Publications (15) View all
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Article: Effect of physical fitness and endurance exercise on indirect biomarkers of growth hormone and insulin misuse: Immunoassay-based measurement in urine samples.
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ABSTRACT: Indirect biomarkers of recombinant human growth hormone (rhGH), insulin-like growth factor-I (IGF-I), insulin-like growth factor-II (IGF-II), insulin-like growth factor binding proteins (IGFBP-2 and IGFBP-3) and insulin (C-peptide) were measured together with urinary parameters of renal damage (beta(2)-microglobulin and proteinuria) by immunoassays, in house validated for the purpose, in 61 subjects (36 elite athletes, 18 recreational athletes and 7 sedentary individuals) with different levels of physical fitness and endurance exercise. Validation parameters were good for the evaluated assays, excluding a high inter-assay imprecision and inaccuracy of 24 and 26% obtained for GH assay. The range of concentrations found in urine samples under investigation was generally covered by the calibration curves of the studied immunoassays. However, for the samples below or above the calibration curve, opportune dilution or concentration were performed. Particularly, C-peptide samples had to be diluted 1:5 and beta(2)-microglobulin ones assayed using a triple sample volume, to fall within the calibration range. Urinary C-peptide was the only biomarker statistically higher in samples of elite athletes when compared to recreational athletes and sedentary individuals. Among elite athletes, tae-kwon-do athletes showed the highest IGF-II basal values while weightlifting athletes showed the lower IGF-I and IGFBP-3 basal values. The trend observed in weightlifters' basal samples was confirmed in their training samples: IGF-I, IGF-II, IGFBP-3 and beta(2)-microglobulin were lower in with respect to those from synchronised swimming. Over the training season, within athlete variability was observed for IGFBP-3 for weightlifting athletes. In the studied subjects, no direct associations were found between biomarkers of GH or insulin misuse and urinary parameters of renal damage, eventually due to high-workload endurance training. The variations observed in different biomarkers should be taken in consideration in the hypothesis of setting reference concentration ranges for doping detection.Journal of pharmaceutical and biomedical analysis 12/2010; 53(4):1003-10. · 2.45 Impact Factor -
Article: Dietary polyunsaturated fatty acids may increase plasma LDL-cholesterol and plasma cholesterol concentrations in carriers of an ABCG1 gene single nucleotide polymorphism: study in two Spanish populations.
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ABSTRACT: ABCG1 mediates cellular cholesterol transport, but there is very little known about the influence of ABCG1 polymorphisms on human plasma lipoprotein cholesterol concentrations or on the interactions of these polymorphisms with diet. Our objective was to investigate whether interactions between PUFA intake and ABCG1 polymorphisms modulate associations with plasma total cholesterol (TC), LDL- and HDL-cholesterol in two Spanish populations. We grounded our investigation on two general population-based studies: the Hortega study (population A) and the Pizarra study (population B). Participants included 1178 individuals (50.0% women, age range 21-85 years) and 763 individuals (66% women, age range 23-73 years) from populations A and B, respectively, without lipid lowering drugs. Subjects were genotyped for ABCG1 variants. Biochemical measurements were taken by standard procedures. Dietary intakes were estimated with a validated questionnaire. In population A, the A allele homozygotes of SNP rs4148102 had higher TC and LDLc concentrations in subjects on a high PUFA diet than did the carriers of the G allele (242.1 ± 38.9 vs. 198.0 ± 36.0mg/dL, p = 0.003, and 149.8 ± 37.9 vs. 111.4 ± 32.1mg/dL, p = 0.005, respectively), and significant gene-diet interactions were observed (p=0.020 and p = 0.013, respectively). In population B, similar differences in TC and LDLc concentrations were also found in association with this SNP under a high PUFA diet (253.2±24.9 vs. 197.7 ± 39.9 mg/dL, p = 0.009, and 171.8 ± 20.5 vs. 120.4 ± 34.2mg/dL, p = 0.004, respectively), but the gene-diet interactions observed were not significant (p = 0.379 and p = 0.422, respectively). In the pooled populations, differences in the TC and LDLc concentrations increased (246.8 ± 32.9 vs. 198.0 ± 37.5, p = 6 × 10(-5), and 159.0±32.6 vs. 114.3 ± 33.1, p = 3 × 10(-5), respectively), and significant gene-diet interactions were maintained (p = 0.006 and p = 0.003, respectively). In two Spanish populations, the ABCG1 polymorphism rs4148102 was associated with variations in plasma lipoprotein cholesterol concentrations in subjects with high PUFA intakes. Carriers of the AA genotype consuming high PUFA diet showed higher plasma LDLc concentrations.Atherosclerosis 12/2011; 219(2):900-6. · 3.79 Impact Factor -
Article: Association of selected ABC gene family single nucleotide polymorphisms with postprandial lipoproteins: results from the population-based Hortega study.
