One-Minute Finger Pulsation Measurement for Diabetes Rapid Screening with 1.3% to 13% False-Negative Prediction Rate

A rapid screening method for identification of clinic patients with pharyngitis who are carrying group A beta-hemolytic streptococci and for teaching residents the values and limitations of the culture-disk approach to identification has been reviewed as developed for a busy clinic and a busy hospital laboratory. Identification of positive cultures in less than 24 hours, using Taxos A disk and specific fluorescent antibody uptake, resulted in 12% apparent false-positive and 3.6% false-negative reports. However, when viewed in the light of the techniques used for verifying results, there were probably 3% false-positive and 3% false-negative reports. The screening method is considered acceptably reliable and practical as a laboratory tool and a resident teaching device.

Download Full-text

High-Throughput Genotyping of Thiopurine S-Methyltransferase by Denaturing HPLC

Clinical Chemistry ◽

10.1093/clinchem/47.3.548 ◽

2001 ◽

Vol 47 (3) ◽

pp. 548-555 ◽

Cited By ~ 59

Author(s):

Elke Schaeffeler ◽

Thomas Lang ◽

Ulrich M Zanger ◽

Michel Eichelbaum ◽

Matthias Schwab

Keyword(s):

High Throughput ◽

Direct Sequencing ◽

False Negative ◽

Rapid Screening ◽

Tpmt Activity ◽

Polymorphism Analysis ◽

Specific Pcr ◽

Restriction Fragment Polymorphism ◽

Allele Specific ◽

Tpmt Gene

Abstract Background: The thiopurine S-methyltransferase (TPMT) genetic polymorphism has a significant clinical impact on the toxicity of thiopurine drugs, which are used in the treatment of leukemia and as immunosuppressants. To date, 10 mutant alleles are known that are associated with intermediate or low TPMT activity. To facilitate rapid screening of clinically relevant TPMT mutations, we developed a strategy of high-throughput genotyping by applying denaturing HPLC (DHPLC). Methods: To test the specificity and efficiency of the DHPLC method, 98 DNA samples from a selected population of patients receiving thiopurine therapy or with previous thiopurine withdrawal were analyzed for the most frequent mutant TPMT alleles, *2 and *3A, which contain key mutations in exons 5, 7, and 10 to identify clearly different elution profiles. All fragments were examined by direct sequencing. Additionally, to test the sensitivity of DHPLC analysis, genotyping for the *2 and *3A alleles of all 98 DNA samples was performed by PCR-based methods (PCR-restriction fragment polymorphism analysis and allele-specific PCR). Results: The presence of mutations discriminating for alleles *2, *3A, *3C, and *3D, as well as various silent and intron mutations, were correctly predicted by DHPLC in 100% of the samples as confirmed by direct sequencing. Comparison with PCR-based methods for alleles *2 and *3 produced an agreement of 100% with no false-negative signals. Conclusions: DHPLC offers a highly sensitive, rapid, and efficient method for genotyping of the relevant TPMT mutations, discriminating at least for alleles *2 and *3, in clinical and laboratory practice. Additionally, DHPLC allows a simultaneous screening for novel genetic variability in the TPMT gene.

Download Full-text

Validation of a Dissociation Enhanced Lanthanide Fluorescence Immunoassay for the Screening of 17 -Estradiol in Bovine Serum According to European Union Decision 2002/657/EC

Journal of AOAC International ◽

10.1093/jaoac/90.5.1427 ◽

2007 ◽

Vol 90 (5) ◽

pp. 1427-1431 ◽

Cited By ~ 3

Author(s):

Daniela Scalas ◽

Stefania Squadrone ◽

Marilena Gili ◽

Daniela Marchis ◽

Marino Prearo ◽

...

