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Diagnostic Algorithms (diagnostic + algorithms)
Selected AbstractsTemporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagusLASERS IN SURGERY AND MEDICINE, Issue 1 2003T. Joshua Pfefer PhD Abstract Background and Objectives Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE). Study Design/Materials and Methods Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550,±,20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD. Results LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se,=,74%, Sp,=,67%) and 400 nm (Se,=,74%, Sp,=,85%) excitation. Conclusions In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes,possibly through modification of system parameters,is needed to improve accuracy levels. Lasers Surg. Med. 32:10,16,2003. © 2003 Wiley-Liss, Inc. [source] The impact of cytomorphology, cytogenetics, molecular genetics, and immunophenotyping in a comprehensive diagnostic workup of myelodysplastic syndromesCANCER, Issue 19 2009Ulrike Bacher MD Abstract BACKGROUND: Because of limited reproducibility of morphologic features, the morphological categorization of initial myelodysplastic syndromes (MDS) cases remains a major task in a diagnostic setting. METHODS: To further evaluate the role of additional diagnostic methods for suspected early MDS, the authors analyzed 1965 cases with unclear cytopenia where at least cytomorphology and immunophenotyping were performed in parallel, combined with cytogenetics and molecular genetics. RESULTS: In 353 patients, both methods diagnosed malignant/nonmalignant disease other than MDS, and 557 patients had MDS-refractory anemia with excess of blasts/chronic myelomonocytic leukemia. The remaining 1055 patients (53.7%), where early MDS/reactive cytopenia had to be assumed, were categorized into 6 groups depending on cytomorphology/immunophenotyping results for or against MDS. In 659 of 1055 cases (62.4%) with suspected initial MDS, cytomorphology and immunophenotyping were concordant in the categorization of MDS/non-MDS. Cytogenetics, available in 951 of 1055 patients, revealed the highest frequency of aberrant karyotypes when both cytomorphology and immunophenotyping proposed MDS (63 of 227; 27.8%). But also in the groups where either cytomorphology or immunophenotyping showed evidence of MDS, aberrant karyotypes were found in 6% to 14% of patients. Even when both morphology and immunophenotyping showed no MDS, 11 of 208 (5.3%) had cytogenetic aberrations. RUNX1/AML1 mutation screening was positive in 15% in the latter group. NRAS, MLL -PTD, NPM1, and JAK2V617F were detected in low frequencies, confirming MDS diagnosis in the respective cases. CONCLUSIONS: This report outlines the power of a combined diagnostic approach for suspected initial cases of MDS including immunophenotyping, cytogenetics, and molecular genetics with selected markers in addition to cytomorphology. Diagnostic algorithms should be developed, and immunophenotyping should be further validated for this specific indication. Cancer 2009. © 2009 American Cancer Society. [source] A comparison of GMS-A/AGECAT, DSM-III-R for dementia and depression, including subthreshold depression (SD),results from the Berlin Aging Study (BASE)INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 2 2003R. T. Schaub Abstract Background Empirical evaluation of the agreement between different diagnostic approaches is crucial for the understanding of epidemiological results in geriatric psychiatry. Objectives In this paper, we analyse differences between widely used diagnostic approaches of dementia and depression and offer evidence that diagnostic thresholds vary substantially on quantitative dimensions, but that conceptual and other differences between approaches must also been taken into account. Methods In an epidemiological study of n,=,516 persons, aged 70,103 years, we compared psychiatric diagnoses of dementia and depression obtained by GMS-A/HAS-AGECAT, DSM-III-R and clinician's diagnoses of subthreshold depression (SD). Results For depression, cumulative prevalence of clinician's diagnosis (including SD, GMS-A/HAS-AGECAT and DSM-III-R defined forms) was highest, followed by GMS-A/HAS-AGECAT-diagnosis and DSM-III-R, while for dementia DSM-III-R was followed by GMS-A/HAS-AGECAT. Overall agreement between DSM-III-R and GMS-A/HAS-AGECAT was moderate. Adapting thresholds for AGECAT resulted in slightly better diagnostic efficiency. Diagnostic disagreement was found predominantly for cases with intermediate symptom severity, supporting the hypothesis of differing thresholds between DSM-III-R and GMS-A/HAS-AGECAT, while cases with lower or higher symptom severity were similarily seen as cases or non-cases. Conclusion Disagreement is not only caused by conceptual differences, but also different thresholds of diagnostic algorithms. Adaptation of threshold levels should be feasible, depending on the purpose of the analysis. Copyright © 2003 John Wiley & Sons, Ltd. [source] ORIGINAL ARTICLE: Comparison of a point of care device against current laboratory methodology using citrated and EDTA samples for the