Effects of Age and Sex on Inspiratory Muscle Activation Patterns During Exercise

Purpose: Characterize the effects of age, sex, and their interaction on inspiratory muscle activation patterns during exercise. Methods: Twenty younger (20-30y, n=10 women) and twenty older (60-80y, n=10 women) subjects performed an incremental cycle exercise test. Electromyography of the scalene (EMGsca) and sternocleidomastoid (EMGscm) muscles were measured using skin surface electrodes, while diaphragm electromyography (EMGdi) and esophageal and transdiaphragmatic pressures were measured using an esophageal catheter. Electromyography data were transformed into root-mean-square with a 100ms time constant. Esophageal (PTPes) and diaphragmatic (PTPdi) pressure-time products were used as indices of total inspiratory muscle pressure production and diaphragmatic pressure production, respectively. Results: At absolute minute ventilations (V E), women and older subjects had greater EMGdi than men and younger subjects, respectively (all p<0.05), but no differences were noted when V E was expressed in relative terms (all p>0.05). Women had greater EMGsca activity than men at absolute and relative levels of V E (all p<0.05). Older subjects had greater EMGsca than younger subjects when V E was expressed relative (all p<0.05) but not absolute terms (all p>0.05). At absolute and relative levels of V E, women and older subjects had greater EMGscm than men and younger subjects, respectively (all p<0.05). Women and older subjects had a greater PTPdi/PTPes at a V E of 70 l·min-1 than men and younger subjects, respectively (both p<0.05), but no differences were noted when V E was expressed in relative terms (all p>0.05). No significant interactions between age and sex were noted (all p>0.05). Conclusion: Age and sex significantly affect inspiratory muscle activation patterns during exercise; however, the extent of the effects depends on whether comparisons are made at a solute or relative V E.This study was supported by the British Columbia Lung Association (BCLA). YMS, PBD, and AHR were supported by graduate scholarships from the Natural Sciences and Engineering Research Council of Canada (NSERC). PBD and MRS were supported by fellowships from the University of British Columbia and BCLA. JAG was supported by a Scholar Award from the Michael Smith Foundation for Health Research, a New Investigator Award from the Providence Health Care Research Institute and St. Paul’s Hospital Foundation, and a Canadian Institutes of Health Research Clinical Rehabilitation New Investigator Award

Manipulation of mechanical ventilatory constraint during moderate intensity exercise does not influence dyspnoea in healthy older men and women

© 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society. KEY POINT SUMMARY:The perceived intensity of exertional breathlessness (i.e. dyspnoea) is higher in older women than in older men, possibly due to sex-difference respiratory system morphology. During exercise at a given absolute intensity or minute ventilation, older women have a greater degree of mechanical ventilatory constraint (i.e. work of breathing and expiratory flow limitation) than their male counterparts, which may lead to a greater perceived intensity of dyspnoea. Using a single-blind randomized study design, we experimentally manipulated the magnitude of mechanical ventilatory constraint during moderate-intensity exercise at ventilatory threshold in healthy older men and women. We found that changes in the magnitude of mechanical ventilatory constraint within the physiological range had no effect on dyspnoea in healthy older adults. When older men and women perform submaximal exercise at a moderate intensity, mechanical ventilatory constraint does not contribute significantly to the sensation of dyspnoea. We sought to determine the effect of manipulating mechanical ventilatory constraint during submaximal exercise on dyspnoea in older men and women. METHODS:Eighteen healthy subjects (60-80 y; 9 men, 9 women) completed two days of testing. On Day 1, subjects performed pulmonary function testing and a maximal incremental cycle exercise test. On Day 2, subjects performed three 6-min bouts of cycling at ventilatory threshold, in a single-blind randomized manner, while breathing: i) normoxic helium-oxygen (HEL) to reduce the work of breathing (Wb ) and alleviate expiratory flow limitation (EFL); ii) through an inspiratory resistance (RES) of ∼5 cmH2 O·l-1 ·s-1 to increase Wb ; and iii) ambient air as a control (CON). Oesophageal pressure, diaphragm electromyography, and sensory responses (using the category-ratio 10 Borg scale) were monitored throughout exercise. RESULTS:During the HEL condition, there was a significant decrease in Wb (men: -21 ± 6%, women: -17 ± 10%) relative to CON (both p < 0.01). Moreover, if EFL was present during CON (4 men, 5 women), it was alleviated during HEL. Conversely, during the RES condition, Wb (men: 42 ± 19%, women: 50 ± 16%) significantly increased relative to CON (both p < 0.01). There was no main effect of sex on Wb (p = 0.59). Across conditions, women reported significantly higher dyspnoea intensity than men (2.9 ± 0.9 vs. 1.9 ± 0.8 Borg scale units, p < 0.05). Despite significant differences in the degree of mechanical ventilatory constraint between conditions, dyspnoea intensity was unaffected, independent of sex (p = 0.46). CONCLUSION:When older men and women perform submaximal exercise at a moderate intensity, mechanical ventilatory constraint does not contribute significantly to the sensation of dyspnoea. This article is protected by copyright. All rights reserved.Natural Science and Engineering Research Council of Canada (NSERC) British Columbia Lung Association (BCLA

