1,721,198 research outputs found
Stability of neuroactive amino acids in cerebrospinal fluid under various conditions of processing and storage.
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Biological variability of myoglobin in healthy elderly and younger subjects
No full textTo study the effect of age on serum myoglobin more clearly, the analytical, intra-individual and inter-individual components of variation were estimated from duplicate analyses of specimens collected from 18 healthy elderly subjects [ages 74-97 years; 9 men (EM)], and 14 healthy younger subjects [ages 25-31 years; 7 men (YM)] over a period of 6 weeks. The mean values (μg/L) were EM: 53.7; EW: 44.9; YM: 34.2; YW:24.8. Estimated analytical (CV(A)), intra- (CV(I)) and inter-individual (CV(G)) variations as CV% were: CV(A): 2.2. CV(I): EM: 13; EW: 9.9; YM: 12.4; YW: 9.6. CV(G): EM: 37.6; EW: 28; YM: 18.5; YW: 13.4. The data obtained were used to derive the desirable analytical goal for imprecision (i.e., ≤6.5% in EM; ≤4.9% in EW and ≤6.2% in YM; ≤4.8% in YW); inaccuracy (i.e., ≤9.9% in EM; ≤7.7 in EW and ≤5.5% in YM; ≤4.12% in YW); the change required for serial results to be significantly different (i.e., 36% in EM; 28% in EW and 34% in YM; 27.2% in YW), the numbers of specimen collections required to produce a more precise estimate of the homeostatic set point of an individual within 5% (i.e., 26 in EM; 16 in EW and 24 in YM; 15 in YW), and the index of individuality (i.e., 0.34 in EM; 0.35 in EW and 0.67 in YM; 0.71 in YW). This study shows that intra-individual biological variation of myoglobin in healthy elderly subjects is not different from that in young subjects. Inter-individual variation, instead, is greatly influenced by differences in age and sex. (C) 2000, Editrice Kurtis
Effects of DHA-phospholipids, melatonin and tryptophan supplementation on erythrocyte membrane physico-chemical properties in elderly patients suffering from mild cognitive impairment
No full textA randomized, double-blind placebo-controlled clinical trial was carried out to assess the efficacy of a docosahexenoic acid (DHA)-phospholipids, melatonin and tryptophan supplemented diet in improving the erythrocyte oxidative stress, membrane fluidity and membrane-bound enzyme activities of elderly subjects suffering from mild cognitive impairment (MCI). These subjects were randomly assigned to the supplement group (11 subjects, 9F and 2M; age 85.3±5.3y) or placebo group (14-matched subjects, 11F and 3M; 86.1±6.5). The duration of the treatment was 12weeks. The placebo group showed no significant changes in erythrocyte membrane composition and function. The erythrocyte membranes of the supplement group showed a significant increase in eicosapentenoic acid, docosapentenoic acid and DHA concentrations and a significant decrease in arachidonic acid, malondialdehyde and lipofuscin levels. These changes in membrane composition resulted in an increase in the unsaturation index, membrane fluidity and acetylcholine esterase activity. Moreover, a significant increase in the ratio between reduced and oxidized glutathione was observed in the erythrocyte of the supplement group. Although this study is a preliminary investigation, we believe these findings to be of great speculative and interpretative interest to better understand the complex and multi-factorial mechanisms behind the possible links between diets, their functional components and possible molecular processes that contribute to increasing the risk of developing MCI and Alzheimer'
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Oxidative state and lipid composition of plasma from overweight and moderately obese women
No full textObjective: To determine the oxidative balance and plasma fatty acid composition of overweight and obese women.
Design: Comparative, descriptive study on 60 overweight or obese (> 25 BMI> 33), normotensive, non-diabetic women and 60 age-matched lean healthy women (BMI< 25).
Measurements: Plasma lipid, hydroperoxide, and antioxidants levels, fatty acid composition and lipoproteins susceptibility to peroxidation.
Results: Compared to the lean control group, the patient group had higher lipoprotein susceptibility to peroxidation and higher peroxide levels. On the contrary, the polyunsaturated fatty acids, in particular the omega-3 species, and the antioxidants were lower in the patient group.
Conclusions: The present study shows that overweight and obese people have oxidative balance impairment. The higher susceptibility to peroxidation of lipoproteins is the probable molecular mechanism that promotes a reduction in high unsaturated (and in particular omega-3) fatty acids, as well as antioxidants in the plasma of the overweight and obese subjects
Adipose tissue and cytokines
No full textAdipose tissue is not simply a storage depot for excess energy intake, it is also able to produce and release several substances with local (autocrine) and systemic (endocrine) actions. An up-to-date review of our knowledge in this area is given here. Several of the compounds deriving from adipose tissue have been shown to play a role in obesity-related health complications. The production of cytokines, such as Tumor Necrosis Factor-alpha (TNF-alpha), IL-6, and leptin, is implicated in the development of several disorders. Insulin resistance is one of the most clinically significant
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