scholarly journals Microtransponder-Based Multiplex Assay for Genotyping Cystic Fibrosis

2007 ◽  
Vol 53 (7) ◽  
pp. 1372-1376 ◽  
Author(s):  
Xin Lin ◽  
James A Flint ◽  
Marco Azaro ◽  
Thomas Coradetti ◽  
Wesley M Kopacka ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
African American ◽  
Multiplex Pcr ◽  
False Positive ◽  
False Negative ◽  
Multiplex Assay ◽  
Specific Primer ◽  
Fluorescence Measurements ◽  
Allele Specific ◽  
Analysis Platform

Abstract Background: We developed and evaluated a genotyping assay for detection of 50 cystic fibrosis (CF) mutations. The assay is based on small (500 μm) electronic chips, radio frequency (RF) microtransponders (MTPs). The chips are analyzed on a unique fluorescence and RF readout instrument. Methods: We divided the CF assay into 4 panels: core, Hispanic, African-American, and Caucasian. We amplified 18 CF transmembrane regulator (CFTR) DNA fragments covering 50 mutations by use of multiplex PCR using 18 CFTR gene-specific primer pairs. PCR was followed by multiplex allele-specific primer extension (ASPE) reactions and hybridization to capture probes synthesized on MTPs. We used 100 ASPE primers and 100 capture probes. We performed fluorescence measurements of hybridized MTP kits and assay analysis using a custom automated bench-top flow instrument. Results: We validated the system by performing the assay on 23 commercial DNA samples in an internal study and 32 DNA samples in an external study. For internal and external studies, correct calls were 98.8% and 95.7%, false-positive calls 1.1% and 3.9%, and false-negative calls 0.12% and 0.36%, respectively. Conclusions: The MTP-based multiplex assay and analysis platform can be used for CF genotyping.

The Decline of the Sweat Test

1973 ◽  
Vol 12 (7) ◽  
pp. 450-453 ◽  
Author(s):  
Lewis E. Gibson
Keyword(s):  
Cystic Fibrosis ◽  
False Positive ◽  
False Negative ◽  
Sweat Test ◽  
Test Results ◽  
Faraday’S Law ◽  
Chest Clinic ◽  
Prognostic Implications

Eleven false positive and eight false negative sweat test results were found in a survey of 254 chest clinic patients thought to have cystic fibrosis. A larger and earlier study had given essentially no false results. Comments are made concerning the physiology of sweating, the pathophysiology of cystic fibrosis, and the application of Faraday's Law. Failure to appreciate these principles has led to inappropriate and dubious modifications of the sweat test pro cedure. A strong plea is made for the careful performance of a basically sound procedure which has such profound genetic and prognostic implications.

scholarly journals OPTIMIZATION OF MOLECULAR DETECTION FOR Vibrio cholerae and PATHOGENIC Escherichia coli USING MULTIPLEX PCR

2021 ◽  
pp. e299
Author(s):  
Diana Elizabeth Waturangi ◽  
Jason Petrus ◽  
Rico Kosasih ◽  
Felicia Roseline
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Vibrio Cholerae ◽  
False Positive ◽  
Rapid Detection ◽  
Pathogenic Bacteria ◽  
Molecular Detection ◽  
False Negative ◽  
E Coli ◽  
Pathogenic Escherichia Coli

Vibrio cholerae and pathogenic Escherichia coli were considered as main causative agent foodborne diseases especially in many developing countries, such as Indonesia. Thereby, rapid detection of these pathogenic bacteria is necessary to treat food-borne related diseases causing by these bacteria. In this case, multiplex PCR allows multiple genes amplification in one reaction thereby enable to perform rapid detection of these pathogenic bacteria. The objective of this study is to optimize uniplex and multiples PCR of V. cholerae and pathogenic E. coli detection and determine the sensitivity and specificity of this assays. We used various virulence genes for each pathogenic bacterium as markers for uniplex and multiplex PCR detection. Based on this research, the optimum results of V. cholerae and pathogenic E. coli were obtained with a primer concentration of 16 µM for ctxA and ompU, 30 µM for ace, and 50 µM for zot, and toxR; 2 µM for elt and 5 µM for stx, respectively. Finally, based on the standardization method by ISO/TS 20836 these assays had 0% false positive, 0% false negative, 100% specificity, and 100% sensitivity; 0% false positive, 4% false negative, 100% specificity, and 96% sensitivity for V. cholerae and pathogenic E. coli respectively. The optimized method was qualified to be used as a molecular detection for V. cholerae as well as EHEC and ETEC detection according to ISO/TS 20836 (2017)  from drinking water samples.

