Are There Clinical Cardiac Complications From Too Much Exercise?

The dose-response association between physical activity and cardiovascular outcomes is well described (10). As little as 15 min·d−1 of moderate-intensity exercise significantly lowers the risk for cardiovascular morbidity and mortality. Greater volumes yield greater cardiovascular benefit. However, the impact of extreme volumes of exercise on cardiovascular health is under debate (9), because some studies present evidence of adverse clinical outcomes in endurance athletes who perform exercise volumes at the extreme upper end of the physical activity continuum. These observations raise the possibility that high doses of exercise have deleterious cardiac effects

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu

Exploring the utility of Acxiom’s Research Opinion Poll data for use in social science research

Acxiom’s Research Opinion Poll (ROP), a voluntary survey designed to capture detailed information about household consumption and expenditure across Great Britain, has the potential to provide information valuable for social science research. This paper provides a review of the ROP, indicating that the survey in undertaken through a number of channels which enable Acxiom to generate over one million household responses a year. The ROP micro data collected are used in the construction of many of Acxiom’s aggregate products including its geo-demographic classification system called ‘PersonicX’. The ROP is found to compare favourably in areas such as sample size, geographic detail, consistency and data quality and accuracy when compared against government datasets including the 2001 Census, the Living Costs and Food Survey, the Labour Force Survey, the British Household Panel Survey, the General Lifestyle Survey and the English Housing Survey

Limb amputations in fixed dystonia: a form of body integrity identity disorder?

Fixed dystonia is a disabling disorder mainly affecting young women who develop fixed abnormal limb postures and pain after apparently minor peripheral injury. There is continued debate regarding its pathophysiology and management. We report 5 cases of fixed dystonia in patients who sought amputation of the affected limb. We place these cases in the context of previous reports of patients with healthy limbs and patients with chronic regional pain syndrome who have sought amputation. Our cases, combined with recent data regarding disorders of mental rotation in patients with fixed dystonia, as well as previous data regarding body integrity identity disorder and amputations sought by patients with chronic regional pain syndrome, raise the possibility that patients with fixed dystonia might have a deficit in body schema that predisposes them to developing fixed dystonia and drives some to seek amputation. The outcome of amputation in fixed dystonia is invariably unfavorable

Exercise and Coronary Atherosclerosis: Observations, Explanations, Relevance, and Clinical Management.

Physical activity and exercise training are effective strategies for reducing the risk of cardiovascular events, but multiple studies have reported an increased prevalence of coronary atherosclerosis, usually measured as coronary artery calcification, among athletes who are middle-aged and older. Our review of the medical literature demonstrates that the prevalence of coronary artery calcification and atherosclerotic plaques, which are strong predictors for future cardiovascular morbidity and mortality, was higher in athletes compared with controls, and was higher in the most active athletes compared with less active athletes. However, analysis of plaque morphology revealed fewer mixed plaques and more often only calcified plaques among athletes, suggesting a more benign composition of atherosclerotic plaques. This review describes the effects of physical activity and exercise training on coronary atherosclerosis in athletes who are middle-aged and older and aims to contribute to the understanding of the potential adverse effects of the highest doses of exercise training on the coronary arteries. For this purpose, we will review the association between exercise and coronary atherosclerosis measured using computed tomography, discuss the potential underlying mechanisms for exercise-induced coronary atherosclerosis, determine the clinical relevance of coronary atherosclerosis in middle-aged athletes and describe strategies for the clinical management of athletes with coronary atherosclerosis to guide physicians in clinical decision making and treatment of athletes with elevated coronary artery calcification scores

Sentrin/sumo Specific Proteases As Novel Tissue-selective Modulators Of Vitamin D Receptor-mediated Signaling

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Evidence for variation in the effective population size of animal mitochondrial DNA

Background: It has recently been shown that levels of diversity in mitochondrial DNA are remarkably constant across animals of diverse census population sizes and ecologies, which has led to the suggestion that the effective population of mitochondrial DNA may be relatively constant. Results: Here we present several lines of evidence that suggest, to the contrary, that the effective population size of mtDNA does vary, and that the variation can be substantial. First, we show that levels of mitochondrial and nuclear diversity are correlated within all groups of animals we surveyed. Second, we show that the effectiveness of selection on non-synonymous mutations, as measured by the ratio of the numbers of non-synonymous and synonymous polymorphisms, is negatively correlated to levels of mitochondrial diversity. Finally, we estimate the effective population size of mitochondrial DNA in selected mammalian groups and show that it varies by at least an order of magnitude. Conclusions: We conclude that there is variation in the effective population size of mitochondria. Furthermore we suggest that the relative constancy of DNA diversity may be due to a negative correlation between the effective population size and the mutation rate per generation

