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Id: biblio-1022030
Autor: Fan, Shuanghu; Li, Kang; Yan, Yanchun; Wang, Junhuan; Wang, Jiayi; Qiao, Cheng; Yang, Ting; Jia, Yang; Zhao, Baisuo.
Título: A novel chlorpyrifos hydrolase CPD from Paracoccus sp. TRP: molecular cloning, characterization and catalytic mechanism
Fonte: Electron. j. biotechnol;31:10-16, Jan. 2018. graf, tab, ilust.
Idioma: en.
Projeto: National Natural Science Foundation of China; . Basic Research Fund of CAAS.
Resumo: Background: Biodegradation is a reliable approach for efficiently eliminating persistent pollutants such as chlorpyrifos. Despite many bacteria or fungi isolated from contaminated environment and capable of degrading chlorpyrifos, limited enzymes responsible for its degradation have been identified, let alone the catalytic mechanism of the enzymes. Results: In present study, the gene cpd encoding a chlorpyrifos hydrolase was cloned by analysis of genomic sequence of Paracoccus sp. TRP. Phylogenetic analysis and BLAST indicated that CPD was a novel member of organophosphate hydrolases. The purified CPD enzyme, with conserved catalytic triad (Ser155-Asp251-His281) and motif Gly-Asp-Ser-Ala-Gly, was significantly inhibited by PMSF, a serine modifier. Molecular docking between CPD and chlorpyrifos showed that Ser155 was adjacent to chlorpyrifos, which indicated that Ser155 may be the active amino acid involved in chlorpyrifos degradation. This speculation was confirmed by site-directed mutagenesis of Ser155Ala accounting for the decreased activity of CPD towards chlorpyrifos. According to the key role of Ser155 in chlorpyrifos degradation and molecular docking conformation, the nucleophilic catalytic mechanism for chlorpyrifos degradation by CPD was proposed. Conclusion: The novel enzyme CPD was capable of hydrolyze chlorpyrifos and Ser155 played key role during degradation of chlorpyrifos.
Descritores: Paracoccus/enzimologia
Biodegradação Ambiental
Clonagem Molecular
Análise de Sequência
Esterases/isolamento & purificação
Responsável: CL1.1 - Biblioteca Central

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Texto completo SciELO Brasil
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Id: biblio-888952
Autor: Fu, LC; Lv, Y; Zhong, Y; He, Q; Liu, X; Du, LZ.
Título: Tyrosine phosphorylation of Kv1. 5 is upregulated in intrauterine growth retardation rats with exaggerated pulmonary hypertension
Fonte: Braz. j. med. biol. res = Rev. bras. pesqui. méd. biol;50(11):e6237, 2017. tab, graf.
Idioma: en.
Projeto: National Natural Science Foundation.
Resumo: Intrauterine growth retardation (IUGR) is associated with the development of adult-onset diseases, including pulmonary hypertension. However, the underlying mechanism of the early nutritional insult that results in pulmonary vascular dysfunction later in life is not fully understood. Here, we investigated the role of tyrosine phosphorylation of voltage-gated potassium channel 1.5 (Kv1.5) in this prenatal event that results in exaggerated adult vascular dysfunction. A rat model of chronic hypoxia (2 weeks of hypoxia at 12 weeks old) following IUGR was used to investigate the physiological and structural effect of intrauterine malnutrition on the pulmonary artery by evaluating pulmonary artery systolic pressure and vascular diameter in male rats. Kv1.5 expression and tyrosine phosphorylation in pulmonary artery smooth muscle cells (PASMCs) were determined. We found that IUGR increased mean pulmonary artery pressure and resulted in thicker pulmonary artery smooth muscle layer in 14-week-old rats after 2 weeks of hypoxia, while no difference was observed in normoxia groups. In the PASMCs of IUGR-hypoxia rats, Kv1.5 mRNA and protein expression decreased while that of tyrosine-phosphorylated Kv1.5 significantly increased. These results demonstrate that IUGR leads to exaggerated chronic hypoxia pulmonary arterial hypertension (CH-PAH) in association with decreased Kv1.5 expression in PASMCs. This phenomenon may be mediated by increased tyrosine phosphorylation of Kv1.5 in PASMCs and it provides new insight into the prevention and treatment of IUGR-related CH-PAH.
Descritores: Organofosfatos/metabolismo
Canal de Potássio Kv1.5/análise
Hipóxia Fetal/complicações
Hipóxia Fetal/fisiopatologia
Retardo do Crescimento Fetal/metabolismo
Hipertensão Pulmonar/etiologia
Músculo Liso Vascular/química
Efeitos Tardios da Exposição Pré-Natal/metabolismo
Artéria Pulmonar/fisiopatologia
Artéria Pulmonar/patologia
Fatores de Tempo
RNA Mensageiro/análise
Distribuição Aleatória
Regulação para Cima
Ratos Sprague-Dawley
Modelos Animais de Doenças
Retardo do Crescimento Fetal/etiologia
Reação em Cadeia da Polimerase em Tempo Real
Hipertensão Pulmonar/fisiopatologia
Hipertensão Pulmonar/patologia
Músculo Liso Vascular/patologia
Limites: Animais
Responsável: BR1.1 - BIREME

