Search results for " MDR"

Selective downregulation of the MDR1 gene product in Caco-2 cells by stable transfection to prove its relevance in secretory drug transport.

2005

Considerable interest is focused on overcoming multidrug resistance (MDR) in cancer chemotherapy. The in vitro experiments to characterize P-glycoprotein's (P-gp) function and to decrease its effects have led to a variety of strategies such as addition of competitors or supplementation of the medium with oligonucleotides complementary to the 5'-end of the MDR1-mRNA. For the Caco-2 cell line, an in vitro model for absorption screening, expressing multiple transporters including P-gp, which pumps substances back into the apical solution, P-gp activity might mask other relevant transport proteins' activity. The objective of the present study was to construct a Caco-2 subline with reduced P-gp …

Molecular epidemiology of Acinetobacter baumannii in Iran: endemic and epidemic spread of multiresistant isolates

2014

Objectives We examined the molecular epidemiology of Acinetobacter baumannii clinical isolates from two cities (Tehran and Tabriz) of Iran. Methods DiversiLab repetitive extragenic palindromic PCR (rep-PCR), multilocus sequence typing and sequence group multiplex PCR were performed. The presence of resistance mechanisms including metallo-β-lactamases, extended-spectrum β-lactamases, OXA carbapenemases, aminoglycoside-modifying enzymes and RNA methylases was also investigated. Results DiversiLab rep-PCR identified 11 clusters and 11 singleton isolates. Twelve sequence types (STs), including six novel types, were identified. Sequence groups (SGs) 1-3 as well as five additional banding pattern…

Dissemination of a Carbapenem-Resistant Acinetobacter baumannii Strain Belonging to International Clone II/Sequence Type 2 and Harboring a Novel AbaR…

2013

ABSTRACT An outbreak of hospital-acquired Acinetobacter baumannii infections, caused by a bla OXA-23 -positive carbapenem-resistant strain belonging to international clone II/ST2, was detected in Latvia. The strain was partially equipped with the armA gene and the intI1-aacA4-catB8-aadA1-qacE Δ 1 class 1 integron. In addition, the strain carried AbaR25, a novel AbaR4-like resistance island of ∼46,500 bp containing structures similar to the previously described AbaR22 and Tn 6167 islands. AbaR25 was characterized by the occurrence of a second copy of Tn 6022a interrupted by Tn 2006 carrying the bla OXA-23 gene.

Correlation between GP-170 expression, prognosis, and chemoresistance of superficial bladder carcinoma.

2003

To study GP-170 in superficial bladder cancer at initial diagnosis and at recurrence and to evaluate if intravesical chemoprophylaxis modifies the expression of GP-170 in tumor recurrences. GP-170 was retrospectively assessed in 160 patients affected by primary superficial transitional cell carcinoma of the bladder and followed for up to 10 years. Eighty-four patients (52.5%) recurred after transurethral resection (TUR). Adjuvant intravesical chemotherapy after TUR was adopted in 52 patients. The correlations between GP-170 and G-grade, T-category, risk of recurrence and of progression, and adoption of adjuvant intravesical chemotherapy were investigated. The correlations between variations…

Asymmetric synthesis and biological evaluation of 1,2,4-Oxadiazoles analogues of Linezolid

2014

Oxazolidinones are a class of antibacterial agents which displayed activity againist a variety of gram-positive pathogens and are highly potent against multidrug-resistant bacteria. Linezolid is the first oxazolidinone antibiotic approved for clinical use but linezolid resistance began to appear. 1,2,4 – Oxadiazoles are known bioactive heterocycles whose activity has been often associated to their bioisosterism with amide or ester functionalities [1]. As results of a research project on the molecular design of heterocycle – based antibacterials to contrast Multi-Drug Resistance (MDR) [2], we report the synthesis of 1,2,4 - Oxadiazole analogues of Linezolid. The synthesis has been achieved b…

Antitumor effects of curcumin and structurally β-diketone modified analogs on multidrug resistant cancer cells

2007

Abstract Using concepts of bioisostery a series of curcumin analogs were synthesized: the diketonic system of the compound was elaborated into enaminones, oximes, and the isoxazole heterocycle. The cell growth inhibitory and apoptosis inducing effects of the new analogs were evaluated by in vitro assays in the hepatocellular carcinoma HA22T/VGH cells, as well as in the MCF-7 breast cancer cell line and in its multidrug resistant (MDR) variant MCF-7R. Increased antitumor activity on all cell lines was found with the isoxazole analog and especially with the benzyl oxime derivative; in the HA22T/VGH cell model, the latter compound inhibited constitutive NF-κB activation.

Colonizzazione da batteri Gram negativi multi-resistenti in pazienti pediatrici

2017

INTRODUZIONE: La diffusione della resistenza batterica in ospedale e in comunità costituisce un serio motivo di allarme anche nella popolazione pediatrica. Recenti studi hanno dimostrato come le infezioni sostenute da batteri gram-negativi multiresistenti (MDRGN) oggi si presentino sempre più frequentemente anche in comunità, e come più del 15% dei bambini siano colonizzati da MDRGN al momento del ricovero in ospedale. L’introduzione di questi microrganismi in comunità rappresenta un serio fattore di rischio per lo sviluppo di infezioni difficilmente trattabili. Il nostro studio ha indagato la presenza di batteri MDRGN nella popolazione microbica intestinale di bambini ricoverati con sintom…

Comparison of multidrug-resistant extraintestinal pathogenic Escherichia coli from human, foods and animals to investigate the possible chains of tra…

Background Globally, antimicrobial drug resistant Escherichia coli is the most common etiological agent of invasive disease in humans. In Europe, increasing proportions of infections due to third generation cephalosporins (3GCs) and/or fluoroquinolone resistant extraintestinal pathogenic E. coli (ExPEC) strains are reported. It has been shown that multidrug resistant (MDR) E. coli can be transmitted from animals to humans and based on existing evidence, poultry is the food animal source most closely linked to human E. coli. However, lack of reliable data makes it difficult to assess the attributable risk of different food sources and their impact on human health. Objectives In the present s…

MOLECULAR CHARACTERIZATION OF MULTIDRUG-RESISTANT E. COLI ISOLATED FROM BACTEREMIA PATIENTS

2014

Background: Extraintestinal pathogenic Escherichia coli (ExPEC) bacteria have the ability to cause diverse and serious diseases, such as urinary tract infections (UTIs) and bacteremia; incidence of bacteremia is increasing globally. The emergence of multidrug resistance in E. coli is also becoming a global concern, with particular emphasis on E. coli sequence type (ST) 131, which is being increasingly reported in UTIs. Drug resistance is mediated by extended- spectrum β-lactamases (ESBLs), mainly of the CTX-M family, particularly CTX-M-15, and less frequently of the SHV and OXA families. Few studies are available regarding the characterization of E. coli strains causing bacteremia. Methods:…

Epidemiology and Pattern of Resistance of Gram-Negative Bacteria Isolated from Blood Samples in Hospitalized Patients: A Single Center Retrospective …

2021

Background: Blood culturing remains the mainstream tool to inform an appropriate treatment in hospital-acquired bloodstream infections and to diagnose any bacteremia. Methods: A retrospective investigation on the prevalence of Gram-negative bacteria (GNB) and their resistance in hospitalized patients by age, sex, and units from blood cultures (BCs) was conducted from January 2018 to April 2020 at Sant’Elia hospital, Caltanissetta, southern Italy. We divided the patient age range into four equal intervals. Results: Multivariate demographic and microbiological variables did not show an association between bacteria distributions and gender and age. The distribution by units showed a higher pre…