37 research outputs found
COPD: Do Imaging Measurements of Emphysema and Airway Disease Explain Symptoms and Exercise Capacity?
PURPOSE: To determine the role of imaging measurements of emphysema and airway disease in determining chronic obstructive pulmonary disease (COPD) symptoms and exercise limitation in patients with COPD, particularly in patients with mild-to-moderate disease.
MATERIALS AND METHODS: Participants (n = 116) with Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade U (unclassified) or grade I-IV COPD provided informed consent to an ethics board-approved HIPAA-compliant protocol and underwent spirometry and plethysmography, completed the St George\u27s Respiratory Questionnaire (SGRQ), completed a 6-minute walk test for the 6-minute walk distance (6MWD), and underwent hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging and computed tomography (CT). Emphysema was estimated by using the MR imaging apparent diffusion coefficient (ADC) and the relative area of the CT attenuation histogram with attenuation of -950 HU or less (RA950). Airway disease was measured by using the CT airway wall thickness of airways with an internal perimeter of 10 mm and total airway count. Ventilation defect percentage at (3)He MR imaging was used to measure ventilation. Multivariable regression models for the 6MWD and SGRQ symptom subscore were used to evaluate the relationships between physiologic and imaging measurements.
RESULTS: Multivariate modeling for the 6MWD in 80 patients with GOLD grade U-II COPD showed that ADC (ÎČ = 0.34, P = .04), diffusing capacity of the lung for carbon monoxide (ÎČ = 0.60, P = .0008), and residual volume/total lung capacity (ÎČ = -0.26, P = .02) were significant variables, while forced expiratory volume in 1 second (FEV1) and airway disease measurements were not. In 36 patients with GOLD grade III or IV disease, FEV1 (ÎČ = 0.48, P = .01) was the only significant contributor in a multivariate model for 6MWD. MR imaging emphysema measurements also made the greatest relative contribution to symptoms in patients with milder (GOLD grade U-II) COPD (ADC: ÎČ = 0.60, P = .005; RA950: ÎČ = -0.52, P = .02; FEV1: ÎČ = -0.45, P = .0002) and in grade III or IV disease (ADC: ÎČ = 0.95, P = .01; RA950: ÎČ = -0.62, P = .07; airway count: ÎČ = -0.49, P = .01).
CONCLUSION: In patients with mild-to-moderate COPD, MR imaging emphysema measurements played a dominant role in the expression of exercise limitation, while both CT and MR imaging measurements of emphysema explained symptoms
MRI ventilation abnormalities predict quality-of-life and lung function changes in mild-to-moderate COPD: Longitudinal TINCan study
CT biomarkers of emphysema (15th percentile of the CT density histogram, HU15%) and airways disease (wall thickness of airways with 10â
mm internal perimeter, Pi10) have shown promise for providing prognostic information.2 Although recent data3 showed that the change in CT emphysema may be used to estimate the efficacy of therapy in patients with α-1-antitrypsin-deficiency, thus far none of the currently developed CT biomarkers have been shown to reflect changes in outcomes that are important to patients with COPD. MRI with inhaled noble gases provide highly sensitive and unique microstructural and functional information in COPD.4 MRI biomarkers of COPD are highly reproducible,5 are associated with COPD outcomes6 and detect changes with greater sensitivity and before disease-related changes can be detected by CT or FEV1. Here we evaluated longitudinal changes in both CT and MRI measurements of COPD. Based on previous longitudinal results,8 ,10 we hypothesised that 3He MRI biomarkers would predict quality-of-life and FEV1 changes in COPD, and that longitudinal changes in MRI biomarkers would be correlated with changes in COPD quality-of-life measures
The mediating effect of business ethics in the relationship between total quality management and sustainable performance: perspective from 4- and 5-stars hotels
Sustainability and ethical issues in hotel industries have received great attention in recent years. This report is the outcome of a field research, which aimed to determine the relationship between TQM, business ethics and sustainable performance. The focus of this research is 4- and 5-stars hotels in Malaysia, in which 162 4- and 5-stars hotels are sampled. Quantitative approach is adopted in which structural equation modelling is employed to assess the relationship between TQM practices, business ethics and sustainable performance. The findings of this study indicate that TQM has positive impact on sustainable performance. Hence, it is concluded that the hoteliers in Malaysia are vigorously focusing on implementation of TQM practices in order to achieve sustainability. Besides, these research findings show that business ethics play as the role of mediator in the relationship of TQM and sustainable performance. The proposed framework serves as a guideline to verify the significance of TQM practices as well as business ethics in order to leverage the hotels' sustainable performance
Does the Factors Affecting Gold Price Changed During Covid-19 Period in Malaysia?