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Id: biblio-859618
Autor: Srivastav, Ajai Kumar; Srivastava, Sanjay Kumar; Tripathi, Sarojni; Mishra, Diwakar; Srivastav, Sunil Kumar.
Título: Morpho-toxicology of chlorpyrifos to prolactin cells of a freshwater catfish, Heteropneustes fossilis / Morfotoxicologia de clorpirifos para as células de prolactina de bagre de água doce Heteropneustes fossilis
Fonte: Acta sci., Biol. sci;34(4):443-449, Oct.-Dec. 2012. ilus.
Idioma: en.
Resumo: In the present study, an organophosphorus compound Coroban (active ingredient chlorpyrifos ­ E.C. 20%) was used. In short-term exposure the fish were subjected to 0.8 of 96h LC50 value of chlorpyrifos (1.76 mg L-1) for 96h. In long-term exposure the experiment was performed for 28 days by using 0.2 of 96h LC50 value of chlorpyrifos (0.44 mg L-1). Fish were killed on each time intervals from control and experimental (chlorpyrifos) groups after 24, 48, 72, and 96h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were collected and sera were analyzed for calcium. Pituitary glands were fixed for histological studies and stained with Herlant tetrachrome and Heidenhain's azan techniques. Short-term exposure of chlorpyrifos caused decrease in the serum calcium levels. No change was noticed in the prolactin cells of chlorpyrifos treated fish. Long-term treatment with chlorpyrifos provoked hypocalcemia. The prolactin cells of treated fish exhibited slight degranulation after 21 days whereas the nuclear volume remained unchanged. After 28 days, the prolactin cells exhibited further degranulation and the nuclear volume recorded an increase. Cytolysis and vacuolization were also visible.

No estudo presente, o composto organofosforo Coroban (ingrediente ativo clorpirifo ­ E.C. 20%) foi usado. Na exposição a curto prazo os peixes foram submetido a 0,8 de valor LC50 de 96h de clorpirifo (1,76 mg L-1) durante 96h. Na exposição a longo prazo o experimento foi executado durante 28 dias usando 0,2 de valor LC50 de 96h de clorpirifos (0,44 mg L-1). Os peixes foram mortos a cada intervalo dos grupos controle e experimental (clorpirifos) após 24, 48, 72, e 96h em exposição a curto prazo e após 7, 14, 21, e 28 dias no experimento a longo prazo. As amostras de sangue foram colhidas e o soro foi analisado para cálcio. As glândulas pituitárias foram fixadas para estudos histológicos e colorido por tetracromo de Herlant e por técnicas de azan do Heidenhain. A exposição a curto prazo do clorpirifo diminuiu os níveis de cálcio no soro. Nenhuma mudança foi observada nas células de prolactina nos peixes tratados com clorpirifo. O tratamento a longo prazo com clorpirifo causou hipocalcemia. As células de prolactina dos peixes tratados mostraram uma leve degranulação após 21 dias ao passo que o volume nuclear permaneceu inalterado. Depois de 28 dias, as células de prolactina mostraram mais degranulação e o volume nuclear registrou um aumento. Citólise e vacuolização também eram visíveis.
Descritores: Peixes-Gato
Água Doce
Responsável: BR513.1 - Biblioteca Central

