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1.
Aten. prim. (Barc., Ed. impr.) ; 53(1): 43-50, ene. 2021. tab, graf
Artigo em Inglês | IBECS | ID: ibc-200088

RESUMO

OBJECTIVE: To estimate the effectiveness of a Medication Discrepancy Detection Service (MDDS), a collaborative service between the community pharmacy and Primary Care. DESIGN: Non-controlled before-and-after study. SETTING: Bidasoa Integrated Healthcare Organisation, Gipuzkoa, Spain. PARTICIPANTS: The service was provided by a multidisciplinary group of community pharmacists (CPs), general practitioners (GPs), and primary care pharmacists, to patients with discrepancies between their active medical charts and medicines that they were actually taking. Outcomes: The primary outcomes were the number of medicines, the type of discrepancy, and GPs' decisions. Secondary outcomes were time spent by CPs, emergency department (ED) visits, hospital admissions, and costs. RESULTS: The MDDS was provided to 143 patients, and GPs resolved discrepancies for 126 patients. CPs identified 259 discrepancies, among which the main one was patients not taking medicines listed on their active medical charts (66.7%, n = 152). The main GPs' decision was to withdraw the treatment (54.8%, n = 125), which meant that the number of medicines per patient was reduced by 0.92 (9.12 ± 3.82 vs. 8.20 ± 3.81; p < .0001). The number of ED visits and hospital admissions per patient were reduced by 0.10 (0.61 ± .13 vs 0.52 ± 0.91; p = .405 and 0.17 (0.33 ± 0.66 vs. 0.16 ± 0.42; p = .007), respectively. The cost per patient was reduced by (Euro)444.9 ((Euro)1003.3 ± 2165.3 vs. (Euro)558.4 ± 1273.0; p = .018). CONCLUSION: The MDDS resulted in a reduction in the number of medicines per patients and number of hospital admissions, and the service was associated with affordable, cost-effective ratios


OBJETIVOS: Estimar la efectividad del servicio de detección de discrepancias de la medicación, un servicio de colaboración entre la farmacia comunitaria y la atención primaria. DISEÑO: Estudio de intervención antes-después, sin grupo control. Emplazamiento: Organización Sanitaria Integrada de Bidasoa, Gipuzkoa, España. PARTICIPANTES: El servicio fue ofrecido por un grupo multidisciplinar que incluía farmacéuticos comunitarios (FC), médicos de atención primaria (MAP) y farmacéuticos de atención primaria a pacientes que presentaban discrepancias entre la medicación prescrita en la hoja de tratamiento activo y lo que realmente estaban tomando. Mediciones principales: Las variables principales del estudio fueron el número de medicamentos, tipo de discrepancia y la decisión del MAP. Las variables secundarias fueron tiempo invertido por el farmacéutico, visitas al servicio de urgencias, ingresos hospitalarios y los costes. RESULTADOS: El servicio se ofreció a 143 pacientes, y el MAP resolvió las discrepancias de un total de 126 pacientes. El FC identificó 259 discrepancias de las cuales la mayoría fue que el paciente no estaba tomando un medicamento prescrito (66,7%, n = 152). En la mayoría de los casos, la decisión del MAP fue suspender el tratamiento (54,8%, n = 125); el número de medicamentos que tomaba el paciente se redujo en un 0,92 (9,12 ± 3,82 vs. 8,20 ± 3,81; p < 0,0001). El número de visitas al hospital y los ingresos hospitalarios se redujeron en 0,10 (0,61 ± 0,13 vs. 0,52 ± 0,91; p = 0,405) y 0,17 puntos (0,33 ± 0,66 vs. 0,16 ± 0,42; p = 0,007), respectivamente. El coste por paciente se redujo en 444,9 (Euro) (1.003,3 ± 2.165,3 vs. 558,4 (Euro) ± 1.273,0; p = 0,018). CONCLUSIÓN: El servicio redujo el número de medicamentos que tomaba el paciente e ingresos hospitalarios y esto se relacionó con unos ratios de coste-efectividad positivos


