Publications by authors named "Jennifer N Nguyen"

Purpose: Single passive limb movement (sPLM) of the lower extremity is a simple and clinically relevant measure of the microvascular vasodilatory response to movement. A promising stimulus to improve microvascular health is ischemic conditioning (IC). We examined whether a single session of IC could improve microvascular reactivity to sPLM in young adults.

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Understanding post-stroke changes in skeletal muscle oxidative metabolism and microvascular reactivity could help create therapeutic targets that optimize rehabilitative interventions. Due to disuse atrophy, we hypothesized that basal muscle oxygen consumption rate and microvascular endothelial function would be impaired in the tibialis anterior (TA) muscle of the affected leg of chronic stroke survivors compared with the nonaffected leg and versus matched controls. Fifteen chronic stroke survivors (10 females) and 15 matched controls (9 females) completed this study.

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Background: Few studies have examined changes in skeletal muscle physiology post-stroke. This study examined changes in tissue oxygen saturation (StO) of the vastus lateralis (VL) muscle of stroke survivors and age-matched control participants during maximal and submaximal isometric contractions of the knee extensor muscles.

Objectives: We hypothesized that tissue oxygen desaturation (ΔStO) during knee extensor muscle contractions would be less in the VL in the paretic vs.

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Article Synopsis
  • This study investigated tissue oxygen saturation (StO) in the vastus lateralis (VL) muscles of stroke survivors during a graded exercise test (GXT), hypothesizing that the paretic VL would have less reduction in StO than the non-paretic VL.
  • Twenty-six chronic stroke survivors underwent a GXT while StO was measured using near infrared spectroscopy; results showed no initial difference in StO at rest between the paretic and non-paretic VL, but a significantly greater decrease in StO during the GXT in the non-paretic VL.
  • The findings indicate that oxygen desaturation is less pronounced in the paretic VL during intense exercise, and highlight a positive correlation between the oxygen desaturation response in the
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Introduction: This study investigated whether a novel therapy called ischemic conditioning (IC) improves walking capacity and lower extremity muscle performance in patients with peripheral vascular disease who experience intermittent claudication.

Methods: Forty-three patients with claudication were enrolled and received either IC or IC Sham for 2 weeks in this randomized, controlled, double-blinded, prospective study. IC sessions involved five cycles of alternating 5-min inflations of a blood pressure cuff to 225 mm Hg (25 mm Hg for IC Sham) and 5-min deflations, around the thigh of the affected lower extremity.

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Methylation integrates factors present at birth and modifiable across the lifespan that can influence pulmonary function. Studies are limited in scope and replication. To conduct large-scale epigenome-wide meta-analyses of blood DNA methylation and pulmonary function.

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Genome-wide association studies (GWASs) have identified regions associated with chronic obstructive pulmonary disease (COPD). GWASs of other diseases have shown an approximately 10-fold overrepresentation of nonsynonymous variants, despite limited exonic coverage on genotyping arrays. We hypothesized that a large-scale analysis of coding variants could discover novel genetic associations with COPD, including rare variants with large effect sizes.

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This study quantified stroke-related changes in the following: (1) the averaged discharge rate of motor units (individually tracked and untracked) identified from high-density electromyography (HD-EMG) recordings, (2) global muscle EMG properties of the dorsiflexors during a fatiguing contraction, and the relationship between task endurance and measures of leg function. Ten individuals with chronic stroke performed a sustained sub-maximal, isometric, fatiguing dorsiflexion contraction in paretic and non-paretic legs. Motor-unit firing behavior, task duration, maximal voluntary contraction strength (MVC), and clinical measures of leg function were obtained.

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Many stroke survivors have reduced cardiorespiratory fitness as a result of their stroke. Ischemic conditioning (IC) is a noninvasive, cost-effective, easy-to-administer intervention that can be performed at home and has been shown to improve both motor function in stroke survivors and vascular endothelial function in healthy individuals. In this study, we examined the effects of 2 wk of remote IC (RIC) on brachial artery flow mediated dilation (FMD) in chronic stroke survivors.

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Chronic obstructive pulmonary disease (COPD) has been associated with numerous genetic variants, yet the extent to which its genetic risk is mediated by variation in lung structure remains unknown. To characterize associations between a genetic risk score (GRS) associated with COPD susceptibility and lung structure on computed tomography (CT). We analyzed data from MESA Lung (Multi-Ethnic Study of Atherosclerosis Lung Study), a U.

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This pilot study examined whether ischemic conditioning (IC), a noninvasive, cost-effective, and easy-to-administer intervention, could improve gait speed and paretic leg muscle function in stroke survivors. We hypothesized that 2 wk of IC training would increase self-selected walking speed, increase paretic muscle strength, and reduce neuromuscular fatigability in chronic stroke survivors. Twenty-two chronic stroke survivors received either IC or IC Sham on their paretic leg every other day for 2 wk (7 total sessions).

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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.

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Rationale: Large airway dimensions on computed tomography (CT) have been associated with lung function, symptoms, and exacerbations in chronic obstructive pulmonary disease (COPD), as well as with symptoms in smokers with preserved spirometry. Their prognostic significance in persons without lung disease remains undefined.

Objectives: To examine associations between large airway dimensions on CT and respiratory outcomes in a population-based cohort of adults without prevalent lung disease.

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Susceptibility to chronic obstructive pulmonary disease (COPD) beyond cigarette smoking is incompletely understood, although several genetic variants associated with COPD are known to regulate airway branch development. We demonstrate that in vivo central airway branch variants are present in 26.5% of the general population, are unchanged over 10 y, and exhibit strong familial aggregation.

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Background: We conducted a genome-wide association study (GWAS) of subclinical interstitial lung disease (ILD), defined as high attenuation areas (HAA) on CT, in the population-based Multi-Ethnic Study of Atherosclerosis Study.

Methods: We measured the percentage of high attenuation areas (HAA) in the lung fields on cardiac CT scan defined as voxels with CT attenuation values between -600 and -250 HU. Genetic analyses were performed in MESA combined across race/ethnic groups: non-Hispanic White (n = 2,434), African American (n = 2,470), Hispanic (n = 2,065) and Chinese (n = 702), as well as stratified by race/ethnicity.

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We have adapted a bacterial CRISPR RNA/Cas9 system to precisely engineer the Drosophila genome and report that Cas9-mediated genomic modifications are efficiently transmitted through the germline. This RNA-guided Cas9 system can be rapidly programmed to generate targeted alleles for probing gene function in Drosophila.

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