Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Neotrop Entomol ; 48(2): 260-268, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30238336

RESUMO

Insects of the family Cercopidae are known as spittlebugs or froghoppers and are represented by 62 genera in the Neotropical region. One of these genera is Ocoaxo Fennah, 1968 with 30 species. The most recent species to be accepted into this genus, Ocoaxo costaricanus, was described by Nast (Ann Zool 33:93-101, 1975). Herein, two new species of Ocoaxo from Mexico are described. One of these new species forms a complex together with Ocoaxo assimilis (Walker) and Ocoaxo varians (Stål). The complex has economic importance in the mountainous areas of the states of Puebla and Oaxaca because it attacks Pinus spp. and causes a disorder called "pine decline." Additionally, dichotomous keys were designed to identify the Ocoaxo Fennah groups and also the species of the subgroup bivittus.


Assuntos
Hemípteros/anatomia & histologia , Hemípteros/classificação , Animais , Feminino , Masculino , México , Pinus
2.
Biomed Res Int ; 2016: 3278359, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27747227

RESUMO

Necrotic enteritis (NE) is an important concern in poultry industry since it causes economic losses, increased mortality, reduction of bird welfare, and contamination of chicken products for human consumption. For decades, the use of in-feed antimicrobial growth promoters (AGPs) has been the main strategy to control intestinal pathogens including Clostridium perfringens (CP), the causative agent of NE. However, the use of AGPs in animal diet has been linked to the emergence and transmission of antimicrobial resistance through food-borne microorganisms, which has led to the ban of AGPs in many countries. This scenario has challenged the poultry industry to search for safer alternative products in order to prevent NE. In this context, the utilization of natural plant extracts with antimicrobial properties appears as a promising and feasible tool to control NE in chicken. In this paper, we review the scientific studies analyzing the potential of plant extracts as alternative feed additives to reduce NE in poultry, with focus on two types of plant products that arise as promising candidates: tannins and essential oils. Some of these products showed antimicrobial activity against CP and coccidia in vitro and in vivo and are able to increase productive performance, emulating the bioactive properties of AGPs.


Assuntos
Anti-Infecciosos/uso terapêutico , Infecções por Clostridium/veterinária , Enterite/tratamento farmacológico , Necrose/tratamento farmacológico , Óleos Voláteis/química , Extratos Vegetais/química , Doenças das Aves Domésticas/tratamento farmacológico , Taninos/química , Animais , Antibacterianos/uso terapêutico , Anti-Infecciosos/química , Infecções por Clostridium/tratamento farmacológico , Clostridium perfringens/efeitos dos fármacos , Farmacorresistência Bacteriana , Tolerância a Medicamentos , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Aves Domésticas
3.
PLoS One ; 10(7): e0133861, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26207373

RESUMO

Brevipalpus phoenicis s.l. is an economically important vector of the Citrus leprosis virus-C (CiLV-C), one of the most severe diseases attacking citrus orchards worldwide. Effective control strategies for this mite should be designed based on basic information including its population structure, and particularly the factors that influence its dynamics. We sampled sweet orange orchards extensively in eight locations in Brazil and 12 in Mexico. Population genetic structure and genetic variation between both countries, among locations and among sampling sites within locations were evaluated by analysing nucleotide sequence data from fragments of the mitochondrial cytochrome oxidase subunit I (COI). In both countries, B. yothersi was the most common species and was found in almost all locations. Individuals from B. papayensis were found in two locations in Brazil. Brevipalpus yothersi populations collected in Brazil were more genetically diverse (14 haplotypes) than Mexican populations (four haplotypes). Although geographical origin had a low but significant effect (ca. 25%) on the population structure, the greatest effect was from the within location comparison (37.02 %). Potential factors driving our results were discussed.


Assuntos
Citrus/virologia , Variação Genética , Insetos Vetores/genética , Ácaros/genética , Doenças das Plantas/virologia , Animais , Brasil , Haplótipos , México , Ácaros/virologia
4.
BMJ Case Rep ; 20142014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-25035442

RESUMO

We present a case of a 67-year-old man who was an active smoker, with a clinical history of ischaemic cardiopathy, hypertension, who presented to the emergency room with hoarseness of voice of 2 weeks duration. No other neurological or cardiorespiratory symptoms were found. Physical examination revealed an aortic regurgitation murmur with radial pulse difference between the upper limbs and femoral pulse difference on lower limbs. Laryngoscopy examination revealed a left vocal cord paralysis in the paramedian position, without signs of malignancy. Thoracoabdominal CT angiography was performed to rule out an aortic dissection. CT revealed a dissection in the descending thoracic aortic arch and abdominal aorta. Cardiovascular surgery was consulted and decided to place endoprosthesis at the thoracic and abdominal aortic area. Hoarseness eventually resolved during the following weeks. Ortner's syndrome is described as hoarseness of voice caused by compression of the left recurrent laryngeal nerve of cardiovascular origin.


