Efectos indirectos de insecticidas convencionales y biorracionales sobre la alimentación de Rachiplusia nu (Lepidoptera: Noctuidae)

La evaluación conjunta de los efectos letales y subletales de insecticidas sobre plagas, permite alcanzar un mejor conocimiento de su eficacia de acción. En este sentido, la alteración de los patrones de consumo foliar de una plaga, es un importante punto final para analizar la efectividad de insecticidas sobre insectos fitófagos. Los insecticidas que interfieren con el normal comportamiento alimentario de un insecto plaga contribuyen en el manejo de su población. El objetivo del presente estudio fue evaluar el efecto del endosulfán, cipermetrina, spinosad y metoxifenocida sobre el comportamiento alimentario de Rachiplusia nu, plaga potencial de varios cultivos, en especial soya, a través de experimentos de elección en laboratorio (Centro de Investigaciones del Medio Ambiente (CIMA) La Plata, Argentina). Además, se evaluó la supervivencia de las larvas expuestas a dichos productos. La cipermetrina y el spinosad indujeron efectos antialimentarios sobre las larvas tratadas. El endosulfán no causó efectos significativos sobre este punto final, mientras que las larvas expuestas a metoxifenocida mostraron preferencia por las hojas tratadas. Los insecticidas biorracionales ocasionaron mayor mortalidad sobre R. nu que los convencionales. Estos resultados aportan conocimientos básicos para redefinir estrategias de control.The assessment of sublethal and lethal effects of insecticides on pests allows obtaining further insight of their efficacy. In this way, the pest feeding pattern is a relevant toxicological endpoint to analyze the effectiveness of insecticides on phytophagous insects, due to insecticides that interfere with the normal feeding behavior of a pest contributing to its population management. The objective of the present study was evaluating the effects of endosulfan, cypermethrin, spinosad and methoxyfenozide on feeding pattern of Rachiplusia nu, a potential pest in several crops but mainly in soybean, using laboratory choice test (Centro de Investigaciones del Medio Ambiente (CIMA) La Plata, Argentina). Additionally, the larval survival was also assessed. Cypermethrin and spinosad induced antifeedant effects on exposed larvae. Endosulfan did not cause significant effects, while larvae exposed to methoxyfenozide showed preference towards the treated leaves. Biorational insecticides showed higher mortality to R. nu control than conventional ones. These new insights contribute with knowledge for redefining effective pest control strategies.Fil: Rimoldi, Federico. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fogel, Marilina Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); ArgentinaFil: Schneider, Marcela Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); ArgentinaFil: Ronco, Alicia Estela. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Comparative susceptibility of two Neotropical predators, Eriopis connexa and Chrysoperla externa, to acetamiprid and pyriproxyfen: short and long-term effects after egg exposure

Compatibility assessments between selective insecticides and the natural enemies of pests are essential for integrated-pest-management programs. Chrysoperla externa and Eriopis connexa are two principal Neotropical predators of agricultural pests whose conservation in agroecosystems requires a toxicity evaluation of pesticides to minimize the impact on those beneficial insects on the environment. The objective of this work was to evaluate the toxicity of the insecticides pyriproxyfen and acetamiprid on C. externa and E. connexa eggs exposed to the maximum recommended field concentrations of each along with three successive dilutions. The survival and the immature developmental time were assessed daily until adulthood and the mean survival time calculated over a 10-day period. The cumulative survival of E. connexa was reduced at all concentrations of both insecticides, while that of C. externa was significantly decreased by ≥50 mg L-1 of acetamiprid and ≥37.6 mg L-1 of pyriproxyfen. In both species, the reductions occurred principally on the eggs and first larval instar. Survival curves, in general, differed from those of the controls, with the mean survival time of E. connexa being significantly shorter in insecticides treatments than that of the controls. Certain concentrations of each of the insecticide lengthened the egg and first-larval-instar developmental periods of E. connexa and C. externa, respectively. Also, pyriproxyfen reduced the first-larval-instar period and lengthened the fourth of E. connexa. Acetamiprid was more toxic to E. connexa than to C. externa at the two highest concentrations. Conversely, at those same concentrations of pyriproxyfen, the relative toxicity to the two species was reversed. The present work represents the first investigation on the comparative susceptibility of two relevant Neotropical biological control agents to acetamiprid and pyriproxyfen. Also, it highlights the necessity of assessing long-term effects in the compatibility studies between natural enemies of agricultural pests and insecticides.Centro de Investigaciones del MedioambienteCentro de Estudios Parasitológicos y de Vectore

Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region

Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action— pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin— were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %). Malformations in adults emerged from treated pupae were observed after acetamiprid (82.7 and 100 % for 100 and 200 mg a.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin (13.3 %) treatments. A longer mean oviposition time was also observed in adults emerged from pupae treated with cypermethrin. Moreover, the latter insecticide as well as teflubenzuron did not reduce reproductive parameters, whereas females emerged from pyriproxyfen-treated pupae were not be able to lay eggs even when females showed large abdomens. Upon exposure of adults, survival was reduced to approximately 90 % by acetamiprid, but no reduction occurred with pyriproxyfen, teflubenzuron, or cypermethrin though the fecundity at fifth oviposition time of the female survivors was reduced. Pyriproxyfen decreased the hatching at all the oviposition times tested, whereas fertility was reduced in the fourth and fifth ovipositions by teflubenzuron and in the first and third ovipositions by cypermethrin. In conclusion, all four insecticides tested exhibited lethal or sublethal effects, or both, on E. connexa. The neurotoxic insecticides were more harmful than the insect-growth regulators, and pupae were more susceptible than adults. The toxicity of insecticides on the conservation of predators in agroecosystems of the Neotropical Region is discussed.Centro de Estudios Parasitológicos y de VectoresCentro de Investigaciones del Medioambient

Abnormalities in amphibian populations inhabiting agroecosystems in northeastern Buenos Aires Province, Argentina

The occurrence of abnormalities in amphibians has been reported in many populations, and its increase could be related to environmental pollution and habitat degradation. We evaluated the type and prevalence of abnormalities in 5 amphibian populations from agroecosystems with different degrees of agricultural disturbance (cultivated and reference areas). We detected 9 types of abnormalities, of which the most frequent were those occurring in limbs. The observed prevalence of abnormality in assessed populations from cultivated and reference areas was as follows: Rhinella fernandezae (37.1 and 10.2%, respectively), Leptodactylus latrans adults (28.1 and 9.2%) and juveniles (32.9 and 15.3%), and Hypsiboas pulchellus (11.6 and 2.8%). Scinax granulatus populations did not show abnormalities. Pseudis minuta, which was only detected in the reference area, exhibited a prevalence of 13.3%. For R. fernandezae, L. latrans, and H. pulchellus, generalized linear mixed models showed that prevalence of abnormalities was significantly higher (p < 0.05) in cultivated than in reference areas. L. latrans juveniles were more vulnerable to abnormalities than adults (p < 0.05). The presence of abnormalities in some species inhabiting different agroecosystems suggests that environmental stress factors might be responsible for their occurrence. While we detected pesticides (endosulfan, cypermethrin, and chlorpyrifos) and lower dissolved oxygen levels in ponds of the cultivated area, no data are currently available on how other factors, such as injuries from predators and parasite infections, vary by land use. Further research will be necessary to evaluate possible causes of abnormalities detected in the present study mainly in the context of factor interactions.Facultad de Ciencias Naturales y Muse

Edge-to-Edge Technique to Minimize Ovelapping of Multiple Bioresorbable Scaffolds Plus Drug Eluting Stents in Revascularization of Long Diffuse Left Anterior Descending Coronary Artery Disease

Background: Implantation of Drug Eluting Stents (DES) plus bioresorbable scaffolds (BVS) in very long diffuse left anterior descending coronary artery (LAD) disease may be problematic because of multiple devices overlapping. We sought to assess the short and mid-tern outcomes of combined implantation of DES and BVS using a novel "edge-to-edge" technique in patients with diffuse LAD disease. Methods: Patients with long diffuse LAD disease were enrolled in a prospective registry from 1st August 2014 to 1st August 2015 and treated with IVUS-aided percutaneous coronary intervention using a DES plus a single or multiple BVS using a novel "edge-to-edge" technique. Clinical follow up and invasive follow up driven by clinical justification was performed. Results: Twenty-three patients (5 females, mean age 59.1 +/- 9.1 years) were enrolled. Mean length of LAD disease was 73.1 +/- 20.6 mm. Mean number of DES and BVS implanted was 1.2 +/- 0.4 and 1.7 +/- 1.3, respectively. At a mean follow-up of 11.3 +/- 3.8 months, no stent thrombosis or MACE were observed. Angiographic and IVUS follow-up at a mean of 6.6 +/- 0.7 months showed no significant angiographic restenosis and no appreciable stent gaps. Conclusions: In revascularization of long diffuse disease of the LAD, the edge-to-edge implantation technique appears to be feasible resulting in no restenosis or thrombosis on the short-term follow-up

