Browsing by Author "Olmos, Pablo R."
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- ItemA new physiopathological classification of diabetic neuropathy(SOC MEDICA SANTIAGO, 2012) Olmos, Pablo R.; Niklitschek, Sergio; Olmos, Roberto I.; Faundez, Jorge I.; Quezada, Thomas A.; Bozinovic, Milan A.; Niklitscheka, Ian A.; Acosta, Jorge; Valencia, Claudio N.; Bravo, Felipe A.Nowadays, Diabetic Neuropathy (DN) is considered the most common cause of peripheral neuropathy in clinical practice. It can affect sensitive, motor or autonomic nerve fibers, with symmetric, asymmetric, acute or chronic presentations. Due to this variability, with multiple physiopathologic mechanisms involved, a complex clinical classification has been used until recently. The aim of this review is to present a new classification of diabetic neuropathy, based on its physiopathology. It is divided in metabolic microvascular and hypoxic, autoimmune and inflammatory, compressive, secondary to complications of diabetes and related to treatment. It must be understood that DN is not just a functional disease, but a complication of diabetes with molecular and pathological substrates caused by hyperglycemia. Therefore, normalization of blood glucose is a fundamental step towards the successful prevention and treatment of DN. (Rev Med Chile 2012; 140: 1593-1605).
- ItemDifferences in lung glutathione metabolism may account for rodent susceptibility in elastase-induced emphysema development(AMER PHYSIOLOGICAL SOC, 2009) Borzone, Gisella R.; Liberona, Leonel F.; Bustamante, Andrea P.; Saez, Claudia G.; Olmos, Pablo R.; Vecchiola, Andrea; Villagran, Andrea; Serrano, Carolina; Reyes, Tatiana P.Borzone GR, Liberona LF, Bustamante AP, Saez CG, Olmos PR, Vecchiola A, Villagran A, Serrano C, Reyes TP. Differences in lung glutathione metabolism may account for rodent susceptibility in elastase-induced emphysema development. Am J Physiol Regul Integr Comp Physiol 296: R1113-R1123, 2009. First published January 14, 2009; doi: 10.1152/ajpregu.90361.2008.-Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats after intratracheal instillation of the same dose of elastase/body weight. Although species variations in antielastase defenses may largely explain these results, other variables, such as differences in lung antioxidants, cannot be overlooked since oxidative stress modulates antiprotease activity. We propose that elastase instillation might affect lung glutathione (GSH) metabolism differently in these species. Our aim was to study in hamsters and rats, lung glutathione metabolism at different times, from the stage of diffuse alveolar damage to advanced emphysema. We measured total and oxidized glutathione content as well as activity and expression of enzymes related to GSH synthesis and redox cycling: gamma-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase. Whereas rats showed no significant changes in these measurements, hamsters showed significant derangement in GSH metabolism early after elastase instillation: 25% fall in total GSH (P < 0.05) with no increase in oxidized glutathione associated with reduced enzyme activities 24 h after elastase [60% for gamma-glutamylcysteine synthetase (P < 0.01), 30% for glutathione peroxidase (P < 0.01), and 75% for glutathione reductase (P < 0.001)]. GSH homeostasis was restored at the end of the first week, involving transient increased expression of these enzymes. We conclude that elastase induces significant alterations in GSH metabolism of hamster lungs and no overall change in rat lungs. Although differences in disease severity may account for our findings, the hamster becomes vulnerable to functional inhibition of alpha(1)-antitrypsin by oxidants and thus, even more susceptible to injury than it would be, considering only its low alpha(1)-antitrypsin level.
- ItemMitochondrial diabetes and deafness: Possible dysfunction of strial marginal cells of the inner ear(2011) Olmos, Pablo R.; Borzone, Gisella; Olmos, Juan P.; Diez, Alberto; Santos Martín, José Luis; Serrano, Valentina; Cataldo, Luis R.; Anabalón, José L.; Correa, Claudio H.Objective: Some patients with the syndrome of mitochondrial diabetes and deafness (MIDD) have a m.3243A>G mutation of the MTTL1 gene encoding transfer ribonucleic acid for the amino acid leucine (tRNALeu(UUR)). One of our MIDD patients inspired us to propose an integrated view on how a single mutation of the mitochondrial deoxyribonucleic acid (DNA) affects both the glucose metabolism and the inner ear physiology. Design: (a) Study of mitochondrial DNA in a patient with MIDD. (b) Review of the literature on the impact of the m.3243A.G mutation on glucose metabolism and on the physiology of the hearing process. Settings: Outpatient diabetes and nutrition department and molecular nutrition laboratory. Methods: (a) Polymerase chain reaction followed by restriction fragment analysis identified the m.3243A>G mutation. (b) Review of the literature from 1994 to 2009. Results: (a) Molecular study: the m.3243A>G mutation was detected with an appreciable level of heteroplasmy. (b) Review of the literature: the strial marginal cells located near the organ of Corti fulfill two characteristics: they are rich in mitochondria, and their dysfunction may produce neurosensorial deafness by means of a reduction in the potassium ion concentration of the endolymph. Conclusions: The m.3243A>G mutation not only underlies a dysfunction of the insulin-producing beta cell of the pancreas but also results in a reduction in adenosine triphosphate production of the strial marginal cells of the inner ear, thus diminishing the energy (in the form of potassium ion gradient) needed for the outer hair cells of the organ of Corti to amplify the soundwaves, particularly at high frequencies. © 2011 The Canadian Society of Otolaryngology-Head & Neck Surgery.
- ItemNear-optimal glycemic control in Chilean women with pregestational type-2 diabetes: Persistent macrosomia relates to maternal pre-pregnancy overweight(ELSEVIER IRELAND LTD, 2009) Olmos, Pablo R.; Araya Del Pino, Andrea P.; Gonzalez Carvello, Cristian A.; Laso Ulloa, Pablo; Hodgson, Maria I.; Irribarra, Veronica; Borzone, Gisella R.; Belmar, Cristian; Poblete, Andres; Berrios, Cecilia; Becker, Jorge; Zajer Amar, Claudia M.; Manzur, Alejandro; Bozinovic, Milan; Miranda, Ramon J.; Diez, Alberto; Vidal, Hernan; Ramirez Armijo, Renato; Olmos, Roberto I.; Tabilo, Cristian; Ahuad, JessicaAfter a 10-year program intending to improve glycemic control in diabetic pregnancies, we evaluated whether factors underlying macrosomia are similar for type-1 and -2 pregestational diabetic women.