Browsing by Author "Rojas, A"

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    Free urinary cortisol is elevated in patients with low-renin essential hypertension
    (2004) Krall, P; Mosso, L; Carvajal, C; Rojas, A; Fardella, C
    Background: Glucocorticoids play a key role in blood pressure (BP) control and are associated with hypertension in patients with Cushing's syndrome. A number of reports indicate that cortisol (F) may be involved in etiology of essential hypertension (EH). F can bind to the mineralocorticoid receptor, triggering both sodium and water reabsorption in kidney, increase BP and cause renin suppression. Aim: To evaluate urinary free cortisol (UFF) excretion as a potential intermediate phenotype of essential hypertension and correlate F level with plasma renin activity (PRA) and serum aldosterone (SA). Patients and Methods: We recruited 132 EH patients and 16 normotensive healthy controls. Blood samples and 24 hours urine were collected for PRA, SA and UFF analysis. Differences in UFF excretion between sexes were normalized by urinary creatinine (Creat) excretion. The upper limit of UFF/Creat was determined in normotensives considering the mean value plus 2 standard deviations. According to this value, subjects were classified as having high or normal UFF. Results: In EH patients and in normotensives, the UFF/Creat was 36.9 +/- 17.0 mug/gr and 30.9 +/- 8.8 mug/gr, respectively. The upper limit was set at 48.5 mug/gr. A high UFF/Creat was found in 20/132 EH (15%) patients and 0/16 normotensive subjects. EH patients with high UFF showed lower PRA levels than patients with normal cortisol levels (0.78 +/- 0.47 vs 1.13 +/- 0.66 ng/ml*h, respectively, p = 0.027) and lower SA values (4.52 +/- 1.65 vs 6.34 +/- 3.37 ng/dl, respectively, p = 0.018). There was a negative correlation between UFF and PRA (r = -0.176, p = 0.044) and between UFF and SA (r = -0.183, p = 0.036). Conclusions: We have identified a subgroup of EH patients with increased UFF excretion. Patients with the highest UFF showed lower renin and aldosterone levels. These data suggest a potential influence of cortisol in the genesis of hypertension.
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    Genetic variation in P450c11AS in Chilean patients with low renin hypertension
    (ENDOCRINE SOC, 1996) Fardella, CE; Rodriguez, H; Montero, J; Zhang, GR; Vignolo, P; Rojas, A; Villarroel, L; Miller, WL
    Low renin hypertension (LRH), which accounts for 10-20% of patients with idiopathic ''essential'' hypertension, bears hormonal similarities to mineralocorticoid-induced hypertension, but elevated mineralocorticoid concentrations have not been found. Some patients with LRH have normal, rather than suppressed, plasma aldosterone concentrations, so that the ratio of aldosterone concentration to PRA (Aldo/PRA) is high, suggesting inappropriately increased aldosterone biosynthesis. We characterized the CYP11B2 gene that encodes the aldosterone synthase, P450c11AS, in hypertensive and control populations in a single clinic in Santiago, Chile. We directly sequenced the entire CYP11B2 gene in 12 patients with LRH, 2 high renin hypertensive controls, and 2 normotensive controls. All sequences were identical, except that 8 of 24 LRH alleles encoded arginine rather than lysine at position 173. The Arg(173) and Lys(173) variants were expressed in transfected MA-10 cells, and their ability to convert deoxycorticosterone to aldosterone was measured; the apparent Michaelis constant (K-m) for Lys(173) was 2.73 mu mol/L; the K-m for Arg(173) was 2.53 mu mol/L. The apparent maximal velocity (V-max) for Lys(173) was 6.5x10(-3) mu g/mL . 24 h; the V-max for Arg(173) was 7.8x10(-3) mu g/mL . 24 h. The first order rate constant, V-max/K-m was 2.38 for Lys(173) and 3.08 for Arg(173). As these values were not significantly different, we sought to determine whether Arg(173) is a polymorphism linked to LRH. We examined position 173 in 52 unselected patients with idiopathic hypertension and 55 normotensive controls by PCR amplification of CYP11B2 exons 3-5 followed by digestion with Bsu36I, which digests the Arg(173) sequence, but not the Lys(173) sequence. More of the hypertensive alleles (39 of 104, 37.5%) than normotensive alleles (25 of 110, 22.5%) carried Arg(173) (chi(2)=5.57; P <0.02). Most of the Arg(173) alleles (31 of 72, 43.1%) were from hypertensive patients with Aldo/PRA below 30, whereas only 5 of 24 (20.8%) Arg(173) alleles were found in patients with Aldo/PRA greater than 30 (chi(2)=3.79; P=0.05) Thus, the Arg(173) variant of CYP11B2 may be linked to LRH in Chilean patients.
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    The A-6G mutation in the angiotensinogen gene is associated to high levels of aldosterone in essential hypertensives
    (1999) Fardella, C; Zamorano, P; Gomez, L; Oestreicher, E; Pinto, M; Rojas, A; Montero, J; Soto, J; Mosso, L; Foradori, A
    The treatment of papillary thyroid carcinoma of less than 10 mm diameter is a matter of controversy. The incidental finding of papillary microcarcinomas in autopsies is frequent and some authors postulate that these tumors are biologically inactive and should only be observed. We report a 21 years old woman with a papillary thyroid cancer of 6x5x5 mm and bilateral paratracheal metastases, that was subjected to a total thyroidectomy. She received 200 mCi of radioiodine. Two years after surgery, a new nodule of 9.6 mm diameter was detected by ultrasound, that was treated with a new dose of 200 mCi of radioiodine. One year later a suprasternal mass of 2 cm diameter and 3 enlarged lymph nodes were detected. She was subjected to a surgical lymph node dissection of the neck and the biopsy confirmed the presence of cancer. She received a new dose of 300 mCi of radioiodine. The mother of the patient had a 7 mm thyroid nodule that was also a papillary carcinoma.
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    The terminally ill patient
    (2000) Bravo, M; Echeverria, C; Goic, A; Kottow, M; Lavados, M; Mosso, L; Perez, M; Quintana, C; Rojas, A; Rosselot, E; Serani, A; Taboada, P; Trejo, C; Soc Med Santiago; NCD Risk Factor Collaboration (NCD-RisC)
    The classification of a patient as terminally ill is based on an expert diagnosis of a severe and irreversible disease and the absence of an effective available treatment, according to present medical knowledge. Terminal diseases must not be confused with severe ones, since the latter may be reversible with an adequate and timely treatment. The physician assumes a great responsibility at the moment of diagnosing a patient as terminally ill. The professional must assume his care until the moment of death. This care must be oriented to the alleviation of symptoms and to provide the best possible quality of life. Also, help must be provided to deal with personal, legal and religious issues that may concern the patient.