Search results for "drug resistance"
showing 10 items of 953 documents
Sponge Bcl-2 homologous protein (BHP2-GC) confers distinct stress resistance to human HEK-293 cells
2001
It is established that sponges, the phylogenetically oldest still extant phylum of Metazoa, possess key molecules of the apoptotic pathways, that is members from the Bcl-2 family and a pro-apoptotic molecule with death domains. Here we report on transfection studies of human cells with a sponge gene, GCBHP2. Sponge tissue was exposed to heat shock and tributyltin, which caused an upregulation of gene expression of GCBHP2. The cDNA GCBHP2 was introduced into human HEK-293 cells and mouse NIH-3T3 cells; the stable transfection was confirmed by the identification of the transcripts, by Western blotting as well as by immunofluorescence using antibodies raised against the recombinant polypeptide…
New efficient artemisinin derived agents against human leukemia cells, human cytomegalovirus and Plasmodium falciparum: 2nd generation 1,2,4-trioxane…
2015
Abstract In our ongoing search for highly active hybrid molecules exceeding their parent compounds in anticancer, antimalaria as well as antiviral activity and being an alternative to the standard drugs, we present the synthesis and biological investigations of 2nd generation 1,2,4-trioxane-ferrocene hybrids. In vitro tests against the CCRF-CEM leukemia cell line revealed di-1,2,4-trioxane-ferrocene hybrid 7 as the most active compound (IC50 of 0.01 μM). Regarding the activity against the multidrug resistant subline CEM/ADR5000, 1,2,4-trioxane-ferrocene hybrid 5 showed a remarkable activity (IC50 of 0.53 μM). Contrary to the antimalaria activity of hybrids 4–8 against Plasmodium falciparum …
Ancistrocyclinones A and B, unprecedented pentacyclic N,C-coupled naphthylisoquinoline alkaloids, from the Chinese liana Ancistrocladus tectorius
2018
Two unique pentacyclic N,C-coupled naphthylisoquinolines, the ancistrocyclinones A (5) and B (6), were discovered in the Chinese liana Ancistrocladus tectorius. Furthermore, six known, likewise N,C-coupled alkaloids, viz., ancistrocladinium A (7a) and its mono- and bisphenolic analogs 8a and 9a were isolated, along with their atropo-diastereomers 7b, 8b, and 9b. The stereostructures of 5 and 6 were determined by HRESIMS, 1D and 2D NMR, oxidative degradation, and ECD calculations. The pentacyclic ancistrocyclinones A (5) and B (6) are structurally similar to berberine alkaloids - yet arising from a most different biosynthetic pathway: they are apparently formed by N,C-coupling of their polyk…
ESBL-producing Klebsiella pneumoniae in a University hospital: Molecular features, diffusion of epidemic clones and evaluation of cross-transmission.
2021
The worldwide spread of Klebsiella pneumoniae producing extended-spectrum β-lactamase (ESBL-Kp) is a significant threat. Specifically, various pandemic clones of ESBL-Kp are involved in hospital outbreaks and caused serious infections. In that context, we assessed the phenotypic and molecular features of a collection of ESBL-Kp isolates in a French university hospital and evaluated the occurrence of potential cross-transmissions. Over a 2-year period (2017–2018), 204 non-duplicate isolates of ESBL-Kp were isolated from clinical (n = 118, 57.8%) or screening (n = 86, 42.2%) sample cultures. These isolates were predominantly resistant to cotrimoxazole (88.8%) and ofloxacin (82.8%) but remaine…
Transformation of the dermatophyte Trichophyton mentagrophytes to hygromycin B resistance.
1989
A transformation system for the ringworm-producing dermatophyte Trichophyton mentagrophytes has been developed. The system employs the plasmid pHIS, which contains a bacterial hygromycin B phosphotransferase gene linked to Cochliobolus heterostrophus regulatory sequences (B. G. Turgeon, R. C. Garber, and O. C. Yoder, Mol. Cell. Biol. 7:3297-3305, 1987). This plasmid confers hygromycin B resistance to T. mentagrophytes. The DNA was stably integrated into the fungal genome, and the number and sites of integrations varied among transformants. Transformant clones were capable of infecting guinea pigs. This system opens the way for the molecular genetic analysis of the interaction of T. mentagro…
Clinical resistance to the kinase inhibitor PKC412 in acute myeloid leukemia by mutation of Asn-676 in the FLT3 tyrosine kinase domain.
