Search results for "multidrug resistance"
showing 10 items of 84 documents
Self-reported antibiotic stewardship and infection control measures from 57 intensive care units: An international ID-IRI survey
2022
Infection control; Multidrug resistance; Stewardship Control de infección; Resistencia a múltiples fármacos; Administración Control d'infecció; Resistència a múltiples fàrmacs; Administració We explored the self-reported antibiotic stewardship (AS), and infection prevention and control (IPC) activities in intensive care units (ICUs) of different income settings. A cross-sectional study was conducted using an online questionnaire to collect data about IPC and AS measures in participating ICUs. The study participants were Infectious Diseases–International Research Initiative (IDI-IR) members, committed as per their institutional agreement form. We analyzed responses from 57 ICUs in 24 countri…
Antitumor Mechanism of the Essential Oils from Two Succulent Plants in Multidrug Resistance Leukemia Cell
2019
Drug resistance remains a major challenge in the treatment of cancer. The multiplicity of the drug resistance determinants raises the question about the optimal strategies to deal with them. Essential oils showed to inhibit the growth of different tumor cell types. Essential oils contain several chemical classes of compounds whose heterogeneity of active moieties can help prevent the development of drug resistance. In the present paper, we analyzed, by gas chromatography-mass spectrometry the chemical composition of the essential oil of the leaves of Kalanchoe beharensis obtained by hydrodistillation and compared the chemical composition of its essential oil with that of Cyphostemma juttae.…
Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo
2021
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells v…
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…
Liver and gastrointestinal cancers
2020
Abstract One important limitation in the treatment of liver and gastrointestinal cancers is their poor response to available chemotherapy, which is due in part to efficient mechanisms of defense against antitumor drugs. An important role in chemoresistance is played by ATP-binding cassette (ABC) proteins, normally involved in barrier/secretory functions of the digestive apparatus. ABC pumps, often up-regulated in cancers derived from these organs, actively export antitumor agents from cancer cells, thereby reducing the pharmacological effect of these drugs. Among the ABC proteins with the highest impact on the multidrug resistance (MDR) phenotype of many cancer types is MDR1 or P-glycoprote…
Genetic variation and urine cadmium levels: ABCC1 effects in the Strong Heart Family Study
2021
Abstract Genetic effects are suspected to influence cadmium internal dose. Our objective was to assess genetic determinants of urine cadmium in American Indian adults participating in the Strong Heart Family Study (SHFS). Urine cadmium levels and genotyped short tandem repeat (STR) markers were available on 1936 SHFS participants. We investigated heritability, including gene-by-sex and smoking interactions, and STR-based quantitative trait locus (QTL) linkage, using a variance-component decomposition approach, which incorporates the genetic information contained in the pedigrees. We also used available single nucleotide polymorphisms (SNPs) from Illumina’s Metabochip and custom panel to ass…
Impact of combinations of single-nucleotide polymorphisms of anthracycline transporter genes upon the efficacy and toxicity of induction chemotherapy…
2020
Anthracycline uptake could be affected by influx and efflux transporters in acute myeloid leukemia (AML). Combinations of single-nucleotide polymorphisms (SNPs) of wild-type genotype of influx transporters (SLC22A16, SLCO1B1) and homozygous variant genotypes of ABC polymorphisms (ABCB1, ABCC1, ABCC2, ABCG2) were evaluated in 225 adult de novo AML patients. No differences in complete remission were reported, but higher induction death was observed with combinations of SLCO1B1 rs4149056 and ABCB1 (triple variant haplotype, rs1128503), previously associated with ABCB1 and SLCO1B1 SNPs. Several combinations of SLCO1B1 and SLC22A16 with ABCB1 SNPs were associated with higher toxicities, includin…
Variability in human hepatic MRP4 expression: influence of cholestasis and genotype
2007
The multidrug resistance protein 4 (MRP4) is an efflux transporter involved in the transport of endogenous substrates and xenobiotics. We measured MRP4 mRNA and protein expression in human livers and found a 38- and 45-fold variability, respectively. We sequenced 2 kb of the 5'-flanking region, all exons and intron/exon boundaries of the MRP4 gene in 95 patients and identified 74 genetic variants including 10 non-synonymous variations, seven of them being located in highly conserved regions. None of the detected polymorphisms was significantly associated with changes in the MRP4 mRNA or protein expression. Immunofluorescence microscopy indicated that none of the non-synonymous variations af…
Impact of Single Nucleotide Polymorphisms (SNPs) on Immunosuppressive Therapy in Lung Transplantation.
2015
Lung transplant patients present important variability in immunosuppressant blood concentrations during the first months after transplantation. Pharmacogenetics could explain part of this interindividual variability. We evaluated SNPs in genes that have previously shown correlations in other kinds of solid organ transplantation, namely ABCB1 and CYP3A5 genes with tacrolimus (Tac) and ABCC2, UGT1A9 and SLCO1B1 genes with mycophenolic acid (MPA), during the first six months after lung transplantation (51 patients). The genotype was correlated to the trough blood drug concentrations corrected for dose and body weight (C0/Dc). The ABCB1 variant in rs1045642 was associated with significantly hig…
Induction of apoptosis by the adenosine derivative IB-MECA in parental or multidrug-resistant HL-60 leukemia cells: possible relationship to the effe…
2004
<i>Background:</i> The effects of the A<sub>3</sub> adenosine receptor (A<sub>3</sub>AR) agonist IB-MECA were examined in HL-60 leukemia and in its multidrug-resistant variant HL-60R cells. <i>Methods:</i> Cytotoxicity was evaluated by MTS assays and apoptosis by flow cytometry analyses of DNA fragmentation and phosphatidylserine exposure. The mRNAs of A<sub>3</sub>AR and inhibitor of apoptosis proteins (IAPs) were determined by RT-PCR. <i>Results:</i> A<sub>3</sub>AR expression was similar in HL-60 and HL-60R cells. At ≧100 µ<i>M</i>, IB-MECA exhibited strong cytotoxic and apoptotic effects in H…