Search results for " Positive"
showing 10 items of 397 documents
Tyrosine Kinase Inhibitors for the Treatment of Chronic Myeloid Leukemia
2009
Imatinib mesylate (Gleevec) is a drug unique for the treatment of certain forms of cancer. It works by targeting, and turning off, specific tyrosine kinase proteins that cause the uncontrolled cell growth and the inhibition of apoptosis in cancer cells. Imatinib was designed on the basis of the structure of the ATP binding site of the Abl protein kinase with the aim to stabilizes the inactive form of Bcr-Abl, an oncoprotein involved in malignant transformation in chronic myelogenous leukemia (CML). However, imatinib can also target other tyrosine kinase proteins different from Bcr-Abl such as Kit, that is the suspected cause of gastrointestinal stromal tumor (GIST). Despite successful clini…
The new iodoacetamidobenzofuran derivative TR120 decreases STAT5 expression and induces antitumor effects in imatinib-sensitive and imatinib-resistan…
2013
The identification of novel compounds modulating the expression/activity of molecular targets downstream to BCR-ABL could be a new approach in the treatment of chronic myeloid leukemias (CMLs) resistant to imatinib or other BCR-ABL-targeted molecules. Recently, we synthesized a new class of substituted 2-(3,4,5-trimethoxybenzoyl)-2-N,N-dimethylamino-benzo[b]furans, and among these 3-iodoacetylamino-6-methoxybenzofuran-2-yl(3,5-trimethoxyphenyl)methanone (TR120) showed marked cytotoxic activity in BCR-ABL-expressing cells. Interestingly, TR120 was more potent than imatinib in cell growth inhibition and apoptosis induction in both BCR-ABL-expressing K562 and KCL22 cells. Moreover, it showed a…
In BCR-ABL-positive cells, STAT-5 tyrosine-phosphorylation integrates signals induced by imatinib mesylate and Ara-C.
2003
In BCR-ABL-positive cells, the transcription factor STAT-5 is constitutively activated by tyrosine phosphorylation. STAT-5 activation results in upregulation of bcl-X(L) and increased resistance to induction of apoptosis. Here, we investigated the effects of imatinib mesylate and cytosine arabinoside (Ara-C) on STAT-5 tyrosine-phosphorylation, cellular proliferation and induction of apoptosis in cell lines and primary hematopoietic cells. Imatinib mesylate treatment strongly suppressed STAT-5 tyrosine-phosphorylation in K562 and primary CML blasts. In contrast to JAK-2 and PI-3-kinase inhibition, exposure of K562 cells to imatinib mesylate resulted in obvious suppression of proliferation. R…
Galangin increases the cytotoxic activity of imatinib mesylate in imatinib-sensitive and imatinib-resistant Bcr-Abl expressing leukemia cells
2008
Resistance to imatinib mesylate is an emergent problem in the treatment of Bcr-Abl expressing myelogenous leukemias and additional therapeutic strategies are required. We observed that galangin, a non-toxic, naturally occurring flavonoid was effective as anti-proliferative, and apoptotic agent in Bcr-Abl expressing K562 and KCL22 cells and in imatinib mesylate resistant K562-R and KCL22-R cells. Galangin induced an arrest of cells in G0–G1phase of cell cycle and a decrease in pRb, cdk4, cdk1, cycline B levels; moreover, it was able to induce a monocytic differentiation of leukemic Bcr-Abl+ cells. Of note, galangin caused a decrease in Bcl-2 levels and markedly increased the apoptotic activi…
Carboxyamidotriazole inhibits cell growth of imatinib-resistant chronic myeloid leukaemia cells including T315I Bcr-Abl mutant by a redox-mediated me…
2010
Mutation of the Bcr–Abl oncoprotein is one of most frequent mechanisms by which chronic myelogenous leukemia (CML) cells become resistant to imatinib. Here, we show that treat- ment of cell lines harbouring wild type or mutant BCR–ABL with carboxyamidotriazole (CAI), a calcium influx and signal transduction inhibitor, inhibits cell growth, the expres- sion of Bcr–Abl and its downstream signalling, and induces apoptosis. Moreover, we show that CAI acts by increasing intracellular ROS. Clinically significant, CAI has also inhibitory effects on T315I Bcr–Abl mutant, a mutation that causes CML cells to become insensitive to imatinib and second generation abl kinase inhibitors.