Assuntos
Aneurisma da Aorta Torácica/diagnóstico , Dissecção Aórtica/diagnóstico , Rouquidão/patologia , Laringoscopia , Nervo Laríngeo Recorrente/patologia , Tomografia Computadorizada por Raios X , Paralisia das Pregas Vocais/patologia , Idoso , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/patologia , Angiografia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/patologia , Diagnóstico Diferencial , Rouquidão/diagnóstico por imagem , Rouquidão/etiologia , Humanos , Masculino , Prognóstico , Síndrome , Resultado do Tratamento , Paralisia das Pregas Vocais/etiologia
5.
Mol Psychiatry ; 19(6): 682-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23857120

RESUMO

To identify loci associated with Alzheimer disease, we conducted a three-stage analysis using existing genome-wide association studies (GWAS) and genotyping in a new sample. In Stage I, all suggestive single-nucleotide polymorphisms (at P<0.001) in a previously reported GWAS of seven independent studies (8082 Alzheimer's disease (AD) cases; 12 040 controls) were selected, and in Stage II these were examined in an in silico analysis within the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium GWAS (1367 cases and 12904 controls). Six novel signals reaching P<5 × 10(-6) were genotyped in an independent Stage III sample (the Fundació ACE data set) of 2200 sporadic AD patients and 2301 controls. We identified a novel association with AD in the adenosine triphosphate (ATP) synthase, H+ transporting, mitochondrial F0 (ATP5H)/Potassium channel tetramerization domain-containing protein 2 (KCTD2) locus, which reached genome-wide significance in the combined discovery and genotyping sample (rs11870474, odds ratio (OR)=1.58, P=2.6 × 10(-7) in discovery and OR=1.43, P=0.004 in Fundació ACE data set; combined OR=1.53, P=4.7 × 10(-9)). This ATP5H/KCTD2 locus has an important function in mitochondrial energy production and neuronal hyperpolarization during cellular stress conditions, such as hypoxia or glucose deprivation.


Assuntos
Doença de Alzheimer/genética , Translocases Mitocondriais de ADP e ATP/genética , Idoso de 80 Anos ou mais , Estudos de Coortes , Simulação por Computador , Feminino , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
6.
J Appl Microbiol ; 111(4): 939-48, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21722279

RESUMO

AIMS: To evaluate different entomopathogenic fungal isolates against the cactus weevil Metamasius spinolae under laboratory and field conditions, and select an isolate to be used as a tool in the management of this insect pest. METHODS AND RESULTS: Four experiments were carried out. The effect of temperature on the in vitro growth of eight isolates of entomopathogenic fungi (two Metarhizium anisopliae and six Beauveria bassiana) was assessed. The susceptibility of adult M. spinolae to the same isolates was evaluated. Using three selected isolates, the interaction between susceptibility and sex of the insect was studied. Finally, a field experiment was carried out to evaluate infection of adult M. spinolae by the same three isolates under natural abiotic conditions. Overall, growth rate was greatest at 25°C for all the isolates. In vitro growth of M. anisopliae was greater than B. bassiana. Mortality of adult M. spinolae was greater when inoculated with B. bassiana compared with isolates of M. anisopliae. Susceptibility had no interaction with the sex of the insect. The proportion of insects succumbing to infection was smaller when incubated under field conditions than when incubated under laboratory conditions. CONCLUSIONS: The experiments described here showed a complex interaction between entomopathogenic fungi and M. spinolae, and these data allows us to select isolate Bb107 as a first step towards its use in the management of this pest insect. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results showed that entomopathogenic fungi can be used for the control of M. spinolae, which may help reduce the use of chemical insecticides and, therefore, the exposure of Opuntia ficus-indica producers to pesticides.


