Browsing by Author "Morales, Mauricio"

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    11β-hydroxysteroid dehydrogenase type 2 polymorphisms and activity in a Chilean essential hypertensive and normotensive cohort.
    (2012) Campino, Carmen; Quinteros, Hector; Owen, Gareth I.; Carvajal, Cristian A.; Morales, Mauricio; Olivieri, Oliviero; Guidi, Giancesare; Faccini, Giovanni; Pasini, Francesco; Baudrand, Rene; Padilla, Oslando; Valdivia, Carolina; Thichauer, Juan; Lagos, Carlos F.; Kalergis, Alexis M.; Fardella, Carlos E.
    BACKGROUND: 11β-hydroxysteroid dehydrogenase type 2 enzyme (11β-HSD2) inactivates cortisol (F) to cortisone (E); its impairment is associated with hypertension. We reported that 15.7% of the Chilean essential hypertensives possessed a high F/E ratio suggesting a partial deficit in 11β-HSD2 activity. It has been reported that the G534A(Glu178/Glu) polymorphism in the HSD11B2 gene is associated with hypertension. Investigate the frequency of the G534A polymorphism and its correlation with the glucocorticoid profile in Chilean essential hypertensive and normotensive subjects. METHODS: Essential hypertensive outpatients (n = 232) and normotensive subjects (n = 74) were recruited. A change in the AluI restriction enzyme digest pattern, caused by the presence of the G534A polymorphism, was utilized to screen DNA isolated from leukocytes within the cohort before confirmation by sequencing. Plasma renin activity (PRA), serum aldosterone, F, and E were measured by radioimmunoassay. Urinary tetrahydrocortisol (THF), 5α-tetrahydrocortisol (5α-THF), and tetrahydrocortisone (THE) were measured by gas chromatography-mass spectrometry. RESULTS: G534A polymorphism frequency was similar between hypertensive patients (19 of 232; 8.2%) and normotensive subjects (7 of 74; 9.5%). When categorized by presence or absence of the G534A polymorphism, no significant differences in the serum F/E ratio or other measured biochemical variables were detected. Despite a previous report that the G534A polymorphism is associated with a neighboring C468A (Thr156/Thr) polymorphism, analysis within our cohort showed that only one patient in each group presented with this double polymorphism. CONCLUSIONS: We report the frequency of the G534A polymorphism in the Spanish-Amerindian population. No correlation was detected between this polymorphism and the presence of hypertension and biochemical parameters in this Chilean cohort.
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    Dinámicas urbanas en territorio indígena: transformación en las formas de habitar mapuche en el lof Rengalil, Labranza (región de la Araucanía, Chile)
    (2022) Nuñez Marengo, Amapola Isabel; Riquelme Maulén, Wladimir Esteban; Salazar Preece, Gonzalo; Maturana, Francisco; Morales, Mauricio
    Las formas de habitar mapuche son diversas y heterogéneas, constituidas en parte por prácticas residenciales que integran el medio circundante, la naturaleza y los sitios de significación cultural. En la región de la Araucanía, al sur de Chile, se ha urbanizado sobre territorio indígena, lo que ha transformado las prácticas y movilidades de habitantes mapuche que actualmente intentan preservar sus modos de vida ancestrales enmarcados en luchas explícitas por el cuidado de la tierra y naturaleza. Este artículo demuestra que la urbanización acelerada del territorio ancestral indígena implica también transformaciones en las prácticas y acciones cotidianas espacializadas, y da cuenta de una arista escasamente estudiada de la geografía mapuche en entornos urbanos
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    Evaluación de la insulinemia post carga oral de glucosa como método diagnóstico de resistencia a la insulina
    (2014) Arancibia, Constanza; Galgani Fuentes, José; Valderas Igor, Juan Patricio; Morales, Mauricio; Santos Martin, José Luis; Pollak Cornejo, Felipe
    Background: In our country, the assessment of insulin resistance (IR) measuring serum insulin levels at 60 and 120 minutes after a 75 g oral glucose tolerance test (OGTT), is usual. However, there is no information about the distribution of serum insulin levels in the Chilean population. Aim: To assess the distribution of serum insulin levels at 60 and 120 minutes during OGTTs and suggest a statistical cut-off point to estimate the degree of IR. Material and Methods: Retrospective analysis of 1815 OGTTs performed in non-diabetic subjects aged between 18 and 75 years, at a university medical center. HOMA-IR (Homeostasis Model Assessment), insulin sensitivity index of Matsuda (ISI-Composite), and their correlation with serum insulin levels at 60 and 120 minutes were calculated. Results: The 75th percentiles for serum insulin levels at 60 and 120 minutes were 127 and 81 μU/mL, respectively. There was a high correlation between HOMA-IR and ISI-Composite (r = -089, p < 0.001). There was a weaker although significant correlation between HOMA-IR and ISI-Composite and insulin levels at 60 (r = 0.56 and -0.79 respectively, p < 0,001) and 120 minutes (r = 0.54 and -0.75 respectively, p < 0,001). Conclusions: We propose 60 and 120 min serum insulin levels of 130 and 80 μU/mL respectively, as cut-off values for normality during OGTT in Chilean normoglycemic individuals.