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Erros de Medicação/estatística & dados numéricos , Serviços Comunitários de Farmácia/estatística & dados numéricos , Atenção Primária à Saúde/estatística & dados numéricos , Ensaios Clínicos Controlados não Aleatórios como Assunto , Clínicos Gerais/estatística & dados numéricos , Farmacêuticos/estatística & dados numéricos , Erros de Medicação/economia , Serviços Comunitários de Farmácia/economia , Atenção Primária à Saúde/economia , Hospitalização/estatística & dados numéricos , Hospitalização/economia
2.
Aten Primaria ; 53(1): 43-50, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32994060

RESUMO

OBJECTIVE: To estimate the effectiveness of a Medication Discrepancy Detection Service (MDDS), a collaborative service between the community pharmacy and Primary Care. DESIGN: Non-controlled before-and-after study. SETTING: Bidasoa Integrated Healthcare Organisation, Gipuzkoa, Spain. PARTICIPANTS: The service was provided by a multidisciplinary group of community pharmacists (CPs), general practitioners (GPs), and primary care pharmacists, to patients with discrepancies between their active medical charts and medicines that they were actually taking. OUTCOMES: The primary outcomes were the number of medicines, the type of discrepancy, and GPs' decisions. Secondary outcomes were time spent by CPs, emergency department (ED) visits, hospital admissions, and costs. RESULTS: The MDDS was provided to 143 patients, and GPs resolved discrepancies for 126 patients. CPs identified 259 discrepancies, among which the main one was patients not taking medicines listed on their active medical charts (66.7%, n=152). The main GPs' decision was to withdraw the treatment (54.8%, n=125), which meant that the number of medicines per patient was reduced by 0.92 (9.12±3.82 vs. 8.20±3.81; p<.0001). The number of ED visits and hospital admissions per patient were reduced by 0.10 (0.61±.13 vs 0.52±0.91; p=.405 and 0.17 (0.33±0.66 vs. 0.16±0.42; p=.007), respectively. The cost per patient was reduced by €444.9 (€1003.3±2165.3 vs. €558.4±1273.0; p=.018). CONCLUSION: The MDDS resulted in a reduction in the number of medicines per patients and number of hospital admissions, and the service was associated with affordable, cost-effective ratios.


Assuntos
Clínicos Gerais , Farmácias , Análise Custo-Benefício , Serviço Hospitalar de Emergência , Humanos , Farmacêuticos
3.
Int J Pharm Pract ; 27(1): 25-33, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29693292

RESUMO

INTRODUCTION: The Global Network of Age-friendly Cities is a project promoted by the World Health Organization as a response to demographic ageing and urbanization process. San Sebastian, Spain, is one of these Age-friendly Cities and community pharmacies of the city joined the initiative. OBJECTIVE: To define and implement the Age-friendly Pharmacy concept to promote active ageing, optimize the contribution of community pharmacies of San Sebastian to the friendliness of the city and to the improvement of quality of life of the ageing population. METHOD: A bottom-up participative approach was undertaken. A focus group was conducted to determine elderly people's opinions and expectations of community pharmacy. The information obtained was analysed using content analysis and validated for reliability, usefulness and applicability through three expert groups of community pharmacy owners and staff. KEY FINDINGS: Fifteen requirements were agreed, covering four main areas: relationships, pharmacy layout, pharmaceutical services and communication of services. Initially, 18 community pharmacies committed to become Age-friendly Pharmacies by pledging to these requirements and the Official Pharmacist Association of Gipuzkoa supported pharmacies in the implementation of the initiative. CONCLUSION: This study suggests that there is demand for a patient-centred community pharmacy to support older people, in which pharmaceutical care services are required. The 18 Age-friendly Pharmacies together with the Official Pharmacist Association of Gipuzkoa have publicly committed to actively work on social and patient-centred care to meet the needs of the ageing population.


