Analysis of Y-chromosome STRs in Chile confirms an extensive introgression of European male lineages in urban populations.

We analyzed the Y chromosome haplotypes (Yfiler) of 978 non-related Chilean males grouped in five sampling regions (Iquique, Santiago de Chile, Concepción, Temuco and Punta Arenas) covering main geo-political regions. Overall, 803 different haplotypes and 688 singletons were observed. Molecular diversity was moderately lower than in other neighboring countries (e.g. Argentina); and AMOVA analysis on Y-STR haplotypes showed that among variation within Chile accounted for only 0.25% of the total variation. Punta Arenas, in the southern cone, showed the lowest haplotype diversity, and discrimination capacity, and also the highest matching probability of the five Chilean samples, probably reflecting its more marked geographic isolation compared to the other regions. Multidimensional scaling (MDS) analysis based on RST genetic distances suggested a close proximity of Chilean Y-chromosome profiles to European ones. Consistently, haplogroups inferred from Y-STR profiles revealed that the Native American component constituted only 8% of all the haplotypes, and this component ranged from 5% in the Centre of the country to 9-10% in the South and 13% in the North, which is in good agreement with the distribution of Native American communities in these regions. AMOVA computed on inferred haplogroups confirmed the very low among variation observed in Chilean populations. The present project provides the first Chilean dataset to the international Y-chromosome STR Haplotype Reference Database (YHRD) and it is also the first reference database for Y-chromosome forensic casework of the country.

Revealing latitudinal patterns of mitochondrial DNA diversity in Chileans.

The territory of Chile is particularly long and narrow, which combined with its mountainous terrain, makes it a unique scenario for human genetic studies. We obtained 995 control region mitochondrial DNA (mtDNA) sequences from Chileans representing populations living at different latitudes of the country from the North to the southernmost region. The majority of the mtDNA profiles are of Native American origin (∼88%). The remaining haplotypes are mostly of recent European origin (∼11%), and only a minor proportion is of recent African ancestry (∼1%). While these proportions are relatively uniform across the country, more structured patterns of diversity emerge when examining the variation from a phylogeographic perspective. For instance, haplogroup A2 reaches ∼9% in the North, and its frequency decreases gradually to ∼1% in the southernmost populations, while the frequency of haplogroup D (sub-haplogroups D1 and D4) follows the opposite pattern: 36% in the southernmost region, gradually decreasing to 21% in the North. Furthermore, there are remarkable signatures of founder effects in specific sub-clades of Native American (e.g. haplogroups D1j and D4p) and European (e.g. haplogroups T2b3 and K1a4a1a+195) ancestry. We conclude that the magnitude of the latitudinal differences observed in the patterns of mtDNA variation might be relevant in forensic casework.

A reference frequency database of 15 autosomal STRs in Chile.

We estimated the allele frequencies for the 15 autosomal STR loci included in the AmpFlSTR(®) Identifiler (Applied Biosystems, USA) in a sample of 986 unrelated non-Native American individuals collected at five different localities from Chile, namely, Iquique, Santiago, Concepción, Temuco and Punta Arenas. Frequency distributions and several forensic parameters were estimated at each recruitment site. In addition, analyses were carried out merging the data into five sample locations. No significant statistical differences could be detected between different regions in Chile. These data represent one of the very few studies performed on autosomal STRs in Chile and therefore provide a useful tool for forensic casework carried out in the country.

Association of obesity and eating in the absence of hunger among college students in a Mexican-USA border city.

Few studies have examined disinhibited eating behaviors in Mexico. However eating in the absence of hunger (EAH), defined as eating in response to the presence of palatable foods in the absence of physiological hunger, is one of the more frequently examined behaviors. The purpose of this study was to assess the association between obesity and EAH among college students in a large Mexican-USA border city. Two-hundred and one sophomore college students completed the EAH questionnaire (EAH-C). Weight and height were measured. To assess reproducibility a test-retest was conducted in a subset sample (n = 20). Test-retest correlations ranged from ρ = 0.44 to 0.86, p < 0.01. Data obtained from the EAH-C were subjected to a principal components analysis with a varimax rotation. The mean age of participants was 21.0 ± 2.0 years, 52 % were female. The prevalence of overweight and obesity was 29 and 14 % respectively. The internal validity was assessed by Cronbach's alph. Internal consistency for all subscales was: external eating (α = 0.83), negative affect (α = 0.92) and fatigue/boredom (α = 0.86). Principal component analysis generated four subscales for the EAH-C: external eating, negative affect, fatigue and boredom. Comparing normal weight students versus obese students, normal weight students (57.1%) had higher scores on boredom subscale than obese students (p < 0.008). Female students had higher scores in the negative affect subscale than the males (p < 0.001). We conclude that the EAH-C had internal consistent subscales with good convergent validity. In this study population we found no association between EAH and obesity.

