Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 240
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
1.
AIDS Behav ; 27(7): 2190-2204, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36881183

RESUMO

Women need multipurpose prevention technologies (MPTs) to simultaneously prevent sexually transmitted infections (STIs), including HIV, with or without contraception. User feedback early in product development is critical for maximizing uptake and continuation. Our global online survey (April 2017-December 2018) explored women's opinions about MPT formulations in development (e.g., fast-dissolving vaginal inserts, vaginal films, intravaginal rings, injectables, implants), preferences for long-acting or "on-demand" methods, and interest in a contraceptive MPT versus products for HIV/STI prevention alone. Of the 630 women in our final analysis (mean 30 years old; range 18-49), 68% were monogamous, 79% completed secondary education, 58% had ≥ 1 child, 56% were from sub-Saharan Africa and 82% preferred a cMPT versus HIV/STI prevention alone. There were no clear preferences for any specific product or product type (long-acting, on-demand, daily). No single product will appeal everyone, however, adding contraception is likely to increase uptake of HIV/STI prevention methods for most women.


RESUMEN: Las mujeres necesitan tecnologías de prevención multipropósito (TPM) para prevenir simultáneamente las infecciones de transmisión sexual (ITS), incluido el VIH, con o sin anticoncepción. Las opiniones de los usuarios cuando un producto comienza a desarrollarse son fundamentales para maximizar la adopción y continuación de dicho producto. Nuestra encuesta global realizada en internet (abril de 2017­diciembre de 2018) exploró las opiniones de las mujeres sobre diferentes fórmulas o dispositivos de TPM que se están desarrollando (ej., insertos vaginales de disolución rápida, láminas vaginales, anillos intravaginales, inyectables, implantes). En esta encuesta se indagó acerca de las preferencias en términos de período de acción (prolongado o breve) y propósito del uso (anticonceptivo, productos para la prevención del VIH/ITS, o ambos). De las 630 mujeres (media de 30 años; rango 18­49) en el análisis final, el 68% eran monógamas, el 79% completaron la educación secundaria, el 58% tenían ≥ 1 hijo, el 56% eran del África subsahariana y el 82% preferían una TPM con componente anticonceptivo en vez de un producto para la prevención de VIH/ITS exclusivamente. No hubo preferencias claras por ningún producto o tipo de producto específico (de acción prolongada, de acción breve, de uso diario). Ningún producto por sí solo logró abarcar todas las preferencias; sin embargo, es probable que la inclusión de métodos anticonceptivos en una TPM aumente el uso de métodos de prevención del VIH/ITS en la mayoría de las mujeres.


Assuntos
Infecções por HIV , Infecções Sexualmente Transmissíveis , Adulto , Feminino , Humanos , Anticoncepção/métodos , Anticoncepcionais , Dispositivos Anticoncepcionais , Infecções por HIV/prevenção & controle , Infecções Sexualmente Transmissíveis/prevenção & controle , Adolescente , Adulto Jovem , Pessoa de Meia-Idade
2.
J Fish Dis ; 40(4): 495-505, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27496636

RESUMO

The potential for developing botanically derived natural products as novel feed-through repellents for disrupting settlement of the salmon louse, Lepeophtheirus salmonis (Caligidae) upon farmed Atlantic salmon, Salmo salar, was investigated using an established laboratory vertical Y-tube behavioural bioassay for assessing copepodid behaviour. Responses to artificial sea water conditioned with the odour of salmon, or to the known salmon-derived kairomone component, α-isophorone, in admixture with selected botanical materials previously known to interfere with invertebrate arthropod host location were recorded. Materials included oils extracted from garlic, Allium sativum (Amaryllidaceae), rosemary, Rosmarinus officinalis (Lamiaceae), lavender, Lavandula angustifolia (Lamiaceae), and bog myrtle, Myrica gale (Myricaceae), and individual components (diallyl sulphide and diallyl disulphide from garlic; allyl, propyl, butyl, 4-pentenyl and 2-phenylethyl isothiocyanate from plants in the Brassica genus). Removal of attraction to salmon-conditioned water (SCW) or α-isophorone was observed when listed materials were presented at extremely low parts per trillion (ppt), that is picograms per litre or 10-12 level. Significant masking of attraction to SCW was observed at a level of 10 ppt for diallyl disulphide and diallyl sulphide, and allyl isothiocyanate and butyl isothiocyanate. The potential of very low concentrations of masking compounds to disrupt Le. salmonis copepodid settlement on a host fish has been demonstrated in vitro.