Assuntos
Serviços Comunitários de Farmácia/organização & administração , Envelhecimento Saudável , Farmácias/organização & administração , Pesquisa Qualitativa , Qualidade de Vida , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Grupos Focais , Necessidades e Demandas de Serviços de Saúde/organização & administração , Humanos , Masculino , Pessoa de Meia-Idade , Assistência Centrada no Paciente/métodos , Assistência Centrada no Paciente/organização & administração , Reprodutibilidade dos Testes , Espanha
4.
Bioorg Med Chem Lett ; 26(3): 903-906, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26750255

RESUMO

We report the synthesis and in vitro activity against Trypanosoma cruzi epimastigotes of 15 novel quinoxaline derivatives. Ten of the derivatives presented IC50 values lower than the reference drugs Nfx and Bzn; four of them standed out with IC50 values lower than 1.5 µM. Moreover, unspecific cytotoxicity and genotoxicity studies are also reported. Compound 14 showed a SI higher than 24, whereas compound 10 was the only one that was negative in the genotoxicity screening.


Assuntos
Quinoxalinas/química , Tripanossomicidas/síntese química , Animais , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Nitrogênio/química , Óxidos/química , Quinoxalinas/síntese química , Quinoxalinas/farmacologia , Relação Estrutura-Atividade , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Células Vero
5.
Int J Food Sci Nutr ; 66 Suppl 1: S13-21, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26241007

RESUMO

The growing presence of products on the market with added value in terms of health makes essential their regulation and harmonization in critical aspects such as safety. The toxicology applied to the bioactive compounds should demonstrate the absence of toxic effects at doses advised for consumption, as well as evaluate the potential toxic effects in the assumption that the products are used in quantities superior to those recommended. The specific strategy should be defined case by case; therefore, prior to any toxicological development, it is essential to study all the information regarding the bioactive compounds (BACs) characterization, nutridynamics and nutrikinetics, that is available. In this guideline, a general strategy to be applied in the development of BACs is proposed. It includes a first in vitro phase to discard genotoxicity and endocrine effects and a second in vivo phase with different possibilities regarding the duration and the extension of the studies.


Assuntos
Análise de Alimentos/métodos , Rotulagem de Alimentos/normas , Inocuidade dos Alimentos/métodos , Alimento Funcional/normas , Valor Nutritivo , Disponibilidade Biológica , Rotulagem de Alimentos/legislação & jurisprudência , Alimento Funcional/efeitos adversos , Legislação sobre Alimentos
6.
Food Chem Toxicol ; 76: 116-24, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25530104

RESUMO

Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) are genotoxic mycotoxins that can contaminate a variety of foodstuffs, the liver and the kidney being their target organs, respectively. The micronucleus (MN) assay (bone marrow) and the comet assay (liver and kidney) were performed simultaneously in F344 rats, treated with AFB1 (0.25 mg/kg b.w.), OTA (0.5 mg/kg b.w.) or both mycotoxins. After AFB1 treatment, histopathology and biochemistry analysis showed liver necrosis, focal inflammation and an increase in Alanine Aminotransferase and Aspartate Aminotransferase. OTA alone did not cause any alteration. The acute hepatotoxic effects caused by AFB1 were less pronounced in animals treated with both mycotoxins. With regard to the MN assay, after 24 h, positive results were obtained for AFB1 and negative results were obtained for OTA, although both toxins caused bone marrow toxicity. In the combined treatment, OTA reduced the toxicity and the number of MN produced by AFB1. In the comet assay, after 3 h, positive results were obtained for AFB1 in the liver and for OTA in the kidney. The combined treatment reduced DNA damage in the liver and had no influence in the kidney. Altogether, these results may be indicative of an antagonistic relationship regarding the genotoxicity of both mycotoxins.