Efectos indirectos de insecticidas convencionales y biorracionales sobre la alimentación de Rachiplusia nu (Lepidoptera: Noctuidae)

La evaluación conjunta de los efectos letales y subletales de insecticidas sobre plagas, permite alcanzar un mejor conocimiento de su eficacia de acción. En este sentido, la alteración de los patrones de consumo foliar de una plaga, es un importante punto final para analizar la efectividad de insecticidas sobre insectos fitófagos. Los insecticidas que interfieren con el normal comportamiento alimentario de un insecto plaga contribuyen en el manejo de su población. El objetivo del presente estudio fue evaluar el efecto del endosulfán, cipermetrina, spinosad y metoxifenocida sobre el comportamiento alimentario de Rachiplusia nu, plaga potencial de varios cultivos, en especial soya, a través de experimentos de elección en laboratorio (Centro de Investigaciones del Medio Ambiente (CIMA) La Plata, Argentina). Además, se evaluó la supervivencia de las larvas expuestas a dichos productos. La cipermetrina y el spinosad indujeron efectos antialimentarios sobre las larvas tratadas. El endosulfán no causó efectos significativos sobre este punto final, mientras que las larvas expuestas a metoxifenocida mostraron preferencia por las hojas tratadas. Los insecticidas biorracionales ocasionaron mayor mortalidad sobre R. nu que los convencionales. Estos resultados aportan conocimientos básicos para redefinir estrategias de control.The assessment of sublethal and lethal effects of insecticides on pests allows obtaining further insight of their efficacy. In this way, the pest feeding pattern is a relevant toxicological endpoint to analyze the effectiveness of insecticides on phytophagous insects, due to insecticides that interfere with the normal feeding behavior of a pest contributing to its population management. The objective of the present study was evaluating the effects of endosulfan, cypermethrin, spinosad and methoxyfenozide on feeding pattern of Rachiplusia nu, a potential pest in several crops but mainly in soybean, using laboratory choice test (Centro de Investigaciones del Medio Ambiente (CIMA) La Plata, Argentina). Additionally, the larval survival was also assessed. Cypermethrin and spinosad induced antifeedant effects on exposed larvae. Endosulfan did not cause significant effects, while larvae exposed to methoxyfenozide showed preference towards the treated leaves. Biorational insecticides showed higher mortality to R. nu control than conventional ones. These new insights contribute with knowledge for redefining effective pest control strategies.Fil: Rimoldi, Federico. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fogel, Marilina Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); ArgentinaFil: Schneider, Marcela Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); ArgentinaFil: Ronco, Alicia Estela. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effectiveness of polymyxin B-immobilized fiber column in sepsis: a systematic review

INTRODUCTION: Severe sepsis and septic shock are common problems in the intensive care unit and carry a high mortality. Endotoxin, one of the principal components on the outer membrane of gram-negative bacteria, is considered important to their pathogenesis. Polymyxin B bound and immobilized to polystyrene fibers (PMX-F) is a medical device that aims to remove circulating endotoxin by adsorption, theoretically preventing the progression of the biological cascade of sepsis. We performed a systematic review to describe the effect in septic patients of direct hemoperfusion with PMX-F on outcomes of blood pressure, use of vasoactive drugs, oxygenation, and mortality reported in published studies. METHODS: We searched PubMed, the Cochrane Collaboration Database, and bibliographies of retrieved articles and consulted with experts to identify relevant studies. Prospective and retrospective observational studies, pre- and post-intervention design, and randomized controlled trials were included. Three authors reviewed all citations. We identified a total of 28 publications - 9 randomized controlled trials, 7 non-randomized parallel studies, and 12 pre-post design studies - that reported at least one of the specified outcome measures (pooled sample size, 1,425 patients: 978 PMX-F and 447 conventional medical therapy). RESULTS: Overall, mean arterial pressure (MAP) increased by 19 mm Hg (95% confidence interval [CI], 15 to 22 mm Hg; p < 0.001), representing a 26% mean increase in MAP (range, 14% to 42%), whereas dopamine/dobutamine dose decreased by 1.8 microg/kg per minute (95% CI, 0.4 to 3.3 microg/kg per minute; p = 0.01) after PMX-F. There was significant intertrial heterogeneity for these outcomes (p < 0.001), which became non-significant when analysis was stratified for baseline MAP. The mean arterial partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio increased by 32 units (95% CI, 23 to 41 units; p < 0.001). PMX-F therapy was associated with significantly lower mortality risk (risk ratio, 0.53; 95% CI, 0.43 to 0.65). The trials assessed had suboptimal method quality. CONCLUSION: Based on this critical review of the published literature, direct hemoperfusion with PMX-F appears to have favorable effects on MAP, dopamine use, PaO2/FiO2 ratio, and mortality. However, publication bias and lack of blinding need to be considered. These findings support the need for further rigorous study of this therapy

