Aggio et al. Respond to “Lessons for Research on Cognitive Aging”

We thank Dr. Belsky (1) for his interest in our study (2), in which we investigated associations between physical activity and cognitive function in young people. He raises several important issues on the role of physical activity as a public health strategy in the prevention of cognitive decline. The issue of “neuroselection,” wherein individuals with better cognitive function are more likely to engage in healthy behaviors such as physical activity and refrain from unhealthy ones such as smoking, is a potential source of bias in observational studies. The alternative hypothesis is that of “neuroprotection,” in which engagement in healthy behaviors is likely to lead to enhanced cognitive development

Sedentary behaviour among elite professional footballers: Health and performance implications

Background: Elite athletes should have little concern about meeting recommended guidelines on physical activity. However, sedentary behaviour is considered a health risk independent of physical activity, and is recognised in public health guidelines advising against prolonged sedentary time. There has been very little research on athletes’ physical activity behaviour outside elite sport. Methods: Given health and performance links, we investigated in-season post-training activity levels in 28 elite professional footballers during the English Premiership season. Players volunteered to wear a triaxial wrist accelerometer for 1 week, removing it only for training and matches. In total, 25 players met the inclusion criteria for analysis. Players recorded on average 632.6 min wear time p/day during the post-training period (SD±52.9) for a mean of 3.8 days (SD±1.5). Results: On average, players recorded 76.2 min p/day (SD±28.8) of moderate or vigorous activity post-training. The majority (79%) of post-training time was spent in sedentary activities (500.6 min per day±59.0). Conclusions: Professional footballers are alarmingly sedentary in their leisure time, and comparatively more so than non-athletic groups of a similar age and older. This raises questions over optimum recovery and performance, as well as long-term health and cardiovascular risk. Worryingly, retirement from elite sport is likely to further imbalance activity and sedentary behaviour. Promoting regular periodic light to moderate leisure time activity could be beneficial. Further research and provision of education and support for players is required in this area

Correlations between the performance of older adults in conditional discrimination training and in a screening test for Alzheimer’s Disease

The prevalence of neurocognitive disorders has been rising and Alzheimer's Disease (AD) is the most common cause. Studies on conditional discrimination have contributed to understand the variables associated with the cognitive function. However, the relationship of such studies with cognitive impairment in older adults remains under-explored. This research aims to compare the performances of older adults during tasks involving conditional discrimination training with their performances on Addenbroke's Cognitive Examination, a widely used screening test for cognitive impairments. The sample was composed of 45 older adults. The participants performed a computerized task consisting on establishing arbitrary conditional relations between three pairs of stimuli. Addenbrooke's Cognitive Examination was administered to assess the cognitive performance. The analysis revealed a positive correlation between the performance in conditional discrimination and in the cognitive assessment. This correlation was observed only among participants who did not reported having AD in use of anti-cholinesterase drugs (30 participants). These findings demonstrate a direct relationship between learning difficulties, when it comes to learning arbitrary conditional relations, and the occurrence of cognitive decline. Therefore, the administration of the conditional relations tasks could be useful for distinguishing older adults with and without AD. Keywords: Conditional discrimination; neuropsychological tests; elderly; Alzheimer's Disease

Estudios para evaluar el hierro corporal

Objetive: Multi-parameter studies combining serum Transferrin Receptor (sTfR) with Ferritin, hemoglobin,transferrin saturation percentage for an assessment of iron status. Materials and Methods.Subjects:Healthy Adults (HA)(n=51) and Iron-Deficient Anemic Patients (IDAP) (n=50). sTfR and Ferritin weremeasured by ELISA. Results: Mean confidence interval IC95(μ) showed that the mean value for sTfRwas 15.5-18.1 nmol/L (95% probability) in HA group. In IDAP both the sTfR mv and range (66.3 nmol/L, 16.1-148.4 nmol/L, (α) 0.05), and the sTfR/F Index (75.8) were greater than in HA (5% significancelevel). TfR/Hb (p<0.001), 71% (r2), and Ferritin/Hb (p<0.001), 70 % (r2), showed that for Hb <120g/L, sTfR is more sensitive than Ferritin. sTfR/Ferritin (p<0.001), 72% (r2) showed significant sTfRincreases for ferritins <12μg/L. Conclusion: Our studies confirm that the sTfR detects iron-sensitivechanges with a diagnostic accuracy. The combined use of sTfR and conventional parameters allows foreasier iron status assessment.Objetivos: Evaluar el estado del hierro del organismo mediante estudios multiparamétricos combinandoel receptor de transferrina soluble (RTfs) con Ferritina, hemoglobina, saturación de transferrina (%).Materiales y Métodos: Adultos Sanos (AS)(n=51) y Anémicos Ferroprivos (AF)(n=50). RTfs y Ferritinase determinaron por ELISA. Resultados: El intervalo de confianza de la media del RTfs IC95(μ) fue15.5-18.1 nmol/L con un 95% de probabilidad en AS. En el grupo AF el mv y rango del RTfs fueron66.3 nmol/L y 16.1-148.4 nmol/L, (α) 0.05, respectivamente, y el índice RTfs/F fue mayor (75.8) queen AS (nivel de significación 5%).El estudio de la relación RTfs/Hb (p<0.001), 71% (r2) y Ferritina/Hb (p<0.001), 70 % (r2), mostró que para valores de Hb <120g/L, el RTfs es más sensible que laFerritina. El índice RTfs/F (p<0,001), 72% (r2) mostró aumentos significativos para valores de Ferritinas<12μg/L. Conclusiones: Nuestros estudios confirman que el RTfs detecta con eficiencia diagnósticacambios sensibles del hierro funcional. El uso combinado del RTfs con parámetros convencionalespermite una rápida evaluación del estado del hierro

