Patricia Sosa

Uraemic toxins increase in serum parallel to a decline in the glomerular filtration rate and the development of sarcopenia in patients with chronic kidney disease (CKD). This study analyses the role of uraemic toxins in sarcopenia at different stages of CKD, evaluating changes in the muscular regeneration process. Cultured C2C12 cells were incubated with a combination of indoxyl sulphate and p-cresol at high doses (100 µg/mL) or low doses (25 µg/mL and 10 µg/mL) resembling late or early CKD stages, respectively. Cell proliferation (analysed by scratch assays and flow cytometry) was inhibited only by high doses of uraemic toxins, which inactivated the cdc2-cyclin B complex, inhibiting mitosis and inducing apoptosis (analysed by annexin V staining). By contrast, low doses of uraemic toxins did not affect proliferation, but reduced myogenic differentiation, primed with 2% horse serum, by inhibiting myogenin expression and promoting fibro-adipogenic differentiation. Finally, to assess t...

Hyperphosphatemia has been related to the development of sarcopenia in aging mice. We describe the intracellular mechanisms involved in the impairment of the myogenic differentiation promoted by hyperphosphatemia and analyse these mechanisms in the muscle from older mice.

Endothelial dysfunction, with increased endothelin-1 (ET-1) synthesis, and sarcopenia, characterized by the loss of muscular mass and strength, are two aging–related conditions. However, a relationship between them has not been already established. The aim of this study was to determine whether ET-1 induces senescence and fibrosis in cultured murine myoblasts, which could be involved in the development of sarcopenia related to aging. For this purpose, myoblasts were incubated with ET-1 to assess cellular senescence, analyzed by senescence associated β-galactosidase activity and p16 expression; and fibrosis, assessed by fibronectin expression. ET-1 induced myoblast senescence and fibrosis through ETA receptor. The use of antioxidants and several antagonists revealed that ET-1 effect on senescence and fibrosis depended on ROS production and activation of PI3K-AKT-GSK pathway. To stress the in vivo relevance of these results, circulating ET-1, muscular strength, muscular fibrosis and p16 expression were measured in male C57Bl6 mice from 5-18-24-months-old. Old mice shown high levels of ET-1 correlated with muscular fibrosis, muscular p16 expression and loss of muscle strength. In conclusion, ET-1 promotes fibrosis and senescence in cultured myoblasts, similar results were found in old mice, suggesting a potential role for ET-1 in the development of sarcopenia related to aging.

Introduccion. La epilepsia es una enfermedad cronica que afecta al 0,5-1% de la poblacion, mayormente de inicio durante la infancia. Un tercio de los pacientes evoluciona hacia una forma refractaria al tratamiento con farmacos antiepilepticos, lo que plantea al equipo de salud un desafio terapeutico. La dieta cetogenica (DC) es un tratamiento no farmacologico efectivo utilizado como un metodo alternativo para el tratamiento de la epilepsia refractaria. Objetivos. Es necesario establecer directrices para utilizar la DC adecuadamente y asi expandir su conocimiento y utilizacion en paises hispanoparlantes. El Comite Nacional de Dieta Cetogenica, dependiente de la Sociedad Argentina de Neurologia Infantil, elaboro este consenso para estandarizar el uso de la DC basandose en la bibliografia publicada y la experiencia clinica. El grupo esta formado por neuropediatras, medicos nutricionistas y licenciadas en nutricion de cinco provincias de Argentina pertenecientes a 10 centros que aplican la DC como tratamiento de la epilepsia refractaria. Desarrollo. Se exponen temas tales como la seleccion del paciente, el asesoramiento a la familia antes del tratamiento, las interacciones de la DC con la medicacion anticonvulsionante, los suplementos, el control de efectos adversos y la retirada de dicha dieta. Conclusiones. La DC es un tratamiento util para los pacientes pediatricos con epilepsia intratable. Es fundamental la educacion y colaboracion del paciente y la familia. El tratamiento debe llevarlo a cabo un equipo interdisciplinar experimentado, siguiendo un protocolo. La formacion de un grupo nacional interdisciplinar, y la publicacion de este consenso, ofrece la posibilidad de orientar a nuevos centros en su implantacion.