Sugar-sweetened beverage intake before 6 years of age and weight or BMI status among older children; systematic review of prospective studies.

The purpose of this study was to conduct a systematic review of prospective studies that examined the association between sugar-sweetened beverage intake before 6y of age and later weight or BMI status among older children. An electronic literature search was conducted in the MEDLINE/PubMed, SciELO, and EBSCO databases of prospective studies published from 2001 to 2011. Seven studies were analyzed. The study population was from 72 to 10,904 children. Three studies showed a consistent association between SSB intake before 6 y of age and increased weight, BMI, or waist circumference later in childhood, one study showed a positive trend of consumption of SSB and childhood obesity and the OR for incidence of overweight by baseline beverage intake was 1.04, another study it was observed that an increase in total sugar intake and sugar from sweets and beverages in children 1-2 y of age and 7-9 y of age have a tendency to increase BMI, and two studies showed no association. In conclusion, although the trend of the reviews studies, indicate an association between sugar-sweetened beverage intake before 6 y of age and increased weight, BMI or waist circumference later in childhood, to date, the results are inconsistent, and the two studies with the higher number of children showed a positive association.

El propósito de este estudio fue realizar una revisión sistemática de estudios prospectivos para valorar la asociación entre la ingesta de bebidas endulzadas (BE) antes de los seis 2013s de edad y el peso y el IMC en niños mayores. Se realizó una búsqueda electrónica de la literatura en las bases de datos de MEDLINE/PubMed, SciELO, y EBSCO, de estudios prospectivos publicados de 2001 a 2011. Se analizaron siete estudios. La población de los estudios osciló entre 72 y 10,903 niños. Tres estudios demostraron una asociación consistente entre el consumo de BE antes de los seis 2013s y un aumento de peso, IMC o circunferencia de cintura en 2013s posteriores, un estudio presentó una tendencia positiva y el OR sobre la incidencia de sobrepeso basado en la ingesta basal de BE fue de 1.04. En otro estudio se observó una tendencia a aumentar el IMC con el mayor consumo de azúcar y de BE en niños de 1 a 2 2013s de edad y de 7 a 9 2013s y en dos estudios no se observó asociación. En conclusión, aunque la tendencia de los estudios revisados indican una asociación entre la ingesta antes de seis 2013s de BE y un aumento de peso, IMC o circunferencia de cintura a la fecha, los resultados son inconsistentes. En los dos estudios con mayor número de niños, la asociación es positiva.

Sugar-sweetened beverage intake before 6 years of age and weight or BMI status among older children; systematic review of prospective studies / Ingesta de bebidas azucaradas antes de los seis años y peso o IMC en los niños mayores; una revisión sistemática de estudios prospectivos

The purpose of this study was to conduct a systematic review of prospective studies that examined the association between sugar-sweetened beverage intake before 6y of age and later weight or BMI status among older children. An electronic literature search was conducted in the MEDLINE/PubMed, SciELO, and EBSCO databases of prospective studies published from 2001 to 2011. Seven studies were analyzed. The study population was from 72 to 10,904 children. Three studies showed a consistent association between SSB intake before 6 y of age and increased weight, BMI, or waist circumference later in childhood, one study showed a positive trend of consumption of SSB and childhood obesity and the OR for incidence of overweight by baseline beverage intake was 1.04, another study it was observed that an increase in total sugar intake and sugar from sweets and beverages in children 1-2 y of age and 7-9 y of age have a tendency to increase BMI, and two studies showed no association. In conclusion, although the trend of the reviews studies, indicate an association between sugar-sweetened beverage intake before 6 y of age and increased weight, BMI or waist circumference later in childhood, to date, the results are inconsistent, and the two studies with the higher number of children showed a positive association (AU)

El propósito de este estudio fue realizar una revisión sistemática de estudios prospectivos para valorar la asociación entre la ingesta de bebidas endulzadas (BE) antes de los seis años de edad y el peso y el IMC en niños mayores. Se realizó una búsqueda electrónica de la literatura en las bases de datos de MEDLINE/PubMed, SciELO, y EBSCO, de estudios prospectivos publicados de 2001 a 2011. Se analizaron siete estudios. La población de los estudios osciló entre 72 y 10,903 niños. Tres estudios demostraron una asociación consistente entre el consumo de BE antes de los seis años y un aumento de peso, IMC o circunferencia de cintura en años posteriores, un estudio presentó una tendencia positiva y el OR sobre la incidencia de sobrepeso basado en la ingesta basal de BE fue de 1.04. En otro estudio se observó una tendencia a aumentar el IMC con el mayor consumo de azúcar y de BE en niños de 1 a 2 años de edad y de 7 a 9 años y en dos estudios no se observó asociación. En conclusión, aunque la tendencia de los estudios revisados indican una asociación entre la ingesta antes de seis años de BE y un aumento de peso, IMC o circunferencia de cintura a la fecha, los resultados son inconsistentes. En los dos estudios con mayor número de niños, la asociación es positiva (AU)

The European lactase persistence genotype determines the lactase persistence state and correlates with gastrointestinal symptoms in the Hispanic and Amerindian Chilean population: a case-control and population-based study.

