Weight, Age and Coefficients of Variation in Renal Solute Excretion

The authors developed a 1H qNMR test procedure for identification and quantification of impurity A present in gabapentin active pharmaceutical ingredient (API) and gabapentin products. The validation studies helped to determine the limit of quantitation and assess linearity, accuracy, repeatability, intermediate precision, specificity, and robustness of the procedure. Spike-and-recovery assays were used to calculate standard deviations, coefficients of variation, confidence intervals, bias, Fisher’s F test, and Student’s t-test for assay results. The obtained statistical values satisfy the acceptance criteria for the validation parameters. The authors compared the results of impurity A quantification in gabapentin APIs and capsules by using the 1H qNMR and HPLC test methods.

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Development and evaluation of an immunoenzymometric assay for the chicken progesterone receptor

Journal of Endocrinology ◽

10.1677/joe.0.1290189 ◽

1991 ◽

Vol 129 (2) ◽

pp. 189-196 ◽

Cited By ~ 5

Author(s):

M. K. Bläuer ◽

P. J. Tuohimaa ◽

P. J. Vilja

Keyword(s):

Monoclonal Antibodies ◽

Small Intestine ◽

Horseradish Peroxidase ◽

Progesterone Receptor ◽

Ligand Binding ◽

Binding Assay ◽

Ligand Binding Assay ◽

Coefficients Of Variation ◽

First Time ◽

Determination Range

ABSTRACT A specific and sensitive immunoenzymometric assay (IEMA) was developed for measuring the quantity of chicken progesterone receptor (PR) in tissue cytosol. The assay uses two monoclonal antibodies to the PR. One is used to capture the PR. The second (labelled with biotin) reacts first with the captured receptor and subsequently with avidin-labelled horseradish peroxidase to provide an enzymatic end-point. The method has a determination range from 0·3 to 60 pmol/l. Intra- and interassay coefficients of variation were 3·7% and 9·0% respectively. The assay can be performed with equal results as a rapid (3 h) or an overnight procedure. The IEMA is convenient, especially for signal measurement and the calculation of results. No ultracentrifugation of samples is needed, since the IEMA can be performed on low-speed cytosol samples. Assay results correlated well (r = 0·927) with those obtained by the conventional ligand-binding assay used in our laboratory. Similar results were obtained with the IEMA and the ligand-binding assay after exposure of cytosol samples to increased temperatures: at 20 °C the PR remained stable for the 4-h period examined, whereas at 37 °C almost complete degradation of the PR was observed in 30 min. Being more than 100 times as sensitive as the ligand-binding assay, the IEMA enabled the quantification of PR for the first time in such tissues as the bursa and small intestine even of immature animals. Journal of Endocrinology (1991) 129, 189–196

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Morphometric Registration of Cytotoxic Changes of Epithelial Cells In Vitro: A Methodological Study

Alternatives to Laboratory Animals ◽

10.1177/026119299001700307 ◽

1990 ◽

Vol 17 (3) ◽

pp. 174-176

Author(s):

Lis Andersen ◽

Dorthe Arenholt-Bindslev

Keyword(s):

Culture System ◽

Optimal Allocation ◽

Volume Density ◽

Cell Culture System ◽

Allocation Of Resources ◽

Methodological Study ◽

Epithelial Cell Culture ◽

Coefficients Of Variation ◽

And Control

Quantification of toxicity-induced cytomorphological effects in an epithelial cell culture system is described. Estimates of volume density and star volume of mitochondria and lysosomes are given. Mean volumes (n = 5) and coefficients of variation of these parameters were equal in experimental (TPA-treatment) and control cultures. An optimal allocation of resources for estimating cytomorphometric parameters would be to increase the number of culture flasks.

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An Assessment of Sampling Methods and Microbiological Hygiene Indicators for Process Verification in Poultry Slaughterhouses

Journal of Food Protection ◽

10.4315/0362-028x-69.1.145 ◽

2006 ◽

Vol 69 (1) ◽

pp. 145-153 ◽

Cited By ~ 20

Author(s):

M. L. HUTCHISON ◽

L. D. WALTERS ◽

G. C. MEAD ◽

M. HOWELL ◽

V. M. ALLEN

Keyword(s):

