Spurious Results of Digoxin Radioimmunoassay

1984 ◽  
Vol 310 (11) ◽  
pp. 725-725 ◽  
Keyword(s):  
Spurious Results ◽  
Digoxin Radioimmunoassay

scholarly journals Preanalytical Phase in Haematology

2008 ◽  
Vol 27 (3) ◽  
pp. 348-353 ◽  
Author(s):  
Giuseppe Banfi ◽  
L. Germagnoli
Keyword(s):  
Clinical Decision ◽  
Blood Parasites ◽  
Haematological Parameters ◽  
Pathological Conditions ◽  
Blood Drawing ◽  
Preanalytical Phase ◽  
Valid Data ◽  
Spurious Results ◽  
Instrumental Precision ◽  
Hematological Tests

Preanalytical Phase in Haematology The preanalytical phase is particularly important in haematology, where counts of particles and cells are performed in whole anticoagulated blood. The correct use and concentration of anticoagulant is mandatory to avoid spurious results, which can influence clinical decision. EDTA is the anticoagulant of choice, but it has some limits, especially for preserving stability and shape of platelets. Stability of haematological parameters is high, with the exception of leukocytes and reticulocytes. However, stability (and instrumental precision) should be evaluated together with biological variability and individuality index of various haematological parameters. Hematological tests are also influenced and interfered by high amounts of lipids and chylomicrons. The mixing procedure of the tubes after blood drawing and before analysis is also crucial for obtaining correct and valid data. There are some examples of interferences on automated haematological analysers which are used for diagnosing and screening pathological conditions. Cryoglobulins and erythrocytes parasites can induce spurious results of WBC, RBC and PLT, but the repeatability of these interferences could be used for alerting the pathologist and could reveal the presence of pathological proteins or blood parasites. New parameters have been proposed by modern haematological analysers, directly defined or calculated from traditional measures, but the clinical impact of these new parameters is often dependent on preanalytical variables.

scholarly journals A phylogenetic transform enhances analysis of compositional microbiota data

2016 ◽  
Author(s):  
Justin D Silverman ◽  
Alex Washburne ◽  
Sayan Mukherjee ◽  
Lawrence A David
Keyword(s):  
Microbial Communities ◽  
Relative Abundance ◽  
Dominant Role ◽  
Phylogenetic Information ◽  
Abundance Data ◽  
Sequencing Technologies ◽  
Environmental Selection ◽  
Health And Disease ◽  
High Throughput Dna Sequencing ◽  
Spurious Results

ABSTRACTHigh-throughput DNA sequencing technologies have revolutionized the study of microbial communities (microbiota) and have revealed their importance in both human health and disease. However, due to technical limitations, data from microbiota surveys reflect the relative abundance of bacterial taxa and not their absolute levels. It is well known that applying common statistical methods, such as correlation or hypothesis testing, to relative abundance data can lead to spurious results. Here, we introduce the PhILR transform, a data transform that utilizes microbial phylogenetic information. This transform enables off-the-shelf statistical tools to be applied to microbiota surveys free from artifacts usually associated with analysis of relative abundance data. Using environmental and human-associated microbial community datasets as benchmarks, we find that the PhILR transform significantly improves the performance of distance-based and machine learning-based statistics, boosting the accuracy of widely used algorithms on reference benchmarks by 90%. Because the PhILR transform relies on bacterial phylogenies, statistics applied in the PhILR coordinate system are also framed within an evolutionary perspective. Regression on PhILR transformed human microbiota data identified evolutionarily neighboring bacterial clades that may have differentiated to adapt to distinct body sites. Variance statistics showed that the degree of covariation of bacterial clades across human body sites tended to increase with phylogenetic relatedness between clades. These findings support the hypothesis that environmental selection, not competition between bacteria, plays a dominant role in structuring human-associated microbial communities.

scholarly journals Multiplicity Eludes Peer Review: The Case of COVID-19 Research

2021 ◽  
Vol 18 (17) ◽  
pp. 9304
Author(s):  
Oliver Gutiérrez-Hernández ◽  
Luis Ventura García
Keyword(s):  
Peer Review ◽  
Observational Studies ◽  
Social Impact ◽  
Type I Error ◽  
Peer Review Process ◽  
Type I ◽  
Strongly Correlated ◽  
P Values ◽  
False Discoveries ◽  
Spurious Results

Multiplicity arises when data analysis involves multiple simultaneous inferences, increasing the chance of spurious findings. It is a widespread problem frequently ignored by researchers. In this paper, we perform an exploratory analysis of the Web of Science database for COVID-19 observational studies. We examined 100 top-cited COVID-19 peer-reviewed articles based on p-values, including up to 7100 simultaneous tests, with 50% including >34 tests, and 20% > 100 tests. We found that the larger the number of tests performed, the larger the number of significant results (r = 0.87, p < 10−6). The number of p-values in the abstracts was not related to the number of p-values in the papers. However, the highly significant results (p < 0.001) in the abstracts were strongly correlated (r = 0.61, p < 10−6) with the number of p < 0.001 significances in the papers. Furthermore, the abstracts included a higher proportion of significant results (0.91 vs. 0.50), and 80% reported only significant results. Only one reviewed paper addressed multiplicity-induced type I error inflation, pointing to potentially spurious results bypassing the peer-review process. We conclude the need to pay special attention to the increased chance of false discoveries in observational studies, including non-replicated striking discoveries with a potentially large social impact. We propose some easy-to-implement measures to assess and limit the effects of multiplicity.

On standards provided with digoxin radioimmunoassay kits.

1983 ◽  
Vol 29 (4) ◽  
pp. 734-735 ◽  
Author(s):  
L Molin ◽  
B Bergdahl
Keyword(s):  
Digoxin Radioimmunoassay

Reduced variation of tracer binding in digoxin radioimmunoassay by use of (125I)-labeled tyrosine-methyl-ester derivative: relation of thyroxine concentration to binding.

1976 ◽  
Vol 22 (10) ◽  
pp. 1732-1734 ◽  
Author(s):  
B H Kroening ◽  
M Weintraub
Keyword(s):  
Methyl Ester ◽  
Binding Proteins ◽  
Serum Samples ◽  
Methyl Ester Derivative ◽  
Ester Derivative ◽  
Free Serum ◽  
Digoxin Radioimmunoassay

Abstract Between-sample variation in tracer binding in the 125I-labeled digoxin radioimmunoassay was investigated with two tracers, 3-O-succinyl-digoxigenin-[125I]-labeled tyrosine and [125I]-labeled tyrosine-methyl-ester-digoxin. Digoxin-free serum samples having various concentrations of thyroxine were assayed with both tracers. The percentage of tracer bound when the samples were assayed with the first-mentioned tracer was increased significantly for the low thyroxine groups when compared to the normal (P less than 0.001) or the high thyroxine groups (P less than 0.05). Little difference existed when the latter tracer was used. There was variation in tracer binding when serum from dogs dosed with thyrotropin was assayed with the first tracer, but there was little variation with the second. Tracer binding may be influenced by thyroxine-binding proteins. Variation in tracer binding appears to be reduced when [125I]-labeled tyrosine-methyl-ester-digoxin is used.

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