26 research outputs found
Int J Tuberc Lung Dis
BackgroundTherapeutic effects of antiretroviral therapy (ART) in patients with multidrug resistant tuberculosis (MDR-TB) and HIV infection have not been established.ObjectiveThe objective of this study was to assess therapeutic outcomes of ART integration with MDR-TB treatment.DesignA subgroup of MDR-TB patients from the SAPiT study, a randomized controlled trial, conducted in an out-patient clinic in Durban, South Africa from 2008\u20132012MethodsClinical outcomes at 18 months were compared in patients randomized to receive ART within 12 weeks of standard first-line tuberculosis treatment initiation with those who commenced ART after completing tuberculosis treatment.ResultsMycobacterium tuberculosis drug susceptibility was available in 489 (76%) of 642 SAPiT patients; 23 had MDR-TB, 14 in the integrated treatment arm and 9 in the sequential treatment arm. At 18 months, the mortality rate was 11.9/100 person-years (95% confidence interval (CI): 1.4\u201342.8) in the combined integrated treatment arm and 56.0/100 person-years (95%CI: 18.2\u2013130.8) in the sequential treatment arm, (Hazard Ratio adjusted for baseline CD4 count and whether MDR-TB treatment was initiated: 0.14; 95% CI: 0.02\u20130.94; P=0.04).ConclusionDespite the small sample size, the 86% reduction in mortality due to early initiation of ART in MDR-TB patients was statistically significant.D43TW00231/TW/FIC NIH HHS/United StatesD43 TW000231/TW/FIC NIH HHS/United States5U26PS001350/PS/NCHHSTP CDC HHS/United StatesU19 AI051794/AI/NIAID NIH HHS/United StatesU2G PS001350/PS/NCHHSTP CDC HHS/United StatesPEPFAR/United States2016-02-29T00:00:00Z24429305PMC47700138583vault:1580
Albuminuria, lung function decline, and risk of incident chronic obstructive pulmonary disease the NHLBI pooled cohorts study
Rationale: Chronic lower respiratory diseases (CLRDs), including chronic obstructive pulmonary disease (COPD) and asthma, are the fourth leading cause of death. Prior studies suggest that albuminuria, a biomarker of endothelial injury, is increased in patients with COPD. Objectives: To test whether albuminuria was associated with lung function decline and incident CLRDs. Methods: Six U.S. population–based cohorts were harmonized and pooled. Participants with prevalent clinical lung disease were excluded. Albuminuria (urine albumin-to-creatinine ratio) was measured in spot samples. Lung function was assessed by spirometry. Incident CLRD-related hospitalizations and deaths were classified via adjudication and/or administrative criteria. Mixed and proportional hazards models were used to test individual-level associations adjusted for age, height, weight, sex, race/ethnicity, education, birth year, cohort, smoking status, pack-years of smoking, renal function, hypertension, diabetes, and medications. Measurements and Main Results: Among 10,961 participants with preserved lung function, mean age at albuminuria measurement was 60 years, 51% were never-smokers, median albuminuria was 5.6 mg/g, and mean FEV 1 decline was 31.5 ml/yr. For each SD increase in log-transformed albuminuria, there was 2.81% greater FEV 1 decline (95% confidence interval [CI], 0.86–4.76%; P = 0.0047), 11.02% greater FEV 1 /FVC decline (95% CI, 4.43–17.62%; P = 0.0011), and 15% increased hazard of incident spirometry-defined moderate-to-severe COPD (95% CI, 2–31%, P = 0.0021). Each SD log-transformed albuminuria increased hazards of incident COPD-related hospitalization/mortality by 26% (95% CI, 18–34%, P, 0.0001) among 14,213 participants followed for events. Asthma events were not significantly associated. Associations persisted in participants without current smoking, diabetes, hypertension, or cardiovascular disease. Conclusions: Albuminuria was associated with greater lung function decline, incident spirometry-defined COPD, and incident COPD-related events in a U.S. population–based sample
