Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 343
Filtrar
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 308: 123641, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38061108

RESUMEN

The binding mode of antineoplastic antimetabolite, floxuridine (FUDR), with human serum albumin (HSA), the leading carrier in blood circulation, was ascertained using multi-spectroscopic, microscopic, and computational techniques. A static fluorescence quenching was established due to decreased Ksv values with rising temperatures, suggesting FUDR-HSA complexation. UV-vis absorption spectral results also supported this conclusion. The binding constant, Ka values, were found within 9.7-7.9 × 103 M-1 at 290, 300, and 310 K, demonstrating a moderate binding affinity for the FUDR-HSA system. Thermodynamic data (ΔS = +46.35 J.mol-1.K-1 and ΔH = -8.77 kJ.mol-1) predicted the nature of stabilizing forces (hydrogen-bonds, hydrophobic, and van der Waals interactions) for the FUDR-HSA complex. Circular dichroism spectra displayed a minor disruption in the protein's 2° and 3° structures. At the same time, atomic force microscopy images proved variations in the FUDR-HSA surface morphology, confirming its complex formation. The protein's microenvironment around Trp/Tyr residues was also modified, as judged by 3-D fluorescence spectra. FUDR-bound HSA showed better resistance against thermal stress. As disclosed from ligand displacement studies, the FUDR binding site was placed in subdomain IIA (Site I). Further, the molecular docking analysis corroborated the competing displacement studies. Molecular dynamics evaluations revealed that the complex achieved equilibrium during simulations, confirming the FUDR-HSA complex's stability.


Asunto(s)
Floxuridina , Albúmina Sérica Humana , Humanos , Albúmina Sérica Humana/química , Floxuridina/metabolismo , Simulación del Acoplamiento Molecular , Unión Proteica , Espectrometría de Fluorescencia , Sitios de Unión , Dicroismo Circular , Termodinámica
2.
Mol Microbiol ; 117(5): 1089-1103, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35279884

RESUMEN

Reduced glutathione (GSH) plays an essential role in relieving oxidative insult from the generation of free radicals via normal physiological processes. However, GSH can be exploited by bacteria as a signalling molecule for the regulation of virulence. We describe findings arising from a serendipitous observation that when GSH and Escherichia coli were incubated with 5'fluorodeoxyuridine (FUdR)-synchronised populations of Caenorhabditis elegans, the nematodes underwent rapid death. Death was mediated by the production of hydrogen sulphide mainly through the action of tnaA, a tryptophanase-encoding gene in E. coli. Other Enterobacteriaceae species possess similar cysteine desulfhydrases that can catabolise l-cysteine-containing compounds to hydrogen sulphide and mediate nematode killing when worms had been pre-treated with FUdR. When colonic epithelial cell lines were infected, hydrogen sulphide produced by these bacteria in the presence of GSH was also able to inhibit ATP synthesis in these cells particularly when cells had been treated with FUdR. Therefore, bacterial production of hydrogen sulphide could act in concert with a commonly used genotoxic cancer drug to exert host cell impairment. Hydrogen sulphide also increases bacterial adhesion to the intestinal cells. These findings could have implications for patients undergoing chemotherapy using FUdR analogues that could result in intestinal damage.


Asunto(s)
Sulfuro de Hidrógeno , Animales , Bacterias/metabolismo , Caenorhabditis elegans/microbiología , Enterobacteriaceae/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Floxuridina/metabolismo , Glutatión/metabolismo , Humanos , Sulfuro de Hidrógeno/metabolismo , Sulfuro de Hidrógeno/farmacología
3.
Chem Commun (Camb) ; 57(100): 13768-13771, 2021 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-34859797

RESUMEN

A novel theranostic probe called CX-B-DF is constructed for precise chemotherapy guided by near-infrared (NIR) fluorescence imaging. Moreover, the theranostic probe shows high cytotoxicity to cancer cells under dual activation (H2O2 and TP), which causes the accuracy of drug release to be improved and the toxic side effects to be reduced.


Asunto(s)
Antineoplásicos/uso terapéutico , Ácidos Borónicos/uso terapéutico , Cumarinas/uso terapéutico , Floxuridina/uso terapéutico , Colorantes Fluorescentes/uso terapéutico , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/metabolismo , Ácidos Borónicos/metabolismo , Línea Celular Tumoral , Cumarinas/metabolismo , Floxuridina/metabolismo , Colorantes Fluorescentes/metabolismo , Células HEK293 , Humanos , Peróxido de Hidrógeno/metabolismo , Masculino , Ratones Endogámicos BALB C , Neoplasias/diagnóstico por imagen , Imagen Óptica , Medicina de Precisión , Timidina Fosforilasa/metabolismo
4.
Appl Microbiol Biotechnol ; 103(19): 7997-8008, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31414160

RESUMEN

The synthesis of rhamnosylated compounds has gained great importance since these compounds have potential therapeutic applications. The enzymatic approaches for glycosylation of bioactive molecules have been well developed; however, the enzymatic rhamnosylation has been largely hindered by lacking of the glycosyl donor for rhamnosyltransferases. Here, we employed an α-L-rhamnosidase from Alternaria sp. L1 (RhaL1) to perform one-step rhamnosylation of anticancer drugs, including 2'-deoxy-5-fluorouridine (FUDR), cytosine arabinoside (Ara C), and hydroxyurea (Hydrea). The key synthesis conditions including substrate concentrations and reaction time were carefully optimized, and the maximum yields of each rhamnosylated drugs were 57.7 mmol for rhamnosylated Ara C, 68.6 mmol for rhamnosylated Hydrea, and 42.2 mmol for rhamnosylated FUDR. It is worth pointing out that these rhamnosylated drugs exhibit little cytotoxic effects on cancer cells, but could efficiently restore cytotoxic activity when incubated with exogenous α-L-rhamnosidase, suggesting their potential applications in the enzyme-activated prodrug system. To evaluate the cancer-targeting ability of rhamnose moiety, the rhamnose-conjugated fluorescence dye rhodamine B (Rha-RhB) was constructed. The fluorescence probe Rha-RhB displayed much higher cell affinity and cellular internalization rate of oral cancer cell KB and breast cancer cell MDA-MB-231 than that of the normal epithelial cells MCF 10A, suggesting that the rhamnose moiety could mediate the specific internalization of rhamnosylated compounds into cancer cells, which greatly facilitated their applications for cancer-targeting drug delivery.