Assuntos
Beauveria/patogenicidade , Cactaceae/parasitologia , Metarhizium/patogenicidade , Controle Biológico de Vetores/métodos , Gorgulhos/microbiologia , Animais , Beauveria/crescimento & desenvolvimento , Feminino , Masculino , Metarhizium/crescimento & desenvolvimento , Temperatura
7.
Diaeta (B. Aires) ; 29(134): 23-28, ene.-mar. 2011. graf
Artigo em Espanhol | LILACS | ID: lil-591563

RESUMO

Introducción: La inulina es un prebiótico que posee propiedades nutricionales y tecnológicas, pudiéndose adicionar en productos como los helados. El objetivo del trabajo fue formular un helado dietético sabor arándano (reducido en calorías, valor glucídico y lipídico) con características prebióticas, evaluarlo sensorialmente y analizar su composición físico-química.Material y métodos: Se trabajó con inulina en polvo; leche en polvo descremada; aditivos; clara de huevo deshidratada, arándanos escaldados y procesados. Se elaboraron helados al 20, 40 y 60% de arándanos, para definir porcentaje a utilizar mediante prueba de preferencia (Newel y Mac Farlane). Se mezcló, pasteurizó (63ºC; 30 min), enfrió (4°C; 4,5 min), maduró (4ºC; 2 hs) batió y congeló en máquina heladora (-6ºC; 50 min). Posteriormente se envasó y almacenó (-16ºC; 12 hs). El helado preferido se evaluó sensorialmente mediante aceptabilidad. Se realizaron análisis químicos de humedad; proteína; hidratos de carbono; fibra dietética total; cenizas; calcio; sodio; fósforo y físico: overrun. El rótulo se diseñó según CAA. Resultados: La aceptabilidad se expresó en porcentaje y las determinaciones en promedio y desvío estándar. La concentración de fruta preferida fue 40%. Aceptabilidad 86%. El color atractivo, morado; sabor y aroma dulce-ácido, a arándano; textura cremosa, sin cristales de hielo; consistencia, firme, de fundición lenta y cuerpo, esponjoso. Humedad 68,13; proteína 8,4; Hidratos de carbono 10,51; Fibra Dietética Total 12,51; Insoluble 5,82; Soluble 6,69; cenizas 0,45 g%; calcio 148,56; sodio 133,96 y fósforo 167,50 mg%; overrun 71% respectivamente. Se rotuló: “alimento dietético de valor calórico reducido”; “0% grasas”; “sin agregado de azúcar” y “alto contenido en fibra alimentaria”.Conclusiones: El Helado Dietético Arándano, (reducido en calorías, valor glucídico y lipídico) con inulina fue factible, presentando buenas características nutricionales y sensoriales.


Assuntos
Alimentos , Alimentos Formulados , Sorvetes
8.
Artigo em Espanhol | LILACS | ID: lil-627532

RESUMO

Al tallar un lecho óseo, por varias razones, puede quedar una preparación de mayor diámetro al del implante que será insertado, en esta situación no es posible roscarlo en el hueso, ya que este tornillo de titanio no logra estabilidad inicial; cuando esto ocurre, es necesario el uso de cilindros roscados de titanio de mayor diámetro. En caso de no contar con este tornillo de diámetro mayor, podemos colocar en el lecho óseo el implante que queda suelto, y una cuña de titanio puede ser introducida fuertemente entre este y la pared alveolar, logrando de esta manera la estabilidad inicial requerida para conseguir la oseointegración deseada.


When ridge bone perforations, for any reason, result wider than implant diameter, we may not be able to fix the fixture into bone walls. When this happens it becomes necessary to use a larger diameter titanium cylinder. In this article we propose, instead of using a wider titanium cylinder, the use of mini titanium wedges which can be pushed strongly between implant and bone walls, to keep fixture still while oseointegration takes place.


Assuntos
Humanos , Implantação Dentária/métodos , Osseointegração , Titânio/uso terapêutico
9.
Bull Environ Contam Toxicol ; 82(5): 538-42, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19266135

RESUMO

The acute toxicity of glyphosate herbicide was tested on the four species of freshwater phytoplankton, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila. Herbicide concentrations eliciting a 50% growth reduction over 72 h (EC(50)) ranged from 24.5 to 41.7 mg L(-1), whilst a 10% growth inhibition is achieved by herbicide concentrations ranging from 1.6 to 3.0 mg L(-1), difficult to find neither in paddy fields (it is not used in rice) nor in the lake of the Albufera Natural Park. Chorella species are less sensitive to the herbicide than Scenedesmus species. It can be concluded that glyphosate has a low potential risk for the tested organisms.


