosis of dementia in the young is only rarely based on a complete basic diagnostic work-up, calling for increased competency. PMID:24711812

A gold standard method for the evaluation of antibody-based materials functionality: Approach to forced degradation studies.

PubMed

Coussot, Gaëlle; Le Postollec, Aurélie; Faye, Clément; Dobrijevic, Michel

2018-04-15

The scope of this paper is to present a gold standard method to evaluate functional activity of antibody (Ab)-based materials during the different phases of their development, after their exposure to forced degradations or even during routine quality control. Ab-based materials play a central role in the development of diagnostic devices, for example, for screening or therapeutic target characterization, in formulation development, and in novel micro(nano)technology approaches to develop immunosensors useful for the analysis of trace substances in pharmaceutical and food industries, clinical and environmental fields. A very important aspect in diagnostic device development is the construction of its biofunctional surfaces. These Ab surfaces require biocompatibility, homogeneity, stability, specificity and functionality. Thus, this work describes the validation and applications of a unique ligand binding assay to directly perform the quantitative measurement of functional Ab binding sites immobilized on the solid surfaces. The method called Antibody Anti-HorseRadish Peroxidase (A2HRP) method, uses a covalently coated anti-HRP antibody (anti-HRP Ab) and does not need for a secondary Ab during the detection step. The A2HRP method was validated and gave reliable results over a wide range of absorbance values. Analyzed validation criteria were fulfilled as requested by the food and drug administration (FDA) and European Medicines Agency (EMA) guidance for the validation of bioanalytical methods with 1) an accuracy mean value within +15% of the nominal value; 2) the within-assay precision less than 7.1%, and 3) the inter-day variability under 12.1%. With the A2HRP method, it is then possible to quantify from 0.04 × 10 12 to 2.98 × 10 12 functional Ab binding sites immobilized on the solid surfaces. A2HRP method was validated according to FDA and EMA guidance, allowing the creation of a gold standard method to evaluate Ab surfaces for their resistance under laboratory constraints. Stability testing was described through forced degradation studies after exposure of Ab-surfaces to storage, pH and aqueous-organic solvent mixture stresses. Copyright © 2018 Elsevier B.V. All rights reserved.

Taenia solium metacestode preparation in rural areas of sub-Saharan Africa: a source for diagnosis and research on cysticercosis.

PubMed

Schmidt, V; Sikasunge, C S; Odongo-Aginya, E; Simukoko, C; Mwanjali, G; Alarakol, S; Ovuga, E; Matuja, W; Kihamia, C; Löscher, T; Winkler, A S; Bretzel, G

2015-03-01

Taenia solium metacestodes/cysts obtained from pig carcasses constitute a primary source for diagnostic tools used for the detection of human cysticercosis. Data on T. solium cyst preparation in Africa is still scarce but required to establish independent reference laboratories. The aim of the present study is a) to present the likely yield of T. solium cyst material by the use of two different preparation methods in the field and b) to investigate its suitability for immunodiagnosis of human cysticercosis. In Zambia, Uganda and Tanzania 670 pigs were screened for T. solium infection. Cysts were prepared by 'shaking method' and 'washing method'. Generated crude antigens were applied in a standard western blot assay. 46 out of 670 pigs (6.9%) were found positive for T. solium (Zambia: 12/367, 3.3%; Uganda: 11/217, 5.1%; Tanzania 23/86, 26.7%). Mean values of 77.7 ml whole cysts, 61.8 ml scolices/membranes and 10.9 ml cyst fluid were obtained per pig. Suitability of collected material for the use as crude antigen and molecular diagnostic techniques was demonstrated. This study clearly shows that T. solium cyst preparation in African settings by simple field methods constitutes an effective way to obtain high quality material as source for diagnostic tools and research purposes.

Impact of gene patents on diagnostic testing: a new patent landscaping method applied to spinocerebellar ataxia

PubMed Central

Berthels, Nele; Matthijs, Gert; Van Overwalle, Geertrui

2011-01-01

Recent reports in Europe and the United States raise concern about the potential negative impact of gene patents on the freedom to operate of diagnosticians and on the access of patients to genetic diagnostic services. Patents, historically seen as legal instruments to trigger innovation, could cause undesired side effects in the public health domain. Clear empirical evidence on the alleged hindering effect of gene patents is still scarce. We therefore developed a patent categorization method to determine which gene patents could indeed be problematic. The method is applied to patents relevant for genetic testing of spinocerebellar ataxia (SCA). The SCA test is probably the most widely used DNA test in (adult) neurology, as well as one of the most challenging due to the heterogeneity of the disease. Typically tested as a gene panel covering the five common SCA subtypes, we show that the patenting of SCA genes and testing methods and the associated licensing conditions could have far-reaching consequences on legitimate access to this gene panel. Moreover, with genetic testing being increasingly standardized, simply ignoring patents is unlikely to hold out indefinitely. This paper aims to differentiate among so-called ‘gene patents' by lifting out the truly problematic ones. In doing so, awareness is raised among all stakeholders in the genetic diagnostics field who are not necessarily familiar with the ins and outs of patenting and licensing. PMID:21811306

Novel rapid molecular diagnosis of fetal chromosomal abnormalities associated with recurrent pregnancy loss.

PubMed

Yang, Lan; Tang, Ye; Lu, Mudan; Yang, Yuefen; Xiao, Jianping; Wang, Qiaoxia; Yang, Canfeng; Tao, Hehua; Xiang, Jingying

2016-12-01

Labor-intensive karyotyping is used as the reference standard diagnostic test to identify copy number variants (CNVs) in the fetal genome after recurrent pregnancy loss. Our aim was to present and evaluate a novel molecular assay called CNVplex that could potentially be used as an alternative method to conventional karyotyping for diagnosing fetal chromosomal abnormalities associated with recurrent pregnancy loss. Using karyotyping as the reference standard, CNVplex was performed to identify fetal chromosomal abnormalities in the chorionic villus samples from 76 women experiencing at least two pregnancy losses. Its diagnostic accuracy, sensitivity, and specificity were evaluated to detect aneuploidies associated with recurrent pregnancy loss. Turnaround time and costs of CNVplex were also measured. Diagnostic accuracy of CNVplex in aneuploidies that are associated with recurrent pregnancy loss was 1.0 (95% CI 0.94-1.0), sensitivity was 100% (95% CI 0.89-1.0), and specificity was 100% (95% CI 0.875-1.0). Diagnostic accuracy of CNVplex was similar to that of karyotyping. Both karyotyping and CNVplex assay detected 27 autosomal trisomies, three 45,X monosomies, and three polyploidies. CNVplex also detected additional novel structural abnormalities of the fetal genome. Compared with karyotyping, CNVplex significantly (p = 0.001) reduced the waiting time by 13.98 days (95% CI 13.88-14.08) and the cost by US $241 (95% CI 234.53-247.47). CNVplex is a novel effective assay for diagnosing fetal chromosomal abnormalities associated with recurrent pregnancy loss. In the routine clinical work-up of recurrent pregnancy loss, diagnostic accuracy of CNVplex is comparable to that of conventional karyotyping but it requires less waiting time and has lower cost. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

A novel method to produce armored double-stranded DNA by encapsulation of MS2 viral capsids.

PubMed

Zhang, Lei; Sun, Yu; Chang, Le; Jia, Tingting; Wang, Guojing; Zhang, Rui; Zhang, Kuo; Li, Jinming

2015-09-01

With the rapid development of molecular diagnostic techniques, there is a growing need for quality controls and standards with favorable properties to monitor the entire detection process. In this study, we describe a novel method to produce armored hepatitis B virus (HBV) and human papillomavirus (HPV) DNA for use in nucleic acid tests, which was confirmed to be stable, homogeneous, noninfectious, nuclease resistant, and safe for shipping. We demonstrated that MS2 bacteriophage could successfully package double-stranded DNA of 1.3-, 3-, 3.5-, and 6.5-kb length into viral capsids with high reassembly efficiency. This is the first application of RNA bacteriophage MS2 as a platform to encapsulate double-stranded DNA, forming virus-like particles (VLPs) which were indistinguishable from native MS2 capsids in size and morphology. Moreover, by analyzing the interaction mechanism of pac site and the MS2 coat protein (CP), we found that in addition to the recognized initiation signal TR-RNA, TR-DNA can also trigger spontaneous reassembly of CP dimers, providing a more convenient and feasible method of assembly. In conclusion, this straightforward and reliable manufacturing approach makes armored DNA an ideal control and standard for use in clinical laboratory tests and diagnostics, possessing prospects for broad application, especially providing a new platform for the production of quality controls for DNA viruses.

Combined photoacoustic and ultrasonic diagnosis of early bone loss and density variations

NASA Astrophysics Data System (ADS)

Lashkari, Bahman; Mandelis, Andreas

2012-02-01

Over the past two decades, osteoporosis has been recognized among the most serious public health problems. Fortunately with the growing awareness of osteoporosis, new treatments have been developed for the prevention of fracture. At the same time, there is a rapid improvement in diagnostic methods. In this study biomedical photoacoustics (PA) is applied to the analysis of bone mineral concentration. The PA signal depends on optical as well as mechanical properties of the object and therefore has the potential to provide higher sensitivity to density variations compared with standard diagnostic methods, like ultrasound. A laser source with 800 nm wavelength and different ultrasonic transducers with resonance frequencies in the range 1 to 5 MHz were employed. The CW or frequency-domain (FD) PA radar method was utilized with linear frequency modulation chirps to provide temporal gating control over the transmitted signal and higher sensitivity in the detected signal. The laser intensity was set below the safety standards for skin exposure. The preliminary studies showed adequate optical absorption by cortical bone to generate measurable PA signals and the transmission of laser light through this layer. Experiments are focused on detection and evaluation of PA signals from in-vitro animal cortical bones with and without a trabecular sublayer. The trabecular layer is then diluted by chemical etching and differences in the PA signals are discussed.

Application of Multilabel Learning Using the Relevant Feature for Each Label in Chronic Gastritis Syndrome Diagnosis

PubMed Central

Liu, Guo-Ping; Yan, Jian-Jun; Wang, Yi-Qin; Fu, Jing-Jing; Xu, Zhao-Xia; Guo, Rui; Qian, Peng

2012-01-01

Background. In Traditional Chinese Medicine (TCM), most of the algorithms are used to solve problems of syndrome diagnosis that only focus on one syndrome, that is, single label learning. However, in clinical practice, patients may simultaneously have more than one syndrome, which has its own symptoms (signs). Methods. We employed a multilabel learning using the relevant feature for each label (REAL) algorithm to construct a syndrome diagnostic model for chronic gastritis (CG) in TCM. REAL combines feature selection methods to select the significant symptoms (signs) of CG. The method was tested on 919 patients using the standard scale. Results. The highest prediction accuracy was achieved when 20 features were selected. The features selected with the information gain were more consistent with the TCM theory. The lowest average accuracy was 54% using multi-label neural networks (BP-MLL), whereas the highest was 82% using REAL for constructing the diagnostic model. For coverage, hamming loss, and ranking loss, the values obtained using the REAL algorithm were the lowest at 0.160, 0.142, and 0.177, respectively. Conclusion. REAL extracts the relevant symptoms (signs) for each syndrome and improves its recognition accuracy. Moreover, the studies will provide a reference for constructing syndrome diagnostic models and guide clinical practice. PMID:22719781

A Multicenter comparative trial of a novel EUS-guided core biopsy needle (SharkCore™) with the 22-gauge needle in patients with solid pancreatic mass lesions

PubMed Central

Naveed, Mariam; Siddiqui, Ali A.; Kowalski, Thomas E.; Loren, David E.; Khalid, Ammara; Soomro, Ayesha; Mazhar, Syed M.; Yoo, Joseph; Hasan, Raza; Yalamanchili, Silpa; Tarangelo, Nicholas; Taylor, Linda J.; Adler, Douglas G.

2018-01-01

Background and Objectives: The ability to obtain adequate tissue of solid pancreatic lesions by EUS-guided remains a challenge. The aim of this study was to compare the performance characteristics and safety of EUS-FNA for evaluating solid pancreatic lesions using the standard 22-gauge needle versus a novel EUS biopsy needle. Methods: This was a multicenter retrospective study of EUS-guided sampling of solid pancreatic lesions between 2009 and 2015. Patients underwent EUS-guided sampling with a 22-gauge SharkCore (SC) needle or a standard 22-gauge FNA needle. Technical success, performance characteristics of EUS-FNA, the number of needle passes required to obtain a diagnosis, diagnostic accuracy, and complications were compared. Results: A total of 1088 patients (mean age = 66 years; 49% female) with pancreatic masses underwent EUS-guided sampling with a 22-gauge SC needle (n = 115) or a standard 22-gauge FNA needle (n = 973). Technical success was 100%. The frequency of obtaining an adequate cytology by EUS-FNA was similar when using the SC and the standard needle (94.1% vs. 92.7%, respectively). The sensitivity, specificity, and diagnostic accuracy of EUS-FNA for tissue diagnosis were not significantly different between two needles. Adequate sample collection leading to a definite diagnosis was achieved by the 1st, 2nd, and 3rd pass in 73%, 92%, and 98% of procedures using the SC needle and 20%, 37%, and 94% procedures using the standard needle (P < 0.001), respectively. The median number of passes to obtain a tissue diagnosis using the SC needle was significantly less as compared to the standard needle (1 and 3, respectively; P < 0.001). Conclusions: The EUS SC biopsy needle is safe and technically feasible for EUS-FNA of solid pancreatic mass lesions. Preliminary results suggest that the SC needle has a diagnostic yield similar to the standard EUS needle and significantly reduces the number of needle passes required to obtain a tissue diagnosis. PMID:29451167

[Prostate biopsy under magnetic resonance imaging guidance].

PubMed

Kuplevatskiy, V I; CherkashiN, M A; Roshchin, D A; Berezina, N A; Vorob'ev, N A

2016-01-01

Prostate cancer (PC) is one of the most important problems in modern oncology. According to statistical data, PC ranks second in the cancer morbidity structure in the Russian Federation and developed countries and its prevalence has been progressively increasing over the past decade. A need for early diagnosis and maximally accurate morphological verification of the diagnosis in difficult clinical cases (inconvenient tumor location for standard transrectal biopsy; gland scarring changes concurrent with prostatitis and hemorrhage; threshold values of prostate-specific antigen with unclear changes in its doubling per unit time; suspicion of biochemical recurrence or clinical tumor progression after special treatment) leads to revised diagnostic algorithms and clinically introduced new high-tech invasive diagnostic methods. This paper gives the first analysis of literature data on Russian practice using one of the new methods to verify prostate cancer (transrectal prostate cancer under magnetic resonance imaging (MRI) guidance). The have sought the 1995-2015 data in the MEDLINE and Pubmed.

Blood glucose measurement by glucometer in comparison with standard method in diagnosis of neonatal hypoglycemia.

PubMed

Nayeri, Fatemeh; Shariat, Mamak; Mousavi Behbahani, Hamid Modarres; Dehghan, Padideh; Ebrahim, Bita

2014-01-01

Hypoglycemia is considered as a serious risk factor in neonates. In the majority of cases, it occurs with no clinical symptoms. Accordingly, early diagnosis is extremely imperative, which can also lead to less morbidity and mortality. The aim of this study was to assess the importance of screening blood glucose using glucometer (known as a quick and cost-effective diagnostic test) in comparison with laboratory method. A total of 219 neonates at risk of hypoglycemia were included in this study. Blood glucose was measured by glucometer and laboratory. In addition glucose level of capillary blood was measured by glucometer at the same time. Sensitivity and specificity of capillary blood glucose measurement by glucometer were 83.5%, 97.5% respectively (ppv=80%), (npv=98%). Capillary blood glucose measured by glucometer has an acceptable sensitivity and specificity in measurement of neonatal blood glucose. Therefore measurement by glucometer is recommended as a proper diagnostic test.

[Achilles tendon rupture : Current diagnostic and therapeutic standards].

PubMed

Hertel, G; Götz, J; Grifka, J; Willers, J

2016-08-01

A superior life expectancy and an increased activity in the population result in an increase in degenerative diseases, such as Achilles tendon ruptures. The medical history and physical examinations are the methods of choice to diagnose Achilles tendon ruptures. Ultrasound and radiography represent reasonable extended diagnostic procedures. In order to decide on the medical indications for the therapy concept, the advantages and disadvantages of conservative and surgical treatment options have to be weighed up on an indivdual basis. There are explicit contraindications for both treatment options. For the surgical treatment concept open suture techniques, minimally invasive methods and reconstructive procedures are available. The postoperative management of the patient is as important as the choice of surgical technique. With the correct medical indications and supervision of the patient it is possible to achieve extremely satisfying results for the patient with both conservative and surgical treatment options.

OSA severity assessment based on sleep breathing analysis using ambient microphone.

PubMed

Dafna, E; Tarasiuk, A; Zigel, Y

2013-01-01

In this paper, an audio-based system for severity estimation of obstructive sleep apnea (OSA) is proposed. The system estimates the apnea-hypopnea index (AHI), which is the average number of apneic events per hour of sleep. This system is based on a Gaussian mixture regression algorithm that was trained and validated on full-night audio recordings. Feature selection process using a genetic algorithm was applied to select the best features extracted from time and spectra domains. A total of 155 subjects, referred to in-laboratory polysomnography (PSG) study, were recruited. Using the PSG's AHI score as a gold-standard, the performances of the proposed system were evaluated using a Pearson correlation, AHI error, and diagnostic agreement methods. Correlation of R=0.89, AHI error of 7.35 events/hr, and diagnostic agreement of 77.3% were achieved, showing encouraging performances and a reliable non-contact alternative method for OSA severity estimation.

Modeling companion diagnostics in economic evaluations of targeted oncology therapies: systematic review and methodological checklist.

PubMed

Doble, Brett; Tan, Marcus; Harris, Anthony; Lorgelly, Paula

2015-02-01

The successful use of a targeted therapy is intrinsically linked to the ability of a companion diagnostic to correctly identify patients most likely to benefit from treatment. The aim of this study was to review the characteristics of companion diagnostics that are of importance for inclusion in an economic evaluation. Approaches for including these characteristics in model-based economic evaluations are compared with the intent to describe best practice methods. Five databases and government agency websites were searched to identify model-based economic evaluations comparing a companion diagnostic and subsequent treatment strategy to another alternative treatment strategy with model parameters for the sensitivity and specificity of the companion diagnostic (primary synthesis). Economic evaluations that limited model parameters for the companion diagnostic to only its cost were also identified (secondary synthesis). Quality was assessed using the Quality of Health Economic Studies instrument. 30 studies were included in the review (primary synthesis n = 12; secondary synthesis n = 18). Incremental cost-effectiveness ratios may be lower when the only parameter for the companion diagnostic included in a model is the cost of testing. Incorporating the test's accuracy in addition to its cost may be a more appropriate methodological approach. Altering the prevalence of the genetic biomarker, specific population tested, type of test, test accuracy and timing/sequence of multiple tests can all impact overall model results. The impact of altering a test's threshold for positivity is unknown as it was not addressed in any of the included studies. Additional quality criteria as outlined in our methodological checklist should be considered due to the shortcomings of standard quality assessment tools in differentiating studies that incorporate important test-related characteristics and those that do not. There is a need to refine methods for incorporating the characteristics of companion diagnostics into model-based economic evaluations to ensure consistent and transparent reimbursement decisions are made.

Measuring diagnostic and predictive accuracy in disease management: an introduction to receiver operating characteristic (ROC) analysis.

PubMed

Linden, Ariel

2006-04-01

Diagnostic or predictive accuracy concerns are common in all phases of a disease management (DM) programme, and ultimately play an influential role in the assessment of programme effectiveness. Areas, such as the identification of diseased patients, predictive modelling of future health status and costs and risk stratification, are just a few of the domains in which assessment of accuracy is beneficial, if not critical. The most commonly used analytical model for this purpose is the standard 2 x 2 table method in which sensitivity and specificity are calculated. However, there are several limitations to this approach, including the reliance on a single defined criterion or cut-off for determining a true-positive result, use of non-standardized measurement instruments and sensitivity to outcome prevalence. This paper introduces the receiver operator characteristic (ROC) analysis as a more appropriate and useful technique for assessing diagnostic and predictive accuracy in DM. Its advantages include; testing accuracy across the entire range of scores and thereby not requiring a predetermined cut-off point, easily examined visual and statistical comparisons across tests or scores, and independence from outcome prevalence. Therefore the implementation of ROC as an evaluation tool should be strongly considered in the various phases of a DM programme.

A novel assay for the detection of anti-human platelet antigen antibodies (HPA-1a) based on peptide aptamer technology

PubMed Central

Thibaut, Julien; Mérieux, Yves; Rigal, Dominique; Gillet, Germain

2012-01-01

Background Neonatal alloimmune thrombocytopenia is mostly due to the presence of maternal antibodies against the fetal platelet antigen HPA-1a on the platelet integrin GPIIb-IIIa. Accurate detection of anti-HPA-1a antibodies in the mother is, therefore, critical. Current diagnostic assays rely on the availability of pools of human platelets that vary according to donors and blood centers. There is still no satisfactory standardization of these assays. Design and Methods Peptide aptamer was used to detect and identify HPA-1a-specific antibodies in human serum that do not require human platelets. A peptide aptamer library was screened using an anti-HPA-1a human monoclonal antibody as a bait to isolate an aptamer that mimics the human platelet antigen HPA-1a. Results This is the first report in platelet immunology of the use of a peptide aptamer for diagnostic purposes. This assay gives better results than the MAIPA currently in use, detecting around 90% of the expected alloantibodies. Conclusions This assay could help define a standard for the quantitation of anti-HPA antibodies. This report also demonstrates that peptide aptamers can potentially detect a variety of biomarkers in body fluids; this is of particular interest for diagnostic purposes. PMID:22133781

A malaria diagnostic tool based on computer vision screening and visualization of Plasmodium falciparum candidate areas in digitized blood smears.

PubMed

Linder, Nina; Turkki, Riku; Walliander, Margarita; Mårtensson, Andreas; Diwan, Vinod; Rahtu, Esa; Pietikäinen, Matti; Lundin, Mikael; Lundin, Johan

2014-01-01

Microscopy is the gold standard for diagnosis of malaria, however, manual evaluation of blood films is highly dependent on skilled personnel in a time-consuming, error-prone and repetitive process. In this study we propose a method using computer vision detection and visualization of only the diagnostically most relevant sample regions in digitized blood smears. Giemsa-stained thin blood films with P. falciparum ring-stage trophozoites (n = 27) and uninfected controls (n = 20) were digitally scanned with an oil immersion objective (0.1 µm/pixel) to capture approximately 50,000 erythrocytes per sample. Parasite candidate regions were identified based on color and object size, followed by extraction of image features (local binary patterns, local contrast and Scale-invariant feature transform descriptors) used as input to a support vector machine classifier. The classifier was trained on digital slides from ten patients and validated on six samples. The diagnostic accuracy was tested on 31 samples (19 infected and 12 controls). From each digitized area of a blood smear, a panel with the 128 most probable parasite candidate regions was generated. Two expert microscopists were asked to visually inspect the panel on a tablet computer and to judge whether the patient was infected with P. falciparum. The method achieved a diagnostic sensitivity and specificity of 95% and 100% as well as 90% and 100% for the two readers respectively using the diagnostic tool. Parasitemia was separately calculated by the automated system and the correlation coefficient between manual and automated parasitemia counts was 0.97. We developed a decision support system for detecting malaria parasites using a computer vision algorithm combined with visualization of sample areas with the highest probability of malaria infection. The system provides a novel method for blood smear screening with a significantly reduced need for visual examination and has a potential to increase the throughput in malaria diagnostics.

