Examinando por Autor "Opazo, Ma. Cecilia"
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Ítem Asymptomatic Herpes Simplex Virus Type 1 Infection Causes an Earlier Onset and More Severe Experimental Autoimmune Encephalomyelitis(Frontiers Media S.A., 2021-02) Duarte, Luisa F.; Altamirano Lagos, María J.; Tabares Guevara, Jorge H.; Opazo, Ma. Cecilia; Díaz, Máximo; Navarrete, Romina; Muza, Catalina; Vallejos, Omar P.; Riedel, Claudia A.; Bueno, Susan M.; Kalergis, Alexis M.; González, Pablo A.Multiple sclerosis (MS) is an increasingly prevalent progressive autoimmune and debilitating chronic disease that involves the detrimental recognition of central nervous system (CNS) antigens by the immune system. Although significant progress has been made in the last decades on the biology of MS and the identification of novel therapies to treat its symptoms, the etiology of this disease remains unknown. However, recent studies have suggested that viral infections may contribute to disease onset. Interestingly, a potential association between herpes simplex virus type 1 (HSV-1) infection and MS has been reported, yet a direct relationship among both has not been conclusively demonstrated. Experimental autoimmune encephalomyelitis (EAE) recapitulates several aspects of MS in humans and is widely used to study this disease. Here, we evaluated the effect of asymptomatic brain infection by HSV-1 on the onset and severity of EAE in C57BL/6 mice. We also evaluated the effect of infection with an HSV-1-mutant that is attenuated in neurovirulence and does not cause encephalitis. Importantly, we observed more severe EAE in mice previously infected either, with the wild-type (WT) or the mutant HSV-1, as compared to uninfected control mice. Also, earlier EAE onset was seen after WT virus inoculation. These findings support the notion that a previous exposure to HSV-1 can accelerate and enhance EAE, which suggests a potential contribution of asymptomatic HSV-1 to the onset and severity of MS. © Copyright © 2021 Duarte, Altamirano-Lagos, Tabares-Guevara, Opazo, Díaz, Navarrete, Muza, Vallejos, Riedel, Bueno, Kalergis and González.Ítem Excess iodide induces an acute inhibition of the sodium/iodide symporter in thyroid male rat cells by increasing reactive oxygen species(Endocrine Society, 2015-04) Arriagada, Alejandro A.; Albornoz, Eduardo; Opazo, Ma. Cecilia; Becerra, Alvaro; Vidal, Gonzalo; Fardella, Carlos; Michea, Luis; Carrasco, Nancy; Simon, Felipe; Elorza, Alvaro A.; Bueno, Susan M.; Kalergis, Alexis M.Na+/I− symporter (NIS) mediates iodide (I−) uptake in the thyroid gland, the first and rate-limiting step in the biosynthesis of the thyroid hormones. The expression and function of NIS in thyroid cells is mainly regulated by TSH and by the intracellular concentration of I−. High doses of I− for 1 or 2 days inhibit the synthesis of thyroid hormones, a process known as the Wolff-Chaikoff effect. The cellular mechanisms responsible for this physiological response are mediated in part by the inhibition of I− uptake through a reduction of NIS expression. Here we show that inhibition of I− uptake occurs as early as 2 hours or 5 hours after exposure to excess I− in FRTL-5 cells and the rat thyroid gland, respectively. Inhibition of I− uptake was not due to reduced NIS expression or altered localization in thyroid cells. We observed that incubation of FRTL-5 cells with excess I− for 2 hours increased H2O2 generation. Furthermore, the inhibitory effect of excess I− on NIS-mediated I− transport could be recapitulated by H2O2 and reverted by reactive derived oxygen species scavengers. The data shown here support the notion that excess I− inhibits NIS at the cell surface at early times by means of a posttranslational mechanism that involves reactive derived oxygen species.Ítem Gut microbiota short-chain fatty acids and their impact on the host thyroid function and diseases(Frontiers Media SA, 2023) Mendoza-León, María José; Mangalam, Ashutosh K.; Regaldiz, Alejandro; González-Madrid, Enrique; Rangel-Ramírez, Ma. Andreina; Álvarez-Mardonez, Oscar; Vallejos, Omar P.; Méndez, Constanza; Bueno, Susan M.; Melo-González, Felipe; Duarte, Yorley; Opazo, Ma. CeciliaThyroid disorders are clinically characterized by alterations of L-3,5,3’,5’-tetraiodothyronine (T4), L-3,5,3’-triiodothyronine (T3), and/or thyroid-stimulating hormone (TSH) levels in the blood. The most frequent thyroid disorders are hypothyroidism, hyperthyroidism, and hypothyroxinemia. These conditions affect cell differentiation, function, and metabolism. It has been reported that 40% of the world’s population suffers from some type of thyroid disorder and that several factors increase susceptibility to these diseases. Among them are iodine intake, environmental contamination, smoking, certain drugs, and genetic factors. Recently, the intestinal microbiota, composed of more than trillions of microbes, has emerged as a critical player in human health, and dysbiosis has been linked to thyroid diseases. The intestinal microbiota can affect host physiology by producing metabolites derived from dietary fiber, such as short-chain fatty acids (SCFAs). SCFAs have local actions in the intestine and can affect the central nervous system and immune system. Modulation of SCFAs-producing bacteria has also been connected to metabolic diseases, such as obesity and diabetes. In this review, we discuss how alterations in the production of SCFAs due to dysbiosis in patients could be related to thyroid disorders. The studies reviewed here may be of significant interest to endocrinology researchers and medical practitioners. Copyright © 2023 Mendoza-León, Mangalam, Regaldiz, González-Madrid, Rangel-Ramírez, Álvarez-Mardonez, Vallejos, Méndez, Bueno, Melo-González, Duarte, Opazo, Kalergis and Riedel.