Assuntos
Copépodes/efeitos dos fármacos , Ectoparasitoses/veterinária , Doenças dos Peixes/tratamento farmacológico , Comportamento de Busca por Hospedeiro/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Salmo salar , Animais , Antiparasitários/farmacologia , Antiparasitários/uso terapêutico , Copépodes/fisiologia , Cicloexanonas/farmacologia , Cicloexanonas/uso terapêutico , Ectoparasitoses/tratamento farmacológico , Ectoparasitoses/parasitologia , Doenças dos Peixes/parasitologia , Isotiocianatos/farmacologia , Isotiocianatos/uso terapêutico , Magnoliopsida/química , Feromônios/farmacologia , Feromônios/uso terapêutico
3.
Ann Appl Biol ; 170(2): 179-188, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28303034

RESUMO

Insect pests can reduce wheat yield by direct feeding and transmission of plant viruses. Here we report results from laboratory and field phenotyping studies on a wide range of wheat, including landraces from the Watkins collection deriving from before the green revolution, more modern cultivars from the Gediflux collection (north-western Europe) and modern UK Elite varieties, for resistance to the bird cherry-oat aphid, Rhopalosiphum padi (Homoptera: Aphididae) and the English grain aphid, Sitobion avenae (Homoptera: Aphididae). A total of 338 lines were screened for R. padi and 340 lines for S. avenae. Field trials were also conducted on 122 Watkins lines to identify wheat bulb fly, Delia coarctata, preference on these landraces. Considerable variation was shown in insect performance among and within different wheat collections, with reduced susceptibility in a number of varieties, but phenotyping did not identify strong resistance to aphids or wheat bulb fly. Field trials showed within collection differences in aphid performance, with fewer aphids populating lines from the Watkins collection. This differs from development data in laboratory bioassays and suggests that there is a pre-alighting cue deterring aphid settlement and demonstrates differences in aphid preference and performance on older plants in the field compared with seedlings in the laboratory, highlighting the need for phenotyping for aphid resistance at different plant growth stages. No association was identified between performance of the different insect species on individual varieties, potentially suggesting different nutritional requirements or resistance mechanisms.

4.
J Chem Ecol ; 42(4): 305-13, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27105878

RESUMO

Previous studies have shown that the boll weevil, Anthonomus grandis, is attracted to constitutive and conspecific herbivore-induced cotton volatiles, preferring the blend emitted by cotton at the reproductive over the vegetative stage. Moreover, this preference was paralleled by the release of the acyclic homoterpenes (tetranorterpenes) (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in Delta Opal cotton being higher at the vegetative than at the reproductive stage. Here, we evaluated whether this difference in release of acyclic homoterpenes also occurred in other cotton varieties, and if boll weevils could recognize these compounds as indicators of a specific cotton phenological stage. Results showed that cotton genotypes CNPA TB-90, BRS-293 and Delta Opal all produced higher levels of DMNT and TMTT at the vegetative stage than at the reproductive stage and that these homoterpenes allowed for principal component analysis separation of volatiles produced by the two phenological stages. Electroantennograms confirmed boll weevil antennal responses to DMNT and TMTT. Behavioral assays, using Y-tube olfactometers, showed that adding synthetic homoterpenes to reproductive cotton volatiles (mimicking cotton at the vegetative stage in terms of homoterpene levels) resulted in reduced attraction to boll weevils compared to that to unmodified reproductive cotton. Weevils showed no preference when given a choice between plants at the vegetative stage and the vegetative stage-mimicked plant. Altogether, the results show that DMNT and TMTT are used by boll weevils to distinguish between cotton phenological stages.


Assuntos
Comportamento Animal/efeitos dos fármacos , Terpenos/química , Terpenos/farmacologia , Gorgulhos/efeitos dos fármacos , Animais , Bioensaio , Feminino , Genótipo , Gossypium/genética , Gossypium/metabolismo , Masculino , Terpenos/metabolismo
5.
Acta Biol Hung ; 65(1): 38-46, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24561893

RESUMO

Hydroxamic acids (HAs) are plant secondary metabolites produced by certain cereals, which have been found to be toxic to pest aphids in artificial diet assays. Previous studies have shown that tetraploid and hexaploid wheat varieties, the leaf tissues of which contained higher levels of these compounds than used in artificial diets, did not reduce aphid settling or fecundity. This current study reports findings on a high HA producing B genome accession of the diploid ancestor of wheat, Aegilops speltoides. We found that this accession does have a negative impact on aphid host selection and substantially reduces nymph production. Whole leaf tissue assays showed very high levels of HAs, well in excess of the toxic level determined in the artificial diet assays. Extraction of the apoplast fluid (AF) from this accession showed that the HA level is much lower than that of the whole tissue, but is still close to the artificial diet toxic level. Furthermore the HA level in the AF increases in response to aphid feeding. These observations could explain why hexaploid wheat remains susceptible to aphids, despite having whole leaf tissue HA levels in excess of the toxic levels determined in artificial diets.


