996 resultados para Serum Potassium


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In this study we sought to determine whether a Titin peptide fragment can serve as a clinical biomarker for changes in muscle mass.

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Drying and denaturation kinetics of aqueous droplets of α-lactalbumin (α-lac), β-lactoglobulin (β-lg), and bovine serum albumin (BSA) were measured in a convective drying environment. Single droplets having an initial droplet diameter of 2 ± 0.1 mm and containing 10% (w/v) protein concentration were dried using conditioned air (65 and 80 °C, 2-3% RH, 0.5 m/s velocity) for 600 s. The denaturation of these proteins was measured by using reversed-phase HPLC. At the end of 600 s of drying 13.3 and 19.4% α-lac was found to be lost due to denaturation at 65 and 80 °C, respectively. Up to 31.0% of β-lg was found to be denatured, whereas BSA was not found to be significantly (p > 0.05) denatured in these drying conditions. The formation and strength of skin and the associated morphological features were found to be linked with the degree of denaturation of these proteins. The secondary structure of these proteins was significantly (p < 0.05) affected and altered by the drying stresses. The β-sheet and random coil contents were increased in α-lac by 6.5 and 4.0%, respectively, whereas the α-helix and β-turn contents decreased by 5.5 and 5.0%, respectively. The β-sheet and random coil contents in β-lg were increased by 7.5 and 2.0%, respectively, whereas the α-helix and β-turn contents decreased by 3.5 and 6.0%, respectively. In the case of BSA the β-sheet, α-helix, and random coil contents were found to increase, whereas the β-turn content decreased.

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Leptin and ghrelin have been implicated in the pathogenesis of major depression. However, evidence is lacking among apparently healthy people. This study examined the relationship of these appetite hormones to depressive symptoms in a Japanese working population.

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There is evidence that major psychiatric discords such as schizophrenia (SZ) and bipolar disorder (BD) are associated with dysregulation of synaptic plasticity with downstream alterations of neurotrophins. Brain-derived neurotrophic factor (BDNF) is the most widely distributed neurotrophin in the central nervous system (CNS), and performs many biological functions such as promoting the survival, differentiation, and plasticity of neurons. Variants in the BDNF gene increase the risk of SZ and bipolar disorder. Chronic administration of drugs used to treat SZ and BD, such as lithium, valproate, quetiapine, clozapine, and olanzapine, increases BDNF expression in rat brain. To examine serum BDNF, three groups of chronically medicated DSM-IV SZ patients, on treatment with clozapine (n=27), typical (n=14), and other atypical antipsychotics (n=19), 30 euthymic BD patients, and 26 healthy control had 5 ml blood samples collected by venipuncture. Serum BDNF levels were significantly higher in SZ patients (p<0.001) when compared to either controls or euthymic BD patients. Increased BDNF in SZ patients might be related to the course of illness or to treatment variables. Prospective studies are warranted.

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BACKGROUND: Bipolar disorder (BD) is commonly comorbid with many medical disorders including atopy, and appears characterized by progressive social, neurobiological, and functional impairment associated with increasing number of episodes and illness duration. Early and late stages of BD may present different biological features and may therefore require different treatment strategies. Consequently, the aim of this study was to evaluate serum levels of eotaxin/CCL11, eotaxin-2/CCL24, IL-2, IL-4, IL-6, IL-10, IL-17, TNF-α, IFNγ, BDNF, TBARS, carbonyl, and GPx in a sample of euthymic patients with BD at early and late stages compared to controls. METHODS: Early-stage BD patients, 12 late-stage patients, and 25 controls matched for sex and age were selected. 10mL of peripheral blood was drawn from all subjects by venipuncture. Serum levels of BDNF, TBARS, carbonyl content, glutathione-peroxidase activity (GPx), cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, TNF-α and IFNγ), and chemokines (eotaxin/CCL11 and eotaxin-2/CCL24) were measured. RESULTS: There were no demographic differences between patients and controls. No significant differences were found for any of the biomarkers, except chemokine eotaxin/CCL11, whose serum levels were higher in late-stage patients with BD when compared to controls (p=0.022; Mann-Whitney U test). LIMITATIONS: Small number of subjects and use of medication may have influenced in our results. CONCLUSION: The present study suggests a link between biomarkers of atopy and eosinophil function and bipolar disorder. These findings are also in line with progressive biological changes partially mediated by inflammatory imbalance, a process referred to as neuroprogression.

