Search results for "BF"
showing 10 items of 1614 documents
El Análisis Factorial Exploratorio de los Ítems: una guía práctica, revisada y actualizada
2014
El Análisis Factorial Exploratorio es una de las técnicas más usadas en el desarrollo, validación y adaptación de instrumentos de medida psicológicos. Su uso se extendió durante los años 60 y ha ido creciendo de forma exponencial al ritmo que el avance de la informática ha permitido. Los criterios empleados en su uso, como es natural, también han evolucionado. Pero los investigadores interesados en asuntos sustantivos que utilizan rutinariamente esta técnica permanecen en muchos casos ignorantes de todo ello. En las últimas décadas numerosos trabajos han denunciado esta situación. La necesidad de actualizar los criterios clásicos para incorporar aquellos más adecuados es una necesidad urgen…
Diagnostic utility of new short versions of AUDIT to detect binge drinking in undergraduate students
2021
ABSTRACT This study examines the usefulness of two AUDIT adaptations with a sample of 907 undergraduate alcohol users. On the one hand, it includes the AR2i that encompasses revised A2r and A3r consumption items, and on the other hand—in addition to the two former items—the inclusion of items 4, 8, and 9, which evaluate consequences. The results indicate that both adaptations identify BD more precisely than the traditional scales (AUDIT and AUDIT-C), but the usefulness of each will depend on the clinical purpose they are given. In environments where time is a key factor in detecting high-risk consumption it will be more appropriate to use AR2i, which evaluates the pattern of con…
Inducible ASABF-Type Antimicrobial Peptide from the Sponge Suberites domuncula: Microbicidal and Hemolytic Activity in Vitro and Toxic Effect on Moll…
2011
Since sponges, as typical filter-feeders, are exposed to a high load of attacking prokaryotic and eukaryotic organisms, they are armed with a wide arsenal of antimicrobial/cytostatic low-molecular-weight, non-proteinaceous bioactive compounds. Here we present the first sponge agent belonging to the group of ASABF-type antimicrobial peptides. The ASABF gene was identified and cloned from the demospongeSuberites domuncula. The mature peptide, with a length of 64 aa residues has a predicted pI of 9.24, and comprises the characteristic CSαβ structural motif. Consequently, the S. domuncula ASABF shares high similarity with the nematode ASABFs ; it is distantly related to the defensins. The recom…
Isopetasin and S-isopetasin as novel P-glycoprotein inhibitors against multidrug-resistant cancer cells
2019
Abstract Background A major problem of cancer treatment is the development of multidrug resistance (MDR) to chemotherapy. MDR is caused by different mechanisms such as the expression of the ABC-transporters P-glycoprotein (P-gp, MDR1, ABCB1) and breast cancer resistance protein (BCRP, ABCG2). These transporters efflux xenobiotic toxins, including chemotherapeutics, and they were found to be overexpressed in different cancer types. Purpose Identification of novel molecules that overcome MDR by targeting ABC-transporters. Methods Resazurin reduction assay was used for cytotoxicity test. AutoDock 4.2. was used for molecular docking. The function of P-gp and BCRP was tested using a doxorubicin …
Collateral sensitivity of drug-resistant ABCB5- and mutation-activated EGFR overexpressing cells towards resveratrol due to modulation of SIRT1 expre…
2019
Abstract Background In the drug discovery field, natural products deemed a precious source of novel lead compounds. They have the ability to bypass or overcome multidrug resistance (MDR) in cancer cells. Purpose In this study, the natural polyphenolic stilbene resveratrol (RES) has been studied for its cytotoxic activity toward MDR cancer cells. Methods Resazurin assay was used to investigate the cytotoxicity of RES not only against a panel of drug-resistant cancer cells overexpressing P-glycoprotein/ABCB1, BCRP/ABCG2, ABCB5 (ATP-binding cassette transporters), but also mutation-activated EGFR. The assessment of proteins expression was done by Western blot analysis. COMPARE and hierarchical…
Human ABCB1 confers cells resistance to cytotoxic guanidine alkaloids from Pterogyne nitens.