Lung function decline in former smokers and low-intensity current smokers: a secondary data analysis of the NHLBI Pooled Cohorts Study
Background: Former smokers now outnumber current smokers in many developed countries, and current smokers are smoking fewer cigarettes per day. Some data suggest that lung function decline normalises with smoking cessation; however, mechanistic studies suggest that lung function decline could continue. We hypothesised that former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers, including among those without prevalent lung disease. Methods: We used data on six US population-based cohorts included in the NHLBI Pooled Cohort Study. We restricted the sample to participants with valid spirometry at two or more exams. Two cohorts recruited younger adults (≥17 years), two recruited middle-aged and older adults (≥45 years), and two recruited only elderly adults (≥65 years) with examinations done between 1983 and 2014. FEV1 decline in sustained former smokers and current smokers was compared to that of never-smokers by use of mixed models adjusted for sociodemographic and anthropometric factors. Differential FEV1 decline was also evaluated according to duration of smoking cessation and cumulative (number of pack-years) and current (number of cigarettes per day) cigarette consumption. Findings: 25 352 participants (ages 17–93 years) completed 70 228 valid spirometry exams. Over a median follow-up of 7 years (IQR 3–20), FEV1 decline at the median age (57 years) was 31·01 mL per year (95% CI 30·66–31·37) in sustained never-smokers, 34·97 mL per year (34·36–35·57) in former smokers, and 39·92 mL per year (38·92–40·92) in current smokers. With adjustment, former smokers showed an accelerated FEV1 decline of 1·82 mL per year (95% CI 1·24–2·40) compared to never-smokers, which was approximately 20% of the effect estimate for current smokers (9·21 mL per year; 95% CI 8·35–10·08). Compared to never-smokers, accelerated FEV1 decline was observed in former smokers for decades after smoking cessation and in current smokers with low cumulative cigarette consumption (<10 pack-years). With respect to current cigarette consumption, the effect estimate for FEV1 decline in current smokers consuming less than five cigarettes per day (7·65 mL per year; 95% CI 6·21–9·09) was 68% of that in current smokers consuming 30 or more cigarettes per day (11·24 mL per year; 9·86–12·62), and around five times greater than in former smokers (1·57 mL per year; 1·00–2·14). Among participants without prevalent lung disease, associations were attenuated but were consistent with the main results. Interpretation: Former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers. These results suggest that all levels of smoking exposure are likely to be associated with lasting and progressive lung damage. Funding: National Institutes of Health, National Heart Lung and Blood Institute, and US Environmental Protection Agency
Particle acceleration mechanisms
We review the possible mechanisms for production of non-thermal electrons
which are responsible for non-thermal radiation in clusters of galaxies. Our
primary focus is on non-thermal Bremsstrahlung and inverse Compton scattering,
that produce hard X-ray emission. We briefly review acceleration mechanisms and
point out that in most astrophysical situations, and in particular for the
intracluster medium, shocks, turbulence and plasma waves play a crucial role.