Assuntos
Afídeos/fisiologia , Herbivoria , Ácidos Hidroxâmicos/metabolismo , Triticum/metabolismo , Animais , Antibiose , Diploide , Fertilidade , Folhas de Planta/metabolismo , Poliploidia , Triticum/genética
6.
Commun Agric Appl Biol Sci ; 79(2): 265-77, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-26084106

RESUMO

"Push-Pull" is an inexpensive and eminently practical strategy designed for developing countries in order to exploit sound principles of chemical ecology for agricultural pest management. This strategy is specifically suitable for small holder farmers. Their experience can easily be integrated into existing farming practices in their immediate environment. "Push-pull" within one and a half decades became widely established and meanwhile is greatly beneficial to practitioners in East Africa, mainly Kenya. The classical push-pull approach used for applied plant-insect management was pioneered by Khan and Pickett (2000) and subsequent papers of Pickett (2003) and Khan et al. (2006, 2008). Relevant plant species explored so far were maize or sorghum intercropped with other East African plants (Desmodium spp. resp. Melinis minutiflora) possessing natural chemicals repellent resp. attractive for stem borer moths Chilo partellus (Lepidoptera), whereby Desmodium spp. was grown inside the maize rows while M. minutiflora surrounded it. Both simultaneous actions combined resulted in a significant decrease of stem borers in the area to be protected. A benefit to cost ratio of 2.5 was realized. Within a period of 15 years the number of subscribing farmers substantially increased from a few dozen to more than 80,000 in 2014. Two experiments along the paths of chemical ecology were undertaken between Sept 2012 and Feb 2013: One was designed to investigate if the legume D. intortum known to produce repellent volatiles against stem borer moths induces defence in Zea mays varieties. We looked at two open-pollinated farmers' varieties and two commercial hybrid varieties suspecting the farmers' varieties to be responsive rather than the hybrids. However, no defence induction was detected in this study so far. This could be explained by an insufficient production of defence inducing volatiles in leaves of D. intortum whereas flowers might produce a sufficient response. More detailed study is needed. A second approach made use of species-specific insect monitoring traps baited with highly specific female sex pheromones for attracting and monitoring destructive insect pests. The female sex pheromone (8-methyl-decane-2-ol propanoate) of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) (Western Corn Rootworm) is readily available as bait in the "Metcalf sticky cup trap" for trapping males, an extraordinarily sensitive technique for monitoring the presence or absence of male beetles in a given area. Li et al. (2006) had argued for the likelihood of easy immigration of this cosmopolitan maize pest into East Africa. Our results, however, so far indicate the absence of a local population in the area of Mbita, while not excluding its presence at Nairobi or Mombasa. Both investigations contribute to different aspects of Kenyan economic development and may be seen as two independent but complementary contributions towards livelihood improvement of small holder farmers in Kenya.


Assuntos
Agricultura/métodos , Controle de Insetos/métodos , Controle Biológico de Vetores/métodos , Doenças das Plantas/prevenção & controle , Zea mays/crescimento & desenvolvimento , Animais , Besouros/efeitos dos fármacos , Besouros/fisiologia , Fabaceae/química , Fabaceae/metabolismo , Feminino , Quênia , Masculino , Mariposas/efeitos dos fármacos , Mariposas/fisiologia , Feromônios/farmacologia , Doenças das Plantas/parasitologia , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Zea mays/parasitologia
7.
J Exp Biol ; 216(Pt 3): 460-9, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-22996447

RESUMO

The common bed bug, Cimex lectularius, feeds on the blood of mammal and bird hosts, and is a pest of global importance. Semiochemicals are chemicals involved in animal communication that may affect behaviour and/or physiology. Attractive semiochemicals that play a role in mediating bed bug behaviour could be exploited for the development of a highly effective novel monitoring device. Tracking software was used to record the response of bed bugs to volatiles from paper previously exposed to conspecific bugs in a still-air olfactometer illuminated by infrared lights, through a variety of activity variables. The effect of time of day as an extrinsic factor, and sex, stage, mating status and nutritional status as physiological factors on the response of bed bugs to the volatiles was examined. Bed bugs of both sexes and all stages responded to the volatiles from bed bug-exposed papers, showing significant attraction and orientation towards the volatile source whether they were starved or engorged. Confirmation that the physiological factors examined do not affect the response of bed bugs to the volatiles from bed bug-exposed papers provides evidence that these bed bug-derived volatiles contain aggregation cues, as semiochemicals that promote aggregation should by definition be detected by both sexes and all life stages. A device baited with such semiochemicals could play a major role in limiting the impact of the current bed bug resurgence by enabling timely detection of infestations, along with quantitative evaluation of control and effective surveillance of the geographical distribution of the pest species.