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Id: lil-769246
Autor: Moraes, Alessandra C; Prado, Ed JR; Faria, Vanessa P; Gírio, Thais MS; Manrique, Wilson G; Belo, Marco AA.
Título: Clinical safety of dichlorvos (45%), cypermethrin (5%) and piperonyl butoxide (25%) administered by spray on the skin of cattle / Seguridad clínica del diclorvos (45%), cipermetrina (5%) y butóxido de piperonilo (25%) administrado por aspersión sobre la piel de bovinos
Fonte: Rev. MVZ Córdoba;20(supl.1):4874-4883, Dec. 2015. ilus, tab.
Idioma: en.
Resumo: Objective. Due to the importance of controlling ectoparasites, associated with the necessity of technical knowledge on the safety of topical treatment with organophosphates, pyrethroids and piperonyl butoxide to the animal organism, this bioassay was carried out to evaluate the clinical safety of the association of dichlorvos (45%) + cypermethrin (5%) + piperonyl butoxide (25%) administered by spray on the skin of cattle, through the study of clinical parameters, biochemical, haematological and behavioral changes. Materials and methods. Sixteen crossbred animals with a mean age of 18 months, males and females grouped into two treatments with eight animals each: T1 (1:800 v/v) and T2 (1:200 v/v). Were collected blood samples at six different times: before treatment (BT), 24, 48, 72, 96 and 192 hours post treatment (HPT). Results. The antiparasitic association administered by spray on the skin did not result in changes in the enzymatic activity of ALT, AST, GGT and ALP, as well as in serum albumin, triglycerides, cholesterol, urea and creatinine, demonstrating the safety of this antiparasitic compound for maintaining hepatic and renal functionality. The erythrocyte, leukocyte and platelet studies showed no changes caused by treatments, and no clinical signs and behavioral changes were observed after treatment. Conclusions. These findings demonstrated good safety margin for spray treatment on the skin with this antiparasitic compound, even when administered at a dilution of 1:200 v/v, which is four times the dose recommended for ectoparasite control.

Objetivo. Debido a la importancia del control de ectoparásitos en bovinos, asociado a la necesidad de conocimientos técnicos sobre la seguridad del tratamiento tópico con organofosforados, piretroides y butóxido de piperonilo, se realizó este bioensayo para la evaluación de la seguridad clínica de la asociación de diclorvos (45%) + cipermetrina (5%) + butóxido de piperonilo (25%), administrado por aspersión en la piel del ganado bovino, a través del estudio de los parámetros clínicos, bioquímicos, hematológicos y comportamentales. Materiales y métodos. Dieciséis animales entre machos y hembras cruzados con edad media de 18 meses, agrupados en dos tratamientos de ocho animales cada uno: T1 (1:800 v/v) y T2 (1:200 v/v). Fueron colectadas muestras de sangre en seis momentos diferentes: antes del tratamiento (BT), 24, 48, 72, 96 y 192 horas post tratamiento (HPT). Resultados. La asociación antiparasitaria administrada por aspersión en la piel no alteró la actividad enzimática de ALT, AST, GGT y FA, así como la albúmina, triglicéridos, colesterol, urea y creatinina, que demuestra la seguridad de este compuesto antiparasitario en la función renal y hepática. El análisis de eritrocitos, leucocitos y plaquetas no mostraron cambios en los tratamientos, tampoco fueron observados signos clínicos y de comportamiento post tratamiento. Conclusiones. Estos resultados demostraron buen margen de seguridad en el tratamiento por aspersión en la piel con este compuesto antiparasitario, incluso cuando se administra en una dilución de 1:200 v/v, que es cuatro veces la dosis recomendada para el control de ectoparásitos.
Descritores: Bovinos
Butóxido de Piperonila
Rego por Aspersão
Responsável: CO332 - Facultad de Medicina