BACKGROUND: The lactase persistent (LP) or lactase non-persistent (LNP) state in European adults is genetically determined by a single nucleotide polymorphism (SNP) located 13.9 kb upstream of the lactase (LCT) gene, known as LCT C>T(-13910) (rs4988235). The LNP condition leads to an inability to digest the milk sugar lactose leading to gastrointestinal symptoms and can affect nutrient and calcium intake in certain populations. OBJECTIVES: The authors studied a group of 51 Chilean patients to assess whether this SNP influences the LP/LNP state in this population, and determined the prevalence of LCT C>T(-13910) genotypes in a representative sample of 216 Hispanics and 43 Amerindians with correlation to digestive symptoms. DESIGN: Case-control study done in Chilean patients with clinical suspicion of LNP that were assessed using clinical survey, hydrogen breath test (HBT) and SNP genotyping. The population sample of Hispanics and Amerindians was assessed by clinical survey and SNP genotyping. RESULTS: Of the 51 patients with clinical suspicion of LNP, 29 were HBT-positive. The CC genotype (LNP) was present in 89.7% of the patients with positive HBT and in only 4.7% of those with negative HBT. The prevalence of the CC genotype was 56.9% in the Hispanic population and 88.3% in Amerindians, and was associated with a higher self-reported clinical intolerance to ingestion of dairy products. CONCLUSION: The LP/LNP state is determined by the LCT C>T(-13910) variant in Chileans. This variant predicts digestive symptoms associated with the ingestion of lactose and is a good tool for the diagnosis of primary adult hypolactasia. The LCT T(-13910) allele is rare in the Amerindian population and is suggestive of European ancestry in this contemporary population.

Efficacy and safety of adefovir dipivoxil in kidney recipients, hemodialysis patients, and patients with renal insufficiency.

BACKGROUND: This study analyzes the biochemical, serological, and virological efficacy and the safety of adefovir dipivoxil in patients with renal disturbances. METHODS: Twelve patients with lamivudine-resistant hepatitis B virus (HBV) chronic infection were treated for a median time of 15 (3-19) months. The daily dosage was 10 mg initially and then adjusted according to renal function. RESULTS: Median (range) ALT values remained stable: 55 (13-117) and 37 (17-266) UI/L. After the 12th month, the median decline in serum HBV DNA was from 8.76 (6.3-9.7) to 2.97 (1.15-5.65) log10 Eq/ml (median decline of -5.5 log10). No virologic breakthrough was observed. One of the six HBeAg-positive patients lost HBe Ag but without HBe seroconversion; none had HBs Ag loss. There were no significant clinical and biochemical adverse effects. In the 11 nonhemodialysed patients, the creatinine clearance significantly improved from 70 (30-100) to 88 (38-125) ml/mn (P=0.01) and the mean serum creatinine levels increased only slightly from 114 (91-839) to 130 (81-561) micromol/ml (NS). Serum phosphorus remained stable. The urinary level of protein decreased from 0.16 (0.08-8.63) to 0.12 (0.01-0.74) g/day (NS). CONCLUSIONS: Adefovir dipivoxil is safe for the treatment of chronic hepatitis B in patients with varying degrees of renal dysfunction and lamivudine-resistant HBV and results in biochemical and virological efficacy similar to that reported in the general population.

Estado de portador de Staphylococcus aureus en pacientes diabéticos

Estudio bacteriológico realizado en pacientes diabéticos insulino dependientes y no insulino dependientes que asisten al Patronato contra la Diabetes, en el período comprendido de Junio a Julio de 1987. Las infecciones causadas por Staphylococcus aureus han constitutido una muy seria preocupación para médicos y epidemiologos, por la gravedad que representan especialmente para diabéticos; en quiens se ha demostrado que el estado del portador es fuente de infección frecuente representado riesgo de diseminación para ellos y otros pacientes. (1) En este trabajo se investigaron 120 pacientes diabéticos, pudiéndose establecer que la frecuencia del estado portador varía significativamente en relación a los datos que se tienen de la población en general, que la presencia de Staphylococcus a nivel nasal es mayor en frecuencia los pacientes diabéticos insulinos dependientes (Tipo I) que en no dependientes, además que el patrón de susceptibilidad a los antimicrobianos varió notablemente entre un grupo y otro, la resistencia a las penicilinas G y a la oxacilina es dos veces mayor en cepas aisladas en pacientes insulino dependientes