Protective effect of resin adsorption on septic plasma-induced tubular injury

Introduction: A pro-apoptotic effect of circulating mediators on renal tubular epithelial cells has been involved in the pathogenesis of sepsis-associated acute kidney injury (AKI). Adsorption techniques have been showed to efficiently remove inflammatory cytokines from plasma. The aim of this study was to evaluate the efficiency of the hydrophobic resin Amberchrom CG161 M to adsorb from septic plasma soluble mediators involved in tubular injury. Methods: We enrolled in the study 10 critically ill patients with sepsis-associated AKI and we evaluated the effects of their plasma on granulocyte adhesion, apoptosis and functional alterations of cultured human kidney tubular epithelial cells. We established an in vitro model of plasma adsorption and we studied the protective effect of unselective removal of soluble mediators by the Amberchrom CG161 M resin on septic plasma-induced tubular cell injury. Results: Plasma from septic patients induced granulocyte adhesion, apoptosis and altered polarity in tubular cells. Plasma adsorption significantly decreased these effects and abated the concentrations of several soluble mediators. The inhibition of granulocyte adhesion to tubular cells was associated with the down-regulation of ICAM-1 and CD40. Resin adsorption inhibited tubular cell apoptosis induced by septic plasma by down-regulating the activation of caspase-3, 8, 9 and of Fas/death receptor-mediated signalling pathways. The alteration of cell polarity, morphogenesis, protein reabsorption and the down-regulation of the tight junction molecule ZO-1, of the sodium transporter NHE3, of the glucose transporter GLUT-2 and of the endocytic receptor megalin all induced by septic plasma were significantly reduced by resin adsorption. Conclusions: Septic plasma induced a direct injury of tubular cells by favouring granulocyte adhesion, by inducing cell apoptosis and by altering cell polarity and function. All these biological effects are related to the presence of circulating inflammatory mediators that can be efficiently removed by resin adsorption with a consequent limitation of tubular cell injury

Abnormalities in amphibian populations inhabiting agroecosystems in northeastern Buenos Aires Province, Argentina

The occurrence of abnormalities in amphibians has been reported in many populations, and its increase could be related to environmental pollution and habitat degradation. We evaluated the type and prevalence of abnormalities in 5 amphibian populations from agroecosystems with different degrees of agricultural disturbance (cultivated and reference areas). We detected 9 types of abnormalities, of which the most frequent were those occurring in limbs. The observed prevalence of abnormality in assessed populations from cultivated and reference areas was as follows: Rhinella fernandezae (37.1 and 10.2%, respectively), Leptodactylus latrans adults (28.1 and 9.2%) and juveniles (32.9 and 15.3%), and Hypsiboas pulchellus (11.6 and 2.8%). Scinax granulatus populations did not show abnormalities. Pseudis minuta, which was only detected in the reference area, exhibited a prevalence of 13.3%. For R. fernandezae, L. latrans, and H. pulchellus, generalized linear mixed models showed that prevalence of abnormalities was significantly higher (p < 0.05) in cultivated than in reference areas. L. latrans juveniles were more vulnerable to abnormalities than adults (p < 0.05). The presence of abnormalities in some species inhabiting different agroecosystems suggests that environmental stress factors might be responsible for their occurrence. While we detected pesticides (endosulfan, cypermethrin, and chlorpyrifos) and lower dissolved oxygen levels in ponds of the cultivated area, no data are currently available on how other factors, such as injuries from predators and parasite infections, vary by land use. Further research will be necessary to evaluate possible causes of abnormalities detected in the present study mainly in the context of factor interactions.Facultad de Ciencias Naturales y Muse