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Texto completo SciELO Brasil
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Id: lil-728904
Autor: Pereira, Boscolli Barbosa; Limongi, Jean Ezequiel; Campos Júnior, Edimar Olegário de; Luiz, Denis Prudencio; Kerr, Warwick Estevam.
Título: Effects of piperonyl butoxide on the toxicity of the organophosphate temephos and the role of esterases in the insecticide resistance of Aedes aegypti
Fonte: Rev. Soc. Bras. Med. Trop;47(5):579-582, Sep-Oct/2014. tab.
Idioma: en.
Resumo: Introduction The effects of piperonyl butoxide (PBO) on the toxicity of the organophosphate temephos (TE) and the role of esterases in the resistance of Aedes aegypti to this insecticide were evaluated. Methods A. aegypti L4 larvae susceptible and resistant to TE were pre-treated with PBO solutions in acetone at concentrations of 0.125, 0.25, 0.5, 1, and 2% for 24h and subsequently exposed to a diagnostic concentration of 0.02mg/L aqueous TE solution. The esterase activity of the larvae extracts pre-treated with varying PBO concentrations and exposed to TE for three time periods was determined. Results At concentrations of 0.25, 0.5, 1, and 2%, PBO showed a significant synergistic effect with TE toxicity. High levels of esterase activity were associated with the survival of A. aegypti L4 larvae exposed to TE only. Conclusions The results of the biochemical assays suggest that PBO has a significant inhibitory effect on the total esterase activity in A. aegypti larvae. .
Descritores: Aedes/efeitos dos fármacos
Resistência a Inseticidas
Sinergistas de Praguicidas/farmacologia
Butóxido de Piperonila/farmacologia
-Larva/efeitos dos fármacos
Limites: Animais
Responsável: BR1.1 - BIREME

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Texto completo SciELO Brasil
Plapler, Hélio
Texto completo
Id: lil-697552
Autor: Fernandes, Tania Rita Moreno de Oliveira; Santos, Itamar; Korinsfky, Juliana Pedrosa; Silva, Benedyto Savio Lima e; Carvalho, Luis Otavio; Plapler, Helio.
Título: Cutaneous changes in rats induced by chronic skin exposure to ultraviolet radiation and organophosphate pesticide
Fonte: Acta cir. bras;29(1):7-15, 01/2014. tab, graf.
Idioma: en.
Resumo: PURPOSE: To study the possible potentiation of the carcinogenic effects of ultraviolet radiation associated with an organophosphate pesticide. METHODS: Forty Wistar rats were assigned into four groups (n=10 each) randomized according to the procedures: group A received only UVR-B radiation; group B, UVR-B for eight weeks followed by a seven week period of pesticide exposure; group C, UVR-B + pesticide concomitantly: group D, only pesticide application. At the end of the fifth, tenth and fifteenth weeks the animals were photographed. Skin biopsy and histopathological study with Hematoxylin-Eosin were done on the fifteenth week. Statistical analysis with Fisher's and Sign (unilateral) tests, 5% value for significance. RESULTS: Macroscopic lesions in the group A evolved from the erythema to erythema + desquamation. The groups B and C, with the association of two carcinogens, and group D presented evolution to keratosis, with higher incidence in group D. The histology showed a significant increase in the severity of injuries when the UVR-B and the pesticide were applied simultaneously, leading to cellular atypia. CONCLUSIONS: Concurrent association of UVR-B to organophosphate pesticide produced more severe lesions microscopically, although this has not been so apparent macroscopically. In daily practice the clinical evaluation should be complemented with laboratory evaluation. .
Descritores: Organofosfatos/análise
Pele/anatomia & histologia
Radiação Solar/efeitos adversos
Ferimentos e Lesões
Limites: Animais
Responsável: BR1.1 - BIREME

