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537 citation(s) found for "Walker, J C".

Medication-Assisted Treatment for Opioid Use Disorder in a Rural Family Medicine Practice
Deyo-Svendsen, Mark , Svendsen, Matthew Cabrera, Hodges, Andrea, Oldfather, Rachel Z., Mansukhani, Meghna P. , Cabrera Svendsen, Matthew, Walker, James, Mansukhani, Meghna P , Deyo-Svendsen, Mark E , Walker, James E.

Journal of Primary Care & Community Health | June 6, 2020 | Volume: 11 | Issue: No issue available | Pages: No page available

10.1177/2150132720931720 | PMID 32507023 Get It

Opioid use disorder (OUD) is a cause of significant morbidity and mortality in the United States. Although efforts are being made to limit access to prescription opioids, the use of heroin and synthetic opioids as well as death due to opioid overdose has increased. Medication-assisted treatment (MAT) is the pairing of psychosocial intervention with a Food and Drug Administration (FDA)–approved medication (methadone, buprenorphine plus naltrexone) to treat OUD. MAT has resulted in reductions in overdose deaths, criminal activity, and infectious disease transmission. Access to MAT in rural areas is limited by shortages of addiction medicine-trained providers, lack of access to comprehensive addiction programs, transportation, and cost-related issues. Rural physicians express concern about lack of mentorship and drug diversion as reasons to avoid MAT. The prescribing of MAT with buprenorphine requires a Drug Enforcement Agency (DEA) waiver that can easily be obtained by Family Medicine providers. MAT can be incorporated into the outpatient practice, where patient follow-up rates and number needed to treat to effect change are similar to that of other chronic medical conditions. We describe a case of opioid overdose and a suggested protocol for the induction of MAT with buprenorphine/naloxone (Suboxone) for OUD in a rural family medicine outpatient practice. Treatment access is facilitated by utilizing the protocol, allowing office staff work to the extent allowed by their licensure, promoting teamwork and minimizing physician time commitment. We conclude that improved access to MAT can be accomplished in a rural family medicine outpatient clinic by staff that support and mentor one another through use of a MAT protocol.
Delayed presentation of acute ischemic strokes during the COVID-19 crisis
Schirmer, Clemens M. , Ringer, Andrew J. , Binning, Mandy J., Fox, W. Christopher , James, Robert F. , Levitt, Michael R. , Veznedaroglu, Erol, Walker, Melanie , Spiotta, Alejandro M , Arthur, Adam Stephen , Levitt, Michael R , Fox, W Christopher , Schirmer, Clemens M , Tawk, Rabih G.

Journal of NeuroInterventional Surgery | May 28, 2020 | Volume: 12 | Issue: 7 | Pages: 639-642

10.1136/neurintsurg-2020-016299 | PMID 32467244 Get It

Background The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US. Methods The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020. Results There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02). Conclusion We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center.
Mid- and Late-Life Leisure-Time Physical Activity and Global Brain Amyloid Burden: The Atherosclerosis Risk in Communities (ARIC)-PET Study
Palta, Priya, Heiss, Gerardo , Sharrett, A. Richey, Gabriel, Kelley Pettee , Evenson, Kelly R. , Wong, Dean F. , Walker, Keenan A. , Knopman, David S. , Mosley, Thomas H. , Gottesman, Rebecca F.

Journal of Alzheimer's Disease | May 22, 2020 | Volume: 76 | Issue: 1 | Pages: 139-147

10.3233/jad-200152 | PMID 32444546 Get It

A hybrid echocardiography‐CFD framework for ventricular flow simulations
Hedayat, Mohammadali, Patel, Tatsat R., Kim, Taeouk, Belohlavek, Marek, Hoffmann, Kenneth R., Borazjani, Iman , Hedayat, Mohammadali, Patel, Tatsat R., Kim, Taeouk, Belohlavek, Marek, Hoffmann, Kenneth R., Borazjani, Iman

International Journal for Numerical Methods in Biomedical Engineering | May 18, 2020 | Volume: 36 | Issue: 7 | Pages: No page available

