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1.
Environ Sci Technol ; 46(5): 2592-9, 2012 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-22292570

RESUMEN

Since seed coating with neonicotinoid insecticides was introduced in the late 1990s, European beekeepers have reported severe colony losses in the period of corn sowing (spring). As a consequence, seed-coating neonicotinoid insecticides that are used worldwide on corn crops have been blamed for honeybee decline. In view of the currently increasing crop production, and also of corn as a renewable energy source, the correct use of these insecticides within sustainable agriculture is a cause of concern. In this paper, a probable--but so far underestimated--route of environmental exposure of honeybees to and intoxication with neonicotinoid insecticides, namely, the atmospheric emission of particulate matter containing the insecticide by drilling machines, has been quantitatively studied. Using optimized analytical procedures, quantitative measurements of both the emitted particulate and the consequent direct contamination of single bees approaching the drilling machine during the foraging activity have been determined. Experimental results show that the environmental release of particles containing neonicotinoids can produce high exposure levels for bees, with lethal effects compatible with colony losses phenomena observed by beekeepers.


Asunto(s)
Anabasina/toxicidad , Abejas/efectos de los fármacos , Exposición a Riesgos Ambientales/análisis , Insecticidas/toxicidad , Material Particulado/química , Semillas/química , Zea mays/química , Agricultura , Anabasina/análisis , Animales , Guanidinas/análisis , Insecticidas/análisis , Microscopía Electrónica de Rastreo , Neonicotinoides , Tamaño de la Partícula , Tiazoles/análisis
2.
Anal Chem ; 83(16): 6355-62, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21718063

RESUMEN

Monodisperse Au(25)L(18)(0) (L = S(CH(2))(2)Ph) and [n-Oct(4)N(+)][Au(25)L(18)(-)] clusters were synthesized in tetrahydrofuran. An original strategy was then devised to oxidize them: in the presence of bis(pentafluorobenzoyl) peroxide, the neutral or the negatively charged clusters react as efficient electron donors in a dissociative electron-transfer (ET) process, in the former case yielding [Au(25)L(18)(+)][C(6)F(5)CO(2)(-)]. As opposed to other reported redox methods, this dissociative ET approach is irreversible, easily controllable, and clean, particularly for NMR purposes, as no hydrogen atoms are introduced. By using this approach, the -1, 0, and +1 charge states of Au(25)L(18) could be fully characterized by (1)H and (13)C NMR spectroscopy, using one- and two-dimensional techniques, in various solvents, and as a function of temperature. For all charge states, the NMR results and analysis nicely match recent structural findings about the presence of two different ligand populations in the capping monolayer, each resonance of the two ligand families displaying distinct NMR patterns. The radical nature of Au(25)L(18)(0) is particularly evident in the (1)H and (13)C NMR patterns of the inner ligands. The NMR behavior of radical Au(25)L(18)(0) was also simulated by DFT calculations, and the interplay between theory and experiments revealed a fundamental paramagnetic contribution coming from Fermi contact shifts. Interestingly, the NMR patterns of Au(25)L(18)(-) and Au(25)L(18)(+) were found to be quite similar, pointing to the latter cluster form as a diamagnetic species.


Asunto(s)
Oro/química , Espectroscopía de Resonancia Magnética/métodos , Compuestos Organometálicos/química , Azufre/química , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Electrones , Ligandos , Magnetismo , Modelos Moleculares , Conformación Molecular , Oxidación-Reducción , Electricidad Estática , Temperatura
3.
Invest New Drugs ; 29(6): 1213-23, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20567997

RESUMEN

Over the last few years a lot of research has been done to develop novel metal-based anti-cancer drugs, with the aim of improving clinical effectiveness, reducing general toxicity, and broadening the spectrum of activity. The search for novel metal-based antitumour drugs other than Pt agents includes the investigation of the cytotoxic activity of copper(I/II) compounds. Among these copper agents, particular attention has been recently devoted to hydrophilic copper(I) species bearing phosphines because of their noteworthy stability in aqueous media together with their remarkable in vitro cytotoxic activity. In this study we report on the synthesis, characterization and cytotoxic assays of a series of Cu(I) complexes with tris(2-cyanoethyl)phosphine (PCN) and bis(2-cyanoethyl)phenylphosphine (PCNPh). They were prepared by reaction of [Cu(CH(3)CN)(4)](+) or CuX(2) precursors with the pertinent phosphine in acetone or acetonitrile solutions producing compounds of the following formulation: [Cu(PCN)(2)](+) 2, [Cu(CH(3)CN)(PCN)](+) 3, [Cu(X)(PCN)] (X = Cl, 4; Br, 5), and [Cu(PCNPh)(2)](+) 6. The new copper(I) complexes were tested for their cytotoxic properties against a panel of several human tumour cell lines. Cellular copper uptake rate was correlated with cell growth inhibition in 2008 human ovarian cancer cells. Moreover, copper(I)-PCN complexes were evaluated for their ability to alter the most relevant mitochondrial pathophysiological parameters such as respiration, coupling, ATP-synthetase activity and membrane potential in isolated mitochondria. These data were correlated with changes in mitochondrial membrane potential and production of reactive oxygen species (ROS) in drug-treated 2008 cells.