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Id: lil-694370
Autor: Antoni, A Degli; Weimer, LE; Manfredi, R; Fragola, V; Ferrari, C.
Título: A reduced grade of liver fibros-steatosis after raltegravir, maraviroc and fosamprenavir in an HIV/HCV co-infected patient with chronic hepatitis, cardiomyopathy, intolerance to nelfinavir and a marked increase of serum creatine phosphokinase levels probably related to integrase inhibitor use / Grado reducido de fibroesteatosis tras la administración de raltegravir, maraviroc y fosamprenavir en un paciente co-infectado de VIH/VHC con hepatitis crónica, cardiomiopatía, intolerancia al nelfinavir y un aumento pronunciado de los niveles de creatina fosfoquinasa sérica probablemente debido al uso del inhibidor de la integrasa
Fonte: West Indian med. j;61(9):932-936, Dec. 2012. ilus.
Idioma: en.
Resumo: The use of new antiretroviral drugs in HIV infection is particularly important in patients with intolerance or resistance to other antiretroviral agents. Raltegravir and maraviroc represent new, important resources in salvage regimens. A reduced grade of liver fibro-steatosis after a combination of raltegravir and maraviroc (second-line) has not been studied and the mechanism by which these new drug classes induced a marked reduction of grade of liver diseases is currently unknown. In the present case report, nested in an ongoing multicentre observational study on the use of new antiretroviral inhibitors in heavy treatment-experienced HIV patients, we evaluated the correlation between a "short therapeutic regimen" raltegravir, maraviroc and fosamprenavir and liver diseases. The aim of this report is to describe the use of a three-drug regimen based on two novel-class antiretroviral agents (raltegravir and maraviroc) plus the protease inhibitor fosamprenavir, in an experienced HIV-infected patient with chronic progressive hepatitis C complicated by liver fibrosis; an overwhelming increased serum creatine kinase level occurred during treatment, and is probably related to integrase inhibitor administration. At present no information is available regarding this correlation.

El uso de nuevos medicamentos antiretrovirales para la infección por VIH es particularmente importante en los pacientes con intolerancia o resistencia a otros agentes antiretrovirales. Raltegravir (RTV) y maraviroc (MRV) representan nuevos e importantes recursos en las terapias de salvamento. Un grado reducido de fibroesteatosis hepática después de una combinación de raltegravir y maraviroc (terapia de segunda línea) no ha sido estudiado, y el mecanismo por el cual estas nuevas clases de droga indujeron una marcada reducción de grado de las enfermedades hepáticas se desconoce hasta el momento. Como parte de la realización en curso de un estudio observacional multicentro acerca del uso de nuevos inhibidores antiretrovirales en pacientes de VIH altamente experimentados en el tratamiento, en el presente reporte de caso se evalúa la correlación entre un "régimen terapéutico corto" (raltegravir, maraviroc y fosamprenavir) y las enfermedades del hígado. El objetivo de este reporte es describir el uso de un régimen de tres medicamentos - basado en dos agentes antiretrovirales de nuevo tipo (raltegravir y maraviroc) además del fosamprenavir inhibidor de la proteasa - en un paciente de VIH experimentado. El paciente también sufre de hepatitis C evolutiva, progresiva, crónica, complicada por fibrosis hepática. Durante el tratamiento, se produjo un aumento extraordinario del nivel de creatina quinasa sérica, el cual probablemente esta relacionado con la administración del inhibidor de la integrasa. Actualmente no hay información disponible con respecto a esta correlación.
Descritores: Carbamatos/efeitos adversos
Cardiomiopatias/tratamento farmacológico
Creatina Quinase/sangue
Cicloexanos/efeitos adversos
Doença Hepática Induzida por Substâncias e Drogas/diagnóstico
Fígado Gorduroso/induzido quimicamente
Inibidores da Fusão de HIV/efeitos adversos
Infecções por HIV/tratamento farmacológico
Inibidores de Integrase de HIV/efeitos adversos
Inibidores da Protease de HIV/efeitos adversos
Hepatite C Crônica/tratamento farmacológico
Cirrose Hepática/induzido quimicamente
Organofosfatos/efeitos adversos
Pirrolidinonas/efeitos adversos
Sulfonamidas/efeitos adversos
Triazóis/efeitos adversos
-Carbamatos/uso terapêutico
Cicloexanos/uso terapêutico
Substituição de Medicamentos
Quimioterapia Combinada
Fígado Gorduroso/diagnóstico
Inibidores da Fusão de HIV/uso terapêutico
Inibidores de Integrase de HIV/uso terapêutico
Inibidores da Protease de HIV/uso terapêutico
Cirrose Hepática/diagnóstico
Organofosfatos/uso terapêutico
Pirrolidinonas/uso terapêutico
Sulfonamidas/uso terapêutico
Triazóis/uso terapêutico
Limites: Adulto
Seres Humanos
Tipo de Publ: Relatos de Casos
Responsável: BR21.1 - Biblioteca J Baeta Vianna- Campus Saúde UFMG

