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Selected Works

Robert Paul

Articles 1 - 11 of 11

Full-Text Articles in Psychology

Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Nave Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda Oct 2018

Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Nave Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda

Robert Paul

Objectives Cognitive impairment remains frequent in HIV, despite combination antiretroviral therapy (cART). Leading theories implicate peripheral monocyte HIV DNA reservoirs as a mechanism for spread of the virus to the brain. These reservoirs remain present despite cART. The objective of this study was to determine if the level of HIV DNA in CD14+ enriched monocytes predicted cognitive impairment and brain injury. Methods We enrolled 61 cART-naïve HIV-infected Thais in a prospective study and measured HIV DNA in CD14+ enriched monocyte samples in a blinded fashion. We determined HAND diagnoses by consensus panel and all participants underwent magnetic resonance spectroscopy (MRS) …

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Understanding Reported Cognitive Dysfunction In Older Adults With Cardiovascular Disease, Robert H. Paul, John Gunstad, Ronald A. Cohen, David F. Oct 2018

Understanding Reported Cognitive Dysfunction In Older Adults With Cardiovascular Disease, Robert H. Paul, John Gunstad, Ronald A. Cohen, David F.

Robert Paul

High HIV-1 DNA (HIV DNA) levels in peripheral blood mononuclear cells (PBMC) correlate with HIV-1-associated dementia (HAD) in patients on highly active antiretroviral therapy (HAART). If this relationship also exists among HAART-naïve patients, then HIV DNA may be implicated in the pathogenesis of HAD. In this study, we evaluated the relationship between HIV DNA and cognition in subjects naïve to HAART in a neuro AIDS cohort in Bangkok, Thailand. Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. PBMC and cellular subsets were analyzed for HIV DNA using real-time PCR. The median …

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Application Of A Novel Quantitative Tractography Based Analysis Of Diffusion Tensor Imaging To Examine Fiber Bundle Length In Human Cerebral White Matter, Robert H. Paul, Laurie M. Baker, Ryan P. Cabeen, Sarah Cooley Oct 2018

Application Of A Novel Quantitative Tractography Based Analysis Of Diffusion Tensor Imaging To Examine Fiber Bundle Length In Human Cerebral White Matter, Robert H. Paul, Laurie M. Baker, Ryan P. Cabeen, Sarah Cooley

Robert Paul

This paper reviews basic methods and recent applications of length-based fiber bundle analysis of cerebral white matter using diffusion magnetic resonance imaging (dMRI). Diffusion weighted imaging (DWI) is a dMRI technique that uses the random motion of water to probe tissue microstructure in the brain. Diffusion tensor imaging (DTI) is an extension of DWI that measures the magnitude and direction of water diffusion in cerebral white matter, using either voxel-based scalar metrics or tractography-based analyses. More recently, quantitative tractography based on diffusion tensor imaging (qtDTI) technology has been developed to help quantify aggregate structural anatomical properties of white matter fiber …

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The Relationship Between Early Life Stress And Microstructural Integrity Of The Corpus Callosum In A Non-Clinical Population, Robert H. Paul, Lorrie Henry, Stuart M. Grieve, Thomas J. Guilmette Oct 2018

The Relationship Between Early Life Stress And Microstructural Integrity Of The Corpus Callosum In A Non-Clinical Population, Robert H. Paul, Lorrie Henry, Stuart M. Grieve, Thomas J. Guilmette

Robert Paul

Background: Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Methods: In the present study we evaluated this relationship in healthy non-clinical participants using diffusion tensor imaging (DTI) and self-reported history of ELS. …

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Structural And Functional Brain Imaging In Acute Hiv, Vishal Samboju, Carissa L. Philippi, Phillip Chan, Yann Cobigo, James L.K. Fletcher, Merlin Robb, Merlin Robb, Joanna Hellmuth, Khunthalee Benjapornpong, Netsiri Dumrongpisutikul, Mantana Pothisri, Robert Paul, Jintanat Ananworanich, Serena Spudich, Victor Valcour, Rv Protocol Teams Dec 2017

Structural And Functional Brain Imaging In Acute Hiv, Vishal Samboju, Carissa L. Philippi, Phillip Chan, Yann Cobigo, James L.K. Fletcher, Merlin Robb, Merlin Robb, Joanna Hellmuth, Khunthalee Benjapornpong, Netsiri Dumrongpisutikul, Mantana Pothisri, Robert Paul, Jintanat Ananworanich, Serena Spudich, Victor Valcour, Rv Protocol Teams

