46 research outputs found
¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales?
Forest plantations with different trees and purposes were traditionally developed with seminal seedlings. Actually, the most important planted tree species can be propagated by vegetative methods, so clonal silviculture has high possibilities to grow. Salicaceae plantations are established by cuttings of genetically improved trees. This determines that poplars and willows are produced under clonal silviculture systems. Furthermore, at the region of Paraná River Delta, stands are monoclonal and Populus deltoides ‘Australiano 129/60’ is the most widespread clone. These forest systems are unstable and there is a productive risk associated to emergence of pests, diseases and extreme climatic conditions. Thus, monoclonal silviculture model has some ecological and productive disadvantages. Reducing genetic diversity could threat the aims of the forest plantations and it is important to consider aspects related to biodiversity when plantations are planned. Clone combination in the same stand can be useful to increase genetic diversity, because tree species are highly diverse at both inter and intraspecific level. Mixed clonal plantations can favor to decrease the impact of productive activities on the environment, spatially distribute soil nutrient demand, increase genetic diversity and enhance stand yields.The aim of this review is to analyze previous experiences in clonal silviculture and plantation in mixed stands as a framework to propose silvicultural alternatives for Salicaceae production in Paraná River Delta, Argentina.Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ‘Australiano 129/60’ es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná
¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales? Posibles alternativas silviculturales para las Salicáceas, a partir de la revisión de experiencias previas
Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ?Australiano 129/60? es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná.Forest plantations with different trees and purposes were traditionally developed with seminal seedlings. Actually, the most important planted tree species can be propagated by vegetative methods, so clonal silviculture has high possibilities to grow. Salicaceae plantations are established by cuttings of genetically improved trees. This determines that poplars and willows are produced under clonal silviculture systems. Furthermore, at the region of Paraná River Delta, stands are monoclonal and Populus deltoides ‘Australiano 129/60’ is the most widespread clone. These forest systems are unstable and there is a productive risk associated to emergence of pests, diseases and extreme climatic conditions. Thus, monoclonal silviculture model has some ecological and productive disadvantages. Reducing genetic diversity could threat the aims of the forest plantations and it is important to consider aspects related to biodiversity when plantations are planned. Clone combination in the same stand can be useful to increase genetic diversity, because tree species are highly diverse at both inter and intraspecific level. Mixed clonal plantations can favor to decrease the impact of productive activities on the environment, spatially distribute soil nutrient demand, increase genetic diversity and enhance stand yields.The aim of this review is to analyze previous experiences in clonal silviculture and plantation in mixed stands as a framework to propose silvicultural alternatives for Salicaceae production in Paraná River Delta, Argentina.Fil: Bonnin, Sebastián Martin. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faustino, Laura I.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Alvarez, Javier A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Graciano, Corina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; Argentin
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
¿La combinación de clones posee alguna ventaja sobre los sistemas monoclonales?
Las plantaciones forestales han sido tradicionalmente desarrolladas a partir de material de propagación de origen seminal. Sin embargo, las principales especies plantadas en el mundo se pueden propagar vegetativamente, por lo que las posibilidades para el desarrollo de la silvicultura clonal son crecientes. El cultivo de Salicáceas se realiza con estacas o guías, por lo que las plantaciones son 100% producidas bajo un esquema de silvicultura clonal. Además, en el Delta del Río Paraná los rodales se instalan como bloques monoclonales y el clon Populus deltoides ‘Australiano 129/60’ es el más difundido, definiendo una matriz productiva con una estrecha diversidad genética. Esto determina que el sistema sea menos estable y trae aparejado un riesgo productivo ante la aparición de condiciones de estrés biótico o abiótico. En consecuencia, el modelo de silvicultura monoclonal presenta algunas desventajas no solo desde el punto de vista ecológico, sino también productivo. A partir de la posibilidad que brindan las especies forestales, que presentan una gran variabilidad tanto intra como interespecífica, es posible pensar en combinación de clones para aumentar la diversidad genética de las plantaciones. Las plantaciones clonales mixtas pueden favorecer a la disminución de los impactos de las actividades productivas en el ambiente, distribuir espacialmente la demanda de nutrientes del suelo, aumentar la diversidad genética y mejorar los índices de rendimiento del rodal. El objetivo de esta revisión es analizar los antecedentes de silvicultura clonal y plantaciones mixtas como base para la propuesta de alternativas silviculturales para las Salicáceas del Delta del Paraná