Keyword(s):

European Union ◽

Bovine Serum ◽

False Negative ◽

Screening Tests ◽

Rapid Screening ◽

Fluorescence Immunoassay ◽

Serum Samples ◽

Related Substances ◽

The Matrix ◽

Negative Effect

Abstract A validation study was carried out in order to evaluate the performances of a dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) for rapid screening of 17 -Estradiol in bovine serum. This validation was performed according to European Union (EU) Decision 2002/657/EC, which establishes criteria and procedures for determination of detection capability (CC), selectivity/specificity, and applicability/ruggedness/stability for qualitative screening tests. To determine these performance characteristics, 20 blank serum samples of cattle were collected and spiked with 17 -Estradiol at 40 pg/mL, corresponding to the maximum residue limit permitted by Italian legislation. According to the EU Decision CC criterion, spiked samples must have <5 probability to be classified as a false negative. 17 -Estradiol was detected in each spiked sample, and the CC results were <40 pg/mL. There was also no observed interference effect due to chemically related substances or from the matrix. Moreover, slight variations of some critical factors in the DELFIA procedure, deliberately introduced for ruggedness evaluation, did not result in any negative effect on the 17 -Estradiol detection. The proposed method is suitable for qualitative screening analysis of 17 -Estradiol according to EU performance requirements.

Download Full-text

Performance criteria for rapid screening methods to detect mycotoxins

World Mycotoxin Journal ◽

10.3920/wmj2014.1710 ◽

2014 ◽

Vol 7 (4) ◽

pp. 439-447 ◽

Cited By ~ 8

Author(s):

C. von Holst ◽

J. Stroka

Keyword(s):

False Negative ◽

Screening Method ◽

Performance Criterion ◽

Performance Criteria ◽

Rapid Screening ◽

Cost Ratio ◽

Screening Methods ◽

Method Performance ◽

Official Control ◽

The Impact

The paper describes the validation of screening methods that are used for official control to classify samples into negative and suspect positive samples. The concept is based on the principle that negative samples are considered as compliant, whereas suspect positive samples need to be re-analysed with confirmatory methods. An important performance criterion often used is a maximum value of 5% for the probability of false negative results obtained on samples that contain the analyte at the legal limit. Since the result of analysis is a binary decision, specific validation schemes need to be applied. The paper places emphasis on practical aspects of the calculation of the method performance characteristics, which are required to check whether the methods fulfil the performance criterion. The paper shows that screening methods based on a visual inspection, e.g. a dipstick, require special data treatment. In contrast there are many methods where the classification into negative and suspect positive samples is based on the comparison of a measured response against a cut-off value. This type of methods can be validated with quantitative statistics. The paper also elaborates on the calculation of the rate of false positive results of compliant samples. In addition the impact on the economical aspect of the use of the screening method is estimated, taking into account external factors such as the cost ratio between the screening and the confirmatory method and the occurrence of non-compliant samples in the entire population of the samples.

Download Full-text

Hybrid Data Mining to Reduce False Positive and False Negative Prediction in Intrusion Detection System

Advances in Intelligent Systems and Computing - Advances in Information and Communication Networks ◽

10.1007/978-3-030-03405-4_1 ◽

2018 ◽

pp. 1-12

Author(s):

Bala Palanisamy ◽

Biswajit Panja ◽

Priyanka Meharia

Keyword(s):

Data Mining ◽

Intrusion Detection ◽

False Positive ◽

Intrusion Detection System ◽

Detection System ◽

False Negative ◽

Negative Prediction ◽

Hybrid Data

Download Full-text

Comparative Studies of Nucleic Acid Hybridization Assay for Listeria in Foods

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/71.3.669 ◽

1988 ◽

Vol 71 (3) ◽

pp. 669-673 ◽

Cited By ~ 3

Author(s):

Jeffrey D Klinger ◽

Andrew Johnson ◽

Daniel Croan ◽

Pauline Flynn ◽

Kevan Whippie ◽

...

