RESUMO
Despite its theoretical prominence and sound principles, integrated pest management (IPM) continues to suffer from anemic adoption rates in developing countries. To shed light on the reasons, we surveyed the opinions of a large and diverse pool of IPM professionals and practitioners from 96 countries by using structured concept mapping. The first phase of this method elicited 413 open-ended responses on perceived obstacles to IPM. Analysis of responses revealed 51 unique statements on obstacles, the most frequent of which was "insufficient training and technical support to farmers." Cluster analyses, based on participant opinions, grouped these unique statements into six themes: research weaknesses, outreach weaknesses, IPM weaknesses, farmer weaknesses, pesticide industry interference, and weak adoption incentives. Subsequently, 163 participants rated the obstacles expressed in the 51 unique statements according to importance and remediation difficulty. Respondents from developing countries and high-income countries rated the obstacles differently. As a group, developing-country respondents rated "IPM requires collective action within a farming community" as their top obstacle to IPM adoption. Respondents from high-income countries prioritized instead the "shortage of well-qualified IPM experts and extensionists." Differential prioritization was also evident among developing-country regions, and when obstacle statements were grouped into themes. Results highlighted the need to improve the participation of stakeholders from developing countries in the IPM adoption debate, and also to situate the debate within specific regional contexts.
Assuntos
Agricultura/métodos , Países em Desenvolvimento , Controle de Pragas/métodos , Análise de Variância , Análise por Conglomerados , Relações Comunidade-Instituição , Coleta de Dados , Educação , Motivação , Competência Profissional , PesquisaRESUMO
The human intestinal pathogen Giardia lamblia is a flagellated unicellular protozoan with pronounced medical and biological relevance. However, the basic physiology of Giardia trophozoites has been sparsely studied, especially the electrical and ionic properties of their cellular membrane which are virtually unknown. In this study, we were able to record and characterize the macroscopic ionic currents of Giardia trophozoite membrane by electrophysiological methods of the patch clamp technique. Giardia trophozoites showed a high current density (â¼600 pA/pF at -140 mV) that was activated upon hyperpolarization. This current was carried by a chloride-selective channel (I Cl-G) and it was the most important determinant of the membrane potential in Giardia trophozoites. Moreover, this conductance was able to carry other halide anions and the sequence of permeability was Br(-) > Cl(-) ≈ I(-) â« F(-). Besides the voltage-dependent inward-rectifying nature of I Cl-G, its activation and deactivation kinetics were comparable to those observed in ClC-2 channels. Extracellular pH modified the voltage-dependent properties of I Cl-G, shifting the activation curve from a V 1/2 = -79 ± 1 mV (pH 7.4) to -93 ± 2 mV (pH 8.4) and -112 ± 2 mV (pH 5.4). Furthermore, the maximal amplitude of I Cl-G measured at -100 mV showed dependence to external pH in a bell-shaped fashion reported only for ClC-2 channels. Therefore, our results suggest that I Cl-G possesses several functional properties similar to the mammalian ClC-2 channels.
Assuntos
Potenciais de Ação , Canais de Cloreto/metabolismo , Giardia lamblia/metabolismo , Proteínas de Protozoários/metabolismo , Trofozoítos/metabolismo , Canais de Cloro CLC-2 , Cloretos/metabolismo , Giardia lamblia/crescimento & desenvolvimento , Giardia lamblia/fisiologia , Potenciais da Membrana , Trofozoítos/fisiologiaRESUMO
UNLABELLED: One of the main concerns regarding organophosphate pesticides (OP) is their possible toxic effects. Doses that do not produce acute toxicity are capable of altering the structure and biochemistry of different tissues and organs by production of reactive oxygen species (ROS). Curcumin (CUR) is the main substance in Curcuma longa (Zingiberacea) rhizome that has strong antioxidant activity. However, the neuroprotective properties of curcumin against oxidative stress induced by prolonged exposure to parathion (PAR) is not clear. OBJECTIVE: The present work evaluated the protective effect of curcumin against the oxidative damage induced in the rat hippocampus by the OP PAR. METHODS: Forty female Wistar rats were distributed in four groups as follows: exposed to PAR by inhalation (PAR group); pre-treated with CUR and then exposed to PAR by inhalation, (CUR + PAR group); exposed to environmental air and treated with CUR in the food (CUR group); and exposed to environmental air (the control group). At the end of the handling process, the concentration of erythrocyte cholinesterase was monitored, as indicator of PAR intoxication and lipoperoxidation, immunohistochemistry for astrocytes, and activated microglia and apoptosis was determined in the hippocampus. RESULTS: In the present study, we show that the administration of CUR (200 mg/kg body weight) significantly diminished the oxidative damage in the hippocampus of rats exposed to the OP PAR. DISCUSSION: These data suggest that CUR may be an alternative to prevent neurodegenerative damage after pesticide exposure.