Assuntos
Percevejos-de-Cama/fisiologia , Feromônios/metabolismo , Comunicação Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Desenho de Equipamento , Humanos , Masculino , Odorantes/análise , Comportamento Sexual Animal , Olfato , Volatilização
8.
Med Mycol ; 51(5): 455-60, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23294425

RESUMO

We describe an opportunistic, disseminated infection in a German shepherd dog associated with two fungal organisms not previously reported to cause disease. Lecythophora canina, a new species here described, was isolated from an osteolytic bone lesion. A fine needle aspirate of the lesion demonstrated septate hyphae. Plectospharella cucumerina (anamorph Plectosporium tabacinum) was isolated from a urine sample. Clinical manifestations were blindness, altered mentation, and osteomyelitis. Treatment with itraconazole and terbinafine for greater than one year resulted in stable clinical disease.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Coinfecção/veterinária , Doenças do Cão/microbiologia , Micoses/veterinária , Animais , Ascomicetos/genética , Biópsia por Agulha Fina , Osso e Ossos/diagnóstico por imagem , Coinfecção/microbiologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Cães , Microscopia , Dados de Sequência Molecular , Micoses/microbiologia , Infecções Oportunistas/microbiologia , Infecções Oportunistas/veterinária , Osteomielite/microbiologia , Osteomielite/veterinária , Radiografia , Análise de Sequência de DNA , Urina/microbiologia
9.
J Chem Ecol ; 38(7): 836-45, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22692410

RESUMO

Chinavia and Nezara spp. stink bugs (Heteroptera: Pentatomidae) include over100 species, with highest diversity in Afrotropical and Neotropical regions. Species thus far studied in these genera utilize trans-(Z)-(4 S)-bisabolene epoxide (BE) and cis-(Z)-(4 S)-BE as major sex pheromone components, with species specificity ensured by different ratios of the two compounds. Gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) analyses of a volatiles from C. ubica males revealed the presence of two BE isomers in approximately a 90:10 ratio, which were shown by microprobe (1) H NMR to be cis-(Z)-BE and trans-(Z)-BE isomers, respectively. Analyses of volatiles from C. impicticornis males suggested the presence of a single isomer, trans-(Z)-BE, in high purity (>90 %). The absolute configurations of the isomers produced by C. ubica and C. impicticornis were determined using chiral GC analysis (ß-DEX column). Oxidative microchemistry of synthetic standards of cis-(Z)-(4 S)-BE and trans-(Z)-(4R)-BE, and volatiles from male of C. ubica, revealed the absolute stereochemistry of the cis-(Z)-BE to be (1R,2 S,4 S) [cis-(Z)-(4 S) for short]. Similarly, analyses of trans-(Z)-(4 S)-BE and cis-(Z)-(4R)-BE standards, and volatiles from males of C. ubica and C. impicticornis, revealed the absolute stereochemistry of the trans-(Z)-BE to be (1 S,2R,4 S) [trans-(Z)-(4 S) for short]. Olfactometer bioassays with synthetic BEs confirmed attraction of female C. ubica and C. impicticornis to conspecific synthetic pheromone, but not to heterospecific synthetic pheromone. Chinavia impicticornis appeared not to discriminate behaviorally between the conspecific pheromone and its enantiomer. Coupled GC-electroantennography with antennae from females suggested that C. ubica and C. impicticornis possess olfactory receptors for both cis-(Z)-(4 S)-BE and trans-(Z)-(4 S)-BE. The results in this study confirm that C. ubica and C. impicticornis, as for other Chinavia and Nezara spp., utilize cis-(Z)-(4 S)-BE and trans-(Z)-(4 S)-BE as sex pheromone components, with different ratios guaranteeing species specificity. Furthermore, the results suggest that the absolute stereochemistry of BEs may be less important for conspecific recognition than the relative stereochemistry between the epoxide group and the alkyl substituent on the bisabolene ring.


Assuntos
Comunicação Animal , Heterópteros/fisiologia , Atrativos Sexuais/química , Animais , Antenas de Artrópodes/fisiologia , Feminino , Isomerismo , Masculino , Atrativos Sexuais/fisiologia , Especificidade da Espécie
10.
J Chem Ecol ; 38(12): 1528-38, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23179097

RESUMO

The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by cotton plants enhanced the attractiveness of the aggregation pheromone emitted by male boll weevils. Behavioral responses of A. grandis to VOCs from conspecific-damaged, heterospecific-damaged (Spodoptera frugiperda and Euschistus heros) and undamaged cotton plants, at different phenological stages, were assessed in Y-tube olfactometers. The results showed that volatiles emitted from reproductive cotton plants damaged by conspecifics were attractive to adults boll weevils, whereas volatiles induced by heterospecific herbivores were not as attractive. Additionally, addition of boll weevil-induced volatiles from reproductive cotton plants to aggregation pheromone gave increased attraction, relative to the pheromone alone. The VOC profiles of undamaged and mechanically damaged cotton plants, in both phenological stages, were not different. Chemical analysis showed that cotton plants produced qualitatively similar volatile profiles regardless of damage type, but the quantities produced differed according to the plant's phenological stage and the herbivore species. Notably, vegetative cotton plants released higher amounts of VOCs compared to reproductive plants. At both stages, the highest rate of VOC release was observed in A. grandis-damaged plants. Results show that A. grandis uses conspecific herbivore-induced volatiles in host location, and that homoterpene compounds, such as (E)-4,8-dimethylnona-1,3,7-triene and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene and the monoterpene (E)-ocimene, may be involved in preference for host plants at the reproductive stage.