10.1002/cnm.3352 | PMID 32419374 Get It

AbstractImage‐based CFD is a powerful tool to study cardiovascular flows while 2D echocardiography (echo) is the most widely used noninvasive imaging modality for the diagnosis of heart disease. Here, echo is combined with CFD, that is, an echo‐CFD framework, to study ventricular flows. To achieve this, the previous 3D reconstruction from multiple 2D echo at standard cross sections is extended by: (a) reconstructing aortic and mitral valves from 2D echo and closing the left‐ventricle (LV) geometry by approximating a superior wall; (b) incorporating the physiological assumption of the fixed apex as a reference (fixed) point in the 3D reconstruction; and (c) incorporating several smoothing algorithms to remove the nonphysical oscillations (ringing) near the basal section. The method is applied to echo from a baseline LV and one after inducing acute myocardial ischemia (AMI). The 3D reconstruction is validated by comparing it against a reference reconstruction from many echo sections while flow simulations are validated against the Doppler ultrasound velocity measurements. The sensitivity study shows that the choice of the smoothing algorithm does not change the flow pattern inside the LV. However, the presence of the mitral valve can significantly change the flow pattern during the diastole phase. In addition, the abnormal shape of a LV with AMI can drastically change the flow during diastole. Furthermore, the hemodynamic energy loss, as an indicator of the LV pumping performance, for different test cases is calculated, which shows a larger energy loss for a LV with AMI compared to the baseline one.
Association Between Blood Pressure and Later-Life Cognition Among Black and White Individuals
Levine, Deborah A. , Gross, Alden L. , Briceño, Emily M. , Tilton, Nicholas , Kabeto, Mohammed U. , Hingtgen, Stephanie, Giordani, Bruno , Sussman, Jeremy B. , Hayward, Rodney A. , Burke, James , Elkind, Mitchell S.V. , Kulick, Erin R. , Yano, Yuichiro , Gaskin, Darrell J. , Sidney, Stephen , Yaffe, Kristine , Sacco, Ralph L., Roger, Véronique L. , Allen, Norrina B. , Gałecki, Andrzej T. , Tilton, Nicholas, Manly, Jennifer J. , Moran, Andrew Edward , Gottesman, Rebecca F. , Walker, Keenan A. , Wright, Clinton B.

JAMA Neurology | April 13, 2020 | Volume: 77 | Issue: 7 | Pages: 810

10.1001/jamaneurol.2020.0568 | PMID 32282019 Get It

Importance Black individuals are more likely than white individuals to develop dementia. Whether higher blood pressure (BP) levels in black individuals explain differences between black and white individuals in dementia risk is uncertain. Objective To determine whether cumulative BP levels explain racial differences in cognitive decline. Design, Setting, and Participants Individual participant data from 5 cohorts (January 1971 to December 2017) were pooled from the Atherosclerosis Risk in Communities Study, Coronary Artery Risk Development in Young Adults Study, Cardiovascular Health Study, Framingham Offspring Study, and Northern Manhattan Study. Outcomes were standardized as t scores (mean [SD], 50 [10]); a 1-point difference represented a 0.1-SD difference in cognition. The median (interquartile range) follow-up was 12.4 (5.9-21.0) years. Analysis began September 2018. Main Outcomes and Measures The primary outcome was change in global cognition, and secondary outcomes were change in memory and executive function. Exposures Race (black vs white). Results Among 34 349 participants, 19 378 individuals who were free of stroke and dementia and had longitudinal BP, cognitive, and covariate data were included in the analysis. The mean (SD) age at first cognitive assessment was 59.8 (10.4) years and ranged from 5 to 95 years. Of 19 378 individuals, 10 724 (55.3%) were female and 15 526 (80.1%) were white. Compared with white individuals, black individuals had significantly faster declines in global cognition (−0.03 points per year faster [95% CI, −0.05 to −0.01]; P = .004) and memory (−0.08 points per year faster [95% CI, −0.11 to −0.06]; P &amp;lt; .001) but significantly slower declines in executive function (0.09 points per year slower [95% CI, 0.08-0.10]; P &amp;lt; .001). Time-dependent cumulative mean systolic BP level was associated with significantly faster declines in global cognition (−0.018 points per year faster per each 10–mm Hg increase [95% CI, −0.023 to −0.014]; P &amp;lt; .001), memory (−0.028 points per year faster per each 10–mm Hg increase [95% CI, −0.035 to −0.021]; P &amp;lt; .001), and executive function (−0.01 points per year faster per each 10–mm Hg increase [95% CI, −0.014 to −0.007]; P &amp;lt; .001). After adjusting for cumulative mean systolic BP, differences between black and white individuals in cognitive slopes were attenuated for global cognition (−0.01 points per year [95% CI, −0.03 to 0.01]; P = .56) and memory (−0.06 points per year [95% CI, −0.08 to −0.03]; P &amp;lt; .001) but not executive function (0.10 points per year [95% CI, 0.09-0.11]; P &amp;lt; .001). Conclusions and Relevance These results suggest that black individuals’ higher cumulative BP levels may contribute to racial differences in later-life cognitive decline.
Phosphoric Metabolites Link Phosphate Import and Polysaccharide Biosynthesis for Candida albicans Cell Wall Maintenance
Liu, Ning‐Ning , Acosta‐Zaldívar, Maikel , Qi, Wanjun , Diray‐Arce, Joann , Kelly, R, Yuan, Min , Lasky‐Su, Jessica , Köhler, Julia R. , Walker, Louise A , Kottom, Theodore J. , Lasky-Su, Jessica , Asara, John M. , Levy, Ofer , Limper, Andrew H. , Gow, Neil A. R.

