The Chilean socio-ethno-genomic cline.

Studies of the current Chilean population performed using classical genetic markers have established that the Chilean population originated primarily from the admixture of European people, particularly Spaniards, and Amerindians. A socioeconomic-ethno-genetic cline was established soon after the conquest. Spaniards born in Spain or Chile occupied the highest Socioeconomic Strata, while Amerindians belonged to the lowest. The intermediate strata consisted of people with different degrees of ethnic admixture; the larger the European admixture, the higher the Socioeconomic Level. The present study of molecular genomic markers sought to calculate the percentage of Amerindian admixture and revealed a finer distribution of this cline, as well as differences between two Amerindian groups: Aymara and Mapuche. The use of two socioeconomic classifications - Class and Socioeconomic Level - reveals important differences. Furthermore, Self-reported Ethnicity (self-assignment to an ethnic group) and Self-reported Ancestry (self-recognition of Amerindian ancestors) show variations and differing relationships between socioeconomic classifications and genomic Amerindian Admixture. These data constitute a valuable input for the formulation of public healthcare policy and show that the notions of Ethnicity, Socioeconomic Strata and Class should always be a consideration in policy development.

Leuprolide acetate gonadotrophin response patterns during female puberty.

OBJECTIVE: To assess normative data and the usefulness of spontaneous and LHRH analogue-stimulated serum LH and FSH levels measured by immunoradiometric assays (IRMA) in the evaluation of normal puberty. DESIGN: Prospective. Healthy girls in Tanner I and Tanner II from the local community were invited to participate (n = 47). METHODS: A leuprolide acetate test (500 mcg/m(2); sc) was performed. LH and FSH levels were determined using IRMA. Tanner II girls were assessed every 6 months until Tanner V. Girls who progressed from Tanner II to Tanner III in the next 6 months were called Tanner II-2; otherwise, they were called Tanner II-1. RESULTS: The prepubertal upper limit (CI 95%) was 0.49 IU/l for basal LH and 5.1 IU/l for stimulated LH. Taking into account these LH cut-off limits, 72.2% and 66.7% of Tanner II-1 and 41.6% and 41.7% of Tanner II-2 subjects presented overlapping values for basal and stimulated LH, respectively, as compared with the Tanner I group. The cut-offs for basal and stimulated LH to predict progression from Tanner II to Tanner III in the next 6 months were a basal LH level > or =0.49 IU/l (Sensitivity = 0.58; 1-Specificity = 0.33) and a poststimulated LH level > or =4.75 IU/l (Sensitivity = 0.67; 1-Specificity = 0.44). CONCLUSION: According to an IRMA, the basal and leuprolide acetate gonadotrophin response patterns during the beginning stages of puberty overlapped between Tanner I and Tanner II, and the cut-offs of basal and stimulated LH levels to predict progress from Tanner II to Tanner III had low sensitivities for the following 6 months.

Comparison of leptin levels, body composition and insulin sensitivity and secretion by OGTT in healthy, early pubertal girls born at either appropriate- or small-for-gestational age.

BACKGROUND: Small for gestational age (SGA) has been associated with decreased insulin sensitivity (IS). A possible mechanism is the postnatal development of a metabolically disadvantageous body composition (BC). AIM: To determine whether there are differences between IS and BC in girls in early puberty who were SGA (birth weight < 10th percentile) or appropriate for gestational age (AGA, 10th-90th percentile). METHODS: Age-matched (SGA/AGA) early pubertal girls (Tanner II) were recruited from local schools. We determined waist circumference (WC), the sum of four skinfolds (S4S), and per cent fat mass (fat %) by impedanciometry. Leptin and OGTT assays were performed. The insulinogenic index (I-In), HOMA-IR (homeostasis model assessment of insulin resistance) and WBISI (whole body insulin sensitivity) were calculated. RESULTS: Median age (interquartile range) for 30 SGA and 35 AGA girls was 10.2 (1.1) vs. 9.8 (0.9), respectively (P = NS). BMI percentiles were 62.6 (56) vs. 67.4 (39); WC 60.5 (9.5) vs. 62.2 (6.5) cm; S4S 52 (30) vs. 52.2 (29.5) cm, and fat %[26.2 (6.7) vs. 28.5 (6.3)] was similar in both groups. SGA girls had higher leptin levels [15.4 (9.7) vs. 9.6 (11) ng/ml; P = 0.01] and I-In [2.05 (1.86) vs. 1.47 (1.27) microU/ml* mg/dl; P = 0.02]. No differences between HOMA-IR [2.07 (1.26) vs. 2.04 (1.4)] and WBISI [5.3 (3.3) vs. 5.1 (3.1)] were found between groups. CONCLUSION: The higher leptin level and I-In in girls born SGA at the beginning of puberty may be early indicators of an underlying subtle degree of insulin resistance, despite similar BMI and BC to AGA girls.