2015
Multidrug resistance (MDR) caused by human ABCB1 (P-glycoprotein/MDR1) is one of the major obstacles in chemotherapy. To understand the mechanism of MDR by ABCB1 and circumvent the MDR, in the present study, we established human ABCB1-expressing cells (Flp-In-293/ABCB1 cells) and examined the cytotoxic effects of four guanidine alkaloids from Pterogyne nitens (galegine, nitensidine A, pterogynidine and pterogynine) using Flp-In-293/Mock and Flp-In-293/ABCB1 cells. The activity of ABCB1 in Flp-In-293/ABCB1 cells were confirmed by typical substrates for ABCB1 (taxol and vinblastine) in MTT assay. Flp-In-293/ABCB1 cells were also resistant to the four guanidine alkaloids as well as taxol and v…
Cytotoxicity of 35 medicinal plants from Sudan towards sensitive and multidrug-resistant cancer cells
2015
Abstract Background Cancer is a complex disease with multiple genetic and epigenetic alterations. Since decades, the hallmark of cancer therapy is chemotherapy. Cytotoxic drugs erase rapidly dividing cells without sufficient differentiation between normal and cancerous cells resulting in severe side effects in normal tissues. Recently, strategies for cancer treatment focused on targeting specific proteins involved in tumor growth and progression. The present study was designed to investigate the cytotoxicity of 65 crude extracts from 35 Sudanese medicinal plants towards various cancer cell lines expressing molecular mechanisms of resistance towards classical chemotherapeutics (two ATP-bindi…
Nitensidine A, a guanidine alkaloid from Pterogyne nitens, is a novel substrate for human ABC transporter ABCB1.
2014
The Pterogyne nitens (Fabaceae) tree, native to South America, has been found to produce guanidine alkaloids as well as bioactive flavonols such as kaempferol, quercetin, and rutin. In the present study, we examined the possibility of interaction between human ATP-binding cassette (ABC) transporter ABCB1 and four guanidine alkaloids isolated from P. nitens (i.e., galegine, nitensidine A, pterogynidine, and pterogynine) using human T cell lymphoblast-like leukemia cell line CCRF-CEM and its multi-drug resistant (MDR) counterpart CEM/ADR5000. In XTT assays, CEM/ADR5000 cells were resistant to the four guanidine alkaloids compared to CCRF-CEM cells, although the four guanidine alkaloids exhibi…
The lignan, (-)-sesamin reveals cytotoxicity toward cancer cells: pharmacogenomic determination of genes associated with sensitivity or resistance.
2013
(-)-Sesamin is a lignan present in sesam oil and a number of medicinal plants. It exerts various pharmacological effects, such as prevention of hyperlipidemia, hypertension, and carcinogenesis. Moreover, (-)-sesamin has chemopreventive and anticancer activity in vitro and in vivo. Multidrug resistance (MDR) of tumors leads to fatal treatment outcome in many patients and novel drugs able to kill multidrug-resistant cells are urgently needed. P-glycoprotein (MDR1/ABCB1) is the best known ATP-binding cassette (ABC) drug transporter mediating MDR. ABCB5 is a close relative to ABCB1, which also mediates MDR. We found that the mRNA expressions of ABCB1 and ABCB5 were not related to the 50% inhibi…
Interactions between artemisinin derivatives and P-glycoprotein
2019
Abstract Background Artemisinin was isolated and identified in 1972, which was the starting point for a new era in antimalarial drug therapy. Furthermore, numerous studies have demonstrated that artemisinin and its derivatives exhibit considerable anticancer activity both in vitro, in vivo, and even in clinical Phase I/II trials. P-glycoprotein (P-gp) mediated multi-drug resistance (MDR) is one of the most serious causes of chemotherapy failure in cancer treatment. Interestingly, many artemisinin derivatives exhibit excellent ability to overcome P-gp mediated MDR and even show collateral sensitivity against MDR cancer cells. Furthermore, some artemisinin derivatives show P-gp-mediated MDR r…