Accuracy of LightCycler® SeptiFast for the detection and identification of pathogens in the blood of patients with suspected sepsis: a systematic review protocol

PubMed Central

Wilson, Claire; Blackwood, Bronagh; McAuley, Danny F; Perkins, Gavin D; McMullan, Ronan; Gates, Simon; Warhurst, Geoffrey

2012-01-01

Background There is growing interest in the potential utility of molecular diagnostics in improving the detection of life-threatening infection (sepsis). LightCycler® SeptiFast is a multipathogen probe-based real-time PCR system targeting DNA sequences of bacteria and fungi present in blood samples within a few hours. We report here the protocol of the first systematic review of published clinical diagnostic accuracy studies of this technology when compared with blood culture in the setting of suspected sepsis. Methods/design Data sources: the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment Database (HTA), the NHS Economic Evaluation Database (NHSEED), The Cochrane Library, MEDLINE, EMBASE, ISI Web of Science, BIOSIS Previews, MEDION and the Aggressive Research Intelligence Facility Database (ARIF). Study selection: diagnostic accuracy studies that compare the real-time PCR technology with standard culture results performed on a patient's blood sample during the management of sepsis. Data extraction: three reviewers, working independently, will determine the level of evidence, methodological quality and a standard data set relating to demographics and diagnostic accuracy metrics for each study. Statistical analysis/data synthesis: heterogeneity of studies will be investigated using a coupled forest plot of sensitivity and specificity and a scatter plot in Receiver Operator Characteristic (ROC) space. Bivariate model method will be used to estimate summary sensitivity and specificity. The authors will investigate reporting biases using funnel plots based on effective sample size and regression tests of asymmetry. Subgroup analyses are planned for adults, children and infection setting (hospital vs community) if sufficient data are uncovered. Dissemination Recommendations will be made to the Department of Health (as part of an open-access HTA report) as to whether the real-time PCR technology has sufficient clinical diagnostic accuracy potential to move forward to efficacy testing during the provision of routine clinical care. Registration PROSPERO—NIHR Prospective Register of Systematic Reviews (CRD42011001289). PMID:22240646

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region

PubMed Central

Medeiros, Jansen Fernandes; Fontes, Gilberto; do Nascimento, Vilma Lopes; Rodrigues, Moreno; Cohen, Jacob; de Andrade, Edmar Vaz; Pessoa, Felipe Arley Costa; Martins, Marilaine

2018-01-01

BACKGROUND The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. OBJECTIVES This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. METHODS Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. FINDINGS The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI): 92.0 - 99.7] for PCR and 83.5% (95% CI: 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI: 93.7 - 100) for PCR and 98.3% (95% CI: 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. MAIN CONCLUSIONS PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears). PMID:29412356

Fluorescence-based methods for detecting caries lesions: systematic review, meta-analysis and sources of heterogeneity.

PubMed

Gimenez, Thais; Braga, Mariana Minatel; Raggio, Daniela Procida; Deery, Chris; Ricketts, David N; Mendes, Fausto Medeiros

2013-01-01

Fluorescence-based methods have been proposed to aid caries lesion detection. Summarizing and analysing findings of studies about fluorescence-based methods could clarify their real benefits. We aimed to perform a comprehensive systematic review and meta-analysis to evaluate the accuracy of fluorescence-based methods in detecting caries lesions. Two independent reviewers searched PubMed, Embase and Scopus through June 2012 to identify papers/articles published. Other sources were checked to identify non-published literature. STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND DIAGNOSTIC METHODS: The eligibility criteria were studies that: (1) have assessed the accuracy of fluorescence-based methods of detecting caries lesions on occlusal, approximal or smooth surfaces, in both primary or permanent human teeth, in the laboratory or clinical setting; (2) have used a reference standard; and (3) have reported sufficient data relating to the sample size and the accuracy of methods. A diagnostic 2×2 table was extracted from included studies to calculate the pooled sensitivity, specificity and overall accuracy parameters (Diagnostic Odds Ratio and Summary Receiver-Operating curve). The analyses were performed separately for each method and different characteristics of the studies. The quality of the studies and heterogeneity were also evaluated. Seventy five studies met the inclusion criteria from the 434 articles initially identified. The search of the grey or non-published literature did not identify any further studies. In general, the analysis demonstrated that the fluorescence-based method tend to have similar accuracy for all types of teeth, dental surfaces or settings. There was a trend of better performance of fluorescence methods in detecting more advanced caries lesions. We also observed moderate to high heterogeneity and evidenced publication bias. Fluorescence-based devices have similar overall performance; however, better accuracy in detecting more advanced caries lesions has been observed.

Diagnostic efficacy of microscopy, rapid diagnostic test and polymerase chain reaction for malaria using bayesian latent class analysis.

PubMed

Saha, Sreemanti; Narang, Rahul; Deshmukh, Pradeep; Pote, Kiran; Anvikar, Anup; Narang, Pratibha

2017-01-01

The diagnostic techniques for malaria are undergoing a change depending on the availability of newer diagnostics and annual parasite index of infection in a particular area. At the country level, guidelines are available for selection of diagnostic tests; however, at the local level, this decision is made based on malaria situation in the area. The tests are evaluated against the gold standard, and if that standard has limitations, it becomes difficult to compare other available tests. Bayesian latent class analysis computes its internal standard rather than using the conventional gold standard and helps comparison of various tests including the conventional gold standard. In a cross-sectional study conducted in a tertiary care hospital setting, we have evaluated smear microscopy, rapid diagnostic test (RDT), and polymerase chain reaction (PCR) for diagnosis of malaria using Bayesian latent class analysis. We found the magnitude of malaria to be 17.7% (95% confidence interval: 12.5%-23.9%) among the study subjects. In the present study, the sensitivity of microscopy was 63%, but it had very high specificity (99.4%). Sensitivity and specificity of RDT and PCR were high with RDT having a marginally higher sensitivity (94% vs. 90%) and specificity (99% vs. 95%). On comparison of likelihood ratios (LRs), RDT had the highest LR for positive test result (175) and the lowest LR for negative test result (0.058) among the three tests. In settings like ours conventional smear microscopy may be replaced with RDT and as we move toward elimination and facilities become available PCR may be roped into detect cases with lower parasitaemia.

Indiana Reading Diagnostic Assessment: Resource & Intervention Guide, Kindergarten. Additional Activities and Assessments

ERIC Educational Resources Information Center

Indiana Department of Education, 2006

2006-01-01

The materials included in this manual are organized according to the Indiana's Kindergarten Academic Standards for English/Language Arts. In each section teachers will find: (1) Indiana's Kindergarten Academic Standards for English/Language Arts Assessments: Black Line Masters of diagnostic/practice pages for skill areas, checklists, and rubrics;…

76 FR 70128 - California State Motor Vehicle Pollution Control Standards; Amendments to the California Heavy...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

... Standards; Amendments to the California Heavy-Duty Engine On-Board Diagnostic Regulation; Waiver Request... that it has adopted amendments to its regulations related to heavy-duty engine on-board diagnostic (HD... and gasoline powered heavy-duty engines (engines used in vehicles having a gross vehicle weight rating...

Artificial intelligence techniques applied to the development of a decision–support system for diagnosing celiac disease

PubMed Central

Tenório, Josceli Maria; Hummel, Anderson Diniz; Cohrs, Frederico Molina; Sdepanian, Vera Lucia; Pisa, Ivan Torres; de Fátima Marin, Heimar

2013-01-01

Background Celiac disease (CD) is a difficult-to-diagnose condition because of its multiple clinical presentations and symptoms shared with other diseases. Gold-standard diagnostic confirmation of suspected CD is achieved by biopsying the small intestine. Objective To develop a clinical decision–support system (CDSS) integrated with an automated classifier to recognize CD cases, by selecting from experimental models developed using intelligence artificial techniques. Methods A web-based system was designed for constructing a retrospective database that included 178 clinical cases for training. Tests were run on 270 automated classifiers available in Weka 3.6.1 using five artificial intelligence techniques, namely decision trees, Bayesian inference, k-nearest neighbor algorithm, support vector machines and artificial neural networks. The parameters evaluated were accuracy, sensitivity, specificity and area under the ROC curve (AUC). AUC was used as a criterion for selecting the CDSS algorithm. A testing database was constructed including 38 clinical CD cases for CDSS evaluation. The diagnoses suggested by CDSS were compared with those made by physicians during patient consultations. Results The most accurate method during the training phase was the averaged one-dependence estimator (AODE) algorithm (a Bayesian classifier), which showed accuracy 80.0%, sensitivity 0.78, specificity 0.80 and AUC 0.84. This classifier was integrated into the web-based decision–support system. The gold-standard validation of CDSS achieved accuracy of 84.2% and k = 0.68 (p < 0.0001) with good agreement. The same accuracy was achieved in the comparison between the physician’s diagnostic impression and the gold standard k = 0. 64 (p < 0.0001). There was moderate agreement between the physician’s diagnostic impression and CDSS k = 0.46 (p = 0.0008). Conclusions The study results suggest that CDSS could be used to help in diagnosing CD, since the algorithm tested achieved excellent accuracy in differentiating possible positive from negative CD diagnoses. This study may contribute towards developing of a computer-assisted environment to support CD diagnosis. PMID:21917512

Real Time Polymerase Chain Reaction (rt-PCR): A New Patent to Diagnostic Purposes for Paracoccidioidomycosis.

PubMed

Rocha-Silva, Fabiana; Gomes, Luciana I; Gracielle-Melo, Cidiane; Goes, Alfredo M; Caligiorne, Rachel B

2017-01-01

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by dimorphic fungi Paracoccidioides brasiliensis and Paracoccidioides lutzii. It is prevalent in Latin American, mainly in Brazil. Therefore, PCM has fundamental impact on the Brazilian global economy, especially in public health system, since it is affecting economical active population in different country regions. The present study aimed to standardize the Real Time-Polymerase Chain Reaction (rt-PCR) for an efficient and safe PCM diagnosis amplifying the recombinant protein PB27 gene, only expressed by specimens of Paracoccidioides genus. To standardize a methodology of rt-PCR using species-specific primers and probe designed for annealing in this specific region of the fungi´s genome, amplifying the recombinant protein PB27 gene, only expressed by specimens of Paracoccidioides genus. Followed by design in silico, experiments were performed in vitro to determine rt-PCR specificity, efficiency and genome detection limit. The primers and probe sequences were deposited in Brazilian Coordination of Technological Innovation and Transfer (CTIT), under patent reference number BR1020160078830. The present study demonstrated the rt-PCR applicability for support on diagnosis of paracoccidioidomycosis, presenting low cost, which makes it affordable for public health services in developing countries as Brazil. It is noteworthy that it is necessary to validate this methodology using clinical samples before to use as a safe method of diagnosis. A review of all patents related to this topic was performed and it was shown that, to date, there are no records of patent on kits for paracoccidioidomycosis´s diagnostic. Indeed, there is still a lot to go to reach this goal. The reaction developed was standardized and patented, opening perspectives to molecular diagnosis development for paracoccidioidomycosis, since rt-PCR can be applied to a broad spectrum of infectious diseases. It would need to be tested in biological samples in order to validate this method and then generate a diagnostic kit for Paracoccidioidomycosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The STARD Statement for Reporting Diagnostic Accuracy Studies: Application to the History and Physical Examination

PubMed Central

Rennie, Drummond; Bossuyt, Patrick M. M.

2008-01-01

Summary Objective The Standards for Reporting of Diagnostic Accuracy (STARD) statement provided guidelines for investigators conducting diagnostic accuracy studies. We reviewed each item in the statement for its applicability to clinical examination diagnostic accuracy research, viewing each discrete aspect of the history and physical examination as a diagnostic test. Setting Nonsystematic review of the STARD statement. Interventions Two former STARD Group participants and 1 editor of a journal series on clinical examination research reviewed each STARD item. Suggested interpretations and comments were shared to develop consensus. Measurements and Main Results The STARD Statement applies generally well to clinical examination diagnostic accuracy studies. Three items are the most important for clinical examination diagnostic accuracy studies, and investigators should pay particular attention to their requirements: describe carefully the patient recruitment process, describe participant sampling and address if patients were from a consecutive series, and describe whether the clinicians were masked to the reference standard tests and whether the interpretation of the reference standard test was masked to the clinical examination components or overall clinical impression. The consideration of these and the other STARD items in clinical examination diagnostic research studies would improve the quality of investigations and strengthen conclusions reached by practicing clinicians. Conclusions The STARD statement provides a very useful framework for diagnostic accuracy studies. The group correctly anticipated that there would be nuances applicable to studies of the clinical examination. We offer guidance that should enhance their usefulness to investigators embarking on original studies of a patient’s history and physical examination. PMID:18347878

Issues in the Assessment of Social Phobia: A Review

PubMed Central

Letamendi, Andrea M.; Chavira, Denise A.; Stein, Murray B.

2010-01-01

Since the emergence of social phobia in DSM nomenclature, the mental health community has witnessed an expansion in standardized methods for the screening, diagnosis, and measurement of the disorder. This article reviews formal assessment methods for social phobia, including diagnostic interview, clinician-administered instruments, and self report questionnaires. Frequently used tools for assessing constructs related to social phobia, such as disability and quality of life, are also briefly presented. This review evaluates each method by highlighting the assessment features recommended in social phobia literature, including method of administration, item content, coverage, length of scale, type of scores generated, and time frame. PMID:19728569

International recommendation for a comprehensive neuropathologic workup of epilepsy surgery brain tissue: A consensus Task Force report from the ILAE Commission on Diagnostic Methods.

PubMed

Blümcke, Ingmar; Aronica, Eleonora; Miyata, Hajime; Sarnat, Harvey B; Thom, Maria; Roessler, Karl; Rydenhag, Bertil; Jehi, Lara; Krsek, Pavel; Wiebe, Samuel; Spreafico, Roberto

2016-03-01

Epilepsy surgery is an effective treatment in many patients with drug-resistant focal epilepsies. An early decision for surgical therapy is facilitated by a magnetic resonance imaging (MRI)-visible brain lesion congruent with the electrophysiologically abnormal brain region. Recent advances in the pathologic diagnosis and classification of epileptogenic brain lesions are helpful for clinical correlation, outcome stratification, and patient management. However, application of international consensus classification systems to common epileptic pathologies (e.g., focal cortical dysplasia [FCD] and hippocampal sclerosis [HS]) necessitates standardized protocols for neuropathologic workup of epilepsy surgery specimens. To this end, the Task Force of Neuropathology from the International League Against Epilepsy (ILAE) Commission on Diagnostic Methods developed a consensus standard operational procedure for tissue inspection, distribution, and processing. The aims are to provide a systematic framework for histopathologic workup, meeting minimal standards and maximizing current and future opportunities for morphofunctional correlations and molecular studies for both clinical care and research. Whenever feasible, anatomically intact surgical specimens are desirable to enable systematic analysis in selective hippocampectomies, temporal lobe resections, and lesional or nonlesional neocortical samples. Correct orientation of sample and the sample's relation to neurophysiologically aberrant sites requires good communication between pathology and neurosurgical teams. Systematic tissue sampling of 5-mm slabs along a defined anatomic axis and application of a limited immunohistochemical panel will ensure a reliable differential diagnosis of main pathologies encountered in epilepsy surgery. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Identifying and Quantifying Heterogeneity in High Content Analysis: Application of Heterogeneity Indices to Drug Discovery

PubMed Central

Gough, Albert H.; Chen, Ning; Shun, Tong Ying; Lezon, Timothy R.; Boltz, Robert C.; Reese, Celeste E.; Wagner, Jacob; Vernetti, Lawrence A.; Grandis, Jennifer R.; Lee, Adrian V.; Stern, Andrew M.; Schurdak, Mark E.; Taylor, D. Lansing

2014-01-01

One of the greatest challenges in biomedical research, drug discovery and diagnostics is understanding how seemingly identical cells can respond differently to perturbagens including drugs for disease treatment. Although heterogeneity has become an accepted characteristic of a population of cells, in drug discovery it is not routinely evaluated or reported. The standard practice for cell-based, high content assays has been to assume a normal distribution and to report a well-to-well average value with a standard deviation. To address this important issue we sought to define a method that could be readily implemented to identify, quantify and characterize heterogeneity in cellular and small organism assays to guide decisions during drug discovery and experimental cell/tissue profiling. Our study revealed that heterogeneity can be effectively identified and quantified with three indices that indicate diversity, non-normality and percent outliers. The indices were evaluated using the induction and inhibition of STAT3 activation in five cell lines where the systems response including sample preparation and instrument performance were well characterized and controlled. These heterogeneity indices provide a standardized method that can easily be integrated into small and large scale screening or profiling projects to guide interpretation of the biology, as well as the development of therapeutics and diagnostics. Understanding the heterogeneity in the response to perturbagens will become a critical factor in designing strategies for the development of therapeutics including targeted polypharmacology. PMID:25036749

An Overview on Prenatal Screening for Chromosomal Aberrations.

PubMed

Hixson, Lucas; Goel, Srishti; Schuber, Paul; Faltas, Vanessa; Lee, Jessica; Narayakkadan, Anjali; Leung, Ho; Osborne, Jim

2015-10-01

This article is a review of current and emerging methods used for prenatal detection of chromosomal aneuploidies. Chromosomal anomalies in the developing fetus can occur in any pregnancy and lead to death prior to or shortly after birth or to costly lifelong disabilities. Early detection of fetal chromosomal aneuploidies, an atypical number of certain chromosomes, can help parents evaluate their pregnancy options. Current diagnostic methods include maternal serum sampling or nuchal translucency testing, which are minimally invasive diagnostics, but lack sensitivity and specificity. The gold standard, karyotyping, requires amniocentesis or chorionic villus sampling, which are highly invasive and can cause abortions. In addition, many of these methods have long turnaround times, which can cause anxiety in mothers. Next-generation sequencing of fetal DNA in maternal blood enables minimally invasive, sensitive, and reasonably rapid analysis of fetal chromosomal anomalies and can be of clinical utility to parents. This review covers traditional methods and next-generation sequencing techniques for diagnosing aneuploidies in terms of clinical utility, technological characteristics, and market potential. © 2015 Society for Laboratory Automation and Screening.

Comparative evaluation of matrix-assisted laser desorption ionisation-time of flight mass spectrometry and conventional phenotypic-based methods for identification of clinically important yeasts in a UK-based medical microbiology laboratory.

PubMed

Fatania, Nita; Fraser, Mark; Savage, Mike; Hart, Jason; Abdolrasouli, Alireza

2015-12-01

Performance of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) was compared in a side-by side-analysis with conventional phenotypic methods currently in use in our laboratory for identification of yeasts in a routine diagnostic setting. A diverse collection of 200 clinically important yeasts (19 species, five genera) were identified by both methods using standard protocols. Discordant or unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene. MALDI-TOF and conventional methods were in agreement for 182 isolates (91%) with correct identification to species level. Eighteen discordant results (9%) were due to rarely encountered species, hence the difficulty in their identification using traditional phenotypic methods. MALDI-TOF MS enabled rapid, reliable and accurate identification of clinically important yeasts in a routine diagnostic microbiology laboratory. Isolates with rare, unusual or low probability identifications should be confirmed using robust molecular methods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A new rapid diagnostic test for detection of anti-Schistosoma mansoni and anti-Schistosoma haematobium antibodies

PubMed Central

2013-01-01

Background Parasitological methods are widely used for the diagnosis of schistosomiasis. However, they are insensitive, particularly in areas of low endemicity, and labour-intensive. Immunoassays based on detection of anti-schistosome antibodies have the merit of high sensitivity and recently a rapid diagnostic test (RDT), incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for detection of anti-schistosome antibodies in blood has been developed. Here, we assessed the diagnostic performance of the SmCTF-RDT for S. mansoni and S. haematobium infections by comparing it with microscopy for egg detection. Methods A cross-sectional survey was carried out in Azaguié, south Côte d’Ivoire. 118 pre-school-aged children submitted two stool and two urine samples, which were subjected to the Kato-Katz and urine filtration methods for the detection of S. mansoni and S. haematobium eggs, respectively. Urine was also subjected to a commercially available cassette test for S. mansoni, which detects circulating cathodic antigen. A finger-prick blood sample was used for the SmCTF-RDT for detection of anti-S. mansoni and anti-S. haematobium antibodies. Results The prevalence of both anti-S. mansoni and anti-S. haematobium antibodies was more than three times higher than the prevalence of infection estimated by egg detection under a microscope. Using quadruplicate Kato-Katz as the reference standard for the diagnosis of S. mansoni infection, the sensitivity, negative predictive value (NPV), and positive predictive value (PPV) of the SmCTF-RDT was 75.0%, 84.2% and 22.5%, respectively. When two urine filtrations were considered as the reference standard for the diagnosis of S. haematobium infection, the sensitivity, NPV and PPV of SmCTF-RDT was 66.7%, 94.9% and 5.1%, respectively. The specificity of SmCTF-RDT, when using egg-detection as the reference standard, was estimated to be 34.4%. This low specificity may be a reflection of the relative insensitivity of the direct diagnostic approaches using microscopy. Conclusions The SmCTF-RDT is at least as sensitive as duplicate Kato-Katz and a single urine filtration for detection of S. mansoni and S. haematobium, respectively. Further investigations into the specificity of the test for anti-schistosome antibodies are necessary, but our results suggest that it may be a useful tool for mapping the prevalence of anti-schistosome antibodies in a given population pending intervention. PMID:23360734

Breast tumor malignancy modelling using evolutionary neural logic networks.

PubMed

Tsakonas, Athanasios; Dounias, Georgios; Panagi, Georgia; Panourgias, Evangelia

2006-01-01

The present work proposes a computer assisted methodology for the effective modelling of the diagnostic decision for breast tumor malignancy. The suggested approach is based on innovative hybrid computational intelligence algorithms properly applied in related cytological data contained in past medical records. The experimental data used in this study were gathered in the early 1990s in the University of Wisconsin, based in post diagnostic cytological observations performed by expert medical staff. Data were properly encoded in a computer database and accordingly, various alternative modelling techniques were applied on them, in an attempt to form diagnostic models. Previous methods included standard optimisation techniques, as well as artificial intelligence approaches, in a way that a variety of related publications exists in modern literature on the subject. In this report, a hybrid computational intelligence approach is suggested, which effectively combines modern mathematical logic principles, neural computation and genetic programming in an effective manner. The approach proves promising either in terms of diagnostic accuracy and generalization capabilities, or in terms of comprehensibility and practical importance for the related medical staff.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health.

PubMed

Miller, Eric; Sikes, Hadley D

Immunochromatographic rapid diagnostic tests (RDTs) have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs.

Addressing Barriers to the Development and Adoption of Rapid Diagnostic Tests in Global Health

PubMed Central

Miller, Eric; Sikes, Hadley D.

2015-01-01

Immunochromatographic rapid diagnostic tests (RDTs) have demonstrated significant potential for use as point-of-care diagnostic tests in resource-limited settings. Most notably, RDTs for malaria have reached an unparalleled level of technological maturity and market penetration, and are now considered an important complement to standard microscopic methods of malaria diagnosis. However, the technical development of RDTs for other infectious diseases, and their uptake within the global health community as a core diagnostic modality, has been hindered by a number of extant challenges. These range from technical and biological issues, such as the need for better affinity agents and biomarkers of disease, to social, infrastructural, regulatory and economic barriers, which have all served to slow their adoption and diminish their impact. In order for the immunochromatographic RDT format to be successfully adapted to other disease targets, to see widespread distribution, and to improve clinical outcomes for patients on a global scale, these challenges must be identified and addressed, and the global health community must be engaged in championing the broader use of RDTs. PMID:26594252

Diagnostic and Prognostic Value of Long-Axis Strain and Myocardial Contraction Fraction Using Standard Cardiovascular MR Imaging in Patients with Nonischemic Dilated Cardiomyopathies.

