[A novel method for targeting and characterizing healthy older people].

Background: there is no established definition of healthy aging in clinical practice, although it is a World Health Organization goal.

Aim: to develop a clinical protocol to identify healthy older people living in the community and study their clinical, laboratory and functional characteristics.

Material And Methods: healthy people aged 60 years or older, were invited to participate in the study, by newspapers and radio, if they selfperceived as healthy, lived in the community, were functionally independent and had low disease burden.

[Mutations in the Fibroblast Growth Factor Receptor 3 gene (FGFR3) in Chilean patients with idiopathic short stature, hypochondroplasia and achondroplasia].

Background: Achondroplasia and hypochondroplasia are skeletal dysplasias of autosomal dominant inheritance that represent different degrees of severity of the same pathological entity. Both dysplasias are caused by mutations in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene. In achondroplasia more than 95% of the cases studied to date carry the same mutation (G380R).

Ketoconazole alters cyclosporine pharmacokinetic profile and may predispose to acute rejection.

Ketoconazole (KET) is frequently used as a cyclosporine (CyA)-sparing agent. Adequate exposure to CyA is critical to avoid acute rejection (AR) or chronic rejection (CR). We compared the pharmacokinetic profiles of nine stable renal transplant patients on CyA before and after conversion to KET (200 mg/d of KET simultaneous with CyA).

Y chromosome sequences in Turner's syndrome: association with virilization and gonadoblastoma.

Unlabelled: The presence of Y chromosome fragments in patients with Turner's syndrome is known to increase the risk of gonadoblastoma and virilization. Y chromosome material is detected in up to 6% of patients with Turner's syndrome by karyotype. By DNA analysis, Y chromosome sequences have been reported in 0-60% of patients.

[Correlation between phenotype and genotype in a group of patients with cystic fibrosis].

Background: Cystic fibrosis (CF) is the most common lethal autosomic disease in Caucasians, with a global incidence of 1:3000 newborns. More than 900 mutations have been described, involving the Cystic Fibrosis Transmembrane Regulator (CFTR). The delta F508 mutation is present in 60% of alleles studied worldwide.

[Anti thyroglobulin antibodies in the follow up of patients with differentiated thyroid cancer: residual or relapsing disease markers?].

Background: Anti thyroglobulin antibodies are present in 25% of patients treated for a differentiated thyroid cancer, invalidating thyroglobulin determination. Those patients subjected to total thyroidectomy and free of disease, should reduce the production of these antibodies, due to the lack of antigenic stimulus. Therefore, anti thyroglobulin antibodies could be useful to detect early relapses.

Urinary vasodilator and vasoconstrictor angiotensins during menstrual cycle, pregnancy, and lactation.

Since normal human pregnancy is characterized by normotension in the face of an increased renin-angiotensin-aldosterone system (RAAS), we evaluated the temporal pattern of urinary excretion of a novel vasodilator within this system, angiotensin-(1-7) (Ang-[1-7]), during the menstrual cycle, pregnancy, and lactation. The urinary profiles of Ang I, Ang II, human chorionic gonadotropin, 17beta-estradiol, and progesterone were also determined. During the menstrual cycle, urinary Ang-(1-7) and Ang II remained stable (mean cycle value: 94.

[Identification of mutation in the gene cystic fibrosis transmembrane regulator (CFTR) in Chilean patients with cystic fibrosis].

Background: Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene, that codes for a chloride channel located in the apical surface of epithelial cells. The main role of this protein is the regulation of chloride transport, and secondarily, of sodium and water to the extracellular space. More than 900 gene mutations have been described, and their relative frequency in different populations depends on their ethnic origin.

[High prevalence of subclinical thyroidal disease among individuals attended in health control].

Background: There is no information about the prevalence of thyroidal diseases in the general Chilean population.

Aim: To assess the prevalence of thyroidal diseases in individuals attended in occupational health examinations.

Subjects And Methods: Four hundred seventy two individuals were examined between 1998 and 1999.

[Measurement of 17 OH progesterone in blood in Chilean newborns: antecedents for implementing a grogram for the neonatal detection of congenital adrenal hyperplasia].

Background: The early diagnosis and therapy of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency can prevent adrenal crises and erroneous gender assignment in affected newborns. To achieve this goal neonatal mass-screening programs have been developed, measuring blood 17 alpha-hydroxyprogesterone (17OHP). In Chile there is no experience with this type of screening.

[Excess of mineralocorticoids in essential hypertension: clinical-diagnostic approach].

Background: Primary hyperaldosteronism is more frequent among subjects with essential hypertension than previously thought. The prevalence, according to local and international evidence could fluctuate between 9 and 10%.

Aim: To investigate if subjects with essential hypertension have different aldosterone and renin plasma levels than normotensive subjects.

Mutations in the CYP21 B gene in a Chilean population with simple virilizing congenital adrenal hyperplasia.

Steroid 21-hydroxylase deficiency (21OHD) compromises about 95% of all cases of congenital adrenal hyperplasia. We have characterized the disease-causing mutations in the steroid 21-hydroxylase genes of 19 Chilean patients (12 females and 7 males) with the simple virilizing (SV) form of 21OHD and compared them with other SV-populations. Using allele-specific polymerase chain reaction, we identified lesions in 28 chromosomes out of 38 tested (73.

