Search results for "AGEING"
showing 10 items of 609 documents
Comparison of ground reaction forces and antagonist muscle coactivation during stair walking with ageing
2006
Abstract Stair walking is a demanding task in old age. Ground reaction force (GRF) analysis, relative EMG activation, and muscular coactivation were performed during stair walking. The aim was to investigate the ageing effect on GRF distribution and muscle antagonist coactivation during stair walking, at varied speed. During ascending at maximal velocity old subjects demonstrated reduced GRF in all examined phases (range: 28–35%), whereas muscle coactivation only was elevated for the Entire stance phase (18.5%). GRF parameters during ascent and descent at freely chosen speed demonstrated differences between age groups (5–28%). Furthermore, muscle coactivation was elevated in old subjects (e…
Potential effects of age-associated oxidative stress on mammalian oocytes/embryos
1996
This bioessay aims to explain the different effects of maternal ageing and postovulatory oocyte ageing on mammalian oocytes/embryos under the scope of 'the oxygen radical-mitochondrial injury hypothesis of ageing'. This hypothesis assumes a key role in the senescent process of oxygen radical damage to mitochondrial DNA, proteins and lipids. It is proposed that a decrease in intracellular ATP concentrations and glutathione (GSH)/glutathione disulphide (GSSG) ratio together with a concomitant increase in cytosolic Ca2+ are major factors causing the observed detrimental effects of ageing on cytoskeletal fibres, fertilization and embryo development.
LPS-mediated production of pro/anti-inflammatory cytokines and eicosanoids in whole blood samples: Biological effects of +896A/G TLR4 polymorphism in…
2011
Toll-like receptors (TLRs) are the principal mediators of rapid microbial recognition: the lipopolysaccharide (LPS) receptor TLR4 seems to have a paradigmatic role. Single nucleotide polymorphisms (SNPs) in the TLR4 gene, such as +896A/G, known to attenuate receptor signaling, have been described. The +896A/G SNP is significantly less frequent in patients with myocardial infarction, Alzheimer's disease or prostate cancer, whereas it is overrepresented in centenarians. To clarify and confirm the biological effects of +896A/G SNP and its role in the pathophysiology of age-related diseases and longevity, we assessed the levels of IL-6, TNF-α, IL-10 and eicosanoids (LTB4 and PGE2) in LPS-stimul…
Role of TLR4 polymorphisms in inflammatory responses: implications for unsuccessful aging.
2007
The total burden of infection at various sites may affect the progression of atherosclerosis and Alzheimer's disease (AD), the risk being modulated by host genotype. The role of lipopolysaccharide (LPS) receptor TLR4 is paradigmatic. It initiates the innate immune response against gram-negative bacteria, and TLR4 single nucleotide polymorphisms (SNPs), such as +896A/G, known to attenuate receptor signaling, have been described. This SNP shows a significantly lower frequency in patients affected by myocardial infarction or AD. Thus, people genetically predisposed to developing lower inflammatory activity seem to have less chance of developing cardiovascular disease (CVD) or AD. In the presen…
The relationship between age and production of tumour necrosis factor-α in healthy volunteers and patients with chronic heart failure
2003
Ageing is associated with an altered immune response. Elevated plasma levels of tumour necrosis factor-alpha (TNF-alpha) are present in patients with advanced chronic heart failure (CHF). However, the relationship between age and the immune response in CHF is unknown.We investigated the relationship between age and the TNF-alpha generating capacity of lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMC) in nine healthy control subjects (mean age 51.6+/-3.6 years, age range 39-75 years) and 22 stable patients with CHF (mean age 68.3+/-1.5 years, age range 52-78 years, NYHA class 3.0+/-0.2). We also tested the TNF-alpha generating capacity of all control subjects and …
Analysis of Candidate Genes in Celiac Disease: A Tool to Identify Life-Threatening Associated Genes?
2006
The authors have recently reported that celiac patients show a proinflammatory cytokine genetic profile characterized by the contemporaneous presence of both the tumour necrosis factor-alpha-308A and the interferon-gamma +874T allele-positive genotypes. The same alleles are considered risk factors for aging associated disease, whereas an anti-inflammatory cytokine genotype profile might be associated with an extended life expectancy. This paper reports data on the 1249-1250InsACAA/Non-Ins transforming growth factor (TGF)-beta2, a multifunctional anti-inflammatory cytokine, polymorphism distribution in 88 celiac disease (CD) patients, 99 age- and sex-matched controls, and 2895-year-old healt…
Ageing, lifestyle modifications, and cardiovascular disease in developing countries.
2006
Developing countries face the double menace of still prevalent infectious diseases and increasing cardiovascular disease (CVD) with epidemic proportions in the near future, linked to demographic changes (expansion and ageing), and to urbanisation and lifestyle modifications. It is estimated that the elderly population will increase globally (over 80% during the next 25 years), with a large share of this rise in the developing world because of expanding populations. Increasing longevity prolongs the time exposure to risk factors, resulting in a greater probability of CVD. As a paradox, increased longevity due to improved social and economical conditions associated with lifestyle changes in t…
Comparison between Spanish young and elderly people evaluated using Rivermead Behavioural Memory Test
2010
The first objective of this work was to compare scores obtained in the daily memory function between young and elderly people, and to check whether there are differences between the groups for each of the profile scores obtained in the memory test. A second aim of this paper is to study the relationship between everyday memory and age, while controlling for gender and educational level. The total and profile scores obtained in the Rivermead Behavioural Memory Test were compared in a sample of 60 young and 120 elderly people from Valencia (Spain). Results showed significant differences between the two groups: those between 18 and 30 years obtained a higher average than those over 65. Once th…
Impairment of gamma/delta T lymphocytes in elderly: implications for immunosenescence
2004
Gamma/delta T lymphocytes cells recognize the antigen in a non-classical way and are considered the third branch of the immune system devoted to defend the integrity of the body. Ageing is characterized by an impairment of the main way of protection (the adaptive branch) but, successfully aged people show compensatory mechanisms of defense such as proneness to inflammation. Moreover, very old subjects show an increased number of NK cells. We have previously demonstrated that gamma delta T lymphocytes are reduced in elderly. In the present paper we have studied some characteristics of these cells to evaluate the possibility that these cells might balance the decreased action of the adaptive …
Changes in mechanical properties of human plantar flexor muscles in ageing
2003
Changes in contractile and elastic properties of human plantar flexor muscles in ageing, were investigated in 12 young (19-24 years, YG) and 11 old (61-74 year, OG) men. Maximal isometric and concentric voluntary torques, at several angular velocities, were measured to construct torque-angular velocity relationship. This led to the calculation of an index of maximal shorting velocity (VImax) at low torque. Two methods were then used to calculate musculotendinous (MT, quick-release movements) and musculoarticular (MA, sinusoidal perturbations) stiffness. In both cases, stiffness was linearly related to torque, leading to the calculation of a stiffness index (SI) as the slope of the stiffness…