Asunto(s)
Alternaria/enzimología , Antineoplásicos/metabolismo , Glicósido Hidrolasas/metabolismo , Terapia Molecular Dirigida/métodos , Neoplasias/tratamiento farmacológico , Profármacos/metabolismo , Ramnosa/metabolismo , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Citarabina/metabolismo , Citarabina/farmacología , Floxuridina/metabolismo , Floxuridina/farmacología , Humanos , Hidroxiurea/metabolismo , Hidroxiurea/farmacología , Profármacos/farmacología
5.
Bioorg Med Chem Lett ; 29(11): 1304-1307, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30975626

RESUMEN

Among the various enzymes, reductases that catalyze one-electron reduction are involved in the selective activation of functional compounds or materials in hypoxia, which is one of the well-known pathophysiological characteristics of solid tumors. Enzymatic one-electron reduction has been recognized as a useful reaction that can be applied in the design of tumor hypoxia-targeting drugs. In this report, we characterized the enzymatic reaction of 5-fluorodeoxyuridine (FdUrd) prodrug bearing an indolequinone unit (IQ-FdUrd), which is a substrate of reductases. IQ-FdUrd was activated to release FdUrd under hypoxic conditions after treatment with cytochrome NADPH P450 reductase. We also confirmed that IQ-FdUrd showed selective cytotoxicity in hypoxic tumor cells.


Asunto(s)
Hipoxia de la Célula/efectos de los fármacos , Floxuridina/farmacología , Indolquinonas/farmacología , NADPH-Ferrihemoproteína Reductasa/metabolismo , Profármacos/farmacología , Relación Dosis-Respuesta a Droga , Activación Enzimática , Floxuridina/química , Floxuridina/metabolismo , Humanos , Indolquinonas/química , Indolquinonas/metabolismo , Estructura Molecular , NADP/metabolismo , Profármacos/química , Profármacos/metabolismo , Relación Estructura-Actividad
6.
Angew Chem Int Ed Engl ; 57(29): 8994-8997, 2018 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-29923269

RESUMEN

Automated attachment of chemotherapeutic drugs to oligonucleotides through phosphoramidite chemistry and DNA synthesis has emerged as a powerful technology in constructing structure-defined and payload-tunable oligonucleotide-drug conjugates. In practice, however, in vivo delivery of these oligonucleotides remains a challenge. Inspired by the systemic transport of hydrophobic payloads by serum albumin in nature, we report the development of a lipid-conjugated floxuridine homomeric oligonucleotide (LFU20) that "hitchhikes" with endogenous serum albumin for cancer chemotherapy. Upon intravenous injection, LFU20 immediately inserts into the hydrophobic cave of albumin to form an LFU20/albumin complex, which accumulates in the tumor by the enhanced permeability and retention (EPR) effect and internalizes into the lysosomes of cancer cells. After degradation, cytotoxic floxuridine monophosphate is released to inhibit cell proliferation.


Asunto(s)
Antimetabolitos Antineoplásicos/metabolismo , Antimetabolitos Antineoplásicos/farmacocinética , Sistemas de Liberación de Medicamentos , Floxuridina/análogos & derivados , Floxuridina/farmacocinética , Albúmina Sérica/metabolismo , Animales , Antimetabolitos Antineoplásicos/uso terapéutico , Floxuridina/metabolismo , Floxuridina/uso terapéutico , Interacciones Hidrofóbicas e Hidrofílicas , Ratones Desnudos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Oligonucleótidos/metabolismo , Oligonucleótidos/farmacocinética , Oligonucleótidos/uso terapéutico , Unión Proteica
7.
Gut ; 67(3): 497-507, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28077438

RESUMEN

OBJECTIVE: Desmoplasia and hypovascularity are thought to impede drug delivery in pancreatic ductal adenocarcinoma (PDAC). However, stromal depletion approaches have failed to show clinical responses in patients. Here, we aimed to revisit the role of the tumour microenvironment as a physical barrier for gemcitabine delivery. DESIGN: Gemcitabine metabolites were analysed in LSL-KrasG12D/+ ; LSL-Trp53R172H/+ ; Pdx-1-Cre (KPC) murine tumours and matched liver metastases, primary tumour cell lines, cancer-associated fibroblasts (CAFs) and pancreatic stellate cells (PSCs) by liquid chromatography-mass spectrometry/mass spectrometry. Functional and preclinical experiments, as well as expression analysis of stromal markers and gemcitabine metabolism pathways were performed in murine and human specimen to investigate the preclinical implications and the mechanism of gemcitabine accumulation. RESULTS: Gemcitabine accumulation was significantly enhanced in fibroblast-rich tumours compared with liver metastases and normal liver. In vitro, significantly increased concentrations of activated 2',2'-difluorodeoxycytidine-5'-triphosphate (dFdCTP) and greatly reduced amounts of the inactive gemcitabine metabolite 2',2'-difluorodeoxyuridine were detected in PSCs and CAFs. Mechanistically, key metabolic enzymes involved in gemcitabine inactivation such as hydrolytic cytosolic 5'-nucleotidases (Nt5c1A, Nt5c3) were expressed at low levels in CAFs in vitro and in vivo, and recombinant expression of Nt5c1A resulted in decreased intracellular dFdCTP concentrations in vitro. Moreover, gemcitabine treatment in KPC mice reduced the number of liver metastases by >50%. CONCLUSIONS: Our findings suggest that fibroblast drug scavenging may contribute to the clinical failure of gemcitabine in desmoplastic PDAC. Metabolic targeting of CAFs may thus be a promising strategy to enhance the antiproliferative effects of gemcitabine.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacocinética , Carcinoma Ductal Pancreático/metabolismo , Desoxicitidina/análogos & derivados , Fibroblastos/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Pancreáticas/metabolismo , 5'-Nucleotidasa/metabolismo , Actinas/metabolismo , Animales , Antimetabolitos Antineoplásicos/uso terapéutico , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/secundario , Línea Celular Tumoral , Citidina Trifosfato/análogos & derivados , Citidina Trifosfato/metabolismo , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapéutico , Floxuridina/análogos & derivados , Floxuridina/metabolismo , Humanos , Hígado/metabolismo , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Ratones , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/patología , Cultivo Primario de Células , Microambiente Tumoral , Gemcitabina
8.
Biochim Biophys Acta Gen Subj ; 1862(3): 485-494, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29107813