Endoplasmic reticulum stress in the proapoptotic action of edelfosine in solid tumor cells
The endoplasmic reticulum (ER) has been posited as a potential anticancer target. The synthetic antitumor alkyl-lysophospholipid analogue edelfosine accumulates in the ER of solid tumor cells. This ER accumulation of the drug leads to the inhibition of phosphatidylcholine and protein synthesis, G 2-M arrest, depletion of ER-stored Ca2+, Bax up-regulation and activation, transcriptional factor growth arrest and DNA damage-inducible gene 153 up-regulation, caspase-4 and caspase-8 activation, and eventually to apoptosis. Edelfosine prompted ER stress apoptotic signaling, but not the survival unfolded protein response. Edelfosine also induced persistent c-Jun NH2-terminal kinase (JNK) activation. Gene transfer-mediated overexpression of apoptosis signal-regulating kinase 1, which plays a crucial role in ER stress, enhanced edelfosine-induced JNK activation and apoptosis. Inhibition of JNK, caspase-4, or caspase-8 activation diminished edelfosine-induced apoptosis. Edelfosine treatment led to the generation of the p20 caspase-8 cleavage fragment of BAP31, directing proapoptotic signals between the ER and the mitochondria. bax-/-bak-/- double-knockout cells fail to undergo edelfosine-induced ER-stored Ca2+ release and apoptosis. Wild-type and bax-/-bak-/- cells showed similar patterns of phosphatidylcholine and protein synthesis inhibition, despite their differences in drug sensitivity. Thus, edelfosine-induced apoptosis is dependent on Bax/Bak-mediated ER-stored Ca2+ release, but phosphatidylcholine and protein synthesis inhibition is not critical. Transfection-enforced expression of Bcl-XL, which localizes specifically in mitochondria, prevented apoptosis without inhibiting ER-stored Ca2+ release. These data reveal that edelfosine induces an ER stress response in solid tumor cells, providing novel insights into the edelfosine-mediated antitumor activity. Our data also indicate that mitochondria are indispensable for this edelfosine-induced cell death initiated by ER stress. ©2007 American Association for Cancer Research.Grant support: Fondo de Investigación Sanitaria and European Commission (FISFEDER 06/0813, 04/0843, 04/0789, 03/0975, 02/1199), Ministerio de Educación y Ciencia (SAF2005-04293, BFU2005-05464), Fundación de Investigación Médica Mutua Madrileña, Fundación ‘‘la Caixa’’ (BM05-30-0), and Junta de Castilla y León (CSI04A05). T. Nieto-Miguel is the recipient of a predoctoral fellowship from the Junta de Castilla y León, L. Vay is the recipient of a predoctoral fellowship from the Fondo de Investigación Sanitaria, and C. Gajate is supported by the Ramón y Cajal Program from the Ministerio de Educación y Ciencia of Spain.Peer Reviewe
Endoplasmic Reticulum Stress in the Proapoptotic Action of Edelfosine in Solid Tumor Cells
Fertilization with urea, ammonium and nitrate produce different effects on growth, hydraulic traits and drought tolerance in Pinus taeda
Safety assessment of new nanodiamonds@corrole hybrids addressed by the response of RAW-264.7 macrophages
Safety assessment of carbon nanomaterials is of paramount importance since they are on the frontline for applications in sensing, bioimaging and drug delivery. The biocompatibility and safety of functionalized nanodiamonds (NDs) are here addressed through the study of the pro-inflammatory response of RAW-264.7 macrophages exposed to new nanodiamonds@corrole hybrids. The corrole unit selected is as a prototype for a hydrophobic organic molecule that can function as a NIR fluorophore reporter, an optical sensor, a photodynamic therapy agent or a photocatalyst. The new functional nanohybrids containing detonated nanodiamonds (NDs) were obtained through esterification using carboxylated NDs and glycol corroles. The success of the covalent functionalization via carbodiimide activation was confirmed through X-ray photoelectron spectroscopy (XPS), Raman and Fourier transform infrared (FTIR) spectroscopy. The UV-vis absorption and emission spectra of the hybrids are additive with respect to the corrole features. The cellular uptake, localization, cell viability and effects on immune cell activation of the new hybrids and of the precursors were carefully investigated using RAW-264.7 macrophages. Overall results showed that the ND@corrole hybrids had no pro-inflammatory effects on the RAW-264.7 macrophage cell line, making them an ideal candidate for a wide range of biomedical applications.publishe