Multicenter performance evaluation of the MultiDrugQuant assay kit.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e21140-e21140
Author(s):  
Peter Krajcsi ◽  
Katalin Tauber Jakab ◽  
Sandor Barath ◽  
Edit Gyimesi ◽  
Zsuzsanna Hevessy ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Mononuclear Cells ◽  
Fluorescent Dyes ◽  
Clinical Laboratory ◽  
Diagnostic Methods ◽  
Cytotoxic Agents ◽  
Efflux Transporters ◽  
Target Cells ◽  
Functional Assay ◽  
Fluorescent Intensity

e21140 Background: Multidrug resistance is the most frequent type of resistance to anticancer chemotherapy, which usually results from the overexpression of efflux transporters, such as the MDR1, MRP1 and BCRP. Unfortunatelly, neither the genetic polymorphisms nor the mRNA/protein expression levels correlate closely with the functional activity. On the other hand, although the functional methods separately gave promising results, standardization and reproducibility of these tests failed to conform with values required from routine diagnostic methods. MultiDrugQuant (MDQ) kit was developed as an improved functional assay system, which can measure the multidrug resistance activity of the three, clinically most relevant efflux transporters using flow cytometry in living tumor cells. The present study aimed to carry out the laboratory validation and to evaluate the performance of the MDQ-kit. Methods: Validation of the kit was carried out according to the standards of the Clinical Laboratory Standards Institute in three university centres. Mononuclear cells were separated using Ficoll gradient and tested at 2-5×106/ml within 6 hours after specimen collection. Activities of the multidrug transporters were calculated from the difference between the mean fluorescent intensity of cells w/o the specific inhibitors, respectively. Inaccuracy and comparative measurements were carried out using cell lines with low and high activity of the transporters. Results on different flow cytometers were compared using CD45 CD19 or CD3 monoclonal antibodies for gating the population of interest. Results: The assay proved to be specific and robust at various concentrations of the fluorescent dyes (10-100 % of the original) or inhibitors (50-150 % of the original). Both intraassay and interassay reproducibilities were <5 %. Multidrug resistance activity values determined on different flow cytometers were comparable and eligible. Conclusions: The MDQ assay provides quantitative results on the activity of the MDR1, MRP1 and BCRP in the target cells, which might be used to predict the resistance of these cells to particular cytotoxic agents. Recently, the MDQ-kit has been registered for in vitro diagnostic use in the EU.

scholarly journals Fructose Induces Fluconazole Resistance in Candida albicans through Activation of Mdr1 and Cdr1 Transporters

2021 ◽  
Vol 22 (4) ◽  
pp. 2127
Author(s):  
Jakub Suchodolski ◽  
Anna Krasowska
Keyword(s):  
Candida Albicans ◽  
Multidrug Resistance ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
De Novo ◽  
Pathogenic Fungus ◽  
Serum Levels ◽  
Efflux Transporters ◽  
Fluconazole Resistance ◽  
Green Fluorescent

Candida albicans is a pathogenic fungus that is increasingly developing multidrug resistance (MDR), including resistance to azole drugs such as fluconazole (FLC). This is partially a result of the increased synthesis of membrane efflux transporters Cdr1p, Cdr2p, and Mdr1p. Although all these proteins can export FLC, only Cdr1p is expressed constitutively. In this study, the effect of elevated fructose, as a carbon source, on the MDR was evaluated. It was shown that fructose, elevated in the serum of diabetics, promotes FLC resistance. Using C. albicans strains with green fluorescent protein (GFP) tagged MDR transporters, it was determined that the FLC-resistance phenotype occurs as a result of Mdr1p activation and via the increased induction of higher Cdr1p levels. It was observed that fructose-grown C. albicans cells displayed a high efflux activity of both transporters as opposed to glucose-grown cells, which synthesize Cdr1p but not Mdr1p. Additionally, it was concluded that elevated fructose serum levels induce the de novo production of Mdr1p after 60 min. In combination with glucose, however, fructose induces Mdr1p production as soon as after 30 min. It is proposed that fructose may be one of the biochemical factors responsible for Mdr1p production in C. albicans cells.

scholarly journals Blood functional assay for rapid clinical interpretation of germline TP53 variants

2020 ◽  
pp. jmedgenet-2020-107059 ◽  
Author(s):  
Sabine Raad ◽  
Marion Rolain ◽  
Sophie Coutant ◽  
Céline Derambure ◽  
Raphael Lanos ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Transcriptional Response ◽  
Functional Assay ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Patients With Cancer ◽  
Pathogenic Variants ◽  
Functional Variants ◽  
Multiplex Ligation Probe Amplification ◽  
P53 Mrna

