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Biomedical subjects

D Sepúlveda

Publications and source records attributed to D Sepúlveda.

8 recordsLinked to original sources
PubMed2006

[Analysis of oxidative stress in exhaled breath condensate from patients with severe pulmonary infections].

OBJECTIVE: Oxidative stress is an intrinsic part of the chain of events leading to inflammation of the airways caused by bacterial infection. The aim of this study was to determine whether analysis of exhaled breath condensate from patients with severe lung infections reveals changes in the redox state at the airway surface. PATIENTS AND METHODS: The study included a total of 48 subjects divided into 4 groups: individuals without respiratory disease (n=14), patients with multilobar pneumonia (n=13), patients who had chronic obstructive pulmonary disease with superinfection (n=14), and mechanically ventilated patients with severe pneumonia (n=7). A sample of exhaled breath condensate was obtained within the first 72 hours of hospital admission and the concentrations of nitrite, nitrate, 8-isoprostane, and myeloperoxidase (MPO) were determined. RESULTS: Significant differences in the concentrations of nitrite, 8-isoprostane, and MPO were observed between patients and individuals without respiratory disease but no differences were found between the 3 patient groups. The concentration of MPO was correlated with the concentrations of 8-isoprostane and nitrate, which were normalized to the nitrite concentration. CONCLUSIONS: Analysis of the concentrations of 8-isoprostane and MPO in exhaled breath condensate allows assessment of oxidative stress in the airways of patients with severe lung infections.

Adult↗
PubMed2004

DYS19 and DYS199 loci in a Chilean population of mixed ancestry.

The current Chilean population originated from admixture between aboriginal populations (Amerindians) and Spanish conquerors of European origin. Consequently, the unions that gave rise to the Chilean population were chiefly between Spanish males and aboriginal females, and not the converse. To test the hypothesis that the Y chromosome of the Chilean population is mainly of Spanish origin, while the other chromosomes are from mixed (European and aboriginal) origin, we studied the DYS19 and DYS199 loci in two samples. One sample was obtained from a high socioeconomic stratum, while a second sample was from a low stratum. We studied male blood donors (N = 187) from Santiago, the capital of the country. Subjects were typed for the autosomal ABO and Rh (locus D) blood groups, and for the Y-linked DYS19 and the DYS199 loci, reported as Y-chromosome haplotypes. The aboriginal admixture was estimated for each genetic marker. The percentage of aboriginal admixture was 38.17% for the ABO system and 31.28% for the Rh system in the low socioeconomic stratum and 19.22% and 22.5%, respectively, in the high stratum. Y-chromosome haplotype frequencies constructed from the DYS19 and DYS199 loci demonstrated that the main haplotypes were DYS19*14/DYS199 C, as is often the case with many European populations, and DYS19*13/DYS199 C. The aboriginal admixture from Y-haplotype frequencies was estimated to be 15.83% in the low socioeconomic stratum and 6.91% in the high stratum. These values are lower than the values found using autosomal genetic markers, and are consistent with the historical background of the population studied. This study highlights the population genetic consequences of the asymmetric pattern of genome admixture between two ancestral populations (European and Amerindian).

Chile↗
PubMed1997

Appendicular skeletal muscle mass: effects of age, gender, and ethnicity.

