Publications by authors named "Hanfelt J"

Objective: To evaluate the impact of receptive vocabulary versus years of education on neuropsychological performance of Black and White older adults.

Method: A community-based prospectively enrolled cohort ( = 1,007; 130 Black, 877 White) in the Emory Healthy Brain Study were administered the NIH Toolbox Picture Vocabulary Test and neuropsychological measures. Group differences were evaluated with age, sex, and education or age, sex, and Toolbox Vocabulary scores as covariates to determine whether performance differences between Black versus White participants were attenuated or eliminated.

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Objective: Alzheimer's disease (AD) is believed to be more common in African Americans (AA), but biomarker studies in AA populations are limited. This report represents the largest study to date examining cerebrospinal fluid AD biomarkers in AA individuals.

Methods: We analyzed 3,006 cerebrospinal fluid samples from controls, AD cases, and non-AD cases, including 495 (16.

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There is no gold standard for the diagnosis of Alzheimer's disease (AD), except from autopsies, which motivates the use of unsupervised learning. A mixture of regressions is an unsupervised method that can simultaneously identify clusters from multiple biomarkers while learning within-cluster demographic effects. Cerebrospinal fluid (CSF) biomarkers for AD have detection limits, which create additional challenges.

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Background: Although there are many possible causes for cervical dystonia (CD), a specific etiology cannot be identified in most cases. Prior studies have suggested a relationship between autoimmune disease and some cases of CD, pointing to possible immunological mechanisms.

Objective: The goal was to explore the potential role of multiple different immunological mechanisms in CD.

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Heterogeneous survival data are commonly present in chronic disease studies. Delineating meaningful disease subtypes directly linked to a survival outcome can generate useful scientific implications. In this work, we develop a latent class proportional hazards (PH) regression framework to address such an interest.

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Alzheimer's disease (AD) progresses through a lengthy asymptomatic period during which pathological changes accumulate prior to development of clinical symptoms. As disease-modifying treatments are developed, tools to stratify risk of clinical disease will be required to guide their use. In this study, we examine the relationship of AD biomarkers in healthy middle-aged individuals to health history, family history, and neuropsychological measures and identify cerebrospinal fluid (CSF) biomarkers to stratify risk of progression from asymptomatic to symptomatic AD.

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There are many possible etiologies for cervical dystonia (CD), but a cause cannot be identified in most cases. Most recent attention has focused on genetic causes, although a few prior studies have highlighted autoimmune mechanisms instead. Because autoimmune disorders frequently co-exist, the current study evaluated the hypothesis that autoimmune disorders might be more common in CD than neurological controls.

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Recurrent events data frequently arise in chronic disease studies, providing rich information on disease progression. The concept of latent class offers a sensible perspective to characterize complex population heterogeneity in recurrent event trajectories that may not be adequately captured by a single regression model. However, the development of latent class methods for recurrent events data has been sparse, typically requiring strong parametric assumptions and involving algorithmic issues.

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Objective: To explore the heterogeneity of neuropsychiatric symptom (NPS) complexes in individuals with mild cognitive impairment (MCI) and assess the relative risks of converting to dementia or dying.

Design: Latent class analysis using 7,971 participants with MCI.

Setting: Participants in the Uniform Data Set (UDS) from 39 NIH Alzheimer's Disease Centers.

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The locus coeruleus is the initial site of Alzheimer's disease neuropathology, with hyperphosphorylated Tau appearing in early adulthood followed by neurodegeneration in dementia. Locus coeruleus dysfunction contributes to Alzheimer's pathobiology in experimental models, which can be rescued by increasing norepinephrine transmission. To test norepinephrine augmentation as a potential disease-modifying therapy, we performed a biomarker-driven phase II trial of atomoxetine, a clinically-approved norepinephrine transporter inhibitor, in subjects with mild cognitive impairment due to Alzheimer's disease.

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Latent class analysis is an intuitive tool to characterize disease phenotype heterogeneity. With data more frequently collected on multiple phenotypes in chronic disease studies, it is of rising interest to investigate how the latent classes embedded in one phenotype are related to another phenotype. Motivated by a cohort with mild cognitive impairment (MCI) from the Uniform Data Set (UDS), we propose and study a time-dependent structural model to evaluate the association between latent classes and competing risk outcomes that are subject to missing failure types.