PubMed

Arenja, Nisha; Riffel, Johannes H; Fritz, Thomas; André, Florian; Aus dem Siepen, Fabian; Mueller-Hennessen, Matthias; Giannitsis, Evangelos; Katus, Hugo A; Friedrich, Matthias G; Buss, Sebastian J

2017-06-01

Purpose To assess the utility of established functional markers versus two additional functional markers derived from standard cardiovascular magnetic resonance (MR) images for their incremental diagnostic and prognostic information in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods Approval was obtained from the local ethics committee. MR images from 453 patients with NIDCM and 150 healthy control subjects were included between 2005 and 2013 and were analyzed retrospectively. Myocardial contraction fraction (MCF) was calculated by dividing left ventricular (LV) stroke volume by LV myocardial volume, and long-axis strain (LAS) was calculated from the distances between the epicardial border of the LV apex and the midpoint of a line connecting the origins of the mitral valve leaflets at end systole and end diastole. Receiver operating characteristic curve, Kaplan-Meier method, Cox regression, and classification and regression tree (CART) analyses were performed for diagnostic and prognostic performances. Results LAS (area under the receiver operating characteristic curve [AUC] = 0.93, P < .001) and MCF (AUC = 0.92, P < .001) can be used to discriminate patients with NIDCM from age- and sex-matched control subjects. A total of 97 patients reached the combined end point during a median follow-up of 4.8 years. In multivariate Cox regression analysis, only LV ejection fraction (EF) and LAS independently indicated the combined end point (hazard ratio = 2.8 and 1.9, respectively; P < .001 for both). In a risk stratification approach with classification and regression tree analysis, combined LV EF and LAS cutoff values were used to stratify patients into three risk groups (log-rank test, P < .001). Conclusion Cardiovascular MR-derived MCF and LAS serve as reliable diagnostic and prognostic markers in patients with NIDCM. LAS, as a marker for longitudinal contractile function, is an independent parameter for outcome and offers incremental information beyond LV EF and the presence of myocardial fibrosis. © RSNA, 2017 Online supplemental material is available for this article.

Reduced-cost Chlamydia trachomatis-specific multiplex real-time PCR diagnostic assay evaluated for ocular swabs and use by trachoma research programmes.

PubMed

Butcher, Robert; Houghton, Jo; Derrick, Tamsyn; Ramadhani, Athumani; Herrera, Beatriz; Last, Anna R; Massae, Patrick A; Burton, Matthew J; Holland, Martin J; Roberts, Chrissy H

2017-08-01

Trachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), is the leading infectious cause of preventable blindness. Many commercial platforms are available that provide highly sensitive and specific detection of Ct DNA. However, the majority of these commercial platforms are inaccessible for population-level surveys in resource-limited settings typical to trachoma control programmes. We developed two low-cost quantitative PCR (qPCR) tests for Ct using readily available reagents on standard real-time thermocyclers. Each multiplex qPCR test targets one genomic and one plasmid Ct target in addition to an endogenous positive control for Homo sapiens DNA. The quantitative performance of the qPCR assays in clinical samples was determined by comparison to a previously evaluated droplet digital PCR (ddPCR) test. The diagnostic performance of the qPCR assays were evaluated against a commercial assay (artus C. trachomatis Plus RG PCR, Qiagen) using molecular diagnostics quality control standards and clinical samples. We examined the yield of Ct DNA prepared from five different DNA extraction kits and a cold chain-free dry-sample preservation method using swabs spiked with fixed concentrations of human and Ct DNA. The qPCR assay was highly reproducible (Ct plasmid and genomic targets mean total coefficients of variance 41.5% and 48.3%, respectively). The assay detected 8/8 core specimens upon testing of a quality control panel and performed well in comparison to commercially marketed comparator test (sensitivity and specificity>90%). Optimal extraction and sample preservation methods for research applications were identified. We describe a pipeline from collection to diagnosis providing the most efficient sample preservation and extraction with significant per test cost savings over a commercial qPCR diagnostic assay. The assay and its evaluation should allow control programs wishing to conduct independent research within the context of trachoma control, access to an affordable test with defined performance characteristics. Copyright © 2017. Published by Elsevier B.V.

Comparison of saline infusion sonohysterography and hysteroscopy in diagnosis of premenopausal women with abnormal uterine bleeding.

PubMed

Soguktas, Suna; Cogendez, Ebru; Kayatas, Semra Eser; Asoglu, Mehmet Resit; Selcuk, Selcuk; Ertekin, Aktug

2012-03-01

The aim of this study was to compare the diagnostic effectiveness of transvaginal sonography (TVS), saline infusion sonohysterography (SIS), and diagnostic hysteroscopy (HS), with the pathologic specimen as a gold standard diagnostic method, in detecting endometrial pathology in premenopausal women with abnormal uterine bleeding. This prospective cohort study was conducted at Zeynep Kamil Education and Training Hospital, Istanbul, Turkey, and included 89 premenopausal women. All participants were examined first by TVS, further investigated with SIS and HS, and finally dilatation and curettage was performed when needed. The results obtained from these three methods were compared with the pathologic diagnoses. The positive and negative likelihood ratios (LR+ and LR-) of TVS, SIS and HS were calculated by comparison with the final pathological diagnosis. In addition, area under the curve (AUC) values were also calculated. Polypoid lesion was the most common abnormal pathology. LR+ and LR- of TVS, SIS, and HS were 3.13 and 0.15, 9.83 and 0.07, 13.7 and 0.02 respectively in detection of any abnormal pathology, and the AUCs of TVS, SIS, and HS were 0.804, 0.920, and 0.954 respectively. When the three procedures were compared with each other separately, HS had the best diagnostic accuracy, and the diagnostic accuracy of HS and SIS was superior to TVS (p(1)=0.000, p(2)=0.000). For the detection of polypoid lesions, HS was the most accurate diagnostic procedure (AUC=0.947), followed by SIS (AUC=0.894) and TVS (AUC=0.778). HS provides the most accurate diagnosis and allows treatment in the same session in premenopausal women with abnormal uterine bleeding. Published by Elsevier Ireland Ltd.

ULTRASONOGRAPHY, AN EFFECTIVE TOOL IN DIAGNOSING PLANTAR FASCIITIS: A SYSTEMATIC REVIEW OF DIAGNOSTIC TRIALS

PubMed Central

Wyland, Matthew; Applequist, Lee; Bolowsky, Erin; Klingensmith, Heather; Virag, Isaac

2016-01-01

Background Plantar fasciitis (PF) is the most common cause of heel pain that affects 10% of the general population, whether living an athletic or sedentary lifestyle. The most frequent mechanism of injury is an inflammatory response that is caused by repetitive micro trauma. Many techniques are available to diagnose PF, including the use of ultrasonography (US). Purpose The purpose of this study is to systematically review and appraise previously published articles published between the years 2000 and 2015 that evaluated the effectiveness of using US in the process of diagnosing PF, as compared to alternative diagnostic methods. Methods A total of eight databases were searched to systematically review scholarly (peer reviewed) diagnostic and intervention articles pertaining to the ability of US to diagnose PF. Results Using specific key words the preliminary search yielded 264 articles, 10 of which were deemed relevant for inclusion in the study. Two raters independently scored each article using the 15 point modified QUADAS scale. Discussion Six studies compared the diagnostic efficacy of US to another diagnostic technique to diagnose PF, and four studies focused on comparing baseline assessment of plantar fascia before subsequent intervention. The most notable US outcomes measured were plantar fascia thickness, enthesopathy, and hypoechogenicity. Conclusion US was found to be accurate and reliable compared to alternative reference standards like MRI in the diagnosis of PF. The general advantages of US (e.g. cost efficient, ease of administration, non-invasive, limited contraindications) make it a superior diagnostic modality in the diagnosis of PF. US should be considered in rehabilitation clinics to effectively diagnose PF and to accurately monitor improvement in the disease process following rehabilitation interventions. Level of Evidence 1A PMID:27757279

Diagnostic and Treatment Reproducibility of Cervical Intraepithelial Neoplasia / Squamous Intraepithelial Lesion and Factors Affecting the Diagnosis.

PubMed

Sağlam, Arzu; Usubütün, Alp; Dolgun, Anıl; Mutter, George L; Salman, M Coşkun; Kurtulan, Olcay; Akyol, Aytekin; Özkan, Eylem Akar; Baykara, Sema; Bülbül, Dilek; Calay, Zerrin; Eren, Funda; Gümürdülü, Derya; Haberal, Nihan; Ilvan, Şennur; Karaveli, Şeyda; Koyuncuoğlu, Meral; Müezzinoğlu, Bahar; Müftüoğlu, Kamil Hakan; Özen, Özlem; Özdemir, Necmettin; Peştereli, Elif; Ulukuş, Çağnur; Zekioğlu, Osman

2017-01-01

Inter-observer differences in the diagnosis of HPV related cervical lesions are problematic and response of gynecologists to these diagnostic entities is non-standardized. This study evaluated the diagnostic reproducibility of "cervical intraepithelial neoplasia" (CIN) and "squamous intraepithelial lesion" (SIL) diagnoses. 19 pathologists evaluated 66 cases once using H&E slides and once with immunohistochemical studies (p16, Ki-67 and Pro-ExC). Management response to diagnoses was evaluated amongst 12 gynecologists. Pathologists and gynecologists were also given a questionnaire about how additional information like smear results and age modify diagnosis and management. We show moderate interobserver diagnostic reproducibility amongst pathologists. The overall kappa value was 0.50 and 0.59 using the CIN and SIL classifications respectively. Impact of immunohistochemical evaluation on interpretation of cases differed and there was lack of statistically significant improvement of interobserver diagnostic reproducibility with the addition of immunohistochemistry. We saw that choice of treatment methods amongst gynecologists varied and overall concordance was only fair to moderate. The CIN2 diagnostic category was seen to have the lowest percentage agreement amongst both pathologists and gynecologists. We showed that pathologists had diagnostic "styles" and gynecologists had management "styles". In summary each pathologist had different diagnostic tendencies which were affected not only by histopathology and marker studies, but also by the patient management tendencies of the gynecologist that the pathologist worked with. The two-tiered modified Bethesda system improved diagnostic agreement. We concluded that immunohistochemistry should be used only to resolve problems in select cases and not for every case.

Diagnostic Hysteroscopy - A Retrospective Study of 1545 Cases

PubMed Central

STEFANESCU, Andreea; MARINESCU, Bogdan

2012-01-01

ABSTRACT Introduction: The development of hysteroscopy has provided a minimally invasive approach to common gynecologic problems, such as abnormal uterine bleeding. Diagnostic hysteroscopy is considered now "the gold standard" by the Association of Professors of Gynecology and Obstetrics (2002) in investigation of abnormal uterine bleeding (AUB) in order to rule out organic endouterine causes of AUB. Although the World Health Organization (WHO) recommends hysterosapingography (HSG) alone for management of infertile women many specialists use hysteroscopy as a first-line routine exam for infertility patients regardless of guidelines. Material and method: This paper is a retrospective study of 1545 diagnostic hysteroscopies performed in the "Prof. Dr. Panait Sirbu" Obstetrics and Gynecology Hospital between January 1, 2008 and June 30, 2011. The following parameters were studied: diagnostic hysteroscopy indications, type of anesthesia used, correlation between pre-and postoperative diagnoses. Outcomes: Of 1545 diagnostic hysteroscopies, 78% of cases were performed without anesthesia; of the total of 299 cases of primary infertility diagnostic hysteroscopy showed in 34% of cases tubal obstruction and endouterine pathology; of the total 396 cases of secondary infertility under investigation, diagnostic hysteroscopy showed in 40% of cases tubal obstruction and endouterine pathology; the highest accuracy of HSG was noted for uterine malformation and minimal accuracy was observed for intrauterine adhesions. Conclusions: Our experience supports the opinion that diagnostic hysteroscopy should be a first-line routine exam in infertility. Because of the high rate of false positive results for HSG in our study and considering the other studies in specialty literature, we always perform a diagnostic hysteroscopy before Assisted Human Reproduction procedures regardless of the HSG aspect. PMID:23483793

The diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients: A systematic review and diagnostic meta-analysis.

PubMed

Yoon, Hee Mang; Suh, Chong Hyun; Cho, Young Ah; Kim, Jeong Rye; Lee, Jin Seong; Jung, Ah Young; Kim, Jung Heon; Lee, Jeong-Yong; Kim, So Yeon

2018-06-01

To evaluate the diagnostic performance of reduced-dose CT for suspected appendicitis. A systematic search of the MEDLINE and EMBASE databases was carried out through to 10 January 2017. Studies evaluating the diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients were selected. Pooled summary estimates of sensitivity and specificity were calculated using hierarchical logistic regression modelling. Meta-regression was performed. Fourteen original articles with a total of 3,262 patients were included. For all studies using reduced-dose CT, the summary sensitivity was 96 % (95 % CI 93-98) with a summary specificity of 94 % (95 % CI 92-95). For the 11 studies providing a head-to-head comparison between reduced-dose CT and standard-dose CT, reduced-dose CT demonstrated a comparable summary sensitivity of 96 % (95 % CI 91-98) and specificity of 94 % (95 % CI 93-96) without any significant differences (p=.41). In meta-regression, there were no significant factors affecting the heterogeneity. The median effective radiation dose of the reduced-dose CT was 1.8 mSv (1.46-4.16 mSv), which was a 78 % reduction in effective radiation dose compared to the standard-dose CT. Reduced-dose CT shows excellent diagnostic performance for suspected appendicitis. • Reduced-dose CT shows excellent diagnostic performance for evaluating suspected appendicitis. • Reduced-dose CT has a comparable diagnostic performance to standard-dose CT. • Median effective radiation dose of reduced-dose CT was 1.8 mSv (1.46-4.16). • Reduced-dose CT achieved a 78 % dose reduction compared to standard-dose CT.

Sensitivity of diagnostic methods for Mansonella ozzardi microfilariae detection in the Brazilian Amazon Region.

PubMed

Medeiros, Jansen Fernandes; Fontes, Gilberto; Nascimento, Vilma Lopes do; Rodrigues, Moreno; Cohen, Jacob; Andrade, Edmar Vaz de; Pessoa, Felipe Arley Costa; Martins, Marilaine

2018-03-01

The human filarial worm Mansonella ozzardi is highly endemic in the large tributaries of the Amazon River. This infection is still highly neglected and can be falsely negative when microfilariae levels are low. This study investigated the frequency of individuals with M. ozzardi in riverine communities in Coari municipality, Brazilian Amazon. Different diagnostic methods including polymerase chain reaction (PCR), blood polycarbonate membrane filtration (PCMF), Knott's method (Knott), digital thick blood smears (DTBS) and venous thick blood smears (VTBS) were used to compare sensitivity and specificity among the methods. Data were analysed using PCMF and Bayesian latent class models (BLCM) as the gold standard. We used BLCM to calculate the prevalence of mansonelliasis based on the results of five diagnostic methods. The prevalence of mansonelliasis was 35.4% by PCMF and 30.1% by BLCM. PCR and Knott methods both possessed high sensitivity. Sensitivity relative to PCMF was 98.5% [95% confidence interval (CI): 92.0 - 99.7] for PCR and 83.5% (95% CI: 72.9 - 90.5) for Knott. Sensitivity derived by BLCM was 100% (95% CI 93.7 - 100) for PCMF, 100% (95% CI: 93.7 - 100) for PCR and 98.3% (95% CI: 90.6 - 99.9) for Knott. The odds ratio of being diagnosed as microfilaremic increased with age but did not differ between genders. Microfilariae loads were higher in subjects aged 30 - 45 and 45 - 60 years. PCMF and PCR were the best methods to assess the prevalence of mansonelliasis in our samples. As such, using these methods could lead to higher prevalence of mansonelliasis in this region than the most commonly used method (i.e., thick blood smears).

Laboratory diagnostics of chronic kidney disease in Croatia: state of the art

PubMed Central

Honović, Lorena; Matica, Jasminka; Knežević, Branka; Vojak, Sanela Šimić

2015-01-01

Introduction Early identification and management of chronic kidney disease (CKD) is highly cost-effective and can reduce the risk of kidney failure progression and cardiovascular disease. In 2014, the Joint Croatian Working Group (JCWG) for laboratory diagnostic of CKD on the behalf of Croatian society of medical biochemistry and laboratory medicine (CSMBLM) and Croatian chamber of medical biochemists (CCMB) conducted a survey across Croatian medical-biochemistry laboratories to assess the current practice in this area of laboratory medicine. The aim of this study was to present the data collected through the survey and to give insight about laboratory diagnostics of chronic kidney disease in Croatia. Materials and methods An invitation to participate in the survey was sent to all Croatian medical-biochemistry laboratories (N = 196). The questionnaire was designed in a form of questions and statements, with possible multiple answers, comprising 24 questions. Results The response rate was 80/196 (40.8%). 39 answers were from primary medical-biochemistry laboratories. 31/78 (0.40) laboratories measure creatinine with non-standardized method (uncompensated Jaffe method). 58/78 (0.74) of laboratories that measure creatinine do not report eGFR values. Similar number of laboratories (58/80, 0.73) do not measure urine albumin or protein. Conclusions There is a large heterogeneity among Croatian laboratories regarding measuring methods, reporting units and reference intervals (cut-off values), both for creatinine and urine albumin or protein. The two key prerequisites for CKD screening, automatic reporting of eGFR and albuminuria or proteinuria assessment, are not implemented nationwide. There is a need for harmonization in laboratory diagnostics of CKD in Croatia. PMID:25672470

Rapid and sensitive detection of Yersinia pestis using amplification of plague diagnostic bacteriophages monitored by real-time PCR.

PubMed

Sergueev, Kirill V; He, Yunxiu; Borschel, Richard H; Nikolich, Mikeljon P; Filippov, Andrey A

2010-06-28

Yersinia pestis, the agent of plague, has caused many millions of human deaths and still poses a serious threat to global public health. Timely and reliable detection of such a dangerous pathogen is of critical importance. Lysis by specific bacteriophages remains an essential method of Y. pestis detection and plague diagnostics. The objective of this work was to develop an alternative to conventional phage lysis tests--a rapid and highly sensitive method of indirect detection of live Y. pestis cells based on quantitative real-time PCR (qPCR) monitoring of amplification of reporter Y. pestis-specific bacteriophages. Plague diagnostic phages phiA1122 and L-413C were shown to be highly effective diagnostic tools for the detection and identification of Y. pestis by using qPCR with primers specific for phage DNA. The template DNA extraction step that usually precedes qPCR was omitted. phiA1122-specific qPCR enabled the detection of an initial bacterial concentration of 10(3) CFU/ml (equivalent to as few as one Y. pestis cell per 1-microl sample) in four hours. L-413C-mediated detection of Y. pestis was less sensitive (up to 100 bacteria per sample) but more specific, and thus we propose parallel qPCR for the two phages as a rapid and reliable method of Y. pestis identification. Importantly, phiA1122 propagated in simulated clinical blood specimens containing EDTA and its titer rise was detected by both a standard plating test and qPCR. Thus, we developed a novel assay for detection and identification of Y. pestis using amplification of specific phages monitored by qPCR. The method is simple, rapid, highly sensitive, and specific and allows the detection of only live bacteria.

Standardization in laboratory medicine: Adoption of common reference intervals to the Croatian population.

PubMed

Flegar-Meštrić, Zlata; Perkov, Sonja; Radeljak, Andrea

2016-03-26

Considering the fact that the results of laboratory tests provide useful information about the state of health of patients, determination of reference value is considered an intrinsic part in the development of laboratory medicine. There are still huge differences in the analytical methods used as well as in the associated reference intervals which could consequently significantly affect the proper assessment of patient health. In a constant effort to increase the quality of patients' care, there are numerous international initiatives for standardization and/or harmonization of laboratory diagnostics in order to achieve maximum comparability of laboratory test results and improve patient safety. Through the standardization and harmonization processes of analytical methods the ability to create unique reference intervals is achieved. Such reference intervals could be applied globally in all laboratories using methods traceable to the same reference measuring system and analysing the biological samples from the populations with similar socio-demographic and ethnic characteristics. In this review we outlined the results of the harmonization processes in Croatia in the field of population based reference intervals for clinically relevant blood and serum constituents which are in accordance with ongoing activity for worldwide standardization and harmonization based on traceability in laboratory medicine.

Standardization in laboratory medicine: Adoption of common reference intervals to the Croatian population

PubMed Central

Flegar-Meštrić, Zlata; Perkov, Sonja; Radeljak, Andrea

2016-01-01

Considering the fact that the results of laboratory tests provide useful information about the state of health of patients, determination of reference value is considered an intrinsic part in the development of laboratory medicine. There are still huge differences in the analytical methods used as well as in the associated reference intervals which could consequently significantly affect the proper assessment of patient health. In a constant effort to increase the quality of patients’ care, there are numerous international initiatives for standardization and/or harmonization of laboratory diagnostics in order to achieve maximum comparability of laboratory test results and improve patient safety. Through the standardization and harmonization processes of analytical methods the ability to create unique reference intervals is achieved. Such reference intervals could be applied globally in all laboratories using methods traceable to the same reference measuring system and analysing the biological samples from the populations with similar socio-demographic and ethnic characteristics. In this review we outlined the results of the harmonization processes in Croatia in the field of population based reference intervals for clinically relevant blood and serum constituents which are in accordance with ongoing activity for worldwide standardization and harmonization based on traceability in laboratory medicine. PMID:27019800

Preliminary report on the International Conference for the Development of Standards for the Treatment of Anorectal Malformations.

PubMed

Holschneider, Alexander; Hutson, John; Peña, Albert; Beket, Elhamy; Chatterjee, Subir; Coran, Arnold; Davies, Michael; Georgeson, Keith; Grosfeld, Jay; Gupta, Devendra; Iwai, Naomi; Kluth, Dieter; Martucciello, Giuseppe; Moore, Samuel; Rintala, Risto; Smith, E Durham; Sripathi, D V; Stephens, Douglas; Sen, Sudipta; Ure, Benno; Grasshoff, Sabine; Boemers, Thomas; Murphy, Feilin; Söylet, Yunus; Dübbers, Martin; Kunst, Marc

2005-10-01

Anorectal malformations (ARM) are common congenital anomalies seen throughout the world. Comparison of outcome data has been hindered because of confusion related to classification and assessment systems. The goals of the Krinkenbeck Conference on ARM was to develop standards for an International Classification of ARM based on a modification of fistula type and adding rare and regional variants, and design a system for comparable follow up studies. Lesions were classified into major clinical groups based on the fistula location (perineal, recto-urethral, recto-vesical, vestibular), cloacal lesions, those with no fistula and anal stenosis. Rare and regional variants included pouch colon, rectal atresia or stenosis, rectovaginal fistula, H-fistula and others. Groups would be analyzed according to the type of procedure performed stratified for confounding associated conditions such as sacral anomalies and tethered cord. A standard method for postoperative assessment of continence was determined. A new International diagnostic classification system, operative groupings and a method of postoperative assessment of continence was developed by consensus of a large contingent of participants experienced in the management of patients with ARM. These methods should allow for a common standardization of diagnosis and comparing postoperative results.