determination of D-dimers in the exclusion of proximal deep vein thrombosisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2010P. M. BAKER Summary D-dimer estimation is a routine part of diagnostic algorithms for the exclusion of venous thromboembolism (VTE). We evaluated a point of care device, Biosite Triage (Inverness Medical UK, Cheshire, UK) for the estimation of D-dimers in both samples taken into citrate and EDTA against our routine laboratory D-dimer (Liatest D-dimer, Diagnostica Stago, Reading, UK) performed on the STA-R Evolution. With informed consent, 102 consecutive patients presenting with possible deep vein thrombosis (DVT) were enrolled and D-dimers along with Wells scores and compression ultrasonography (CUS) were recorded. Using the manufacturers' recommended cut offs of 500 ,g/l fibrinogen equivalent units and 400 ,g/l for the Stago and Triage, respectively, sensitivity, specificity, positive and negative predictive values were calculated. These were 1.00, 0.42, 0.17, and 1.00 for the Triage machine using citrate samples, 1.00, 0.32, 0.14, and 1.00 using EDTA samples and 1.00, 0.29, 0.16, and 1.00 for the Stago Liatest assay, respectively. Three patients had significantly higher results for the Stago Liatest D-dimer assay compared with the Biosite Triage device although ultrasound scans were negative. Conclusion: The Biosite Triage D-dimer assay performed on either citrate or EDTA samples is comparable with the Stago Liatest laboratory D-dimer assay when used in conjunction with clinical pretest probability scoring and CUS for the exclusion of DVT. [source] Recalibration methods to enhance information on prevalence rates from large mental health surveysINTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 1 2005N. A. Taub Abstract Comparisons between self-report and clinical psychiatric measures have revealed considerable disagreement. It is unsafe to consider these measures as directly equivalent, so it would be valuable to have a reliable recalibration of one measure in terms of the other. We evaluated multiple imputation incorporating a Bayesian approach, and a fully Bayesian method, to recalibrate diagnoses from a self-report survey interview in terms of those from a clinical interview with data from a two-phase national household survey for a practical application, and artificial data for simulation studies. The most important factors in obtaining a precise and accurate ,clinical' prevalence estimate from self-report data were (a) good agreement between the two diagnostic measures and (b) a sufficiently large set of calibration data with diagnoses based on both kinds of interview from the same group of subjects. From the case study, calibration data on 612 subjects were sufficient to yield estimates of the total prevalence of anxiety, depression or neurosis with a precision in the region of ±2%. The limitations of the calibration method demonstrate the need to increase agreement between survey and reference measures by improving lay interviews and their diagnostic algorithms. Copyright © 2005 Whurr Publishers Ltd. [source] Evidence-based algorithms for diagnosing and treating ventilator-associated pneumonia,JOURNAL OF HOSPITAL MEDICINE, Issue 5 2008Richard J. Wall MD Abstract BACKGROUND: Ventilator-associated pneumonia (VAP) is widely recognized as a serious and common complication associated with high morbidity and high costs. Given the complexity of caring for heterogeneous populations in the intensive care unit (ICU), however, there is still uncertainty regarding how to diagnose and manage VAP. OBJECTIVE: We recently conducted a national collaborative aimed at reducing health care,associated infections in ICUs of hospitals operated by the Hospital Corporation of America (HCA). As part of this collaborative, we developed algorithms for diagnosing and treating VAP in mechanically ventilated patients. In the current article, we (1) review the current evidence for diagnosing VAP, (2) describe our approach for developing these algorithms, and (3) illustrate the utility of the diagnostic algorithms using clinical teaching cases. DESIGN: This was a descriptive study, using data from a national collaborative focused on reducing VAP and catheter-related bloodstream infections. SETTING: The setting of the study was 110 ICUs at 61 HCA hospitals. INTERVENTION: None. MEASUREMENTS AND RESULTS: We assembled an interdisciplinary team that included infectious disease specialists, intensivists, hospitalists, statisticians, critical care nurses, and pharmacists. After reviewing published studies and the Centers for Disease Control and Prevention VAP guidelines, the team iteratively discussed the evidence, achieved consensus, and ultimately developed these practical algorithms. The diagnostic algorithms address infant, pediatric, immunocompromised, and adult ICU patients. CONCLUSIONS: We present practical algorithms for diagnosing and managing VAP in mechanically ventilated patients. These algorithms may provide evidence-based real-time guidance to clinicians seeking a standardized approach to diagnosing and managing this challenging problem. Journal