Browsing by Author "Fardella B C."

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    11β-hydroxysteroid dehydrogenase activity in patients with hypertension and low plasma renin activityActividad de 11 beta hidroxiesteroide dehidrogenasa tipo 2 en hipertensos chilenos
    (2002) Fardella B C.; Mosso G L.; Carvajal M C.; Campino J C.; Rojas O A.; González P A.; Barraza M A.; Montero L J.; NCD Risk Factor Collaboration (NCD-RisC)
    Background: Half of hypertensive patients with low plasma renin activity have a primary hyperaldosteronism. Among the remaining half, 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) deficiency plays an important role. This enzyme catalyzes the conversion of cortisol to cortisone, avoiding the interaction of cortisol with the mineralocorticoid receptor. If the enzyme fails, cortisol will stimulate sodium and water reabsorption and increase blood pressure. Aim: To determine biochemical alterations, suggestive of 11βHSD2 deficiency, in low-renin hypertensive patients. Patients and Methods: Twenty eight hypertensive patients with a plasma renin activity of less than 0.5 ng/ml/h and with a plasma aldosterone of less than 5 ng/dl were studied. Twenty eight normotensive patients were studied as controls. Serum cortisol (RIA), cortisone (ELISA) and the serum cortisol/cortisone ratio were determined in all of them, between 9 and 10 AM. Measurements were confirmed by high pressure liquid chromatography. The serum cortisol/cortisone ratio was considered abnormal when its Ln (cortisol/cortisone) value was over 2 standard deviations of the mean. Results: Serum cortisol was higher in hypertensive subjects than in controls (11.1±3.3 and 9.2±2.8 μg/dl, respectively; p <0.05). No differences were observed in serum cortisone (3.4±1.3 and 3.7±1.2 μg/dl, respectively). Four hypertensive subjects had an abnormally high Ln (cortisol/cortisone) value (1.86; 1.73; 2.07 and 2.01, considering a normal value of less than 1.61). Conclusions: Four of 28 hypertensive subjects with low plasma renin activity and aldosterone had biochemical alterations suggestive of 11βHSD2 deficiency (Rev Méd Chile 2002; 130: 1201-8).
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    Free urinary cortisol is elevated in patients with low-renin essential hypertensionElevación del cortisol urinario en hipertensos esenciales hiporreninémicos
    (2004) Mosso G L.; Fardella B C.; Krall O P.; Carvajal M C.; Rojas O A.; Fardella B C.; NCD Risk Factor Collaboration (NCD-RisC)
    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 μg/gr and 30.9±8.8 μg/gr, respectively. The upper limit was set at 48.5 μg/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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    Glucocorticoid treatable hypertension. Report of one caseHipertensión arterial tratable con glucocorticoides: Comunicación de un caso
    (1997) Montero L J.; Fardella B C.; Mosso G L.; Fardella B C.
    Lately, a series of hypertensive syndromes of unknown etiology that respond to new forms of therapy, have been described. One of these is glucocorticoid remediable hypertension, that evolves with suppressed plasma renin activity and normal or high serum aldosterone levels, that lead to an aldosterone/plasma renin activity ratio over 30. We report a 45 years old woman with a severe hypertension, despite the use of antihypertensive medications. She had a plasma renin activity of less than 0.3 ng/ml/h, normal serum aldosterone levels (10 ng/ml) and thus a high aldosterone/plasma renin activity ratio. She had normal serum potassium and sodium levels. Due to the bad results of conventional antihypertensive medications, a treatment with dexamethasone was started, that normalized blood pressure and allowed to discontinue other antihypertensive medications. This type of hypertension must be sought since non conventional treatments could be used for refractory hypertensive syndromes.
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    Pathological characteristics of thyroid microcarcinoma. A review of 402 biopsiesCaracterísticas de presentación del microcarcinoma papilar del tiroides. Experiencia retrospectiva de los últimos 12 años
    (2005) Fardella B C.; Jiménez M M.; Mosso G L.; González V G.; Rodríguez P J.A.; Campusano M C.; López M J.M.; Arteaga U E.; González D H.; León R A.; Goñi E I.; Cruz O F.; Solar G A.; Torres M J.; Fardella B C.; NCD Risk Factor Collaboration (NCD-RisC)
    Background: Thyroid microcarcinoma is a tumor of 10 mm or less, that should have a low risk of mortality. However, a subgroup of these carcinomas is as aggressive as bigger tumors. Aim: To describe the pathological presentation of these tumors, and compare them with larger tumors. Material and methods: All pathological samples of thyroid carcinoma that were obtained between 1992 and 2003, were studied. In all biopsies, the pathological type, tumor size, the focal or multifocal character, the presence of lymph node involvement and the presence of lymphocytic thyroiditis or thyroid hyperplasia, were recorded. Results: One hundred eighteen microcarcinomas and 284 larger tumors were studied. The mean age of patients with microcarcinoma and larger tumors was 42.7±14 and 49.3±16 years respectively (p <0,001) and 83% were female, without gender differences between tumor types. Mean size of microcarcinomas was 8.6 mm and 116 (98%) were papillary carcinomas. Of these, 109 (94%) were well differentiated and seven (6%) were moderately differentiated. Thirty six (31%) were multifocal and in 10 (8,6%), there was lymph node involvement. The mean size of larger tumors was 23.8 mm and 241 (85%) were papillary carcinomas. Of these, 200 (83%) were well differentiated, and 41 (17%) were moderately differentiated. Eighty five (35%) were multifocal and in 44 (18%) there was lymph node involvement. The prevalence of thyroiditis and hyperplasia was significantly higher among microcarcinomas than in larger tumors (15 and 2.5%, respectively, p <0.001, for the former; 32.4 and 1.7%, respectively, p <0.001, for the latter). Conclusions: In this series, one third of microcarcinomas were multifocal and 10% had lymph node involvement. Therefore, the aggressiveness of these tumors is higher than what is reported in the literature and they should be treated with total thyroidectomy.
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    Thyroid microcarcinoma with an aggressive evolution. Report of one caseMicrocarcinoma tiroideo de evolución agresiva
    (2005) Mosso G L.; Jiménez M M.; Fardella B C.; Solar G A.; Torres M J.; González D H.; Mosso G L.
    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.