42 CFR 419.2 - Basis of payment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... prospective payment system establishes a national payment rate, standardized for geographic wage differences...) Capital-related costs; (9) Implantable items used in connection with diagnostic X-ray tests, diagnostic laboratory tests, and other diagnostic tests; (10) Durable medical equipment that is implantable; (11...

Effect of Recording Duration on the Diagnostic Performance of Multifocal Visual-evoked Potentials in High-risk Ocular Hypertension and Early Glaucoma

PubMed Central

Fortune, Brad; Zhang, Xian; Hood, Donald C.; Demirel, Shaban; Patterson, Emily; Jamil, Annisa; Mansberger, Steven L.; Cioffi, George A.; Johnson, Chris A.

2010-01-01

Purpose To evaluate the effect on diagnostic performance of reducing multifocal visual-evoked potential (mfVEP) recording duration from 16 to 8 minutes per eye. Methods Both eyes of 185 individuals with high-risk ocular hypertension or early glaucoma were studied. Two 8-minute mfVEP recordings were obtained for each eye in an ABBA order using VERIS. The first recording for each eye was compared against single run (1-Run) mfVEP normative data; the average of both recordings for each eye was compared against 2-Run normative data. Visual fields (VFs) were obtained by standard automated perimetry (SAP) within 22.3±27.0 days of the mfVEP. Stereo disc photographs and Heidelberg Retina Tomograph images were obtained together, within 24.8±50.4 days of the mfVEP and 33.1±62.9 days of SAP. Masked experts graded disc photographs as either glaucomatous optic neuropathy or normal. The overall Moorfields Regression Analysis result from the Heidelberg Retina Tomograph was used as a separate diagnostic classification. Thus, 4 diagnostic standards were applied in total, 2 based on optic disc structure alone and 2 others based on disc structure and SAP. Results Agreement between the 1-Run and 2-Run mfVEP was 90%. Diagnostic performance of the 1-Run mfVEP was similar to that of the 2-Run mfVEP for all 4 diagnostic standards. Sensitivity was slightly higher for the 2-Run mfVEP, whereas specificity was slightly higher for the 1-Run mfVEP. Conclusions If higher sensitivity is sought, the 2-Run mfVEP will provide better discrimination between groups of eyes with relatively high signal-to-noise ratio (eg, early glaucoma or high-risk suspects). But if higher specificity is a more important goal, the 1-Run mfVEP provides adequate sensitivity and requires only half the test time. Considered alongside prior studies, the present results suggest that the 1-Run mfVEP is an efficient way to confirm (or refute) the extent of VF loss in patients with moderate or advanced glaucoma, particularly in those with unreliable VFs, including malingering or other “functional” forms of VF loss. PMID:18414101

The diagnostic performance of CT-derived fractional flow reserve for evaluation of myocardial ischaemia confirmed by invasive fractional flow reserve: a meta-analysis.

PubMed

Li, S; Tang, X; Peng, L; Luo, Y; Dong, R; Liu, J

2015-05-01

To review the literature on the diagnostic accuracy of CT-derived fractional flow reserve (FFRCT) for the evaluation of myocardial ischaemia in patients with suspected or known coronary artery disease, with invasive fractional flow reserve (FFR) as the reference standard. A PubMed, EMBASE, and Cochrane cross-search was performed. The pooled diagnostic accuracy of FFRCT, with FFR as the reference standard, was primarily analysed, and then compared with that of CT angiography (CTA). The thresholds to diagnose ischaemia were FFR ≤0.80 or CTA ≥50% stenosis. Data extraction, synthesis, and statistical analysis were performed by standard meta-analysis methods. Three multicentre studies (NXT Trial, DISCOVER-FLOW study and DeFACTO study) were included, examining 609 patients and 1050 vessels. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) for FFRCT were 89% (85-93%), 71% (65-75%), 70% (65-75%), 90% (85-93%), 3.31 (1.79-6.14), 0.16 (0.11-0.23), and 21.21 (9.15-49.15) at the patient-level, and 83% (78-63%), 78% (75-81%), 61% (56-65%), 92% (89-90%), 4.02 (1.84-8.80), 0.22 (0.13-0.35), and 19.15 (5.73-63.93) at the vessel-level. At per-patient analysis, FFRCT has similar sensitivity but improved specificity, PPV, NPV, LR+, LR-, and DOR versus those of CTA. At per-vessel analysis, FFRCT had a slightly lower sensitivity, similar NPV, but improved specificity, PPV, LR+, LR-, and DOR compared with those of CTA. The area under the summary receiver operating characteristic curves for FFRCT was 0.8909 at patient-level and 0.8865 at vessel-level, versus 0.7402 for CTA at patient-level. FFRCT, which was associated with improved diagnostic accuracy versus CTA, is a viable alternative to FFR for detecting coronary ischaemic lesions. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Electrodiagnostic applications of somatosensory evoked high-frequency EEG oscillations: Technical considerations.

PubMed

Simpson, A J; Cunningham, M O; Baker, M R

2018-03-01

High frequency oscillations (HFOs) embedded within the somatosensory evoked potential (SEP) are not routinely recorded/measured as part of standard clinical SEPs. However, HFOs could provide important additional diagnostic/prognostic information in various patient groups in whom SEPs are tested routinely. One area is the management of patients with hypoxic ischaemic encephalopathy (HIE) in the intensive care unit (ICU). However, the sensitivity of standard clinical SEP recording techniques for detecting HFOs is unknown. SEPs were recorded using routine clinical methods in 17 healthy subjects (median nerve stimulation; 0.5 ms pulse width; 5 Hz; maximum 4000 stimuli) in an unshielded laboratory. Bipolar EEG recordings were acquired (gain 50 k; bandpass 3Hz-2 kHz; sampling rate 5 kHz; non-inverting electrode 2 cm anterior to C3/C4; inverting electrode 2 cm posterior to C3/C4). Data analysis was performed in MATLAB. SEP-HFOs were detected in 65% of controls using standard clinical recording techniques. In 3 controls without significant HFOs, experiments were repeated using a linear electrode array with higher spatial sampling frequency. SEP-HFOs were observed in all 3 subjects. Currently standard clinical methods of recording SEPs are not sufficiently sensitive to permit the inclusion of SEP-HFOs in routine clinical diagnostic/prognostic assessments. Whilst an increase in the number/density of EEG electrodes should improve the sensitivity for detecting SEP-HFOs, this requires confirmation. By improving and standardising clinical SEP recording protocols to permit the acquisition/analysis of SEP-HFOs, it should be possible to gain important insights into the pathophysiology of neurological disorders and refine the management of conditions such as HIE. Copyright © 2018. Published by Elsevier Inc.

Contrast-enhanced spectral mammography in patients with MRI contraindications.

PubMed

Richter, Vivien; Hatterman, Valerie; Preibsch, Heike; Bahrs, Sonja D; Hahn, Markus; Nikolaou, Konstantin; Wiesinger, Benjamin

2017-01-01

Background Contrast-enhanced spectral mammography (CESM) is a novel breast imaging technique providing comparable diagnostic accuracy to breast magnetic resonance imaging (MRI). Purpose To show that CESM in patients with MRI contraindications is feasible, accurate, and useful as a problem-solving tool, and to highlight its limitations. Material and Methods A total of 118 patients with MRI contraindications were examined by CESM. Histology was obtained in 94 lesions and used as gold standard for diagnostic accuracy calculations. Imaging data were reviewed retrospectively for feasibility, accuracy, and technical problems. The diagnostic yield of CESM as a problem-solving tool and for therapy response evaluation was reviewed separately. Results CESM was more accurate than mammography (MG) for lesion categorization (r = 0.731, P < 0.0001 vs. r = 0.279, P = 0.006) and for lesion size estimation (r = 0.738 vs. r = 0.689, P < 0.0001). Negative predictive value of CESM was significantly higher than of MG (85.71% vs. 30.77%, P < 0.0001). When used for problem-solving, CESM changed patient management in 2/8 (25%) cases. Superposition artifacts and timing problems affected diagnostic utility in 3/118 (2.5%) patients. Conclusion CESM is a feasible and accurate alternative for patients with MRI contraindications, but it is necessary to be aware of the method's technical limitations.

[Pathogenesis, diagnosis and therapy of Legionella infections].

PubMed

Lück, P C; Steinert, M

2006-05-01

Legionella species are ubiquitous in aquatic environments. About 50 years ago they entered the engineered (technical) environment, i.e. warm water systems with zones of stagnation. Since that time they represent a hygienic problem. After transmission to humans via aerosols legionellae might cause Legionella pneumonia (legionnaires' disease) or influenza-like respiratory infections (Pontiac fever). Epidemiological data suggest that Legionella strains might differ substantially in their virulence properties. Although the molecular basis is not understood L. pneumophila serogroup 1 especially MAb 3/1-positive strains cause the majority of infections. The main virulence feature is the ability to multiply intracellularly. After uptake into macrophages legionellae multiply in a specialized vacuole and finally lyse their host cells. Several bacterial factors like surface components, secretion systems and iron uptake systems are involved in this process. Since the clinical picture of Legionella pneumonia does not allow differentiation from pneumoniae caused by other pathogens, microbiological diagnostic methods are needed to establish the diagnosis. Cultivation of legionellae from clinical specimens, detection of antigens and DNA in patients' samples and detection of antibodies in serum samples are suitable methods. However, none of the diagnostic tests presently available offers the desired quality with respect to sensitivity and specificity. Therefore, the standard technique is to use several diagnostic tests in parallel. Advantages and disadvantages of the diagnostic procedures are discussed. Therapeutic options for Legionella infections are newer macrolides like azithromycin and chinolones (ciprofloxacin, levofloxacin and moxifloxacin).

[Influence of occupational factors on the bone and joint functional state in the upper extremities and cervical spine in female workers of clothing manufacture].

PubMed

Druzhinin, V N; Shardakova, É F; Cherniĭ, A N

2014-01-01

The studies using multiple X-ray methods covered influence of complex containing working process and occupational environment factors on locomotory apparatus of upper limbs and cervical spine in female seamers engaged into various productions. Comparative analysis involved results of regular (standard X-ray) and special X-ray methods (stereoroentgenography, high definition roentgenography, roentgen densitometry, roentgenogrammetry) in 370 examinees with early and moderate clinical symptoms of occupationally mediated diseases of the stated areas. X-ray studies of locomotory apparatus of upper limbs and cervical spine in clothing manufacture workers, with special diagnostic methods, enabled to determine incidence and severity of functional and structural changes more reliably than via standard examination. The changes revealed were assigned mostly in "early" and "moderate" categories and matched with occupational peculiarities of the workers examined.

The Autism Diagnostic Observation Schedule, Toddler Module: Standardized Severity Scores

ERIC Educational Resources Information Center

Esler, Amy N.; Bal, Vanessa Hus; Guthrie, Whitney; Wetherby, Amy; Weismer, Susan Ellis; Lord, Catherine

2015-01-01

Standardized calibrated severity scores (CSS) have been created for Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2) Modules 1-4 as a metric of the relative severity of autism-specific behaviors. Total and domain CSS were created for the Toddler Module to facilitate comparison to other modules. Analyses included 388 children with ASD…

From autoantibody research to standardized diagnostic assays in the management of human diseases - report of the 12th Dresden Symposium on Autoantibodies.

PubMed

Conrad, K; Andrade, L E C; Chan, E K L; Mahler, M; Meroni, P L; Pruijn, G J M; Steiner, G; Shoenfeld, Y

2016-07-01

Testing for autoantibodies (AABs) is becoming more and more relevant, not only for diagnosing autoimmune diseases (AIDs) but also for the differentiation of defined AID subtypes with different clinical manifestations, course and prognosis as well as the very early diagnosis for adequate management in the context of personalized medicine. A major challenge to improve diagnostic accuracy is to harmonize or even standardize AAB analyses. This review presents the results of the 12th Dresden Symposium on Autoantibodies that focused on several aspects of improving autoimmune diagnostics. Topics that are addressed include the International Consensus on ANA Patterns (ICAP) and the International Autoantibody Standardization (IAS) initiatives, the optimization of diagnostic algorithms, the description and evaluation of novel disease-specific AABs as well as the development and introduction of novel assays into routine diagnostics. This review also highlights important developments of recent years, most notably the improvement in diagnosing and predicting the course of rheumatoid arthritis, systemic sclerosis, idiopathic inflammatory myopathies, and of autoimmune neurological, gastrointestinal and liver diseases; the potential diagnostic role of anti-DFS70 antibodies and tumor-associated AABs. Furthermore, some hot topics in autoimmunity regarding disease pathogenesis and management are described. © The Author(s) 2016.

Rapid DNA extraction from dried blood spots on filter paper: potential applications in biobanking.

PubMed

Choi, Eun-Hye; Lee, Sang Kwang; Ihm, Chunhwa; Sohn, Young-Hak

2014-12-01

Dried blood spot (DBS) technology is a microsampling alternative to traditional plasma or serum sampling for pharmaco- or toxicokinetic evaluation. DBS technology has been applied to diagnostic screening in drug discovery, nonclinical, and clinical settings. We have developed an improved elution protocol involving boiling of blood spots dried on Whatman filter paper. The purpose of this study was to compare the quality, purity, and quantity of DNA isolated from frozen blood samples and DBSs. We optimized a method for extraction and estimation of DNA from blood spots dried on filter paper (3-mm FTA card). A single DBS containing 40 μL blood was used. DNA was efficiently extracted in phosphate-buffered saline (PBS) or Tris-EDTA (TE) buffer by incubation at 37°C overnight. DNA was stable in DBSs that were stored at room temperature or frozen. The housekeeping genes GAPDH and beta-actin were used as positive standards for polymerase chain reaction (PCR) validation of general diagnostic screening. Our simple and convenient DBS storage and extraction methods are suitable for diagnostic screening by using very small volumes of blood collected on filter paper, and can be used in biobanks for blood sample storage.

A feasability study of color flow doppler vectorization for automated blood flow monitoring.

PubMed

Schorer, R; Badoual, A; Bastide, B; Vandebrouck, A; Licker, M; Sage, D

2017-12-01

An ongoing issue in vascular medicine is the measure of the blood flow. Catheterization remains the gold standard measurement method, although non-invasive techniques are an area of intense research. We hereby present a computational method for real-time measurement of the blood flow from color flow Doppler data, with a focus on simplicity and monitoring instead of diagnostics. We then analyze the performance of a proof-of-principle software implementation. We imagined a geometrical model geared towards blood flow computation from a color flow Doppler signal, and we developed a software implementation requiring only a standard diagnostic ultrasound device. Detection performance was evaluated by computing flow and its determinants (flow speed, vessel area, and ultrasound beam angle of incidence) on purposely designed synthetic and phantom-based arterial flow simulations. Flow was appropriately detected in all cases. Errors on synthetic images ranged from nonexistent to substantial depending on experimental conditions. Mean errors on measurements from our phantom flow simulation ranged from 1.2 to 40.2% for angle estimation, and from 3.2 to 25.3% for real-time flow estimation. This study is a proof of concept showing that accurate measurement can be done from automated color flow Doppler signal extraction, providing the industry the opportunity for further optimization using raw ultrasound data.

Osteosarcoma Overview.

PubMed

Lindsey, Brock A; Markel, Justin E; Kleinerman, Eugenie S

2017-06-01

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Surface electromyography as a screening method for evaluation of dysphagia and odynophagia

PubMed Central

Vaiman, Michael; Eviatar, Ephraim

2009-01-01

Objective Patients suspected of having swallowing disorders, could highly benefit from simple diagnostic screening before being referred to specialist evaluations. The article analyzes various instrumental methods of dysphagia assessment, introduces surface electromyography (sEMG) to carry out rapid assessment of such patients, and debates proposed suggestions for sEMG screening protocol in order to identify abnormal deglutition. Data sources Subject related books and articles from 1813 to 2007 were obtained through library search, MEDLINE (1949–2007) and EMBASE (1975–2007). Methods Specifics steps for establishing the protocol for applying the technique for screening purposes (e.g., evaluation of specific muscles), the requirements for diagnostic sEMG equipment, the sEMG technique itself, and defining the tests suitable for assessing deglutition (e.g., saliva, normal, and excessive swallows and uninterrupted drinking of water) are presented in detail. SEMG is compared with other techniques in terms of cost, timing, involvement of radiation, etc. Results According to the published data, SEMG of swallowing is a simple and reliable method for screening and preliminary differentiation among dysphagia and odynophagia of various origins. This noninvasive radiation-free examination has a low level of discomfort, and is simple, time-saving and inexpensive to perform. The major weakness of the method seems to be inability for precise diagnostic of neurologically induced dysphagia. Conclusion With standardization of the technique and an established normative database, sEMG might serve as a reliable screening method for optimal patient management but cannot serve for proper investigation of neurogenic dysphagia. PMID:19232090

Accuracy of imaging methods for detection of bone tissue invasion in patients with oral squamous cell carcinoma

PubMed Central

Uribe, S; Rojas, LA; Rosas, CF

2013-01-01

The objective of this review is to evaluate the diagnostic accuracy of imaging methods for detection of mandibular bone tissue invasion by squamous cell carcinoma (SCC). A systematic review was carried out of studies in MEDLINE, SciELO and ScienceDirect, published between 1960 and 2012, in English, Spanish or German, which compared detection of mandibular bone tissue invasion via different imaging tests against a histopathology reference standard. Sensitivity and specificity data were extracted from each study. The outcome measure was diagnostic accuracy. We found 338 articles, of which 5 fulfilled the inclusion criteria. Tests included were: CT (four articles), MRI (four articles), panoramic radiography (one article), positron emission tomography (PET)/CT (one article) and cone beam CT (CBCT) (one article). The quality of articles was low to moderate and the evidence showed that all tests have a high diagnostic accuracy for detection of mandibular bone tissue invasion by SCC, with sensitivity values of 94% (MRI), 91% (CBCT), 83% (CT) and 55% (panoramic radiography), and specificity values of 100% (CT, MRI, CBCT), 97% (PET/CT) and 91.7% (panoramic radiography). Available evidence is scarce and of only low to moderate quality. However, it is consistently shown that current imaging methods give a moderate to high diagnostic accuracy for the detection of mandibular bone tissue invasion by SCC. Recommendations are given for improving the quality of future reports, in particular provision of a detailed description of the patients' conditions, the imaging instrument and both imaging and histopathological invasion criteria. PMID:23420854

Accuracy of dementia diagnosis: a direct comparison between radiologists and a computerized method.

PubMed

Klöppel, Stefan; Stonnington, Cynthia M; Barnes, Josephine; Chen, Frederick; Chu, Carlton; Good, Catriona D; Mader, Irina; Mitchell, L Anne; Patel, Ameet C; Roberts, Catherine C; Fox, Nick C; Jack, Clifford R; Ashburner, John; Frackowiak, Richard S J

2008-11-01

There has been recent interest in the application of machine learning techniques to neuroimaging-based diagnosis. These methods promise fully automated, standard PC-based clinical decisions, unbiased by variable radiological expertise. We recently used support vector machines (SVMs) to separate sporadic Alzheimer's disease from normal ageing and from fronto-temporal lobar degeneration (FTLD). In this study, we compare the results to those obtained by radiologists. A binary diagnostic classification was made by six radiologists with different levels of experience on the same scans and information that had been previously analysed with SVM. SVMs correctly classified 95% (sensitivity/specificity: 95/95) of sporadic Alzheimer's disease and controls into their respective groups. Radiologists correctly classified 65-95% (median 89%; sensitivity/specificity: 88/90) of scans. SVM correctly classified another set of sporadic Alzheimer's disease in 93% (sensitivity/specificity: 100/86) of cases, whereas radiologists ranged between 80% and 90% (median 83%; sensitivity/specificity: 80/85). SVMs were better at separating patients with sporadic Alzheimer's disease from those with FTLD (SVM 89%; sensitivity/specificity: 83/95; compared to radiological range from 63% to 83%; median 71%; sensitivity/specificity: 64/76). Radiologists were always accurate when they reported a high degree of diagnostic confidence. The results show that well-trained neuroradiologists classify typical Alzheimer's disease-associated scans comparable to SVMs. However, SVMs require no expert knowledge and trained SVMs can readily be exchanged between centres for use in diagnostic classification. These results are encouraging and indicate a role for computerized diagnostic methods in clinical practice.

Accuracy of dementia diagnosis—a direct comparison between radiologists and a computerized method

PubMed Central

Stonnington, Cynthia M.; Barnes, Josephine; Chen, Frederick; Chu, Carlton; Good, Catriona D.; Mader, Irina; Mitchell, L. Anne; Patel, Ameet C.; Roberts, Catherine C.; Fox, Nick C.; Jack, Clifford R.; Ashburner, John; Frackowiak, Richard S. J.

2008-01-01

There has been recent interest in the application of machine learning techniques to neuroimaging-based diagnosis. These methods promise fully automated, standard PC-based clinical decisions, unbiased by variable radiological expertise. We recently used support vector machines (SVMs) to separate sporadic Alzheimer's disease from normal ageing and from fronto-temporal lobar degeneration (FTLD). In this study, we compare the results to those obtained by radiologists. A binary diagnostic classification was made by six radiologists with different levels of experience on the same scans and information that had been previously analysed with SVM. SVMs correctly classified 95% (sensitivity/specificity: 95/95) of sporadic Alzheimer's disease and controls into their respective groups. Radiologists correctly classified 65–95% (median 89%; sensitivity/specificity: 88/90) of scans. SVM correctly classified another set of sporadic Alzheimer's disease in 93% (sensitivity/specificity: 100/86) of cases, whereas radiologists ranged between 80% and 90% (median 83%; sensitivity/specificity: 80/85). SVMs were better at separating patients with sporadic Alzheimer's disease from those with FTLD (SVM 89%; sensitivity/specificity: 83/95; compared to radiological range from 63% to 83%; median 71%; sensitivity/specificity: 64/76). Radiologists were always accurate when they reported a high degree of diagnostic confidence. The results show that well-trained neuroradiologists classify typical Alzheimer's disease-associated scans comparable to SVMs. However, SVMs require no expert knowledge and trained SVMs can readily be exchanged between centres for use in diagnostic classification. These results are encouraging and indicate a role for computerized diagnostic methods in clinical practice. PMID:18835868

Patient dose measurement in common medical X-ray examinations and propose the first local dose reference levels to diagnostic radiology in Iran

NASA Astrophysics Data System (ADS)

Rasuli, Behrouz; Tabari Juybari, Raheleh; Forouzi, Meysam; Ghorbani, Mohammad

2017-09-01

Introduction: The main purpose of this study was to investigate patient dose in pelvic and abdomen x-ray examinations. This work also provided the LDRLs (local diagnostic reference levels) in Khuzestan region, southwest of Iran to help establish the NDRLs (national diagnostic reference levels). Methods: Patient doses were assessed from patient's anatomical data and exposure parameters based on the IAEA indirect dosimetry method. With regard to this method, exposure parameters such as tube output, kVp, mAs, FFD and patient anatomical data were used for calculating ESD (entrance skin dose) of patients. This study was conducted on 250 standard patients (50% men and 50% women) at eight high-patient-load imaging centers. Results: The results indicate that mean ESDs for the both pelvic and abdomen examinations were lower than the IAEA and EC reference levels, 2.3 and 3.7 mGy, respectively. Mean applied kVps were 67 and 70 and mean FFDs were 103 and 109, respectively. Tube loadings obtained in this study for pelvic examination were lower than all the corresponding values in the reviewed literature. Likewise, the average annual patient load across all hospitals were more than 37000 patients, i.e. more than 100 patients a day. Conclusions: The authors recommend that DRLs (diagnostic reference levels) obtained in this region, which are the first available data, can be used as local DRLs for pelvic and abdomen procedures. This work also provides that on-the-job training programs for staffs and close cross collaboration between physicists and physicians should be strongly considered.

