Extraction of meaningful biological information from the vast array of data that metabolomics analyses generate is a major challenge in the field. A variety of computational and visual tools that ...help to identify changes in metabolic pathways have been proposed including functional analysis and pathway analysis. Meta-analysis of metabolomic data has emerged as a powerful source of information. In this work, the applicability of the Mantel's test for the correlation of functional results from metabolic pathway analysis is shown using experimental and simulated data sets as evaluation examples. The statistical significance of the correlation coefficient can be assessed by permutation testing requiring practically no computation time. The use of the Mantel's test can assist the critical comparison of different phenotypes, studies, methods, platforms, or data preprocessing strategies, as well as help to identify inconsistencies between metabolomic study outcomes, making this algorithm attractive for data interpretation and meta-analysis on a routine basis.
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•The Mantel's test enables the correlation of metabolic pathway analysis results.•The test can be used for the critical evaluation of different metabolomic studies.•The test is well established, and it requires practically no computation time.
A major problem for the isolation and transplantation of hepatocytes is the lack of resources for obtaining viable hepatocytes. Improving this situation would enhance hepatic cell transplantation ...programs. Our objective was to evaluate the influence of the preservation solutions used during organ retrieval on the quality of hepatocytes isolated from liver tissue. We compared the results of the collagenase perfusion technique for isolation of hepatocytes in human livers flushed with University of Wisconsin (UW) and Celsior preservation solutions. Yield (number of viable cells per gram of tissue), cellular viability, efficiency of cells to attach to culture plates and form a monolayer, and drug metabolizing competence of the hepatocytes were measured. Successful isolation was achieved in 63% of the procedures using the UW solution and 100% of the procedures using the Celsior solution. In the UW group, significantly lower cell viability (38 ± 41% vs. 79 ± 14%, p < 0.05), yield of cells (4.0 ± 5.2 × 106 vs. 8.2 ± 5.6 × 106 cells/g, p < 0.05), and protein content at 24 h of culture (0.6 ± 0.6 vs. 1.2 ± 0.3 mg protein per plate, p < 0.05) than in Celsior solution were found. However, similar values of P450 activities were found in both groups. The more successful isolation, better yield, and higher cell viability obtained from human liver grafts preserved in Celsior solution, in comparison to UW solution, suggest Celsior solution as the most appropriate for preserving cadaveric hepatic tissue to be used for hepatocyte harvesting.
Chromaffin cells in culture show high neuropathy target esterase (NTE) activity. It is well known that inhibition and specific modification of NTE by some organophosphorus (OPs) compounds induces a ...neurodegenerative neuropathy. It has been suggested that NTE is responsible for phosphatidylcholine homeostasis, although its role in neuropathy induction remains unclear. The cDNA of human NTE (4.4
kbp) was inserted into an adenoviral vector. Bovine chromaffin cells cultured at 50,000 cells/well were incubated with the vector for 2
h and after removing the volume of infection, cells were maintained in the incubator. After 24
h, NTE activity was 6.8
±
0.5
mU/10
6 cells in untreated cells and 14.8
±
1.5
mU/10
6 cells, 19.3
±
2.9
mU/10
6 cells, 24.8
±
0.9
mU/10
6 cells and 30.9
±
1.0
mU/10
6 cells in cells incubated with 2, 4, 8 and 16
μl of vector, respectively. After 60
min of inhibition with mipafox increased concentrations, the calculated I
50 (60
min) values were 5.5, 6.2 and 6.6
μM for cells infected with 0, 2 and 10
μl of vector preparation. We confirm that the adenoviral vector containing the human NTE gene is active in bovine chromaffin cells in culture and that the NTE activity expressed by the vector shows the same inhibition pattern by the neuropathic OP mipafox as the NTE activity of bovine chromaffin cells and cells remained viable after the high NTE activity expression.
Apoptosis may be a major event in chemical-induced injury, and therefore the detection of apoptotic effects when developing new drugs is highly relevant in screening for pharmacotoxicological risk ...assessment. However, as apoptosis in vitro normally degenerates to secondary necrosis, it is possible that it is underestimated, unless sensitive and specific parameters are used. In this present study we have evaluated the usefulness of a set of markers associated with the pivotal steps in the execution phase of apoptosis, in order to detect apoptotic compounds in hepatocytes before significant necrosis takes place. The markers selected include several biochemical parameters (downregulation of the antiapoptotic bclX(L) gene, caspase-3 activation, and cytochrome C release from mitochondria), and flow cytometry determinations (analysis of the size of the nuclei, chromatin complexity, and DNA integrity). The effects of several well-known model apoptotic toxicants (galactosamine, tertiary-butyl-hydroperoxide, etoposide, campothecine, and curcumin) were analyzed in hepatocytes. The aim was to identify early markers of apoptosis using known inducers of apoptosis in hepatocytes, as this battery of markers is designed to identify compounds triggering apoptosis in hepatocytes prior to necrosis. Concentrations of the compounds, as low as possible in order to keep 90% of hepatocyte viability, were selected according to their intracellular lactate dehydrogenase (LDH) leakage, which is well known as an indicator of cell membrane integrity and cell viability. The results demonstrated that (1) the apoptotic effect of 4 out of 5 compounds could be detected in low concentrations of the drugs long before cell necrosis (tertiary-butyl-hydroperoxide-induced apoptosis was only detected at concentrations causing concomitant necrosis) and (2) among the markers evaluated, caspase 3 activation and nucleus and DNA analysis by flow cytometry were used to fulfil the compromise between reliability, sensitivity, and ease of performance, which are critical issues when screening for an apoptotic effect of newly developed drugs.
Provider: - Institution: - Data provided by Europeana Collections- nociones básicas acerca del género botánico/especie y su cultivo, englobadas en el programa de la asignatura de "Cultivos de ...Montaña" (4425)- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- introducción a la asignatura de Fitotecnia, justificación y explicación de la estructura y contenido de la asignatura- All metadata ...published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- Principales aspectos del cultivo de especies interesantes del género Lavándula- All metadata published by Europeana are available ...free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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