Extrusion of Endodontic Filling Materials: Medico-Legal Aspects. Two Cases

The Authors describe two cases of alleged malpractice due to overfilling. The aim of this article is to underline some medico-legal aspects regarding the quantity of extruded material which may be considered acceptable and the consequent damage to the patient

Developing a tool to measure health worker motivation in district hospitals in Kenya

BACKGROUND: We wanted to try to account for worker motivation as a key factor that might affect the success of an intervention to improve implementation of health worker practices in eight district hospitals in Kenya. In the absence of available tools, we therefore aimed to develop a tool that could enable a rapid measurement of motivation at baseline and at subsequent points during the 18-month intervention study. METHODS: After a literature review, a self-administered questionnaire was developed to assess the outcomes and determinants of motivation of Kenyan government hospital staff. The initial questionnaire included 23 questions (from seven underlying constructs) related to motivational outcomes that were then used to construct a simpler tool to measure motivation. Parallel qualitative work was undertaken to assess the relevance of the questions chosen and the face validity of the tool. RESULTS: Six hundred eighty-four health workers completed the questionnaires at baseline. Reliability analysis and factor analysis were used to produce the simplified motivational index, which consisted of 10 equally-weighted items from three underlying factors. Scores on the 10-item index were closely correlated with scores for the 23-item index, indicating that in future rapid assessments might be based on the 10 questions alone. The 10-item motivation index was also able to identify statistically significant differences in mean health worker motivation scores between the study hospitals (p<0.001). The parallel qualitative work in general supported these conclusions and contributed to our understanding of the three identified components of motivation. CONCLUSION: The 10-item score developed may be useful to monitor changes in motivation over time within our study or be used for more extensive rapid assessments of health worker motivation in Kenya

Pre-processing Agilent microarray data

<p>Abstract</p> <p>Background</p> <p>Pre-processing methods for two-sample long oligonucleotide arrays, specifically the Agilent technology, have not been extensively studied. The goal of this study is to quantify some of the sources of error that affect measurement of expression using Agilent arrays and to compare Agilent's Feature Extraction software with pre-processing methods that have become the standard for normalization of cDNA arrays. These include log transformation followed by loess normalization with or without background subtraction and often a between array scale normalization procedure. The larger goal is to define best study design and pre-processing practices for Agilent arrays, and we offer some suggestions.</p> <p>Results</p> <p>Simple loess normalization without background subtraction produced the lowest variability. However, without background subtraction, fold changes were biased towards zero, particularly at low intensities. ROC analysis of a spike-in experiment showed that differentially expressed genes are most reliably detected when background is not subtracted. Loess normalization and no background subtraction yielded an AUC of 99.7% compared with 88.8% for Agilent processed fold changes. All methods performed well when error was taken into account by t- or z-statistics, AUCs ≥ 99.8%. A substantial proportion of genes showed dye effects, 43% (99%<it>CI </it>: 39%, 47%). However, these effects were generally small regardless of the pre-processing method.</p> <p>Conclusion</p> <p>Simple loess normalization without background subtraction resulted in low variance fold changes that more reliably ranked gene expression than the other methods. While t-statistics and other measures that take variation into account, including Agilent's z-statistic, can also be used to reliably select differentially expressed genes, fold changes are a standard measure of differential expression for exploratory work, cross platform comparison, and biological interpretation and can not be entirely replaced. Although dye effects are small for most genes, many array features are affected. Therefore, an experimental design that incorporates dye swaps or a common reference could be valuable.</p