BackgroundThe interpretation of germline TP53 variants is critical to ensure appropriate medical management of patients with cancer and follow-up of variant carriers. This interpretation remains complex and is becoming a growing challenge considering the exponential increase in TP53 tests. We developed a functional assay directly performed on patients’ blood.MethodsPeripheral blood mononuclear cells were cultured, activated, exposed to doxorubicin and the p53-mediated transcriptional response was quantified using reverse transcription–multiplex ligation probe amplification and RT-QMPSF assays, including 10 p53 targets selected from transcriptome analysis, and two amplicons to measure p53 mRNA levels. We applied this blood functional assay to 77 patients addressed for TP53 analysis.ResultsIn 51 wild-type TP53 individuals, the mean p53 functionality score was 12.7 (range 7.5–22.8). Among eight individuals harbouring likely pathogenic or pathogenic variants, the scores were reduced (mean 4.8, range 3.1–7.1), and p53 mRNA levels were reduced in patients harbouring truncating variants. We tested 14 rare unclassified variants (p.(Pro72His), p.(Gly105Asp), p.(Arg110His), p.(Phe134Leu), p.(Arg158Cys), p.(Pro191Arg), p.(Pro278Arg), p.(Arg283Cys), p.(Leu348Ser), p.(Asp352Tyr), p.(Gly108_Phe109delinsVal), p.(Asn131del), p.(Leu265del), c.-117G>T) and 12 yielded functionally abnormal scores. Remarkably, the assay revealed that the c.*1175A>C polymorphic variant within TP53 poly-adenylation site can impact p53 function with the same magnitude as a null variant, when present on both alleles, and may act as a modifying factor in pathogenic variant carriers.ConclusionThis blood p53 assay should therefore be a useful tool for the rapid clinical classification of germline TP53 variants and detection of non-coding functional variants.

scholarly journals A non-human primate in vitro functional assay for the early evaluation of TB vaccine candidates

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Rachel Tanner ◽  
Andrew D. White ◽  
Charelle Boot ◽  
Claudia C. Sombroek ◽  
Matthew K. O’Shea ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Mononuclear Cells ◽  
Functional Assay ◽  
Intermediate Precision ◽  
Peripheral Blood Mononuclear ◽  
Growth Inhibition Assay ◽  
Early Evaluation ◽  
Human Primate

AbstractWe present a non-human primate mycobacterial growth inhibition assay (MGIA) using in vitro blood or cell co-culture with the aim of refining and expediting early tuberculosis vaccine testing. We have taken steps to optimise the assay using cryopreserved peripheral blood mononuclear cells, transfer it to end-user institutes, and assess technical and biological validity. Increasing cell concentration or mycobacterial input and co-culturing in static 48-well plates compared with rotating tubes improved intra-assay repeatability and sensitivity. Standardisation and harmonisation efforts resulted in high consistency agreements, with repeatability and intermediate precision <10% coefficient of variation (CV) and inter-site reproducibility <20% CV; although some systematic differences were observed. As proof-of-concept, we demonstrated ability to detect a BCG vaccine-induced improvement in growth inhibition in macaque samples, and a correlation between MGIA outcome and measures of protection from in vivo disease development following challenge with either intradermal BCG or aerosol/endobronchial Mycobacterium tuberculosis (M.tb) at a group and individual animal level.

scholarly journals Phosphorylation of MgrA and Its Effect on Expression of the NorA and NorB Efflux Pumps of Staphylococcus aureus

2010 ◽  
Vol 192 (10) ◽  
pp. 2525-2534 ◽  
Author(s):  
Que Chi Truong-Bolduc ◽  
David C. Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistance ◽  
Virulence Factors ◽  
Double Mutant ◽  
Efflux Pumps ◽  
Efflux Transporters ◽  
Global Regulator ◽  
Binding Assays ◽  
Genes Encoding ◽  
Gel Shift

ABSTRACT MgrA is a global regulator in Staphylococcus aureus that controls the expression of diverse genes encoding virulence factors and multidrug resistance (MDR) efflux transporters. We identified pknB, which encodes the (Ser/Thr) kinase PknB, in the S. aureus genome. PknB was able to autophosphorylate as well as phosphorylate purified MgrA. We demonstrated that rsbU, which encodes a Ser/Thr phosphatase and is involved in the activation of the SigB regulon, was able to dephosphorylate MgrA-P but not PknB-P. Serines 110 and 113 of MgrA were found to be phosphorylated, and Ala substitutions at these positions resulted in reductions in the level of phosphorylation of MgrA. DNA gel shift binding assays using norA and norB promoters showed that MgrA-P was able to bind the norB promoter but not the norA promoter, a pattern which was the reverse of that for unphosphorylated MgrA. The double mutant MgrAS110A-S113A bound to the norA promoter but not the norB promoter. The double mutant led to a 2-fold decrease in norA transcripts and a 2-fold decrease in the MICs of norfloxacin and ciprofloxacin in strain RN6390. Thus, phosphorylation of MgrA results in loss of binding to the norA promoter, but with a gain of the ability to bind the norB promoter. Loss of the ability to phosphorylate MgrA by Ala substitution resulted in increased repression of norA expression and in reductions in susceptibilities to NorA substrates.