Primary hyperaldosteronism in essential hypertensives: prevalence, biochemical profile, and molecular biology.

There is evidence that primary aldosteronism (PA) may be common in patients with essential hypertension (EH) when determinations of serum aldosterone (SA), plasma renin activity (PRA), and the SA/PRA ratio are used as screening. An inherited form of primary hyperaldosteronism is the glucocorticoid-remediable aldosteronism (GRA) caused by an unequal crossing over between the CYP11B1 and CYP11B2 genes that results in a chimeric gene, which has aldosterone synthase activity regulated by ACTH. The aim of this study was to evaluate the prevalence of PA and the GRA in 305 EH patients and 205 normotensive controls.

High prevalence of thyroid abnormalities in a Chilean psychiatric outpatient population.

The aim of the present study was to establish the prevalence of thyroid disturbances in patients consulting for panic and mood disorders. These data may be relevant because thyroid functional alterations affect the success of treatment in these pathologies. We studied prospectively 268 psychiatric outpatients (204 females and 64 males) diagnosed by DSM-IV criteria.

[High prevalence of undiagnosed primary hyperaldosteronism among patients with essential hypertension].

Background: Classically, primary hyperaldosteronism was diagnosed in no more than 1% of patients with hypertension, when hypokalemia was used as the screening test. However, numerous patients with primary hyperaldosteronism do not have hypokalemia and the disease remains undiagnosed.

Aim: To assess the prevalence of normokalemic primary hyperaldosteronism among patients classified as having essential hypertension.

[Detection of thyroglobulin autoantibodies and potential interference with serum thyroglobulin measurement].

Background: Thyroglobulin measurement is useful for the follow up of patients subjected to total thyroidectomy for differentiated thyroid carcinoma. Thyroglobulin autoantibodies may interfere with its determination.

Aim: To measure thyroglobulin autoantibodies and their interference with thyroglobulin determination.

[Capacity to predict a recurrence of lupus erythematosus using double-stranded anti-DNA antibodies and Farr technique].

Background: Patients with inactive systemic lupus erythematosus (SLE) and elevated high affinity double-stranded anti-DNA antibodies (anti-dsDNA), measured using Farr technique, would have a risk of relapse that fluctuates between 40 to 80% according to different series.

Aim: To study the association between anti-dsDNA levels measured using Farr technique and disease activity and their predictive capacity for relapses.

Material And Methods: Anti-dsDNA antibodies were measured according to Farr method in 60 healthy subjects, 69 patients with other connective tissue diseases and in 120 patients with SLE.

Salt-wasting congenital adrenal hyperplasia: detection of mutations in CYP21B gene in a Chilean population.

The steroid 21-hydroxylase deficiency (21OHD) is the most frequent cause of congenital adrenal hyperplasia. We have characterized the disease-causing mutations in the 21-hydroxylase genes of 63 patients with salt-wasting congenital adrenal hyperplasia from a Chilean population of Hispanic origin, a group that has been scarcely evaluated. Using allele-specific PCR, lesions were identified in 97 chromosomes out of 126 tested (77%).

[Measurement of low levels of plasma renin activity. A methodological improvement].

Background: The present method to measure plasma renin activity is cumbersome and imprecise, factors that limit its clinical application.

Aim: To assess the importance of blood sampling conditions and the usefulness of increasing incubation time to measure plasma renin activity at low levels.

Patients And Methods: Twenty hypertensive patients, 14 female, aged 14 to 76 years old, were studied.

[Molecular diagnosis of salt wasting congenital adrenal hyperplasia, caused by deficit of 21-hydroxylase, in the Chilean population].

Background: The most frequent cause of congenital adrenal hyperplasia, manifested as virilization and salt wasting, is the deficit of 21-hydroxylase. This disease is originated by mutations of the gene CYP21 that codifies this enzyme, mostly recombination between this gene and its inactive pseudogene called CYP21P.

Aim: To study the molecular origin of this enzyme deficiency in Chilean patients.

An alternative ELISA for T4 determination based on idiotype anti-idiotype interaction and a latex method for anti-idiotype monoclonal antibody selection.

This paper is the first report on the use of an idiotype-anti-idiotype monoclonal antibody reaction to develop an enzyme immunoassay for thyroxine (T4). We have developed a monoclonal antibody against T4, named 1F10 of IgG1 subclass and KA 5.21 x 10(8) M-1 which was used to obtain anti-idiotypic monoclonal antibodies.

[Breast cancer: comparison between biochemical and immunohistochemical determination of estrogen receptors].

Immunohistochemical (IH) assessment of nuclear estrogen receptor has been considered an alternative method to conventional biochemical assay. The present work intends to compare specificity and sensitivity of IH and biochemical technique to assess nuclear estrogen receptor in formalin-fixed and paraffin-embedded mammary carcinoma samples. IH positive reaction was defined as 14% or more nuclear staining in 100 cells counted under high magnification (400x).