Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Intervalo de año de publicación
1.
Biotech Histochem ; 94(7): 498-513, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31064227

RESUMEN

Essential oils are a promising alternative to insecticides. We investigated the LD50 of oils extracted from Piper corcovadensis, P. marginatum, and P. arboreum after 48 h topical contact with Spodoptera frugiperda larvae using morphometry, histochemistry and immunohistochemistry of the midgut and fat body. Chromatography revealed that E-caryophyllene was the principal compound common to the Piper species. The essential oils of P. corcovadensis, P. marginatum and P. arboreum caused deleterious changes in the midgut of S. frugiperda larvae. P. corcovadensis oil produced the lowest LD50 and significant histopathological alterations including elongation of the columnar cells, formation of cytoplasmic protrusions, reduction in carbohydrate, increased apoptotic index and decreased cell proliferation. P. arboreum oil caused histopathological alterations similar to P. corcovadensis, but caused the highest rate of cell proliferation and increased regenerative cells, which indicated rapid regeneration of the epithelium. Our findings demonstrated the insecticidal potential of P. corcovadensis for control of S. frugiperda owing to the significant damage it inflicted on S. frugiperda midgut.


Asunto(s)
Cuerpo Adiposo/efectos de los fármacos , Cuerpo Adiposo/patología , Aceites Volátiles/farmacología , Piper/metabolismo , Animales , Sistema Digestivo/metabolismo , Sistema Digestivo/patología , Cuerpo Adiposo/metabolismo , Insecticidas/metabolismo , Insecticidas/farmacología , Larva/efectos de los fármacos , Aceites Volátiles/química , Piper/química , Aceites de Plantas/metabolismo , Aceites de Plantas/farmacología , Spodoptera
2.
J Econ Entomol ; 109(2): 660-6, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26868417

RESUMEN

Spodoptera frugiperda (Smith 1797) (Lepidoptera: Noctuidae) is a major pest of maize, Zea mays L. Its control is often achieved through repeated applications per season of insecticides, which may lead to adverse effects on the ecosystem. Thus, the study of alternative methods with less environmental impact has expanded to include the use of essential oils. These oils are products of the secondary metabolism in plants, and their insecticidal activity has been widely demonstrated in populations of many pest insects. This study evaluated the insecticidal activities of essential oils from Eucalyptus staigeriana, Ocimum gratissimum, and Foeniculum vulgare on Spodoptera frugiperda. Gas chromatography­mass spectrometry profiles and contact toxicity of these oils as well as their sublethal effects on larvae and reproductive parameters in adults were evaluated. All three oils had sublethal effects on S. frugiperda; however, the oil of O. gratissimum showed the best results at all doses tested. These essential oils may have promise for control of S. frugiperda.


Asunto(s)
Eucalyptus/química , Foeniculum/química , Insecticidas/análisis , Ocimum/química , Aceites Volátiles/toxicidad , Spodoptera/efectos de los fármacos , Animales , Aceites Volátiles/química , Reproducción/efectos de los fármacos
3.
J Econ Entomol ; 107(1): 144-53, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24665696

RESUMEN

The combination of essential oils and Bacillus thuringiensis Berliner may represent an interesting control strategy. Thus, the study tested the following hypothesis: the combination of long pepper oil (Piper hispidinervum L.) and clove (Syzygium aromaticum L.) oils in two concentrations with Xentari WG (Bta) yields a more effective control of Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) affecting biological and reproductive parameters and leading to changes in the levels of phenoloxidase and nitric oxide in the hemolymph of the pest. The results demonstrate that only long pepper oil, at the highest concentration with Xentari WG (Bta), promotes reduced larval survival. However, both oils with or without the insecticide interfere in the biology and humoral immunity of S.frugiperda. All treatments caused a decrease in the amount of eggs, except for the clove oil at both concentrations without Bta. Therefore, the use of these oils is a promising alternative for the integrated management of S. frugiperda; however, its association with Bta demonstrated no significant increase in their efficiency.