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Texto completo SciELO Brasil
Texto completo
Id: lil-678338
Autor: Fernandes, Julio I; Verocai, Guilherme G; Ribeiro, Francisco A; Melo, Raquel M. P. S; Correia, Thaís R; Coumendouros, Katherina; Scott, Fabio B.
Título: Efficacy of the d-phenothrin/pyriproxyfen association against mites in naturally co-infested rabbits / Eficácia da associação de d-fenotrina e piriproxifen no controle de ácaros em coelhos naturalmente co-infestados
Fonte: Pesqui. vet. bras = Braz. j. vet. res;33(5):597-600, maio 2013. tab.
Idioma: en.
Resumo: The aim of the present study was to evaluate the efficacy of the d-phenothrin/pyriproxyfen association against Psoroptes ovis, Cheyletiella parasitivorax, and Leporacarus gibbus infestations in naturally co-infested rabbits. Twenty crossbreed (New Zealand White x California) rabbits concurrently infested by the three mite species were randomly divided in two groups. All rabbits presented with hyperemia, erythema and formation of crusts in the ear canals caused by P. ovis. Infestations by both C. parasitivorax and L. gibbus were considered asymptomatic in all animals.Ten animals were treated with a 4.4% d-phenothrin and 0.148% pyriproxyfen spray formulation until have their body surface uniformly sprayed, including external ear canals. The other ten rabbits remained untreated, serving as control group. Observations were done on days +7, +14, +21, +28, and +35 post-treatment. The d-phenothrin/pyriproxyfen association showed 100% efficacy against the three mite species and was responsible for the remission of psoroptic mange lesions on treated animals. No signs of intoxication were observed. The results indicate that d-phenothrin/pyriproxyfen spray formulation in a single application is an effective and clinically safe option for the control of different mite infestations in rabbits.

O objetivo do presente estudo foi avaliar a eficácia da associação de d-fenotrina e piriproxifen no controle de infestações simultâneas por Psoroptes ovis, Cheyletiella parasitivorax e Leporacarus gibbus em coelhos naturalmente co-infestados. Vinte coelhos mestiços (Nova Zelândia Branco x Califórnia) infestados simultaneamente pelas três espécies de ácaros foram divididos aleatoriamente em dois grupos. Todos os coelhos infestados por apresentavam eritema, hiperemia e formação de crostas nas orelhas, causados por P. ovis. Infestações simultâneas por C. parasitivorax e L. gibbus foram considerados assintomáticas em todos os animais. Dez animais foram tratados com uma formulação spray contendo d-fenotrina a 4,4% e piriproxifen a 0,148%, pulverizando toda a superfície corporal de forma uniforme, incluindo a face interna das orelhas. Os outros 10 coelhos não foram t ratados, sendo mantidos como grupo controle. Os animais foram avaliados nos dias 7, 14, 21, 28 e 35 pós-tratamento. A associação de d-fenotrina e piriproxifen foi 100% eficaz no controle das três espécies de ácaros e foi responsável pela remissão das lesões de sarna psoróptica nos animais tratados. Não foram observados sinais de intoxicação. Os resultados indicam que a formulação spray de d-fenotrina e piriproxifen em uma única aplicação é uma opção clinicamente segura e eficaz no controle de infestações por ácaros em coelhos.
Descritores: Ácaros/imunologia
Organofosfatos/uso terapêutico
Resistência a Inseticidas/imunologia
-Infestações por Ácaros/veterinária
Piridinas/administração & dosagem
Controle de Ácaros e Carrapatos
Limites: Animais
Responsável: BR68.1 - Biblioteca Virginie Buff D'Ápice

