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1.
Martin Griebe Michael Daffertshofer Mark Stroick Magdalena Syren Parviz Ahmad-Nejad Michael Neumaier Juergen Backhaus Michael G. Hennerici Marc Fatar 《Neuroscience letters》2007
Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and β-amyloid1–42 proteins to a novel approach – Fourier transformed infrared (FT-IR) spectroscopy – a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. β-Amyloid1–42 was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/β-amyloid1–42 quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and β-amyloid1–42 protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool. 相似文献
2.
医院医疗设备项目成本效益分析方法探讨 总被引:8,自引:1,他引:8
在逐步走向以成本控制为核心的设备经济管理的形势下,对运用于医疗设备项目的经济评价方面的各种经济学分析办法进行了探讨,运用财务贴现概念,提出了以净现值分析和修正的回收期方法来估算设备预期成本效益. 相似文献
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BackgroundImmunoassays provide a rapid tool for the screening of drugs-of-abuse (DOA). However, results are presumptive and confirmatory testing is warranted. To reduce associated cost and delay, laboratories should employ assays with high positive and negative predictive values (PPVs and NPVs). Here, we compared the results of urine drug screens on cobas 6000 (cobas) and ARCHITECTi2000 (ARCHITECT) platforms for six drugs against LC-MS/MS to assess the analytical performance of these assays.MethodsEighty nine residual urine specimens, which tested positive for amphetamine, THC-COOH, benzoylecgonine, EDDP, opiates and/or oxycodone during routine drug testing, were stored frozen until later confirmation by LC-MS/MS. Immunoassays were performed on cobas and ARCHITECT using a split sample. A third aliquot from these samples was tested by LC-MS/MS to assess the percentage of false positive, false negative, true positive and true negative results and calculate the PPVs and NPVs for each immunoassay.ResultsThe PPVs of THC-COOH and EDDP assays were 100% on both platforms. Suboptimal PPVs were achieved for oxycodone (cobas, 57.1% vs ARCHITECT, 66.7%), amphetamine (77.8 vs. 100%), opiates (80.0 vs. 84.6%) and benzoylecgonine (88.9 vs. 84.2%) assays. The NPV was 100% for cobas and ARCHITECT oxycodone assays. Lower NPVs were achieved for THC-COOH (cobas, 28.6% vs ARCHITECT, 25.0%), EDDP (72.7% for both assays), benzoylecgonine (74.4% vs 73.8%), amphetamine (83.3% vs 82.8%) and opiates (100% vs 85.3%).ConclusionOverall, cobas and ARCHITECT urine drug screens have comparable analytical performance. Confirmatory testing is warranted for positive test results especially for oxycodone, amphetamine, opiates and cocaine. Negative drug screen results must be interpreted with caution especially for THC-COOH, EDDP, benzoylecgonine, amphetamine and opiates. 相似文献
5.
James L. Januzzi Annabel A. Chen-Tournoux Robert H. Christenson Gheorghe Doros Judd E. Hollander Phillip D. Levy John T. Nagurney Richard M. Nowak Peter S. Pang Darshita Patel W. Franklin Peacock E. Joy Rivers Elizabeth L. Walters Hanna K. Gaggin 《Journal of the American College of Cardiology》2018,71(11):1191-1200
Background
Contemporary reconsideration of diagnostic N-terminal pro–B-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.Objectives
This study sought to evaluate the diagnostic performance of NT-proBNP for acute HF in patients with dyspnea in the emergency department (ED) setting.Methods
Dyspneic patients presenting to 19 EDs in North America were enrolled and had blood drawn for subsequent NT-proBNP measurement. Primary endpoints were positive predictive values of age-stratified cutoffs (450, 900, and 1,800 pg/ml) for diagnosis of acute HF and negative predictive value of the rule-out cutoff to exclude acute HF. Secondary endpoints included sensitivity, specificity, and positive (+) and negative (?) likelihood ratios (LRs) for acute HF.Results
Of 1,461 subjects, 277 (19%) were adjudicated as having acute HF. The area under the receiver-operating characteristic curve for diagnosis of acute HF was 0.91 (95% confidence interval [CI]: 0.90 to 0.93; p < 0.001). Sensitivity for age stratified cutoffs of 450, 900, and 1,800 pg/ml was 85.7%, 79.3%, and 75.9%, respectively; specificity was 93.9%, 84.0%, and 75.0%, respectively. Positive predictive values were 53.6%, 58.4%, and 62.0%, respectively. Overall LR+ across age-dependent cutoffs was 5.99 (95% CI: 5.05 to 6.93); individual LR+ for age-dependent cutoffs was 14.08, 4.95, and 3.03, respectively. The sensitivity and negative predictive value for the rule-out cutoff of 300 pg/ml were 93.9% and 98.0%, respectively; LR? was 0.09 (95% CI: 0.05 to 0.13).Conclusions
In acutely dyspneic patients seen in the ED setting, age-stratified NT-proBNP cutpoints may aid in the diagnosis of acute HF. An NT-proBNP <300 pg/ml strongly excludes the presence of acute HF. 相似文献6.