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OBJECTIVES: There is ongoing debate regarding the optimal serum concentrations of 25-hydroxy-vitamin D for musculoskeletal health, including osteoarthritis (OA). The aim of this prospective cohort study was to determine whether serum 25-hydroxy-vitamin D concentrations were associated with the risk of hip arthroplasty for OA. DESIGN: This study examined 9135 participants from the Australian Diabetes, Obesity and Lifestyle Study who had serum 25-hydroxy-vitamin D measured in 1999-2000 and were aged ≥40 years at the commencement of arthroplasty data collection. The incidence of hip arthroplasty for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry. RESULTS: Over an average 9.1 (standard deviation (SD) 2.7) years of follow-up, 201 hip arthroplasties for OA were identified (males n = 90; females n = 111). In males, a one-standard-deviation increase in 25-hydroxy-vitamin D was associated with a 25% increased incidence (HR 1.25, 95% CI 1.02-1.56), with a dose response relationship evident by quartiles of 25-hydroxy-vitamin D concentration (P for trend 0.04). These results were independent of age, body mass index (BMI), ethnicity, smoking status, physical activity, season of blood collection, latitude, hypertension and diabetes, area level disadvantage or after excluding those with extreme low 25-hydroxy-vitamin D concentrations. No significant association was observed in women (HR 1.10, 95% CI 0.87, 1.39). CONCLUSIONS: Increasing serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip arthroplasty for OA in males, while no significant association was observed in females. The mechanism for the association warrants further investigation.

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Widely known for its recreational use, the cannabis plant also has the potential to act as an antibacterial agent in the medicinal field. The analysis of cannabis plants/products in both pharmacological and forensic studies often requires the separation of compounds of interest and/or accurate identification of the whole cannabinoid profile. In order to provide a complete separation and detection of cannabinoids, a new two-dimensional liquid chromatography method has been developed using acidic potassium permanganate chemiluminescence detection, which has been shown to be selective for cannabinoids. This was carried out using a Luna 100 Å CN column and a Poroshell 120 EC-C18 column in the first and second dimensions, respectively. The method has utilized a large amount of the available separation space with a spreading angle of 48.4° and a correlation of 0.66 allowing the determination of more than 120 constituents and mass spectral identification of ten cannabinoids in a single analytical run. The method has the potential to improve research involved in the characterization of sensitive, complex matrices.

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The impact of effective exercise against bone loss during experimental bed rest appears to be associated with increases in bone formation rather than reductions of bone resorption. Sclerostin and dickkopf-1 are important inhibitors of osteoblast activity. We hypothesized that exercise in bed rest would prevent increases in sclerostin and dickkopf-1. Twenty-four male subjects performed resistive vibration exercise (RVE; n = 7), resistive exercise only (RE; n = 8), or no exercise (control n = 9) during 60 days of bed rest (2nd Berlin BedRest Study). We measured serum levels of BAP, CTX-I, iPTH, calcium, sclerostin, and dickkopf-1 at 16 time-points during and up to 1 year after bed rest. In inactive control, after an initial increase in both BAP and CTX-I, sclerostin increased. BAP then returned to baseline levels, and CTX-I continued to increase. In RVE and RE, BAP increased more than control in bed rest (p ≤ 0.029). Increases of CTX-I in RE and RVE did not differ significantly to inactive control. RE may have attenuated increases in sclerostin and dickkopf-1, but this was not statistically significant. In RVE there was no evidence for any impact on sclerostin and dickkopf-1 changes. Long-term recovery of bone was also measured and 6-24 months after bed rest, and proximal femur bone mineral content was still greater in RVE than control (p = 0.01). The results, while showing that exercise against bone loss in experimental bed rest results in greater bone formation, could not provide evidence that exercise impeded the rise in serum sclerostin and dickkopf-1 levels.

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 A green method for the deoxygenation of graphene oxide (GO) was developed using K2CO3 as a reusable reduction agent. The size and thickness of the reduced GO are less than 1 μm and around 0.85 nm, respectively. Carbon dioxide is the only byproduct during this process. The reduction mechanism of the graphene oxide includes two reduction steps. On the one hand, ionic oxygen generated from the electrochemical reaction between hydroxyl ions and oxygen in the presence of K2CO3 reacts with carbonyl groups attached to the GO layers at 50°C. On the other hand, ionic oxygen attacks hydroxyl and epoxide groups, which become carbonyl groups and then are converted to carbon dioxide by K2CO3 at 90°C. These oxygenous groups are finally converted to CO2 from graphene layers, leading to the formation of graphene sheets. Headspace solid-phase microextraction and gas chromatography-mass spectrometry detected the existence of n-dodecanal and 4-ethylbenzoic acid cyclopentyl ester during the reduction, suggesting that oxygen functional groups on the GO layers are not only aligned, but randomly dispersed in some areas based on the proposed mechanism.

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Neutron activation analysis and gamma-ray spectroscopy were used to determine the quantity of potassium and sodium in an ash sample of Tabebuia sp bombarded with thermal neutrons. These techniques, widely applied in nuclear physics, can be used in the context of wood science as an alternative for the usual physical chemistry methods applied in this area. The quantity of K and Na in an 8.60 +/- 0.10 mg of ash was determined as being 1.3 +/- 0.3 mg and 11.0 +/- 1.8 mu g, respectively. The ratio of Tabebuia sp converted into ash was also determined as 0.758 +/- 0.004%.