Decreased Prevalence of Lymphatic Filariasis among Diabetic Subjects Associated with a Diminished Pro-Inflammatory Cytokine Response (CURES 83)

Epidemiological studies have shown an inverse correlation between the incidence of lymphatic filariasis (LF) and the incidence of allergies and autoimmunity. However, the interrelationship between LF and type-2 diabetes is not known and hence, a cross sectional study to assess the baseline prevalence and the correlates of sero-positivity of LF among diabetic subjects was carried out (n = 1416) as part of the CURES study. There was a significant decrease in the prevalence of LF among diabetic subjects (both newly diagnosed [5.7%] and those under treatment [4.3%]) compared to pre-diabetic subjects [9.1%] (p = 0.0095) and non-diabetic subjects [10.4%] (p = 0.0463). A significant decrease in filarial antigen load (p = 0.04) was also seen among diabetic subjects. Serum cytokine levels of the pro-inflammatory cytokines—IL-6 and GM-CSF—were significantly lower in diabetic subjects who were LF positive, compared to those who were LF negative. There were, however, no significant differences in the levels of anti-inflammatory cytokines—IL-10, IL-13 and TGF-β—between the two groups. Although a direct causal link has yet to be shown, there appears to be a striking inverse relationship between the prevalence of LF and diabetes, which is reflected by a diminished pro-inflammatory cytokine response in Asian Indians with diabetes and concomitant LF

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Trend in eating habits among Lithuanian school-aged children in context of social inequality: three cross-sectional surveys 2002, 2006 and 2010

<p>Abstract</p> <p>Background</p> <p>Intermittent monitoring of food intake at the population level is essential for the planning and evaluation of national dietary intervention programs. Social-economic changes in Lithuania have likely affected dietary habits, but only a limited number of temporal studies on food intake trends among young population groups have been published. The aim of this study was to investigate changes in eating habits among Lithuanian school-aged children from 2002 to 2010, and to explore the association of these changes with the respondents' reported socio-economic status (SES).</p> <p>Methods</p> <p>We used Lithuanian data from the cross-national Health Behaviour in School-aged Children (HBSC) study collected in 2002, 2006 and 2010. Analyses were conducted on comparable questionnaire-based data from children aged 11, 13 and 15 (total n = 17,189) from a random sample of schools. A food frequency questionnaire was used to investigate frequencies of food consumption. Logistic regression was used to examine the affects of changing social variables on reported diet trends.</p> <p>Results</p> <p>In Lithuania, school-aged children have low intakes of fruits and vegetables. Only 21.1% of boys and 27.1% of girls reported daily fruit consumption. Similarly, 24.9% of boys and 29.6% of girls disclosed vegetable intake at least once daily. Comparing 2010 to 2002, the proportion of girls who consumed fruits daily increased from 24.2% to 31.0% (p < 0.001) but the proportion of boys who consumed vegetables daily decreased from 29.3% to 23.1% (p < 0.001). In 2006, for both sexes, there were observed increases in regular (at least five days a week) intake of sweets and chocolates, biscuits and pastries, and soft drinks; however, in the next survey (2010) these figures decreased. In addition, between 2006 and 2010, a substantial decrease in regular consumption of chips and fast food was also detected. Fruit and vegetable consumption as well as intake of sweets and chocolates, biscuits and pastries and soft drinks increased with family social-economic status and family material wealth. Trends in consumption of fruits, and other foods, and their association with changing social variables were demonstrated using the ORs estimated by three logistic models, using 2002 as the reference point. Changes in social variables from 2002 to 2010 affected the likelihood of daily consumption of fruits among boys by 22.5% (the corresponding OR decreased from 1.11 to 0.86) and among girls by 34.0% (the corresponding OR decreased from 1.41 to 1.12). Over the study period, changing social variables had little impact on the daily consumption of vegetables and other foods.</p> <p>Conclusions</p> <p>Based on the food consumption trends observed in Lithuania, increases in consumption of fruits and vegetables should be promoted, along with a reduction in the intake of less healthy choices, such as soft drinks and high-fat, high-sugar snack foods, by diminishing social inequalities in food consumption.</p