of Hospital Medicine 2008;3:409,422. © 2008 Society of Hospital Medicine. [source] Contemporary management of pulmonary embolism: the answers to ten questionsJOURNAL OF INTERNAL MEDICINE, Issue 3 2010H. Bounameaux Abstract., Bounameaux H (Division of Angiology and Hemostasis, Department of Internal Medicine, University Hospitals of Geneva and Faculty of Medicine, Geneva, Switzerland). Contemporary management of pulmonary embolism: the answers to ten questions (Review). J Intern Med 2010; 268: 218,231. Pulmonary embolism (PE) cannot be diagnosed solely on a clinical basis, because of the lack of sensitivity and specificity of clinical signs and symptoms. Pulmonary angiography is invasive and resource demanding. Because the prevalence of PE is relatively low (20% or less) amongst individuals who are clinically suspected of having the disease, submitting all of them to imaging (multi-detector CT angiography or ventilation/perfusion lung scintigraphy) would not be cost-effective. Therefore, diagnostic algorithms have been developed that include clinical probability assessment and D-dimer measurement to select the patients who require noninvasive imaging. Once the diagnosis is suspected or confirmed, therapy must be started to avoid potentially fatal recurrence. Treatment starts for an initial 3-month period with a 5-day course of parenteral unfractionated or low-molecular-weight heparin or fondaparinux overlapping with and followed by oral vitamin K antagonists monitored to maintain an international normalized ratio of 2,3. This initial period of 3 months may then be followed by a long-term secondary prevention period in patients who experience an idiopathic thromboembolic event and are at low risk of bleeding. New oral anticoagulants that do require patient monitoring and might exhibit a more favourable benefit,risk balance are currently under extensive clinical testing and might change the situation in the near future. A critical appraisal of the contemporary management of suspected PE is given in this overview with the discussion of 10 practical questions. [source] Temporally and spectrally resolved fluorescence spectroscopy for the detection of high grade dysplasia in Barrett's esophagusLASERS IN SURGERY AND MEDICINE, Issue 1 2003T. Joshua Pfefer PhD Abstract Background and Objectives Temporal and spectral fluorescence spectroscopy can identify adenomatous colonic polyps accurately. In this study, these techniques were examined as a potential means of improving the surveillance of high grade dysplasia (HGD) in Barrett's esophagus (BE). Study Design/Materials and Methods Using excitation wavelengths of 337 and 400 nm, 148 fluorescence spectra, and 108 transient decay profiles (at 550,±,20 nm) were obtained endoscopically in 37 patients. Corresponding biopsies were collected and classified as carcinoma, HGD, or low risk tissue (LRT) [non-dysplastic BE, indefinite for dysplasia (IFD), and low grade dysplasia (LGD)]. Diagnostic algorithms were developed retrospectively using linear discriminant analysis (LDA) to separate LRT from HGD. Results LDA produced diagnostic algorithms based solely on spectral data. Moderate levels of sensitivity (Se) and specificity (Sp) were obtained for both 337 nm (Se,=,74%, Sp,=,67%) and 400 nm (Se,=,74%, Sp,=,85%) excitation. Conclusions In the diagnosis of HGD in BE, steady-state fluorescence was more effective than time-resolved data, and excitation at 400 nm excitation was more effective than 337 nm. While fluorescence-targeted biopsy is approaching clinical usefulness, increased sensitivity to dysplastic changes,possibly through modification of system parameters,is needed to improve accuracy levels. Lasers Surg. Med. 32:10,16,2003. © 2003 Wiley-Liss, Inc. [source] Immunohistochemical estimation of cell cycle entry and phase distribution in astrocytomas: applications in diagnostic neuropathologyNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 5 2005Ian S. Scott An immunohistochemical method for assessing cell cycle phase distribution in neurosurgical biopsies would enable such data to be incorporated into diagnostic algorithms for the estimation of prognosis and response to adjuvant chemotherapy in glial neoplasms, without the requirement for flow cytometric analysis. Paraffin-embedded sections of intracerebral gliomas (n = 48), consisting of diffuse astrocytoma (n = 9), anaplastic astrocytoma (n = 8) and glioblastoma (n = 31), were analysed by immunohistochemistry using markers of cell cycle entry, Mcm-2 and Ki67, and putative markers of cell cycle phase, cyclins D1 (G1-phase), cyclin A (S-phase), cyclin B1 (G2-phase) and phosphohistone H3 (Mitosis). Double labelling confocal microscopy confirmed that the phase markers were infrequently coexpressed. Cell cycle estimations by immunohistochemistry were corroborated by flow cytometric analysis. There was a significant increase in Mcm-2 (P < 0.0001), Ki67 (P < 0.0001), cyclin A (P < 0.0001) and cyclin B1 (P = 0.002) expression with increasing grade from diffuse astrocytoma through anaplastic astrocytoma to glioblastoma, suggesting that any of these four markers has