Oxidative stress markers in plasma and urine of prepubertal patients with type 1 diabetes mellitus.

Markers of oxidative stress were studied in plasma and urine of prepubertal patients with type 1 diabetes mellitus (DM1) with less than 5 years of disease (n = 27). The results were compared to healthy, age- and sex-matched control children (n = 27). Oxidative stress parameters evaluated included advanced oxidation protein products (AOPP), total peroxyl radical-trapping antioxidant parameter (TRAP), and F2-isoprostanes (8-epi-prostaglandin-F2: 8-isoPGF2alpha). No statistically significant differences were found for any of the oxidative stress markers assessed between patients with DM1 and controls. In addition, weight, height, and routine metabolic tests, including creatininemia and cholesterol levels, were similar between the groups. The lack of significant differences between healthy controls and patients with DM1 suggests that treatment is able to counteract the increase in free radical production.

Comparison of clinical, ultrasonographic, and biochemical differences at the beginning of puberty in healthy girls born either small for gestational age or appropriate for gestational age: preliminary results.

CONTEXT: There are limited and controversial data concerning puberty characteristics in girls born small for gestational age (SGA). OBJECTIVE: The objective of the study was to document clinical, ultrasonographic, and biochemical characteristics at the beginning of puberty in matched healthy girls born either SGA or appropriate for gestational age (AGA) recruited from the community. PATIENTS: Inclusion criteria were breast Tanner stage II and a body mass index between the 10th and 95th percentiles. INTERVENTIONS: Recruited subjects underwent a complete physical exam, bone age, and ultrasound measurements of the internal genitalia. Hormonal assessment included fasting early morning dehydroepiandrosterone sulfate, androstenedione, SHBG, inhibin-B, FSH, LH, estradiol (E2), 17-hydroxyprogesterone (17OH Prog), and testosterone. Thereafter, a GnRH agonist test (leuprolide 500 microg, sc) was performed with FSH and LH at time 3 and 24 h for E2, 17OH Prog, and testosterone. RESULTS: Sixty-five girls (35 AGA, 30 SGA) with a mean age of 9.9 +/- 1.03 (7.8-12.5) yr, similar bone age/chronological age (1.02 +/- 0.8 in AGA and 1 +/- 0.76 in SGA), median height of 1.35 +/- 0.06 cm, and similar waist to hip ratio were included. No differences in the presence of pubic hair, axillary hair, apocrine odor, or ultrasound measurements were found. SGA girls had increased baseline E2 as well as stimulated E2 and 17OH Prog. CONCLUSIONS: In a preliminary sample of lean, healthy girls recruited from the community born either SGA or AGA, we observed slight hormonal differences at the beginning of puberty. Longitudinal follow-up of this cohort will allow us to understand whether these differences are maintained and have a clinical impact in their pubertal development.

[Autoantibodies against advanced glycation products in patients with type 1 diabetes mellitus]. / Autoanticuerpos dirigidos contra productos de glicación avanzada en pacientes con diabetes mellitus tipo 1.

BACKGROUND: Advanced glycation end products are associated with chronic complications of diabetes mellitus. This glycation process renders many proteins immunogenic. AIM: To detect the presence of antibodies against albumin, collagen and low density lipoprotein glycation products in boys and teenagers with diabetes mellitus. PATIENTS AND METHODS: Thirty one patients with diabetes mellitus type I, aged 11 +/- 3.8 years and with a mean duration of disease of 3.7 +/- 2.7 years and 31 healthy controls aged 12.4 +/- 5.3 years were studied. Antibodies against glycation end products were detected by ELISA and results were expressed as a ratio of the optical density of the glycated protein/optical density of the native protein. RESULTS: Diabetic patients and healthy controls did not have antibodies against albumin glycation end products. Diabetics had higher levels of antibodies than controls for collagen glycation end products (2.6 +/- 0.4 and 1.8 +/- 0.2 respectively, p < 0.01) and low density lipoprotein glycation end products (3.07 +/- 0.92 and 2.2 +/- 0.72 respectively, p < 0.05). CONCLUSIONS: The biological role of these antibodies is not clear. They could be a depuration mechanism for glycation end products or contribute to chronic complications of diabetes mellitus.

