Experimental gerontology
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Experimental gerontology · Oct 2014
Frailty and telomere length: cross-sectional analysis in 3537 older adults from the ESTHER cohort.
Both telomere length and frailty were observed to be associated with aging. Whether and to what extent telomere length is related to frailty is essentially unknown. In this cross-sectional analysis of baseline data of 3537 community-dwelling adults aged 50 to 75 years of a large German cohort study, we assessed the hypothesis that shorter telomere length might be a biological marker for frailty. ⋯ Mean FI value was similar across tertiles of the T/S ratio (0.24±0.14, 0.24±0.14 and 0.23±0.14, respectively (p=0.09)), and FI and the T/S ratio were uncorrelated in gender- and age-specific analyses. In conclusion, T/S ratio and frailty were unrelated in this large sample of older adults. T/S ratio may therefore not be a meaningful biological marker for frailty.
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Experimental gerontology · Oct 2014
Comparative StudyRepetitive transcranial magnetic stimulation (rTMS) influences spatial cognition and modulates hippocampal structural synaptic plasticity in aging mice.
Normal aging is characteristic with the gradual decline in cognitive function associated with the progressive reduction of structural and functional plasticity in the hippocampus. Repetitive transcranial magnetic stimulation (rTMS) has developed into a novel neurological and psychiatric tool that can be used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency rTMS (≤1Hz) affects synaptic plasticity in rats with vascular dementia (VaD), and it ameliorates the spatial cognitive ability in mice with Aβ1-42-mediated memory deficits, but there are little concerns about the effects of rTMS on normal aging related cognition and synaptic plasticity changes. ⋯ Conversely, high-intensity magnetic stimulation (150% average resting motor threshold intensity, 1Hz, HIMS) appeared to be detrimental, inducing thinning of PSDs, disordered synaptic structure, and a large number of lipofuscin accumulations, as well as reducing the number of synapses and downregulating BDNF-TrkB and synaptic proteins. Ultimately, HIMS further impaired the capacity for learning and memory. In conclusion, we infer that aging-induced cognitive deficits are closely associated with hippocampal structural synaptic plasticity, and low-frequency magnetic stimulation plays an important role in regulating cognitive behavior via changing structural synaptic plasticity, and BDNF signaling might participate in this event.
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Experimental gerontology · Oct 2014
Lower lean mass and higher percent fat mass in patients with Alzheimer's disease.
In this study we analyzed body composition in relation to cognitive and functional status, in a cross-sectional sample of patients with Alzheimer's disease (AD). Seventy individuals (27 men, 78.1±6.5years; 43 women, 80.4±5.6years) with mild-moderate stages of AD (clinical dementia ratings 1 and 2) were selected from the Alzheimer Center, SS. Trinità Hospital, ASL 8 of Cagliari (Italy). ⋯ In conclusion, patients with AD had lower lean tissue mass and higher percent fat mass than healthy elderly individuals. In women, this pattern was associated with cognitive and functional decline, as indicated by MMSE and ADL values. Specific BIVA showed to be a suitable technique in the elderly, that could enhance BMI and MNA information in the evaluation of nutritional status.
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Experimental gerontology · Oct 2014
Comparative StudyAge-associated changes in rat immune system: lessons learned from experimental autoimmune encephalomyelitis.
Aging is associated with the decline in immune response to infectious agents and tumors and increasing risk of autoimmunity, but the incidence of autoimmune diseases does not increase in the elderly. To elucidate the cellular and molecular mechanisms influencing clinical expression of autoimmunity in aged animals, the phenotypic and functional characteristics of mononuclear cells isolated from the spinal cords of 3-month-old (young) and 26-month-old (aged) Dark Agouti rats immunized to induce experimental autoimmune encephalomyelitis (EAE) - the model of multiple sclerosis, the most common autoimmune disease of the central nervous system, were examined. Aged rats were less susceptible to EAE induction, and the neurological and histological picture was milder in those rats which developed the clinically manifested disease. ⋯ Additionally, the increase in the proportion of autoregulatory IL-17+IL-10+ cells on the account of proinflammatory IL-17+IFN-γ+ cells within IL-17+ lymphocytes suggested their lower pathogenic capacity in aged rats. This most likely reflected alterations in the aged rat spinal cord cytokine milieu, which were mirrored in a diminished expression of IL-1β mRNA followed by an enhanced expression of IL-6 and TGF-β mRNA. Overall, the study points to age-related changes in T lymphocytes and other cells from the spinal cord infiltrate which could contribute to the decreased susceptibility of aged rats to the induction of EAE.
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Experimental gerontology · Jul 2014
The association between physical activity and reduced body fat lessens with age - results from a cross-sectional study in community-dwelling older adults.
The aim of this study was to describe the relationship between accelerometer-determined physical activity (PA) and adiposity in community-dwelling older adults. In addition, we were interested in comparing the extent of correlation between questionnaire and accelerometer determined PA. ⋯ Both the amount and intensity of PA, but not sedentary time, have an independent dose-response association with adiposity. The association is much stronger using objective assessment compared to questionnaire. The magnitude of these associations decrease with age suggesting that physical activity programmes may need to be modified with increasing age.