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ABSTRACT: The aim of the study was to determine the influence of twenty single nucleotide polymorphisms (SNPs) of the ABCA1, ABCG1, ABCG5 and ABCG8 genes on the plasmatic concentrations of total cholesterol (TC), HDL and LDL cholesterol (HDLc, LDLc) in the postprandial state with a representative Spanish Caucasian population (1473 individuals, 50.0% women, ages ranging 21-85 years). In men, subjects with the AA genotype of the ABCA1 rs2230806 (R219K) polymorphism were associated with increased plasma LDLc levels, while the ABCA1 haplotype, which included the rs2230806 A allele, was associated with higher TC and LDLc plasma concentrations. In women, significant relationships were found between rs1893590 polymorphisms (ABCG1 gene) and HDLc plasma concentrations (subjects with the AA genotype had lower HDLc levels). For the ABCG8 gene, the rs4148211 polymorphism was associated with higher plasma TC and LDLc concentrations in the total population. Moreover, an ABCG5-G8 haplotype, which included the rs6544718 T allele, was associated with higher HDLc plasma concentrations in women. In conclusion, different SNPs of the ABCA1, ABCG1 and ABCG5-ABCG8 genes were associated, some under gender-specific analysis, with variations in the plasma lipid levels under postprandial conditions in a representative Spanish population.Atherosclerosis 01/2010; 211(1):203-9. · 3.79 Impact Factor -
Article: Plasma buprenorphine concentrations after the application of a 70 microg/h transdermal patch in dogs. Preliminary report.
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ABSTRACT: The objective of the present study was to evaluate the plasma concentrations and pharmacokinetics of buprenorphine after transdermal application in dogs (n = 4). A 70 microg/h transdermal buprenorphine patch was applied to the ventral abdomen of four healthy beagles. Blood samples were collected through a preplaced jugular catheter before and at 1, 2, 4, 8, 12, 24, 36, 48 and every 6 h until 108 h after the patch application. Plasma buprenorphine concentrations were measured using a (125)I-labelled radioimmunoassay (RIA) assay. No adverse effects were observed in any of the dogs. Concentrations of buprenorphine were detected in plasma after the application of the transdermal buprenorphine patch on the four experimental animals. Buprenorphine plasma concentrations increased during the first 36 h and then remained in the 0.7-1.0 ng/mL range during the study period. A decrease in plasma buprenorphine concentration was not observed during the study. Although analgesia could not be demonstrated the present study shows the ability of buprenorphine transdermal delivery systems developed for human use to deliver measurable concetrations of buprenorphine in dogs.Journal of Veterinary Pharmacology and Therapeutics 10/2009; 32(5):503-5. · 1.18 Impact Factor -
Article: Evaluation of immunoassays for the measurement of insulin and C-peptide as indirect biomarkers of insulin misuse in sport: values in selected population of athletes.
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ABSTRACT: Insulin and C-peptide have been proposed as possible biomarkers of human insulin hormone misuse in sport. An extended intra- and inter-laboratory validation of commercially available immunoassays was performed. Enzyme Amplified Sensitivity Immunoassay (EASIA) assays (Human Insulin-EASIA and C-peptide EASIA kits from BioSource) were evaluated for insulin and C-peptide in serum. The intra- and inter-laboratory precision and accuracy values were good for the evaluated assays with maximum imprecision and inaccuracy of 16% and 23%, respectively, obtained just for one day C-peptide assay evaluation. The range of concentrations found in serum samples under investigation was always covered by the calibration curves of the studied immunoassays. However, a 19.7% of the samples felt below the estimated insulin limit of quantification. High concordance between laboratory results was obtained for insulin assay (intraclass correlation coefficient -ICC=0.857), whereas that for C-peptide was lower (ICC=0.539). Evaluated immunoassays were used to measure serum concentrations of insulin and C-peptide in elite athletes of various sport disciplines at different moment of training season, in recreational athletes at baseline conditions and finally in sedentary individuals. Serum insulin was statistically lower both in recreational and elite athletes when compared to sedentary individuals. Among elite athletes, the specific sport affected serum insulin (e.g., weightlifting) and C-peptide (e.g., triathlon) concentrations. Over the training season, a within athletes variability was observed for taekwondo, swimming and weightlifting athletes. Variations due to those aspects should be taken in careful consideration in the hypothesis of setting reference concentration ranges for doping detection.Journal of pharmaceutical and biomedical analysis 02/2009; 49(3):793-9. · 2.45 Impact Factor