Robert Paul

Background:HIV RNA is identified in cerebrospinalfluid (CSF) within eightdays of estimated viral exposure. Neurological findings and impaired neuropsychological testing performance are documented in a subset of individuals with acuteHIV infection (AHI). The purpose of this study was to determine whether microstructural white matter and resting-state functional connectivity (rsFC) are disruptedin AHI.
Methods:We examined 49 AHI (100% male; mean age = 30 ± SD 9.9) and 23 HIV-uninfected Thai participants (78% male; age = 30 ± 5.5) with diffusion tensor imaging (DTI) and rsFC acquired at 3 Tesla, and four neuropsychological tests (summarized as NPZ-4). MRI for the AHI group was …

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Early Exposure To Traumatic Stressors Impairs Emotional Brain Circuitry, Robert H. Paul, Mayuresh S. Korgaonkar, Cassandra Antees, Leanne M. Williams, Justine M. Gatt, Richard A. Bryant, Ronald Cohen, Ruth O’Hara, Stuart M. Grieve Sep 2013

Early Exposure To Traumatic Stressors Impairs Emotional Brain Circuitry, Robert H. Paul, Mayuresh S. Korgaonkar, Cassandra Antees, Leanne M. Williams, Justine M. Gatt, Richard A. Bryant, Ronald Cohen, Ruth O’Hara, Stuart M. Grieve

Robert Paul

Exposure to early life trauma (ELT) is known to have a profound impact on mental development, leading to a higher risk for depression and anxiety. Our aim was to use multiple structural imaging methods to systematically investigate how traumatic stressors early in life impact the emotional brain circuits, typically found impaired with clinical diagnosis of depression and anxiety, across the lifespan in an otherwise healthy cohort. MRI data and self-reported histories of ELT from 352 healthy individuals screened for no psychiatric disorders were analyzed in this study. The volume and cortical thickness of the limbic and cingulate regions were assessed …

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Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Naïve Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda, Napapon Sailasuta, Thep Chalermchai, Alexandra Schuetz, Cecilia Shikuma, Chin-Yuan Liang, Supunee Jirajariyavej, Pasiri Sithinamsuwan, Somporn Tipsuk, David B. Clifford, James L.K. Fletcher, Mary A. Marovich, Bonnie M. Slike, Victor Degruttola, Bruce Shiramizu Jul 2013

Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Naïve Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda, Napapon Sailasuta, Thep Chalermchai, Alexandra Schuetz, Cecilia Shikuma, Chin-Yuan Liang, Supunee Jirajariyavej, Pasiri Sithinamsuwan, Somporn Tipsuk, David B. Clifford, James L.K. Fletcher, Mary A. Marovich, Bonnie M. Slike, Victor Degruttola, Bruce Shiramizu

Robert Paul

Objectives: Cognitive impairment remains frequent in HIV, despite combination antiretroviral therapy (cART). Leading theories implicate peripheral monocyte HIV DNA reservoirs as a mechanism for spread of the virus to the brain. These reservoirs remain present despite cART. The objective of this study was to determine if the level of HIV DNA in CD14+ enriched monocytes predicted cognitive impairment and brain injury.

Methods: We enrolled 61 cART-naı¨ve HIV-infected Thais in a prospective study and measured HIV DNA in CD14+ enriched monocyte samples in a blinded fashion. We determined HAND diagnoses by consensus panel and all participants underwent magnetic resonance spectroscopy (MRS) …

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Neuropsychological Outcomes In Adults Commencing Highly Active Anti-Retroviral Treatment In South Africa: A Prospective Study, John A. Joska, John A. Joska, Jennifer Westgarth-Taylor, Jacqueline Hoare, Kevin Gf Thomas, Robert Paul, Landon Myer, Dan J. Stein Nov 2012

Neuropsychological Outcomes In Adults Commencing Highly Active Anti-Retroviral Treatment In South Africa: A Prospective Study, John A. Joska, John A. Joska, Jennifer Westgarth-Taylor, Jacqueline Hoare, Kevin Gf Thomas, Robert Paul, Landon Myer, Dan J. Stein

Robert Paul

Background
Infection with HIV may result in significant neuropsychological impairment, especially in late stage disease. To date, there have been no cohort studies of the impact of highly active anti-retroviral treatment (HAART) in South Africa where clade C HIV is predominant.
Methods
Participants in the current study were recruited from a larger study of HIV-associated neurocognitive disorders (HAND) and included a group of individuals commencing HAART (n = 82). Baseline and one-year neuropsychological function was assessed using a detailed battery, and summary global deficit scores (GDS) obtained. Associations with change in GDS were calculated.