Functional study of multidrug resistance with fluorescent dyes. Limits of the assay for low levels of resistance and application in clinical samples

1996 ◽  
Vol 106 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Yvan Canitrot ◽  
Sylvie Lahmy ◽  
Jean-Jacques Buquen ◽  
Damien Canitrot ◽  
Dominique Lautier
Keyword(s):  
Multidrug Resistance ◽  
Fluorescent Dyes ◽  
Functional Study ◽  
Clinical Samples ◽  
Low Levels

New Strategies for the Treatment of Acute Myeloid Leukemia Including Antibodies and Other Novel Agents

Hematology ◽  
2005 ◽  
Vol 2005 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Martin S. Tallman
Keyword(s):  
Older Adults ◽  
Acute Myeloid Leukemia ◽  
Multidrug Resistance ◽  
Myeloid Leukemia ◽  
Cytotoxic Agents ◽  
High Dose ◽  
Farnesyltransferase Inhibitors ◽  
Younger Adults ◽  
The Impact ◽  
Acute Myeloid

Abstract The prognosis for younger adults (≤ 55–60 years) with acute myeloid leukemia (AML) has improved during the last four decades. However, there has been little progress in the treatment of older adults. This disappointing observation is important because the median age of patients with AML is about 70 years. Approximately 60%–80% of younger adults with AML achieve complete remission (CR) with the cytotoxic agents cytarabine and an anthracycline such as daunorubicin or idarubicin or the anthracenedione mitoxantrone. However, only 30%–40% of such patients are alive and disease-free at 5 years. Among older adults, CR is achieved in 40%–55%, but there are very few long-term survivors. Many studies have evaluated the impact of alternative doses and schedules, as well as additional cytotoxic drugs, on the prognosis for this group of patients. The outcome has not improved substantially beyond that achieved with conventional doses of an anthracycline and cytarabine followed by high-dose cytarabine consolidation. Several factors identified at diagnosis can predict outcome. The most important of these is the karyotype of the leukemic cells. Another critical factor is the presence of transmembrane transporter proteins, which confer multidrug resistance and mutations in or overexpression of specific genes such as WT1, C/EBPα, BAX, and BCL-2/BAX ratio, BAALC, EVI1, KIT and FLT3. The development of specific agents directed at gene mutations, signal transduction pathways and unique cell surface antigens provide the foundation for new therapeutic strategies. Such agents include the immunoconjugate gemtuzumab ozogamicin, multidrug resistance inhibitors, farnesyltransferase inhibitors, histone deacetylase and proteosome inhibitors, antiangiogenesis agents, FLT3 inhibitors, apoptosis inhibitors, and nucleoside analogs. All of these agents can potentially address the heterogeneous abnormalities in AML and significantly improve the outcome for patients.

Pathogenetic molecular mechanisms of chronic rhinosinusitis with nasal polyps associated with asthma

2021 ◽  
Vol 31 (1) ◽  
pp. 7-19
Author(s):  
O. M. Kurbacheva ◽  
M. E. Dyneva ◽  
I. P. Shilovskiy ◽  
E. L. Savlevich ◽  
V. I. Kovchina ◽  
...  
Keyword(s):  
Chronic Rhinosinusitis ◽  
Inflammatory Cytokines ◽  
Nasal Polyps ◽  
Molecular Mechanisms ◽  
Mononuclear Cells ◽  
Clinical Laboratory ◽  
Compensatory Mechanism ◽  
Local Immunity ◽  
Polyp Tissue ◽  
Anti Inflammatory

The combination of bronchial asthma (BA) and chronic rhinosinusitis with nasal polyps (CRSwNP) is currently considered a separate phenotype wit1 dysregulation of pro- and anti-inflammatory cytokines as one of t1e leading causes of inflammation. The aim of this study was to investigate the local and systemic inflammatory process in patients with BA associated with CRSwNP. Methods. The study enrolled 96 volunteers divided into 4 groups: the 1st was healthy control (Normal); the 2nd had allergic BA associated with CRSwNP; the 3rd had nonallergic BA associated with CRSwNP; the 4th had CRSwNP without BA. All participants of the study underwent clinical, laboratory, instrumental, and histological examinations. The expression of il-1β, il-4, il-,5 il-6, il-13, il-37, il-17f, ifn-γ, tnf-α and tgf-β genes was assessed in the peripheral blood mononuclear cells - PBMC and in the polyp tissue using RT-PCR. We also estimated the expression of tslp, il-25 and il-33 in the polyp tissue and expression of GATA3 and RORgt transcription factors in PBMC. Results. The pathogenesis of BA associated with CRSwNP is characterized by the dys-regulation of the local pro- and anti-inflammatory cytokines of the Th1-, Th2-, Th17- immune response. Moreover, the high expression of il-37 gene in patients with BA associated with CRSwNP, and especially in patients with not-allergic BA associated with CRSwNP, probably indicates the «inclusion» of the compensatory mechanism. In addition, BA associated with CRSwNP is characterized by severe course of both diseases. A nonallergic BA associated with CRSwNP is characterized by more pronounced eosinophilic inflammation, which is an unfavorable prognostic factor. Conclusion. Thus, a comparison of the levels of local and systemic cytokine expression in patients with BA associated with CRSwNP led to the conclusion that CRSwNP affects the local immunity more than systemic immunity. However, the latter is affected to some extent in the long-term as well.