Laser speckle imaging for lesion detection on tooth

NASA Astrophysics Data System (ADS)

Gavinho, Luciano G.; Silva, João. V. P.; Damazio, João. H.; Sfalcin, Ravana A.; Araujo, Sidnei A.; Pinto, Marcelo M.; Olivan, Silvia R. G.; Prates, Renato A.; Bussadori, Sandra K.; Deana, Alessandro M.

2018-02-01

Computer vision technologies for diagnostic imaging applied to oral lesions, specifically, carious lesions of the teeth, are in their early years of development. The relevance of this public problem, dental caries, worries countries around the world, as it affects almost the entire population, at least once in the life of each individual. The present work demonstrates current techniques for obtaining information about lesions on teeth by segmentation laser speckle imagens (LSI). Laser speckle image results from laser light reflection on a rough surface, and it was considered a noise but has important features that carry information about the illuminated surface. Even though these are basic images, only a few works have analyzed it by application of computer vision methods. In this article, we present the latest results of our group, in which Computer vision techniques were adapted to segment laser speckle images for diagnostic purposes. These methods are applied to the segmentation of images between healthy and lesioned regions of the tooth. These methods have proven to be effective in the diagnosis of early-stage lesions, often imperceptible in traditional diagnostic methods in the clinical practice. The first method uses first-order statistical models, segmenting the image by comparing the mean and standard deviation of the intensity of the pixels. The second method is based on the distance of the chi-square (χ2 ) between the histograms of the image, bringing a significant improvement in the precision of the diagnosis, while a third method introduces the use of fractal geometry, exposing, through of the fractal dimension, more precisely the difference between lesioned areas and healthy areas of a tooth compared to other methods of segmentation. So far, we can observe efficiency in the segmentation of the carious regions. A software was developed for the execution and demonstration of the applicability of the models

Improvement of malaria diagnostic system based on acridine orange staining.

PubMed

Kimura, Masatsugu; Teramoto, Isao; Chan, Chim W; Idris, Zulkarnain Md; Kongere, James; Kagaya, Wataru; Kawamoto, Fumihiko; Asada, Ryoko; Isozumi, Rie; Kaneko, Akira

2018-02-07

Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent. The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya. Without staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard. Consistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.

Evaluating a novel application of optical fibre evanescent field absorbance: rapid measurement of red colour in winegrape homogenates

NASA Astrophysics Data System (ADS)

Lye, Peter G.; Bradbury, Ronald; Lamb, David W.

Silica optical fibres were used to measure colour (mg anthocyanin/g fresh berry weight) in samples of red wine grape homogenates via optical Fibre Evanescent Field Absorbance (FEFA). Colour measurements from 126 samples of grape homogenate were compared against the standard industry spectrophotometric reference method that involves chemical extraction and subsequent optical absorption measurements of clarified samples at 520 nm. FEFA absorbance on homogenates at 520 nm (FEFA520h) was correlated with the industry reference method measurements of colour (R2 = 0.46, n = 126). Using a simple regression equation colour could be predicted with a standard error of cross-validation (SECV) of 0.21 mg/g, with a range of 0.6 to 2.2 mg anthocyanin/g and a standard deviation of 0.33 mg/g. With a Ratio of Performance Deviation (RPD) of 1.6, the technique when utilizing only a single detection wavelength, is not robust enough to apply in a diagnostic sense, however the results do demonstrate the potential of the FEFA method as a fast and low-cost assay of colour in homogenized samples.

Practice advisory: The utility of EEG theta/beta power ratio in ADHD diagnosis

PubMed Central

Gloss, David; Varma, Jay K.; Pringsheim, Tamara; Nuwer, Marc R.

2016-01-01

Objective: To evaluate the evidence for EEG theta/beta power ratio for diagnosing, or helping to diagnose, attention-deficit/hyperactivity disorder (ADHD). Methods: We identified relevant studies and classified them using American Academy of Neurology criteria. Results: Two Class I studies assessing the ability of EEG theta/beta power ratio and EEG frontal beta power to identify patients with ADHD correctly identified 166 of 185 participants. Both studies evaluated theta/beta power ratio and frontal beta power in suspected ADHD or in syndromes typically included in an ADHD differential diagnosis. A bivariate model combining the diagnostic studies shows that the combination of EEG frontal beta power and theta/beta power ratio has relatively high sensitivity and specificity but is insufficiently accurate. Conclusions: It is unknown whether a combination of standard clinical examination and EEG theta/beta power ratio increases diagnostic certainty of ADHD compared with clinical examination alone. Recommendations: Level B: Clinicians should inform patients with suspected ADHD and their families that the combination of EEG theta/beta power ratio and frontal beta power should not replace a standard clinical evaluation. There is a risk for significant harm to patients from ADHD misdiagnosis because of the unacceptably high false-positive diagnostic rate of EEG theta/beta power ratio and frontal beta power. Level R: Clinicians should inform patients with suspected ADHD and their families that the EEG theta/beta power ratio should not be used to confirm an ADHD diagnosis or to support further testing after a clinical evaluation, unless such diagnostic assessments occur in a research setting. PMID:27760867

Diagnostic Differentiation of Autism Spectrum Disorders and Pragmatic Language Impairment

ERIC Educational Resources Information Center

Reisinger, Lisa M.; Cornish, Kim M.; Fombonne, Eric

2011-01-01

The present study examined diagnostic differentiation between school-aged children with autism spectrum disorders (ASD) and children with pragmatic language impairment (PLI). Standardized diagnostic instruments were used to investigate the relationship between severity of "autism triad" impairments and group membership. The Autism Diagnostic…

The 2002 NIMH Provisional Diagnostic Criteria for Depression of Alzheimer's Disease (PDC-dAD): Gauging their Validity over a Decade Later.

PubMed

Sepehry, Amir A; Lee, Philip E; Hsiung, Ging-Yuek R; Beattie, B Lynn; Feldman, Howard H; Jacova, Claudia

2017-01-01

Presented herein is evidence for criterion, content, and convergent/discriminant validity of the NIMH-Provisional Diagnostic Criteria for depression of Alzheimer's Disease (PDC-dAD) that were formulated to address depression in Alzheimer's disease (AD). Using meta-analytic and systematic review methods, we examined criterion validity evidence in epidemiological and clinical studies comparing the PDC-dAD to Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV), and International Classification of Disease (ICD 9) depression diagnostic criteria. We estimated prevalence of depression by PDC, DSM, and ICD with an omnibus event rate effect-size. We also examined diagnostic agreement between PDC and DSM. To gauge content validity, we reviewed rates of symptom endorsement for each diagnostic approach. Finally, we examined the PDC's relationship with assessment scales (global cognition, neuropsychiatric, and depression definition) for convergent validity evidence. The aggregate evidence supports the validity of the PDC-dAD. Our findings suggest that depression in AD differs from other depressive disorders including Major Depressive Disorder (MDD) in that dAD is more prevalent, with generally a milder presentation and with unique features not captured by the DSM. Although the PDC are the current standard for diagnosis of depression in AD, we identified the need for their further optimization based on predictive validity evidence.

Diagnostic sensitivity of abdominal fat aspiration in cardiac amyloidosis

PubMed Central

Quarta, Candida Cristina; Gonzalez-Lopez, Esther; Gilbertson, Janet A.; Botcher, Nichola; Rowczenio, Dorota; Petrie, Aviva; Rezk, Tamer; Youngstein, Taryn; Mahmood, Shameem; Sachchithanantham, Sajitha; Lachmann, Helen J.; Fontana, Marianna; Whelan, Carol J.; Wechalekar, Ashutosh D.; Hawkins, Philip N.; Gillmore, Julian D.

2017-01-01

Abstract Aims Congo red staining of an endomyocardial biopsy is the diagnostic gold-standard in suspected cardiac amyloidosis (CA), but the procedure is associated with the risk, albeit small, of serious complications, and delay in diagnosis due to the requirement for technical expertise. In contrast, abdominal fat pad fine needle aspiration (FPFNA) is a simple, safe and well-established procedure in systemic amyloidosis, but its diagnostic sensitivity in patients with suspected CA remains unclear. Methods and results We assessed the diagnostic sensitivity of FPFNA in 600 consecutive patients diagnosed with CA [216 AL amyloidosis, 113 hereditary transthyretin (ATTRm), and 271 wild-type transthyretin (ATTRwt) amyloidosis] at our Centre. Amyloid was detected on Congo red staining of FPFNAs in 181/216 (84%) patients with cardiac AL amyloidosis, including 100, 97, and 78% of those with a large, moderate, and small whole-body amyloid burden, respectively, as assessed by serum amyloid P (SAP) component scintigraphy (P < 0.001); the deposits were successfully typed as AL by immunohistochemistry in 102/216 (47%) cases. Amyloid was detected in FPFNAs of 51/113 (45%) patients with ATTRm CA, and only 42/271 (15%) cases with ATTRwt CA. Conclusions FPFNA has reasonable diagnostic sensitivity in cardiac AL amyloidosis, particularly in patients with a large whole-body amyloid burden. Although the diagnostic sensitivity of FPFNA is substantially lower in transthyretin CA, particularly ATTRwt, it may nevertheless sometimes obviate the need for endomyocardial biopsy. PMID:28605421

A systematic review of methods to diagnose oral dryness and salivary gland function

PubMed Central

2012-01-01

Background The most advocated clinical method for diagnosing salivary dysfunction is to quantitate unstimulated and stimulated whole saliva (sialometry). Since there is an expected and wide variation in salivary flow rates among individuals, the assessment of dysfunction can be difficult. The aim of this systematic review is to evaluate the quality of the evidence for the efficacy of diagnostic methods used to identify oral dryness. Methods A literature search, with specific indexing terms and a hand search, was conducted for publications that described a method to diagnose oral dryness. The electronic databases of PubMed, Cochrane Library, and Web of Science were used as data sources. Four reviewers selected publications on the basis of predetermined inclusion and exclusion criteria. Data were extracted from the selected publications using a protocol. Original studies were interpreted with the aid of Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Results The database searches resulted in 224 titles and abstracts. Of these abstracts, 80 publications were judged to meet the inclusion criteria and read in full. A total of 18 original studies were judged relevant and interpreted for this review. In all studies, the results of the test method were compared to those of a reference method. Based on the interpretation (with the aid of the QUADAS tool) it can be reported that the patient selection criteria were not clearly described and the test or reference methods were not described in sufficient detail for it to be reproduced. None of the included studies reported information on uninterpretable/intermediate results nor data on observer or instrument variation. Seven of the studies presented their results as a percentage of correct diagnoses. Conclusions The evidence for the efficacy of clinical methods to assess oral dryness is sparse and it can be stated that improved standards for the reporting of diagnostic accuracy are needed in order to assure the methodological quality of studies. There is need for effective diagnostic criteria and functional tests in order to detect those individuals with oral dryness who may require oral treatment, such as alleviation of discomfort and/or prevention of diseases. PMID:22870895

Partial verification bias and incorporation bias affected accuracy estimates of diagnostic studies for biomarkers that were part of an existing composite gold standard.

PubMed

Karch, Annika; Koch, Armin; Zapf, Antonia; Zerr, Inga; Karch, André

2016-10-01

To investigate how choice of gold standard biases estimates of sensitivity and specificity in studies reassessing the diagnostic accuracy of biomarkers that are already part of a lifetime composite gold standard (CGS). We performed a simulation study based on the real-life example of the biomarker "protein 14-3-3" used for diagnosing Creutzfeldt-Jakob disease. Three different types of gold standard were compared: perfect gold standard "autopsy" (available in a small fraction only; prone to partial verification bias), lifetime CGS (including the biomarker under investigation; prone to incorporation bias), and "best available" gold standard (autopsy if available, otherwise CGS). Sensitivity was unbiased when comparing 14-3-3 with autopsy but overestimated when using CGS or "best available" gold standard. Specificity of 14-3-3 was underestimated in scenarios comparing 14-3-3 with autopsy (up to 24%). In contrast, overestimation (up to 20%) was observed for specificity compared with CGS; this could be reduced to 0-10% when using the "best available" gold standard. Choice of gold standard affects considerably estimates of diagnostic accuracy. Using the "best available" gold standard (autopsy where available, otherwise CGS) leads to valid estimates of specificity, whereas sensitivity is estimated best when tested against autopsy alone. Copyright © 2016 Elsevier Inc. All rights reserved.

Reductions in Diagnostic Imaging With High Deductible Health Plans.

PubMed

Zheng, Sarah; Ren, Zhong Justin; Heineke, Janelle; Geissler, Kimberley H

2016-02-01

Diagnostic imaging utilization grew rapidly over the past 2 decades. It remains unclear whether patient cost-sharing is an effective policy lever to reduce imaging utilization and spending. Using 2010 commercial insurance claims data of >21 million individuals, we compared diagnostic imaging utilization and standardized payments between High Deductible Health Plan (HDHP) and non-HDHP enrollees. Negative binomial models were used to estimate associations between HDHP enrollment and utilization, and were repeated for standardized payments. A Hurdle model were used to estimate associations between HDHP enrollment and whether an enrollee had diagnostic imaging, and then the magnitude of associations for enrollees with imaging. Models with interaction terms were used to estimate associations between HDHP enrollment and imaging by risk score tercile. All models included controls for patient age, sex, geographic location, and health status. HDHP enrollment was associated with a 7.5% decrease in the number of imaging studies and a 10.2% decrease in standardized imaging payments. HDHP enrollees were 1.8% points less likely to use imaging; once an enrollee had at least 1 imaging study, differences in utilization and associated payments were small. Associations between HDHP and utilization were largest in the lowest (least sick) risk score tercile. Increased patient cost-sharing may contribute to reductions in diagnostic imaging utilization and spending. However, increased cost-sharing may not encourage patients to differentiate between high-value and low-value diagnostic imaging services; better patient awareness and education may be a crucial part of any reductions in diagnostic imaging utilization.

Accuracy of Immunofluorescence in the Diagnosis of Primary Ciliary Dyskinesia

PubMed Central

Frost, Emily; Dixon, Mellisa; Ollosson, Sarah; Kilpin, Kate; Patel, Mitali; Scully, Juliet; Rogers, Andrew V.; Mitchison, Hannah M.; Bush, Andrew; Hogg, Claire

2017-01-01

Rationale: The standard approach to diagnosis of primary ciliary dyskinesia (PCD) in the United Kingdom consists of assessing ciliary function by high-speed microscopy and ultrastructure by election microscopy, but equipment and expertise is not widely available internationally. The identification of biallelic disease-causing mutations is also diagnostic, but many disease-causing genes are unknown, and testing is not widely available outside the United States. Fluorescent antibodies to ciliary proteins are used to validate research genetic studies, but diagnostic utility in this disease has not been systematically evaluated. Objectives: To determine utility of a panel of six fluorescent labeled antibodies as a diagnostic tool for PCD. Methods: The study used immunofluorescent labeling of nasal brushings from a discovery cohort of 35 patients diagnosed with PCD by ciliary ultrastructure, and a diagnostic accuracy cohort of 386 patients referred with symptoms suggestive of disease. The results were compared with diagnostic outcome. Measurements and Main Results: Immunofluorescence correctly identified mislocalized or absent staining in 100% of the discovery cohort. In the diagnostic cohort immunofluorescence successfully identified 22 of 25 patients with PCD and normal staining in all 252 in whom PCD was considered highly unlikely. In addition, immunofluorescence provided a result in 55% (39) of cases that were previously inconclusive. Immunofluorescence results were available within 14 days, costing $187 per sample compared with electron microscopy (27 days; cost $1,452). Conclusions: Immunofluorescence is a highly specific diagnostic test for PCD, and it improves the speed and availability of diagnostic testing. However, sensitivity is limited and immunofluorescence is not suitable as a stand-alone test. PMID:28199173

Evidence and diagnostic reporting in the IHE context.

PubMed

Loef, Cor; Truyen, Roel

2005-05-01

Capturing clinical observations and findings during the diagnostic imaging process is increasingly becoming a critical step in diagnostic reporting. Standards developers-notably HL7 and DICOM-are making significant progress toward standards that enable exchanging clinical observations and findings among the various information systems of the healthcare enterprise. DICOM-like the HL7 Clinical Document Architecture (CDA) -uses templates and constrained, coded vocabulary (SNOMED, LOINC, etc.). Such a representation facilitates automated software recognition of findings and observations, intrapatient comparison, correlation to norms, and outcomes research. The scope of DICOM Structured Reporting (SR) includes many findings that products routinely create in digital form (measurements, computed estimates, etc.). In the Integrating the Healthcare Enterprise (IHE) framework, two Integration Profiles are defined for clinical data capture and diagnostic reporting: Evidence Document, and Simple Image and Numeric Report. This report describes these two DICOM SR-based integration profiles in the diagnostic reporting process.

Current challenges in diagnostic imaging of venous thromboembolism.

PubMed

Huisman, Menno V; Klok, Frederikus A

2015-01-01

Because the clinical diagnosis of deep-vein thrombosis and pulmonary embolism is nonspecific, integrated diagnostic approaches for patients with suspected venous thromboembolism have been developed over the years, involving both non-invasive bedside tools (clinical decision rules and D-dimer blood tests) for patients with low pretest probability and diagnostic techniques (compression ultrasound for deep-vein thrombosis and computed tomography pulmonary angiography for pulmonary embolism) for those with a high pretest probability. This combination has led to standardized diagnostic algorithms with proven safety for excluding venous thrombotic disease. At the same time, it has become apparent that, as a result of the natural history of venous thrombosis, there are special patient populations in which the current standard diagnostic algorithms are not sufficient. In this review, we present 3 evidence-based patient cases to underline recent developments in the imaging diagnosis of venous thromboembolism. © 2015 by The American Society of Hematology. All rights reserved.

A combined strategy for screening a clustered mobile population returning from highly endemic areas for Plasmodium falciparum.

PubMed

Li, Mei; Li, Jun; Xia, Zhigui; Xiao, Ning; Jiang, Weikang; Wen, Yongkang

2017-04-30

Early and accurate diagnosis of imported malaria cases in clusters is crucial for protecting the health of patients and local populations, especially confirmed parasitic persons who are asymptomatic. A total of 226 gold miners who had stayed in highly endemic areas of Ghana for more than six months and returned in clusters were selected randomly. Blood samples from them were tested with microscopy, nest polymerase chain reaction, and rapid diagnostic test (RDT). The sensitivity, specificity, predictive values, agreement rate, and Youden's index of each of three diagnostic methods were calculated and compared with the defined gold standard. A quick and efficient way to respond to screening such a clustered mobile population was predicted and analyzed by evaluating two assumed results of combining microscopy and RDT with or without symptoms of illness. The rate of the carriers of malaria parasites in the populations of gold miners was 19.47%, including 39 P. falciparum. Among the three diagnostic methods, the microscopy method showed the highest specificity, while the RDT method showed the highest sensitivity but the lowest specificity in detecting P. falciparum. The assumed results of combining RDT and microscopy with symptoms showed the best results among all the test results in screening P. falciparum. It was too complex and difficult to catch all parasite carriers in a short period of time among populations with such a complicated situation as that in Shanglin County. A strategy of combing microscopy and RDT for diagnosis is highly recommended.

Preliminary evaluation of the impact of a Web-based HIV testing programme in Abruzzo Region on the prevention of late HIV presentation and associated mortality.

PubMed

Polilli, Ennio; Sozio, Federica; Di Stefano, Paola; Clerico, Luigi; Di Iorio, Giancarlo; Parruti, Giustino

2018-04-01

This study aimed to analyze the efficacy of a Web-based testing programme in terms of the prevention of late HIV presentation. The clinical characteristics of patients diagnosed with HIV via the Web-based testing programme were compared to those of patients diagnosed in parallel via standard diagnostic care procedures. This study included the clinical and demographic data of newly diagnosed HIV patients enrolled at the study clinic between February 2014 and June 2017. These patients were diagnosed either via standard diagnostic procedures or as a result of the Web-based testing programme. Eighty-eight new cases of HIV were consecutively enrolled; their mean age was 39.1±13.0 years. Fifty-nine patients (67%) were diagnosed through standard diagnostic procedures and 29 (33%) patients came from the Web-based testing programme. Late presentation (62% vs. 34%, p=0.01) and AIDS-defining conditions at presentation (13 vs. 1, p=0.02) were significantly more frequent in the standard care group than in the Web-based group; four of 13 patients with AIDS diagnosed under standard diagnostic procedures died, versus none in the Web-based testing group (p<0.001). Web-based recruitment for voluntary and free HIV testing helped to diagnose patients with less advanced HIV disease and no risk of death, from all at-risk groups, in comparison with standard care testing. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Diagnostic performance of BMI percentiles to identify adolescents with metabolic syndrome.

PubMed

Laurson, Kelly R; Welk, Gregory J; Eisenmann, Joey C

2014-02-01

To compare the diagnostic performance of the Centers for Disease Control and Prevention (CDC) and FITNESSGRAM (FGram) BMI standards for quantifying metabolic risk in youth. Adolescents in the NHANES (n = 3385) were measured for anthropometric variables and metabolic risk factors. BMI percentiles were calculated, and youth were categorized by weight status (using CDC and FGram thresholds). Participants were also categorized by presence or absence of metabolic syndrome. The CDC and FGram standards were compared by prevalence of metabolic abnormalities, various diagnostic criteria, and odds of metabolic syndrome. Receiver operating characteristic curves were also created to identify optimal BMI percentiles to detect metabolic syndrome. The prevalence of metabolic syndrome in obese youth was 19% to 35%, compared with <2% in the normal-weight groups. The odds of metabolic syndrome for obese boys and girls were 46 to 67 and 19 to 22 times greater, respectively, than for normal-weight youth. The receiver operating characteristic analyses identified optimal thresholds similar to the CDC standards for boys and the FGram standards for girls. Overall, BMI thresholds were more strongly associated with metabolic syndrome in boys than in girls. Both the CDC and FGram standards are predictive of metabolic syndrome. The diagnostic utility of the CDC thresholds outperformed the FGram values for boys, whereas FGram standards were slightly better thresholds for girls. The use of a common set of thresholds for school and clinical applications would provide advantages for public health and clinical research and practice.

Role of imprint cytology in intra operative diagnosis of thyroid lesions.

PubMed

Anila, K R; Krishna, G

2014-07-01

Intra-operative imprint cytology is an important diagnostic modality in the diagnosis of thyroid lesions. A correct intra-operative diagnosis helps eliminate the need for second surgery. To study diagnostic accuracy of imprint cytology and to compare the imprint cytology results with that of the corresponding paraffin section diagnosis in thyroidectomy cases. This is a prospective study of 84 patients who have undergone thyroidectomies over a period of one year at the Department of Surgery, Thiruvananthapuram, Kerala, India. The intraoperative imprint cytology smears were stained by Papanicolaou method. The imprint cytology interpretation was later compared with the paraffin section diagnosis. Of the 84 patients using haematoxylin and eosin stained histopathology sections as the gold standard, the diagnostic sensitivity of imprint cytology was 75% and specificity was 100%. Positive predictive value was 100%. Negative predictive value was 98.74%. Imprint cytology has high sensitivity and specificity in diagnosing lesions of the thyroid. The problems faced were in diagnosing follicular carcinomas and differentiating low grade lymphoma from lymphocytic thyroiditis. Imprint cytology is a simple, reliable diagnostic technique. It has high sensitivity and specificity in intra-operative diagnosis of lesions of thyroid. In spite of the advent of newer diagnostic modalities like frozen sections, imprint cytology still holds its unique position in the current perspective.

