Publications by authors named "M Alexander"

3,084 Publications

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Reduction in left frontal alpha oscillations by transcranial alternating current stimulation in major depressive disorder is context-dependent in a randomized clinical trial.

Biol Psychiatry Cogn Neurosci Neuroimaging 2021 Jul 14. Epub 2021 Jul 14.

Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC; Carolina Center for Neurostimulation, University of North Carolina at Chapel Hill, Chapel Hill, NC; Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC; Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC. Electronic address:

Background: Left frontal alpha oscillations are associated with decreased approach motivation and have been proposed as a target for non-invasive brain stimulation for the treatment of depression and anhedonia. Indeed, transcranial alternating current stimulation (tACS) at the alpha frequency reduced left frontal alpha power and was associated with a higher response rate than placebo stimulation in patients with major depressive disorder (MDD) in a recent double-blind placebo controlled clinical trial.

Methods: In this current study, we aimed to replicate successful target engagement by delineating the effects of a single session of bifrontal tACS at the individualized alpha frequency (IAF-tACS) on alpha oscillations in patients with MDD. 84 participants were randomized to receive verum or sham IAF-tACS. Electrical brain activity was recorded during rest and while viewing emotionally-salient images before and after stimulation to investigate if the modulation of alpha oscillation by tACS exhibited specificity with regards to valence.

Results: In agreement with the previous study of tACS in MDD, we found that a single session of bifrontal IAF-tACS reduced left frontal alpha power during the resting state when compared to placebo. Furthermore, the reduction of left frontal alpha oscillation by tACS was specific for stimuli with positive valence. In contrast, these effects on left frontal alpha power were not found in healthy control participants.

Conclusion: Together these results support an important role of tACS in reducing left frontal alpha oscillations as a future treatment for MDD.
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http://dx.doi.org/10.1016/j.bpsc.2021.07.001DOI Listing
July 2021

Electrocardiogram as a Lyme Disease Screening Test.

J Pediatr 2021 Jul 12. Epub 2021 Jul 12.

Division of Emergency Medicine, Boston Children's Hospital Boston, MA.

Objective: To examine the association between electrocardiographic (ECG) evidence of carditis at the time of Lyme disease evaluation and a diagnosis of Lyme disease.

Study Design: We performed an eight-center prospective cohort study of children undergoing emergency department evaluation for Lyme disease limited to those who had an ECG obtained by their treating clinicians. The study cardiologist reviewed all ECGs flagged as abnormal by the study sites to assess for ECG evidence of carditis. We defined Lyme disease with the presence of an erythema migrans lesion or a positive two-tier Lyme disease serology. We used logistic regression to measure the association between Lyme disease and AV block or any ECG evidence of carditis.

Results: Of the 546 children who had an ECG obtained, 214 (39%) had Lyme disease. Overall, 42 children had ECG evidence of carditis of which 24 had atrioventricular (AV) block (20 first degree). Of the patients with ECG evidence of carditis, only 21 (50%) had any cardiac symptoms. The presence of AV block (odds ratio 4.7, 95% confidence interval 1.8-12.1) and any ECG evidence of carditis (odds ratio 2.3, 95% confidence interval 1.2-4.3) were both associated with diagnosis of Lyme disease.

Conclusions: ECG evidence of carditis, especially AV block, was associated with a diagnosis of Lyme disease. ECG evidence of carditis can be used as a diagnostic biomarker for Lyme disease to guide initial management while awaiting Lyme disease test results.
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http://dx.doi.org/10.1016/j.jpeds.2021.07.010DOI Listing
July 2021

Impact of HIV status on systemic inflammation during pregnancy.

AIDS 2021 Jul 8. Epub 2021 Jul 8.

Department of Epidemiology, Columbia University Mailman School of Public Health, New York, USA Department of Medicine, Weill Cornell Medical College, New York, USA Department of Biostatistics, Columbia University Mailman School of Public Health, New York, USA Department of Obstetrics and Gynecology, Byramjee Jeejeebhoy Government Medical College, Pune, India Byramjee-Jeejeebhoy Government Medical college-Johns Hopkins University Clinical Research Site, Pune, India Instituto Goncalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil Multinational Organization Network Sponsoring Translational and Epidemiological Research, (MONSTER) Initiative, Salvador, Brazil Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil Curso de Medicina, Faculdade de Tecnologia e Ciências, Salvador, Brazil Universidade Salvador (UNIFACS), Laureate Universities, Salvador, Brazil Escola Bahiana de Medicina e Saúde Pública (EBMSP), Salvador, Brazil National Institutes of Health, National Institute for Research in Tuberculosis, International Center for Excellence in Research, Chennai, India Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, USA.

Objective: There are limited studies on the association of HIV infection with systemic inflammation during pregnancy.

Design: A cohort study (N = 220) of pregnant women with HIV (N = 70) (all on antiretroviral therapy) and without HIV (N = 150) were enrolled from an antenatal clinic in Pune, India.

Methods: The following systemic inflammatory markers were measured in plasma samples using immunoassays: soluble CD163 (sCD163), soluble CD14 (sCD14), intestinal fatty acid-binding protein (I-FABP), C-reactive protein (CRP), alpha 1-acid glycoprotein (AGP), interferon-β (IFNβ), interferon-γ (IFNγ), interleukin (IL)-1β, IL-6, IL-13, IL-17A and tumor necrosis factor α (TNFα). Generalized estimating equation (GEE) and linear regression models were used to assess the association of HIV status with each inflammatory marker during pregnancy and by trimester, respectively.

Results: Pregnant women with HIV had higher levels of markers for gut barrier dysfunction (I-FABP), monocyte activation (sCD14) and markers of systemic inflammation (IL-6 and TNFα), but surprisingly lower levels of AGP, an acute phase protein, compared to pregnant women without HIV, with some trimester-specific differences.

Conclusions: Our data show that women with HIV had higher levels of markers of gut barrier dysfunction, monocyte activation and systemic inflammation. These markers, some of which are associated with preterm birth, might help explain the increase in adverse birth outcomes in women with HIV and could suggest targets for potential interventions.
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http://dx.doi.org/10.1097/QAD.0000000000003016DOI Listing
July 2021

Turning the Corner.

Authors:
Mary Alexander

J Infus Nurs 2021 Jul-Aug 01;44(4):187

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http://dx.doi.org/10.1097/NAN.0000000000000435DOI Listing
July 2021