scholarly journals Evaluation of Kinetics and Single-Read Enzyme-Linked Immunoassays for Detection of Toxoplasma Gondii Antibodies in Sheep

2002 ◽  
Vol 14 (3) ◽  
pp. 225-230 ◽  
Author(s):  
Stephen R. Werre ◽  
Richard H. Jacobson ◽  
Dwight D. Bowman ◽  
Jitender P. Dubey ◽  
Hussni O. Mohammed

A kinetics enzyme-linked immunosorbent assay (ELISA) and a single-read ELISA for the detection of ovine anti- Toxoplasma gondii IgG were developed and optimized. During the kinetics assay, 3 optical densities were obtained for each serum sample at intervals of 45 seconds, and the results were presented as average slopes (replicates of 2) of the reaction rate between bound enzyme and substrate solution. The kinetics ELISA was stopped 5 minutes after dispensing the substrate to constitute the single-read ELISA, and the results were presented as average optical densities for duplicates of each sample. Performance of the assays was evaluated using the modified agglutination test (MAT) as the “gold standard.” There was a high level of agreement between both ELISAs and the MAT, as measured by Pearson correlation coefficients, kappa statistics, and the area under the receiver operating characteristics curves. The single-read ELISA was as accurate as the kinetics ELISA, with a sensitivity of 89% and a specificity of 96%.

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 9 ◽  
Author(s):  
Shuai Wang ◽  
Zhijun Yao ◽  
Lingjuan Li ◽  
Yaoqian Pan ◽  
Pengju Li ◽  
...  

Rabbits (Oryctolagus cuniculus) are frequently reared for meat production in China. The aim of this study was to assess the seroprevalence of Toxoplasma gondii and Encephalitozoon cuniculi, and risk factors of infection in domestic rabbits raised in Henan province, central China. 1,213 serum samples of domestic rabbits were collected and tested for anti-T. gondii and anti-E. cuniculi antibodies using a modified agglutination test (MAT) and an enzyme-linked immunosorbent assay (ELISA), respectively. The serum positive rates of T. gondii and E. cuniculi were 128/1,213 (10.55%) and 235/1,213 (19.37%), respectively. Co-infection of T. gondii and E. cuniculi was demonstrated in 84 specimens; 44 rabbits were seropositive for T. gondii alone, while 151 rabbits were seropositive for E. cuniculi alone. The main risk factors simultaneously associated with T. gondii and E. cuniculi infection were the age of the rabbit, the type of food, and the rabbit rearing system. Serum positive rates of T. gondii and E. cuniculi among domestic rabbits were high, indicating the possibility of public health issues.


1996 ◽  
Vol 23 (2) ◽  
pp. 197 ◽  
Author(s):  
L Allen ◽  
R Engeman ◽  
H Krupa

Three methods of assessing relative abundance of wild canids were evaluated on a population of dingoes, Canis lupus dingo (Corbett), on a cattle station in south-westem Queensland. The tested indices relied on measurements of activity based on spoor. Two of the techniques attracted the target species to tracking stations through the use of a novel (fatty acid scent) or food-based (buried meat) attractant. The third index (activity) measured the number of dingo tracks crossing tracking stations placed at 1-km intervals along a road transect. All three indices had a high level of agreement for detecting differences in relative abundance, with correlation coefficients exceeding 0.85. When the stations were analysed in 1-km segments, the activity index proved the most sensitive, producing proportionally more positive responses than either of the other two indices irrespective of whether the tracking stations were assessed at 1-, 2-, 3- or 4-day intervals. Inconsistencies between indices existed, with the derived abundance indices not showing the anticipated reduction following population reduction. The effect of season and the interaction between dingo activity and index methodology are discussed.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jumat Salimon ◽  
Talal A. Omar ◽  
Nadia Salih

Two different procedures for the methylation of fatty acids (FAs) andtransfatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination ofcis/transFAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higherRvalues, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of richcis/transUFA samples.


Author(s):  
Xiaolin C. Hu ◽  
Edward L. Meyen

This study investigates the preferences of instructors and students for design and pedagogy features of online instruction at the post-secondary level. Participants included 60 instructors and 200 students at a comprehensive research university. Correlation coefficients of .95 on the design item rankings and .87 on the pedagogy item rankings were found between instructors and students. An independent sample T-test was conducted, resulting in a finding of significant difference between the preferences of instructors and students on 19 of 63 features. Additional findings included the high level of agreement on design and pedagogy features among all students as a group and subgroups (e.g., students earning regular university credit and those pursuing professional development goals.) An interesting finding was the concurrence in the low preferences by instructors and students. Both groups rated low those features pertaining to social networking and collaboration.