RESUMEN

We report, based on biophysical studies and molecular mechanical calculations that curcumin binds DNA hairpin in the minor groove adjacent to the loop region forming a stable complex. UV-Vis and fluorescence spectroscopy indicated interaction of curcumin with DNA hairpin. In this novel binding motif, two É£ H of curcumin heptadiene chain are closely positioned to the A16-H8 and A17-H8, while G12-H8 is located in the close proximity of curcumin α H. Molecular dynamics (MD) simulations suggest, the complex is stabilized by noncovalent forces including; π-π stacking, H-bonding and hydrophobic interactions. Nuclear magnetic resonance (NMR) spectroscopy in combination with molecular dynamics simulations indicated curcumin is bound in the minor groove, while circular dichroism (CD) spectra suggested minute enhancement in base stacking and a little change in DNA helicity, without significant conformational change of DNA hairpin structure. The DNA:curcumin complex formed with FdU nucleotides rather than Thymidine, demonstrated enhanced cytotoxicity towards oral cancer cells relative to the only FdU substituted hairpin. Fluorescence co-localization demonstrated stability of the complex in biologically relevant conditions, including its cellular uptake. Acridine orange/EtBr staining further confirmed the enhanced cytotoxic effects of the complex, suggesting apoptosis as mode of cell death. Thus, curcumin can be noncovalently complexed to small DNA hairpin for cellular delivery and the complex showed increased cytotoxicity in combination with FdU nucleotides, demonstrating its potential for advanced cancer therapy.


Asunto(s)
Anticarcinógenos/farmacología , Antineoplásicos Fitogénicos/farmacología , Curcumina/farmacología , ADN/efectos de los fármacos , Floxuridina/farmacología , Anticarcinógenos/química , Antineoplásicos Fitogénicos/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Dicroismo Circular , Curcumina/química , Sinergismo Farmacológico , Floxuridina/metabolismo , Humanos , Modelos Moleculares , Simulación de Dinámica Molecular , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido Nucleico/efectos de los fármacos , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta
9.
Biotechnol Lett ; 39(12): 1903-1910, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28871515

RESUMEN

OBJECTIVE: To isolate a thermostable pyrimidine nucleoside phosphorylase (PyNP) from mesophilic bacteria by gene mining. RESULTS: BbPyNP from Brevibacillus borstelensis LK01 was isolated by gene mining. BbPyNP had a highest 60% identity with that of reported PyNPs. BbPyNP could catalyze the phosphorolysis of thymidine, 2'-deoxyuridine, uridine and 5-methyuridine. BbPyNP had good thermostability and retained 73% of its original activity after 2 h incubation at 50 °C. BbPyNP had the highest activity at an optimum alkaline pH of 8.5. BbPyNP was stable from pH 7 to 9.8. Under preliminary optimized conditions, the biosynthesis of various 5-halogenated pyrimidine nucleosides by BbPyNP reached the yield of 61-84%. CONCLUSION: An efficient approach was estimated in isolating thermostable PyNP from mesophilic bacteria.


Asunto(s)
Brevibacillus/genética , Floxuridina/metabolismo , Ingeniería Metabólica/métodos , Nucleósidos/metabolismo , Pirimidina Fosforilasas/metabolismo , Brevibacillus/enzimología , Estabilidad de Enzimas , Escherichia coli/genética , Floxuridina/análisis , Calor , Concentración de Iones de Hidrógeno , Nucleósidos/química , Pirimidina Fosforilasas/química , Pirimidina Fosforilasas/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
10.
J Colloid Interface Sci ; 507: 217-224, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-28800445

RESUMEN

Development of gemcitabine (GEM) nanocarriers as theranostic agents for pancreatic cancer chemotherapy has received extensive attention in recent years. A novel enzyme-sensitive albumin-based GEM delivery nanoplatform was developed in this research by simple conjugation of GEM to human serum albumin (HSA) via cathepsin B cleavable peptide GFLG and then complexing with near-infrared (NIR) dye IR780, forming a HSA-GEM/IR780 complex. The successful preparation of HSA-GEM/IR780 complex was confirmed by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS), UV-vis-NIR absorption spectra and fluorescent emission spectra. The in vivo performance of HSA-GEM/IR780 complex was carried out on BxPC-3 pancreatic tumor xenografted mice. As revealed by in vivo NIR imaging, HSA-GEM/IR780 exhibited enhanced accumulation and long-term retention in tumor tissues compared to free IR780. Meanwhile, compared to free GEM, the deamination of GEM nanovectors into inactive 2',2'-difluorodeoxyuridine (dFdU) can be greatly suppressed, while the concentration of the activated form of GEM (gemcitabine triphosphate, dFdCTP) was significantly increased in tumor tissue, thus exhibiting superior tumor inhibition activity with minimal side effects.