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Texto completo SciELO Venezuela
Texto completo
Id: lil-659220
Autor: Flores-García, Mery Elisa; Molina-Morales, Yuri; Balza-Quintero, Alirio; Benítez-Díaz, Pedro Rafael; Miranda-Contreras, Leticia.
Título: Residuos de plaguicidas en aguas para consumo humano en una comunidad agrícola del estado Mérida, Venezuela / Pesticide residues in drinking water of an agricultural community in the state of Mérida, Venezuela
Fonte: Invest. clín;52(4):295-311, dic. 2011. ilus, tab.
Idioma: es.
Resumo: El objetivo del presente trabajo fue determinar la presencia de plaguicidas en agua potable, provenientes de seis acueductos en una región de intensa actividad agrícola del Estado Mérida, Venezuela. El estudio fue realizado durante cuatro semanas continuas, entre mayo y junio de 2008. Los residuos de plaguicidas fueron analizados mediante extracción en fase sólida y HPLC con detector de arreglo de diodos. El método SPE-HPLC-DAD cumplió con los criterios de validación analítica: linealidad (R²: 0,9840-0,9999), precisión (coeficiente de variabilidad inter-día 1,47-6,25%), exactitud (desviación estándar relativa 0,9-9,20%) y sensibilidad (límite de detección ≤ 0,012 µg/L; límite de cuantificación ≤ 0,030 µg/L, excepto mancozeb con 0,400 µg/L). Siete de los trece plaguicidas seleccionados tienen un porcentaje de recuperación entre 100% y 70%, el resto, entre 61% y 37%. En 72 muestras analizadas, se detectaron diez plaguicidas de los grupos químicos: organofosforados, carbamatos, triazinas y derivados de urea. Los plaguicidas con mayor frecuencia de detección fueron: carbofuran y atrazina (39%), malation (25%), dimetoato y metribuzin (19%). Los plaguicidas que se encontraron en niveles más altos fueron: diazinon (26,31 µg/L), metamidofos (10,99 µg/L), malation (2,03 µg/L) y mancozeb (1,27 µg/L). Los niveles de plaguicidas no superaron los valores máximos permitidos por la Legislación Venezolana, sin embargo, fueron superiores al nivel máximo permitido por la Unión Europea y EPA-USA. Este estudio demuestra la urgente necesidad de hacer un monitoreo sistemático de la calidad del agua para consumo humano en las regiones de alta productividad agrícola.

The aim of this study was to determine the presence of pesticides in drinking water from six aqueducts in a region of intense agricultural activity in the state of Merida, Venezuela. The study was conducted for four continuous weeks, between May and June 2008. Pesticide residues were analyzed by solid phase extraction (SPE) and liquid chromatography (HPLC) with diode array detector (DAD). The method SPE-HPLC-DAD met the criteria of analytical validation, with good linearity (R²: 0.9840 to 0.9999), precision (coefficient of inter-day variability from 1.47 to 6.25%), accuracy (relative standard deviation 0.9 to 9.20%) and sensitivity (LOD ≤ 0.012 µg/L; LOQ ≤ 0.030 µg/L, except mancozeb with 0.400 µg/L). Seven of the thirteen selected pesticides have a recovery rate between 100% and 70%, the rest between 61% and 37%. Ten pesticides of the following chemical groups, were detected in 72 samples analyzed: organophosphates, carbamates, triazines and urea derivatives. The pesticides with the highest frequency of detection were: carbofuran and atrazine (39%), malathion (25%), dimethoate and metribuzin (19%). The pesticides found at high levels were diazinon (26.31 µg/L), methamidophos (10.99 µg/L), malathion (2.03 µg/L) and mancozeb (1.27 µg/L). Pesticide levels did not exceed the maximum allowed by Venezuelan law, however, according to international standards (EU and EPA-USA) values were above the maximum permissible levels. This study demonstrates the urgent need for systematic monitoring of the quality of water for human consumption in regions of high agricultural productivity.
Descritores: Resíduos de Praguicidas/análise
Poluentes Químicos da Água/análise
Abastecimento de Água/análise
Cromatografia Líquida de Alta Pressão
Concentração Máxima Permitida
Saúde da População Rural
Sensibilidade e Especificidade
Limites: Seres Humanos
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: VE1.1 - Biblioteca Humberto Garcia Arocha