Author(s):  
Jai Jai Shiva Shankar ◽  
Gavin Langlands ◽  
Steve Doucette ◽  
Stephen Phillips

AbstractBackground: Computed tomography perfusion (CTP) is increasingly being used in the setting of acute ischemic stroke (AIS). The aim of the current study was to compare the prognostic utility of, and inter-observer variation between, baseline appearances on non-contrast CT (using Alberta Stroke Program Early CT score(ASPECTS)) and on CTP for predicting final infarct volume. We also assessed impact of training on interpretation of these images. Methods: Retrospectively, plain head computed tomography (CT) and CTP images at presentation and CT or diffusion imaging on follow up of patients with AIS were analyzed. The lesion volume on different CTP parameters was then correlated with the final infarct volume. This analysis was done by a Neuroradiologist, a stroke Neurologist and a medical student. Kappa statistics and Intra-class correlation coefficients were used for agreement between readers. Pearson correlation coefficients were used.Results: Thirty eight patients with AIS met all inclusion criteria. There was very good agreement among all readers for the CTP parameters. There was only fair agreement for ASPECT score. Correlation coefficient (r-square) between CTP parameters and final infarct volume showed that cerebral blood volume was the best parameter to predict the final infarct volume followed by cerebral blood flow and time to peak. The best reader to predict the final infarct volume on the initial CT perfusion study was the neuroradiologist followed by medical student and stroke neurologist. Conclusions: Cerebral blood volume defect correlated the best with the final infarct volume. There was a very good inter-observer agreement for all the CTP maps in predicting the final infarct volume despite the wide variation in the experience of the readers.


Author(s):  
Seon Hee Lim ◽  
Nayoung Kim ◽  
Sung Eun Kim ◽  
Gwang Ho Baik ◽  
Ju Yup Lee ◽  
...  

Background/Aims: In serological tests for <i>Helicobacter pylori</i> (<i>H. pylori</i>), an enzyme-linked immunosorbent assay (GENEDIA<sup>®</sup>) and a solid-phase, two-step chemiluminescent enzyme immunoassay (IMMULITE<sup>®</sup>), which are easy to perform, inexpensive, and widely available, are commonly used. However, local validation of the test performance of IMMULITE<sup>®</sup> is required. This study aimed to examine the performance of IMMULITE<sup>®</sup> in comparison with that of GENEDIA<sup>®</sup> in a Korean health checkup population.Materials and Methods: The sera of 300 subjects among those who underwent health checkup were analyzed using IMMULITE<sup>®</sup>, and results were compared with those of GENEDIA<sup>®</sup>. The two serological tests were compared for their ability to predict atrophic gastritis (AG) or intestinal metaplasia (IM) on endoscopy.Results: We found significant correlation (Pearson correlation coefficient=0.903, <i>P</i><0.0001) and an almost perfect agreement (Cohen’s Kappa coefficient=0.987, <i>P</i><0.0001) between the results of GENEDIA<sup>®</sup> and IMMULITE<sup>®</sup>. The area under the receiver operating characteristics curve (AUC) for AG using GENEDIA<sup>®</sup> and IMMULITE<sup>®</sup> were 0.590 and 0.604, respectively, and showed no statistically significant difference in predictive ability for AG (<i>Z</i>-statistics=-0.517, <i>P</i>=0.605). The AUC for IM by GENEDIA<sup>®</sup> and IMMULITE<sup>®</sup> were 0.578 and 0.593, respectively, with no statistically significant difference in predictive ability for IM between the two values (<i>Z</i>-statistics=-0.398, <i>P</i>=0.691).Conclusions: No statistically significant difference in diagnostic value for <i>H. pylori</i> infection was found between GENEDIA<sup>®</sup> and IMMULITE<sup>®</sup>.


Author(s):  
Xiaolin C. Hu ◽  
Edward L. Meyen

This study investigates the preferences of instructors and students for design and pedagogy features of online instruction at the post-secondary level. Participants included 60 instructors and 200 students at a comprehensive research university. Correlation coefficients of .95 on the design item rankings and .87 on the pedagogy item rankings were found between instructors and students. An independent sample T-test was conducted, resulting in a finding of significant difference between the preferences of instructors and students on 19 of 63 features. Additional findings included the high level of agreement on design and pedagogy features among all students as a group and subgroups (e.g., students earning regular university credit and those pursuing professional development goals.) An interesting finding was the concurrence in the low preferences by instructors and students. Both groups rated low those features pertaining to social networking and collaboration.