Assuntos
Água Doce/química , Glicina/análogos & derivados , Herbicidas/toxicidade , Fitoplâncton/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Bioensaio , Glicina/análise , Glicina/toxicidade , Herbicidas/análise , Fitoplâncton/crescimento & desenvolvimento , Espanha , Testes de Toxicidade , Poluentes Químicos da Água/análise , Glifosato
10.
J Viral Hepat ; 16(5): 332-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19228286

RESUMO

Hepatitis C virus (HCV) hypervariable region 1 (HVR1) is the most variable region of the viral genome and its heterogeneity reflects the virus-host interplay during chronicity. Paediatric HCV-infected patients develop liver disease with typical clinical features. Here, the evolution of HVR1 and its adjacent regions were ascertained in plasma samples of two HCV-positive children during a 5-year follow-up period. We report an almost complete conservation of the HVR1 amino acid sequence over time, with underlying nucleotide variability both within and outside HVR1, suggesting some kind of constraint on virus evolution, particularly within HVR1. Although overall d(N)/d(S) rates [rates of nonsynonymous nucleotide substitutions per nonsynonymous site (d(N)) and synonymous nucleotide substitutions per synonymous site (d(S))] were <1 in both patients, a high resolution analysis of selection pressures exerted at the codon level revealed few sites subject to selection and an absolute predominance of invariable positions within HVR1. The HVR1 amino acid sequences showed the antigenic properties expected for this region. Taken together, these data suggest peculiar evolutionary dynamics in our patients, which could be attributed to a mechanism of nucleotide invariability along with purifying selection operating on the HVR1. The lack of HVR1 variability may reflect the adaptation of the virus to a particular environment within each patient or a phenomenon of immune tolerance generated in these immunocompetent patients earlier in life.


Assuntos
Evolução Molecular , Hepacivirus/genética , Hepatite C Crônica/virologia , Mutação de Sentido Incorreto , Mutação Puntual , Sequência de Aminoácidos , Pré-Escolar , Sequência Conservada , Seguimentos , Hepacivirus/imunologia , Hepatite C Crônica/imunologia , Humanos , Dados de Sequência Molecular , Plasma/virologia , Seleção Genética , Análise de Sequência de DNA
11.
Chemosphere ; 67(11): 2221-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17270238

RESUMO

A new Aeromonas bioassay is described to assess the potential harmful effects of the glyphosate-based herbicide, Roundup, in the Albufera lake, a protected area near Valencia. Viability markers as membrane integrity, culturability and beta-galactosidase production of Aeromonas caviae were studied to determine the influence of the herbicide in the bacterial cells. Data from the multifactor analysis of variance test showed no significant differences (P>0.05) between A. caviae counts of viability markers at the studied concentrations (0, 50 and 100 mg l-1 of glyphosate). The effects of Roundup on microbial biota present in the lake were assessed by measuring the number of indigenous mesophilic Aeromonas in presence of different amounts of the herbicide at 0, 50 and 100 mg l-1 of glyphosate. In samples containing 50 and 100 mg l-1 of glyphosate a significant (P<0.05) increase in Aeromonas spp. counts and accompanying flora was observed. The acute toxicity of Roundup and of Roundup diluted with Albufera lake water to Microtox luminescent bacterium (Vibrio fischeri) also was determined. The EC50 values obtained were 36.4 mg l-1 and 64.0 mgl-1 of glyphosate respectively. The acidity (pH 4.5) of the herbicide formulation was the responsible of the observed toxicity.


Assuntos
Bactérias/efeitos dos fármacos , Água Doce/microbiologia , Glicina/análogos & derivados , Herbicidas/toxicidade , Microbiologia da Água , Aeromonas/efeitos dos fármacos , Aeromonas/crescimento & desenvolvimento , Bactérias/crescimento & desenvolvimento , Bioensaio , Cromatografia Gasosa , Contagem de Colônia Microbiana , Glicina/toxicidade , Concentração de Íons de Hidrogênio , Glifosato
12.
Environ Res ; 99(3): 413-24, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16307984