Assuntos
Aflatoxina B1/toxicidade , Dano ao DNA/efeitos dos fármacos , Ocratoxinas/toxicidade , Aflatoxina B1/sangue , Animais , Ensaio Cometa , Relação Dose-Resposta a Droga , Hepatócitos/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Testes para Micronúcleos , Ocratoxinas/sangue , Ratos , Ratos Endogâmicos F344
7.
Food Chem Toxicol ; 60: 397-403, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23948352

RESUMO

Spent coffee has been shown as a good source of hydrophilic antioxidant compounds. The ability of two spent coffee extracts rich in caffeoylquinic acids, mainly dicaffeoylquinic acids, and caffeine (Arabica filter and Robusta espresso) to protect against oxidation and DNA damage in human cells (HeLa) was evaluated at short (2 h) and long (24 h) exposure times. Cell viability (MTT) was not affected by spent coffee extracts (>80%) up to 1000 µg/mL after 2 h. Both spent coffee extracts significantly reduced the increase of ROS level and DNA strand breaks (29-73% protection by comet assay) induced by H2O2. Pretreatment of cells with robusta spent coffee extract also decreased Ro photosensitizer-induced oxidative DNA damage after 24 h exposure. The higher effectiveness of Robusta spent coffee extract, with less caffeoylquinic acids and melanoidins, might be due to other antioxidant compounds, such as caffeine and other Maillard reaction products. This work evidences the potential antioxidant and genoprotective properties of spent coffee in human cells.


Assuntos
Antimutagênicos/farmacologia , Antioxidantes/farmacologia , Café/química , Dano ao DNA/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cafeína/análise , Cafeína/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Células HeLa , Humanos , Peróxido de Hidrogênio/efeitos adversos , Reação de Maillard , Estresse Oxidativo/efeitos dos fármacos , Ácido Quínico/análogos & derivados , Ácido Quínico/análise , Ácido Quínico/farmacologia , Espécies Reativas de Oxigênio
8.
Eur J Med Chem ; 66: 324-34, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23811257

RESUMO

As a continuation of our research and with the aim of obtaining new agents against Chagas disease, an extremely neglected disease which threatens 100 million people, eighteen new quinoxaline 1,4-di-N-oxide derivatives have been synthesized following the Beirut reaction. The synthesis of the new derivatives was optimized through the use of a new and more efficient microwave-assisted organic synthetic method. The new derivatives showed excellent in vitro biological activity against Trypanosoma cruzi. Compound 17, which was substituted with fluoro groups at the 6- and 7-positions of the quinoxaline ring, was the most active and selective in the cytotoxicity assay. The electrochemical study showed that the most active compounds, which were substituted by electron-withdrawing groups, possessed a greater ease of reduction of the N-oxide groups.


Assuntos
Antiprotozoários/química , Antiprotozoários/farmacologia , Doença de Chagas/tratamento farmacológico , Óxidos/química , Quinoxalinas/química , Quinoxalinas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antiprotozoários/uso terapêutico , Antiprotozoários/toxicidade , Linhagem Celular , Eletroquímica , Camundongos , Mutagênese/efeitos dos fármacos , Quinoxalinas/uso terapêutico , Quinoxalinas/toxicidade
9.
Mutagenesis ; 28(3): 271-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23448901