Assuntos
Gossypium/fisiologia , Feromônios/química , Compostos Orgânicos Voláteis/análise , Gorgulhos/fisiologia , Animais , Comportamento Animal/fisiologia , Cromatografia Gasosa , Gossypium/química , Gossypium/parasitologia , Herbivoria , Terpenos/química
11.
J Med Entomol ; 49(1): 112-21, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22308779

RESUMO

The host kairomones carbon dioxide (CO2) and 1-octen-3-ol elicit a host seeking response in a wide range of haematophagous Diptera. This study investigates the response of Culicoides biting midges (Diptera: Ceratopogonidae) to these cues using field-based experiments at two sites in the United Kingdom with very different species complements. Traps used for surveillance (miniature CDC model 512) and control (Mosquito Magnet Pro) were modified to release ratios of (R)- and (S)-1-octen-3-ol enantiomers in combination with CO2 and, in the case of the latter trap type, a thermal cue. Abundance and species diversity were then compared between these treatments and against collections made using a trap with a CO2 lure only, in a Latin square design. In both habitats, results demonstrated that semiochemical lures containing a high proportion of the (R)-enantiomer consistently attracted a greater abundance of host-seeking Culicoides females than any other treatment. Culicoides collected using an optimal stimulus of 500 ml/min CO2 combined with 4.1 mg/h (R)-1-octen-3-ol were then compared with those collected on sheep through the use of a drop trap. While preliminary in nature, this trial indicated Culicoides species complements are similar between collections made using the drop trap in comparison to the semiochemical-baited CDC trap, and that there are advantages in using (R)-1-octen-3-ol.


Assuntos
Dióxido de Carbono/farmacologia , Ceratopogonidae/efeitos dos fármacos , Controle de Insetos/instrumentação , Octanóis/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Ceratopogonidae/fisiologia , Feminino , Gado , Reino Unido
12.
Vet Ophthalmol ; 15(4): 223-30, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22117605

RESUMO

OBJECTIVE: To immunohistochemically evaluate expression of vascular endothelial growth factor receptor-1 (VEGFR1) and -2 (VEGFR2) in ocular tissue of healthy dogs and dogs affected with primary glaucoma, uveitic glaucoma, and intraocular neoplasia. SAMPLE POPULATION: Enucleated globes from five dogs with primary glaucoma, five dogs with uveitic glaucoma, six dogs with intraocular neoplasms and three ophthalmically normal control dogs. PROCEDURE: Ocular tissues were obtained from enucleated globes of clinical cases or immediately following euthanasia for control dogs. Tissue sections were stained immunohistochemically for VEGFR1 and VEGFR2 via standard techniques and vascular tissue was qualitatively evaluated. Vascular endothelial VEGFR1 and VEGFR2 expression patterns are reported for normal and diseased ocular tissues. In addition, VEGFR1 and VEGFR2 expression patterns are reported for all normal ocular tissues. RESULTS: A constitutive expression pattern was detected for VEGFR1 by ocular vascular endothelial cells as well as nonvascular cells in the cornea, uvea, lens, and retina. VEGFR2 demonstrated limited expression in normal ocular tissue, but was widely expressed in vascular endothelium of diseased eyes, particularly in pre-iridal fibrovascular membranes. CONCLUSIONS: The results of this study suggest a role for VEGF receptors in both physiologic and pathologic angiogenesis in canine ocular tissue. Manipulation of this pathway may be a rational consideration for therapeutic intervention in canine ocular disease exhibiting pathologic neovascularization.