Assuntos
Curcumina/farmacologia , Hipocampo/efeitos dos fármacos , Inseticidas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Paration/toxicidade , Extratos Vegetais/farmacologia , Animais , Antioxidantes/farmacologia , Curcuma/química , Feminino , Hipocampo/patologia , Degeneração Neural/prevenção & controle , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
Pig neural cells express glycoproteins with sialylated N-linked oligosaccharide chains (SNOC) which are used by the porcine rubulavirus (PoRv) as receptors. Pig neuronal or glial cell cultures were employed to investigate (a) whether PoRv infects such cells using a molecule expressing SNOC, and (b) the role of viral envelope glycoproteins in establishing the infection. Enriched neuronal or glial cell cultures were exposed to PoRv and infection was detected immunocytochemically. Neuronal cultures prepared from neonatal pigs were treated enzymatically to eliminate sialic acid or N-linked oligosaccharide chains. Primary neural cultures were exposed to anti-HN or anti-F preincubated with PoRv to study the role of the viral glycoproteins. In enriched cultures, PoRv infected neurons and glial cells, and sialic acid expressed in N-linked oligosaccharide chains appeared to play a central role in infection. It was concluded that HN and F viral glycoproteins are required to infect neurons and glial cells.
Assuntos
Neuroglia/virologia , Neurônios/virologia , Infecções por Rubulavirus/veterinária , Rubulavirus/fisiologia , Sialoglicoproteínas/metabolismo , Animais , Encéfalo/citologia , Células Cultivadas , Neuraminidase/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/metabolismo , Receptores Virais/metabolismo , Infecções por Rubulavirus/virologia , Suínos , Doenças dos Suínos/virologia , Proteínas do Core Viral/metabolismoRESUMO
Dietary polyphenolics, such as curcumin, have shown antioxidant and anti-inflammatory effects. Some antioxidants cause DNA strand breaks in excess of transition metal ions, such as copper. The aim of this study was to evaluate the in vitro effect of curcumin in the presence of increasing concentrations of copper to induce DNA damage in murine leukocytes by the comet assay. Balb-C mouse lymphocytes were exposed to 50 microM curcumin and various concentrations of copper (10 microM, 100 microM and 200 microM). Cellular DNA damage was detected by means of the alkaline comet assay. Our results show that 50 microM curcumin in the presence of 100-200 microM copper induced DNA damage in murine lymphocytes. Curcumin did not inhibit the oxidative DNA damage caused by 50 microM H2O2 in mouse lymphocytes. Moreover, 50 microM curcumin alone was capable of inducing DNA strand breaks under the tested conditions. The increased DNA damage by 50 mM curcumin was observed in the presence of various concentrations of copper, as detected by the alkaline comet assay.
Assuntos
Cobre/toxicidade , Curcumina/toxicidade , Dano ao DNA , Animais , Ensaio Cometa , Relação Dose-Resposta a Droga , Feminino , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Se evaluó un método de castración no quirúrgico por inyección intratesticular en lechones de 21 días de edad. Cinco grupos experimentales fueron tratados con diferentes mezclas. Un grupo fue inyectado con formaldehido, xilocaína, epinefrina y propilenglicol (FXEP), otro con xilocaína y propolenglicol (XP), otro con epinefrina y propilenglicol (EP), otro con propilenglicol (P) y otro con formaldehido en solución amortiguadora de fosfatos 0.1 M (F). Se inyectó 1.5 ml de cada mezcla experimental en cada testículo de los lechones según su grupo. El tratamiento EP luego de 30 Días causó necrosis completa, a 90 y 180 días postratamiento se observó fibrosis, lo cual revela probablemente atrofia irreversible de ambos testículos. Asimismo, dichoo tratamiento produjo severa reducción del peso testicular, sin embargo, no se observaron efectos colaterales indeseables. El tratamiento no afectó el peso somático. En los otros grupos experimentales no se obtuvieron resultados satisfactorios sobre la atrofia y reducción de peso testicular. La preparación experimental no es costosa, la técnica de inyección es sencilla y facíl de realizar, y podría ser un modelo rápido y efectivo de castración no quirúrgica. Sin embargo, se encuentra aún en fase experimental.