mBio | March 16, 2020 | Volume: 11 | Issue: 2 | Pages: No page available

10.1128/mbio.03225-19 | PMID 32184254 Get It

Candida species cause hundreds of thousands of invasive infections with high mortality each year. Developing novel antifungal agents is challenging due to the many similarities between fungal and human cells. Maintaining phosphate balance is essential for all organisms but is achieved completely differently by fungi and humans. A protein that imports phosphate into fungal cells, Pho84, is not present in humans and is required for normal cell wall stress resistance and cell wall integrity signaling in C. albicans . Nucleotide sugars, which are phosphate-containing building block molecules for construction of the cell wall, are diminished in cells lacking Pho84. Cell wall-constructing enzymes may be slowed by lack of these building blocks, in addition to being inhibited by drugs. Combined targeting of Pho84 and cell wall-constructing enzymes may provide a strategy for antifungal therapy by which two sequential steps of cell wall maintenance are blocked for greater potency.
Aortic Stiffness and White Matter Microstructural Integrity Assessed by Diffusion Tensor Imaging: The ARIC‐NCS
Wei, Jingkai , Palta, Priya, Kucharska‐Newton, Anna , Pence, Brian W. , Aiello, Allison E. , Sharrett, A. Richey, Tanaka, Hirofumi , Reyes, Denise A., Heiss, Gerardo , Kucharska-Newton, Anna M , Meyer, Michelle L. , Power, Melinda C. , Walker, Keenan A. , Jack, Clifford R. , Mosley, Thomas H. , Reid, Robert I.

Journal of the American Heart Association | March 11, 2020 | Volume: 9 | Issue: 6 | Pages: No page available

10.1161/jaha.119.014868 | PMID 32157957 Get It

Background Changes in white matter microstructural integrity are detectable before appearance of white matter lesions on magnetic resonance imaging as a manifestation of cerebral small‐vessel disease. The information relating poor white matter microstructural integrity to aortic stiffness, a hallmark of aging, is limited. We aimed to examine the association between aortic stiffness and white matter microstructural integrity among older adults. Methods and Results We conducted a cross‐sectional study to examine the association between aortic stiffness and white matter microstructural integrity among 1484 men and women (mean age, 76 years) at the 2011 to 2013 examination of the ARIC‐NCS (Atherosclerosis Risk in Communities Neurocognitive Study). Aortic stiffness was measured as carotid‐femoral pulse wave velocity. Cerebral white matter microstructural integrity was measured as fractional anisotropy and mean diffusivity using diffusion tensor imaging. Multivariable linear regression was used to examine the associations of carotid‐femoral pulse wave velocity with fractional anisotropy and mean diffusivity of the overall cerebrum and at regions of interest. Each 1‐m/s higher carotid‐femoral pulse wave velocity was associated with lower overall fractional anisotropy (β=−0.03; 95% CI , −0.05 to −0.02) and higher overall mean diffusivity (β=0.03; 95% CI , 0.02–0.04). High carotid‐femoral pulse wave velocity (upper 25th percentile) was associated with lower fractional anisotropy (β=−0.40; 95% CI , −0.61 to −0.20) and higher overall mean diffusivity (β=0.27; 95% CI , 0.10–0.43). Similar associations were observed at individual regions of interest. Conclusions High aortic stiffness is associated with low cerebral white matter microstructural integrity among older adults. Aortic stiffness may serve as a target for the prevention of poor cerebral white matter microstructural integrity.
Abstract 01: Retinal Microvascular Signs and White Matter MRI Findings: The Atherosclerosis Risk in Communities Neurocognitive Study
Bandeen‐Roche, Karen , Griswold, Michael , Sharrett, A. Richey , Deal, Jennifer A. , Power, Melinda C. , Knopman, David S. , Mosley, Thomas H. , Walker, Keenan A. , Gottesman, Rebecca F.