Estudio de seroprevalencia humana y de reservorio para hanta virus en Bahía San Pedro, comuna de Purranque, Osorno, Chile, 1998 / Research about human seroprevalence and reservoir for hantavirus at Bahía de San Pedro, Purranque, Osorno, Chile, 1998

En Chile, a partir de 1995 se comenzaron a describir los primeros casos de Síndrome Pulmonar por Hantavirus (SPH). En Osorno, en mayo de 1998, se registró el primer caso en una paciente que falleció. Surgió la necesidad de realizar el primer estudio de seroprevalencia humana y los reservorios, en el sector cordillerano de la costa distante a 45 km de la ciudad de Purranque, provincia de Osorno, X Región. se muestró al 100 por ciento de la población mayor de 5 años residente del sector y además se dispusieron 1012 trampas para el estudio de roedores. Se utilizó la técnica de Elisa para IgM e IgG en el Laboratorio Virológico de la Universidad Austral de Chile y se enviaron muestras de tejidos de roedores al Instituto Malbrán (Argentina) para estudio de PCR. Se encontró una seroprevalencia humana de un 6,3 por ciento a IgG y de un 0,9 por ciento para IgM. En roedores el éxito de captura fue de un 3,1 por ciento con una positividad de un 3,2 por ciento, correspondiente a un Oligoryzomis Longicaudatus, infestado por Hantavirus, cepa Andes

[Prevalence of celiac disease in diabetic children and adolescents]. / Prevalencia de enfermedad celíaca en niños y adolescentes diabéticos.

BACKGROUND: Celiac disease is more common in patients with insulin dependent diabetes than in the general population. AIM: To detect celiac disease in diabetic children and adolescents. PATIENTS AND METHODS: IgA antigliadin, IgG antireticulin and IgG antiendomysium antibodies were measured in 67 diabetic children (35 female), aged between 4 and 18 years old. RESULTS: Only one male adolescent, aged 18 years old, without gastrointestinal symptoms, had a significant elevation of antireticulin and antiendomysium antibodies. His intestinal biopsy showed subtotal villous atrophy, consistent with celiac disease. CONCLUSIONS: The prevalence of celiac disease in these diabetic children is 1:67 (1.5%). Similar figures have been reported elsewhere.

[Persistent microalbuminuria in insulin-dependent diabetics and cardiovascular risk factors]. / Microalbuminuria persistente en diabéticos insulino dependientes y factores de riesgo cardiovascular.

A possible association of cardiovascular risk factors and early diabetic nephropathy was investigated in 32 patients. Microalbuminuria (radioimmunoassay), total and HDL cholesterol and triglycerides (enzymatic methods), glycosylated hemoglobin (colorimetric methods), Apo A1 and B (immunonephelometric) and LDL were measured. Microalbuminuria was present in 28% of patients. Compared to subjects with no microalbuminuria they had increased levels of cholesterol (200.2 +/- 13.5 (SE) vs 168.6 +/- 9.4 mg/dl, p < 0.025) and LDL cholesterol (171.9 +/- 14.1 vs 137.4 +/- 9.1 mg/dl, p < 0.025). Systolic blood pressure was also higher in patients with microalbuminuria (127.8 +/- 3.9 vs 114.5 +/- 2.8 mmHg, p < 0.01). Microalbuminuria was correlated to the level of diastolic blood pressure (r = 0.74, p < 0.025). Thus, persistent microalbuminuria in insulin dependent diabetic patients is associated to cardiovascular risk factors which may explain the increased cardiovascular morbidity and mortality in these patients.

Tinción CVS: una nueva técnica de tinción para el diagnóstico de trofozoítos y quistes de protozoos y huevos de helmintos intestinales / CVS staining: a new technique of staining for the diagnosis of trophozoites, protozoa cysts and intestinal helminth eggs

Se describe una nueva técnica de tinción rápida, para preparaciones húmedas de deposiciones empleadas en el diagnóstico de trofozoítos, quistes de protozoos, y huevos de helmintos intestinales. Es una tinción dicrómica realizada con los colorantes de cristal violeta y safranina. Es de bajo costo, se prepara con suero fisiológico,isotónica, y proporciona un debido contraste entre los elementos parasitarios y los restos fecales, facilitando además la observación de leucocitos. Puede ser utilizada para teñir elementos parasitarios en muestras de deposiciones fijadas con formol-salino y PAF. El rendimiento diagnóstico de la tinción CVS es similar al observado con la tinción de MIF y superior a la tinción de tionina principalmente en la pesquisa de huevos de helmintos