Asunto(s)
Conducta Alimentaria/efectos de los fármacos , Mariposas Nocturnas/efectos de los fármacos , Aceites Volátiles/toxicidad , Piper/química , Syzygium/química , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas , Endotoxinas , Fertilidad/efectos de los fármacos , Hemolinfa/metabolismo , Proteínas Hemolisinas , Insecticidas , Monofenol Monooxigenasa/metabolismo , Mariposas Nocturnas/enzimología , Mariposas Nocturnas/crecimiento & desarrollo , Óxido Nítrico/metabolismo , Aceites Volátiles/química
4.
Biotech Histochem ; 89(4): 245-55, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24106972

RESUMEN

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3(rd) instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest.


Asunto(s)
Aceites Volátiles/farmacología , Ovario/citología , Piper/química , Espermatocitos/citología , Espermatogénesis/efectos de los fármacos , Spodoptera/citología , Spodoptera/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Ovario/efectos de los fármacos , Control Biológico de Vectores/métodos , Aceites de Plantas/farmacología , Espermatocitos/efectos de los fármacos , Espermatocitos/fisiología , Espermatogénesis/fisiología , Spodoptera/fisiología
5.
Arq. Inst. Biol. (Online) ; 77(4): 643-649, out.-dez. 2010. graf
Artículo en Portugués | VETINDEX, LILACS | ID: biblio-1391936

RESUMEN

Diaphania hyalinata L. (Lepidoptera, Pyralidae) destaca-se como principal praga da família Cucurbitaceae. Este lepidóptero é oligófago de hábito polífago, que desperta largo interesse de estudos da sua ecologia comportamental por motivos de manejo em culturas de grande importância econômica como o meloeiro (Cucumis melo L.). Dada esta situação, trabalhos básicos de entendimento de aspectos da ecologia são necessários para a melhoria das formas de manejo, principalmente no aspecto do monitoramento populacional. Diante disso, a presente pesquisa teve como objetivo verificar se a escolha do hospedeiro exercida por fêmeas de D. hyalinata corresponde ao melhor desempenho da prole e como os hospedeiros influenciam sua dinâmica populacional. Testes de oviposição com chance de escolha foram realizados em melão, melancia, maxixe, bucha, melãode-são-caetano e pepino, para estabelecimento de um ranking de preferência. Para o desempenho das lagartas e reprodução foi escolhido o melão (dentre o mais preferido) e a bucha e o pepino (dentre os hospedeiros menos preferidos). Os resultados suportam a hipótese de que a escolha de hospedeiro é relacionada com o desempenho da prole e que D. hyalinata demonstrou possuir plasticidade ao lidar com diferentes hospedeiros o que pode ser um indicativo de capacidade de adaptação a recursos alimentares que flutuam em termos de qualidade e disponibilidade. No entanto, de modo geral, esta plasticidade tem custos elevados, principalmente em termos reprodutivos.


Diaphania hyalinata L. (Lepidoptera, Pyralidae) stands out as a major pest of the Cucurbitaceae family. This insect is oligophagous with a polyphagous habit, which arouses wide interest in studies of their behavioral ecology for reasons of pest management in crops of high economic importance such as muskmelon (Cucumis melo L.). Given this situation, basic studies aimed at an understanding of ecological aspects of this pest are needed to improve pest management systems, especially in the aspect of population monitoring. Given this, the present study was aimed to determine whether the choice of the host exerted by females of D. hyalinata corresponds to the best performance of the offspring and how the hosts influence their population dynamics. Oviposition-choice tests were performed on melon, watermelon, cucumber, loofah, balsam apple and cucumber, to establish a ranking of preference. For the performance of larvae and reproduction the melon was chosen (among the most preferred hosts) along with loofah and cucumber (among the least preferred hosts). The results support the hypothesis that the choice of host is related to the performance of the offspring and D. hyalinata has demonstrated plasticity in dealing with different hosts which may be indicative of ability to adapt to fluctuating food resources in terms of quality and availability. However, generally this plasticity is expensive, especially in reproductive terms.


Asunto(s)
Cucurbitaceae/parasitología , Cucumis/parasitología , Lepidópteros/parasitología
6.
Clin Genet ; 78(2): 169-74, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20095980

RESUMEN

Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32-79 units. Using a Kaplan-Meier survival analysis, we obtained cumulative probability curves for disease manifestation at a particular age for each CAG repeat length in the 34-45 range. These curves were significantly different (p < 0.001) and showed small overlap. All these information may be very valuable in predictive-testing programs, in the planning of studies for the identification of other genetic and environmental factors as modifiers of age at onset, and in the design of clinical trials for people at enlarged risk for SCA2.


