330 research outputs found
Exploring the ontogenetic scaling hypothesis during the diversification of pollination syndromes in <i>Caiophora</i> (Loasaceae, subfam. Loasoideae)
Phenotypic diversification of flowers is frequently attributed to selection by different functional groups of pollinators. During optimization of floral phenotype, developmental robustness to genetic and non-genetic perturbations is expected to limit the phenotypic space available for future evolutionary changes. Although adaptive divergence can occur without altering the basic developmental programme of the flower (ontogenetic scaling hypothesis), the rarity of reversion to ancestral states following adaptive radiations of pollination syndromes suggests that changes in the ancestral developmental programme of the flower are common during such evolutionary transitions. Evidence suggests that flower diversification into different pollination syndromes in the Loasoideae genus Caiophora took place during a recent adaptive radiation in the central Andes. This involved transitions from bee to hummingbird and small rodent pollination. The aim of this work was to examine if the adaptive radiation of pollination syndromes in Caiophora occurred through ontogenetic scaling or involved a departure from the ontogenetic pattern basal to this genus.Fil: Strelin, Marina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Fornoni, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional Autónoma de México; MéxicoFil: Klingenberg, Christian Peter. University of Manchester; Reino UnidoFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin
engineering human renal epithelial cells for transplantation in regenerative medicine
Abstract Cellular transplantation may treat several human diseases by replacing damaged cells and/or providing a local source of trophic factors promoting regeneration. We utilized human renal epithelial cells (hRECs) isolated from cadaveric donors as a cell model. For efficacious implementation of hRECs for treatment of kidney diseases, we evaluated a novel encapsulation strategy for immunoisolation of hRECs and lentiviral transduction of the Green Fluorescent Protein (GFP) as model gene for genetic engineering of hRECs to secrete desired trophic factors. In specific, we determined whether encapsulation through conformal coating and/or GFP transduction of hRECs allowed preservation of cell viability and of their trophic factor secretion. To that end, we optimized cultures of hRECs and showed that aggregation in three-dimensional spheroids significantly preserved cell viability, proliferation, and trophic factor secretion. We also showed that both wild type and GFP-engineered hRECs could be efficiently encapsulated within conformal hydrogel coatings through our fluid dynamic platform and that this resulted in further improvement of cell viability and trophic factors secretion. Our findings may lay the groundwork for future therapeutics based on transplantation of genetically engineered human primary cells for treatment of diseases affecting kidneys and potentially other tissues
Local dispersal pathways during the invasion of the cactus moth, Cactoblastis cactorum, within North America and the Caribbean
Cactoblastis cactorum, a species of moth native to Argentina, feeds on several prickly pear cactus species (Opuntia) and has been successfully used as a biological control of invading Opuntia species in Australia, South Africa and native ruderal Opuntia species in some Caribbean islands. Since its introduction to the Caribbean its spread was uncontrolled, invading successfully Florida, Texas and Louisiana. Despite this long history of invasion, we are still far from understanding the factors determining the patterns of invasion of Cactoblastis in North America. Here, we explored three non-mutually exclusive explanations: a) a stepping stone model of colonization, b) long distance colonization due to hurricanes, and/or c) hitchhiking through previously reported commercial routes. Genetic diversity, genetic structure and the patterns of migration among populations were obtained by analyzing 10 nuclear microsatellite loci. Results revealed the presence of genetic structure among populations of C. cactorum in the invaded region and suggest that both marine commercial trade between the Caribbean islands and continental USA, as well as recurrent transport by hurricanes, explain the observed patterns of colonization. Provided that sanitary regulations avoiding humanmediated dispersal are enforced, hurricanes probably represent the most important agent of dispersal and future invasion to continental areas.Fil: Andraca Gómez, Guadalupe. Universidad Nacional Autónoma de México. Instituto de Ecología; MéxicoFil: Lombaert, Eric. Université Côte d'Azur; Francia. Centre National de la Recherche Scientifique; FranciaFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Pérez Ishiwara, Rubén. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Boege, Karina. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Domínguez, César A.. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; MéxicoFil: Fornoni, Juan. Universidad Nacional Autonoma de Mexico. Departamento de Ecología Evolutiva; Méxic
Interspecific variation and elevated CO2 influence the relationship between plant chemical resistance and regrowth tolerance