This paper examines whether Covid-19 pandemic has changed the main economy factors affecting gold prices, and the relationship between KLCI and gold price in Malaysia. Gold plays an important role in an economy during normal and uncertain market situations. This research involved 62 monthly data covering the period of January 2016 to February 2021. Unit root and diagnostic tests are conducted on the data to ensure the results are valid. There are six macroeconomic variables involved, five of them are the independent variables and the remaining one is dependent variable. Multiple regression time series analysis is use to analyse the data in the perspectives of full sample, pre- Covid-19 period and during Covid-19 period. The results of this study found that few main economy factors ceased to be significant, and there is change relationship direction between exchange rate and gold price during Covid-19 period. We discovered KLCI has an inverse relationship with gold price. Future research can consider extending our analysis to neighbouring countries
Pulmonary Abnormalities and Carotid Atherosclerosis in Ex-Smokers without Airflow Limitation.
Abstract It is well-established that COPD patients have a burden of vascular disease that cannot be fully-explained by smoking history but the mechanistic links between atherosclerosis and pulmonary disease in COPD patients are not well-understood. Moreover, in ex-smokers without symptoms or other evidence of COPD, subclinical pulmonary and vascular disease, although potentially present, has not been described or evaluated. Hence our aim was to use sensitive three-dimensional (3D) pulmonary and carotid imaging to quantify pulmonary airway/parenchyma abnormalities and atherosclerosis in ex-smokers without airflow limitation or symptoms consistent with COPD. We evaluated 61 subjects without airflow limitation including 34 never- (72 ± 6 years) and 27 ex-smokers (73 ± 9 years), who provided written informed consent to spirometry, plethysmography, (3)He magnetic resonance imaging (MRI) and carotid ultrasound (US) and, for ex-smokers alone, thoracic X-ray computed tomography (CT). Ex-smokers had significantly greater (3)He ventilation defect percent (VDP = 7%, p = 0.001) and carotid total plaque volume (TPV = 250 mm(3), p = 0.002) than never-smokers, although there were no significant differences for spirometry or plethysmography, and CT airway and emphysema measurements were normal. There were univariate relationships for (3)He VDP with carotid intima media thickness (IMT, r = 0.42, p = 0.004), TPV (r = 0.41, p = 0.006) and vessel wall volume (VWV, r = 0.40, p = 0.007). Multivariate models that included age, BMI, FEV1, DLCO and VDP showed that only VDP significantly predicted IMT (ÎČ = 0.41, p = 0.001), VWV (ÎČ = 0.45, p = 0.003) and TPV (ÎČ = 0.38, p = 0.005). In summary, there was imaging evidence of mild airways disease and carotid plaque burden that were related and significantly greater in ex-smokers without airflow limitation than in never-smokers
Defining the role of common variation in the genomic and biological architecture of adult human height
Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explain one-fifth of heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ~2,000, ~3,700 and ~9,500 SNPs explained ~21%, ~24% and ~29% of phenotypic variance. Furthermore, all common variants together captured the majority (60%) of heritability. The 697 variants clustered in 423 loci enriched for genes, pathways, and tissue-types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/beta-catenin, and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Solution-Processed MoS2/Organolead Trihalide Perovskite Photodetectors
Integration of organic/inorganic hybridperovskites with metallic or semiconducting phases of 2D MoS2 nanosheets via solution processing is demonstrated. The results show that the collection of charge carriers is strongly dependent on the electronic properties of the 2D MoS2 with metallic MoS2 showing high responsivity and the semiconducting phase exhibiting high on/off ratios