This study tested the hypothesis that skeletal muscle mass is reduced in elderly women and men after adjustment first for stature and body weight. The hypothesis was evaluated by estimating appendicular skeletal muscle mass with dual-energy X-ray absorptiometry in a healthy adult cohort. A second purpose was to test the hypothesis that whole body 40K counting-derived total body potassium (TBK) is a reliable indirect measure of skeletal muscle mass. The independent effects on both appendicular skeletal muscle and TBK of gender (n = 148 women and 136 men) and ethnicity (n = 152 African-Americans and 132 Caucasians) were also explored. Main findings were 1) for both appendicular skeletal muscle mass (total, leg, and arm) and TBK, age was an independent determinant after adjustment first by stepwise multiple regression for stature and weight (multiple regression model r2 = approximately 0.60); absolute decrease with greater age in men was almost double that in women; significantly larger absolute amounts were observed in men and African-Americans after adjustment first for stature, weight, and age; and >80% of within-gender or -ethnic group between-individual component variation was explained by stature, weight, age, gender, and ethnicity differences; and 2) most of between-individual TBK variation could be explained by total appendicular skeletal muscle (r2 = 0.865), whereas age, gender, and ethnicity were small but significant additional covariates (total r2 = 0.903). Our study supports the hypotheses that skeletal muscle is reduced in the elderly and that TBK provides a reasonable indirect assessment of skeletal muscle mass. These findings provide a foundation for investigating skeletal muscle mass in a wide range of health-related conditions.

Absorptiometry, Photon↗
PubMed1996

How useful is body mass index for comparison of body fatness across age, sex, and ethnic groups?

This study tested the hypothesis that body mass index (BMI) is representative of body fatness independent of age, sex, and ethnicity. Between 1986 and 1992, the authors studied a total of 202 black and 504 white men and women who resided in or near New York City, were ages 20-94 years, and had BMIs of 18-35 kg/m2. Total body fat, expressed as a percentage of body weight (BF%), was assessed using a four-compartment body composition model that does not rely on assumptions known to be age, sex, or ethnicity dependent. Statistically significant age dependencies were observed in the BF%-BMI relations in all four sex and ethnic groups (p values < 0.05-0.001) with older persons showing a higher BF% compared with younger persons with comparable BMIs. Statistically significant sex effects were also observed in BF%-BMI relations within each ethnic group (p values < 0.001) after controlling first for age. For an equivalent BMI, women have significantly greater amounts of total body fat than do men throughout the entire adult life span. Ethnicity did not significantly influence the BF%-BMI relation after controlling first for age and sex even though both black women and men had longer appendicular bone lengths relative to stature (p values < 0.001 and 0.02, respectively) compared with white women and men. Body mass index alone accounted for 25% of between-individual differences in body fat percentage for the 706 total subjects; adding age and sex as independent variables to the regression model increased the variance (r2) to 67%. These results suggest that BMI is age and sex dependent when used as an indicator of body fatness, but that it is ethnicity independent in black and white adults.

Adipose Tissue↗
PubMed1995

Low spinal and pelvic bone mineral density among individuals with Down syndrome.

The bone mineral density of 15 adults with Down syndrome was compared to 25 control subjects without Down syndrome. Bone mineral density was measured by dual x-ray absorptiometry with a Lunar DPX scanner. Arm, leg, pelvic, and spine bone mineral density was tested. Analysis of covariance was conducted for each variable; Down syndrome was the independent variable, and the covariates were height, lean body mass, fat mass, age, and gender. No significant group differences were found for arm or leg bone mineral density. Individuals with Down syndrome had significantly lower pelvic and spinal bone mineral density. Before adjustment for covariates, percentage difference between group means for spine was 14.5% and for pelvis, 11.6%. Adjusted percentage was 11.1% and 13.9%, respectively. Suggestions for further research were made.

Adult↗
PubMedDate not supplied

[Early stimulation: 10 years' experience].

Infancy psychomotor yield in lower socioeconomic levels can be damaged from the first year of life. This implies future consequences to individuals, family-and society. Early stimulation programs have demonstrated to improve psychomotor yield in the above mentioned children. In Temuco, Chile, in groups of children with different risks, that were incorporated to an early stimulation program, it has been seen that the lower the birth weight the greater the risk of future psychomotor deterioration, which is also true for children that survived neonatal meningitis. On the other hand, in children that presented hyperbilirubinemia, low Apgar scores and neonatal septicemia, no significant statistical differences in psychomotor development have been observed in comparison with those of similar birthweight but without these antecedents. In this study the Chilean Health Ministry's Evaluation and Psychomotor Stimulation Program is reviewed as to adapt it for children at greatest risk.

Child Development↗