RESUMO

The alkaline comet assay, when employed as a genotoxicity test, has relatively low sensitivity because it fails to detect--at non-cytotoxic concentrations--known genotoxins that do not induce breaks or alkali-labile sites. We demonstrate that this limitation is overcome by incorporating in the assay the DNA repair enzyme formamidopyrimidine DNA glycosylase (FPG) to convert damaged bases to breaks. We tested 11 chemicals in human TK-6 cells: three non-cytotoxic--D-mannitol, Tris and EDTA; two cytotoxic--Triton X-100 and fluometuron; and six genotoxic--methylmethanesulphonate (MMS), methylnitrosourea (MNU), cyclophosphamide, benzo(a)pyrene, 4-nitroquinoline-1-oxide (4NQO) and etoposide. At concentrations of MMS, MNU, benzo(a)pyrene or 4NQO causing little or no cytotoxicity and few if any DNA breaks, FPG substantially enhanced the cellular response. Etoposide increased breaks but not FPG-sensitive sites. Cyclophosphamide, a DNA cross linker, gave a response without FPG at 1 µM, but there was no increase with FPG. Triton X-100-induced breaks were secondary to cytotoxicity. The remaining compounds induced no damage. Thus, FPG enhances sensitivity of the comet assay without compromising selectivity.


Assuntos
Ensaio Cometa , DNA-Formamidopirimidina Glicosilase/metabolismo , Sensibilidade e Especificidade , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Mutagênicos/toxicidade
10.
Bioanalysis ; 5(3): 289-305, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23394696

RESUMO

BACKGROUND: IFN-α5 has been demonstrated to induce stronger signaling and higher expression of antiviral genes than IFN-α2, which is the current treatment in chronic viral hepatitis. However, there is no specific and validated quantification method in order to conduct kinetic studies as part of the preclinical and clinical evaluation for regulatory purposes. RESULTS: A novel integration of an antiviral assay against the cytopathic effect of the encephalomyocarditis virus in HeLa cells with a very sensitive method for assay processing - the Vialight(®) Plus assay - is presented for IFN-α5 activity quantification. The bioassay has been validated in macaque and human serum and it has been demonstrated to be selective, precise and accurate. CONCLUSION: The validated bioassay meets suitable acceptance criteria for these types of biological assays.


Assuntos
Interferon-alfa/sangue , Animais , Bioensaio/métodos , Bioensaio/normas , Infecções por Cardiovirus/sangue , Efeito Citopatogênico Viral , Vírus da Encefalomiocardite/fisiologia , Células HeLa , Humanos , Macaca
11.
Food Chem Toxicol ; 49(9): 1935-42, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21571028

RESUMO

The impact of age and gender on Ochratoxin A (OTA) distribution in kidney and liver were studied. OTA was quantified in kidney and liver of young and mature rats of both sexes. Data was fit simultaneously using the population approach with NONMEM program. Fed and fasted mature males showed a 30% decrease and an 11% increase in relative bioavailability, respectively, in comparison with the rest of the groups. The OTA concentrations reached in kidney and liver were very similar between both organs. The models that best fit to data were the ones that considered that distribution of OTA to kidney and liver occurs from the central compartment and that elimination occurs mainly from the liver compartment. The kinetic analysis revealed that both, the apparent volume of distribution of the central compartment (V/F) and the apparent volume of distribution of the liver and kidney compartments (V(L,K)/F) increased significantly with body weight. Thus, the sex differences observed in organs distribution are a reflection of the differences in relative bioavailability observed in adult males, as a consequence of the fed and fasted conditions and to the significant higher body weight of mature males which directly affected the V/F and V(L,K)/F.


Assuntos
Rim/metabolismo , Fígado/metabolismo , Ocratoxinas/farmacocinética , Animais , Feminino , Masculino , Ratos , Ratos Endogâmicos F344 , Distribuição Tecidual
12.
Bioorg Med Chem ; 18(9): 3125-32, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20371184

RESUMO

The heterocyclic N-oxide, 3-amino-1,2,4-benzotriazine 1,4-dioxide (tirapazamine, 1), shows promising antitumor activity in preclinical studies, but there is a continuing need to explore new compounds in this general structural category. In the work described here, we examined the properties of 7-chloro-2-thienylcarbonyl-3-trifluoromethylquinoxaline 1,4-dioxide (9h). We find that 9h causes redox-activated, hypoxia-selective DNA cleavage that mirrors the lead compound, tirapazamine, in both mechanism and potency. Furthermore, we find that 9h displays hypoxia-selective cytotoxicity against human cancer cell lines.