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Belatacept results in improved kidney transplant outcomes, but utilization has been limited by logistical barriers related to monthly (q1m) intravenous infusions. Every 2-month (q2m) belatacept has potential to increase utilization, therefore we conducted a randomized noninferiority trial in low immunologic risk renal transplant recipients greater than 1-year posttransplant. Patients on belatacept were randomly assigned to q1m or q2m therapy.

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Latent trajectory class analysis is a powerful technique to elucidate the structure underlying population heterogeneity. The standard approach relies on fully parametric modeling and is computationally impractical when the data include a large collection of non-Gaussian longitudinal features. We introduce a new approach, the first based on artificial likelihood concepts, that avoids undue modeling assumptions and is computationally tractable.

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Background: Recent reports have demonstrated that among patients with subarachnoid hemorrhage (SAH) treated with hypertonic NaCl, resultant hyperchloremia has been associated with the development of acute kidney injury (AKI). We report a trial comparing the effect of two hypertonic solutions with different chloride contents on the resultant serum chloride concentrations in SAH patients, with a primary outcome aimed at limiting chloride elevation.

Methods: A low ChloridE hyperTonic solution for brain Edema (ACETatE) trial is a single-center, double-blinded, double-dummy, randomized pilot trial comparing bolus infusions of 23.

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Understanding the relationships between health and aging is essential for delaying morbidity and maximizing independence in aging populations as life expectancies increase. Loss of cognitive function is a feared age-associated condition and growing public health concern. Alzheimer's disease (AD), the most common cause of dementia, has no curative therapies.

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Objective: Subjective memory complaints (SMCs) are associated with mild cognitive impairment and dementia but are understudied in African Americans (AAs). We compared SMC endorsement in white and AA participants and evaluated predictors of diagnostic progression.

Methods: Initial visit variables, including SMC and memory performance, were compared within a cognitively normal race-matched sample of white and AA participants ( = 912; 456) to assess the presence and predictors of SMC, the predictors of future diagnostic progression, and the change in memory performance over time.

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Background Higher symptom levels of a variety of measures of emotional distress have been associated with cardiovascular disease ( CVD ), especially among women. Here, our goal was to investigate the association between a composite measure of psychological distress and incident cardiovascular events. Methods and Results In a prospective cohort study, we assessed 662 individuals (28% women; 30% blacks) with stable coronary artery disease.

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Objective: Mental stress-induced myocardial ischemia is a frequent phenomenon in patients with coronary artery disease (CAD). The link between an integrated measure of chronic psychosocial distress and mental stress-induced myocardial ischemia, and whether it differs by sex, has not been examined before.

Methods: We used latent class analysis to derive a composite measure of psychosocial distress integrating scales of depression, posttraumatic stress, anxiety, anger, hostility, and perceived stress in 665 individuals with stable CAD.

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Background: Aneurysmal subarachnoid hemorrhage (aSAH) is a life-threatening condition that results from a ruptured cerebral vessel. Cerebral edema and vasospasm are common complications and frequently require treatment with hypertonic solutions, in particular hypertonic sodium chloride (NaCl). We have previously shown that hyperchloremia in patients with aSAH given hypertonic NaCl is associated with the development of acute kidney injury (AKI), which leads to higher morbidity and mortality.

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Given the importance of identifying prodromes of dementia with specific etiologies, we assessed whether seven latent classes of mild cognitive impairment (MCI), defined empirically based on cognitive, functional, and neuropsychiatric information at initial visit, are associated with distinct clinical outcomes and neuropathological features. We separated 6034 participants with a baseline diagnosis of MCI into seven latent classes using previously defined criteria. We found that these latent classes of MCI differed significantly in their clinical outcomes, survival time, and neuropathology.

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Oromandibular dystonia (OMD) causes involuntary movements of masticatory and lingual muscles impairing eating, speaking, and swallowing. Treatment options are limited. The objective of this study was to determine the safety and efficacy of abobotulinumtoxinA (aboBoNTA) in OMD.

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Context: Disruption of gut microbiota may exacerbate severity of cystic fibrosis (CF). Vitamin D deficiency is a common comorbidity in patients with CF that may influence composition of the gut microbiota.

Objectives: Compare microbiota of vitamin D-sufficient and -insufficient CF patients and assess impact of a weekly high-dose vitamin D3 bolus regimen on gut and airway microbiome in adults with CF and vitamin D insufficiency (25-hydroxyvitamin D < 30 ng/mL).

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