We consider two scenarios for production of non-thermal radiation. The first is
hard X-ray emission due to non-thermal Bremsstrahlung by nonrelativistic
particles. Non-thermal tails are produced by accelerating electrons from the
background plasma with an initial Maxwellian distribution. However, these tails
are accompanied by significant heating and they are present for a short time of
<10^6 yr, which is also the time that the tail will be thermalised. Such
non-thermal tails, even if possible, can only explain the hard X-ray but not
the radio emission which needs GeV or higher energy electrons. For these and
for production of hard X-rays by the inverse Compton model, we need the second
scenario where there is injection and subsequent acceleration of relativistic
electrons. It is shown that a steady state situation, for example arising from
secondary electrons produced from cosmic ray proton scattering by background
protons, will most likely lead to flatter than required electron spectra or it
requires a short escape time of the electrons from the cluster. An episodic
injection of relativistic electrons, presumably from galaxies or AGN, and/or
episodic generation of turbulence and shocks by mergers can result in an
electron spectrum consistent with observations but for only a short period of
less than one billion years.Comment: 22 pages, 5 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 11; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study
Aims: The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF). Methods and results: Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC ≥0.70, FVC <80%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50%) or preserved EF (HFpEF; EF ≥50%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking. Conclusion: Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors
Harmonization of Respiratory Data from 9 US Population-Based Cohorts
Chronic lower respiratory diseases (CLRDs) are the fourth leading cause of death in the United States. To support investigations into CLRD risk determinants and new approaches to primary prevention, we aimed to harmonize and pool respiratory data from US general population-based cohorts. Data were obtained from prospective cohorts that performed prebronchodilator spirometry and were harmonized following 2005 ATS/ERS standards. In cohorts conducting follow-up for noncardiovascular events, CLRD events were defined as hospitalizations/deaths adjudicated as CLRDrelated or assigned relevant administrative codes. Coding and variable names were applied uniformly. The pooled sample included 65,251 adults in 9 cohorts followed-up for CLRD-related mortality over 653,380 person-years during 1983-2016. Average baseline age was 52 years; 56% were female; 49% were never-smokers; and racial/ethnic composition was 44% white, 22% black, 28% Hispanic/Latino, and 5% American Indian. Over 96% had complete data on smoking, clinical CLRD diagnoses, and dyspnea. After excluding invalid spirometry examinations (13%), there were 105,696 valid examinations (median, 2 per participant). Of 29,351 participants followed for CLRD hospitalizations, median follow-up was 14 years; only 5% were lost to follow-up at 10 years. The NHLBI Pooled Cohorts Study provides a harmonization standard applied to a large, US population-based sample that may be used to advance epidemiologic research on CLRD
Genome-Wide Joint Meta-Analysis of SNP and SNP-by-Smoking Interaction Identifies Novel Loci for Pulmonary Function
Multiethnic meta-analysis identifies ancestry-specific and cross-ancestry loci for pulmonary function
Nearly 100 loci have been identified for pulmonary function, almost exclusively in studies of European ancestry populations. We extend previous research by meta-analyzing genome-wide association studies of 1000 Genomes imputed variants in relation to pulmonary function in a multiethnic population of 90,715 individuals of European (N = 60,552), African (N = 8429), Asian (N = 9959), and Hispanic/Latino (N = 11,775) ethnicities. We identify over 50 additional loci at genome-wide significance in ancestry-specific or multiethnic meta-analyses. Using recent fine-mapping methods incorporating functional annotation, gene expression, and differences in linkage disequilibrium between ethnicities, we further shed light on potential causal variants and genes at known and newly identified loci. Several of the novel genes encode proteins with predicted or established drug targets, including KCNK2 and CDK12. Our study highlights the utility of multiethnic and integrative genomics approaches to extend existing knowledge of the genetics of l
Rare and low-frequency exonic variants and gene-by-smoking interactions in pulmonary function
Genome-wide association studies have identified numerous common genetic variants associated with spirometric measures of pulmonary function, including forced expiratory volume in one second (FEV1), forced vital capacity, and their ratio. However, variants with lower minor allele frequencies are less explored. We conducted a large-scale gene-smoking interaction meta-analysis on exonic rare and low-frequency variants involving 44,429 individuals of European ancestry in the discovery stage and sought replication in the UK BiLEVE study with 45,133 European ancestry samples and UK Biobank study with 59,478 samples. We leveraged data on cigarette smoking, the major environmental risk factor for reduced lung function, by testing gene-by-smoking interaction effects only and simultaneously testing the genetic main effects and interaction effects. The most statistically significant signal that replicated was a previously reported low-frequency signal in GPR126, distinct from common variant associations in this gene. Although only nominal replication was obtained for a top rare variant signal rs142935352 in one of the two studies, interaction and joint tests for current smoking and PDE3B were significantly associated with FEV1. This study investigates the utility of assessing gene-by-smoking interactions and underscores their effects on potential pulmonary function.Clinical epidemiolog