Assuntos
Doenças do Cão/metabolismo , Neoplasias Oculares/veterinária , Olho/metabolismo , Glaucoma/veterinária , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Doenças do Cão/genética , Cães , Neoplasias Oculares/metabolismo , Glaucoma/genética , Glaucoma/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética
13.
Vet Ophthalmol ; 15 Suppl 1: 21-30, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22050642

RESUMO

OBJECTIVE: To examine the concentrations of vascular endothelial growth factor (VEGF) in aqueous humor of dogs with intraocular disease and to evaluate the association of aqueous humor VEGF with pre-iridal fibrovascular membrane (PIFM) formation. PROCEDURES: Two hundred and twenty six aqueous humor samples and 101 plasma samples were collected from 178 dogs with a variety of intraocular diseases (including cataract, primary glaucoma, uveitic glaucoma, aphakic/pseudophakic glaucoma, retinal detachment, lens luxation, and intraocular neoplasia), and aqueous humor was collected from 13 ophthalmically normal control dogs. Systemic disease status and administration of select medications were recorded. Aqueous and plasma VEGF was assayed via enzyme-linked immunosorbant assay validated for canine VEGF. Available histopathology samples were examined for the presence of PIFM. Where present, PIFMs were categorized as none, cellular, vascular or fibrous, and fibrovascular. Data were evaluated by mixed model anova, with application of Tukey-Kramer adjustment for multiple comparisons. RESULTS: There was no association between aqueous humor and plasma VEGF levels. Compared with normal controls, aqueous humor VEGF was significantly elevated for all intraocular diseases (P < 0.05) except for primary and diabetic cataracts. Systemic disease and administered medications had no significant effect on aqueous humor VEGF concentration. Compared to dogs without PIFM, aqueous humor VEGF was significantly higher in dogs with fibrovascular PIFM (P = 0.001), but not cellular (P = 0.1704) or fibrous/vascular PIFM (P = 0.0667). CONCLUSIONS: These findings confirm that VEGF is commonly elevated in aqueous humor of dogs with intraocular disease and likely plays a role in the causation or progression of a variety of intraocular disorders, including the development of PIFM.


Assuntos
Humor Aquoso/química , Doenças do Cão/metabolismo , Oftalmopatias/metabolismo , Neovascularização Patológica/veterinária , Fator A de Crescimento do Endotélio Vascular/análise , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Estudos de Casos e Controles , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Masculino , Neovascularização Patológica/metabolismo , Reprodutibilidade dos Testes
14.
Exp Appl Acarol ; 57(1): 65-74, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22382713

RESUMO

The European and American house dust mites, Dermatophagoides pteronyssinus and D. farinae, have a huge impact upon human health worldwide due to being the most important indoor trigger of atopic diseases such as asthma, rhinitis and atopic dermatitis. Preceding studies have shown that the behavioural response of house dust mites towards volatile chemicals from food sources can be assessed using a Y-tube olfactometer assay. In the current study, we used this assay to investigate, for the first time, the ability of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), known to repel other ectoparasites affecting human and animal health, to interfere with the attraction of D. pteronyssinus and D. farinae towards a standard food source (fish flakes). Two distinct chemotypes (A and B), enriched in the iridoid compounds (4aS,7S,7aR)-nepetalactone and (4aS,7S,7aS)-nepetalactone, and the sesquiterpene (E)-(1R,9S)-caryophyllene, were used. Initial assays with a hexane extract of fish flakes (FF extract) confirmed attraction of mites to this positive control (P < 0.001 and P < 0.05 for D. pteronyssinus and D. farinae respectively), but when presented in combination with either N. cataria chemotype, tested across a range of doses (10, 1, 0.1 and 0.01 µg), decreasing attraction of mites to their food source was observed as the dose augmented. Our study shows that N. cataria, enriched in iridoid nepetalactones and (E)-(1R,9S)-caryophyllene, exhibits potent repellent activity for house dust mites, and has the potential for deployment in control programmes based on interference with normal house dust mite behaviour.


Assuntos
Nepeta/química , Óleos Voláteis/farmacologia , Pyroglyphidae/efeitos dos fármacos , Animais , Dermatophagoides farinae/efeitos dos fármacos , Dermatophagoides farinae/fisiologia , Dermatophagoides pteronyssinus/efeitos dos fármacos , Dermatophagoides pteronyssinus/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Óleos Voláteis/química , Controle de Pragas/métodos , Pyroglyphidae/fisiologia
15.
Pers Soc Psychol Bull ; 48(4): 606-623, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34056978

RESUMO

The idea that increased levels of extraversion are beneficial to well-being is widespread. Drawing on the idea that behaving discordant to one's trait level is demanding and effortful to maintain, and that repeated taxations of one's self-regulatory resources are unpleasant, we examined the relationship between cumulative counterdispositional extraversion and positive feelings. In two experience-sampling (ESM) studies, participants repeatedly rated their level of state extraversion and positive feelings. Results revealed that cumulative positive deviations from one's trait extraversion level were positively associated with positive feelings, whereas cumulative negative deviations were negatively associated with positive feelings. This confirms the idea that, also when looking at cumulative instances of extraversion-related behaviors, higher levels of extraversion go hand in hand with higher levels of positive feelings.


