77 research outputs found

    Measuring cardiomyocyte cellular characteristics in cardiac hypertrophy using diffusion‐weighted MRI

    Get PDF
    Purpose: This paper presents a hierarchical modeling approach for estimating cardiomyocyte major and minor diameters and intracellular volume fraction (ICV) using diffusion‐weighted MRI (DWI) data in ex vivo mouse hearts. Methods: DWI data were acquired on two healthy controls and two hearts 3 weeks post transverse aortic constriction (TAC) using a bespoke diffusion scheme with multiple diffusion times ( Δ Δ \Delta ), q‐shells and diffusion encoding directions. Firstly, a bi‐exponential tensor model was fitted separately at each diffusion time to disentangle the dependence on diffusion times from diffusion weightings, that is, b‐values. The slow‐diffusing component was attributed to the restricted diffusion inside cardiomyocytes. ICV was then extrapolated at Δ = 0 Δ=0 \Delta =0 using linear regression. Secondly, given the secondary and the tertiary diffusion eigenvalue measurements for the slow‐diffusing component obtained at different diffusion times, major and minor diameters were estimated assuming a cylinder model with an elliptical cross‐section (ECS). High‐resolution three‐dimensional synchrotron X‐ray imaging (SRI) data from the same specimen was utilized to evaluate the biophysical parameters. Results: Estimated parameters using DWI data were (control 1/control 2 vs. TAC 1/TAC 2): major diameter—17.4 μ μ \mu m/18.0 μ μ \mu m versus 19.2 μ μ \mu m/19.0 μ μ \mu m; minor diameter—10.2 μ μ \mu m/9.4 μ μ \mu m versus 12.8 μ μ \mu m/13.4 μ μ \mu m; and ICV—62%/62% versus 68%/47%. These findings were consistent with SRI measurements. Conclusion: The proposed method allowed for accurate estimation of biophysical parameters suggesting cardiomyocyte diameters as sensitive biomarkers of hypertrophy in the heart

    Spatio-temporal atlas of bone mineral density ageing

    Get PDF
    Osteoporosis is an age-associated bone disease characterised by low bone mass. An improved understanding of the underlying mechanism for age-related bone loss could lead to enhanced preventive and therapeutic strategies for osteoporosis. In this work, we propose a fully automatic pipeline for developing a spatio-temporal atlas of ageing bone. Bone maps are collected using a dual-energy X-ray absorptiometry (DXA) scanner. Each scan is then warped into a reference template to eliminate morphological variation and establish a correspondence between pixel coordinates. Pixel-wise bone density evolution with ageing was modelled using smooth quantile curves. To construct the atlas, we amalgamated a cohort of 1714 Caucasian women (20–87 years) from five different centres in North Western Europe. As a systematic difference exists between different DXA manufacturers, we propose a novel calibration technique to homogenise bone density measurements across the centres. This technique utilises an alternating minimisation technique to map the observed bone density measurements into a latent standardised space. To the best of our knowledge, this is the first spatio-temporal atlas of ageing bone

    Gabapentin for the hemodynamic response to intubation: systematic review and meta-analysis

