1,721,012 research outputs found
Biomolecules and Cardiovascular Diseases in Women
Get PDF: Although cardiovascular diseases (CVD) are the leading cause of non-communicable diseases-dependent death worldwide, their effects are still largely underestimated in women [...]
Biological function and clinical relevance of chromogranin A and derived peptides
No full textChromogranin A (CgA) is the major soluble protein co-stored and co-released with catecholamines and can function as prohromone giving rise to several bioactive peptides. This review focuses on these molecules summarizing their physiological functions, their pathogenetic implications and their recent use as biomarkers in several pathological conditions. A thorough literature search of the electronic healthcare databases MEDLINE, from January 1985 to September 2013, was conducted to identify articles and studies concerned with CgA and its processing. The search strategies utilized key-words such Chromogranin A, Vasostatin-1 and 2, Chromofungin, Chromacin, Pancreastatin, Catestatin, WE-14, Chromostatin, GE-25, Parastatin and Serpinin, and was supplemented by the screening of references from included papers and review articles. A total of 209 English-language, peer-reviewed original articles or reviews were examined. The analysis of the retrospective literature suggested that CgA and its several bioactive fragments exert a broad spectrum of regulatory activities by influencing the endocrine, the cardiovascular and the immune systems and by affecting the glucose or calcium homeostasis. Since some peptides exert similar effects, but other elicit opposite responses, the regulation of the CgA processing is critical to maintain homeostasis, whereas an unbalanced production of peptides that exert opposing effects can have a pathogenetic role in several diseases. These clinical implications entail that CgA and its derived peptides are now used as diagnostic and prognostic markers or to monitor the response to pharmacological intervention not only in endocrine tumours, but also in cardiovascular, inflammatory and neuropsychiatric diseases
Energy balance and active lifestyle: potential mediators of health and quality of life perception in aging
No full textThe relationship between aging and perception of health and quality of life is complex and its mediation mechanisms need to be further explored. The purpose of this study was to investigate the mediating effects of total energy expenditure and intake, body mass, and body image dissatisfaction on the relationship between age and perception of health and quality of life. Forty-two senior athletes, 55 physically active, and 61 sedentary individuals (aged 55-84 years) were evaluated for total energy expenditure (EE), energy intake (EI), body mass index (BMI), absolute Body Dissatisfaction Index (BDIabx), and physical (PCS) and mental (MCS) health and quality of life perception. Multiple mediation analyses were applied to assess the relationship between age and PCS and MCS indices, through the mediators EE, EI, BMI, and BDIabx. For MCS, but not for PSC, the mediation analysis showed: (a) a direct effect of age; (b) a mediation path through EE, EI, BMI, and BDIabx; and (c) a positive total effect. The combination of positive and negative mediating effects influencing the mental health perception underlined that with advancing age, the maintenance of high levels of energy expenditure through physical activity could positively impact body image satisfaction and, in turn, mental health
How older adults cope with motor-cognitive complexity during dual task walking: the role of executive function involvement
No full textThis cross-sectional study investigated the interactive dual-task (DT) effects of executive function demands and environmental constraints on older adults' walking and the moderating role of habitual physical activity (PA). Locomotor performance under different environmental constraints (flat versus obstructed walking) and cognitive performance with different executive function involvement (backward counting versus random number generation) were assessed under single-task (ST) and DT conditions in 135 participants (mean age 68.1 ± 8.4). The weekly number of daily steps was measured. Reciprocal DT effects of walking on cognitive performance and of the cognitive task on gait performance were computed and submitted to analyses of covariance with age, PA level, and cognitive functioning as covariates, followed by linear regressions with PA level as predictor. Cognitive task demands and environmental constraints individually and jointly affected gait variability (p = 0.033, ηp2 = 0.08) and executive function performance (p = 0.009, ηp2 = 0.09). Physical activity level predicted a low but significant percentage of variance of DT effects on gait only in flat walking (R2 = 0.04, p = 0.027). Results suggest that older individuals may adopt variable task prioritization in dual tasking depending on the type of executive function involvement and the environmental constraints on walking. Their DT ability was slightly affected by habitual PA
Steps to health in cognitive aging: effects of physical activity on spatial attention and executive control in the elderly