Assuntos
DNA/química , DNA/efeitos dos fármacos , Hipóxia , Quinoxalinas/química , Quinoxalinas/farmacologia , Antineoplásicos/farmacologia , Cromatografia Líquida de Alta Pressão , Sistema Enzimático do Citocromo P-450/química , DNA/metabolismo , Clivagem do DNA , Humanos , Estrutura Molecular , NADP/química , Oxirredução , Tirapazamina , Triazinas/farmacologia
13.
J Chromatogr A ; 1215(1-2): 100-6, 2008 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-19027908

RESUMO

A fast and simple HPLC-FLD (high-performance liquid chromatography-fluorescence detection) analytical method has been developed and validated for the determination of ochratoxin A in rat plasma, kidney and liver. The extraction method, calibration curves and chromatographic conditions are common for the three matrices. Plasma and homogenized tissue samples (250 microL) were extracted with ethanol (400 microL) and trichloroacetic acid 20% (w/v) (50 microL). Supernatants were directly injected into the HPLC system, analyzed on a 5-microm (25 cm x 0.4 cm) Tracer Extrasil ODS2 column using FLD (excitation wavelength=225 nm, emission wavelength=461 nm). The mobile phase was 29:29:42 (v/v) methanol-acetonitrile-sodium acetate. The small volume of sample needed which allows the obtaining of ochratoxin A levels in individual tissue samples from small animals and the wide range of concentrations that could be analyzed make this method easy to apply in toxicology and toxicokinetic studies of this mycotoxin, even in low dose carcinogenic studies. This method was linear and selective for all the matrices. Precision and accuracy were always <10% and recovery was very efficient in each case. Limits of detection and quantification were also calculated in plasma (1 and 8.4 microg/L), kidney (14.3 and 55.8 microg/kg) and liver (4.1 and 52.8 microg/kg). Stability of the tissue homogenates was assured for at least 10 months at -80 degrees C. The method has been successfully applied to the analysis of rat samples after 7 days of ochratoxin A (0.5mg/kg b.w. dissolved in an aqueous NaHCO(3) solution) administration by oral gavage.


Assuntos
Análise Química do Sangue , Cromatografia Líquida de Alta Pressão/métodos , Rim/química , Fígado/química , Testes de Toxicidade , Animais , Masculino , Ratos , Ratos Endogâmicos F344 , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência
14.
Toxicol Appl Pharmacol ; 230(2): 197-207, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18417182

RESUMO

Ochratoxin A (OTA), a naturally occurring mycotoxin, is nephrotoxic in all animal species tested and is considered a potent renal carcinogen, particularly in male rats. Its mechanism of toxicity is still unknown, although oxidative stress appears to be a plausible mechanism. Therefore, the objective of this study was to identify the biological pathways that are modulated in vivo by OTA in male F344 rats in order to gain further insight into its mechanism of renal toxicity. Rats were gavaged daily with OTA (500 microg/kg bw) and gene expression profiles in target and non-target organs were analyzed after 7 and 21 days administration. As was expected, a time-dependent increase of OTA concentrations was found in plasma, kidney and liver, with the concentrations found in both tissues being quite similar. However, histopathological examinations only revealed changes in kidney; signs of nephrotoxicity involving single cell necrosis and karyomegalic nuclei were observed in the treated rats. The number of differentially expressed genes in kidney was much higher than in liver (541 versus 11 at both time points). Several similarities were observed with other in vivo gene expression data. However, great differences were found with previous in vitro gene expression data, with the exception of DNA damage response which was not observed at mRNA level in any of our study conditions. Down-regulation was the predominant effect. Oxidative stress response pathway and genes involved in metabolism and transport were inhibited at both time points. RGN (regucalcin) - a gene implicated in calcium homeostasis - was strongly inhibited at both time points and genes implicated in cell survival and proliferation were up-regulated at day 21. Moreover, translation factors and annexin genes were up-regulated at both time points. Apart from oxidative stress, alterations of the calcium homeostasis and cytoskeleton structure may be present at the first events of OTA toxicity.