Keyword(s):

Nucleic Acid ◽

Environmental Samples ◽

False Negative ◽

False Negative Rate ◽

Nucleic Acid Hybridization ◽

Hybridization Assay ◽

Rapid Screening ◽

Bacterial Strains ◽

Synthetic Dna ◽

Conventional Culture

Abstract A nucleic acid hybridization assay has been developed for Listeria spp. in dairy foods and environmental samples. The assay is based on detection of unique Listeria 16S rRNA sequences by using a 32Plabeled synthetic DNA probe. Inclusivity and exclusivity of the probe were confirmed with 139 Listeria isolates representing all known species, and 73 non-Listeria bacterial strains. In this paper, we present results from our preliminary studies comparing the hybridization assay with conventional culture on a total of 575 specimens that represent a variety of inoculated and uninoculated foods and environmental samples. The assay, which is done in a filter manifold format after 2 days of cultural enrichment, requires a total assay time of less than 2.5 days. The false-negative rate for all sample groups tested using the GENE-TRAK hybridization assay was less than the rate for culture. Thus, the new assay allows rapid screening of the indicated product groups and provides reliable numerical results

Download Full-text

Comparison between VIDAS Automatic Enzyme-Linked Fluorescent Immunoassay and Culture Method for Salmonella Recovery from Pork Carcass Sponge Samples

Journal of Food Protection ◽

10.4315/0362-028x-65.10.1656 ◽

2002 ◽

Vol 65 (10) ◽

pp. 1656-1659 ◽

Cited By ~ 16

Author(s):

KUANG-SHENG YEH ◽

CHIN-EN TSAI ◽

SHIH-PING CHEN ◽

CHAO-WEI LIAO

Keyword(s):

False Negative ◽

Screening Method ◽

Culture Method ◽

Automated System ◽

Rapid Screening ◽

Assay Method ◽

Intensive Culture ◽

Negative Results ◽

False Negative Results ◽

Potential Alternative

VIDAS Salmonella (VIDAS-SLM) is an automated system that uses the enzyme-linked fluorescent assay method to detect Salmonella species. This study evaluated the efficacy of the VIDAS-SLM method in detecting Salmonella species in pork carcass sponge samples gathered from 10 slaughter plants in Taiwan. Two hundred fifty-seven pork carcass sponge samples were screened by the VIDAS-SLM method and by the culture method in parallel. While 18 sponge samples were found to test positive by both methods, the VIDAS-SLM method detected four additional positive samples for which the culture method failed to recover Salmonella. The specificity of the VIDAS-SLM method was found to be 0.98, and its sensitivity was 1.0, since no false-negative results occurred. Artificially inoculated Salmonella at concentrations as low as 5.0 × 100 CFU/ml was detected in the heat-inactivated sponge sample in the presence or absence of 5.0 × 104 CFU of Citrobacter freundii per ml. Thus, the VIDAS-SLM method is a rapid screening method and a potential alternative to the time- and labor-intensive culture method.

Download Full-text

Elevated-Temperature, Colorimetric, Monoclonal, Enzyme-Linked Immunosorbent Assay for Rapid Screening of Salmonella in Foods: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/77.2.374 ◽

1994 ◽

Vol 77 (2) ◽

pp. 374-394 ◽

Cited By ~ 7

Author(s):

Karl F Eckner ◽

Wendy A Dustman ◽

Michael S Curiale ◽

Russell S Flowers ◽

Barbara J Robison

Keyword(s):

Elevated Temperature ◽

Immunosorbent Assay ◽

Collaborative Study ◽

False Negative ◽

Culture Method ◽

Soy Flour ◽

Rapid Screening ◽

Enzyme Linked Immunosorbent Assay ◽

Elisa Method ◽

Milk Chocolate

Abstract A collaborative study was performed by 30 laboratories in 3 sets of trials to validate a modified colorimetric monoclonal enzyme-linked immunosorbent assay (ELISA) method for Salmonella detection. The modifications to the current methodology included incubation of enrichments and postenrichments at an elevated temperature, addition of novobiocin to the M-broth post-enrichment, and elimination of the centrifugation and agitation steps. Five artificially contaminated foods (nonfat dry milk, milk chocolate, dried egg, ground black pepper, and soy flour) and 1 naturally contaminated food (raw ground turkey) were analyzed. The artificially contaminated foods were inoculated with individual Salmonella serotypes at a high (10–50 cells/25 g) and low (1–5 cells/25 g) contamination level. Results from the modified ELISA method were compared to the Bacteriological Analytical Manual (BAM)/AOAC culture method. In 2 of the food products, milk chocolate and pepper, a number of laboratories isolated Salmonella from uninoculated control samples, thus invalidating their data. As a result, there were too few laboratories remaining with valid data, and these foods were repeated. In the completed study, there were 11 false negative results obtained by the modified ELISA method, while there were 28 false negatives produced by the BAM/AOAC procedure. There were 11 ELISA positive assays which could not be confirmed by culture methods. Statistically, there were no differences between the modified, colorimetric, monoclonal ELISA and the reference culture method in all foods except raw turkey, where the ELISA method was more productive. The colorimetric monoclonal enzyme immunoassay (Salmonella-Tek) method for detecting Salmonella in all foods has been adopted first action by AOAC INTERNATIONAL.

