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Metabolic Properties (metabolic + property)
Selected AbstractsLipoprotein(a) levels in girls with premature adrenarcheJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2008Nesibe Andiran Aim: Elevated lipoprotein(a) (Lp(a)) level is a risk factor for cardiovasculary disease (CVD). Women with polycystic ovary syndrome (PCOS) have higher Lp(a) and risk for CVD than controls. The girls with premature adrenarche (PA) were shown to share similar hormonal/metabolic properties with PCOS. We compared Lp(a) levels in PA, with healthy and PCOS girls. Methods: In total, 25 PA, 20 controls and 10 girls with PCOS were evaluated. Lp(a), lipid profiles and insulin, glucose, free testosterone, dehydroepiandrosterone sulfate (DHEAS) and androstenedione levels were measured. A family history about CVD was obtained. Results: The mean age of girls with PA, at time of the study, was 10.04 ± 1.53, control 9.83 ± 1.58 and PCOS was 16.58 ± 1.46 years. The median (range) of Lp(a) levels were 22.5 (3.50,99.90), 9.6 (3.33,32.40) and 21.2 (5.89,85.65) mg/dL in PA, control and PCOS groups, respectively (P > 0.05). The median Lp(a)'s were 14.5 (3.50,87.00) and 24.30 (6.20,99.90) mg/dL, in prepubertal (Tanner 1) and pubertal PA girls (Tanner 2,5), respectively (P > 0.05). The median Lp(a) of prepubertal peers was 8.7 (3.33,21.17), while that of pubertal ones was 15.4 (4.72,32.40) mg/dL (P > 0.05). There was no difference between Lp(a) levels of pre-pubertal PA girls and their peers; however, significant difference was found in Lp(a) levels in pubertal stages of PA and healthy peers (P < 0.05). The positive family history of CVD was 60% in PA; 55% and 80% in the control and PCOS groups, respectively, with no statistical difference. Lp(a) level was correlated with DHEAS (r = 0.386, P = 0.008) and free testosterone (r = 0.337, P = 0.022) levels positively. There was no significant correlation between Lp(a) and body mass index, fasting insulin and fasting glucose/insulin ratio. Conclusions: Lipoprotein(a) levels in pubertal girls with PA differ significantly from healthy peers. However, to clarify whether the girls with PA have an additional risk for CVD with respect to Lp(a), further follow-up studies with larger number of patients are necessary. [source] Oral antidiabetic agents as cardiovascular drugsDIABETES OBESITY & METABOLISM, Issue 1 2007D. P. Macfarlane The increased risk of cardiovascular disease associated with type 2 diabetes is well documented. Lesser degrees of abnormal glucose metabolism including impaired fasting glycaemia and impaired glucose tolerance are also associated with increased cardiovascular risk. Studies showing improved cardiovascular outcomes with oral antidiabetic agents are limited, with the UKPDS demonstrating improved macrovascular outcomes only in a subgroup of obese patients with type 2 diabetes treated with metformin, and the heavily criticized STOP NIDDM trial showing a reduction in the number of cardiovascular events with the alpha glucosidase inhibitor acarbose. In recent years there has been an increase in the number of oral antidiabetic drugs available to treat the hyperglycaemia of diabetes. Some of these drugs have complex metabolic properties, additional to their antihyperglycaemic effect, improving endothelial function and markers of atherogenesis, with the potential to reduce cardiovascular morbidity and mortality, as supported by the recently published results of the PROACTIVE study. The results of further long-term cardiovascular outcome studies with these newer agents are awaited. [source] Influence of the metabolic properties of human cells on the kinetic of formation of the major benzo[a]pyrene DNA adductsJOURNAL OF APPLIED TOXICOLOGY, Issue 5 2008Caroline Marie Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants. Some of them, including benzo[a]pyrene (B[a]P), are tumorigenic due to their ability to generate DNA adducts. In order to define potential biomarkers of B[a]P exposure, the aim of the study was to identify the major stable DNA adducts in B[a]P-treated human cells. The role played by cellular metabolism on the nature and frequency of the DNA lesions was investigated using keratinocytes (HaCat) and actively metabolizing hepatocytes (HepG2) cell lines. Quantification of DNA damage was carried out by HPLC coupled to tandem mass spectrometry, a sensitive method making possible the selective detection of the different potential stable DNA adducts of B[a]P. These include two adducts of the 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) pathway and three adducts