2019 ◽  
Vol 10 (3) ◽  
pp. 469 ◽  
Author(s):  
Ali Akbar Khomeijani Farahani ◽  
Hassti Gholam-Shahbazi

This study was an attempt to explore the role of emotional intelligence on the whole and its components particularly problem solving in EFL learners’ listening comprehension performance in the IELTS tests. For this purpose, a total of 39 advanced learners homogenized according to Oxford Placement Test took part in this study. Participants completed the IELTS listening tests and were asked to fill out the Bar-On emotional intelligence questionnaire. The obtained quantitative data were analyzed using Pearson correlation coefficients. Results indicated a non-significant correlation between the whole EI scores and listening performance of learners. There were, however, a significant relationship between problem solving and EI. The social responsibility component of EI was also found to have a significant relationship with listening. The findings are discussed with regard to the role of the IELTS test as a standardized test and the high level of learners. Implications and suggestions for further research are presented.


2012 ◽  
Vol 19 (10) ◽  
pp. 1609-1617 ◽  
Author(s):  
Brian D. Plikaytis ◽  
Maria Stella ◽  
Giuseppe Boccadifuoco ◽  
Lisa M. DeTora ◽  
Mauro Agnusdei ◽  
...  

ABSTRACTThe meningococcal antigen typing system (MATS) sandwich enzyme-linked immunosorbent assay (ELISA) was designed to measure the immunologic cross-reactivity and quantity of antigens in target strains of a pathogen. It was first used to measure the factor H-binding protein (fHbp), neisserial adhesin A (NadA), and neisserial heparin-binding antigen (NHBA) content of serogroup B meningococcal (MenB) isolates relative to a reference strain, or “relative potency” (RP). With the PorA genotype, the RPs were then used to assess strain coverage by 4CMenB, a multicomponent MenB vaccine. In preliminary studies, MATS accurately predicted killing in the serum bactericidal assay using human complement, an accepted correlate of protection for meningococcal vaccines. A study across seven laboratories assessed the reproducibility of RPs for fHbp, NadA, and NHBA and established qualification parameters for new laboratories. RPs were determined in replicate for 17 MenB reference strains at laboratories A to G. The reproducibility of RPs among laboratories and against consensus values across laboratories was evaluated using a mixed-model analysis of variance. Interlaboratory agreement was very good; the Pearson correlation coefficients, coefficients of accuracy, and concordance correlation coefficients exceeded 99%. The summary measures of reproducibility, expressed as between-laboratory coefficients of variation, were 7.85% (fHbp), 16.51% (NadA), and 12.60% (NHBA). The overall within-laboratory measures of variation adjusted for strain and laboratory were 19.8% (fHbp), 28.8% (NHBA), and 38.3% (NadA). The MATS ELISA was successfully transferred to six laboratories, and a further laboratory was successfully qualified.


2019 ◽  
Vol 12 ◽  
pp. 175628481982823 ◽  
Author(s):  
Cátia Rocha ◽  
Joana Afonso ◽  
Paula Lago ◽  
Bruno Arroja ◽  
Ana I. Vieira ◽  
...  

Background: The loss of response to adalimumab (ADL) has been related to low serum concentrations at trough. Currently, most methods commercially available for the quantification of ADL are enzyme-linked immunosorbent assay (ELISA) based, with a turnaround time of approximately 8 h, delaying the target dosage adjustment to the subsequent infusion. In this study, we aimed to evaluate the performance of the newly available rapid-test ADL quantification assay by comparing it with three established ELISA methods, using spiked samples and a set of clinical samples. Methods: Spiked samples from control donors and 120 serum samples from inflammatory bowel disease (IBD) patients undergoing ADL therapy were quantified using lateral flow Quantum Blue® Adalimumab and, the ELISA formats from Immundiagnostik, R-Biopharm and an in-house assay. Results: The rapid-test assay had intraclass correlation coefficients of 0.590, 0.864 and 0.761 when comparing with the Immundiagnostik, R-Biopharm and in-house assays, respectively. For the five therapeutic windows, the accuracy was high: ADL rapid test compared with the Immundiagnostik (58–88%); R-Biopharm, 68–89%; and in house, 60–88%; and kappa statistics revealed 0.492–0.602, 0.531–0.659 and 0.545–0.682, respectively. Conclusions: The Quantum Blue® Adalimumab assay can replace the commonly used ELISA-based ADL quantification kits and it is a reliable alternative to these methods. This rapid-test assay enables the quantitative determination of ADL serum trough level in only 15 min. The developed assay allows measurement of ADL over a wide range. Hence, it represents a valuable tool for the clinician to assess the ADL trough level.


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