Storage Time ◽

Sampling Method ◽

Indicator Bacteria ◽

Aerobic Bacteria ◽

Process Verification ◽

Bacterial Indicator ◽

Coefficients Of Variation ◽

Microbiological Testing ◽

The Mean ◽

Poor Relationship

Studies to determine the appropriateness of the use of populations of indicator bacteria on poultry carcasses for process verification were undertaken in commercial slaughterhouses. Samples were collected from neck skin by excision or from whole carcass rinses and were examined for a range of presumptive process hygiene indicator bacteria. Coefficients of variation were calculated for each bacterial indicator and were significantly lower in excised samples, indicating more reproducible bacterial recovery by this sampling method. Total viable counts of aerobic bacteria, Enterobacteriaceae, and Pseudomonas in samples collected by excision had the lowest coefficients of variation when compared with other indicators and were therefore used for further study. The uncertainties associated with the quantification of each bacterial indicator were calculated and were lowest overall for total viable counts of aerobic bacteria. In general, uncertainty was higher for lower bacterial numbers. Results of microbiological testing on pooled excised neck skin samples were not significantly different from the mean of individually analyzed samples. Bacterial numbers increased by 1 log unit when cultures were stored under chilled conditions typical of those used for transporting samples to external laboratories, but the increases were not significant for Pseudomonas and aerobic bacteria when storage time was less than 17 h. Weak relationships were identified between bacterial indicator numbers and duration of processing, although cleanliness of the processing environment diminished visibly during this time. In the plants visited for this study, there was a poor relationship between presumptive bacterial indicator numbers and process hygiene. Consequently, bacterial analyses for process verification purposes may be of limited value.

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Short-Term Reproducibility of MUC5AC Measurement in Human Tear Fluid

Diagnostics ◽

10.3390/diagnostics11010057 ◽

2021 ◽

Vol 11 (1) ◽

pp. 57

Author(s):

Ashley M. Woodward ◽

Michelle Senchyna ◽

Pablo Argüeso

Keyword(s):

Statistical Difference ◽

Tear Film ◽

Therapeutic Strategies ◽

Individual Variability ◽

Tear Fluid ◽

Individual Data ◽

Short Term ◽

Coefficients Of Variation ◽

Novel Therapeutic Strategies ◽

Novel Therapeutic

The assessment of tear fluid components is a common and valuable approach to understanding ocular surface disease and testing the efficacy of novel therapeutic strategies. However, the interpretation and utility of the findings can be limited by changes in the composition of the tear film, particularly in studies requiring repetitive patient sampling. Here, tear samples were collected twice within a one-hour interval to evaluate the short-term reproducibility of an immunoassay aimed to measure the amount of MUC5AC mucin. We found no statistical difference in total protein or MUC5AC content between the two consecutive collections of tear fluid, although the inter-individual variability in each group was high, with coefficients of variation exceeding 30% and 50%, respectively. Scatterplots showed a significant correlation in both protein and MUC5AC following collection within a one-hour interval. These data indicate that, regardless of the high inter-individual variability, repeated collection of tear fluid within an hour interval produces reproducible intra-individual data in terms of MUC5AC mucin content, and suggest that the normal mucin composition of the tear fluid can be re-established within an hour of the initial collection.

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Analytical validation of an automated assay for the measurement of adenosine deaminase (ADA) and its isoenzymes in saliva and a pilot evaluation of their changes in patients with SARS-CoV-2 infection

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2021-0324 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Lorena Franco-Martínez ◽

Fernando Tecles ◽

Alberto Torres-Cantero ◽

Enrique Bernal ◽

Indra San Lázaro ◽

...

Keyword(s):