Assuntos
Rim/metabolismo , Fígado/metabolismo , Ocratoxinas/farmacologia , Administração Oral , Animais , Anexinas/metabolismo , Peso Corporal/efeitos dos fármacos , Cálcio/metabolismo , Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Necrose , Ocratoxinas/farmacocinética , Ocratoxinas/toxicidade , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Ratos , Ratos Endogâmicos F344 , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Chem Biol Interact ; 168(2): 95-105, 2007 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-17420013

RESUMO

Some anticancer compounds are pro-drugs which give rise to toxic species through enzymatic reduction. The quinoxaline-di-N-oxide derivative Q-85 HCl (7-chloro-3-[[(N,N-dimethylamino)propyl]amino]-2-quinoxalinecarbonitrile 1,4-di-N-oxide hydrochloride) is a bioreductive compound selectively toxic in hypoxia. Due to the possibility of secondary tumors the study of the genotoxic capability of antitumoral drugs is very important. The aim of this study was to assess the ability of Q-85 HCl to produce reactive oxygen species (ROS) and oxidative DNA damage in Caco-2 cells, both in hypoxia and in well-oxygenated conditions. Secondly, we attempted to evaluate the effect of vitamins C and E under hypoxic and normoxic conditions, in order to determine if these antioxidant substances modify Q-85 HCl effect in hypoxic cells or possibly exert a protective action in normal cells. Caco-2 cells were treated with Q-85 HCl for 2h, at high concentrations in normoxia (0.1-5 microM) and at low concentrations in hypoxia (0.002-0.1 microM). In normoxia, a dose-related significant increase in intracellular ROS level was evident; in hypoxia all the concentrations produced very high level of ROS. Just after the treatment and 24h later, oxidative DNA damage was evaluated by the modified comet assay after post-digestion of the cells with formamidopyrimidine-DNA glycosylase (FPG) and endonuclease III (Endo III). Q-85 HCl treatment evoked a significant dose-dependent increase in the total comet score of the cells both in hypoxia and normoxia, indicating that this compound or some metabolite is able to oxidize purine and pyrimidine bases. After 24h DNA damage caused by the compound was completely repaired with only one exception: cells treated with the highest concentration of Q-85 HCl in hypoxia and post-digested with FPG. Vitamin C (5-100 microM) and vitamin E (500-400 microM) did not have a pro-oxidant effect in Caco-2 cells. Treatment of cells with vitamin C (10 microM) or vitamin E (100 microM) did not significantly reduce oxidative DNA damage in hypoxia and normoxia. In conclusion, the use of these vitamins would not hinder toxicity against hypoxic cells, but a protective effect in normoxic cells was not evident.


Assuntos
Ácido Ascórbico/farmacologia , Dano ao DNA , Pró-Fármacos/farmacologia , Quinoxalinas/farmacologia , Vitamina E/farmacologia , Células CACO-2 , DNA Glicosilases/metabolismo , DNA-Formamidopirimidina Glicosilase/metabolismo , Humanos , Hipóxia/metabolismo , Espécies Reativas de Oxigênio/metabolismo
16.
Toxicol Appl Pharmacol ; 220(2): 216-24, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17316727