Asunto(s)
Antineoplásicos/farmacología , Cobre/química , Neoplasias/tratamiento farmacológico , Fosfinas/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/patología , Neoplasias/patología , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Fosfinas/síntesis química , Fosfinas/química , Especies Reactivas de Oxígeno/metabolismo , Relación Estructura-Actividad
4.
Clin Lymphoma Myeloma Leuk ; 18(6): e267-e273, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29739722

RESUMEN

INTRODUCTION: The present study investigated the utility of fluorine-18 (18F) fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in assessing bone marrow involvement (BMI) compared with bone marrow biopsy (BMB) in newly diagnosed pediatric Hodgkin lymphoma (HL). PATIENTS AND METHODS: A total of 224 pediatric patients with HL underwent 18F-FDG PET/CT at staging. BMB or follow-up imaging was used as the standard of reference for the evaluation of BMI. RESULTS: 18F-FDG PET/CT was negative for BMI in 193 cases. Of the 193 patients, the findings for 16 were originally reported as doubtful and later interpreted as negative for BMI, with negative findings on follow-up imaging and BMB. At BMB, 1 of the 16 patients (6.25%) had BMI. Of the 193 patients, 192 (99.48%) had negative BMB findings. Thus, the 18F-FDG PET/CT findings were truly negative for 192 patients and falsely negative for 1 patient for BMI. CONCLUSION: 18F-FDG PET/CT showed high diagnostic performance in the evaluation of BMI in pediatric HL. Thus, BMB should be ideally reserved for patients presenting with doubtful 18F-FDG PET/CT findings for BMI.


Asunto(s)
Médula Ósea/diagnóstico por imagen , Enfermedad de Hodgkin/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Adolescente , Biopsia/métodos , Médula Ósea/patología , Niño , Preescolar , Femenino , Fluorodesoxiglucosa F18/administración & dosificación , Enfermedad de Hodgkin/patología , Humanos , Ilion , Masculino , Estadificación de Neoplasias , Radiofármacos/administración & dosificación , Estudios Retrospectivos
5.
J Med Chem ; 56(18): 7416-30, 2013 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-23964823

RESUMEN

Novel tetrahedral copper(I) mixed-ligand complexes of the type [Cu(X)(N(∩)N)(PCN)], 3-10, where X = Cl or Br, N(∩)N = 2,2'-bipyridine (bipy), 1,10-phenanthroline (phen), 5,6-dimethyl-1,10-phenanthroline (dmp), and dipyrido-[3,2-d:2',3'-f]-quinoxaline (dpq), and PCN = tris-(2-cyanoethyl)phosphine, have been synthetized and characterized by NMR, ESI-MS, and X-ray diffraction on two representative examples, [CuCl(phen)(PCN)]·DMF (5·DMF) and [CuBr(dpq)(PCN)]·2DMF (10·2DMF). Cu(I) complexes were evaluated for their in vitro antitumor properties against a panel of human cancer cell lines, including cisplatin- and multidrug-resistant sublines. The most effective complex, [CuCl(dpq)(PCN)] (9), exhibited nanomolar cytotoxicity toward both sensitive and resistant cancer cells, but it significantly inhibited the growth of cultured normal cells. In vitro DNA assays and single cell gel electrophoresis revealed that 9 induced DNA fragmentation resulting in cell apoptosis. In parallel, fluorescence in situ hybridization (FISH) micronucleus assay attested high levels of genotoxicity following treatment of peripheral blood lymphocytes with complex 9, suggesting that the potential risk posed by diimine metal complexes should be carefully reconsidered.


Asunto(s)
Cobre/química , Iminas/química , Compuestos Organometálicos/efectos adversos , Compuestos Organometálicos/farmacología , Aneugénicos/efectos adversos , Aneugénicos/química , Aneugénicos/metabolismo , Aneugénicos/farmacología , Antineoplásicos/efectos adversos , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Transporte Biológico , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , ADN/genética , ADN/metabolismo , Fragmentación del ADN/efectos de los fármacos , Humanos , Ligandos , Pruebas de Micronúcleos , Modelos Moleculares , Conformación Molecular , Compuestos Organometálicos/química , Compuestos Organometálicos/metabolismo , Relación Estructura-Actividad
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