Young carers in Germany: to live on as normal as possible – a grounded theory study

<p>Abstract</p> <p>Background</p> <p>In contrast to a growing body of research on the situation of adult family care givers, in Germany hardly anything is known about the situation of children and teenagers who are involved in the care of their relatives.</p> <p>Methods</p> <p>In this Grounded Theory study 81 semi structured interviews have been carried out with children and their parents in 34 families, in which one member is chronically ill. 41 children and 41 parents participated and the sample is heterogeneous and diverse.</p> <p>Results</p> <p>On the one hand, there is the phenomenon 'keeping the family together", which describes how families themselves cope with the chronic illness and also, which tasks to what extent are being shifted and redistributed within the family in order to manage daily life. Influencing factors, the children's motives as well as the impact on the children also belong to this phenomenon. The second phenomenon 'to live a normal course of life' describes concrete wishes and expectations of support for the family to manage the hindered daily life. These two phenomena linked together constitute the 'model of experience and construction of familial care, in which children take over an active role'.</p> <p>Conclusion</p> <p>It will be discussed, that the more families are in dire need of support, the more their distress becomes invisible, furthermore, that management of chronic illness is a process, in which the entire family is involved, and thus needs to be considered, and finally, that young carer's relief is not possible without relief of their parents.</p

The use of health-related quality of life (HRQOL) in children and adolescents as an outcome criterion to evaluate family oriented support for young carers in Germany: an integrative review of the literature

<p>Abstract</p> <p>Background</p> <p>Young people below the age of 18, whose lives are affected by looking after a relative with a disability or long-term illness, are called young carers. Evidence based family oriented support for young carers and their families in Germany is currently being developed. To allow for scientific evaluation, an outcome criterion needs to be chosen. Until today, there are no assessment instruments available, which focus on young carer's specific demands and needs. As HRQOL seems to be an adequate alternative outcome criterion, an integrative review of the literature was carried out to verify this assumption.</p> <p>Methods</p> <p>The aim of the integrative review was to get information about a) the concept and the common definition of HRQOL in children, b) preferable HRQOL assessment techniques in children, and c) the relevance of HRQOL measures for the population of young carers. An additional aim of the review was to give advice on which instrument fits best to assess young carer's HRQOL in Germany. Searches were conducted in PubMed in order to obtain papers reporting about a) the development or psychometric assessment of instruments measuring HRQOL in children and adolescents up to the age of 18, and b) on the conceptual framework of HRQOL in children.</p> <p>Results</p> <p>HRQOL is a multidimensional construct covering physical, emotional, mental, social, and behavioural components of well-being and functioning as subjective perceived by a person depending on the cultural context and value system one is living in. Young carer's problems and needs are well covered by these common domains of HRQOL. Since no specific HRQOL-measures are available to address young carers, a generic one has to be chosen which a) has been created for use in children, b) allows self- and proxy-report, and c) has good psychometric testing results. Comparing four generic measures with currently best published psychometric testing results, items of the KIDSCREEN cover young carer's specific problems most accurate.</p> <p>Conclusion</p> <p>The KIDSCREEN questionnaires seems adequate to evaluate the intervention as their items cover young carer's needs and problems most accurate.</p