Adenosine Deaminase ◽

Analytical Validation ◽

Mean Values ◽

Chemical Inactivation ◽

Non Invasive ◽

Automated Assay ◽

Coefficients Of Variation ◽

Recovery Percentage ◽

Triton X ◽

Potential Use

Abstract Objectives The aim of the present study was to validate a commercially available automated assay for the measurement of total adenosine deaminase (tADA) and its isoenzymes (ADA1 and ADA2) in saliva in a fast and accurate way, and evaluate the possible changes of these analytes in individuals with SARS-CoV-2 infection. Methods The validation, in addition to the evaluation of precision and accuracy, included the analysis of the effects of the main procedures that are currently being used for SARS-CoV-2 inactivation in saliva and a pilot study to evaluate the possible changes in salivary tADA and isoenzymes in individuals infected with SARS-CoV-2. Results The automated assay proved to be accurate and precise, with intra- and inter-assay coefficients of variation below 8.2%, linearity under dilution linear regression with R2 close to 1, and recovery percentage between 80 and 120% in all cases. This assay was affected when the sample is treated with heat or SDS for virus inactivation but tolerated Triton X-100 and NP-40. Individuals with SARS-CoV-2 infection (n=71) and who recovered from infection (n=11) had higher mean values of activity of tADA and its isoenzymes than healthy individuals (n=35). Conclusions tADA and its isoenzymes ADA1 and ADA2 can be measured accurately and precisely in saliva samples in a rapid, economical, and reproducible way and can be analyzed after chemical inactivation with Triton X-100 and NP-40. Besides, the changes observed in tADA and isoenzymes in individuals with COVID-19 open the possibility of their potential use as non-invasive biomarkers in this disease.

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Evaluation of some sunflower genotypes for agronomic traits and oil quality

Helia ◽

10.1515/helia-2020-0027 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Khaled Mohamed Aboelkassem ◽

Asmaa Abd-EL-Halime Ahmed ◽

Mohamed Ali Abdelsatar

Keyword(s):

Fatty Acids ◽

Seed Yield ◽

Seed Weight ◽

Unsaturated Fatty Acids ◽

Agronomic Traits ◽

Oil Quality ◽

Research Station ◽

Head Diameter ◽

Coefficients Of Variation ◽

100 Seed Weight

Abstract The present investigation was carried out to evaluate agronomic performance and oil quality of seven sunflower genotypes at Shandaweel Research Station, Agricultural Research Center, Sohag, Egypt during 2018 and 2019 summer seasons. These genetic materials were sown in a randomized complete block design having three replications. Significant genetic variations among evaluated sunflower genotypes for agronomic traits and oil quality were observed. The superior sunflower genotypes were Line 120 for seed yield per hectare (3102.38 kg), Sakha 53 for seed oil content (44.63 %) and Line 125 for oil quality where it contained the highest proportion of unsaturated fatty acids (89.20 %). The phenotypic coefficients of variation were slightly higher than genotypic coefficients of variation for all studied traits. High heritability (exceeded 60%) and genetic advance as percent of mean (ranged from medium to high, exceeded 10%) was observed for most studied traits. Seed yield per plant positively correlated with plant height, stem diameter, head diameter, and 100-seed weight and most chemical traits at phenotypic and genotypic levels. Maximum phenotypic direct effects on seed yield per plant were observed for 100-seed weight, head diameter and total unsaturated fatty acids. While, the highest genotypic direct effect on seed yield per plant was observed for head diameter. Hence, most studied traits could be employed as selection criteria for improving evaluated sunflower genotypes.

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Comparing Mutational Variabilities

Genetics ◽

10.1093/genetics/143.3.1467 ◽

1996 ◽

Vol 143 (3) ◽

pp. 1467-1483 ◽

Cited By ~ 17

Author(s):

David Houle ◽

Bob Morikawa ◽

Michael Lynch

Keyword(s):

Life History ◽

Morphological Traits ◽

Life History Traits ◽

Genetic Variance ◽

Balance Model ◽

Phenotypic Traits ◽

Infinite Population ◽

Persistence Time ◽

Coefficients Of Variation ◽

Balance Hypothesis

Abstract We have reviewed the available data on VM, the amount of genetic variation in phenotypic traits produced each generation by mutation. We use these data to make several qualitative tests of the mutation-selection balance hypothesis for the maintenance of genetic variance (MSB). To compare VM values, we use three dimensionless quantities: mutational heritability, the mutational coefficient of variation, CVM; and the ratio of the standing genetic variance to VM, VG/VM. Since genetic coefficients of variation for life history traits are larger than those for morphological traits, we predict that under MSB, life history traits should also have larger CVM. This is confirmed; life history traits have a median CVM value more than six times higher than that for morphological traits. VG/VM approximates the persistence time of mutations under MSB in an infinite population. In order for MSB to hold, VG/VM must be small, substantially less than 1000, and life history traits should have smaller values than morphological traits. VG/VM averages about 50 generations for life history traits and 100 generations for morphological traits. These observations are all consistent with the predictions of a mutation-selection balance model.