RESUMO

The purpose of this study was to evaluate exposure conditions and acute health effects in subjects participating in the Prestige oil spill cleanup activities and the association between these and the nature of the work and use of protection devices in the regions of Asturias and Cantabria (Spain). The sample comprised 400 subjects in each region, selected from a random sampling of all persons involved in cleanup activities, stratified by type of worker and number of working days. Data were obtained via a structured questionnaire and included information on specific tasks, number of working days, use of protective materials, and acute health effects. These effects were classified into two broad groups: injuries and toxic effects. Data analysis was performed using complex survey methods. Significant differences between groups were evaluated using Pearson's chi(2) test. Unconditional logistic regression was used to compute odds ratios and 95% confidence intervals. Bird cleaners accounted for the highest prevalence of injuries (19% presented with lesions). Working more than 20 days in highly polluted areas was associated with increased risk of injury in all workers. Occurrence of toxic effects was higher among seamen, possibly due to higher exposure to fuel oil and its components. Toxic effects were more frequent among those working longer than 20 days in highly polluted areas, performing three or more different cleaning activities, having skin contact with fuel oil on head/neck or upper limbs, and eating while in contact with fuel or perceiving disturbing odors. No severe disorders were identified among individuals who performed these tasks. However, potential health impact should be considered when organizing cleanup activities in similar environmental disasters.


Assuntos
Poluentes Ambientais/intoxicação , Nível de Saúde , Exposição Ocupacional , Petróleo/intoxicação , Acidentes , Adolescente , Adulto , Animais , Aves , Poluentes Ambientais/isolamento & purificação , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Ocupações , Odorantes , Roupa de Proteção , Análise de Regressão , Espanha
13.
Chemosphere ; 60(11): 1542-9, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16083760

RESUMO

Bottom sediment samples from 121 sites of the Lake Albufera of Valencia were analyzed. Dieldrin, endrin, heptachlor and op'-DDT were not detected (<0.01 ng g(-1)) in 88-93% of the sites. Aldrin and HCB concentration ranges were between <0.01 and 0.1 ng g(-1) in 86% and 94% of the sites, respectively. Heptachlor-epoxide and lindane 95% confidence intervals were 0.2-0.5 and 0.06-0.12, respectively. The greatest average concentration corresponds to pp'-DDE, pp'-DDD and pp'-DDT. The sum of six isomers and derivatives of the DDT average concentration reaches 2.1 ng g(-1), as opposed to 2.7 ng g(-1) for the sum of 13 pesticides considered. In the site with a major contamination, 27.0 ng g(-1) of pp'-DDD and 12.8 ng g(-1) of pp'-DDT were accumulated. The DDE:DDT proportion average was 0.37, indicating an aged DDT contamination. Concentrations of pesticides in sediments were compared to three sediment quality guidelines, and indicated that a low biological effects level can be expected in either sediments or aquatic organisms.


Assuntos
Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , DDT/análise , Diclorodifenil Dicloroetileno/análise , Diclorodifenildicloroetano/análise , Ecossistema , Fungicidas Industriais/análise , Inseticidas/análise , Praguicidas/toxicidade , Espanha
14.
Chemosphere ; 56(4): 315-20, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15183992

RESUMO

The Albufera Natural Park situated in Valencia (Spain), with a very rich flora and fauna is surrounded by rice fields in which pesticide spraying is a regular practice. With this in mind, the sensitivity of four algal species, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris and Chlorella saccharophila to pesticides propanil, tebufenozide and mefenacet was studied using single species toxicity tests. Organisms were exposed to different concentrations of these herbicides and the algal growth was measured in a microplate reader at 410 nm, at 0, 24, 48 and 72 h. Tebufenozide appeared to be the most inhibitory to Scenedesmus and Chlorella species growth. 72 h EC50 of propanil, tebufenozide and mefenacet ranged from 0.29 to 5.98 mg/l, 0.12 to 0.15 mg/l and from 0.25 to 0.67 mg/l, respectively for the four algal species. The two species of Chlorella were more tolerant than the two species of Scenedesmus.


Assuntos
Acetanilidas , Clorófitas/efeitos dos fármacos , Inseticidas/toxicidade , Fitoplâncton/efeitos dos fármacos , Acetamidas/toxicidade , Benzotiazóis , Clorófitas/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Água Doce , Hidrazinas/toxicidade , Dose Letal Mediana , Fitoplâncton/crescimento & desenvolvimento , Propanil/toxicidade , Espanha , Tiazóis/toxicidade , Fatores de Tempo
15.
Chemosphere ; 44(8): 1775-81, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11534908

RESUMO

The acute toxicity of the insecticide and acaricide pyridaphenthion to five species of freshwater phytoplankton, Scenedesmus acutus, Scenedesmus subspicatus, Chlorella vulgaris, Chlorella saccharophila and Pseudanabaena galeata was determined. Insecticide concentrations eliciting a 50% growth reduction over 96 h (EC50) ranged from 2.2 to 30.9 mg/l. The two species of Chlorella and the cyanobacteria P. galeata were more tolerant than the two species of Scenedesmus. Concentrations of pyridaphenthion detected in some natural waters were less than the toxic threshold for these species.