potential as a marker of tumour grade. In a subset of glioblastomas (n = 16) for which accurate clinical follow-up data were available, there was a suggestion that the cyclin A:Mcm-2 labelling fraction might predict a relatively favourable response to radical radiotherapy. These provisional findings, however, require confirmation by a larger study. We conclude that it is feasible to obtain detailed cell cycle data by immunohistochemical analysis of tissue biopsies. Such information may facilitate tumour grading and may enable information of prognostic value to be obtained in the routine diagnostic laboratory. [source] The Reliable Electrocardiographic Diagnosis of Regular Broad Complex Tachycardia: A Holy Grail That Will Forever Elude the Clinician's Grasp?PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2002ERNEST W. LAU LAU, E.W., et al.: The Reliable Electrocardiographic Diagnosis of Regular Broad Complex Tachycardia: A Holy Grail That Will Forever Elude the Clinician's Grasp? The reliable and accurate diagnosis of regular broad complex tachycardia (BCT) by the ECG is a goal that has eluded clinicians and electrophysiologists alike for years. This article explores the reason for this by first giving an historical account on the development of the subject. Next, the electrophysiological mechanisms of ventricular tachycardia, supraventricular tachycardia with aberrant conduction, and preexcited tachycardia, the three main differential diagnoses for regular BCT, according to the latest knowledge from cellular and clinical electrophysiology study will be reviewed, together with considerations on how such understanding may help account for the manifestations of these tachycardias on the ECG and the difficulty in distinguishing between them. Finally, the use of electrophysiological study as the criterion standard for diagnosing regular BCT, as has been the case in most studies on the subject, will be critiqued in terms of the potential for misdiagnosis by the method and the use of any ECG diagnostic algorithms developed with its aid in the acute medical care setting. [source] Is GRP78/BiP a potential salivary biomarker in patients with rheumatoid arthritis?PROTEOMICS - CLINICAL APPLICATIONS, Issue 3 2010Laura Giusti Abstract Purpose: In the last few years, serum and joint synovial fluid have been extensively analyzed for the proteomic research of rheumatoid arthritis (RA) biomarkers. Nonetheless, to date, there have been no studies investigating salivary biomarkers in this condition. Therefore, aim of this study is to investigate the presence of potential biomarkers of RA in human whole saliva. Experimental design: We combined 2-DE and MS to analyze the whole saliva protein profile of 20 RA patients in comparison with 20 sex- and age-matched healthy subjects. Results: Eight salivary proteins resulted differentially expressed, namely calgranulin A, calgranulin B, apolipoprotein A-1, 6-phosphogluconate dehydrogenase, peroxiredoxin 5, epidermal fatty acid-binding protein, 78,kDa glucose-regulated protein precursor (GRP78/BiP), and 14-3-3 proteins. It is particularly interesting that chaperone GRP78/BiP showed the greatest increase in RA patients. This finding was validated by Western Blot analysis and the over-expression of GRP78/BiP appear to be distinctive of RA and drugs treatment independent. Conclusions and clinical relevance: This study provides a rationale for further studies aimed at evaluating any correlation between GRP78/BiP and different clinical/serological aspects of the disease in order to improve the diagnostic algorithms of RA. [source] The use of a fixed high sensitivity to evaluate five D -dimer assays' ability to rule out deep venous thrombosis: a novel approachBRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2005Scott M. Stevens Summary Suspected deep venous thrombosis (DVT) is difficult to refute without complex diagnostic algorithms and expensive testing. We analysed five d -dimer assays' utility for exclusion of suspected DVT during a prospective clinical cohort trial, choosing a highly sensitive cut-off value at which to compare the assays. Assays were performed on 436 consecutive patients who were referred with symptoms that suggested a first episode of DVT. Venous thromboembolism (VTE) was defined as positive findings on comprehensive duplex ultrasonography or any episode, or complication of VTE detected during 3 months of clinical follow-up. All five assays were performed in 377 patients. At a highly sensitive cut-off value, all five assays reliably excluded DVT in the study population. While the choice of a highly sensitive cut-off value reduced the specificity of all the assays, the change in specificity differed between tests. Our findings suggest that a second-generation d -dimer assay could be used as a stand-alone test to rule out suspected DVT when a highly sensitive cut-off value is chosen. These findings should be subjected to a prospective management study, as a small reduction in sensitivity from our findings could result in a clinically relevant decrease in negative predictive value. [source] | |||||||||||||||||||