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Texto completo SciELO Brasil
Texto completo
Id: lil-624840
Autor: Guerrero, Felix David; Lovis, Léonore; Martins, João Ricardo.
Título: Acaricide resistance mechanisms in Rhipicephalus (Boophilus) microplus / Mecanismos de resistência aos acaricidas em Rhipicephalus (Boophilus) microplus
Fonte: Rev. bras. parasitol. vet;21(1):1-6, jan.-mar. 2012. tab.
Idioma: en.
Resumo: Acaricide resistance has become widespread in countries where cattle ticks, Rhipicephalus (Boophilus) microplus, are a problem. Resistance arises through genetic changes in a cattle tick population that causes modifications to the target site, increased metabolism or sequestration of the acaricide, or reduced ability of the acaricide to penetrate through the outer protective layers of the tick’s body. We review the molecular and biochemical mechanisms of acaricide resistance that have been shown to be functional in R. (B.) microplus. From a mechanistic point of view, resistance to pyrethroids has been characterized to a greater degree than any other acaricide class. Although a great deal of research has gone into discovery of the mechanisms that cause organophosphate resistance, very little is defined at the molecular level and organophosphate resistance seems to be maintained through a complex and multifactorial process. The resistance mechanisms for other acaricides are less well understood. The target sites of fipronil and the macrocyclic lactones are known and resistance mechanism studies are in the early stages. The target site of amitraz has not been definitively identified and this is hampering mechanistic studies on this acaricide.

A resistência aos acaricidas tornou-se amplamente difundida nos países onde os carrapatos bovinos, Rhipicephalus .Boophilus. microplus, são um problema. A resistência surge por meio de alterações genéticas em umapopulação de carrapatos que causam modificações no local de ação, aumento do metabolismo ou sequestro do acaricida, ou ainda redução na capacidade do acaricida em penetrar através das camadas protetoras do corpo do carrapato. Neste artigo, foram revisados os mecanismos moleculares e bioquímicos da resistência aos acaricidas que ocorrem em R. (B.) microplus. A partir de um ponto de vista dos mecanismos envolvidos, a resistência aos piretróides tem sido caracterizada em maior grau do que em qualquer outra classe de acaricida. Embora uma grande quantidade de pesquisas têm sido direcionada para a descoberta de mecanismos que causam resistência aos organofosforados, muito pouco é conhecido ao nível molecular, e essa resistência parece ser mantida por intermédio de um processo multifatorial e complexo. Os mecanismos de resistência para os demais acaricidas são bem menos compreendidos. Os alvos de ação do fipronil e das lactonas macrocíclicas são conhecidos, e os estudos dos mecanismos de ação envolvidos estão ainda em estágios iniciais. O alvo de ação do amitraz ainda não foi definitivamente identificado, e isso é limitante aos estudos dos mecanismos envolvidos na resistência a esse acaricida.
Descritores: Acaricidas/farmacologia
Rhipicephalus/efeitos dos fármacos
-Resistência a Medicamentos
Limites: Animais
Tipo de Publ: Research Support, U.S. Gov't, Non-P.H.S.
Responsável: BR1.1 - BIREME

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