Browsing by Author "Carvajal Maldonado, Cristian Andrés"

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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.