of the radical cation pathway. The results indicate that incubation of cells with B[a]P induces almost exclusively the formation of BPDE DNA adducts on purine bases. The amount of DNA adducts generated in hepatocytes was found to be two orders of magnitude higher than that measured in keratinocytes. Interestingly, the level of the DNA adducts produced in the cells incubated with (±)- anti -BPDE was similar in the two cell lines, indicating that the difference observed upon incubation with B[a]P could be attributed to different kinetics of B[a]P metabolism. The repair rate of BPDE DNA adducts was identical in the two cell lines with a half-life estimated to be around 20 h. These data support the use of the stable BPDE DNA adducts, as relevant biomarkers of exposure to B[a]P. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effects of Trans and Conjugated LC N-3 Polyunsaturated Fatty Acids on Lipid Composition and Abdominal Fat Weight in RatsJOURNAL OF FOOD SCIENCE, Issue 8 2008T. Okada ABSTRACT:,Trans and conjugated fatty acids may exhibit either beneficial or detrimental bioactive effects depending on their metabolic properties. This study was conducted to elucidate if isomerization and conjugation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) demonstrate more favorable bioactivity on lipid metabolism compared to unmodified EPA and DHA. The effects of dietary intake of trans and conjugated forms of EPA and DHA on lipid metabolism were evaluated in animal trials and compared to a control group fed soybean oil. None of the experimental diets showed significant differences from the control in terms of body weight; however, the white adipose tissue weight of rodents fed trans DHA, conjugated EPA (CEPA), and conjugated DHA (CDHA) was significantly lower than the control. Triacylglycerol levels in plasma were significantly decreased in groups fed trans DHA (17.2 mg/dL) and CDHA (31.9 mg/dL) relative to the control (51.3 mg/dL). The total cholesterol concentrations were significantly lower than the control (68.0 mg/dL) in all experimental groups (47.3 to 53.7 mg/dL) except CEPA (58.3 mg/dL). Fatty acid compositions of lipids extracted from rodent livers were influenced by the dietary fatty acid profiles, with all groups showing higher concentrations of stearic acid and lower levels of linoleic acid compared to the control. Rodents fed trans DHA did not have detectable levels of these fatty acid isomers in their livers, suggesting either quick metabolism or a difficulty with bio-absorption. [source] Brain regulation of food intake and appetite: molecules and networksJOURNAL OF INTERNAL MEDICINE, Issue 4 2005C. BROBERGER Abstract. In the clinic, obesity and anorexia constitute prevalent problems whose manifestations are encountered in virtually every field of medicine. However, as the command centre for regulating food intake and energy metabolism is located in the brain, the basic neuroscientist sees in the same disorders malfunctions of a model network for how integration of diverse sensory inputs leads to a coordinated behavioural, endocrine and autonomic response. The two approaches are not mutually exclusive; rather, much can be gained by combining both perspectives to understand the pathophysiology of over- and underweight. The present review summarizes recent advances in this field including the characterization of peripheral metabolic signals to the brain such as leptin, insulin, peptide YY, ghrelin and lipid mediators as well as the vagus nerve; signalling of the metabolic sensors in the brainstem and hypothalamus via, e.g. neuropeptide Y and melanocortin peptides; integration and coordination of brain-mediated responses to nutritional challenges; the organization of food intake in simple model organisms; the mechanisms underlying food reward and processing of the sensory and metabolic properties of food in the cerebral cortex; and the development of the central metabolic system, as well as its pathological regulation in cancer and infections. Finally, recent findings on the genetics of human obesity are summarized, as well as the potential for novel treatments of body weight disorders. [source] Methods for metabolic evaluation of prostate cancer cells using proton and 13C HR-MAS spectroscopy and [3- 13C] pyruvate as a metabolic substrateMAGNETIC RESONANCE IN MEDICINE, Issue 5 2009Yakir S. Levin Abstract Prostate cancer has been shown to undergo unique metabolic changes associated with neoplastic transformation, with associated changes in citrate, alanine, and lactate concentrations. 