Use of PCR in resolving diagnostic difficulties potentially caused by genetic variation of hepatitis B virus.

PubMed Central

van Deursen, F J; Hino, K; Wyatt, D; Molyneaux, P; Yates, P; Wallace, L A; Dow, B C; Carman, W F

1998-01-01

AIMS: To assess the relevance of genetic variants of hepatitis B virus (HBV) and to demonstrate the usefulness of the polymerase chain reaction (PCR) in cases of HBV diagnostic difficulty. METHODS: Five serum samples from patients that presented diagnostic difficulty in routine laboratories were sent to a research laboratory for PCR, and if appropriate, S gene sequencing, in vitro expression, and antigenic analysis. RESULTS: The demonstration of HBV in serum by PCR allowed a definitive diagnosis of current infection. One serum sample with poor reactivity in a diagnostic assay had a minor hepatitis B surface antigen (HBsAg) variant and another with very poor reactivity had multiple variants of HBsAg. Transient HBsAg reactivity was observed in a recently vaccinated patient. A hepatitis Be antigen (HBeAg) false positive reaction was noted in a patient from a well defined risk group for HBV. One patient who was strongly HBsAg/HBeAg positive, but anti-hepatitis B core antibody negative, was viraemic. CONCLUSIONS: PCR may become the gold standard for the diagnosis of current HBV infection. HBV variants are responsible for a proportion of diagnostically difficult cases. Modification of commercial assays is necessary to increase the sensitivity of detection of such variants. PMID:9602690

Diagnostic methodology is critical for accurately determining the prevalence of ichthyophonus infections in wild fish populations

USGS Publications Warehouse

Kocan, R.; Dolan, H.; Hershberger, P.

2011-01-01

Several different techniques have been employed to detect and identify Ichthyophonus spp. in infected fish hosts; these include macroscopic observation, microscopic examination of tissue squashes, histological evaluation, in vitro culture, and molecular techniques. Examination of the peer-reviewed literature revealed that when more than 1 diagnostic method is used, they often result in significantly different results; for example, when in vitro culture was used to identify infected trout in an experimentally exposed population, 98.7% of infected trout were detected, but when standard histology was used to confirm known infected tissues from wild salmon, it detected ~50% of low-intensity infections and ~85% of high-intensity infections. Other studies on different species reported similar differences. When we examined a possible mechanism to explain the disparity between different diagnostic techniques, we observed non-random distribution of the parasite in 3-dimensionally visualized tissue sections from infected hosts, thus providing a possible explanation for the different sensitivities of commonly used diagnostic techniques. Based on experimental evidence and a review of the peer-reviewed literature, we have concluded that in vitro culture is currently the most accurate diagnostic technique for determining infection prevalence of Ichthyophonus, particularly when the exposure history of the population is not known.

Epidemiological and Clinical Features of Brucellosis in the Country of Georgia

PubMed Central

Akhvlediani, Tamar; Bautista, Christian T.; Garuchava, Natalia; Sanodze, Lia; Kokaia, Nora; Malania, Lile; Chitadze, Nazibrola; Sidamonidze, Ketevan; Rivard, Robert G.; Hepburn, Matthew J.; Nikolich, Mikeljon P.; Imnadze, Paata; Trapaidze, Nino

2017-01-01

Background Brucellosis is an endemic disease in the country of Georgia. According to the National Center for Disease Control and Public Health of Georgia (NCDC), the average annual number of brucellosis cases was 161 during 2008–2012. However, the true number of cases is thought to be higher due to underreporting. The aim of this study was to provide current epidemiological and clinical information and evaluate diagnostic methods used for brucellosis in Georgia. Methodology Adult patients were eligible for participation if they met the suspected or probable case definition for brucellosis. After consent participants were interviewed using a standardized questionnaire to collect information on socio-demographic characteristics, epidemiology, history of present illness, and clinical manifestation. For the diagnosis of brucellosis, culture and serological tests were used. Results A total of 81 participants were enrolled, of which 70 (86%) were from rural areas. Seventy-four percent of participants reported consuming unpasteurized milk products and 62% consuming undercooked meat products before symptom onset. Forty-one participants were positive by the Wright test and 33 (41%) were positive by blood culture. There was perfect agreement between the Huddelston and Wright tests (k = 1.0). Compared with blood culture (the diagnostic gold standard), ELISA IgG and total ELISA (IgG + IgM), the Wright test had fair (k = 0.12), fair (k = 0.24), and moderate (k = 0.52) agreement, respectively. Conclusions Consumption of unpasteurized milk products and undercooked meat were among the most common risk factors in brucellosis cases. We found poor agreement between ELISA tests and culture results. This report also serves as an initial indication that the suspected case definition for brucellosis surveillance purposes needs revision. Further research is needed to characterize the epidemiology and evaluate the performance of the diagnostic methods for brucellosis in Georgia. PMID:28107444

Quality in the molecular microbiology laboratory.

PubMed

Wallace, Paul S; MacKay, William G

2013-01-01

In the clinical microbiology laboratory advances in nucleic acid detection, quantification, and sequence analysis have led to considerable improvements in the diagnosis, management, and monitoring of infectious diseases. Molecular diagnostic methods are routinely used to make clinical decisions based on when and how to treat a patient as well as monitor the effectiveness of a therapeutic regime and identify any potential drug resistant strains that may impact on the long term patient treatment program. Therefore, confidence in the reliability of the result provided by the laboratory service to the clinician is essential for patient treatment. Hence, suitable quality assurance and quality control measures are important to ensure that the laboratory methods and service meet the necessary regulatory requirements both at the national and international level. In essence, the modern clinical microbiology laboratory ensures the appropriateness of its services through a quality management system that monitors all aspects of the laboratory service pre- and post-analytical-from patient sample receipt to reporting of results, from checking and upholding staff competency within the laboratory to identifying areas for quality improvements within the service offered. For most European based clinical microbiology laboratories this means following the common International Standard Organization (ISO9001) framework and ISO15189 which sets out the quality management requirements for the medical laboratory (BS EN ISO 15189 (2003) Medical laboratories-particular requirements for quality and competence. British Standards Institute, Bristol, UK). In the United States clinical laboratories performing human diagnostic tests are regulated by the Centers for Medicare and Medicaid Services (CMS) following the requirements within the Clinical Laboratory Improvement Amendments document 1988 (CLIA-88). This chapter focuses on the key quality assurance and quality control requirements within the modern microbiology laboratory providing molecular diagnostics.

Epidemiological and Clinical Features of Brucellosis in the Country of Georgia.

PubMed

Akhvlediani, Tamar; Bautista, Christian T; Garuchava, Natalia; Sanodze, Lia; Kokaia, Nora; Malania, Lile; Chitadze, Nazibrola; Sidamonidze, Ketevan; Rivard, Robert G; Hepburn, Matthew J; Nikolich, Mikeljon P; Imnadze, Paata; Trapaidze, Nino

2017-01-01

Brucellosis is an endemic disease in the country of Georgia. According to the National Center for Disease Control and Public Health of Georgia (NCDC), the average annual number of brucellosis cases was 161 during 2008-2012. However, the true number of cases is thought to be higher due to underreporting. The aim of this study was to provide current epidemiological and clinical information and evaluate diagnostic methods used for brucellosis in Georgia. Adult patients were eligible for participation if they met the suspected or probable case definition for brucellosis. After consent participants were interviewed using a standardized questionnaire to collect information on socio-demographic characteristics, epidemiology, history of present illness, and clinical manifestation. For the diagnosis of brucellosis, culture and serological tests were used. A total of 81 participants were enrolled, of which 70 (86%) were from rural areas. Seventy-four percent of participants reported consuming unpasteurized milk products and 62% consuming undercooked meat products before symptom onset. Forty-one participants were positive by the Wright test and 33 (41%) were positive by blood culture. There was perfect agreement between the Huddelston and Wright tests (k = 1.0). Compared with blood culture (the diagnostic gold standard), ELISA IgG and total ELISA (IgG + IgM), the Wright test had fair (k = 0.12), fair (k = 0.24), and moderate (k = 0.52) agreement, respectively. Consumption of unpasteurized milk products and undercooked meat were among the most common risk factors in brucellosis cases. We found poor agreement between ELISA tests and culture results. This report also serves as an initial indication that the suspected case definition for brucellosis surveillance purposes needs revision. Further research is needed to characterize the epidemiology and evaluate the performance of the diagnostic methods for brucellosis in Georgia.

Value of ultrasonography in the diagnosis of polycystic ovary syndrome - literature review.

PubMed

Bachanek, Michał; Abdalla, Nebil; Cendrowski, Krzysztof; Sawicki, Włodzimierz

2015-12-01

Polycystic ovary syndrome is a multi-factorial disease. Its etiopathogenesis has not been elucidated in detail. It is the most common endocrine disorder in women of child-bearing age. This disease entity is primarily characterized by disrupted ovulation and hyperandrogenism, but the clinical picture can be diversified and symptom intensity can vary. Currently, the sonographic assessment of ovaries is one of the obligatory criteria for the diagnosis of PCOS according to the Rotterdam consensus (2003) and Androgen Excess & PCOS Society (2006). This criterion is determined by the presence of ≥12 follicles within the ovary with a diameter of 2-9 mm and/or ovarian volume ≥10 cm(3). Such an ultrasound image in one gonad only is sufficient to define polycystic ovaries. The coexistence of polycystic ovaries with polycystic ovary syndrome is confirmed in over 90% of cases irrespective of ethnic factors or race. However, because of the commonness of ultrasound features of polycystic ovaries in healthy women, the inclusion of this sign to the diagnostic criteria of polycystic ovary syndrome is still questioned. The development of new technologies has an undoubted influence on the percentage of diagnosed polycystic ovaries. This process has caused an increase in the percentage of polycystic ovary diagnoses since the Rotterdam criteria were published. It is therefore needed to prepare new commonly accepted diagnostic norms concerning the number of ovarian follicles and the standardization of the technique in which they are counted. The assessment of anti-Müllerian hormone levels as an equivalent of ultrasound features of polycystic ovaries is a promising method. However, analytic methods have to be standardized in order to establish commonly accepted diagnostic norms.

Value of ultrasonography in the diagnosis of polycystic ovary syndrome – literature review

PubMed Central

Abdalla, Nebil; Cendrowski, Krzysztof; Sawicki, Włodzimierz

2015-01-01

Polycystic ovary syndrome is a multi-factorial disease. Its etiopathogenesis has not been elucidated in detail. It is the most common endocrine disorder in women of child-bearing age. This disease entity is primarily characterized by disrupted ovulation and hyperandrogenism, but the clinical picture can be diversified and symptom intensity can vary. Currently, the sonographic assessment of ovaries is one of the obligatory criteria for the diagnosis of PCOS according to the Rotterdam consensus (2003) and Androgen Excess & PCOS Society (2006). This criterion is determined by the presence of ≥12 follicles within the ovary with a diameter of 2–9 mm and/or ovarian volume ≥10 cm3. Such an ultrasound image in one gonad only is sufficient to define polycystic ovaries. The coexistence of polycystic ovaries with polycystic ovary syndrome is confirmed in over 90% of cases irrespective of ethnic factors or race. However, because of the commonness of ultrasound features of polycystic ovaries in healthy women, the inclusion of this sign to the diagnostic criteria of polycystic ovary syndrome is still questioned. The development of new technologies has an undoubted influence on the percentage of diagnosed polycystic ovaries. This process has caused an increase in the percentage of polycystic ovary diagnoses since the Rotterdam criteria were published. It is therefore needed to prepare new commonly accepted diagnostic norms concerning the number of ovarian follicles and the standardization of the technique in which they are counted. The assessment of anti-Müllerian hormone levels as an equivalent of ultrasound features of polycystic ovaries is a promising method. However, analytic methods have to be standardized in order to establish commonly accepted diagnostic norms. PMID:26807298

Combination of five diagnostic tests to estimate the prevalence of hookworm infection among school-aged children from a rural area of colombia.

PubMed

Barreto, Rafael E; Narváez, Javier; Sepúlveda, Natalia A; Velásquez, Fabián C; Díaz, Sandra C; López, Myriam Consuelo; Reyes, Patricia; Moncada, Ligia I

2017-09-01

Public health programs for the control of soil-transmitted helminthiases require valid diagnostic tests for surveillance and parasitic control evaluation. However, there is currently no agreement about what test should be used as a gold standard for the diagnosis of hookworm infection. Still, in presence of concurrent data for multiple tests it is possible to use statistical models to estimate measures of test performance and prevalence. The aim of this study was to estimate the diagnostic accuracy of five parallel tests (direct microscopic examination, Kato-Katz, Harada-Mori, modified Ritchie-Frick, and culture in agar plate) to detect hookworm infections in a sample of school-aged children from a rural area in Colombia. We used both, a frequentist approach, and Bayesian latent class models to estimate the sensitivity and specificity of five tests for hookworm detection, and to estimate the prevalence of hookworm infection in absence of a Gold Standard. The Kato-Katz and agar plate methods had an overall agreement of 95% and kappa coefficient of 0.76. Different models estimated a sensitivity between 76% and 92% for the agar plate technique, and 52% to 87% for the Kato-Katz technique. The other tests had lower sensitivity. All tests had specificity between 95% and 98%. The prevalence estimated by the Kato-Katz and Agar plate methods for different subpopulations varied between 10% and 14%, and was consistent with the prevalence estimated from the combination of all tests. The Harada-Mori, Ritchie-Frick and direct examination techniques resulted in lower and disparate prevalence estimates. Bayesian approaches assuming imperfect specificity resulted in lower prevalence estimates than the frequentist approach. Copyright © 2017 Elsevier B.V. All rights reserved.

Calibration and diagnostic accuracy of simple flotation, McMaster and FLOTAC for parasite egg counts in sheep.

PubMed

Rinaldi, L; Coles, G C; Maurelli, M P; Musella, V; Cringoli, G

2011-05-11

The present study was aimed at carrying out a calibration and a comparison of diagnostic accuracy of three faecal egg counts (FEC) techniques, simple flotation, McMaster and FLOTAC, in order to find the best flotation solution (FS) for Dicrocoelium dendriticum, Moniezia expansa and gastrointestinal (GI) strongyle eggs, and to evaluate the influence of faecal preservation methods combined with FS on egg counts. Simple flotation failed to give satisfactory results with any samples. Overall, FLOTAC resulted in similar or higher eggs per gram of faeces (EPG) and lower coefficient of variation (CV) than McMaster. The "gold standard" for D. dendriticum was obtained with FLOTAC when using FS7 (EPG=219, CV=3.9%) and FS8 (EPG=226, CV=5.2%) on fresh faeces. The "gold standard" for M. expansa was obtained with FLOTAC, using FS3 (EPG=122, CV=4.1%) on fresh faeces. The "gold standard" for GI strongyles was obtained with FLOTAC when using FS5 (EPG=320, CV=4%) and FS2 (EPG=298, CV=5%). As regard to faecal preservation methods, formalin 5% and 10% or freezing showed performance similar to fresh faeces for eggs of D. dendriticum and M. expansa. However, these methods of preservation were not as successful with GI strongyle eggs. Vacuum packing with storage at +4°C permitted storage of GI strongyle eggs for up to 21 days prior to counting. Where accurate egg counts are required in ovine samples the optimum method of counting is the use of FLOTAC. In addition, we suggest the use of two solutions that are easy and cheap to purchase and prepare, saturated sodium chloride (FS2) for nematoda and cestoda eggs and saturated zinc sulphate (FS7) for trematoda eggs and nematoda larvae. Copyright © 2010 Elsevier B.V. All rights reserved.

Predicting acute uncomplicated urinary tract infection in women: a systematic review of the diagnostic accuracy of symptoms and signs.

PubMed

Giesen, Leonie G M; Cousins, Gráinne; Dimitrov, Borislav D; van de Laar, Floris A; Fahey, Tom

2010-10-24

Acute urinary tract infections (UTI) are one of the most common bacterial infections among women presenting to primary care. However, there is a lack of consensus regarding the optimal reference standard threshold for diagnosing UTI. The objective of this systematic review is to determine the diagnostic accuracy of symptoms and signs in women presenting with suspected UTI, across three different reference standards (10(2) or 10(3) or 10(5) CFU/ml). We also examine the diagnostic value of individual symptoms and signs combined with dipstick test results in terms of clinical decision making. Searches were performed through PubMed (1966 to April 2010), EMBASE (1973 to April 2010), Cochrane library (1973 to April 2010), Google scholar and reference checking.Studies that assessed the diagnostic accuracy of symptoms and signs of an uncomplicated UTI using a urine culture from a clean-catch or catherised urine specimen as the reference standard, with a reference standard of at least ≥ 10(2) CFU/ml were included. Synthesised data from a high quality systematic review were used regarding dipstick results. Studies were combined using a bivariate random effects model. Sixteen studies incorporating 3,711 patients are included. The weighted prior probability of UTI varies across diagnostic threshold, 65.1% at ≥ 10(2) CFU/ml; 55.4% at ≥ 10(3) CFU/ml and 44.8% at ≥ 10(2) CFU/ml ≥ 10(5) CFU/ml. Six symptoms are identified as useful diagnostic symptoms when a threshold of ≥ 10(2) CFU/ml is the reference standard. Presence of dysuria (+LR 1.30 95% CI 1.20-1.41), frequency (+LR 1.10 95% CI 1.04-1.16), hematuria (+LR 1.72 95%CI 1.30-2.27), nocturia (+LR 1.30 95% CI 1.08-1.56) and urgency (+LR 1.22 95% CI 1.11-1.34) all increase the probability of UTI. The presence of vaginal discharge (+LR 0.65 95% CI 0.51-0.83) decreases the probability of UTI. Presence of hematuria has the highest diagnostic utility, raising the post-test probability of UTI to 75.8% at ≥ 10(2) CFU/ml and 67.4% at ≥ 10(3) CFU/ml. Probability of UTI increases to 93.3% and 90.1% at ≥ 10(2) CFU/ml and ≥ 10(3) CFU/ml respectively when presence of hematuria is combined with a positive dipstick result for nitrites. Subgroup analysis shows improved diagnostic accuracy using lower reference standards ≥ 10(2) CFU/ml and ≥ 10(3) CFU/ml. Individual symptoms and signs have a modest ability to raise the pretest-risk of UTI. Diagnostic accuracy improves considerably when combined with dipstick tests particularly tests for nitrites.

Can Depression be Diagnosed by Response to Mother's Face? A Personalized Attachment-Based Paradigm for Diagnostic fMRI

PubMed Central

Zhang, Xian; Yaseen, Zimri S.; Galynker, Igor I.; Hirsch, Joy; Winston, Arnold

2011-01-01

Objective Objective measurement of depression remains elusive. Depression has been associated with insecure attachment, and both have been associated with changes in brain reactivity in response to viewing standard emotional and neutral faces. In this study, we developed a method to calculate predicted scores for the Beck Depression Inventory II (BDI-II) using personalized stimuli: fMRI imaging of subjects viewing pictures of their own mothers. Methods 28 female subjects ages 18–30 (14 healthy controls and 14 unipolar depressed diagnosed by MINI psychiatric interview) were scored on the Beck Depression Inventory II (BDI-II) and the Adult Attachment Interview (AAI) coherence of mind scale of global attachment security. Subjects viewed pictures of Mother (M), Friend (F) and Stranger (S), during functional magnetic resonance imaging (fMRI). Using a principal component regression method (PCR), a predicted Beck Depression Inventory II (BDI-II) score was obtained from activity patterns in the paracingulate gyrus (Brodmann area 32) and compared to clinical diagnosis and the measured BDI-II score. The same procedure was performed for AAI coherence of mind scores. Results Activity patterns in BA-32 identified depressed subjects. The categorical agreement between the derived BDI-II score (using the standard clinical cut-score of 14 on the BDI-II) and depression diagnosis by MINI psychiatric interview was 89%, with sensitivity 85.7% and specificity 92.8%. Predicted and measured BDI-II scores had a correlation of 0.55. Prediction of attachment security was not statistically significant. Conclusions Brain activity in response to viewing one's mother may be diagnostic of depression. Functional magnetic resonance imaging using personalized paradigms has the potential to provide objective assessments, even when behavioral measures are not informative. Further, fMRI based diagnostic algorithms may enhance our understanding of the neural mechanisms of depression by identifying distinctive neural features of the illness. PMID:22180777

AF-DHNN: Fuzzy Clustering and Inference-Based Node Fault Diagnosis Method for Fire Detection

PubMed Central

Jin, Shan; Cui, Wen; Jin, Zhigang; Wang, Ying

2015-01-01

Wireless Sensor Networks (WSNs) have been utilized for node fault diagnosis in the fire detection field since the 1990s. However, the traditional methods have some problems, including complicated system structures, intensive computation needs, unsteady data detection and local minimum values. In this paper, a new diagnosis mechanism for WSN nodes is proposed, which is based on fuzzy theory and an Adaptive Fuzzy Discrete Hopfield Neural Network (AF-DHNN). First, the original status of each sensor over time is obtained with two features. One is the root mean square of the filtered signal (FRMS), the other is the normalized summation of the positive amplitudes of the difference spectrum between the measured signal and the healthy one (NSDS). Secondly, distributed fuzzy inference is introduced. The evident abnormal nodes’ status is pre-alarmed to save time. Thirdly, according to the dimensions of the diagnostic data, an adaptive diagnostic status system is established with a Fuzzy C-Means Algorithm (FCMA) and Sorting and Classification Algorithm to reducing the complexity of the fault determination. Fourthly, a Discrete Hopfield Neural Network (DHNN) with iterations is improved with the optimization of the sensors’ detected status information and standard diagnostic levels, with which the associative memory is achieved, and the search efficiency is improved. The experimental results show that the AF-DHNN method can diagnose abnormal WSN node faults promptly and effectively, which improves the WSN reliability. PMID:26193280

Numerical prediction of pollutant dispersion and transport in an atmospheric boundary layer

NASA Astrophysics Data System (ADS)

Zeoli, Stéphanie; Bricteux, Laurent; Mech. Eng. Dpt. Team

2014-11-01

The ability to accurately predict concentration levels of air pollutant released from point sources is required in order to determine their environmental impact. A wall modeled large-eddy simulation (WMLES) of the ABL is performed using the OpenFoam based solver SOWFA (Churchfield and Lee, NREL). It uses Boussinesq approximation for buoyancy effects and takes into account Coriolis forces. A synthetic eddy method is proposed to properly model turbulence inlet velocity boundary conditions. This method will be compared with the standard pressure gradient forcing. WMLES are usually performed using a standard Smagorinsky model or its dynamic version. It is proposed here to investigate a subgrid scale (SGS) model with a better spectral behavior. To this end, a regularized variational multiscale (RVMs) model (Jeanmart and Winckelmans, 2007) is implemented together with standard wall function in order to preserve the dynamics of the large scales within the Ekman layer. The influence of the improved SGS model on the wind simulation and scalar transport will be discussed based on turbulence diagnostics.

42 CFR 419.2 - Basis of payment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... prospective payment system establishes a national payment rate, standardized for geographic wage differences... X-ray tests, diagnostic laboratory tests, and other diagnostic tests; (10) Durable medical equipment...