LUPUS NEPHRITE WITH FAST - PROGRESSING CURRENT: CASE REPORT

Vestnik ◽  
2021 ◽  
pp. 143-146
Author(s):  
Б.Г. Султанова ◽  
С.Б. Бодесова ◽  
А.Т. Ибрашева ◽  
Б.С. Мусабаев ◽  
Д.Ш. Бетирова ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Case Report ◽  
Lupus Erythematosus ◽  
Clinical Laboratory ◽  
Rapidly Progressive Glomerulonephritis ◽  
Diagnostic Methods ◽  
Symptomatic Therapy ◽  
Systemic Lupus ◽  
Current Case ◽  
Complex Therapy

В статье описан «неклассический» случай, редко встречающаяся форма заболевания системной красной волчанкой без типичного поражения кожи с проявлением быстропрогрессирующего гломерулонефрита, с поражением тазобедренного сустава, выраженным болевым синдромом у юноши. С применением новых инновационных методов диагностики (непрямая иммунофлюоресценция на анализаторе AKLIDES), что позволило провести своевременно комплексную терапию включая в себя патогенетическую, эфферентную (гемодиализ, плазмаферез), тем самым получен хороший клинический эффект. This article describes a non- racial case of systemic lupus erythematosus with the manifestation of a rapidly progressive glomerulonephritis, hip joint lesion, a pronounced painful syndrom, without dermal manifestations. By the use of new diagnostic methods (immunofluorescence), timely complex therapy: pathogenetic, efferent therapy, symptomatic therapy, it is possible to obtain a fairly good clinical - laboratory- instrumental result.

scholarly journals Compensatory Link between Fusion and Endocytosis of Human Immunodeficiency Virus Type 1 in Human CD4 T Lymphocytes

2004 ◽  
Vol 78 (3) ◽  
pp. 1375-1383 ◽  
Author(s):  
Evelyne Schaeffer ◽  
Vanessa B. Soros ◽  
Warner C. Greene
Keyword(s):  
Human Immunodeficiency Virus ◽  
Mononuclear Cells ◽  
Fluorescent Protein ◽  
Reciprocal Relationship ◽  
Endocytic Pathway ◽  
Productive Infection ◽  
Target Cells ◽  
Concanamycin A ◽  
Immunodeficiency Virus

ABSTRACT Virions of the type 1 human immunodeficiency virus (HIV-1) can enter target cells by fusion or endocytosis, with sharply different functional consequences. Fusion promotes productive infection of the target cell, while endocytosis generally leads to virion inactivation in acidified endosomes or degradation in lysosomes. Virion fusion and endocytosis occur equally in T cells, but these pathways have been regarded as independent because endocytosis of HIV virions requires neither CD4 nor CCR5/CXCR4 engagement in HeLa-CD4 cells. Using flow cytometric techniques to assess the binding and entry of green fluorescent protein (GFP)-Vpr-labeled HIV virions into primary peripheral blood mononuclear cells, we have found that HIV fusion and endocytosis are restricted to the CD4-expressing subset of cells and that both pathways commonly require the initial binding of HIV virions to surface CD4 receptors. Blockade of CXCR4-tropic HIV virion fusion with AMD3100, a CXCR4-specific entry inhibitor, increased virion entry via the endocytic pathway. Similarly, inhibition of endosome acidification with bafilomycin A1, concanamycin A, or NH4Cl enhanced entry via the fusion pathway. Although fusion remained dependent on CD4 and chemokine receptor binding, the endosome inhibitors did not alter surface expression of CD4 and CXCR4. These results suggest that fusion in the presence of the endosome inhibitors likely occurs within nonacidified endosomes. However, the ability of these inhibitors to impair vesicle trafficking from early to late endosomes in some cells could also increase the recycling of these virion-containing endosomes to the cell surface, where fusion occurs. In summary, our results reveal an unexpected, CD4-mediated reciprocal relationship between the pathways governing HIV virion fusion and endocytosis.

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