Asunto(s)
Albúminas/química , Antineoplásicos/química , Desoxicitidina/análogos & derivados , Portadores de Fármacos/química , Nanopartículas/química , Neoplasias Pancreáticas/tratamiento farmacológico , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Desoxicitidina/química , Desoxicitidina/farmacocinética , Desoxicitidina/uso terapéutico , Liberación de Fármacos , Floxuridina/análogos & derivados , Floxuridina/metabolismo , Colorantes Fluorescentes , Xenoinjertos , Humanos , Indoles/química , Ratones Endogámicos BALB C , Oligopéptidos/química , Tamaño de la Partícula , Propiedades de Superficie , Nanomedicina Teranóstica , Distribución Tisular , Gemcitabina
11.
Nucleosides Nucleotides Nucleic Acids ; 35(10-12): 652-662, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27906622

RESUMEN

Antimetabolites are incorporated into DNA and RNA, affecting their function. Liquid-chromatography-mass-spectrometry (LC-MS-MS) permits the sensitive, selective analysis of normal nucleosides. The method was adapted to measure the incorporation of deoxyuridine, gemcitabine (difluorodeoxycytidine), its metabolite difluorodeoxyuridine (dFdU), and the novel compound fluorocyclopentenylcytosine (RX3117). DNA was degraded to its deoxynucleotides for quantification by LC-MS-MS, gradient chromatography on a Phenomenex prodigy-3-ODS with positive ionization. The range of deoxyuridine DNA-mis-incorporation varied nine-fold in 27 cell lines (leukemia, colon, ovarian, lung cancer). At low-folate conditions a 2.1-fold increase in deoxyuridine was observed. Global methylation (given as % 5-methyl-deoxycytidine) was comparable between the cell lines (4.6-6.5%). Exposure of A2780 cells to 1 µM gemcitabine (4 hours) resulted in 3.6 pmol gemcitabine/µg DNA, but in AG6000 cells (deoxycytidine-kinase-deficient) no incorporation was found. However, when A2780, AG6000, or CCRF-CEM cells were exposed to 100 µM dFdU we found it as gemcitabine, 20.5, 19.6, and 0.51 pmol gemcitabine/µg DNA, respectively. Preincubation of CCRF-CEM cells with cyclopentenyl-cytosine (a CTP-synthetase inhibitor) increased dFdU incorporation four-fold. Apparently dFdU is activated independently of deoxycytidine-kinase and possibly converted in-situ to dFdCMP. RX3117 was incorporated into both DNA and RNA (0.0037 and 0.00515 pmol/µg, respectively). In summary, a sensitive method to quantify the incorporation of gemcitabine, deoxyuridine, and RX-3117 was developed, which revealed that dFdU was incorporated into DNA as the parent compound gemcitabine.


Asunto(s)
Citidina/análogos & derivados , Metilación de ADN , Desoxicitidina/análogos & derivados , Floxuridina/metabolismo , Línea Celular Tumoral , Cromatografía Liquida , Citidina/metabolismo , ADN/metabolismo , Desoxicitidina/metabolismo , Humanos , Límite de Detección , Espectrometría de Masas , ARN/metabolismo , Gemcitabina
12.
Cancer Chemother Pharmacol ; 76(5): 1081-91, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26242222

RESUMEN

PURPOSE: To describe concentration versus time profiles of capecitabine and its metabolites 5'-DFUR, 5'-DFCR and 5-FU, depending on tablet formulation and on frequent and/or relevant genetic polymorphisms of cytidine deaminase, dihydropyrimidine dehydrogenase, thymidylate synthase and methylenetetrahydrofolate reductase (MTHFR). METHODS: In 46 cancer patients on chronic capecitabine treatment, who voluntarily participated in the study, individual therapeutic doses were replaced on four consecutive mornings by the study medication. The appropriate number of 500 mg test (T) or reference (R) capecitabine tablets was given in randomly allocated sequences TRTR or RTRT (replicate design). Average bioavailability was assessed by ANOVA. RESULTS: Thirty female and 16 male patients suffering from gastrointestinal or breast cancer (mean age 53.4 years; mean dose 1739 mg) were included. The T/R ratios for AUC0-t(last) and C max were 96.7 % (98 % CI 90.7-103.2 %) and 87.2 % (98 % CI 74.9-101.5 %), respectively. Within-subject variability for AUC0-t(last) and C max (coefficient of variation for R) was 16.5 and 30.2 %, respectively. Similar results were seen for all metabolites. No serious adverse events occurred. For the MTHFR C677T (rs1801133) genotype, an increasing number of 677C alleles showed borderline correlation with an increasing elimination half-life of capecitabine (p = 0.043). CONCLUSIONS: The extent of absorption was similar for T and R, but the rate of absorption was slightly lower for T. While such differences are not considered as clinically relevant, formal bioequivalence criteria were missed. A possible, probably indirect role of the MTHFR genotype in pharmacokinetics of capecitabine and/or 5-FU should be investigated in further studies.


Asunto(s)
Activación Metabólica/genética , Antimetabolitos Antineoplásicos/farmacocinética , Capecitabina/farmacocinética , Citidina Desaminasa/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Profármacos/farmacocinética , Timidilato Sintasa/genética , Administración Oral , Adulto , Anciano , Alelos , Antimetabolitos Antineoplásicos/administración & dosificación , Área Bajo la Curva , Capecitabina/administración & dosificación , Carboxilesterasa/metabolismo , Citidina Desaminasa/metabolismo , Desoxicitidina/análogos & derivados , Desoxicitidina/metabolismo , Dihidrouracilo Deshidrogenasa (NADP)/genética , Dihidrouracilo Deshidrogenasa (NADP)/metabolismo , Femenino , Floxuridina/metabolismo , Fluorouracilo/metabolismo , Genotipo , Humanos , Hígado/enzimología , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/metabolismo , Persona de Mediana Edad , Proteínas de Neoplasias/metabolismo , Polimorfismo de Nucleótido Simple , Profármacos/administración & dosificación , Comprimidos , Equivalencia Terapéutica , Timidina Fosforilasa/metabolismo , Timidilato Sintasa/metabolismo
13.
J Pharm Biomed Anal ; 110: 58-66, 2015 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-25804433