A high-throughput detection method for invasive fruit fly (Diptera: Tephritidae) species based on microfluidic dynamic array.

PubMed

Jiang, Fan; Fu, Wei; Clarke, Anthony R; Schutze, Mark Kurt; Susanto, Agus; Zhu, Shuifang; Li, Zhihong

2016-11-01

Invasive species can be detrimental to a nation's ecology, economy and human health. Rapid and accurate diagnostics are critical to limit the establishment and spread of exotic organisms. The increasing rate of biological invasions relative to the taxonomic expertise available generates a demand for high-throughput, DNA-based diagnostics methods for identification. We designed species-specific qPCR primer and probe combinations for 27 economically important tephritidae species in six genera (Anastrepha, Bactrocera, Carpomya, Ceratitis, Dacus and Rhagoletis) based on 935 COI DNA barcode haplotypes from 181 fruit fly species publically available in BOLD, and then tested the specificity for each primer pair and probe through qPCR of 35 of those species. We then developed a standardization reaction system for detecting the 27 target species based on a microfluidic dynamic array and also applied the method to identify unknown immature samples from port interceptions and field monitoring. This method led to a specific and simultaneous detection for all 27 species in 7.5 h, using only 0.2 μL of reaction system in each reaction chamber. The approach successfully discriminated among species within complexes that had genetic similarities of up to 98.48%, while it also identified all immature samples consistent with the subsequent results of morphological examination of adults which were reared from larvae of cohorts from the same samples. We present an accurate, rapid and high-throughput innovative approach for detecting fruit flies of quarantine concern. This is a new method which has broad potential to be one of international standards for plant quarantine and invasive species detection. © 2016 John Wiley & Sons Ltd.

Verification of examination procedures in clinical laboratory for imprecision, trueness and diagnostic accuracy according to ISO 15189:2012: a pragmatic approach.

PubMed

Antonelli, Giorgia; Padoan, Andrea; Aita, Ada; Sciacovelli, Laura; Plebani, Mario

2017-08-28

Background The International Standard ISO 15189 is recognized as a valuable guide in ensuring high quality clinical laboratory services and promoting the harmonization of accreditation programmes in laboratory medicine. Examination procedures must be verified in order to guarantee that their performance characteristics are congruent with the intended scope of the test. The aim of the present study was to propose a practice model for implementing procedures employed for the verification of validated examination procedures already used for at least 2 years in our laboratory, in agreement with the ISO 15189 requirement at the Section 5.5.1.2. Methods In order to identify the operative procedure to be used, approved documents were identified, together with the definition of performance characteristics to be evaluated for the different methods; the examination procedures used in laboratory were analyzed and checked for performance specifications reported by manufacturers. Then, operative flow charts were identified to compare the laboratory performance characteristics with those declared by manufacturers. Results The choice of performance characteristics for verification was based on approved documents used as guidance, and the specific purpose tests undertaken, a consideration being made of: imprecision and trueness for quantitative methods; diagnostic accuracy for qualitative methods; imprecision together with diagnostic accuracy for semi-quantitative methods. Conclusions The described approach, balancing technological possibilities, risks and costs and assuring the compliance of the fundamental component of result accuracy, appears promising as an easily applicable and flexible procedure helping laboratories to comply with the ISO 15189 requirements.

Antimicrobial susceptibility of Escherichia coli F4, Pasteurella multocida, and Streptococcus suis isolates from a diagnostic veterinary laboratory and recommendations for a surveillance system

PubMed Central

Glass-Kaastra, Shiona K.; Pearl, David L.; Reid-Smith, Richard J.; McEwen, Beverly; Slavic, Durda; McEwen, Scott A.; Fairles, Jim

2014-01-01

Antimicrobial susceptibility data on Escherichia coli F4, Pasteurella multocida, and Streptococcus suis isolates from Ontario swine (January 1998 to October 2010) were acquired from a comprehensive diagnostic veterinary laboratory in Ontario, Canada. In relation to the possible development of a surveillance system for antimicrobial resistance, data were assessed for ease of management, completeness, consistency, and applicability for temporal and spatial statistical analyses. Limited farm location data precluded spatial analyses and missing demographic data limited their use as predictors within multivariable statistical models. Changes in the standard panel of antimicrobials used for susceptibility testing reduced the number of antimicrobials available for temporal analyses. Data consistency and quality could improve over time in this and similar diagnostic laboratory settings by encouraging complete reporting with sample submission and by modifying database systems to limit free-text data entry. These changes could make more statistical methods available for disease surveillance and cluster detection. PMID:24688133

Antimicrobial susceptibility of Escherichia coli F4, Pasteurella multocida, and Streptococcus suis isolates from a diagnostic veterinary laboratory and recommendations for a surveillance system.

PubMed

Glass-Kaastra, Shiona K; Pearl, David L; Reid-Smith, Richard J; McEwen, Beverly; Slavic, Durda; McEwen, Scott A; Fairles, Jim

2014-04-01

Antimicrobial susceptibility data on Escherichia coli F4, Pasteurella multocida, and Streptococcus suis isolates from Ontario swine (January 1998 to October 2010) were acquired from a comprehensive diagnostic veterinary laboratory in Ontario, Canada. In relation to the possible development of a surveillance system for antimicrobial resistance, data were assessed for ease of management, completeness, consistency, and applicability for temporal and spatial statistical analyses. Limited farm location data precluded spatial analyses and missing demographic data limited their use as predictors within multivariable statistical models. Changes in the standard panel of antimicrobials used for susceptibility testing reduced the number of antimicrobials available for temporal analyses. Data consistency and quality could improve over time in this and similar diagnostic laboratory settings by encouraging complete reporting with sample submission and by modifying database systems to limit free-text data entry. These changes could make more statistical methods available for disease surveillance and cluster detection.

Noninvasive Brain Stimulation in Pediatric Attention-Deficit Hyperactivity Disorder (ADHD): A Review.

PubMed

Rubio, Belen; Boes, Aaron D; Laganiere, Simon; Rotenberg, Alexander; Jeurissen, Danique; Pascual-Leone, Alvaro

2016-05-01

Attention-deficit hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders in the pediatric population. The clinical management of ADHD is currently limited by a lack of reliable diagnostic biomarkers and inadequate therapy for a minority of patients who do not respond to standard pharmacotherapy. There is optimism that noninvasive brain stimulation may help to address these limitations. Transcranial magnetic stimulation and transcranial direct current stimulation are 2 methods of noninvasive brain stimulation that modulate cortical excitability and brain network activity. Transcranial magnetic stimulation can be used diagnostically to probe cortical neurophysiology, whereas daily use of repetitive transcranial magnetic stimulation or transcranial direct current stimulation can induce long-lasting and potentially therapeutic changes in targeted networks. In this review, we highlight research showing the potential diagnostic and therapeutic applications of transcranial magnetic stimulation and transcranial direct current stimulation in pediatric ADHD. We also discuss the safety and ethics of using these tools in the pediatric population. © The Author(s) 2015.

Current Perception Threshold for Assessment of the Neurological Components of Hand-Arm Vibration Syndrome: A Review

PubMed Central

Kurozawa, Youichi; Hosoda, Takenobu; Nasu, Yoshiro

2010-01-01

Current perception threshold (CPT) has been proposed as a quantitative method for assessment of peripheral sensory nerve function. The aim of this review of selected reports is to provide an overview of CPT measurement for the assessment of the neurological component of hand-arm vibration syndrome (HAVS). The CPT values at 2000 Hz significantly increased for patients with HAVS. This result supports the previous histological findings that demyelination is found predominantly in the peripheral nerves in the hands of men exposed to hand-arm vibration. Diagnostic sensitivity and specificity were high for severe cases of Stockholm sensorineural (SSN) stage 3 compared with non-exposed controls, but not high for mild cases of SSN stage 1 or 2 and for carpal tunnel syndrome associated with HAVS. However, there are only a few studies on the diagnostic validity of the CPT test for the neurological components of HAVS. Further research is needed and should include diagnostic validity and standardizing of measurement conditions such as skin temperature. PMID:24031119

Detection and Characterization of Viral Species/Subspecies Using Isothermal Recombinase Polymerase Amplification (RPA) Assays.

PubMed

Glais, Laurent; Jacquot, Emmanuel

2015-01-01

Numerous molecular-based detection protocols include an amplification step of the targeted nucleic acids. This step is important to reach the expected sensitive detection of pathogens in diagnostic procedures. Amplifications of nucleic acid sequences are generally performed, in the presence of appropriate primers, using thermocyclers. However, the time requested to amplify molecular targets and the cost of the thermocycler machines could impair the use of these methods in routine diagnostics. Recombinase polymerase amplification (RPA) technique allows rapid (short-term incubation of sample and primers in an enzymatic mixture) and simple (isothermal) amplification of molecular targets. RPA protocol requires only basic molecular steps such as extraction procedures and agarose gel electrophoresis. Thus, RPA can be considered as an interesting alternative to standard molecular-based diagnostic tools. In this paper, the complete procedures to set up an RPA assay, applied to detection of RNA (Potato virus Y, Potyvirus) and DNA (Wheat dwarf virus, Mastrevirus) viruses, are described. The proposed procedure allows developing species- or subspecies-specific detection assay.

A method for the development of disease-specific reference standards vocabularies from textual biomedical literature resources

PubMed Central

Wang, Liqin; Bray, Bruce E.; Shi, Jianlin; Fiol, Guilherme Del; Haug, Peter J.

2017-01-01

Objective Disease-specific vocabularies are fundamental to many knowledge-based intelligent systems and applications like text annotation, cohort selection, disease diagnostic modeling, and therapy recommendation. Reference standards are critical in the development and validation of automated methods for disease-specific vocabularies. The goal of the present study is to design and test a generalizable method for the development of vocabulary reference standards from expert-curated, disease-specific biomedical literature resources. Methods We formed disease-specific corpora from literature resources like textbooks, evidence-based synthesized online sources, clinical practice guidelines, and journal articles. Medical experts annotated and adjudicated disease-specific terms in four classes (i.e., causes or risk factors, signs or symptoms, diagnostic tests or results, and treatment). Annotations were mapped to UMLS concepts. We assessed source variation, the contribution of each source to build disease-specific vocabularies, the saturation of the vocabularies with respect to the number of used sources, and the generalizability of the method with different diseases. Results The study resulted in 2588 string-unique annotations for heart failure in four classes, and 193 and 425 respectively for pulmonary embolism and rheumatoid arthritis in treatment class. Approximately 80% of the annotations were mapped to UMLS concepts. The agreement among heart failure sources ranged between 0.28 and 0.46. The contribution of these sources to the final vocabulary ranged between 18% and 49%. With the sources explored, the heart failure vocabulary reached near saturation in all four classes with the inclusion of minimal six sources (or between four to seven sources if only counting terms occurred in two or more sources). It took fewer sources to reach near saturation for the other two diseases in terms of the treatment class. Conclusions We developed a method for the development of disease-specific reference vocabularies. Expert-curated biomedical literature resources are substantial for acquiring disease-specific medical knowledge. It is feasible to reach near saturation in a disease-specific vocabulary using a relatively small number of literature sources. PMID:26971304

Magnetic resonance elastography is as accurate as liver biopsy for liver fibrosis staging.

PubMed

Morisaka, Hiroyuki; Motosugi, Utaroh; Ichikawa, Shintaro; Nakazawa, Tadao; Kondo, Tetsuo; Funayama, Satoshi; Matsuda, Masanori; Ichikawa, Tomoaki; Onishi, Hiroshi

2018-05-01

Liver MR elastography (MRE) is available for the noninvasive assessment of liver fibrosis; however, no previous studies have compared the diagnostic ability of MRE with that of liver biopsy. To compare the diagnostic accuracy of liver fibrosis staging between MRE-based methods and liver biopsy using the resected liver specimens as the reference standard. A retrospective study at a single institution. In all, 200 patients who underwent preoperative MRE and subsequent surgical liver resection were included in this study. Data from 80 patients were used to estimate cutoff and distributions of liver stiffness values measured by MRE for each liver fibrosis stage (F0-F4, METAVIR system). In the remaining 120 patients, liver biopsy specimens were obtained from the resected liver tissues using a standard biopsy needle. 2D liver MRE with gradient-echo based sequence on a 1.5 or 3T scanner was used. Two radiologists independently measured the liver stiffness value on MRE and two types of MRE-based methods (threshold and Bayesian prediction method) were applied. Two pathologists evaluated all biopsy samples independently to stage liver fibrosis. Surgically resected whole tissue specimens were used as the reference standard. The accuracy for liver fibrosis staging was compared between liver biopsy and MRE-based methods with a modified McNemar's test. Accurate fibrosis staging was achieved in 53.3% (64/120) and 59.1% (71/120) of patients using MRE with threshold and Bayesian methods, respectively, and in 51.6% (62/120) with liver biopsy. Accuracies of MRE-based methods for diagnoses of ≥F2 (90-91% [108-9/120]), ≥F3 (79-81% [95-97/120]), and F4 (82-85% [98-102/120]) were statistically equivalent to those of liver biopsy (≥F2, 79% [95/120], P ≤ 0.01; ≥F3, 88% [105/120], P ≤ 0.006; and F4, 82% [99/120], P ≤ 0.017). MRE can be an alternative to liver biopsy for fibrosis staging. 3. Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1268-1275. © 2017 International Society for Magnetic Resonance in Medicine.

20 CFR 404.1519m - Diagnostic tests or procedures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Standards for the Type of Referral and for Report Content § 404.1519m Diagnostic tests or procedures. We will request the results of any diagnostic..., arteriograms, or cardiac catheterizations for the evaluation of disability under the Social Security program. A...

Recombinase polymerase amplification combined with a lateral flow dipstick for rapid and visual detection of Schistosoma japonicum.

PubMed

Sun, Kui; Xing, Weiwei; Yu, Xinling; Fu, Wenliang; Wang, Yuanyuan; Zou, Minji; Luo, Zhihong; Xu, Donggang

2016-08-31

With the continuous decline in prevalence and intensity of Schistosoma japonicum infection in China, more accurate and sensitive methods suitable for field detection become much needed for schistosomiasis control. Here, a novel rapid and visual detection method based on the combination of recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) was developed to detect S. japonicum DNA in fecal samples. The LFD-RPA assay targeting SjR2 could detect 5 fg S. japonicum DNA, which was identical to qPCR and real-time RPA assay, and showed no cross-reaction with other parasites. The detection could be finished within 15-20 min at a wide temperature range (25-45 °C), and the results could be visualized by naked eye. The diagnostic validity of LFD-RPA assay was further assessed with 14 fecal samples of infected patients diagnosed by Kato-Katz method and 31 fecal samples of healthy persons, and compared with that of Enzyme-linked immunosorbent assay (ELSIA) and Indirect Hemagglutination Assay (IHA). The LFD-RPA assay showed 92.68 % sensitivity, 100 % specificity and excellent diagnostic agreement with the gold standard Kato-Katz test (k = 0.947, Z = 6.36, P < 0.001), whereas ELISA showed 85.71 % sensitivity, 93.55 % specificity, and substantial diagnostic agreement (k = 0.793, Z = 5.31, P < 0.001), and IHA showed 78.57 % sensitivity, 83.87 % specificity, and moderate diagnostic agreement (k = 0.600, Z = 4.05, P < 0.001), indicating that the LFD-RPA was much better than the traditional methods. The LFD-RPA assay established by us is a sensitive, specific, rapid and convenient method for the diagnosis of schistosomiasis, and shows a great potency in field application.

Evaluation of the Revised Algorithm of Autism Diagnostic Observation Schedule (ADOS) in the Diagnostic Investigation of High-Functioning Children and Adolescents with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Kamp-Becker, Inge; Ghahreman, Mardjan; Heinzel-Gutenbrunner, Monika; Peters, Mira; Remschmidt, Helmut; Becker, Katja

2013-01-01

The Autism Diagnostic Observation Schedule (ADOS) is a semi-structured, standardized assessment designed for use in diagnostic evaluation of individuals with suspected autism spectrum disorder (ASD). The ADOS has been effective in categorizing children who definitely have autism or not, but has lower specificity and sometimes sensitivity for…

Issues in using whole slide imaging for diagnostic pathology: "routine" stains, immunohistochemistry and predictive markers.

PubMed

Taylor, C R

2014-08-01

The traditional microscope, together with the "routine" hematoxylin and eosin (H & E) stain, remains the "gold standard" for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of "stains" available. Because of the need for specific identification and even measurement of "biomarkers," immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides.

Neuroimaging-based biomarkers in psychiatry: clinical opportunities of a paradigm shift.

PubMed

Fu, Cynthia H Y; Costafreda, Sergi G

2013-09-01

Neuroimaging research has substantiated the functional and structural abnormalities underlying psychiatric disorders but has, thus far, failed to have a significant impact on clinical practice. Recently, neuroimaging-based diagnoses and clinical predictions derived from machine learning analysis have shown significant potential for clinical translation. This review introduces the key concepts of this approach, including how the multivariate integration of patterns of brain abnormalities is a crucial component. We survey recent findings that have potential application for diagnosis, in particular early and differential diagnoses in Alzheimer disease and schizophrenia, and the prediction of clinical response to treatment in depression. We discuss the specific clinical opportunities and the challenges for developing biomarkers for psychiatry in the absence of a diagnostic gold standard. We propose that longitudinal outcomes, such as early diagnosis and prediction of treatment response, offer definite opportunities for progress. We propose that efforts should be directed toward clinically challenging predictions in which neuroimaging may have added value, compared with the existing standard assessment. We conclude that diagnostic and prognostic biomarkers will be developed through the joint application of expert psychiatric knowledge in addition to advanced methods of analysis.

Circulating microRNA Biomarkers as Liquid Biopsy for Cancer Patients: Pros and Cons of Current Assays

PubMed Central

Ono, Shigeshi; Lam, Stella; Nagahara, Makoto; Hoon, Dave S. B.

2015-01-01

An increasing number of studies have focused on circulating microRNAs (cmiRNA) in cancer patients’ blood for their potential as minimally-invasive biomarkers. Studies have reported the utility of assessing specific miRNAs in blood as diagnostic/prognostic biomarkers; however, the methodologies are not validated or standardized across laboratories. Unfortunately, there is often minimum limited overlap in techniques between results reported even in similar type studies on the same cancer. This hampers interpretation and reliability of cmiRNA as potential cancer biomarkers. Blood collection and processing, cmiRNA extractions, quality and quantity control of assays, defined patient population assessment, reproducibility, and reference standards all affect the cmiRNA assay results. To date, there is no reported definitive method to assess cmiRNAs. Therefore, appropriate and reliable methodologies are highly necessary in order for cmiRNAs to be used in regulated clinical diagnostic laboratories. In this review, we summarize the developments made over the past decade towards cmiRNA detection and discuss the pros and cons of the assays. PMID:26512704

The challenge of Propionibacterium acnes and revision shoulder arthroplasty: a review of current diagnostic options.

PubMed

Shields, Margaret V; Abdullah, Leath; Namdari, Surena

2016-06-01

Propionibacterium acnes is the most common cause of infection after shoulder arthroplasty. Whereas there are several methods that can aid in the diagnosis of P. acnes infection, there is not a single "gold standard" because of the difficulties inherent in identifying this bacterium. We present an evidence-based discussion of the demographic, clinical, and radiographic predictors of P. acnes infection and review the current options for diagnosis. This review was written after a comprehensive analysis of the current literature related to shoulder periprosthetic joint infection and P. acnes identification. Of the techniques reviewed, α-defensin had the highest sensitivity in detecting P. acnes infection (63%). C-reactive protein level and erythrocyte sedimentation rate were often normal in cases of infection. Whereas P. acnes can be challenging to successfully diagnose, there are several options that are considered preferable because of their higher sensitivities and specificities. The current gold standard is intraoperative culture, but major advances in molecular techniques may provide future improvements in diagnostic accuracy. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Towards Dynamic Contrast Specific Ultrasound Tomography

NASA Astrophysics Data System (ADS)

Demi, Libertario; van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-10-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography.

PubMed

Demi, Libertario; Van Sloun, Ruud J G; Wijkstra, Hessel; Mischi, Massimo

2016-10-05

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast.

Towards Dynamic Contrast Specific Ultrasound Tomography

PubMed Central

Demi, Libertario; Van Sloun, Ruud J. G.; Wijkstra, Hessel; Mischi, Massimo

2016-01-01

We report on the first study demonstrating the ability of a recently-developed, contrast-enhanced, ultrasound imaging method, referred to as cumulative phase delay imaging (CPDI), to image and quantify ultrasound contrast agent (UCA) kinetics. Unlike standard ultrasound tomography, which exploits changes in speed of sound and attenuation, CPDI is based on a marker specific to UCAs, thus enabling dynamic contrast-specific ultrasound tomography (DCS-UST). For breast imaging, DCS-UST will lead to a more practical, faster, and less operator-dependent imaging procedure compared to standard echo-contrast, while preserving accurate imaging of contrast kinetics. Moreover, a linear relation between CPD values and ultrasound second-harmonic intensity was measured (coefficient of determination = 0.87). DCS-UST can find clinical applications as a diagnostic method for breast cancer localization, adding important features to multi-parametric ultrasound tomography of the breast. PMID:27703251

A Novel Method for Pulsometry Based on Traditional Iranian Medicine

PubMed Central

Yousefipoor, Farzane; Nafisi, Vahidreza

2015-01-01

Arterial pulse measurement is one of the most important methods for evaluation of healthy conditions. In traditional Iranian medicine (TIM), physician may detect radial pulse by holding four fingers on the patient's wrist. By using this method, under standard condition, the detected pulses are subjective and erroneous, in case of weak and/or abnormal pulses, the ambiguity of diagnosis may rise. In this paper, we present an equipment which is designed and implemented for automation of traditional pulse detection method. By this novel system, the developed noninvasive diagnostic method and database based on the TIM are way forward to apply traditional medicine and diagnose patients with present technology. The accuracy for period measuring is 76% and systolic peak is 72%. PMID:26955566

Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections.

PubMed

Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I; Zumla, Alimuddin; Barry, Thomas

2015-09-01

Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Comparison of Established Diagnostic Methodologies and a Novel Bacterial smpB Real-Time PCR Assay for Specific Detection of Haemophilus influenzae Isolates Associated with Respiratory Tract Infections

PubMed Central

Reddington, Kate; Schwenk, Stefan; Tuite, Nina; Platt, Gareth; Davar, Danesh; Coughlan, Helena; Personne, Yoann; Gant, Vanya; Enne, Virve I.; Zumla, Alimuddin

2015-01-01

Haemophilus influenzae is a significant causative agent of respiratory tract infections (RTI) worldwide. The development of a rapid H. influenzae diagnostic assay that would allow for the implementation of infection control measures and also improve antimicrobial stewardship for patients is required. A number of nucleic acid diagnostics approaches that detect H. influenzae in RTIs have been described in the literature; however, there are reported specificity and sensitivity limitations for these assays. In this study, a novel real-time PCR diagnostic assay targeting the smpB gene was designed to detect all serogroups of H. influenzae. The assay was validated using a panel of well-characterized Haemophilus spp. Subsequently, 44 Haemophilus clinical isolates were collected, and 36 isolates were identified as H. influenzae using a gold standard methodology that combined the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and a fucK diagnostic assay. Using the novel smpB diagnostic assay, 100% concordance was observed with the gold standard, demonstrating a sensitivity of 100% (95% confidence interval [CI], 90.26% to 100.00%) and a specificity of 100% (95% CI, 63.06% to 100.00%) when used on clinical isolates. To demonstrate the clinical utility of the diagnostic assay presented, a panel of lower RTI samples (n = 98) were blindly tested with the gold standard and smpB diagnostic assays. The results generated were concordant for 94/98 samples tested, demonstrating a sensitivity of 90.91% (95% CI, 78.33% to 97.47%) and a specificity of 100% (95% CI, 93.40% to 100.00%) for the novel smpB assay when used directly on respiratory specimens. PMID:26109443

Atlanto-occipital dislocation--part 2: The clinical use of (occipital) condyle-C1 interval, comparison with other diagnostic methods, and the manifestation, management, and outcome of atlanto-occipital dislocation in children.