    Get PDF
    Purpose Endotracheal intubation is the gold standard for securing the airway before surgery. Nevertheless, this procedure can produce an activation of the sympathetic nervous system and result in a hemodynamic response which, in high-risk patients, may lead to cardiovascular instability and myocardial ischemia. The aim of this review was to evaluate whether gabapentin can attenuate this response and whether such an attenuation could translate into reduced myocardial ischemia and mortality. Source We searched MEDLINE®, EMBASE™, CINAHL, AMED, and unpublished clinical trial databases for randomized-controlled trials that compared gabapentin with control, fentanyl, clonidine, or beta blockers for attenuating the hemodynamic response to intubation. Primary outcomes were mortality, myocardial infarction, and myocardial ischemia. Secondary outcomes were hemodynamic changes following intubation. Principal findings We included 29 randomized trials with only two studies at low risk of bias. No data were provided for the primary outcomes and no studies included high-risk patients. The use of gabapentin resulted in attenuation in the rise in mean arterial blood pressure [mean difference (MD), −12 mmHg; 95% confidence interval (CI), −17 to −8] and heart rate (MD, −8 beats·min−1; 95% CI, −11 to −5) one minute after intubation. Gabapentin also reduced the risk of hypertension or tachycardia requiring treatment (risk ratio, 0.15; 95% CI, 0.05 to 0.48). Data were limited on adverse hemodynamic events such as bradycardia and hypotension. Conclusion It remains unknown whether gabapentin improves clinically relevant outcomes such as death and myocardial infarction since studies failed to report on these. Nevertheless, gabapentin attenuated increases in heart rate and blood pressure following intubation when compared with the control group. Even so, the studies included in this review were at potential risk of bias. Moreover, they did not include high-risk patients or report adverse hemodynamic outcomes. Future studies are required to address these limitations

    Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

    Get PDF
    Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

    Get PDF
    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI 2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining https://researchonline.ljmu.ac.uk/images/research_banner_face_lab_290.jpgunderweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity

    A comparative study between the effective pair potential parameters obtained from different equations of states

    No full text
    979-985Internal energy of liquid methane has been obtained based on the pair-wise additive approximation for the effective pair potential of dense fluids using (12,6) Lennard-Jones model for the intermolecular potential function. This internal energy has been compared with the internal pressure via the equation of state (EoS) expression. Thus, the effective pair potential parameters (EPPP) through some given EoSs for dense fluids have been calculated. A relation between the potential parameters with EoS parameters has been obtained. Using the obtained EPPPs and applying the pair-wise additive approximation, one could calculate accurately the thermodynamics functions such as total energy. The results of such calculations for the total energy of the liquid methane obtained via the EPPPs from different EoSs indicate a good agreement with the experimental data. Physical interpretation for the state dependencies of the obtained EPPPs from given EoSs is also presented

    Nutritional challenges of gastric cancer patients from the perspectives of patients, family caregivers, and health professionals: a qualitative study

    No full text
    Purpose: This study aims to explore the perceptions of gastric cancer patients, their family caregivers, physicians, and nurses of nutritional challenges. Methods: Using a descriptive qualitative method, this study was conducted in 2019�2020. Twenty participants (6 patients, 6 family caregivers, 3 physicians, and 5 nurses) were selected through purposive sampling. Data was collected through in-depth semi-structured interviews and examined using qualitative content analysis. Results: Data analysis revealed three categories, each with two subcategories: eating, an unpleasant experience that contains �a feeling like hyperemesis gravidarum� and �childish food excuses�; flexibility while adhering to a proper diet, which consists of �dietary dos and don�ts� and �nutritional leniency�; and nutrition with distress that contains �patient�s sense of being an extra burden� and �provision of nutrition with suffering in caregivers.� Conclusion: Because of the significant physical and psychological impact of nutritional problems on patients and their caregivers, the need to provide care and education to these patients and their families using a multidisciplinary team is becoming more important. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature

    A feasibility study on the implementation of teleconsultation in tuberculosis patients in Zabol City of Iran

    No full text
    Teleconsultation can be used for tuberculosis patients, especially in deprived area. We surveyed all of 60 employees in health centers and tuberculosis center in such area in Iran about feasibility (organizational, technical, human and environmental readiness) of implementing teleconsultation and its barriers. We found that human readiness was moderate and other aspects were weak. Furthermore, the main obstacles were the shortage of computer equipment (40), technical infrastructure (35), lack of funds (33.3), lack of awareness (33.3), and employee resistance (33.3). Implementing teleconsultation for tuberculosis patients is not completely feasible in this area and requires improvement in organizational, technical and environmental factors. © 2018 European Federation for Medical Informatics (EFMI) and IOS Press
    corecore