To understand how comprehensive plant defense phenotypes will respond to global change, we investigated the legacy effects of elevated CO2 on the relationships between chemical resistance (constitutive and induced via mechanical damage) and regrowth tolerance in four milkweed species (Asclepias). We quantified potential resistance and tolerance trade‐offs at the physiological level following simulated mowing, which are relevant to milkweed ecology and conservation. We examined the legacy effects of elevated CO2 on four hypothesized trade‐offs between the following: (a) plant growth rate and constitutive chemical resistance (foliar cardenolide concentrations), (b) plant growth rate and mechanically induced chemical resistance, (c) constitutive resistance and regrowth tolerance, and (d) regrowth tolerance and mechanically induced resistance. We observed support for one trade‐off between plant regrowth tolerance and mechanically induced resistance traits that was, surprisingly, independent of CO2 exposure. Across milkweed species, mechanically induced resistance increased by 28% in those plants previously exposed to elevated CO2. In contrast, constitutive resistance and the diversity of mechanically induced chemical resistance traits declined in response to elevated CO2 in two out of four milkweed species. Finally, previous exposure to elevated CO2 uncoupled the positive relationship between plant growth rate and regrowth tolerance following damage. Our data highlight the complex and dynamic nature of plant defense phenotypes under environmental change and question the generality of physiologically based defense trade‐offs.To understand how comprehensive plant defense phenotypes will respond to global change, we investigated the legacy effects of elevated CO2 on the relationships between chemical resistance and regrowth tolerance in four milkweed species (Asclepias). We found interspecific variation among milkweed species influenced the relationship between mechanically induced chemical resistance and regrowth tolerance. Previous exposure to elevated CO2 increased mechanically induced resistance by 28% and uncoupled the positive relationship between plant growth rate and regrowth tolerance following damage.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155974/1/ece36284_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155974/2/ece36284.pd
Effects of anther‐stigma position on cross‐pollination efficiency in a hermaphroditic plant
Fil: Baranzelli, Matias C. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Baranzelli, Matias C. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Baranzelli, Matias C. Consejo Nacional de Investigaciones, Científicas y Técnicas; Argentina.Fil: Ochoa‐Sánchez, Manuel. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Ramos, Sergio E. University of Zurich. Department of Geography and Department of
Chemistry, Zurich; Switzerland.Fil: Baena‐Díaz, Fernanda. Instituto de Ecología A.C. Red de Ecoetología, Xalapa; México.Fil: Sosenski, Paula. Universidad Autónoma de Yucatán, Mérida, Yucatán; México.Fil: Sosenski, Paula. Consejo Nacional de Humanidades, Ciencias y Tecnologías; México.Fil: Domínguez, Cesar A. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Fornoni, Juan. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Abstract: Premise: Evolution of cross‐pollination efficiency depends on the genetic variation of flower traits, the pollen vector, and flower trait matching between pollen donors and recipients. Trait matching has been almost unexplored among nonheterostylous species, and we examined whether the match of anther length in pollen donors and stigma length in pollen recipients influences the efficiency of cross‐pollination. To
explore potential constraints for evolutionary response, we also quantified genetic variation and covariation among sepal length, petal length and width, stamen length, style length, and herkogamy.
Methods: We created 58 experimental arrays of Turnera velutina that varied in the extent of mismatch in the position of anthers and stigmas between single‐flowered plants. Genetic variation and correlations among flower traits were estimated under greenhouse conditions.
Results: Style length, but not herkogamy, influenced the efficiency of cross‐pollination. Plants with stamen length that matched the style length of other plants were more efficient pollen donors, whereas those with the style protruding above the stamens of other plants were more efficient pollen recipients. Significant broad‐sense heritability (0.22 > hB2 r < 0.85)
among floral traits were detected.
Conclusions: Our results demonstrated that anther‐stigma mismatch between flowers
contributed to variation in the efficiency of cross‐pollination. The genetic correlations
between stamen length and other floral traits suggests that any change in cross‐pollination efficiency would be driven by changes in style rather than in stamen length.info:eu-repo/semantics/publishedVersionFil: Baranzelli, Matias C. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Baranzelli, Matias C. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal. Laboratorio de Ecología Evolutiva y Biología Floral; Argentina.Fil: Baranzelli, Matias C. Consejo Nacional de Investigaciones, Científicas y Técnicas; Argentina.Fil: Ochoa‐Sánchez, Manuel. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Ramos, Sergio E. University of Zurich. Department of Geography and Department of
Chemistry, Zurich; Switzerland.Fil: Baena‐Díaz, Fernanda. Instituto de Ecología A.C. Red de Ecoetología, Xalapa; México.Fil: Sosenski, Paula. Universidad Autónoma de Yucatán, Mérida, Yucatán; México.Fil: Sosenski, Paula. Consejo Nacional de Humanidades, Ciencias y Tecnologías; México.Fil: Domínguez, Cesar A. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México.Fil: Fornoni, Juan. Universidad Nacional Autónoma de México. Instituto de Ecología, Ciudad de México; México
Rituximab in Children with Steroid-Dependent Nephrotic Syndrome: A Multicenter, Open-Label, Noninferiority, Randomized Controlled Trial.