Efficacy and safety of bosutinib (BOS) for Philadelphia chromosome–positive (Ph+) leukemia in older versus younger patients (pts).
2012
6511 Background: BOS is an oral dual Src/Abl kinase inhibitor with potent activity in Ph+ leukemia. Methods: Efficacy and safety of BOS 500 mg/d was evaluated in older (≥65 y; n = 119) and younger (<65 y; n = 451) pts in 3 cohorts: chronic phase chronic myeloid leukemia (CP CML) after imatinib (IM; CP2L cohort; n = 287); CP CML after IM + dasatinib (DAS) and/or nilotinib (NIL; CP3L cohort; n = 119); and accelerated/blast phase (AP/BP) CML or acute lymphoblastic leukemia after IM ± DAS and/or NIL (ADV cohort; n = 164). Results: Baseline events (≥65 y vs <65 y) included respiratory disorders (35% vs 13%), cardiac disorders (29% vs 9%), and diabetes (4% vs 4%). Median baseline medicatio…
Assessment for the mean value total dressing method: Comparison with coupled cluster including triples methods for BF, NO+, CN+, C2, BeO, NH3, CH2, H…
1997
Limited previous experience with the mean value total dressing (MVTD) method had shown that MVTD energies for closed shell systems are generally better than CCSD(T) ones compared to FCI. The method, previously published as total dressing 2′(td-2′), is based on the single reference intermediate Hamiltonian theory. It is not a CC method but deals in a great part with the same physical effects that CC methods that incorporate amplitudes of triples such as CCSDT or its CCSDT-1n approaches. A number of test calculations comparing to diverse CC methods, as well as FCI and experiment when available, have been performed. The tests concern equilibrium energies in NH3 and CH2, equilibrium energies an…
Kinetic modeling of ion conduction in KcsA potassium channel.
2005
KcsA constitutes a potassium channel of known structure that shows both high conduction rates and selectivity among monovalent cations. A kinetic model for ion conduction through this channel that assumes rapid ion transport within the filter has recently been presented by Nelson. In a recent, brief communication, we used the model to provide preliminary explanations to the experimental current-voltage J-V and conductance-concentration g-S curves obtained for a series of monovalent ions (K(+),Tl(+), and Rb(+)). We did not assume rapid ion transport in the calculations, since ion transport within the selectivity filter could be rate limiting for ions other than native K(+). This previous wor…
Accuracy, Reliability, and Safety of Luminol in Bloodstain Investigation
2002
ABSTRACTThe reliability of luminol as a presumptive test reagent was studied in this work. The possibility of obtaining a false negative subsequent to contamination of the test specimen was determined. The behavior of luminol with respect to a contaminant was compared to other reagents used in similar tests. Following an analysis of the test results, other test sensitivity, and safety data, it was concluded that luminol is a more reliable reagent than others due to a higher improbability of producing false positives and false negatives, apart from being safer than other substances. It should, therefore, be considered as a “preferable” or “first choice” reagent for use in presumptive tests.
Cartes et élections : la construction des circonscriptions électorales aux Etats-Unis, entre égalité et équité
2003
Maps and Elections : The Construction of Electoral Districts in the USA. Decennal census-led redistricting in the United States is the occasion for court actions focused nowadays on the political representation of ethnic minorities. Computer tools make possible the building of districts specifically tailored for Blacks or Hispanics, but blatant racial gerrymandering is now rejected by the US Supreme Court. This paper examines the most relevant judicial decisions and describes several local cases.