Effect of major school playground reconstruction on physical activity and sedentary behaviour: Camden active spaces.

BACKGROUND: The physical school environment is a promising setting to increase children's physical activity although robust evidence is sparse. We examined the effects of major playground reconstruction on physical activity and sedentary time in primary schools using a quasi-experimental design (comparison group pre-test/post-test design). METHODS: Five experimental and two control schools from deprived areas of inner city London were recruited at baseline. Main outcome was physical activity and sedentary time measured from objective monitoring (Actigraph accelerometer) at one year follow up. Pupils' impressions of the new playground were qualitatively assessed post construction. RESULTS: A total of 347 pupils (mean age = 8 years, 55% boys; 36% Caucasian) were recruited into the study at baseline; 303 provided valid baseline Actigraph data. Of those, 231 (76%) completed follow-up (n = 169 intervention; n = 62 control) and 77.4% of the sample recorded at least 4 days of Actigraph wear. In mixed models adjusted for age, sex, ethnicity, ratio activity or sedentary/wear time at baseline, wear time at follow up, and school, no differences were observed in total moderate - vigorous activity (B = -1.4, 95% CI, -7.1, 4.2 min/d), light activity (B = 4.1, 95% CI, -17.9, 26.1), or sedentary time (B = -3.8, 95% CI, -29.2, 21.6 min/d) between groups. There were significant age interactions for sedentary (p = 0.002) and light intensity physical activity (p = 0.008). We observed significant reductions in total sedentary (-28.0, 95% CI, -1.9, -54.1 min/d, p = 0.037) and increases in total light intensity activity (24.6, 95% CI, 0.3, 48.9 min/d, p = 0.047) for children aged under 9 yrs. old in the intervention. CONCLUSION: Major playground reconstruction had limited effects on physical activity, but reduced sedentary time was observed in younger children. Qualitative data suggested that the children enjoyed the new playgrounds and experienced a perceived positive change in well-being and social interactions

High incidence of autoantibodies in Fabry disease patients

Fabry disease (FD) is an X-linked disorder of glycosphingolipid catabolism that results from a deficiency of the lysosomal enzyme α-galactosidase A. This defect leads to the accumulation of its substrates, mainly globotriaosylceramide, in lysosomes of cells of different tissues. Different studies have shown the involvement of immunopathologies in different sphingolipidoses. The coexistence of FD and immune disorders such as systemic lupus erythematosus, rheumatoid arthritis and IgA nephropathy, has been described in the literature. The aim of this study was to evaluate the prevalence of a group of autoantibodies in a series of Argentine FD patients. Autoantibodies against extractable nuclear antigens (ENAs), double-stranded DNA, anticardiolipin and phosphatidylserine were assayed by ELISA. Lupus anticoagulants were also tested. Fifty-seven per cent of the samples showed reactivity with at least one autoantigen. Such reactivities were more frequent among males than among females. Antiphospholipid autoantibodies were detected in 45% of our patients. The high rate of thrombosis associated with FD could be related, at least in part, to the presence of antiphospholipid autoantibodies in Fabry patients. We found the presence of ENAs, which are a characteristic finding of rheumatological diseases, previous a frequent misdiagnosis of FD, in around 39% of the cases. The detection of a high level of autoantibodies must be correlated clinically to determine the existence of an underlying autoimmune disease. With the recent development of therapy, the life expectancy in FD will increase and autoimmune diseases might play an important role in the morbidity of FD.Facultad de Ciencias ExactasLaboratorio de Investigaciones del Sistema Inmun