Steroid-dependent nephrotic syndrome (SDNS) carries a high risk of toxicity from steroids or steroid-sparing agents. This open-label, noninferiority, randomized controlled trial at four sites in Italy tested whether rituximab is noninferior to steroids in maintaining remission in juvenile SDNS. We enrolled children age 1-16 years who had developed SDNS in the previous 6-12 months and were maintained in remission with high prednisone doses ( 650.7 mg/kg per day). We randomly assigned participants to continue prednisone alone for 1 month (control) or to add a single intravenous infusion of rituximab (375 mg/m(2); intervention). Prednisone was tapered in both groups after 1 month. For noninferiority, rituximab had to permit steroid withdrawal and maintain 3-month proteinuria (mg/m(2) per day) within a prespecified noninferiority margin of three times the levels among controls (primary outcome). We followed participants for 651 year to compare risk of relapse (secondary outcome). Fifteen children per group (21 boys; mean age, 7 years [range, 2.6-13.5 years]) were enrolled and followed for 6460 months (median, 22 months). Three-month proteinuria was 42% lower in the rituximab group (geometric mean ratio, 0.58; 95% confidence interval, 0.18 to 1.95 [i.e., within the noninferiority margin of three times the levels in controls]). All but one child in the control group relapsed within 6 months; median time to relapse in the rituximab group was 18 months (95% confidence interval, 9 to 32 months). In the rituximab group, nausea and skin rash during infusion were common; transient acute arthritis occurred in one child. In conclusion, rituximab was noninferior to steroids for the treatment of juvenile SDNS
Red wine polyphenols prevent metabolic and cardiovascular alterations associated with obesity in Zucker fatty rats (Fa/Fa)
Peer reviewedPublisher PD
Nephrin Is Expressed on the Surface of Insulin Vesicles and Facilitates Glucose-Stimulated Insulin Release
Nephrin, an immunoglobulin-like protein essential for the function of the glomerular podocyte and regulated in diabetic nephropathy, is also expressed in pancreatic beta-cells, where its function remains unknown. The aim of this study was to investigate whether diabetes modulates nephrin expression in human pancreatic islets and to explore the role of nephrin in beta-cell function.
Nephrin expression in human pancreas and in MIN6 insulinoma cells was studied by Western blot, PCR, confocal microscopy, subcellular fractionation, and immunogold labeling. Islets from diabetic (n = 5) and nondiabetic (n = 7) patients were compared. Stable transfection and siRNA knockdown in MIN-6 cells/human islets were used to study nephrin function in vitro and in vivo after transplantation in diabetic immunodeficient mice. Live imaging of green fluorescent protein (GFP)-nephrin-transfected cells was used to study nephrin endocytosis.
Nephrin was found at the plasma membrane and on insulin vesicles. Nephrin expression was decreased in islets from diabetic patients when compared with nondiabetic control subjects. Nephrin transfection in MIN-6 cells/pseudoislets resulted in higher glucose-stimulated insulin release in vitro and in vivo after transplantation into immunodeficient diabetic mice. Nephrin gene silencing abolished stimulated insulin release. Confocal imaging of GFP-nephrin-transfected cells revealed nephrin endocytosis upon glucose stimulation. Actin stabilization prevented nephrin trafficking as well as nephrin-positive effect on insulin release.
Our data suggest that nephrin is an active component of insulin vesicle machinery that may affect vesicle-actin interaction and mobilization to the plasma membrane. Development of drugs targeting nephrin may represent a novel approach to treat diabetes
Issues in solid-organ transplantation in children: translational research from bench to bedside
In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children
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Outcomes of critically ill solid organ transplant patients with COVID‐19 in the United States
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163464/2/ajt16280.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163464/1/ajt16280_am.pd
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