13C high resolution-magic angle spinning (HR-MAS) spectroscopy provides an opportunity to simultaneously investigate the metabolic pathways implicated in these changes by using 13C-labeled substrates as metabolic probes. In this work, a method to reproducibly interrogate metabolism in prostate cancer cells in primary culture was developed using HR-MAS spectroscopy. Optimization of cell culture protocols, labeling parameters, harvesting, storage, and transfer was performed. Using [3- 13C] pyruvate as a metabolic probe, 1H and 13C HR-MAS spectroscopy was used to quantify the net amount and fractional enrichment of several labeled metabolites that evolved in multiple cell samples from each of five different prostate cancers. Average enrichment across all cancers was 32.4 ± 5.4% for [3- 13C] alanine, 24.5 ± 5.4% for [4- 13C] glutamate, 9.1 ± 2.5% for [3- 13C] glutamate, 25.2 ± 5.7% for [3- 13C] aspartate, and 4.2 ± 1.0% for [3- 13C] lactate. Cell samples from the same parent population demonstrated reproducible fractional enrichments of alanine, glutamate, and aspartate to within 12%, 10%, and 10%, respectively. Furthermore, the cells produced a significant amount of [4- 13C] glutamate, which supports the bioenergetic theory for prostate cancer. These methods will allow further characterization of metabolic properties of prostate cancer cells in the future. Magn Reson Med, 2009. © 2009 Wiley-Liss, Inc. [source] Characteristic rat tissue accumulation of nobiletin, a chemopreventive polymethoxyflavonoid, in comparison with luteolinBIOFACTORS, Issue 3-4 2002Akira Murakami Abstract Nobiletin (NOB), a polymethoxyflavonoid, is an effective anti-inflammatory and chemopreventive phytochemical found in citrus fruits. We compared the absorption and metabolism characteristics of NOB with those of luteolin (LT) in male SD rats. Each flavonoid (67.1 ,mol/kg of body weight) was given separately by gastric intubation, and then concentrations were measured at 1, 4, and 24 hours after administration. In the digestive organs, NOB showed a notable tendency for localizing into the mucous membrane and muscularis from 1 to 4 hours, in contrast to LT, though both NOB and LT were completely excreted within 24 hours. Further, significant amounts of NOB were detected in the whole liver and kidney specimens, whereas LT accumulation was slight. Although serum concentrations of NOB from 1 to 4 hours were comparable to those of LT, urinary concentrations of LT were significantly higher from 4 to 24 hours. Following glucuronidase/sulfatase treatments of urinary materials, we detected 3 types of mono-demethylated NOB, including 3,-demethyl-NOB, and two di-demethylated types, as well as 3,-demethyl-NOB alone in serum samples using liquid chromatography-mass spectral analysis. Our results suggest that the metabolic properties of polymethoxyflavonoids are distinct from those of other general flavonoids, because of their wide distribution and accumulation in tissue. [source] Lower ability to oxidize lipids in adult patients with growth hormone (GH) deficiency: reversal under GH treatmentCLINICAL ENDOCRINOLOGY, Issue 4 2006F. Brandou Summary Background, The aim of the study was to characterize lipid oxidation at exercise in adults with growth hormone deficiency (GHD) and to evaluate the effect of 6 and 12 months of GH replacement therapy on substrate carbohydrate (CHO) and lipid utilization at exercise. Patients and measurements, Twenty-five patients with GHD and 40 matched controls participated in the study. Ten of the 25 GH-deficient patients were treated with recombinant GH for 12 months. Anthropometric measurements and exercise calorimetry were performed before and after treatment. Maximal fat oxidation and the crossover point [that is the percentage of the theoretical maximal power (Wmax th) where CHO become the predominant fuel used for oxidation] were determined. Results and conclusion, The GH-deficient patients exhibited a highly significant shift in the balance of substrate oxidation during exercise, towards a decrease in fat oxidation, and a shift towards lower intensities of the crossover (52 ± 5·5%vs. 72·6 ± 6·6% of Wmax th, P < 0·03) and maximal fat oxidation (131·04 ± 14 vs. 234·4 ± 30·1 mg/min, P < 0·03) in the GHD and control groups, respectively. However, GH treatment at 6 and 12 months partially reversed this defect, resulting in an increase (+83%, P < 0·001) in the maximal ability to oxidize fat during exercise. These findings are consistent with the hypothesis that a lack of GH reduces the ability to oxidize lipids during exercise and that GH treatment restores this muscular metabolic property. [source] | |||||||||||||