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.

Deletion of BCR region 3' in chronic myelogenous leukemia.

The t(9;22)(q34;q11) produces the BCR/ABL fusion gene which codifies a 210 kb protein with a strong tyrosine kinase activity and is involved in cellular development and growth. Because this translocation is a reciprocal event, it could give rise to a second fusion gene, ABL-BCR, on the derivative 9q+. We analyzed the influence of the 3' M-BCR deletion on the clinical picture at diagnosis and disease outcome in 57 patients with a clinical diagnosis of CML. Molecular studies were done on DNA from peripheral blood leukocytes or bone marrow with the restrictions enzymes BglII, EcoRI, HindIII, and BamHI, and the BCR 3' probe (transprobe 1) (Oncogene Science Inc.), which encompasses almost all of the 5.8 Kb of the M-BCR gene area. In 18 patients Southern blot analysis showed deletion of the 3' end of BCR gene (32.7%). There were no significant differences between patients with or without deletion, either in the clinical and laboratory data at the disease diagnosis or at the disease outcome. The absence of differences between the patients with and without 3' BCR deletion supports the hypothesis that the hybrid gene ABL-BCR does not have an important role in leukemogenesis in CML cases.

[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.

Identification of the Hb Lepore phenotype by HPLC.

BACKGROUND AND OBJECTIVE: Hb Lepore is a structurally abnormal hemoglobin in which the abnormal globin chain is a hybrid or fused globin chain (db). Three different Lepore hemoglobins have been identified, differing from each other in the point at which the db fusion occurs; Hb Lepore Hollandia (d22/b50), Hb Lepore Baltimore (d59/b86) and Hb Lepore Boston (d87/b116). In Spain only Hb Lepore Boston and Hb Lepore Baltimore have been identified. Hb Lepore is easily detected by electrophoretic and chromatographic studies, whereas the type of Hb Lepore is distinguished by chromatography of tryptic peptides of abnormal db chain. In this work, we show an easier chromatography technique for identifying the Hb Lepore phenotype. DESIGN AND METHODS: Thirteen different unrelated families (23 patients) from different parts of Spain were studied. The existence of Hb Lepore was diagnosed by standard methodology and quantified by ionic exchange HPLC. The globin chains were studied by reversed phase HPLC, which showed us the phenotype of Hb Lepore; this phenotype was corroborated by a gold standard test using molecular biology techniques. The statistical analysis was designed to determine the behavior of the quantitative (hematologic) variables using the independent variable (Hb Lepore Baltimore or Hb Lepore Boston) categorized by Student's t-test for independent groups. The distribution of the variable was established using theoretical models and the variance homogeneity hypothesis was tested. The validity of the hematologic data was estimated by creating a receiver operating characteristic (ROC) curve. RESULTS: In the study of globin chains by reversed phase HPLC, in 14 patients (8 families) three peaks were eluted; they corresponded to a, b and db globin chains. In these cases when DNA was studied by PCR followed by digestion with the restriction enzyme Pvu II, the phenotype of Hb Lepore was identified as being the Boston variant, whereas in the rest of patients (9 in total), the peak identified with hybrid chain globin (db) was not present and the molecular study showed that these patients were heterozygotes for Hb Lepore Baltimore. INTERPRETATION AND CONCLUSIONS: The study of globin chains by reversed phase HPLC is sufficient to know the phenotype of Hb Lepore and thus tedious techniques such as chromatography of tryptic digestion product of db abnormal chains are not essential, a particularly important consideration in those laboratories that do not have the possibility of carrying out molecular biology studies. Neverteheless, we should continue to use a gold standard molecular biology test in cases of prenatal diagnosis because this technique is the most exact and reproducible that we have.

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.

Autotransplantation of peripheral blood stem cells mobilized by G-CSF in hematological malignancies: evidence for rapid and long-term sustained hematopoietic reconstitution.

We assessed the ability of granulocyte colony-stimulating factor (G-CSF) to mobilize peripheral blood stem cells (PBSC), the efficacy of PBSC infusion in the rescue of hematopoiesis after high-dose chemotherapy in 22 adult patients with hematological malignancies, and the long-term quality of engraftment. Bolus subcutaneous injections of G-CSF (12 micrograms/kg/day) were administered for 6 days. A median of three leukaphereses resulted in the collection of a median of 5.45 X 10(8) mononuclear cells/kg, 4.52 X 10(6) CD34+ cells/kg, and 3.97 X 10(4) CFU-GM/kg. G-CSF (5 micrograms/kg daily) was administered after PBSC infusion until granulocyte recovery. The median time to attain a neutrophil level > 0.5 X 10(9)/L and a platelet count > 20 X 10(9)/ L was 11 days. The median follow-up in 17 survivors was 23.8 months. These patients have maintained a complete and stable graft and some of them with neoplastic recurrence tolerated further chemotherapy. These results confirm that mobilization of PBSC by G-CSF can be performed on an outpatient setting and used in heavily pretreated patients. G-CSF mobilized PBSC transplantation provides early and complete engraftment in most patients.

[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.

[Chromosomal changes in 60 patients with acute myeloblastic leukemia. Frequency, characteristics and prognostic significance]. / Alteraciones cromosómicas en 60 pacientes con leucemia aguda mieloblástica. Frecuencia, características y significado pronóstico.

Sixty patients diagnosed of acute myeloblastic leukaemia (AML) on whom a chromosomal study was performed at diagnosis were evaluated. Their median age was 43 years (range: 8-89). Normal karyotype was present in 59% of the cases, it being abnormal in the remaining 41%. Chromosomal alterations appeared in 64% of the patients with M-4 morphology, in 43% of M-5, 40% of those with M-1, 33% of the M-2, and in 14% of the cases with M-3 morphology. The two patients with M-6 had abnormal karyotype. No correlations could be established between normal or abnormal karyotype and the clinical or laboratory data. Structural alterations were commonest amongst the patients with abnormal karyotype. Such alterations included t(8; 21), t(9; 22); t(7; 22), del 11q23, inv 16 (p13;q22), plus multiple major abnormalities in the M-6 patients. A strikingly low incidence of t(15; 17) was found in the acute promyelocytic leukaemia cases. Two chromosomal alterations not previously reported in AML were found in this series, namely, inv 13 (p11;q32) and t(21;1) (q22;q22). The finding of an abnormal karyotype had no unfavourable influence on the complete remission (CR) rate, which reached 65% of the patients with normal karyotype and 81% of those with abnormal karyotype. No differences were found in the duration of CR in this connection (80 and 77 weeks, respectively). Despite the lack of definite prognostic significance, the study of the karyotype appears as an important information in the diagnosis of AML.

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