No full textThe purpose of this study was to investigate whether physical activity (PA) habits may positively impact performance of the orienting and executive control networks in community-dwelling aging individuals and diabetics, who are at risk of cognitive dysfunction. To this aim, we tested cross-sectionally whether age, ranging from late middle-age to old adulthood, and PA level independently or interactively predict different facets of the attentional performance. Hundred and thirty female and male individuals and 22 adults with type 2 diabetes aged 55-84 years were recruited and their daily PA (steps) was objectively measured by means of armband monitors. Participants performed a multifunctional attentional go/no-go reaction time (RT) task in which spatial attention was cued by means of informative direct cues of different sizes followed by compound stimuli with local and global target features. The performance efficiency of the orienting networks was estimated by computing RT differences between validly and invalidly cued trials, that of the executive control networks by computing local switch costs that are RT differences between switch and non-switch trials in mixed blocks of global and local target trials. In regression analyses performed on the data of non-diabetic elderlies, overall RTs and orienting effects resulted jointly predicted by age and steps. Age predicted overall RTs in low-active individuals, but orienting effects and response errors in high-active individuals. Switch costs were predicted by age only, with larger costs at older age. In the analysis conducted with the 22 diabetics and 22 matched non-diabetic elderlies, diabetic status and daily steps predicted longer and shorter RTs, respectively. Results suggest that high PA levels exert beneficial, but differentiated effects on processing speed and attentional networks performance in aging individuals that partially counteract the detrimental effects of advancing age and diabetic status. In conclusion, adequate levels of overall PA may positively impinge on brain efficiency and attentional control and should be therefore promoted by actions that support lifelong PA participation and impact the built environment to render it more conducive to PA
Autonomic stress response and perceived effort jointly inform on dual tasking in aging
No full textThe study investigated, through neuroendocrinological, subjective and behavioral assessments, how aging individuals cope with locomotor-cognitive dual-tasking and whether physical activity habits influence the acute response to locomotor-cognitive performance. Seventy-nine healthy participants aged 55-85 years were assessed on locomotor (gait speed, stride length) and cognitive (working memory) performances under single- and dual-task (ST, DT) conditions, and habitual physical activity (daily steps). Rating of perceived exertion (RPE) was assessed immediately after performance. Salivary α-amylase (sAA) was measured prior, immediately and 5 min after performance. Gait and working memory variables, the area under the curve of sAA (AUC) and DT-ST differences (DT effects) were computed. AUC was higher when the ST or DT performance involved a locomotor component and showed a pre-to-post increment after DT only, whereas RPE was higher when performance involved a cognitive component. Daily steps neither predicted sAA, nor RPE. Associations between DT effects on sAA, RPE and performance emerged in high-active participants only. In aging individuals, DT walking elicits an autonomic stress response presumably led by the challenge to share resources relying upon common neural substrates. This autonomic response seems tuned to gait performance and subjective evaluation of effort in those more accustomed to walking
Betaine Treatment Prevents TNF-α-Mediated Muscle Atrophy by Restoring Total Protein Synthesis Rate and Morphology in Cultured Myotubes
No full textSkeletal muscle atrophy is represented by a dramatic decrease in muscle mass, and it is related to a lower life expectancy. Among the different causes, chronic inflammation and cancer promote protein loss through the effect of inflammatory cytokines, leading to muscle shrinkage. Thus, the availability of safe methods to counteract inflammation-derived atrophy is of high interest. Betaine is a methyl derivate of glycine and it is an important methyl group donor in transmethylation. Recently, some studies found that betaine could promote muscle growth, and it is also involved in anti-inflammatory mechanisms. Our hypothesis was that betaine would be able to prevent tumor necrosis factor-alpha (TNF-alpha)-mediated muscle atrophy in vitro. We treated differentiated C2C12 myotubes for 72 hr with either TNF-alpha, betaine, or a combination of them. After the treatment, we analyzed total protein synthesis, gene expression, and myotube morphology. Betaine treatment blunted the decrease in muscle protein synthesis rate exerted by TNF-alpha, and upregulated Mhy1 gene expression in both control and myotube treated with TNF-alpha. In addition, morphological analysis revealed that myotubes treated with both betaine and TNF-alpha did not show morphological features of TNF-alpha-mediated atrophy. We demonstrated that in vitro betaine supplementation counteracts the muscle atrophy led by inflammatory cytokines
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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