《Diagnostic and interventional imaging》2015,96(9):941-946
PurposeThe goal of this study was to evaluate the diagnostic accuracy of a software program that automatically analyzes the liver surface to diagnose significant fibrosis, by comparing it to the subjective analysis of a radiologist and to transient elastography (Fibroscan®).Patients and methodsOne hundred fourteen patients with chronic liver disease were included in the study. They underwent liver biopsy, FibroScan® and ultrasonographic examination of the liver surface. The liver surface was analyzed by a software program that gave a score of surface irregularities. This evaluation was compared to subjective analysis by a radiologist expert in liver imaging and by two general radiologists.ResultsFifty percent of the patients had significant fibrosis according to the METAVIR score. The AUROC for the diagnosis of significant fibrosis by the software program was 0.80 (95%CI: 0.71–0.87), which was equivalent (P = 0.86) to that of FibroScan® (0.81; 95%CI: 0.71–0.89). Results of the subjective analysis by the expert radiologist were poorer than those of the software analysis (P = 0.02) (AUROC = 0.66; 95%CI: 0.56–0.75). Interobserver agreement among radiologists was poor (0.25 < kappa < 0.37).ConclusionComputer-assisted liver surface analysis was better than subjective analysis, and similar to that of the FibroScan®. This method could be useful for the diagnosis of significant fibrosis in patients with chronic hepatitis and complementary to the other non-invasive diagnostic tests. 相似文献
7.
Bérangère Joly Alain Stepanian David Hajage Sandrine Thouzeau Sophie Capdenat Paul Coppo Agnès Veyradier 《Thrombosis research》2014
Introduction
Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy (TMA), related to a severe functional deficiency of ADAMTS13 activity (< 10% of normal). ADAMTS13 activity is thus crucial to confirm the clinical suspicion of TTP, to distinguish it from other TMAs, and to perform the follow-up of TTP patients.Material and methods
We compared the performance of the commercial chromogenic assay Technozym® ADAMTS13 Activity ELISA (chromogenic VWF73 substrate, Chr-VWF73, Technoclone, Vienna, Austria), to that of our in-house FRETS-VWF73 used as reference method. A large group of 247 subjects (30 healthy volunteers and 217 patients with miscellaneaous TMAs) was studied.Results
The lower limit of detection of the Chr-VWF73 was 3%, which is well adapted to the clinically relevant threshold for TTP diagnosis (10%). Our results showed a reasonable agreement between FRETS-VWF73 and Chr-VWF73 assays to distinguish samples with an ADAMTS13 activity < 10% from those with an ADAMTS13 activity > 10%. However, Chr-VWF73 assay provided false negative results in ~ 12% of acute TTP patients. Inversely, the Chr-VWF73 assay globally underestimated ADAMTS13 activity in detectable values ranging from 11 to 100% (with a great variability compared to FRETS-VWF73), which may be a concern for the follow-up of TTP patients in remission.Conclusion
In-house assays developed and performed by expert laboratories remain the reference methods that should be used without limitation to control values provided by commercial assays when needed. Also, the development of an international reference preparation will be crucial to improve standardization. 相似文献8.
Yoon RK Smaldone AM Edelstein BL 《Journal of the American Dental Association (1939)》2012,143(7):756-763
BackgroundEarly childhood caries (ECC) is prevalent and consequential. Risk assessment tools have been proposed that can be used to identify children who require intensive interventions. In this study, the authors compare four approaches for identifying children needing early and intensive intervention to prevent or minimize caries experience for their accuracy and clinical usefulness.MethodsThe authors screened 229 predominantly low-income Hispanic children younger than 3 years with ECC and 242 without ECC by using the American Academy of Pediatric Dentistry's Caries-risk Assessment Tool (CAT) and the optional screening measure of culturing Streptococcus mutans. The authors compared four approaches (CAT, CAT minus socioeconomic status, CAT minus socioeconomic status plus mutans streptococci [MS] and MS alone) for accuracy and clinical usefulness.ResultsThe results of the CAT demonstrated high sensitivity (100.0 percent) and negative predictive value (NPV) (100.0 percent) but low specificity (2.9 percent) and positive predictive value (PPV) (49.4 percent). The MS culture alone had the highest combination of accuracy and clinical usefulness (sensitivity, 86.5 percent; specificity, 93.4 percent; PPV, 92.5 percent; NPV, 87.9 percent). When we removed the socioeconomic status element, the CAT's performance improved.ConclusionsSalivary culture of MS alone in a population of young, low-income Hispanic childrenoutperformed the CAT and variations on the CAT for test accuracy (sensitivity and specificity) and clinical usefulness (predictive values).Clinical ImplicationsScreening for ECC by using salivary MS cultures and variations on the CAT are promising approaches for identifying children who need early and intensive intervention to prevent or minimize caries experience. 相似文献
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