RESUMO

Ochratoxin A (OTA) is a mycotoxin often found in cereals and agricultural products. There is unequivocal evidence of renal carcinogenicity of OTA in male rats, although the mechanism of action is unknown. At present, available data support an epigenetic mechanism (DNA non-reactive) resulting from oxidative stress and cytotoxicity, because a direct OTA interaction with DNA has not been demonstrated. Genotoxic mechanism (DNA-reactive vs. DNA non-reactive) may have implications on human risk assessment. Therefore, the aim of the present work was to identify biological pathways modulated by OTA in vitro in a human renal cell line (HK-2) to contribute to the elucidation of the mechanism of OTA toxicity. For that purpose, cells were exposed to 50 microM OTA during 6 and 24 h, and gene expression profiles were analyzed using Affymetrix Human Genome U133 A 2.0 Gene Chips. Under the same experimental conditions, genotoxicity was evaluated by the modified comet assay using FPG and Endo III to detect oxidative DNA damage, and intracellular ROS level by the H(2)DCF assay. After 6 h, with slight cytotoxicity (83% survival), genes involved in mitochondrial electron transport chain were up-regulated; and after 24 h, with a more pronounced cytotoxicity (51% survival), genes implicated in oxidative stress response were also up-regulated. Increase in intracellular ROS level and oxidative DNA damage was evident at both exposure times being more pronounced with high cytotoxicity. On the contrary, up-regulation of genes implicated in DNA damage response, as cell cycle control or apoptosis, was not detected at any exposure time. In conclusion, these results support a DNA non-reactive mechanism of OTA genotoxicity.


Assuntos
DNA/genética , Expressão Gênica/efeitos dos fármacos , Mutagênicos , Ocratoxinas/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular , Ensaio Cometa , DNA/efeitos dos fármacos , Dano ao DNA , Transporte de Elétrons/efeitos dos fármacos , Corantes Fluorescentes , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , L-Lactato Desidrogenase/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , RNA/biossíntese , RNA/genética , Espécies Reativas de Oxigênio/metabolismo , Sais de Tetrazólio , Tiazóis
17.
Mutagenesis ; 22(1): 35-42, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17130176

RESUMO

Ochratoxin A (OTA) is a mycotoxin produced by species of the genera Aspergillus and Penicillium. The kidneys are the target organ of this mycotoxin and it is considered a potent renal carcinogen in male rats. The mechanisms of its genotoxicity and carcinogenicity have been studied thoroughly, but controversial results have been published. The aim of this study was to evaluate the ability of OTA to produce single-strand DNA breaks and oxidative DNA damage in the human renal proximal tubular epithelial cell line (HK-2), due to the fact that there is no study on human kidney cells as the toxic target. In addition, we attempted to determine if biotransformation processes mediate OTA genotoxicity. Therefore, single-cell gel electrophoresis assay (comet assay) was performed after 3h- and 6h-treatments using different OTA concentrations, both cytotoxic and non-cytotoxic, in order to be able to distinguish a genotoxic effect of the mycotoxin from an indirect effect derived from its general cellular toxicity. No effect was shown where no cytotoxicity was found, both in the presence and in the absence of metabolic activation (10% rat liver S9-mix). However, oxidative DNA damage was shown at cytotoxic concentrations when formamidopyrimidine DNA glycosylase (FPG) and endonucleaseIII (EndoIII) were introduced in the assay with or without metabolic activation. Furthermore, at these concentrations, an elevation of reactive oxygen species was measured and pre-incubation with N-acetyl-L-cysteine was able to produce a slight protective effect on OTA-induced oxidative DNA damage as well as cytotoxicity. These data suggest that OTA is not acting as a direct genotoxic carcinogen and that oxidative stress is implicated in the genotoxicity and cytotoxicity observed in these human renal cells.


Assuntos
Dano ao DNA/efeitos dos fármacos , Ocratoxinas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Acetilcisteína/farmacologia , Animais , Antígenos CD/metabolismo , Antioxidantes/farmacologia , Caderinas/metabolismo , Carcinógenos/toxicidade , Linhagem Celular Transformada , Sistema Enzimático do Citocromo P-450/metabolismo , Citotoxinas/farmacologia , Humanos , Rim/citologia , Rim/metabolismo , Modelos Biológicos , Ratos , Espécies Reativas de Oxigênio/metabolismo
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