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    Future land use conflicts: Comparing spatial scenarios for urban-regional planning
    (SAGE PUBLICATIONS LTD, 2022) Henriquez, Cristian; Morales, Mauricio; Quense, Jorge; Hidalgo, Rodrigo
    Latin America's intensive urbanization processes are triggering rapid peri-urban transformations and the expansion of cities. These include accelerated metropolization processes, urban sprawl, and the emergence of new conurbations. These changes parallel the expansion of highly profitable agricultural activities and plantations linked to international markets. This paper aims to analyze land use/cover changes between 1990 and 2050 in the Quillota Province, Valparaiso Region, Chile. Specific objectives considered (1) analyzing changes in land use/cover trajectories between 1990 and 2017, (2) simulating changes in land use/cover based on three scenarios of territorial planning to 2050 (trending, ecological planning, and spatial planning), and (3), identifying the areas most likely to be modified by urbanization and agricultural activity as a result of biodiversity loss in the study area. The Dyna-CLUE model implemented was complemented with GIS techniques for the analysis of land use/cover trajectories that allowed classifying and characterizing the most dynamic land uses/cover within the Quillota Province, such as urban land uses. The results of simulations to 2050 show a probable conurbation of medium-sized cities of Quillota-La Cruz-Calera, and future land use conflicts between peri urban-agricultural land use and plantation-natural conservation land use. The results suggest that it is essential to choose scenarios to ensure sustainable land use planning to control urban and peri-urban sprawl and protect areas of high natural value.
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    Overexpression of 11 beta-Hydroxysteroid Dehydrogenase Type 1 in Hepatic and Visceral Adipose Tissue is Associated with Metabolic Disorders in Morbidly Obese Patients
    (SPRINGER, 2010) Baudrand, Rene; Carvajal, Cristian A.; Riquelme, Arnoldo; Morales, Mauricio; Solis, Nancy; Pizarro, Margarita; Escalona, Alex; Boza, Camilo; Perez, Gustavo; Dominguez, Angelica; Arrese, Marco; Fardella, Carlos E.
    The enzyme 11-beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) catalyzes intracellular glucocorticoid reactivation by conversion of cortisone to cortisol in different tissues and have been implicated in several metabolic disorders associated with obesity. The aim of this study was to evaluate the 11 beta-HSD1 expression in liver, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) in morbidly obese patients undergoing bariatric surgery and its correlations with clinical, anthropometric, and biochemical variables.