Results
Participants had a median CD4 …

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Normative Scores For A Brief Neuropsychological Battery For The Detection Of Hiv-Associated Neurocognitive Disorder (Hand) Among South Africans, Robert H. Paul Jan 2010

Normative Scores For A Brief Neuropsychological Battery For The Detection Of Hiv-Associated Neurocognitive Disorder (Hand) Among South Africans, Robert H. Paul

Robert Paul

Background
There is an urgent need to more accurately diagnose HIV-associated neurocognitive disorder (HAND) in Africa. Rapid screening tests for HIV-associated dementia are of limited utility due to variable sensitivity and specificity. The use of selected neuropsychological tests is more appropriate, but norms for HIV seronegative people are not readily available for sub-Saharan African populations. We sought to derive normative scores for two commonly used neuropsychological tests that generate four test scores -- namely the Trail-Making Test (Parts A and B) and the Digit Span Test [Forward (DSF) and Backward (DSB)]. To assess memory and recall, we used the memory …

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Relative Sensitivity Of Magnetic Resonance Spectroscopy And Quantitative Magnetic Resonance Imaging To Cognitive Function Among Nondemented Individuals Infected With Hiv, Robert H. Paul, Thomas M. Ernst, Adam M. Brickman, Constantin T. Yiannoutsos, David F. Tate, Ronald A. Cohen, Bradford A. Navia Aug 2008

Relative Sensitivity Of Magnetic Resonance Spectroscopy And Quantitative Magnetic Resonance Imaging To Cognitive Function Among Nondemented Individuals Infected With Hiv, Robert H. Paul, Thomas M. Ernst, Adam M. Brickman, Constantin T. Yiannoutsos, David F. Tate, Ronald A. Cohen, Bradford A. Navia

Robert Paul

In the present study, we examined the relationships among cognitive function, magnetic resonance spectroscopy (MRS) brain metabolite indices measured in the basal ganglia, and quantitative magnetic resonance imaging (MRI) of the caudate nucleus and the putamen in the earliest stages of HIV-related cognitive involvement. Participants included 22 HIV-positive individuals and 20 HIV-negative individuals. HIV-positive individuals performed significantly more poorly than the HIV-negative individuals on several cognitive measures. In addition, the choline/creatine ratio was significantly higher and the N-acetyl aspartate/choline ratio was significantly lower among HIV patients. The caudate and putamen sizes were smaller among HIV-positive patients compared with controls; however, …

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Hiv Dna And Dementia In Treatment-Naïve Hiv-1-Infected Individuals In Bangkok, Thailand, Robert H. Paul, Bruce Shiramizu, Silvia Ratto-Kim, Pasiri Sithinamsuwan, Samart Nidhinandana, Sataporn Thitivichianlert, George Watt, Mark Desouza, Thippawan Chuenchitra, Suchitra Sukwit, Suwicha Chitpatima, Kevin Robertson, Cecilia M. Shikuma, Victor Valcour Dec 2006

Hiv Dna And Dementia In Treatment-Naïve Hiv-1-Infected Individuals In Bangkok, Thailand, Robert H. Paul, Bruce Shiramizu, Silvia Ratto-Kim, Pasiri Sithinamsuwan, Samart Nidhinandana, Sataporn Thitivichianlert, George Watt, Mark Desouza, Thippawan Chuenchitra, Suchitra Sukwit, Suwicha Chitpatima, Kevin Robertson, Cecilia M. Shikuma, Victor Valcour

Robert Paul

High HIV-1 DNA (HIV DNA) levels in peripheral blood mononuclear cells (PBMC) correlate with HIV-1-associated dementia (HAD) in patients on highly active antiretroviral therapy (HAART). If this relationship also exists among HAART-naïve patients, then HIV DNA may be implicated in the pathogenesis of HAD. In this study, we evaluated the relationship between HIV DNA and cognition in subjects naïve to HAART in a neuro AIDS cohort in Bangkok, Thailand. Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. PBMC and cellular subsets were analyzed for HIV DNA using real-time PCR. The median …

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