49 research outputs found

    Efecto de distintos eventos biotecnol√≥gicos de ma√≠z en el consumo y mortalidad de la ‚Äúoruga cortadora √°spera‚ÄĚ (Agrotis robusta)

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    Agrotis robusta is a species of moth belonging to the complex of cutworms that cause damage in summer crops in the Regi√≥n Semi√°rida Pampeana. A tool used to control Lepidoptera are the "Bt corn", transgenic crops that incorporate insecticidal proteins from the bacterium Bacillus thuringiensis. The objective of this work was to determine the effect produced by different biotechnological events of corn on the consumption of leaf area, weight and mortality of Agrotis robusta larvae. For this, larvae were fed for 10 days with foliar tissue from five hybrids of "Bt corn": Herculex(HX), Maizgard(MG), Powercore(PW), Agrisure Viptera3(VIP3), VT Triple Pro(VT3P), corn without transgenic events for insect resistance (NBT) and a blank treatment with wild quinoa (Q). An experimental design in random blocks with three repetitions was arranged. The weight of the larvae, consumption and mortality was evaluated. The PW, VT3P and VIP3 corn hybrids, which incorporate more than one Bt toxin, produce a decrease in leaf area consumption and weight loss in A. robusta larvae. The highest mortality is observed in the PW treatment, followed by VT3P and VIP3. The hybrids MG and HX record a consumption of leaf area, weight and mortality of larvae similar to the NBT treatmentAgrotis robusta es una especie perteneciente al complejo de orugas cortadoras que provocan da√Īos en cultivos de la Regi√≥n Semi√°rida Pampeana. Una herramienta utilizada para el control de lepid√≥pteros son los ‚Äúma√≠ces Bt‚ÄĚ, cultivos transg√©nicos que incorporan prote√≠nas insecticidas de laba cteria Bacillus thuringiensis. El objetivo fue determinar el efecto de distintos eventos biotecnol√≥gicos de ma√≠z sobre el consumo de √°rea foliar, peso y mortandad de larvas de Agrotis robusta. Para ello se alimentaron larvas durante 10 d√≠as con tejido foliar procedente de cinco h√≠bridos de ‚Äúma√≠z Bt‚ÄĚ: Herculex(HX), Maizgard(MG), Powercore(PW), Agrisure Viptera3(VIP3), VT Triple Pro(VT3P), un ma√≠z sin eventos transg√©nicos para resistencia a insectos (NBT) y un tratamiento blanco con quinoa silvestre (Q). Se dispuso un dise√Īo experimental en bloques al azar con tres repeticiones. Se evalu√≥ el peso de larvas, consumo y mortandad. Los h√≠bridos de ma√≠z PW, VT3P y VIP3, que incorporan m√°s de una toxina Bt, producen disminuci√≥n del consumo de √°rea foliar y p√©rdidas de peso en larvas de A. robusta. La mayor mortandad se observa en el tratamiento PW, seguido por VT3P y VIP3. Los h√≠bridos MG y HX registran un consumo de √°rea foliar, peso y mortandad de larvas similar al tratamiento NBT

    Multivariate analysis of brain metabolism reveals chemotherapy effects on prefrontal cerebellar system when related to dorsal attention network

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    BACKGROUND: Functional brain changes induced by chemotherapy are still not well characterized. We used a novel approach with a multivariate technique to analyze brain resting state [(18)‚ÄČF]FDG-PET in patients with lymphoma, to explore differences on cerebral metabolic glucose rate between chemotherapy-treated and non-treated patients. METHODS: PET/CT scan was performed on 28 patients, with 14 treated with systemic chemotherapy. We used a support vector machine (SVM) classification, extracting the mean metabolism from the metabolic patterns, or networks, that discriminate the two groups. We calculated the correct classifications of the two groups using the mean metabolic values extracted by the networks. RESULTS: The SVM classification analysis gave clear-cut patterns that discriminate the two groups. The first, hypometabolic network in chemotherapy patients, included mostly prefrontal cortex and cerebellar areas (central executive network, CEN, and salience network, SN); the second, which is equal between groups, included mostly parietal areas and the frontal eye field (dorsal attention network, DAN). The correct classification membership to chemotherapy or not chemotherapy-treated patients, using only one network, was of 50% to 68%; however, when all the networks were used together, it reached 80%. CONCLUSIONS: The evidenced networks were related to attention and executive functions, with CEN and SN more specialized in shifting, inhibition and monitoring, DAN in orienting attention. Only using DAN as a reference point, indicating the global frontal functioning before chemotherapy, we could better classify the subjects. The emerging concept consists in the importance of the investigation of brain intrinsic networks and their relations in chemotherapy cognitive induced changes

    Chemotherapy effects on brain glucose metabolism at rest

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    Background: A growing number of studies reports that chemotherapy may impair brain functions inducing cognitive changes which can persist in a subset of cancer survivors. Aims: To investigate the neural basis of the chemotherapy-induced neurobehavioral changes by means of metabolic imaging and voxel-based statistical parametric mapping analyses. Methods: We studied the resting brain [18]FDG-PET/CT images of 43 adult cancer patients with solid (n=12, 28%) or hematologic malignancies (n=31, 72%); 12 patients were studied prior to chemotherapy (No chemotherapy) while treated patients were divided into two matched subgroups: Early High (6 chemotherapy cycles, n=10), and Late Low (>9 months after chemotherapy, <6 chemotherapy cycles, n=21). Findings: Compared to No chemotherapy, the Early High subgroup showed a significant bilateral (p<0.05) lower regional cerebral metabolic rate of glucose metabolism in both the prefrontal cortices and white matter, cerebellum, posterior medial cortices and limbic regions. A similar pattern emerged in the Early High versus Low Late comparison, while no significant result was obtained in the Low Late versus No chemotherapy comparison. The number of cycles and the post-chemotherapy time were negatively and positively correlated, respectively, with a set of these same brain regions. Interpretation: The present study shows that chemotherapy induces significant transient changes in the glucose metabolism of multiple cerebral cortical and white matter regions with a prevailing involvement of the prefrontal cortex. The severity of these changes are significantly related with the number of chemotherapy cycles and a subset of brain regions seems to present longer lasting, but more subtle, metabolic changes