Asunto(s)
Ataxias Espinocerebelosas/epidemiología , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Preescolar , Cuba/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ataxias Espinocerebelosas/genética , Análisis de Supervivencia , Expansión de Repetición de Trinucleótido/genética
7.
J Neurol Neurosurg Psychiatry ; 79(3): 315-7, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17951282

RESUMEN

OBJECTIVE: To evaluate the significance of antigliadin antibodies (AGA) levels for spinocerebellar ataxia type 2. METHODS: We determined AGA levels in 64 patients with spinocerebellar ataxia type 2 and in 65 healthy matched controls. The clinical assessment was carried out using the International Cooperative Ataxia Rating Scale and CAG repeat number was assessed by PCR. RESULTS: Antibodies were positive in 23.4% of the ataxia patients and 9.09% of the controls. Statistical comparison using chi2 test with Yates's correction reveals significant differences between these two groups (chi2 = 3.94; p = 0.047). The same was obtained for strongly positive AGA (chi2 = 4.62; p = 0.032). There were no significant differences between AGA positive and AGA negative patients in age at onset, disease duration, ataxia score or CAG repeat number, neither in the prevalence of gastrointestinal symptoms, prevalence of wheat intolerance or body weight. CONCLUSIONS: These results demonstrate an association between antigliadin antibodies serum levels and SCA2. However, more work has to be done to clarify the clinical consequences of such an association.


Asunto(s)
Anticuerpos/sangre , Gliadina/inmunología , Ataxias Espinocerebelosas/inmunología , Adolescente , Adulto , Anciano , Biomarcadores/sangre , Cuba , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia
8.
J Neurol Neurosurg Psychiatry ; 79: 1-4, 2008. graf, tab
Artículo en Inglés | CUMED | ID: cum-42352

RESUMEN

Antibodies were positive in 23.4 percent of the ataxiapatients and 9.09 percent of the controls. Statistical comparisonusing x2 test with Yatess correction reveals significantdifferences between these two groups (x2=3.94; p=0.047). The same was obtained for strongly positiveAGA (x2=4.62; p=0.032). There were no significant differences between AGA positive and AGA negativepatients in age at onset, disease duration, ataxia score orCAG repeat number, neither in the prevalence of gastrointestinal symptoms, prevalence of wheat intolerance or body weight. These results demonstrate anassociation between antigliadin antibodies serum levels and SCA2. However, more work has to be done to clarify the clinical consequences of such an association...(AU)


Asunto(s)
Humanos , Síndromes de Neurotoxicidad , Glútenes/toxicidad , Gliadina , Ataxias Espinocerebelosas
9.
Plant Cell Rep ; 13(1): 45-8, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24196182

RESUMEN

Anthers of Feijoa sellowiana Berg. (feijoa) produced pollen callus when cultured in Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid and benzyladenine or in nurse cultures. Somatic callus was also formed in large amounts from the connective and from the cut end of the filament. Anthers containing microspores at the stage immediately prior to the first pollen mitosis cultured in the presence of 3% sucrose, presented the highest frequencies of induction. Androgenetic divisions were initiated by the formation of two morphologically equal cells, the so-called B-pathway. Attempts to regenerate pollen plants were unsuccessful but leaf-like structures could be obtained in regeneration media containing combinations of gibberellic acid and benzyladenine.

10.
Pathologica ; 81(1071): 91-5, 1989.
Artículo en Italiano | MEDLINE | ID: mdl-2748212

RESUMEN

Osteoclastoma-like giant cell tumor of lung. A case of osteoclastoma-like giant cell tumor of the lung is reported. This is an unusual tumor too described in the heart, thyroid, skin, soft tissues and pancreas. AA. studied the tumor's structure and are of opinion that it concerns a primitive nonepithelial neoplasm of the lung.


Asunto(s)
Tumores de Células Gigantes/patología , Neoplasias Pulmonares/patología , Adulto , Femenino , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...