Search results for "URACIL"
showing 10 items of 343 documents
Transplantation of prodrug-converting neural progenitor cells for brain tumor therapy
2003
Since neural progenitor cells can engraft stably into brain tumors and differentiate along the neuronal and glial line, we tested the hypothesis that transplanted cytosine deaminase (CD)-expressing ST14A cells (an immortalized neural progenitor cell line) can convert locally 5-fluorocytosine (5-FC) into 5-fluorouracil (5-FU) and produce a regression of glioma tumors. ST14A, retrovirally transduced with the E. coli CD gene, showed a strong bystander effect on glioma cells as assessed by in vitro assay. Intracerebral injection of C6 glioma cells generated a rapidly growing tumoral mass. DiI prelabeled ST14A, coinjected into the rat brain with C6 glioma cells, survived in the tumoral mass up t…
A French prospective pilot study for identifying dihydropyrimidine dehydrogenase (DPD) deficiency in breast cancer patients (pts) receiving capecitab…
2013
e13519 Background: For fluoropyrimidines, and especially cap, Health Authorities point out that DPD deficiency confers a significant risk of major toxicity (tox). Identification of at-risk pts is thus relevant. This multicentric prospective study of the French GPCO group (Groupe de Pharmacologie Clinique Oncologique, Unicancer) evaluated the sensitivity, specificity and predictive values of DPD phenotyping and genotyping for predicting severe cap-related tox in metastatic breast cancer pts. Methods: 303 pts were included (15 institutions), 88% received cap as monotherapy, 28% were treated as first line (mean dose at 1st cycle 1957 mg/m2/d). Pre-treatment dihydrouracil (UH2) and uracil (U) …
Dificultad en el tratamiento del hipertiroidismo por amiodarona: Presentación de un caso
2007
La amiodarona puede alterar la función tiroidea en un 15-20% de los pacientes que la toman, dando lugar a hipotiroidismo o hipertiroidismo. La sobrecarga de yodo y la toxicidad directa sobre el tiroides inducida por amiodarona pueden provocar hipertiroidismo. Describimos un caso de tirotoxicosis grave por amiodarona que se diagnosticó buscando la causa que descompensó la cardiopatía de base del paciente, condicionando ésta el pronóstico y el manejo terapéutico. El tratamiento precisó un estrecho seguimiento y se basó en dosis elevadas de propiltiouracilo y dexametasona que no controlaron las consecuencias del hipertiroidismo a nivel cardiaco necesitando la tiroidectomia total. Creemos, con …
Binucleate cells in the Ehrlich ascites tumor. Action of 5-fluorouracil.
1987
Time-dependent frequency distribution of binucleate cells (BC) was studied in Ehrlich ascites tumor (EAT) growing in mice. In animals that received no further treatment, the number of BC increased slowly from 2.6% to 16.5% of total cells within 8 days. In animals that were treated with different doses of 5-fluorouracil (FU) we found clearly higher numbers of BC. The number of BC increased with tumor age. The increase observed after treatment was reached more quickly in animals that had received the highest FU dose. The final number of BC was also dependent on the age of the tumor at the time of FU injection.
Binucleate cells in the Ehrlich ascites tumor. Autoradiographic labeling
1989
Abstract An autoradiographic study was performed on binucleate and mitotic cells in the Ehrlich ascites tumor (EAT) untreated and after treatment with 5-fluorouracil (FU). The number of binucleate cells was greater in the treated tumor than in the controls. It was also observed that the number of labeled mitoses was greater in the Fu-treated tumor. Autoradiographic labeling showed that the cells that proved to be binucleate had previously passed through S-phase; thus, these cells belonged to the proliferative compartment.
Antitumoural properties of benzannelated seven-membered 5-fluorouracil derivatives and related open analogues. Molecular markers for apoptosis and ce…
2005
Attention is increasingly being focussed on the cell cycle and apoptosis as potential targets for therapeutic intervention in cancer. We prepared a series of bioisosteric benzannelated seven-membered 5-FU O,N-acetals to test them against the MCF-7 human breast cancer cell line. Benzo-fused seven-membered O,O-acetals or their acyclic analogues led to the expected 5-FU O,N-acetals (or aminals), in addition to six- and 14-membered aminal structures and acyclic compounds. All the cyclic aminals provoked a G0/G1-phase cell cycle arrest, whereas Ftorafur, a known prodrug of 5-FU, and 1-[2-(2-hydroxymethyl-4-nitrophenoxy)-1-methoxyethyl]-5-fluorouracil (11) induced an S-phase cell cycle arrest. Al…
On the relaxation mechanisms of 6-azauracil
2011
The nonadiabatic photochemistry of 6-azauracil has been studied by means of the CASPT2//CASSCF protocol and double-ζ plus polarization ANO basis sets. Minimum energy states, transition states, minimum energy paths, and surface intersections have been computed in order to obtain an accurate description of several potential energy hypersurfaces. It is concluded that, after absorption of ultraviolet radiation (248 nm), two main relaxation mechanisms may occur, via which the lowest (3)(ππ*) state can be populated. The first one takes place via a conical intersection involving the bright (1)(ππ*) and the lowest (1)(nπ*) states, ((1)ππ*/(1)nπ*)(CI), from which a low-energy singlet-triplet crossin…
Performance of Markers and the Homologous Series Method for Dead Time Estimation in Reversed-Phase Liquid Chromatography
2009
Abstract Two methods for dead time estimation (the use of markers and the homologous series mathematical method) are revised. Out of twelve assayed common markers, only KBr, KI, tartrazine, thiourea, uracil, and urea yielded retention times independent of the mobile phase composition in the range 10–90% acetonitrile, using a Zorbax Eclipse XDB−C18 column. On the other hand, the quality of the estimations provided by the homologous series method was limited by the mathematical approach and the data quality. With this method, the estimated dead time is an extrapolated value, which is severely affected by the data of the most retained compounds that act as leverage points, biasing the result. …
Cetuximab, fluorouracil (5-FU), cisplatin, and docetaxel as first-line treatment in patients with recurrent and/or metastatic squamous cell carcinoma…
2013
e17021 Background: This study investigates efficacy and toxicity of docetaxel added to cetuximab, cisplatin and 5-FU for patients with R/M SCCHN. We here report a planned second interim analysis to compare response rates between arms in order to decide on continuing to full accrual. Methods: Inclusion criteria were: stage III/IV R/M SCCHN and ECOG 0-1. Patients were randomized to arm A: cetuximab (standard dose) plus a maximum of 6 cycles of docetaxel (40 mg/m², day 1+8), cisplatin (40 mg/m², day 1+8) and 5-FU (2000 mg/m², day 1+8) or to arm B: cetuximab (standard dose), cisplatin (100 mg/m², day 1) and 5-FU (1000 mg/m², day 1-4). Treatment was administered until progression or intolerabil…
Bioaccessibility and decomposition of cylindrospermopsin in vegetables matrices after the application of an in vitro digestion model.
2018
Research on the human exposure to Cylindrospermopsin (CYN) via consumption of contaminated food is of great interest for risk assessment purposes. The aim of this work is to evaluate for the first time the CYN bioaccessibility in contaminated vegetables (uncooked lettuce and spinach, and boiled spinach) after an in vitro digestion model, including the salivar, gastric and duodenal phases and, colonic fermentation under lactic acid bacteria. The results obtained showed that the digestion processes are able to diminish CYN levels, mainly in the colonic phase, especially in combination with the boiling treatment, decreasing CYN levels in a significant way. Moreover, the potential decomposition…