Molecular Typing for Kidd Blood Group in Taiwan.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4174-4174
Author(s):  
Cheng-Hwai Tzeng ◽  
Jau-Yi Lyou ◽  
Pei-Shan Chen ◽  
Hsueng-Mei Liu ◽  
Ying-Ju Chen ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Blood Group ◽  
Whole Blood ◽  
Chinese People ◽  
Specific Primer ◽  
Blood Samples ◽  
Single Tube ◽  
Three Samples ◽  
Allele Specific ◽  
Whole Blood Samples

Abstract Background:The Kidd (JK) blood group system is clinically important intransfusion medicine. Alloantibodies to antigens in this system may be produced following blood transfusion or during pregnancy and can result in serious hemolytic transfusion reactions and hemolytic disease of the newborn (HDN). The two major codominant alleles of the JK gene, Jka and Jkb, have a similar frequency in Caucasian populations (0.51 and 0.49, respectively) and define 3 common phenotypes Jk(a+b+), Jk(a+b-), Jk(a-b+), while frequency of Jk(a-b-) or Jknull phenotype is exceedingly rare. Many individuals of Polynesian extraction have been identified as Jknull. Its frequency and molecular characterization for Chinese people in Taiwan, however, has not yet been clarified. Study design and methods: By using the lately developed single-tube allele-specific primer/multiplex PCR technique, a total of 320 random whole blood samples were analyzed. In addition, three samples already serologically proven as Jknull phenotype in our Lab were also investigated. Results: None of the 320 random whole blood samples was serologically typed as Jk(a-b-), while the frequencies of three other phenotypes were 47.5% for Jk(a+b+), 23.1% for Jk(a+b-), and 29.4% for Jk(a-b+). Interestingly, two Jka/Jk and four Jkb/Jk were identified, resulting in a gene frequency of Jka - 46.72%, Jkb - 52.34% and silent Jk - 0.94%. As for the three samples of Jknull phenotype all belonged to the so-called Polynesian type, i.e.3′-acceptor splice site G->A mutation of intron 5 that resulted in the skipping of exon 6 (called mutation JKΔ6). Conclusion: The present study confirms that the single-tube allele-specific primer/multiplex PCR technique has enabled genomic typing of the Kidd blood group easier and reliable. The frequency and molecular characterization of JK phenotypes for Chinese people in Taiwan have been clearly characterized.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

scholarly journals Preliminary Results of MyCog, a Brief Assessment for the Detection of Cognitive Impairment in Primary Care

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 259-260
Author(s):  
Laura Curtis ◽  
Lauren Opsasnick ◽  
Julia Yoshino Benavente ◽  
Cindy Nowinski ◽  
Rachel O’Conor ◽  
...  
Keyword(s):  
Primary Care ◽  
Cognitive Impairment ◽  
Cognitive Aging ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Self Report ◽  
Card Sorting ◽  
Primary Care Settings

Abstract Early detection of Cognitive impairment (CI) is imperative to identify potentially treatable underlying conditions or provide supportive services when due to progressive conditions such as Alzheimer’s Disease. While primary care settings are ideal for identifying CI, it frequently goes undetected. We developed ‘MyCog’, a brief technology-enabled, 2-step assessment to detect CI and dementia in primary care settings. We piloted MyCog in 80 participants 65 and older recruited from an ongoing cognitive aging study. Cases were identified either by a documented diagnosis of dementia or mild cognitive impairment (MCI) or based on a comprehensive cognitive battery. Administered via an iPad, Step 1 consists of a single self-report item indicating concern about memory or other thinking problems and Step 2 includes two cognitive assessments from the NIH Toolbox: Picture Sequence Memory (PSM) and Dimensional Change Card Sorting (DCCS). 39%(31/80) participants were considered cognitively impaired. Those who expressed concern in Step 1 (n=52, 66%) resulted in a 37% false positive and 3% false negative rate. With the addition of the PSM and DCCS assessments in Step 2, the paradigm demonstrated 91% sensitivity, 75% specificity and an area under the ROC curve (AUC)=0.82. Steps 1 and 2 had an average administration time of <7 minutes. We continue to optimize MyCog by 1) examining additional items for Step 1 to reduce the false positive rate and 2) creating a self-administered version to optimize use in clinical settings. With further validation, MyCog offers a practical, scalable paradigm for the routine detection of cognitive impairment and dementia.

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