Browsing by Author "Allende Sanzana, Fidel Alejandro"

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    Heterocyclic amines in chicken meat: Development of new technologies for their quantification and mitigation
    (2024) Allende Sanzana, Fidel Alejandro; Pedreschi Plasencia, Franco; Solari Gajardo, Sandra; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    Las carnes, son una fuente de alimentación ampliamente utilizadas, por ser ricas en proteínas, minerales y otros nutrientes. En Chile, hay un aumento sostenido en el consumo de carnes, principalmente de carne de pollo. El 2013 se consumieron ~38 kg/año de carne de pollo per cápita (ODEPA), más del doble del promedio per cápita mundial (~16 kg). Por su parte, los procesos de calentamiento de carne a alta temperatura (150 a 250°C) la hacen más segura microbiológicamente y más apetitosa con los cambios de textura, apariencia y sabor, pero también, debido a la reacción de Maillard, se forman Aminas Heterocíclicas (HAs). Las HA son un grupo de contaminantes cancerígenos según la OMS, se forman en el proceso de cocción de la carne a alta temperatura y han sido asociados con cáncer de colon y otras patologías en diferentes estudios. En modelos animales han demostrado el desarrollo de tumores en el colon y otros órganos. Mientras que en Chile, el cáncer de colon se ubica entre los cánceres de mayor prevalencia. Actualmente, no se dispone en Chile de metodologías y tecnologías sensibles y específicas para cuantificar y mitigar HAs asociadas al proceso de cocción de carnes a alta temperatura. Por lo tanto, nuestros objetivos fueron Desarrollar nuevas metodologías y tecnologías sensibles y específicas por LC-MS, para cuantificar y mitigar HAs generadas en el proceso de cocción de carne de pollo a alta temperatura. Por lo tanto, se desarrolló una nueva metodología analítica utilizando QUECHERS-LC-MS/MS para cuantificar los HAs generados en carne de pollo cocida a diferentes temperaturas. Además, se ha desarrollado una nueva tecnología para mitigar la formación de HAs en la carne de pollo durante la cocción. Esta innovación se basó en la aplicación de extractos de vainas de Tara (Caesalpinia spinosa). Los resultados de la nueva metodología analítica desarrollada fueron: (i) Recuperación >82%; (ii) Efecto Matriz (92-103%); (iii) CV (3,7-11,4%) (iv) Precisión (103-115%); (iv) LOD 0,1 ng/g; (vi) LOQ 1 ng/g, cumpliendo con los parámetros de validación de la FDA. Finalmente, la tecnología de mitigación de HAs implementada, basada en extractos de vainas de Tara, reduce en promedio un 70 % del total de HAs producidos en la carne de pollo durante la cocción, convirtiéndose en una alternativa natural altamente eficaz, que aprovecha los compuestos bioactivos para la mitigación.
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    PS 10-19 Serum cortisone and cortisol/cortisone ratio as tool to identify subjects with severe and partial 11beta-hydroxysteroid dehydrogenase type 2 deficiencies
    (LIPPINCOTT WILLIAMS & WILKINS, 2016) Carvajal Maldonado, Cristian Andrés; Tapia Castillo, Alejandra; Martínez Aguayo, Alejandro Gregorio; Valdivia, Carolina; Campino Johnson, María Del Carmen; Baudrand Biggs, Rene Felipe; Allende Sanzana, Fidel Alejandro; Pinochet Valenzuela, Constanza; Iturrieta González, Virginia Andrea; Lizama, Jaime; Solari Gajardo, Sandra; Fardella Bello, Carlos Enrique
    Objective: To report the phenotype of patients with AME by clinical and biochemical study, and expanding the study to their families and unrelated subjects to assess the value of F/E ratio as a biomarker partial deficiency of 11βHSD2.Design and Method: We evaluated 2 AME patients and their families. Family 1: A 17 years-old male with a homozygous Asp223Asn (D223N) mutation in HSD11B2, his mother (33 years) and sister (8 years); and Family 2: A 2 years-old girl with a homozygous Arg213Cys (R213C) mutation in HSD11B2, his father (30 years), her mother (30 years) and sister (6 years). We measured serum potassium, aldosterone, plasma renin activity (PRA), microalbuminuria, NGAL and F/E ratio (HPLC-MS). Reference ranges (RR), percentiles (p) and cut-off points for F, E and F/E serum were determined on data obtained from adult and pediatric normotensive subjects (F/E children RR: 1.63 to 5.15 and F/E adults RR:2.6–7.8]). Genetic analyses were performed by PCR-HRM and DNA sequencing.Results: Family 1: Index case (mut D223N) with classical AME features and a high serum F/E ratio (28.8 (> p99)). His mother and sister were normotensive and heterozygous for the same mutation D223N without clinical and biochemical abnormalities but with high F/E ratios (13.1 (p97) and 7.4 (p97)), respectively). Family 2: Index case (mut R213C) with classical AME and and a high F/E (175 (>p99)). His father, mother and sister were heterozygous for R123C, and are clinically and biochemically normal except for high F/E ratios (p92, p93 and p85, respectively).Conclusions: A F/E ratio greater than p90 –often associated to a cortisone lesser than p30- in relatives of subjects with AME suggests that partial heterozygous alterations or deficit in HSD11B2 are able to be identified by studying the serum cortisone and F/E ratio without prior clinical or biochemical features of classic AME such as AH, suppressed PRA and hypokalemia.
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    Testosterona inhibe la actividad de la aldosterona sintasa silvestre y quimérica in vitro
    (Sociedad Medica de Santiago, 2021) Vecchiola Cardenas, Andrea Paola; Saldias Fuentes, Cristóbal Abraham; Carvajal Maldonado, Cristian Andrés; Campino Johnson, María Del Carmen; Allende Sanzana, Fidel Alejandro; Tapia-Castillo, Alejandra; Lagos, Carlos F.; Fardella Bello, Carlos Enrique
    © 2021 Sociedad Medica de Santiago. All rights reserved.Background: Familial hyperaldosteronism type I is caused by the generation of a chimeric aldosterone synthase enzyme (ASCE) which is regulated by ACTH instead of angiotensin II. We have reported that in vitro, the wild-type (ASWT) and chimeric aldosterone synthase (ASCE) enzymes are inhibited by progesterone and estradiol does not affect their activity. Aim: To explore the direct action of testosterone on ASWT and ASCE enzymes. Material and Methods: HEK-293 cells were transiently transfected with vectors containing the full ASWT or ASCE cDNAs. The effect of testosterone on AS enzyme activities was evaluated incubating HEK-cells transfected with enzyme vectors and adding deoxycorticosterone (DOC) alone or DOC plus increasing doses of testosterone. Aldosterone production was measured by HPLC-MS/MS. Docking of testosterone within the active sites of both enzymes was performed by modelling in silico. Results: In this system, testosterone inhibited ASWT (90% inhibition at five µM, 50% inhibitory concentration (IC50) =1.690 µM) with higher efficacy and potency than ASCE (80% inhibition at five µM, IC50=3.176 µM). Molecular modelling studies showed different orientation of testosterone in ASWT and ASCE crystal structures. Conclusions: The inhibitory effect of testosterone on ASWT or ASCE enzymes is a novel non-genomic testosterone action, suggesting that further clinical studies are needed to assess the role of testosterone in the screening and diagnosis of primary aldosteronism.