FORMAÇÃO DE CLASSES DE ESTÍMULOS EQUIVALENTES EM IDOSOS COM IDADE AVANÇADA

The present study evaluated empirically the formation of equivalence classes with elderly participants using the structure of “comparison-as-node” (CaN) training and the training design of the baseline conditional relations and the probe for emergent relations called “simple to complex”. Three participants aged between 76 and 83 years old were exposed to a matching to sample procedure to learn new conditional discriminations between arbitrary stimuli and then such relations were tested to check for the formation of equivalence classes. The results demonstrated that the participants learned the conditional relations, requiring on average between 4.83 and 8.37 repetitions of the baseline training blocks. All participants reached a score of more than 80% in the equivalence test. Thus it was possible to observe the emergence of equivalence classes with elderly participants using the structure of CaN training and the training design “simple to complex”. Key words: stimulus equivalence, matching to sample, equivalence class formation, elderly.O objetivo do presente estudo foi verificar empiricamente a formação de classes equivalentes com participantes com idade avançada utilizando a estrutura de treino CaN e arranjo de treinos e testes do “simples para o complexo”. Três idosos, entre 76 e 83 anos, foram expostos ao procedimento de ensino baseado em emparelhamento com o modelo com o propósito de ensinar-lhes novas discriminações condicionais entre estímulos abstratos e depois testar essas relações para averiguar a formação de classes equivalentes. Os resultados demonstraram que os participantes aprenderam as relações condicionais, requerendo um número de repetições dos blocos de treino de linha de base que variou entre 4,83 e 8,37 em média. Além disso, os três participantes apresentaram no teste de equivalência porcentagem de acertos acima de 80%. Dessa forma, foi possível observar sistematicamente a formação de classes de equivalência com participantes idosos usando a estrutura de treino CaN e o arranjo de treinos e testes do “simples para o complexo”.Palavras-chave: equivalência de estímulos, emparelhamento com o modelo, formação de classes equivalentes,idosos

Effects of reallocating time in different activity intensities on health and fitness: a cross sectional study

BACKGROUND: The effects of replacing time in specific activity categories for other categories (e.g. replacing sedentary time with light activity) on health and fitness are not well known. This study used isotemporal substitution to investigate the effects of substituting activity categories in an equal time exchange fashion on health and fitness in young people. METHODS: Participants were drawn from schools in Camden, London (n = 353, mean age 9.3 ± 2.3 years). Time sedentary, in light and in moderate-to-vigorous activity (MVPA) was measured via accelerometry. The effects of substituting time in activity categories (sedentary, light and MVPA) with equivalent time in another category on health and fitness were examined using isotemporal substitution. RESULTS: In single and partition models, MVPA was favourably associated with body fat %, horizontal jump distance and flexibility. Time sedentary and in light activity were not associated with health and fitness outcomes in these models. In substitution models, replacing one hour of sedentary time with MVPA was favourably associated with body fat % (B = -4.187; 95% confidence interval (CI), -7.233, -1.142), horizontal jump distance (B = 16.093; 95% CI, 7.476, 24.710) and flexibility (B = 4.783; 95% CI, 1.910, 7.656). Replacing time in light activity with MVPA induced similar benefits but there were null effects for replacing sedentary with light intensity. CONCLUSION: Substituting time sedentary and in light activity with MVPA was associated with favourable health and fitness. Time in sedentary behaviour may only be detrimental to health and fitness when it replaces time in MVPA in young people

Global metabolic response of Enterococcus faecalis to oxygen

Oxygen and oxidative stress have become relevant components in clarifying the mechanism that weakens bacterial cells in parallel to the mode of action of bactericidal antibiotics. Given the importance of oxidative stress in the overall defense mechanism of bacteria and their apparent role in the antimicrobial mode of action, it is important to understand how bacteria respond to this stress at a metabolic level. The aim of this study was to determine the impact of oxygen on the metabolism of the facultative anaerobe Enterococcus faecalis using continuous culture, metabolomics and 13C-enrichment of metabolic intermediates. When E. faecalis was rapidly transitioned from anaerobic to aerobic growth, cellular metabolism was directed towards intracellular glutathione production and glycolysis was upregulated two-fold, which increased the supply of critical metabolite precursors (e.g. glycine and glutamate) for sulfur metabolism and glutathione biosynthesis as well as reducing power for cellular respiration in the presence of haemin. The ultimate metabolic response of E. faecalis to an aerobic environment was the upregulation of fatty acid metabolism and benzoate degradation, which was linked to important changes in the bacterial membrane composition as evidenced by changes in membrane fatty acid composition and the reduction of membrane-associated demethylmenaquinone. These key metabolic pathways associated with the response of E. faecalis to oxygen may represent potential new targets to increase the susceptibility of this bacterium to bactericidal drugs.This work was funded by the HRC (Health and Research Council of New Zealand) and the FCT (Portuguese Foundation for Science and Technology), with grant reference SFRH/BD/47016/2008