Assuntos
Extroversão Psicológica , Comportamento Social , Afeto , Emoções , Humanos , Personalidade
16.
Bull Entomol Res ; 101(5): 541-50, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21729394

RESUMO

1-Octen-3-ol is a kairomone for many haematophagous insects including mosquitoes. Numerous studies have examined the effects of racemic 1-octen-3-ol; however, few studies have investigated the role of individual enantiomers in relation to mosquito attraction. In the present study, we investigated the behavioural and electrophysiological responses of two mosquito species, Aedes aegypti and Culex quinquefasciatus, to individual enantiomers and mixtures of 1-octen-3-ol, employing a laboratory Y-tube olfactometer and single sensillum recordings. The olfactory receptor neurons of both Ae. aegypti and Cx. quinquefasciatus had a significantly higher response to the (R)-1-octen-3-ol enantiomer compared to the (S)-1-octen-3-ol enantiomer at 10-9 g µl-1 to 10-6 g µl-1. Behaviourally, Ae. aegypti was more responsive to the (R)-1-octen-3-ol enantiomer, showing an increase in flight activity and relative attraction compared to Cx. quinquefasciatus. The (R)-1-octen-3-ol enantiomer caused an increase in activation for Cx. quinquefasciatus. However, the most notable effect was from an (R:S)-1-octen-3-ol mixture (84:16) that caused significantly more mosquitoes to sustain their flight and reach the capture chambers (demonstrated by a reduced non-sustained flight activity), suggesting that it may have a behaviourally excitatory effect. For Cx. quinquefasciatus, a reduced relative attraction response was also observed for all treatments containing the (R)-1-octen-3-ol enantiomer, either on its own or as part of a mixture, but not with the (S)-1-octen-3-ol enantiomer. This is the first time enantiomeric selectivity has been shown for Ae. aegypti using electrophysiology in vivo. The implications of these results for exploitation in mosquito traps are discussed.


Assuntos
Aedes/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Culex/efeitos dos fármacos , Octanóis/farmacologia , Feromônios/farmacologia , Sensilas/efeitos dos fármacos , Animais , Feminino , Voo Animal/efeitos dos fármacos , Octanóis/química , Neurônios Receptores Olfatórios/efeitos dos fármacos , Feromônios/química , Estereoisomerismo
17.
Bull Entomol Res ; 101(1): 1-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20102661

RESUMO

The common bed bug, Cimex lectularius (Hemiptera: Cimicidae), has recently re-emerged in increasing numbers, distribution and intensity of infestation in many countries. Current control relies on the application of residual pesticides; but, due to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour and physiology modifying chemicals) could be exploited for management of bed bugs. However, in order to identify semiochemicals that can be utilised in monitoring or control, a suitable olfactometer is needed that enables the study of the responses of bed bugs to volatile chemicals. Previous studies have used olfactometers that do not separate olfactory responses from responses to physical contact. In this study, a still-air olfactometer was used to measure behavioural responses to different bed bug-derived volatiles presented in an odour pot. Bed bugs were significantly more likely to visit the area above the odour pot first, and more frequently, in the presence of volatiles from bed bug-exposed paper but not in the presence of volatiles from conspecific bed bugs. Bed bug activity was found to be dependent on the presence of the volatiles from bed bug-exposed paper, the time during the scotophase and the sex of the insect being tested. The still-air olfactometer could be used to test putative semiochemicals, which would allow an understanding of their behavioural role in bed bug ecology. Ultimately, this could lead to the identification of new semiochemical tools for bed bug monitoring and control.


Assuntos
Percevejos-de-Cama/química , Bioensaio/métodos , Feromônios/isolamento & purificação , Compostos Orgânicos Voláteis/isolamento & purificação , Animais , Percevejos-de-Cama/fisiologia , Comportamento Animal , Feminino , Controle de Insetos , Masculino , Odorantes
18.
Can J Public Health ; 102(5): 364-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22032103

RESUMO

OBJECTIVES: Walking or cycling to school represents an opportunity for children to engage in physical activity. The study objectives were to: 1) describe active transportation policies, programs, and built environments of Canadian schools and their surrounding neighbourhoods, and 2) document variations based on urban-rural location and school type (primary vs. secondary vs. mixed primary/secondary schools). METHODS: 397 schools from across Canada were studied. A school administrator completed a questionnaire and responses were used to assess schools' policies and programs related to active transportation and the safety and aesthetics of their respective neighbourhoods. Built environment features in a 1 km-radius circular buffer around each school were measured using geographic information systems. RESULTS: Greater than 70% of schools had passive policies (e.g., skateboards permitted on school grounds) and facilities (e.g., bicycle racks in secure area to avoid theft) to encourage bicycle and small-wheeled vehicle use. Less than 40% of schools had active programs designed to encourage active transportation, such as organized 'walk to school' days. Garbage in the streets, crime and substance abuse were barriers in most school neighbourhoods. Approximately 42% of schools were located on high-speed roads not amenable to active transportation and 14% did not have a sidewalk leading to the school. Secondary schools had less favourable active transportation policies/programs and neighbourhood safety/aesthetics compared to primary schools. Rural schools had less favourable built environments than urban schools. CONCLUSION: Canadian children, particularly those from rural areas, face a number of impediments to active transportation as a method of travelling to school.