RESUMEN

5-Fluorouracil (5-FU) and its oral prodrug capecitabine are among the most widely used chemotherapeutics. For cytotoxic activity, 5-FU requires cellular uptake and intracellular metabolic activation. Three intracellular formed metabolites are responsible for the antineoplastic effect of 5-FU: 5-fluorouridine 5'-triphosphate (FUTP), 5-fluoro-2'-deoxyuridine 5'-triphosphate (FdUTP) and 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP). In this paper, we describe the development of an LC-MS/MS assay for quantification of these active 5-FU nucleotides in peripheral blood mononuclear cells (PBMCs). Because the intracellular 5-FU nucleotide concentrations were very low, maximization of the release from the cell matrix and minimization of interference were critical factors. Therefore, a series of experiments was performed to select the best method for cell lysis and nucleotide extraction. Chromatography was optimized to obtain separation from endogenous nucleotides, and the effect of different cell numbers was examined. The assay was validated for the following concentration ranges in PBMC lysate: 0.488-19.9 nM for FUTP, 1.66-67.7 nM for FdUTP and 0.748-30.7 nM for FdUMP. Accuracies were between -2.2 and 7.0% deviation for all analytes, and the coefficient of variation values were ≤ 4.9%. The assay was successfully applied to quantify 5-FU nucleotides in PBMC samples from patients treated with capecitabine and patients receiving 5-FU intravenously. FUTP amounts up to 3054 fmol/10(6) PBMCs and FdUMP levels up to 169 fmol/10(6) PBMCs were measured. The FdUTP concentrations were below the lower limit of quantification. To our knowledge, this is the first time that 5-FU nucleotides were quantified in cells from patients treated with 5-FU or capecitabine without using a radiolabel.


Asunto(s)
Antineoplásicos/metabolismo , Cromatografía Liquida , Monitoreo de Drogas/métodos , Fluorouracilo/metabolismo , Leucocitos Mononucleares/metabolismo , Espectrometría de Masas en Tándem , Antineoplásicos/farmacocinética , Transporte Biológico , Biotransformación , Calibración , Cromatografía Liquida/normas , Nucleótidos de Desoxiuracil/metabolismo , Monitoreo de Drogas/normas , Floxuridina/análogos & derivados , Floxuridina/metabolismo , Fluorodesoxiuridilato/metabolismo , Fluorouracilo/farmacocinética , Humanos , Modelos Lineales , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/normas , Uridina Trifosfato/análogos & derivados , Uridina Trifosfato/metabolismo
14.
Biosens Bioelectron ; 68: 322-328, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-25599844

RESUMEN

In this work, an in vitro liver model in a microfluidic device to imitate and detect prodrug metabolism was developed. A widely used prodrug capecitabine (CAP), which needs to be metabolized into active intermediate in the liver and then transformed into final effective drug in tumor cells, was selected as a model compound. The microfluidic device we exploited consists of a cell co-culture section, in which HepG2 cells were cultured to represent liver while MCF-7 cells were used to represent the tumor tissue, and an on-line solid phase extraction (SPE) section connecting to the ionization source of the ESI-Q-TOF mass spectrometer. The prodrug metabolism was realized and confirmed within this in vitro liver model as the intermediate product of the prodrug 5'-deoxy-5-fluorouridine (DFUR) was successfully detected with MS after the conditioning of HepG2 cells, and the anti-tumor effect of the active metabolite was observed through cell vitality assays of MCF-7 cells. The limit of detection (LOD) using on-chip SPE was at 10nM and semi-quantitative analysis could be realized. This system has been proved useful and practical, showing a potential to replace conventional drug screening methods.


Asunto(s)
Antimetabolitos Antineoplásicos/metabolismo , Técnicas Biosensibles/instrumentación , Capecitabina/metabolismo , Floxuridina/metabolismo , Dispositivos Laboratorio en un Chip , Hígado/metabolismo , Antimetabolitos Antineoplásicos/análisis , Antimetabolitos Antineoplásicos/farmacología , Capecitabina/análisis , Capecitabina/farmacología , Supervivencia Celular/efectos de los fármacos , Técnicas de Cocultivo/instrumentación , Diseño de Equipo , Floxuridina/análisis , Floxuridina/farmacología , Células Hep G2 , Humanos , Células MCF-7 , Profármacos/análisis , Profármacos/metabolismo , Profármacos/farmacología , Extracción en Fase Sólida/instrumentación , Espectrometría de Masa por Ionización de Electrospray/instrumentación
15.
Salud pública Méx ; 56(6): 619-624, nov.-dic. 2014. ilus, tab
Artículo en Español | LILACS | ID: lil-733340

RESUMEN

Objetivo. Conocer la seroprevalencia y detección de infección primaria por citomegalovirus (CMV) mediante prueba de avidez de inmunoglobulina G (IgG) durante el primer trimestre del embarazo en el Hospital General de Morelia, Michoacán. Material y métodos. Se estudiaron 177 pacientes mediante prueba de Elisa modificada, la cual utiliza inmunoanálisis quimioluminiscente de micropartículas (CMIA) para detección de anti-CMV (IgG e inmunoglobulina M [IgM]) e IgG avidez. Resultados. Del total de pruebas, 90.4% resultaron positivas para IgG; de éstas, 2.3% resultaron reactivas a IgM. En este segundo grupo, la prueba de IgG avidez reportó avidez baja en 1.1% y alta en el mismo porcentaje; 9.6% fueron seronegativas. Conclusiones. Se encontró similitud con lo publicado en México. Los profesionales de la salud deben conocer los algoritmos para el diagnóstico y manejo oportuno de la infección por CMV mediante la prueba de avidez de IgG.


Objective. To determine the seroprevalence and detection of primary infection by cytomegalovirus (CMV) with immunoglobulin G (IgG) avidity test during the first quarter of pregnancy in the General Hospital in Morelia, Michoacan. Materials and methods. A total of 177 patients were studied employing a modified Elisa test using a chemiluminescent microparticle immunoassay (CMIA) for the detection of CMV antibodies (IgG and immunoglobulin M [IgM]), and IgG avidity. Results. 90.4% were positive for IgG, and of these, 2.3% were also reactive for IgM, and in this group the IgG avidity test reported low avidity for 1.1% and higher avidity in the same percentage. 9.6% were seronegative. Conclusions. Similarity was found with published studies in Mexico. Health professionals should know the clinical algorithms for diagnosis and proper management of CMV infection using the IgG avidity test.


Asunto(s)
Animales , Humanos , Masculino , Ratones , Anticuerpos Monoclonales/inmunología , Neoplasias/enzimología , Timidina Fosforilasa/análisis , Ensayo de Inmunoadsorción Enzimática , Floxuridina/metabolismo , Fluorouracilo/metabolismo , Ratones Endogámicos BALB C , Timidina Fosforilasa/inmunología , Timidina Fosforilasa/aislamiento & purificación
16.
Rev. bras. enferm ; 67(6): 987-993, Nov-Dec/2014. tab, graf
Artículo en Portugués | LILACS, BDENF | ID: lil-732824

RESUMEN

Objetivo: Identificar na literatura indicações e controvérsias do ATP bioluminescência para avaliação da efetividade da limpeza de superfícies em estabelecimentos de saúde. Método: Revisão integrativa da literatura, entre 2000 e 2012, nas bases de dados MEDLINE, LILACS, Science Direct, SCOPUS e Isi Web of Knowledge. Resultados: Selecionou-se para esta revisão 15 artigos. O ATP bioluminescência foi apontado como importante recurso educacional e método complementar à inspeção visual e às análises microbiológicas na avaliação da efetividade da limpeza. A impossibilidade de indicar a contaminação da superfície por micro-organismos viáveis, a interferência por substâncias químicas e a dificuldade de interpretação dos resultados constituem as principais controvérsias para o uso deste nos serviços de saúde. Conclusão: Apesar de constituir importante recurso na avaliação da limpeza de superfícies, mais estudos são necessários para incorporação efetiva do método nos serviços de saúde. .


Objective: To identify indications and controversies in the literature of the use of ATP bioluminescence to evaluate the effectiveness of surface cleaning in healthcare facilities. Method: Integrative literature review between 2000 and 2012 in the following databases: MEDLINE, LILACS, Science Direct, SCOPUS and Isi Web of Knowledge. Results: were selected for this review 15 articles. The ATP bioluminescence was considered an important educational resource and complementary method to visual inspection and microbiological evaluation of the effectiveness of cleaning. The impossibility to indicate surface contamination by microorganisms, interference by chemicals and the difficulty of interpreting the results constitute the main controversies in the use of ATP in health services. Conclusion: Although this is an important resource in the evaluation of surface cleaning, more studies are necessary for effective incorporation of the method in health services. .


Objetivo: Identificar en la literatura las indicaciones y controversias sobre el uso de la bioluminiscencia ATP para evaluar la eficacia de la limpieza de superficies en los servicios de salud. Método: Revisión integrativa de la literatura, entre 2000 y 2012, en las siguientes bases de datos: MEDLINE, LILACS, Science Direct, SCOPUS e ISI Web of Knowledge. Resultados: Se seleccionaron para esta revisión 15 artículos. La bioluminiscencia del ATP se considera un importante recurso educativo y método complementario a la inspección visual y la análisis microbiológica de la evaluación de la efectividad de la limpieza. La imposibilidad de indicar contaminación de la superficie por los microorganismos, la interferencia por los productos químicos y la dificultad de interpretar los resultados constituyen las principales controversias en la utilización de ATP en los servicios de salud. Conclusión: Aunque esto es un elemento importante en la evaluación de limpieza de superficies, se necesitan más estudios para incorporación eficaz del método en los servicios de salud. .


Asunto(s)
Animales , Masculino , Ratones , Antineoplásicos/farmacología , Desoxicitidina/análogos & derivados , Floxuridina/farmacología , Intestinos/efectos de los fármacos , Profármacos/farmacología , Desoxicitidina/farmacología , Floxuridina/metabolismo , Floxuridina/toxicidad , Fluorouracilo/metabolismo , Fluorouracilo/farmacología , Fluorouracilo/toxicidad , Ratones Endogámicos , Neoplasias Experimentales/tratamiento farmacológico , Profármacos/toxicidad
17.
Rev. latinoam. enferm ; 22(6): 911-917, 16/12/2014. tab
Artículo en Inglés | LILACS, BDENF | ID: lil-732936

RESUMEN

OBJECTIVE: to assess the quality of life of chronic kidney patients undergoing hemodialysis, using the WHOQOL-bref and WHOQOL-SRPB. METHOD: a descriptive and cross-sectional study was undertaken at a kidney replacement therapy service in the interior of the state of SP. The 110subjects who complied with the inclusion criteria answered the Subject Characterization Instrument, the WHOQOL-bref and WHOQOL-SRPB. RESULTS: most of the respondents were male (67.27%), with a mean age of 55.65 years, Catholic (55.45%), with unfinished primary education (33.64%) and without formal occupation (79.08%). The WHOQOL-bref domains with the highest and lowest mean score were, respectively, "psychological" (µ=74.20) and "physical" (µ=61.14). The WHOQOL-SRPB domains with the highest and lowest mean score were, respectively, "completeness and integration" (µ=4.00) and "faith" (µ=4.40). CONCLUSIONS: the respondents showed high quality of life scores, specifically in the dimensions related to spirituality, religion and personal beliefs. Losses were evidenced in the physical domain of quality of life, possibly due to the changes resulting from the chronic kidney disease and hemodialysis treatment. .


OBJETIVO: avaliar a qualidade de vida de pacientes renais crônicos em hemodiálise, por meio do WHOQOL-bref e WHOQOL-Spirituality, Religion and Personal Beliefs. MÉTODO: trata-se de um estudo descritivo, de corte transversal, realizado em uma unidade de terapia renal substitutiva do interior do Estado de São Paulo. Os 110 sujeitos que atenderam os critérios de inclusão responderam ao Instrumento de Caracterização dos Sujeitos, ao WHOQOL-bref e WHOQOL-Spirituality, Religion and Personal Beliefs. RESULTADOS: a maioria dos respondentes era do sexo masculino (67,27%), com idade média de 55,65 anos, católica (55,45%), com ensino fundamental incompleto (33,64%) e sem ocupação formal (79,08%). Os domínios do WHOQOL-bref com maior e menor pontuação média foram, respectivamente, "psicológico" (µ=74,20) e "físico" (µ=61,14). Os domínios do WHOQOL-Spirituality, Religion and Personal Beliefs de menor e maior pontuação média foram, respectivamente, "totalidade e integração" (µ=4,00) e "fé" (µ=4,40). CONCLUSÕES: os respondentes apresentaram elevados escores de qualidade de vida, especificamente nas dimensões referentes à espiritualidade, religião e crenças pessoais. Evidenciaram-se prejuízos no domínio físico da qualidade de vida, possivelmente em decorrência das alterações resultantes da doença renal crônica e do tratamento hemodialítico. .


OBJETIVO: evaluar la calidad de vida de pacientes renales crónicos en hemodiálisis, por medio del WHOQOL-bref y WHOQOL-SRPB. MÉTODO: se trata de un estudio descriptivo, de corte transversal, realizado en una unidad de terapia renal substitutiva del interior del estado de SP. Los 110 sujetos que atendieron a los criterios de inclusión respondieron al Instrumento de Caracterización de los Sujetos, al WHOQOL-bref y WHOQOL-SRPB. RESULTADOS: la mayoría de los entrevistados era del sexo masculino (67,27%), con edad promedio de 55,65 años, católicos (55,45%), con enseñanza fundamental incompleta (33,64%) y sin ocupación formal (79,08%). Los dominios del WHOQOL-bref con mayor y menor puntuación promedio fueron, respectivamente: "psicológico" (µ=74,20) y "físico" (µ=61,14). Los dominios del WHOQOL-SRPB de menor y mayor puntuación promedio fueron, respectivamente: "totalidad e integración" (µ=4,00) y "fe" (µ=4,40). CONCLUSIONES: los entrevistados presentaron elevados puntajes de calidad de vida, específicamente en las dimensiones referentes a espiritualidad, religión y creencias personales. Se evidenciaron perjuicios en el dominio físico de la calidad de vida, posiblemente en consecuencia de las alteraciones resultantes de la enfermedad renal crónica y del tratamiento de hemodiálisis. .


Asunto(s)
Humanos , Antineoplásicos/efectos adversos , Médula Ósea/efectos de los fármacos , Floxuridina/efectos adversos , Administración Oral , Antineoplásicos/administración & dosificación , Antineoplásicos/metabolismo , Sistema Nervioso Central/efectos de los fármacos , Floxuridina/administración & dosificación , Floxuridina/metabolismo , Corazón/efectos de los fármacos , Infusiones Intravenosas , Leucopenia/inducido químicamente , Trombocitopenia/inducido químicamente
18.
Salud pública Méx ; 56(4): 371-378, jul.-ago. 2014. ilus, tab
Artículo en Inglés | LILACS | ID: lil-733302

RESUMEN

Objective. To evaluate the modification effect of socioeconomic status (SES) on the association between acute exposure to particulate matter less than 10 microns in aerodynamic diameter (PM10) and mortality in Bogota, Colombia. Materials and methods. A time-series ecological study was conducted (1998-2006). The localities of the cities were stratified using principal components analysis, creating three levels of aggregation that allowed for the evaluation of the impact of SES on the relationship between mortality and air pollution. Results. For all ages, the change in the mortality risk for all causes was 0.76% (95%CI 0.27-1.26) for SES I (low), 0.58% (95%CI 0.16-1.00) for SES II (mid) and -0.29% (95%CI -1.16-0.57) for SES III (high) per 10µg/m³ increment in the daily average of PM10 on day of death. Conclusions. The results suggest that SES significantly modifies the effect of environmental exposure to PM10 on mortality from all causes and respiratory causes.


Objetivo. Evaluar el efecto modificador del nivel socioeconómico (NSE) sobre la asociación entre la exposición aguda a partículas menores de 10 micras de diámetro aerodinámico (PM10) y la mortalidad en Bogotá, Colombia. Material y métodos. Se realizó un estudio ecológico de series de tiempo (1998-2006). Mediante análisis de componentes principales se estableció una estratificación de las localidades de la ciudad, de lo que se generaron tres niveles de agregación que permitieron evaluar el impacto de la variable NSE en la relación mortalidad-contaminación atmosférica. Resultados. En todas las edades, para la mortalidad por todas las causas, el porcentaje de cambio en el riesgo fue 0.76% (IC95% 0.27-1.26) en el NSE I (bajo), 0.58% (IC95% 0.16-1.00) en el NSE II (medio) y -0.29% (IC95% -1.16-0.57) en el NSE III (alto), por incremento de 10µg/m³ en el promedio diario de PM10 en el día del deceso. Conclusiones. Los resultados sugieren que el NSE modifica de manera significativa el efecto de la exposición ambiental a PM10 sobre la mortalidad por todas las causas y causas respiratorias.


Asunto(s)
Humanos , Antineoplásicos/metabolismo , Floxuridina/análogos & derivados , Floxuridina/sangre , Floxuridina/metabolismo , Profármacos/metabolismo , Cromatografía Líquida de Alta Presión , Floxuridina/administración & dosificación , Floxuridina/química , Floxuridina/síntesis química , Cromatografía de Gases y Espectrometría de Masas , Neoplasias/sangre , Neoplasias/tratamiento farmacológico , Estándares de Referencia
19.
Biochem Cell Biol ; 91(6): 419-27, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24219283

RESUMEN

The goal of this study was to understand roles of nucleoside and nucleobase transport processes in capecitabine pharmacology in cells derived from human renal proximal tubule cells (hRPTCs) and three human renal cell carcinoma (RCC) cell lines, A498, A704, and Caki-1. Human equilibrative nucleoside transporters 1 and 2 (hENT1 and hENT2) mediated activities and a sodium-independent nucleobase activity were present in hRPTCs. In hRPTCs, uptake of 5'-deoxy-5-fluorouridine (DFUR), a nucleoside metabolite of capecitabine, was pH dependent with highest uptake seen at pH 6.0. In RCC cell lines, hENT1 was the major nucleoside transporter. Nucleobase transport activity was variable among the three RCC cell lines, with Caki-1 showing the highest and A498 showing the lowest activities. Treatment of RCC cell lines with interferon alpha (IFN-α) increased thymidine phosphorylase levels and prior treatment of RCC cell lines with IFN-α followed by 5-FU or DFUR resulted in enhanced sensitivity of all cell lines to 5-FU and two of three cell lines to DFUR. We report for the first time a nucleobase transport activity in hRPTCs and RCC cell lines. In addition, our in vitro cytotoxicity results showed that RCC cell lines differed in their response to 5-FU and DFUR and prior treatment with IFN-α potentiated cytotoxic response to metabolites of capecitabine.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Desoxicitidina/análogos & derivados , Floxuridina/farmacología , Fluorouracilo/análogos & derivados , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Túbulos Renales Proximales/efectos de los fármacos , Antimetabolitos Antineoplásicos/metabolismo , Transporte Biológico/efectos de los fármacos , Biotransformación , Capecitabina , Línea Celular Tumoral , Desoxicitidina/metabolismo , Desoxicitidina/farmacología , Tranportador Equilibrativo 1 de Nucleósido/genética , Tranportador Equilibrativo 1 de Nucleósido/metabolismo , Transportador Equilibrativo 2 de Nucleósido , Floxuridina/metabolismo , Fluorouracilo/metabolismo , Fluorouracilo/farmacología , Humanos , Concentración de Iones de Hidrógeno , Interferón-alfa/farmacología , Túbulos Renales Proximales/metabolismo , Túbulos Renales Proximales/patología , Cinética , Nucleósidos/metabolismo , Transducción de Señal , Timidina Fosforilasa/genética , Timidina Fosforilasa/metabolismo
20.
Zhonghua Wai Ke Za Zhi ; 51(7): 636-40, 2013 Jul.
Artículo en Chino | MEDLINE | ID: mdl-24256592

RESUMEN

OBJECTIVES: To study the change of ability to transform from 5'-deoxy-fluorouracil monophosphate (5'-DFUR) to fluorouracil (5-FU) in human colon cancer cell lines SW480 and LOVO which transfected with thymidine phosphorylase (TP) gene. And to discuss the anti-cancer activity of 5'-DFUR to SW480 and LOVO cells. METHODS: TP cDNA were transfected into human colorectal cancer cell lines SW480 and LOVO with the lentiviral vector, pLenti6.3_MCS_IRES2-EGFP. The transfection efficiency was analyzed by flow cytometer, the mRNA expression of TP was detected by RT-PCR, and the TP protein expression was detected by Western blot, and the volumes of 5-FU converted from 5'-DFUR both in 2 cells and medium were detected by high performance liquid chromatography (HPLC). The 50% inhibitory concentration (IC50) of 5'-DFUR on these 2 colon cancer cell lines both wild type and TP-transfected cells were evaluated by MTT assay. RESULTS: The colorectal cancer cell lines SW480 and LOVO transfected with human TP cDNA were monitored 5 generations, and the transfections efficiency rate wea about 95%. Compared with wild type cell SW480 and LOVO, the RQ values of mRNA expression of SW480-TP and LOVO-TP were (695 ± 171) folds (t = -7.00, P = 0.002) and (282 ± 87) folds (t = -5.61, P = 0.030), respectively. Also TP protein expression in SW480-TP and LOVO-TP were higher than their parent cells shown by Western blot. The volume of 5-FU converted from 5'-DFUR in the medium cultured SW480-TP and LOVO-TP were increased compared with their parent cells, respectively (t = 19.406-66.921, P < 0.01), whereas few of 5-FU was detected both in wild, and TP-transfected cells. After transfected with TP cDNA, the IC50 of 5'-DFUR on SW480-TP and LOVO-TP were (587 ± 17) µmol/L and (1088 ± 89) µmol/L respectively, and there were significantly less than their parent cells (t = -32.59 and -8.52, P < 0.01). CONCLUSIONS: The stabilized transfections of SW480 and LOVO with higher TP expression could be built with lentiviral vector. Transfected TP cDNA into SW480 and LOVO, could improve the expression both of TP mRNA and TP protein, increase the volume of 5-FU converted from 5'-DFUR in medium, and result in an enhancement of anticancer effect on these 2 cells.


Asunto(s)
Neoplasias del Colon/patología , Floxuridina/metabolismo , Timidina Fosforilasa/genética , Línea Celular Tumoral , Fluorouracilo/metabolismo , Humanos , Transcripción Genética , Transfección
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...