Ítem Machine learning applied in maternal and fetal health: a narrative review focused on pregnancy diseases and complications(Frontiers Media S.A., 2023) Mennickent, Daniela; Rodríguez, Andrés; Opazo, Ma. Cecilia; Riedel, Claudia A.; Castro, Erica; Eriz-Salinas, Alma; Appel-Rubio, Javiera; Aguayo, Claudio; Damiano, Alicia E.; Guzmán-Gutiérrez, Enrique; Araya, JuanIntroduction: Machine learning (ML) corresponds to a wide variety of methods that use mathematics, statistics and computational science to learn from multiple variables simultaneously. By means of pattern recognition, ML methods are able to find hidden correlations and accomplish accurate predictions regarding different conditions. ML has been successfully used to solve varied problems in different areas of science, such as psychology, economics, biology and chemistry. Therefore, we wondered how far it has penetrated into the field of obstetrics and gynecology. Aim: To describe the state of art regarding the use of ML in the context of pregnancy diseases and complications. Methodology: Publications were searched in PubMed, Web of Science and Google Scholar. Seven subjects of interest were considered: gestational diabetes mellitus, preeclampsia, perinatal death, spontaneous abortion, preterm birth, cesarean section, and fetal malformations. Current state: ML has been widely applied in all the included subjects. Its uses are varied, the most common being the prediction of perinatal disorders. Other ML applications include (but are not restricted to) biomarker discovery, risk estimation, correlation assessment, pharmacological treatment prediction, drug screening, data acquisition and data extraction. Most of the reviewed articles were published in the last five years. The most employed ML methods in the field are non-linear. Except for logistic regression, linear methods are rarely used. Future challenges: To improve data recording, storage and update in medical and research settings from different realities. To develop more accurate and understandable ML models using data from cutting-edge instruments. To carry out validation and impact analysis studies of currently existing high-accuracy ML models. Conclusion: The use of ML in pregnancy diseases and complications is quite recent, and has increased over the last few years. The applications are varied and point not only to the diagnosis, but also to the management, treatment, and pathophysiological understanding of perinatal alterations. Facing the challenges that come with working with different types of data, the handling of increasingly large amounts of information, the development of emerging technologies, and the need of translational studies, it is expected that the use of ML continue growing in the field of obstetrics and gynecology. Copyright © 2023 Mennickent, Rodríguez, Opazo, Riedel, Castro, Eriz-Salinas, Appel-Rubio, Aguayo, Damiano, Guzmán-Gutiérrez and Araya.Ítem Transient gestational hypothyroxinemia accelerates and enhances ulcerative colitis-like disorder in the male offspring(Frontiers Media SA, 2024-01) Rivera, Juan Carlos; Opazo, Ma. Cecilia; Hernández-Armengol, Rosario; Álvarez, Oscar; Mendoza-León, María José; Caamaño, Esteban; Gatica, Sebastian; Bohmwald, Karen; Bueno, Susan M.; González, Pablo A.; Neunlist, Michel f; Boudin, Helene fIntroduction: Gestational hypothyroxinemia (HTX) is a condition that occurs frequently at the beginning of pregnancy, and it correlates with cognitive impairment, autism, and attentional deficit in the offspring. Evidence in animal models suggests that gestational HTX can increase the susceptibility of the offspring to develop strong inflammation in immune-mediated inflammatory diseases. Ulcerative colitis (UC) is a frequent inflammatory bowel disease with unknown causes. Therefore, the intensity of ulcerative colitis-like disorder (UCLD) and the cellular and molecular factors involved in proinflammatory or anti-inflammatory responses were analyzed in the offspring gestated in HTX (HTX-offspring) and compared with the offspring gestated in euthyroidism (Control-offspring). Methods: Gestational HTX was induced by the administration of 2-mercapto-1- methylimidazole in drinking water to pregnant mice during E10–E14. The HTXoffspring were induced with UCLD by the acute administration of dextran sodium sulfate (DSS). The score of UCLD symptomatology was registered every day, and colon histopathology, immune cells, and molecular factors involved in the inflammatory or anti-inflammatory response were analyzed on day 6 of DSS treatment. Results: The HTX-offspring displayed earlier UCLD pathological symptoms compared with the Control-offspring. After 6 days of DSS treatment, the HTXoffspring almost doubled the score of the Control-offspring. The histopathological analyses of the colon samples showed signs of inflammation