Introduccion. La epilepsia es una enfermedad cronica que afecta al 0,5-1% de la poblacion, y un tercio de los pacientes evoluciona hacia una forma refractaria a los farmacos antiepilepticos. Dentro de los tratamientos no farmacologicos disponibles, la dieta cetogenica Atkins modificada es un tratamiento efectivo utilizado desde 2003 como otra alternativa en ninos y adultos con epilepsia refractaria. Desarrollo. El Comite Nacional de Dieta Cetogenica, dependiente de la Sociedad Argentina de Neurologia Infantil, elaboro este consenso sobre dieta Atkins modificada basandose en una revision de la bibliografia y en su experiencia clinica. Este consenso explica los distintos aspectos que hay que tener en cuenta sobre la dieta Atkins modificada, eleccion de pacientes, forma de implementacion, diversos controles y efectos adversos. A diferencia de la dieta cetogenica clasica, se inicia sin ayuno ni hospitalizacion, y no hay restriccion proteica, calorica o hidrica, por lo que mejora la palatabilidad y, consecuentemente, la tolerabilidad. Conclusiones. La dieta Atkins modificada es un tratamiento util para pacientes con epilepsia intratable. La publicacion de este consenso ofrece la posibilidad de orientar a nuevos centros en su implementacion.

In chronic kidney disease (CKD), increases in serum phosphate and parathyroid hormone (PTH) aggravate vascular calcification (VC) and bone loss. This study was designed to discriminate high phosphorus (HP) and PTH contribution to VC and bone loss. Nephrectomized rats fed a HP diet underwent either sham operation or parathyroidectomy and PTH 1-34 supplementation to normalize serum PTH. In uraemic rats fed a HP diet, parathyroidectomy with serum PTH 1-34 supplementation resulted in (i) reduced aortic calcium (80%) by attenuating osteogenic differentiation (higher α-actin; reduced Runx2 and BMP2) and increasing the Wnt inhibitor Sclerostin, despite a similar degree of hyperphosphataemia, renal damage and serum Klotho; (ii) prevention of bone loss mostly by attenuating bone resorption and increases in Wnt inhibitors; and (iii) a 70% decrease in serum calcitriol levels despite significantly reduced serum Fgf23, calcium and renal 24-hydroxylase, which questions that Fgf23 is the main regu...

In mammalians, advancing age is associated with sarcopenia, the progressive and involuntary loss of muscle mass and strength. Hyperphosphatemia is an aging-related condition involved in several pathologies. The aim of this work was to assess whether hyperphosphatemia plays a role in the age-related loss of mass muscle and strength by inducing cellular senescence in murine myoblasts and to explore the intracellular mechanism involved in this effect. Cultured mouse CC cells were treated with 10 mM beta-glycerophosphate (BGP] at different periods of time to induce hyperphosphatemia. BGP promoted cellular senescence after 24 h of treatment, assessed by the increased expression of p53, acetylated-p53 and p21 and senescence associated β-galactosidase activity. In parallel, BGP increased ILK expression and activity, followed by mTOR activation and autophagy reduction. Knocking-down ILK expression increased autophagy and protected cells from senescence induced by hyperphosphatemia. BGP also...

During the last twenty years Eosinophilic Esophagitis has become one the most important causes of esophageal disfunction in children, food impactation in adolescents and young adults, therapeutic failure in patients with gastroesophageal reflux disease (GERD) and the most frecuent eosinophilic disease of the gastrointestinal tract. We present recommendations for the diagnosis and treatment of the disease based in a systematic review of the literature.

Epilepsy is a chronic disease that affects 0.5-1% of the population. One third of the patients become refractory to antiepileptic drugs. Among the non-pharmacological treatments available, the modified Atkins diet is an effective treatment used since 2003 as another alternative for children and adults with refractory epilepsy. The Ketogenic Diet National Committee, which depends on the Argentine Society of Pediatric Neurology, elaborated this consensus on the modified Atkins diet, basing itself on a review of the literature and on their clinical experience. This consensus in Spanish explains the different aspects to be taken into account regarding the modified Atkins diet, patient selection, implementation, different controls and adverse effects. Unlike the classic ketogenic diet, the modified Atkins diet is initiated without fasting or hospital stay, nor does it require protein, calorie or fluid restriction, thus improving patient palatability and consequently patient tolerability....

Cellular senescence can be prematurely induced by oxidative stress involved in aging. In this work, we were searching for novel intermediaries in oxidative stress-induced senescence, focusing our interest on integrin-linked kinase (ILK), a scaffold protein at cell-extracellular matrix (ECM) adhesion sites, and on theKlothogene. Cultured renal cells were treated with glucose oxidase (GOx) for long time periods. GOx induced senescence, increasing senescence associatedβ-galactosidase activity and the expression of p16. In parallel, GOx increased ILK protein expression and activity. Ectopic overexpression of ILK in cells increased p16 expression, even in the absence of GOx, whereas downregulation of ILK inhibited the increase in p16 due to oxidative stress. Additionally, GOx reducedKlothogene expression and cells overexpressing Klotho protein did not undergo senescence after GOx addition. We demonstrated a direct link between ILK andKlothosince silencing ILK expression in cells and mice...