Download Full-text

Simplified microscopy for rapid detection of significant bacteriuria in random urine specimens

Journal of Clinical Microbiology ◽

10.1128/jcm.7.3.286-289.1978 ◽

1978 ◽

Vol 7 (3) ◽

pp. 286-289

Author(s):

G K Barbin ◽

J D Thorley ◽

J A Reinarz

Keyword(s):

False Negative ◽

Rapid Screening ◽

Negative Results ◽

Microscopy Technique ◽

Gram Staining ◽

False Negative Results ◽

Significant Bacteriuria ◽

Urine Microscopy ◽

Positive Results ◽

Urine Specimens

Simplified urine microscopy, nitrite testing, and dipstick culture were compared with urine loop streak culture colony counts in 219 random voided specimens to determine the accuracy of the three rapid screening techniques. Nitrite testing resulted in 65% false negative results, which could not be significantly improved by incubation at 37 degrees C but which could be improved by adding nitrate substrate before incubation. Dipstick culture could not be quantitated until after 18 h of incubation. A new, simplified microscopy technique, using unspun, unstained urine, resulted in 4% false negative results and 4% false positive results in specimens containing over 10(5) organisms per ml and was the best method Centrifuges, Gram staining reagents, and counting chambers are not necessary for accurate microscopic screening of random urine specimens for the presence of bacteriuria by this technique, and the results are immediately available.

Download Full-text

Diagnostic screening of urban soil contaminants using diffuse reflectance spectroscopy

Soil Research ◽

10.1071/sr08068 ◽

2009 ◽

Vol 47 (4) ◽

pp. 433 ◽

Cited By ~ 31

Author(s):

J. G. P. Bray ◽

R. Viscarra Rossel ◽

A. B. McBratney

Keyword(s):

Heavy Metals ◽

Prediction Accuracy ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

False Negative ◽

Reflectance Spectroscopy ◽

Screening Tests ◽

Rapid Screening ◽

Diagnostic Screening ◽

Soil Contaminants

There is increasing demand for cheap and rapid screening tests for soil contaminants in environmental consultancies. Diffuse reflectance spectroscopy (DRS) in the visible-near infrared (vis-NIR) and mid infrared (MIR) has the potential to meet this demand. The aims of this paper were to develop diagnostic screening tests for heavy metals and polycyclic aromatic hydrocarbons (PAH) in soil using vis-NIR and MIR DRS. Cadmium, copper, lead, and zinc were analysed, as were total PAH and benzo[a]pyrene. An ordinal logistic regression technique was used for the screening and predictions of either contaminated or uncontaminated soil at different thresholds. We calculated the rates of false positive and false negative predictions and derived Receiver Operating Characteristic curves to explore how the choice of a threshold affects their proportion. Zinc and copper had the best prediction accuracies of the heavy metals, with 89% and 85%, respectively. Cadmium and lead had the lowest prediction accuracies, with 68% and 67%, respectively. PAH predictions averaged 78.9%. With an average prediction accuracy of 79.9%, MIR analysis was only slightly more accurate than vis-NIR analysis, which had an average prediction accuracy of 77.5%. However, vis-NIR may be used in situ, thereby reducing cost and time of analysis and providing diagnosis in ‘real-time’. DRS in the vis-NIR can substantially decrease both the time and cost associated with screening for soil contaminants.

Download Full-text