2005
Activating mutations in the FLT3 tyrosine kinase (TK) occur in approximately 35% of patients with acute myeloid leukemia (AML). Therefore, targeting mutated FLT3 is an attractive therapeutic strategy, and early clinical trials testing FLT3 TK inhibitors (TKI) showed measurable clinical responses. Most of these responses were transient; however, in a subset of patients blast recurrence was preceded by an interval of prolonged remission. The etiology of clinical resistance to FLT3-TKI in AML is unclear but is of major significance for the development of future therapeutic strategies. We searched for mechanisms of resistance in 6 patients with AML who had relapses upon PKC412 treatment. In an …
Induction of cholesterol biosynthesis by archazolid B in T24 bladder cancer cells.
2014
Abstract Background Resistance of cancer cells towards chemotherapeutics represents a major cause of therapy failure. The objective of our study was to evaluate cellular defense strategies in response to the novel vacuolar H+-ATPase inhibitor, archazolid B. Experimental approach: The effects of archazolid B on T24 bladder carcinoma cells were investigated by combining “omics” technologies (transcriptomics (mRNA and miRNA) and proteomics). Free cholesterol distribution was determined by filipin staining using flow cytometry and fluorescence microscopy. Flow cytometry was performed for LDLR surface expression studies. Uptake of LDL cholesterol was visualized by confocal microscopy. SREBP acti…
IL-4-mediated drug resistance in colon cancer stem cells
2008
Cancer stem cells are defined as cells able to both extensively self-renew and differentiate into progenitors. Cancer stem cells are thus likely to be responsible for maintaining or spreading a cancer, and may be the most relevant targets for cancer therapy. The CD133 glycoprotein was recently described as a reliable cancer stem-like cell marker in colon carcinoma. CD133+ cells are both necessary and sufficient to initiate tumour growth in animal models. The CD133+ cell population and spheroid cultures contain cells expressing the stem cell marker Musashi-1 which is involved in maintenance of stem cell fate in several tissues and importantly, this expression is maintained in stem-like cells…
Bloodstream infections in intensive care unit patients: distribution and antibiotic resistance of bacteria
2015
Vincenzo Russotto,1 Andrea Cortegiani,1 Giorgio Graziano,2 Laura Saporito,2 Santi Maurizio Raineri,1 Caterina Mammina,2 Antonino Giarratano1 1Department of Biopathology and Medical Biotechnologies (DIBIMED), Section of Anaesthesia, Analgesia, Intensive Care and Emergency, Paolo Giaccone University Hospital, University of Palermo, Palermo, Italy; 2Department of Sciences for Health Promotion and Mother-Child Care, University of Palermo, Palermo, Italy Abstract: Bloodstream infections (BSIs) are among the leading infections in critically ill patients. The case-fatality rate associated with BSIs in patients admitted to intensive care units (ICUs) reaches 35%–50%. The emergence and dif…
Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials…
2019
Pardo-Oviedo, Juan Mauricio/0000-0003-0084-3449; Lopez-Delgado, Juan Carlos/0000-0003-3324-1129; Corradi, Francesco/0000-0002-5588-2608; De Backer, Daniel/0000-0001-9841-5762; POTA, VINCENZO/0000-0001-9999-3388; Tomescu, Dana/0000-0001-9673-5754; Sabetian, Golnar/0000-0001-8764-2150; Girardis, Massimo/0000-0002-2453-0829; Brazzi, Luca/0000-0001-7059-0622; Leone, Marc/0000-0002-3097-758X; Zabolotskikh, Igor Borisovich/0000-0002-3623-2546; De Lange, Dylan/0000-0002-0191-7270; ALMEKHLAFI, GHALEB A./0000-0002-0323-7025; Elke, Gunnar/0000-0002-4948-1605; Grigoras, Ioana/0000-0001-9412-9574; Czuczwar, Miroslaw/0000-0002-9025-6717; Nora, David/0000-0002-1133-7368; Masjedi, Mansoor/0000-0001-6175-9…