Circulation | March 2, 2020 | Volume: 141 | Issue: Suppl_1 | Pages: No page available

10.1161/circ.141.suppl_1.01 Get It

Introduction: Cerebrovascular small vessel disease, seen on brain imaging as lacunes and white matter hyperintensities (WMH), is a substrate for dementia in older adults. Diffusion tensor imaging (DTI) is thought to provide early signs of loss of white matter (WM) integrity due to microvascular disease and predicts WM hyperintensity volume. Retinal fundus photography provides surrogate measures of cerebral microvasculature. No studies have quantified the long-term association between retinal signs and DTI measures. Hypothesis: Microvascular retinal signs measured in midlife are associated with small vessel disease measured on brain magnetic resonance imaging (MRI) 18 years later, including reduced WM microstructural integrity (lower fractional anisotrophy [FA] and greater mean diffusivity [MD] by DTI), greater WM hyperintensity volume and greater lacune prevalence. Methods: In a biracial prospective cohort study, retinal signs were measured using fundus photography (1993-1995) with 3-T magnetic resonance imaging conducted in 2011-13. Multivariable-adjusted linear regression was used to quantify the relationships of retinal signs with WM measures. Prevalence of lacunar infarcts by retinal sign status was estimated using log binomial regression. Analyses were adjusted for age [linear and quadratic terms], education, sex, race, intracranial volume, body mass index, smoking, diabetes, hypertension, and ≥1 APOE ε4 alleles. Results: In 1829 men and women (60% [N=1100] female, 27% [N=489] black race, aged 50-72 years when retinal signs were measured), a binary measure comprised of two retinal signs suggestive of arteriolar damage due to hypertension (focal arteriolar narrowing and/or arteriovenous nicking) was associated with worse (lower) FA (standardized β=-0.19, 95% confidence interval [CI]=-0.35, -0.02), worse (higher) MD (β=0.15, 95% CI=0.00, 0.30), greater WM hyperintensity volume (β=0.15, 95% CI=0.01, 0.30), and greater prevalence of lacunes (prevalence ratio=1.33, 95% CI: 0.99, 1.80). Generalized arteriolar narrowing, measured as the central retinal arteriolar equivalent (CRAE, narrowest quartile vs. widest three quartiles) was associated with worse FA (β=-0.13, 95% CI=-0.24, -0.01) and worse MD (β=0.12, 95% CI=0.01, 0.23). Results did not differ by sex, race, hypertension status or APOE ε4 genotype. No associations were found for retinopathy, but only 56 participants had retinopathy. Conclusions: Consistent with prior work, and as expected based on a common underlying pathology, retinal signs predicted WM disease and lacunar infarcts 18 years later. Novel to this study, we found that retinal signs related to arteriolar damage also predicted loss of white matter microvascular integrity measured using DTI.
Adipose‐Derived Biogenic Nanoparticles for Suppression of Inflammation
Tian, Ming , Ticer, Taylor , Walker, Sierra A. , Pham, Anthony , Suh, Annie, Busatto, Sara , Davidovich, Irina, Al‐kharboosh, Rawan , Lewis‐Tuffin, Laura J. , Ji, Baoan , Quiñones‐Hinojosa, Alfredo , Rückert, Felix , Wolfram, Joy , Wang, Qikun, Walker, Sierra, Al-Kharboosh, Rawan, Lewis-Tuffin, Laura, Wolfram, Joy , Wang, Qikun , Talmon, Yeshayahu , Shapiro, Shane A.

Small | February 18, 2020 | Volume: 16 | Issue: 10 | Pages: No page available

10.1002/smll.201904064 | PMID 32067382 Get It

Abstract Extracellular vesicles secreted from adipose‐derived mesenchymal stem cells (ADSCs) have therapeutic effects in inflammatory diseases. However, production of extracellular vesicles (EVs) from ADSCs is costly, inefficient, and time consuming. The anti‐inflammatory properties of adipose tissue‐derived EVs and other biogenic nanoparticles have not been explored. In this study, biogenic nanoparticles are obtained directly from lipoaspirate, an easily accessible and abundant source of biological material. Compared to ADSC‐EVs, lipoaspirate nanoparticles (Lipo‐NPs) take less time to process (hours compared to months) and cost less to produce (clinical‐grade cell culture facilities are not required). The physicochemical characteristics and anti‐inflammatory properties of Lipo‐NPs are evaluated and compared to those of patient‐matched ADSC‐EVs. Moreover, guanabenz loading in Lipo‐NPs is evaluated for enhanced anti‐inflammatory effects. Apolipoprotein E and glycerolipids are enriched in Lipo‐NPs compared to ADSC‐EVs. Additionally, the uptake of Lipo‐NPs in hepatocytes and macrophages is higher. Lipo‐NPs and ADSC‐EVs have comparable protective and anti‐inflammatory effects. Specifically, Lipo‐NPs reduce toll‐like receptor 4‐induced secretion of inflammatory cytokines in macrophages. Guanabenz‐loaded Lipo‐NPs further suppress inflammatory pathways, suggesting that this combination therapy can have promising applications for inflammatory diseases.