PubMed

Pang, Dachling; Nemzek, William R; Zovickian, John

2007-11-01

The diagnosis of atlanto-occipital dislocation (AOD) remains problematic as a result of a lack of reliable radiodiagnostic criteria. In Part 1 of the AOD series, we showed that the normal occiput-C1 joint in children has an extremely narrow joint gap (condyle-C1 interval [CCI]) with great left-right symmetry. In Part 2, we used a CCI of 4 mm or greater measured on reformatted computed tomographic (CT) scans as the indicator for AOD and tested the diagnostic sensitivity and specificity of CCI against published criteria. The clinical manifestation, neuroimaging findings, management, and outcome of our series of patients with AOD are also reported. For diagnostic sensitivity, we applied the CCI criterion on 16 patients who fulfilled one or more accepted radiodiagnostic criteria of AOD and who showed clinical and imaging hallmarks of the syndrome. All 16 patients had plain cervical spine x-rays, head CT scans, axial cervical spine CT scans with reconstruction, and magnetic resonance imaging scans. The diagnostic yield and false-negative rate of CCI were compared with those of four published "standard" tests, namely Wholey's dens-basion interval, Powers' ratio, Harris' basion-axis interval, and Sun's interspinous ratio. The diagnostic value of "nonstandard" indicators such as cervicomedullary deficits, tectorial membrane and other ligamentous damage, perimedullary subarachnoid hemorrhage, and extra-axial blood at C1-C2 were also assessed. For diagnostic specificity, we applied CCI and the "standard" and "nonstandard" tests on 10 patients from five classes of non-AOD upper cervical injuries. The false-positive diagnostic rates for AOD of all respective tests were documented. The CCI criterion was positive in all 16 patients with AOD with a diagnostic sensitivity of 100%. Fourteen patients had bilateral AOD with disruption and widening of both OC1 joints. Two patients had unilateral AOD with only one joint wider than 4 mm. The abnormal CCI varied from 5 to 34 mm. Eight patients showed blatant left-right joint asymmetry in either CCI or anatomic conformation. The diagnostic sensitivities for the "standard" tests are as follows: Wholey's, 50%; Powers', 37.5%; Harris', 31%; and Sun's, 25%, with false-negative rates of 50, 62.5, 69, and 75%, respectively. The sensitivities for the "nonstandard" indicators are: tectorial membrane damage, 71%; perimedullary blood, 63%; and C1-C2 extra-axial blood, 75%, with false-negative rates of 29, 37, and 25%, respectively. Fifteen patients with AOD had occiput-cervical fusion. There were one early and two delayed deaths (19% mortality); two patients (12%) had complete or severe residual high quadriplegia, but 11 children (69%) enjoyed excellent neurological recovery. CCI was normal in all 10 patients with non-AOD upper cervical injuries with a diagnostic specificity of 100%. The false-positive rates for the four "standard" tests were: Sun's, 60%; Harris', 50%; Wholey's, 30%; and Powers', 10%; for the "nonstandard" indicator, the rates were: cervicomedullary deficits, 70%; tectorial membrane damage, 40%; C1-C2 extra-axial blood, 40%; and perimedullary blood, 30%. The CCI criterion has the highest diagnostic sensitivity and specificity for AOD among all other radiodiagnostic criteria and indicators. CCI is easily computed from reconstructed CT scans, has almost no logistical or technical distortions, can capture occiput-C1 joint dislocation in all three planes, and is unaffected by congenital anomalies or maturation changes of adjacent structures. Because CCI is the only test that directly measures the integrity of the actual joint injured in AOD and a widened CCI cannot be concealed by postinjury changes in the head and neck relationship, it surpasses others that use changeable landmarks.

PROPELLER technique to improve image quality of MRI of the shoulder.

PubMed

Dietrich, Tobias J; Ulbrich, Erika J; Zanetti, Marco; Fucentese, Sandro F; Pfirrmann, Christian W A

2011-12-01

The purpose of this article is to evaluate the use of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for artifact reduction and overall image quality improvement for intermediate-weighted and T2-weighted MRI of the shoulder. One hundred eleven patients undergoing MR arthrography of the shoulder were included. A coronal oblique intermediate-weighted turbo spin-echo (TSE) sequence with fat suppression and a sagittal oblique T2-weighted TSE sequence with fat suppression were obtained without (standard) and with the PROPELLER technique. Scanning time increased from 3 minutes 17 seconds to 4 minutes 17 seconds (coronal oblique plane) and from 2 minutes 52 seconds to 4 minutes 10 seconds (sagittal oblique) using PROPELLER. Two radiologists graded image artifacts, overall image quality, and delineation of several anatomic structures on a 5-point scale (5, no artifact, optimal diagnostic quality; and 1, severe artifacts, diagnostically not usable). The Wilcoxon signed rank test was used to compare the data of the standard and PROPELLER images. Motion artifacts were significantly reduced in PROPELLER images (p < 0.001). Observer 1 rated motion artifacts with diagnostic impairment in one patient on coronal oblique PROPELLER images compared with 33 patients on standard images. Ratings for the sequences with PROPELLER were significantly better for overall image quality (p < 0.001). Observer 1 noted an overall image quality with diagnostic impairment in nine patients on sagittal oblique PROPELLER images compared with 23 patients on standard MRI. The PROPELLER technique for MRI of the shoulder reduces the number of sequences with diagnostic impairment as a result of motion artifacts and increases image quality compared with standard TSE sequences. PROPELLER sequences increase the acquisition time.

Performance Evaluation of an Automated ELISA System for Alzheimer's Disease Detection in Clinical Routine.

PubMed

Chiasserini, Davide; Biscetti, Leonardo; Farotti, Lucia; Eusebi, Paolo; Salvadori, Nicola; Lisetti, Viviana; Baschieri, Francesca; Chipi, Elena; Frattini, Giulia; Stoops, Erik; Vanderstichele, Hugo; Calabresi, Paolo; Parnetti, Lucilla

2016-07-22

The variability of Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers undermines their full-fledged introduction into routine diagnostics and clinical trials. Automation may help to increase precision and decrease operator errors, eventually improving the diagnostic performance. Here we evaluated three new CSF immunoassays, EUROIMMUNtrademark amyloid-β 1-40 (Aβ1-40), amyloid-β 1-42 (Aβ1-42), and total tau (t-tau), in combination with automated analysis of the samples. The CSF biomarkers were measured in a cohort consisting of AD patients (n = 28), mild cognitive impairment (MCI, n = 77), and neurological controls (OND, n = 35). MCI patients were evaluated yearly and cognitive functions were assessed by Mini-Mental State Examination. The patients clinically diagnosed with AD and MCI were classified according to the CSF biomarkers profile following NIA-AA criteria and the Erlangen score. Technical evaluation of the immunoassays was performed together with the calculation of their diagnostic performance. Furthermore, the results for EUROIMMUN Aβ1-42 and t-tau were compared to standard immunoassay methods (INNOTESTtrademark). EUROIMMUN assays for Aβ1-42 and t-tau correlated with INNOTEST (r = 0.83, p < 0.001 for both) and allowed a similar interpretation of the CSF profiles. The Aβ1-42/Aβ1-40 ratio measured with EUROIMMUN was the best parameter for AD detection and improved the diagnostic accuracy of Aβ1-42 (area under the curve = 0.93). In MCI patients, the Aβ1-42/Aβ1-40 ratio was associated with cognitive decline and clinical progression to AD.The diagnostic performance of the EUROIMMUN assays with automation is comparable to other currently used methods. The variability of the method and the value of the Aβ1-42/Aβ1-40 ratio in AD diagnosis need to be validated in large multi-center studies.

Economic evaluation of diagnostic methods used in dentistry. A systematic review.

PubMed

Christell, Helena; Birch, Stephen; Horner, Keith; Lindh, Christina; Rohlin, Madeleine

2014-11-01

To review the literature of economic evaluations regarding diagnostic methods used in dentistry. Four databases (MEDLINE, Web of Science, The Cochrane library, the NHS Economic Evaluation Database) were searched for studies, complemented by hand search, until February 2013. Two authors independently screened all titles or abstracts and then applied inclusion and exclusion criteria to select full-text publications published in English, which reported an economic evaluation comparing at least two alternative methods. Studies of diagnostic methods were assessed by four reviewers using a protocol based on the QUADAS tool regarding diagnostic methods and a check-list for economic evaluations. The results of the data extraction were summarized in a structured table and as a narrative description. From 476 identified full-text publications, 160 were considered to be economic evaluations. Only 12 studies (7%) were on diagnostic methods, whilst 78 studies (49%) were on prevention and 70 (40%) on treatment. Among studies on diagnostic methods, there was between-study heterogeneity methodologically, regarding the diagnostic method analysed and type of economic evaluation addressed. Generally, the choice of economic evaluation method was not justified and the perspective of the study not stated. Costing of diagnostic methods varied. A small body of literature addresses economic evaluation of diagnostic methods in dentistry. Thus, there is a need for studies from various perspectives with well defined research questions and measures of the cost and effectiveness. Economic resources in healthcare are finite. For diagnostic methods, an understanding of efficacy provides only part of the information needed for evidence-based practice. This study highlighted a paucity of economic evaluations of diagnostic methods used in dentistry, indicating that much of what we practise lacks sufficient evidence.

Development of an integrated Sasang constitution diagnosis method using face, body shape, voice, and questionnaire information.

PubMed

Do, Jun-Hyeong; Jang, Eunsu; Ku, Boncho; Jang, Jun-Su; Kim, Honggie; Kim, Jong Yeol

2012-07-04

Sasang constitutional medicine (SCM) is a unique form of traditional Korean medicine that divides human beings into four constitutional types (Tae-Yang: TY, Tae-Eum: TE, So-Yang: SY, and So-Eum: SE), which differ in inherited characteristics, such as external appearance, personality traits, susceptibility to particular diseases, drug responses, and equilibrium among internal organ functions. According to SCM, herbs that belong to a certain constitution cannot be used in patients with other constitutions; otherwise, this practice may result in no effect or in an adverse effect. Thus, the diagnosis of SC type is the most crucial step in SCM practice. The diagnosis, however, tends to be subjective due to a lack of quantitative standards for SC diagnosis. We have attempted to make the diagnosis method as objective as possible by basing it on an analysis of quantitative data from various Oriental medical clinics. Four individual diagnostic models were developed with multinomial logistic regression based on face, body shape, voice, and questionnaire responses. Inspired by SCM practitioners' holistic diagnostic processes, an integrated diagnostic model was then proposed by combining the four individual models. The diagnostic accuracies in the test set, after the four individual models had been integrated into a single model, improved to 64.0% and 55.2% in the male and female patient groups, respectively. Using a cut-off value for the integrated SC score, such as 1.6, the accuracies increased by 14.7% in male patients and by 4.6% in female patients, which showed that a higher integrated SC score corresponded to a higher diagnostic accuracy. This study represents the first trial of integrating the objectification of SC diagnosis based on quantitative data and SCM practitioners' holistic diagnostic processes. Although the diagnostic accuracy was not great, it is noted that the proposed diagnostic model represents common rules among practitioners who have various points of view. Our results are expected to contribute as a desirable research guide for objective diagnosis in traditional medicine, as well as to contribute to the precise diagnosis of SC types in an objective manner in clinical practice.

Proposal of a punch biopsy protocol as a pre-requisite for the establishment of a tissue bank from resected esophageal tumors.

PubMed

Bonavina, Luigi; Laface, Letizia; Picozzi, Stefano; Nencioni, Marco; Siboni, Stefano; Bona, Davide; Sironi, Andrea; Sorba, Francesca; Clemente, Claudio

2010-09-01

With the development of tissue banking, a need for homogeneous methods of collection, processing, and storage of tissue has emerged. We describe the implementation of a biological bank in a high-volume, tertiary care University referral center for esophageal cancer surgery. We also propose an original punch biopsy technique of the surgical specimen. The method proved to be simple, reproducible, and not expensive. Unified standards for specimen collection are necessary to improve results of specimen-based diagnostic testing and research in surgical oncology.

Selection and Reporting of Statistical Methods to Assess Reliability of a Diagnostic Test: Conformity to Recommended Methods in a Peer-Reviewed Journal

PubMed Central

Park, Ji Eun; Han, Kyunghwa; Sung, Yu Sub; Chung, Mi Sun; Koo, Hyun Jung; Yoon, Hee Mang; Choi, Young Jun; Lee, Seung Soo; Kim, Kyung Won; Shin, Youngbin; An, Suah; Cho, Hyo-Min

2017-01-01

Objective To evaluate the frequency and adequacy of statistical analyses in a general radiology journal when reporting a reliability analysis for a diagnostic test. Materials and Methods Sixty-three studies of diagnostic test accuracy (DTA) and 36 studies reporting reliability analyses published in the Korean Journal of Radiology between 2012 and 2016 were analyzed. Studies were judged using the methodological guidelines of the Radiological Society of North America-Quantitative Imaging Biomarkers Alliance (RSNA-QIBA), and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative. DTA studies were evaluated by nine editorial board members of the journal. Reliability studies were evaluated by study reviewers experienced with reliability analysis. Results Thirty-one (49.2%) of the 63 DTA studies did not include a reliability analysis when deemed necessary. Among the 36 reliability studies, proper statistical methods were used in all (5/5) studies dealing with dichotomous/nominal data, 46.7% (7/15) of studies dealing with ordinal data, and 95.2% (20/21) of studies dealing with continuous data. Statistical methods were described in sufficient detail regarding weighted kappa in 28.6% (2/7) of studies and regarding the model and assumptions of intraclass correlation coefficient in 35.3% (6/17) and 29.4% (5/17) of studies, respectively. Reliability parameters were used as if they were agreement parameters in 23.1% (3/13) of studies. Reproducibility and repeatability were used incorrectly in 20% (3/15) of studies. Conclusion Greater attention to the importance of reporting reliability, thorough description of the related statistical methods, efforts not to neglect agreement parameters, and better use of relevant terminology is necessary. PMID:29089821

A new framework for the documentation and interpretation of oral food challenges in population-based and clinical research.

PubMed

Grabenhenrich, L B; Reich, A; Bellach, J; Trendelenburg, V; Sprikkelman, A B; Roberts, G; Grimshaw, K E C; Sigurdardottir, S; Kowalski, M L; Papadopoulos, N G; Quirce, S; Dubakiene, R; Niggemann, B; Fernández-Rivas, M; Ballmer-Weber, B; van Ree, R; Schnadt, S; Mills, E N C; Keil, T; Beyer, K

2017-03-01

The conduct of oral food challenges as the preferred diagnostic standard for food allergy (FA) was harmonized over the last years. However, documentation and interpretation of challenge results, particularly in research settings, are not sufficiently standardized to allow valid comparisons between studies. Our aim was to develop a diagnostic toolbox to capture and report clinical observations in double-blind placebo-controlled food challenges (DBPCFC). A group of experienced allergists, paediatricians, dieticians, epidemiologists and data managers developed generic case report forms and standard operating procedures for DBPCFCs and piloted them in three clinical centres. The follow-up of the EuroPrevall/iFAAM birth cohort and other iFAAM work packages applied these methods. A set of newly developed questionnaire or interview items capture the history of FA. Together with sensitization status, this forms the basis for the decision to perform a DBPCFC, following a standardized decision algorithm. A generic form including details about severity and timing captures signs and symptoms observed during or after the procedures. In contrast to the commonly used dichotomous outcome FA vs no FA, the allergy status is interpreted in multiple categories to reflect the complexity of clinical decision-making. The proposed toolbox sets a standard for improved documentation and harmonized interpretation of DBPCFCs. By a detailed documentation and common terminology for communicating outcomes, these tools hope to reduce the influence of subjective judgment of supervising physicians. All forms are publicly available for further evolution and free use in clinical and research settings. © 2016 The Authors. Allergy Published by John Wiley & Sons Ltd.

[Polish version of the ADOS (autism diagnostic observation schedule-generic)].

PubMed

Chojnicka, Izabela; Płoski, Rafał

2012-01-01

The article presents the Polish version of the autism diagnostic observation schedule-generic (ADOS), which together with the autism diagnostic interview-revised (ADI-R) is cited as the "gold standard" for the diagnosis of autism. The ADOS is a standardised, semistructured observation protocol appropriate for children and adults of differing age and language levels. It is linked to ICD-10 and DSM-IV-TR criteria. The ADOS consists of four modules, ranging from module 1 for nonverbal individuals to module 4 for verbally fluent adults. The adequate inter-rater reliability for items has been established. The protocol has high discriminant validity and distinguishes children with pervasive developmental disorders from children, who are outside of the spectrum. Although it does not enable to distinguish individuals with pervasive developmental disorder, unspecified from individuals with childhood autism. The paper presents subsequent steps of the translation process of the original version into Polish, as well as a chosen adaptation strategy of the Polish version. The ADOS is a very useful tool both for clinical diagnosis and for the scientific purpose diagnosis. In this last case it is extremely important to use a standardised method. Until now, there was no standardised diagnostic tool for autism in Poland.

Thoracic radiography in the cat: Identification of cardiomegaly and congestive heart failure.

PubMed

Guglielmini, Carlo; Diana, Alessia

2015-12-01

Thoracic radiography is one of the most commonly employed diagnostic tools for the clinical evaluation of cats with suspected heart disease and is the standard diagnostic method in the confirmation of cardiogenic pulmonary edema. In the past, interpretation of feline radiographs focused on a description of the qualitative radiographic features of feline heart disease or the measurement of the cardiac silhouette in healthy cats and cats with different cardiovascular disorders. More recently, studies have begun to critically address the issue of the diagnostic accuracy of thoracic radiography in the diagnostic work-up of cats with heart disease. In these studies, qualitative and quantitative radiographic parameters were compared to echocardiographic findings to evaluate the usefulness of thoracic radiography for the identification of cardiac enlargement and pulmonary edema in the cat. Thoracic radiography is reasonably specific but has a low sensitivity when identifying cardiomegaly in cats with mild structural heart disease. Feline cardiogenic pulmonary edema has a variable radiographic presentation and several specific radiographic findings (i.e., enlargement of the left atrium and the pulmonary veins) can be absent or non-recognizable in affected cats. Copyright © 2015 Elsevier B.V. All rights reserved.

The comparative accuracy of rapid diagnostic test with microscopy to diagnose malaria in subdistrict lima puluh batubara regency North Sumatera province

NASA Astrophysics Data System (ADS)

Rezeki, S.; Pasaribu, A. P.

2018-03-01

Indonesia is the country where malaria is still the most common population problem. The high rate of mortality and morbidity occurred due to delays in diagnosis whichis strongly influenced by the availability of diagnostic tools and personnel with required laboratory skill. This diagnostic study aims to compare the accuracy of a Rapid Diagnostic Test (RDT) without skill requirement, to agold standard microscopic method for malaria diagnosis. The study was conducted in Subdistrict Lima Puluh North Sumatera Province from December 2015 to January 2016. The subject was taken cross-sectionally from a population with characteristics typically found in malaria patients in Subdistrict Lima Puluh. The result showed a sensitivity of 100% and a specificity of 72.4% with a positive predictive value of 89.9% and a negative predictive value of 100%; the negative likelihood ratio is 0 and the positive likelihood ratio of 27.6 for Parascreen. This research indicates that Parascreen had a high sensitivity and specificity and may be consideredas an alternative for the diagnosis of malaria in Subdistrict Lima Puluh North Sumatera Province especially in areas where no skilled microscopist is available.

Fourier transform infrared evanescent wave (FTIR-FEW) spectroscopy of tissue

NASA Astrophysics Data System (ADS)

Bruch, Reinhard F.; Sukuta, Sydney; Afanasyeva, Natalia I.; Kolyakov, Sergei F.; Butvina, Leonid N.

1997-05-01

A new Fourier transform infrared fiberoptic evanescent wave (FTIR-FEW) spectroscopy method has been developed for tissue diagnostics in the middle infrared (MIR) wavelength range (3 to 20 micrometers). Specific novel fiberoptical chemical and biological sensors have been studied and used for spectroscopic diagnostic purposes. These nontoxic and nonhygroscopic fiber sensors are characterized by (1) low optical losses (0.05 to 0.2 dB/m at about 10 micrometer) and (2) high flexibility. Our new fiber optical devices can be utilized with standard commercially available Fourier transform spectrometers including attenuated total reflection (ATR) techniques. They are in particular ideally suited for noninvasive, fast, direct, sensitive investigations of in vivo and ex vivo medical diagnostics applications. Here we present data on IR spectra of skin tissue in vivo for various cases of melanoma and nevus in the range of 1480 - 1800 cm-1. The interpretation of the spectra of healthy and different stages of tumor and cancer skin tissue clearly indicates that this technique can be used for precancer and cancer diagnostics. This technique can be designed for real-time and on-line computer modeling and analysis of tissue changes.

[Severity classification of chronic obstructive pulmonary disease based on deep learning].

PubMed

Ying, Jun; Yang, Ceyuan; Li, Quanzheng; Xue, Wanguo; Li, Tanshi; Cao, Wenzhe

2017-12-01

In this paper, a deep learning method has been raised to build an automatic classification algorithm of severity of chronic obstructive pulmonary disease. Large sample clinical data as input feature were analyzed for their weights in classification. Through feature selection, model training, parameter optimization and model testing, a classification prediction model based on deep belief network was built to predict severity classification criteria raised by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). We get accuracy over 90% in prediction for two different standardized versions of severity criteria raised in 2007 and 2011 respectively. Moreover, we also got the contribution ranking of different input features through analyzing the model coefficient matrix and confirmed that there was a certain degree of agreement between the more contributive input features and the clinical diagnostic knowledge. The validity of the deep belief network model was proved by this result. This study provides an effective solution for the application of deep learning method in automatic diagnostic decision making.

Quantum Cascade Laser-Based Infrared Microscopy for Label-Free and Automated Cancer Classification in Tissue Sections.

PubMed

Kuepper, Claus; Kallenbach-Thieltges, Angela; Juette, Hendrik; Tannapfel, Andrea; Großerueschkamp, Frederik; Gerwert, Klaus

2018-05-16

A feasibility study using a quantum cascade laser-based infrared microscope for the rapid and label-free classification of colorectal cancer tissues is presented. Infrared imaging is a reliable, robust, automated, and operator-independent tissue classification method that has been used for differential classification of tissue thin sections identifying tumorous regions. However, long acquisition time by the so far used FT-IR-based microscopes hampered the clinical translation of this technique. Here, the used quantum cascade laser-based microscope provides now infrared images for precise tissue classification within few minutes. We analyzed 110 patients with UICC-Stage II and III colorectal cancer, showing 96% sensitivity and 100% specificity of this label-free method as compared to histopathology, the gold standard in routine clinical diagnostics. The main hurdle for the clinical translation of IR-Imaging is overcome now by the short acquisition time for high quality diagnostic images, which is in the same time range as frozen sections by pathologists.