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Percentile transformation and recalibration functions allow harmonization of thyroid-stimulating hormone (TSH) immunoassay results

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2019-1167 ◽

2020 ◽

Vol 58 (10) ◽

pp. 1663-1672 ◽

Cited By ~ 3

Author(s):

Andrea Padoan ◽

Aldo Clerico ◽

Martina Zaninotto ◽

Tommaso Trenti ◽

Renato Tozzoli ◽

...

Keyword(s):

Robust Regression ◽

Reference Intervals ◽

Thyroid Stimulating Hormone ◽

Validation Dataset ◽

New Approach ◽

Coefficients Of Variation ◽

Significant Difference ◽

Before And After ◽

Roche Diagnostics ◽

Stimulating Hormone

AbstractBackgroundThe comparability of thyroid-stimulating hormone (TSH) results cannot be easily obtained using SI-traceable reference measurement procedures (RPMs) or reference materials, whilst harmonization is more feasible. The aim of this study was to identify and validate a new approach for the harmonization of TSH results.MethodsPercentile normalization was applied to 125,419 TSH results, obtained from seven laboratories using three immunoassays (Access 3rd IS Thyrotropin, Beckman Coulter Diagnostics; Architect System, Abbott Diagnostics and Elecsys, Roche Diagnostics). Recalibration equations (RCAL) were derived by robust regressions using bootstrapped distribution. Two datasets, the first of 119 EQAs, the second of 610, 638 and 639 results from Access, Architect and Elecsys TSH results, respectively, were used to validate RCAL. A dataset of 142,821 TSH values was used to derive reference intervals (RIs) after applying RCAL.ResultsAccess, Abbott and Elecsys TSH distributions were significantly different (p < 0.001). RCAL intercepts and slopes were −0.003 and 0.984 for Access, 0.032 and 1.041 for Architect, −0.031 and 1.003 for Elecsys, respectively. Validation using EQAs showed that before and after RCAL, the coefficients of variation (CVs) or among-assay results decreased from 10.72% to 8.16%. The second validation dataset was used to test RCALs. The median of between-assay differences ranged from −0.0053 to 0.1955 mIU/L of TSH. Elecsys recalibrated to Access (and vice-versa) showed non-significant difference. TSH RI after RCAL resulted in 0.37–5.11 mIU/L overall, 0.49–4.96 mIU/L for females and 0.40–4.92 mIU/L for males. A significant difference across age classes was identified.ConclusionsPercentile normalization and robust regression are valuable tools for deriving RCALs and harmonizing TSH values.

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Improved thin-layer chromatography of disaturated phosphatidylcholine in amniotic fluid.

Clinical Chemistry ◽

10.1093/clinchem/27.2.239 ◽

1981 ◽

Vol 27 (2) ◽

pp. 239-242 ◽

Cited By ~ 15

Author(s):

M Y Tsai ◽

M Cain ◽

M W Josephson

Keyword(s):

Respiratory Distress ◽

Thin Layer ◽

Amniotic Fluid ◽

Thin Layer Chromatography ◽

Fetal Lung ◽

Dipalmitoyl Phosphatidylcholine ◽

Fetal Lung Maturity ◽

Coefficients Of Variation ◽

Layer Chromatography ◽

Lung Maturity

Abstract We describe an indirect test of fetal lung maturity: the quantitation of disaturated phosphatidylcholine in amniotic fluid. The lipids in samples of amniotic fluid from 172 patients were reacted with osmium tetroxide, and disaturated phosphatidylcholine was then isolated by thin-layer chromatography. Interfering substances were retained by a pre-adsorbent layer. The charred disaturated phosphatidylcholine, quantitated by densitometry, was compared to standard dipalmitoyl phosphatidylcholine. Both within-run and between-run coefficients of variation were about 10%. Blood and meconium do not interfere. Six infants developed respiratory distress when disaturated phosphatidylcholine concentrations of amniotic fluid drawn within 72 h of delivery were less than 5.5 mg/L. A concurrently determined lecithin/sphingomyelin ratio falsely predicted lung maturity in one of these. In seven other samples for which lecithin/sphingomyelin ratios suggested lung immaturity but disaturated phosphatidyl-choline predicted maturity, none of the infants developed respiratory distress. In normal pregnancies, measurement of disaturated phosphatidylcholine in amniotic fluid appears to be a better predictor of fetal lung maturity than is measurement of the lecithin/sphingomyelin ratio. Further studies are needed to determine if this analysis is a better predictor in diabetic pregnancies.

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