Questionnaire study to gain an insight into the manufacturing and fitting process of artificial eyes in children: an ocularist perspective

Purpose To gain an insight into the manufacturing and fitting of artificial eyes in children and potential improvements to the process. Method An online qualitative survey was distributed to 39 ocularists/prosthetists in Europe and Canada. Participants were recruited through purposive sampling, specifically maximum variation sampling from the researcher’s contacts and an online search. Results The findings highlighted the current impression technique as being the most difficult yet most important part of the current process for both the ocularist and child patient. Negatively affecting obtaining a good impression, the child patients distress can be reduced by their parents by providing encouragement, reassurance, practicing the insertion and removal of the artificial eye and being matter of fact. Whilst improvements to the current process provided mixed views, the incorporation of current technology was perceived as not being able to meet the requirements to produce aesthetically pleasing artificial eyes. Conclusion The current artificial eye process can be seen as an interaction with its success being dependent on the child patient’s acceptance and adjustment which is dependent on the factors associated to the process. Investigation into the needs of the patient and whether technology can improve the process are the next steps in its advancement

Structure and Transport in Coatings from Multiscale Computed Tomography of Coatings-New Perspectives for Eelectrochemical Impedance Spectroscopy Modeling?

Computed Tomography (CT) is an approach that has been extensively applied in many areas of science from understanding structures in living organisms to materials science. In materials science, the study of structures within coatings presents challenges on at least two different levels. First, the structure of the coatings needs to be understood from the atomic scale, where dissolution reactions begin, up to length scales which cover the aggregation of inhibitors and other additives, which take place at ∼10−5 m, i.e. 4 to 5 orders of magnitude. CT is a favourable imaging technique since it allows multiscale information to be obtained non-destructively down to tens of nanometres. In this study X-ray absorption contrast imaging has been used to examine structures created using strontium chromate (SrCrO4) particles embedded in an epoxy film. It has been found that SrCrO4 particles can form clusters that extend a few hundred microns in the plane of the film, span the thickness of the film and have fractal characteristics. There are also volumes of low density epoxy of similar sizes and characteristics to the SrCrO4 clusters. The SrCrO4 clusters have a strong influence on the leaching behaviour since the release changes with time. Initially, leaching is controlled by direct dissolution but, as the clusters dissolve, the release is dominated by the fractal dimension of the cluster. The dissolved clusters leave behind voids filled with electrolyte that provide alternative transport pathways for corrosive ions through the polymer. In this paper, the nature of these clusters will be reviewed and the implication for transport properties and electrochemical assessment will be explored

The Relationship Between Lifelong Exercise Volume and Coronary Atherosclerosis in Athletes.

Background -Higher levels of physical activity are associated with a lower risk of cardiovascular events. Nevertheless, there is debate on the dose-response relationship of exercise and CVD outcomes and whether high volumes of exercise may accelerate coronary atherosclerosis. We aimed to determine the relationship between lifelong exercise volumes and coronary atherosclerosis. Methods -Middle aged men engaged in competitive or recreational leisure sports underwent a non-contrast and contrast-enhanced computed tomography scan to assess coronary artery calcification (CAC) and plaque characteristics. Participants reported lifelong exercise history patterns. Exercise volumes were multiplied by Metabolic Equivalent of Task (MET) scores to calculate MET-min/week. Participants were categorized as 2000 MET-min/week. Results -284 men (55±7 years) were included. CAC was present in 150/284 (53%) participants with a median CAC score of 35.8 [9.3-145.8). Athletes with a lifelong exercise volume >2000 MET-min/week (n=75) had a significantly higher CAC score (9.4 [0-60.9] versus 0 [0-43.5], p=.02) and prevalence of CAC (68%,ORadjusted=3.2 (95%CI: 1.6-6.6)) and plaque (77%, ORadjusted=3.3 (95%CI: 1.6-7.1)) compared to 0, there was no difference in CAC score (p=.20), area (p=.21), density (p=.25) and regions of interest (p=.20) across exercise volume groups. Among participants with plaque, the most active group (>2000 MET-min/week) had a lower prevalence of mixed plaques (48% versus 69%, ORadjusted=0.35 (95%CI: 0.15-0.85) and more often had only calcified plaques (38% versus 16%, ORadjusted=3.57 (95%CI: 1.28-9.97)) compared to the least active group (2000 MET-min/week group had a higher prevalence of CAC and atherosclerotic plaques. The most active group did however have a more benign composition of plaques, with fewer mixed plaques and more often only calcified plaques. These observations may explain the increased longevity typical of endurance athletes despite the presence of more coronary atherosclerotic plaque in the most active participants