Search results for "URACIL"

Could a variant structural form of thymidylate synthase gene of metastatic colorectal cancer patients be related with the poor response to 5 Fu treat…

2008

Background: Thymidylate synthase (TS) catalyzes methylation of dUMP to dTMP and is the target of 5-fluorouracil (5-Fu). TS levels vary considerably among tumors and the response to 5-FU is influenced by the intratumoral activity of the enzyme, with high levels generally being associated with a poor response. Response to 5-FU also depends on TS structure and some researchers showed that variant structural forms of TS in tumour cell lines confer resistance to fluoropyrimidines so the aim our study is to analyze the whole coding regions of the TS gene to evaluate a possible mechanism of 5 Fu resistance. Materials and Methods: We performed the TS-DNA gene sequence in 68 colorectal cancer (CRC) …

Pharmacological characterization of Uracil nucleotide-sensitive P2Y receptors in mouse ileum

2010

Since uracil nucleotide-preferring receptors, belonging to the P2Y receptor family and responding to either uridine triphosphate (UTP) or uridine diphosphate (UDP), have been proposed to be present at different cellular level in the gut, regulating various functions, we aimed to investigate whether their activation by uracil nucleotides may modulate the contractility of the intestinal muscle. Experiments were carried out in vitro, and the contractility of the longitudinal muscle from mouse ileum was recorded as changes of the isometric tension. UDP or UTP evoked a concentrationdependent, tetrodotoxin insensitive, contractile response. UDP effect was antagonized by suramin and by PPADS, P2 r…

Complete-active-space second-order perturbation theory (CASPT2//CASSCF) study of the dissociative electron attachment in canonical DNA nucleobases ca…

2015

Low-energy (0-3 eV) ballistic electrons originated during the irradiation of biological material can interact with DNA/RNA nucleobases yielding transient-anion species which undergo decompositions. Since the discovery that these reactions can eventually lead to strand breaking of the DNA chains, great efforts have been dedicated to their study. The main fragmentation at the 0-3 eV energy range is the ejection of a hydrogen atom from the specific nitrogen positions. In the present study, the methodological approach introduced in a previous work on uracil [I. González-Ramírez et al., J. Chem. Theory Comput. 8, 2769-2776 (2012)] is employed to study the DNA canonical nucleobases fragmentations…

An Open-Label Phase II Study Evaluating the Safety and Efficacy of Ramucirumab Combined With mFOLFOX-6 as First-Line Therapy for Metastatic Colorecta…

2014

Abstract Author Summary Background. Vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2) are believed to mediate angiogenesis in colorectal cancer (CRC). Ramucirumab (RAM; IMC-1121B) is a human IgG1 monoclonal antibody that inhibits VEGF ligand binding to VEGFR-2, inhibiting VEGFR-2 activation and signaling. Methods. Patients with metastatic CRC, Eastern Cooperative Oncology Group performance status 0–1, and adequate organ function who had not received chemotherapy for metastatic disease received RAM and the modified FOLFOX-6 regimen every 2 weeks. Endpoints included progression-free survival (PFS), objective response rate, overall survival, and safety. The sample size wa…

Neoadjuvant treatment for locally advanced unresectable and borderline resectable pancreatic cancer: oncological outcomes at a single academic centre.

2020

INTRODUCTION: Pancreatic cancer (PC), even in the absence of metastatic disease, has a dismal prognosis. One-third of them are borderline resectable (BRPC) or locally advanced unresectable PC (LAUPC) at diagnosis. There are limited prospective data supporting the best approach on these tumours. Neoadjuvant chemotherapy (ChT) is being increasingly used in this setting. METHODS: This is a retrospective series of consecutive patients staged as BRPC or LAUPC after discussion in the multidisciplinary board (MDB) at an academic centre. All received neoadjuvant ChT, followed by chemoradiation (ChRT) in some cases, and those achieving enough downstaging had a curative-intent surgery. Descriptive da…

New horizons for OSCC chemotherapy: transmucosal permeability of 5-fluorouracil throughout porcine buccal mucosa

2007

Efficacy of four cleaning solutions for the decontamination of selected cytotoxic drugs on the different surfaces of an automated compounding system

2018

The automated aseptic preparation of ready-to-administer antineoplastic drug solutions with robotic systems reduces the risk of occupational exposure. However, the surfaces in the preparation area of the robot are to be cleaned by wiping with an appropriate cleaning solution. The aim of the study was to evaluate the cleaning efficacy of four cleaning solutions on four surface materials installed in the APOTECAchemo robot. Predefined amounts of cisplatin (Cis), 5-fluorouracil (5-FU), and cyclophosphamide (CP) were intentionally spread on test plates made of stainless steel, aluminium, polyoxymethylene, and polycarbonate just as installed in the robotic system APOTECAchemo. After drying, the …

Interaction of 5‐fluorouracil with β‐cyclodextrin: A density functional theory study with dispersion correction

2020

Detailed studies on the stability, interaction, and microstructure of host‐guest complexes in the vacuum of 5‐fluorouracil (5FU) with β‐cyclodextrin (βCD) were performed using B3LYP with the inclusion of Grimme's dispersion correction GD3 term and 6‐31+G(d,p) basis set. Among several studied 1:1 5FU‐βCD complexes, the one placing the keto tautomer of 5FU vertically in the host cavity and forming N‐H···OCD and CO···HOCD hydrogen bonds with hydroxyl groups of the smaller rim of βCD has the highest stability (Eint = −195 kJ/mol). Interestingly, there are no interactions with the inner hydrophobic part of the βCD host cavity. The strength of the intermolecular H‐bonds to the smaller rim of βC…

Experimental and Theoretical Study of Dynamic Structural Transformations between Sensing Copper(II)-Uracil Antiferromagnetic and Metamagnetic Coordin…

2020

This paper describes the synthesis and characterization of several Copper(II)-uracil-1-propionic acid (UPrOH) coordination compounds, including the theoretical and experimental study of their cryst...

On the aromaticity of uracil and its 5-halogeno derivatives as revealed by theoretically derived geometric and magnetic indexes

2020

AbstractThe problem of aromaticity in heterocyclic rings of uracil and its 5-halogenoderivatives (5XU) was analyzed theoretically by calculating modified harmonic oscillator model of aromaticity (HOMA) for Heterocycle Electron Delocalization (HOMHED), nucleus-independent chemical shift parameters (NICS) and the so-called scan experiments, using helium-3 atom as a magnetic probe. The impact of halogen electronegativity on C5 atom’s NBO charges was also investigated. Water, as a polar environment, has a negligible impact on 5XU aromaticity. The most stable diketo tautomer shows a very low aromaticity while the “rare” dihydroxy form (tautomer No 6) is aromatic and resembles benzene. This is in…