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    Overexpression of 11 beta-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue and portal hypercortisolism in non-alcoholic fatty liver disease
    (WILEY, 2012) Candia, Roberto; Riquelme, Arnoldo; Baudrand, Rene; Carvajal, Cristian A.; Morales, Mauricio; Solis, Nancy; Pizarro, Margarita; Escalona, Alex; Carrasco, Gonzalo; Boza, Camilo; Perez, Gustavo; Padilla, Oslando; Cerda, Jaime; Fardella, Carlos E.; Arrese, Marco
    Background: The enzyme 11 beta-hydroxysteroid-dehydrogenase type 1 (11 beta HSD1) catalyses the reactivation of intracellular cortisol. We explored the potential role of 11 beta-HSD1 overexpression in visceral adipose tissue (VAT) in non-alcoholic fatty liver disease (NAFLD) assessing sequential changes of enzyme expression, in hepatic and adipose tissue, and the occurrence of portal hypercortisolism in obese mice. 11 beta-HSD1 expression was also assessed in tissues from obese patients undergoing bariatric surgery. Methods: Peripheral and portal corticosterone levels and liver histology were assessed in ob/ob mice at two time points (8-12 weeks of age). 11 beta-HSD1 tissue expression was assessed in by RT-pcr in ob/ob mice and in 49 morbidly obese patients. Results: Portal corticosterone serum levels were higher in obese mice with a 26% decrease between 8 and 12 weeks of age (controls: 78.3 +/- 19.7 ng/ml, 8-week-old ob/ob: 167.5 +/- 14.5 ng/ml and 12-week-old ob/ob: 124.3 +/- 28 ng/ml, P < 0.05). No significant differences were found in peripheral corticosterone serum levels. Expression of 11b-HSD1 was lower in the liver [-45% at 8 weeks and -35% at 12-weeks (P = 0.0001)] and highly overexpressed in VAT in obese mice, compared to controls (128-fold higher in 8-week-old ob/ob and 41-fold higher in 12-week-old ob/ob, P < 0.01). No significant differences were seen in the expression of 11 beta-HSD1 in subcutaneous adipose tissue. In multivariate analysis, human 11 beta-HSD1 expression in VAT (OR: 1.385 +/- 1.010-1.910) was associated with NAFLD. Conclusion: Murine NAFLD is associated with portal hypercortisolism and 11 beta-HSD1 overexpression in VAT. In humans, 11 beta-HSD1 VAT expression was associated with the presence of NAFLD. Thus, local corticosteroid production in VAT may contribute to NAFLD pathogenesis.
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    Overexpression of hepatic 5 alpha-reductase and 11 beta-hydroxysteroid dehydrogenase type 1 in visceral adipose tissue is associated with hyperinsulinemia in morbidly obese patients
    (W B SAUNDERS CO-ELSEVIER INC, 2011) Baudrand Biggs Rene Felipe; Domínguez Ruiz-tagle, José Miguel; Carvajal, Cristian A.; Riquelme, Arnoldo; Campino, Carmen; Macchiavello, Stefano; Bozinovic, Milan; Morales, Mauricio; Pizarro, Margarita; Solis, Nancy; Escalona, Alex; Boza, Camilo; Arrese, Marco; Fardella, Carlos E.
    11 beta-Hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) converts cortisone to cortisol, mainly in the liver and visceral adipose tissue (VAT), and has been implicated in several metabolic disorders. The absence of systemic hypercortisolism in central obesity could be due to increased inactivation of cortisol to its tetrahydrometabolites by the hepatic enzymes 5 alpha-and 5 beta-reductases. Our aim was to assess the expression of the reductases in the liver and of 11 beta-HSD1 in the liver and VAT in morbidly obese patients and to analyze their association with clinical, anthropometric, and biochemical parameters. Hepatic and VAT samples were obtained during bariatric surgery. 5 alpha- and 5 beta-reductases, 11 beta-HSD1, and 18S expression was measured using real-time polymerase chain reaction. Anthropometric and biochemical variables were analyzed. Forty-one patients were recruited (age, 41.8 +/- 10.6 years; body mass index, 42.1 +/- 6.6 kg/m(2); 71% women). The expression of hepatic 5 alpha- and 5 beta-reductases was positively correlated (r = +0.53, P = .004), and their expression levels were correlated with hepatic 11 beta-HSD1 expression (r = +0.61, P < .001 for 5 alpha-reductase and r = +0.50, P < .001 for 5 beta-reductase). Hepatic 5 alpha-reductase was associated with insulin (r = +0.34, P = .015). Visceral adipose tissue 11 beta-HSD1 expression was associated with glucose (r = +0.37, P = .025) and insulin (r = +0.54, P = .002). Our results showed that 5 alpha-reductase and VAT 11 beta-HSD1 expressions were associated with insulinemia. These findings suggest that overexpression of 5 alpha-reductase, through a higher inactivation of cortisol in the liver, could have a protective role in preserving hepatic sensitivity to insulin. The overexpression of liver reductases in obesity could be an adaptive response to an increase in cortisol production by the liver and visceral 11 beta-HSD1 to avoid systemic hypercortisolism. (C) 2011 Elsevier Inc. All rights reserved.