Assuntos
Inseticidas/toxicidade , Compostos Organotiofosforados/toxicidade , Fitoplâncton/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Relação Dose-Resposta a Droga , Dose Letal Mediana , Dinâmica Populacional
16.
Environ Toxicol ; 16(4): 314-20, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11501280

RESUMO

The acute toxicity of the insecticide fenitrothion was measured using four freshwater algae (Chlorella saccharophila, Chlorella vulgaris, Scenedesmus acutus, and Scenedesmus subspicatus) and one cyanobacteria (Pseudanabaena galeata). Insecticide concentrations eliciting 50% growth reduction over 96 hr (EC50) ranged from 0.84 to 11.9 mg/L. Fenitrothion was more toxic than other pesticides studied with the same algal species such as chlorsulfuron, molinate, and pyridaphenthion. The transformation of effective concentrations of fenitrothion and other pesticides obtained from toxicity measurements into percent of the saturation level in water is used as a first evaluation of potential hazard to aquatic systems. The insecticides fenitrothion and pyridaphenthion were less hazardous than the herbicides atrazine, benthiocarb, cinosulfuron, chlorsulfuron, methyl-bensulfuron, and molinate. The two species of Chlorella and the cyanobacterium Pseudanabaena were more tolerant to fenitrothion than the two species of Scenedesmus.


Assuntos
Fenitrotion/efeitos adversos , Inseticidas/efeitos adversos , Fitoplâncton/efeitos dos fármacos , Poluentes Químicos da Água/efeitos adversos , Relação Dose-Resposta a Droga , Dose Letal Mediana , Fitoplâncton/crescimento & desenvolvimento , Medição de Risco
17.
Chemosphere ; 43(3): 321-5, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11302577

RESUMO

A study was undertaken to examine the uptake of the organophosphate insecticide pyridaphenthion in the chlorophyta Chlorella saccharophila. Algae cultures were exposed to the initial nominal concentration 10.0 mg l(-1) pyridaphention during seven days. The insecticide bioconcentrates in the biomass to the highest level of 441.5 +/- 25.9 mg kg(-1) on the fifth day of exposure and was followed by a decrease to 76.6 +/- 5.1 mg kg(-1) on the seventh day. A model was constructed to describe the dynamic process, which estimated a bioconcentration factor (BCF) equal to 28. The study demonstrates the potential of accumulation of pyridaphenthion in aquatic organisms and helps to expand the pyridaphenthion toxicity database. The replacement of fenitrothion by pyridaphenthion concerning their use in rice flooded cultures is discussed.


Assuntos
Biomassa , Chlorella/metabolismo , Monitoramento Ambiental/métodos , Inseticidas/farmacocinética , Compostos Organotiofosforados/farmacocinética , Absorção , Inseticidas/metabolismo , Inseticidas/toxicidade , Modelos Biológicos , Compostos Organotiofosforados/metabolismo , Compostos Organotiofosforados/toxicidade , Farmacocinética
19.
J Basic Microbiol ; 39(3): 143-53, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10427735

RESUMO

A group of 49 strains of Fusarium sp. isolated from different Spanish samples of cereals and mixed feedstuffs were screened for their ability to produce trichothecenes like T-2 toxin (T-2), HT-2 toxin (HT-2), diacetoxyscirpenol (DAS) and deoxynivalenol (DN), as well as other mycotoxin produced by Fusarium named fusarin C. The production of these mycotoxins was analyzed by means of spectrophotometry, thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and gas chromatography (GC). Results showed that from 19 Fusarium strains in which cultures trichothecene production was detected, 15 were HT-2 producers, 9 T-2 producers, 14 DAS producers and 10 DN producers. On the other hand, from 28 Fusarium strains in which cultures fusarin C production was detected, 22 were low fusarin C producers (ranged from 0.04 to 1 microgram/l ICI medium), 5 Fusarium strains were intermediate-level producers (ranged from 1 to 10 micrograms/l ICI medium) and one Fusarium strain produced 240 micrograms/l ICI medium. The identified Fusarium strains that produced trichothecenes and fusarin C were F. moniliforme and F. oxysporum.


Assuntos
Fusarium/metabolismo , Polienos/metabolismo , Tricotecenos/metabolismo , Cromatografia Gasosa , Cromatografia em Camada Fina , Grão Comestível/microbiologia , Fusarium/crescimento & desenvolvimento , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...