Assuntos
Ciclismo/estatística & dados numéricos , Instituições Acadêmicas/estatística & dados numéricos , Meios de Transporte/estatística & dados numéricos , Caminhada/estatística & dados numéricos , Canadá , Humanos , Atividade Motora , Características de Residência/estatística & dados numéricos , População Rural/estatística & dados numéricos , Meios de Transporte/legislação & jurisprudência , Meios de Transporte/métodos , População Urbana/estatística & dados numéricos
19.
J Med Entomol ; 47(5): 798-804, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20939374

RESUMO

The American house dust mite, Dermatophagoidesfarinae Hughes, and European house dust mite, Dermatophagoides pteronyssinus Trouessart, are major pests of medical importance throughout the developed world, causing atopic diseases such as asthma, rhinitis, and atopic dermatitis. Previous studies in our laboratory have shown that the behavioral responses of house dust mites toward volatiles from food sources could be assessed using a Y-tube olfactometer assay. The current study used this Y-tube assay to investigate house dust mite pheromones. A hexane extract of D.farinae, along with fractions of the extract prepared by microscale liquid chromatography over Florisil, were tested for behavioral activity. One of the chromatographic fractions was shown to be significantly attractive (P < 0.05) for D. farinae, compared with a solvent control. Coupled gas chromatography-mass spectrometry analysis of this behaviorally active fraction indicated that neryl or geranyl formate was the major component. Peak enhancement by gas chromatography, using authentic samples of the neryl and geranyl isomers prepared in high purity by chemical synthesis, confirmed the identity of the major peak as neryl formate. In Y-tube assays, male and female D. farinae and D. pteronyssinus both were significantly attracted to synthetic neryl formate at doses of 100 and 10 ng, respectively (P < 0.05). No significant differences were found for D. farinae and D. pteronyssinus when synthetic neryl formate and house dust mite extracts containing natural neryl formate were tested at the same level. Dynamic headspace collection of D. farinae and D. pteronyssinus colonies showed that neryl formate was released as a volatile organic compound by both species. Our study shows that neryl formate is an aggregation pheromone for D. farinae and D. pteronyssinus, and has the potential to be used as part of a novel lure-and-kill system for house dust mite control.


Assuntos
Dermatophagoides farinae/fisiologia , Dermatophagoides pteronyssinus/fisiologia , Formiatos/metabolismo , Feromônios/fisiologia , Terpenos/metabolismo , Animais , Comportamento Animal/fisiologia , Feminino , Masculino
20.
Bull Entomol Res ; 100(1): 1-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19302724

RESUMO

Mosquitoes such as Culex quinquefasciatus Say (Diptera: Culicidae) are important vectors of organisms that cause disease in humans. Research into the development of effective standardized odour baits for blood-fed females (oviposition attractants), to enable entomological monitoring of vector populations, is hampered by complex protocols for extraction of physiologically active volatile chemicals from natural breeding site water samples, which have produced inconsistent results. Air entrainment and solvent extraction are technically demanding methods and are impractical for use in resource poor environments where mosquito-borne disease is most prevalent. This study reports the first use of a simple, robust extraction technique, stir bar sorptive extraction (SBSE), to extract behaviourally active small lipophilic molecules (SLMs) present in water samples collected from Cx. quinquefasciatus breeding sites in Tanzania. Extracts from a pit latrine and from a cess pool breeding site attracted more gravid Cx. quinquefasciatus in pair choice bioassays than control extracts, and coupled gas chromatography-electroantennography (GC-EAG) allowed tentative identification of 15 electrophysiologically active chemicals, including the known oviposition attractant, skatole (3-methylindole). Here, we have demonstrated, using simple pair choice bioassays in controlled laboratory conditions, that SBSE is effective for the extraction of behaviourally and electrophysiologically active semiochemicals from mosquito breeding site waters. Further research is required to confirm that SBSE is an appropriate technique for use in field surveys in the search for oviposition cues for Cx. quinquefasciatus.


Assuntos
Técnicas de Química Analítica/métodos , Culex/química , Água Doce/química , Oviposição/fisiologia , Feromônios/isolamento & purificação , Animais , Comportamento Animal/efeitos dos fármacos , Bioensaio/métodos , Cromatografia Gasosa , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Oviposição/efeitos dos fármacos , Feromônios/farmacologia , Tanzânia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA