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White CJ, Gausepohl AM, Wilkins HN, Eberhard CD, Orsburn BC, Williams DW. Spatial Heterogeneity of Brain Lipids in SIV-Infected Macaques Treated with Antiretroviral Therapy. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:185-196. [PMID: 38288997 DOI: 10.1021/jasms.3c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Human immunodeficiency virus (HIV) infection continues to promote neurocognitive impairment, mood disorders, and brain atrophy, even in the modern era of viral suppression. Brain lipids are vulnerable to HIV-associated energetic strain and may contribute to HIV-associated neurologic dysfunction due to alterations in lipid breakdown and structural lipid composition. HIV neuropathology is region dependent, yet there has not been comprehensive characterization of the spatial heterogeneity of brain lipids during infection that possibly impacts neurologic function. To address this gap, we evaluated the spatial lipid distribution using matrix laser desorption/ionization imaging mass spectrometry (MALDI-IMS) across four brain regions (parietal cortex, midbrain, thalamus, and temporal cortex), as well as the kidney for a peripheral tissue control, in a simian immunodeficiency virus (SIV)-infected rhesus macaque treated with a course of antiretroviral therapies (ARTs). We assessed lipids indicative of fat breakdown [acylcarnitines (CARs)] and critical structural lipids [phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs)] across fatty acid chain lengths and degrees of unsaturation. CARs with very long-chain, polyunsaturated fatty acids (PUFAs) were more abundant across all brain regions than shorter chain, saturated, or monounsaturated species. We observed distinct brain lipid distribution patterns for the CARs and PCs. However, no clear expression patterns emerged for PEs. Surprisingly, the kidney was nearly devoid of ions corresponding to PUFAs common in brain. PEs and PCs with PUFAs had little intensity and less density than other species, and only one CAR species was observed in kidney at high intensity. Overall, our study demonstrates the stark variation in structural phospholipids and lipid-energetic intermediates present in the virally suppressed SIV-macaque brain. These findings may be useful for identifying regional vulnerabilities to damage due to brain lipid changes in people with HIV.
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Affiliation(s)
- Cory J White
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Andrew M Gausepohl
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Hannah N Wilkins
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Colten D Eberhard
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Benjamin C Orsburn
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Dionna W Williams
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Medicine, Division of Clinical Pharmacology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Molecular Microbiology & Immunology, Johns Hopkins University School of Public Health, Baltimore, Maryland 21205, United States
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
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Liu J, Nguchu BA, Liu D, Qi Y, Aili X, Han S, Gao Y, Wang X, Qiao H, Cai C, Huang X, Li H. Longitudinal white matter alterations in SIVmac239-infected rhesus monkeys with and without regular cART treatment. Front Immunol 2023; 13:1067795. [PMID: 36713432 PMCID: PMC9879061 DOI: 10.3389/fimmu.2022.1067795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/19/2022] [Indexed: 01/15/2023] Open
Abstract
Objective To use SIV-mac239-infected Chinese rhesus monkeys to study white matter changes with and without regular combined antiretroviral therapy (cART) and the relationships between the changes and clinical results. Methods Diffusion tensor imaging (DTI) data were collected at baseline and 10 days, 4 weeks, 12 weeks, 24 weeks, and 36 weeks after viral inoculation. Plasma CD4 T cell counts, CD4/CD8 ratio, plasma viral load, and cerebrospinal fluid (CSF) viral load were collected at baseline and 1 week, 5 weeks, 12 weeks, 24 weeks, and 36 weeks after viral inoculation. Microstructural characteristics were examined within 76 white matter areas defined by the DTI-white matter (WM) atlas for rhesus macaques. Corrections for multiple comparisons were performed using a false discovery rate (p < 0.05, FDR). Correlation analyzes between imaging markers and clinical markers (plasma CD4 T cell counts, CD4/CD8 ratio, plasma viral load, and cerebral spinal fluid viral load) were performed using Pearson correlations. Results White matter changes in SIV-infected macaques were detected in different brain regions as early as 4 weeks after inoculation. As time progressed, cART reversed, ameliorated, or even enhanced the effects. The CD4 T cell count was mainly associated with DTI metrics before cART, while the CD4/CD8 ratio was associated with white matter changes with and without cART. Viral load was positively associated with mean diffusivity in HIV patients without cART, and the opposite results were seen in HIV patients with cART. Conclusion SIV-mac239 infection may be an ideal tool for studying HIV-induced changes in the brain. The first white matter changes appeared in a structure adjacent to the periventricular area as early as 4 weeks after inoculation. As time progressed, cART had different effects on different regions, reversing, attenuating, or even progressing the pathology. Moreover, these changes were closely related to the CD4/CD8 ratio and viral load, even after cART.
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Affiliation(s)
- Jiaojiao Liu
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | | | - Dan Liu
- Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu Qi
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Xire Aili
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
| | - Shuai Han
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Yuxun Gao
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Xiaoxiao Wang
- Center for Biomedical Imaging, University of Science and Technology of China, Hefei, China
| | - Hongwei Qiao
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences, Beijing, China
| | - Chao Cai
- Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Xiaojie Huang
- Clinical and Research Center for Infectious Diseases, Beijing YouAn Hospital, Capital Medical University, Beijing, China,*Correspondence: Xiaojie Huang, ; Hongjun Li,
| | - Hongjun Li
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China,Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China,*Correspondence: Xiaojie Huang, ; Hongjun Li,
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Ma J, Yang X, Xu F, Li H. Application of Diffusion Tensor Imaging (DTI) in the Diagnosis of HIV-Associated Neurocognitive Disorder (HAND): A Meta-Analysis and a System Review. Front Neurol 2022; 13:898191. [PMID: 35873786 PMCID: PMC9302369 DOI: 10.3389/fneur.2022.898191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/20/2022] [Indexed: 12/20/2022] Open
Abstract
Background The patients with HIV-associated neurocognitive disorder (HAND) are often accompanied by white matter structure damage. Diffusion tensor imaging (DTI) is an important tool to detect white matter structural damage. However, the changes in DTI values reported in many studies are diverse in different white matter fiber tracts and brain regions. Purpose Our research is dedicated to evaluating the consistency and difference of the correlation between HAND and DTI measures in different studies. Additionally, the value of DTI in HAND evaluation is used to obtain consensus and independent conclusions between studies. Methods We searched PubMed and Web of Science to collect relevant studies using DTI for the diagnosis of HAND. After screening and evaluating the search results, meta-analysis is used for quantitative research on data. Articles that cannot collect data but meet the research relevance will be subjected to a system review. Results The meta-analysis shows that the HAND group has lower fractional anisotropy (standardized mean difference = −0.57 p < 0.0001) and higher mean diffusivity (standardized mean difference = 0.04 p < 0.0001) than the healthy control group in corpus callosum. In other white matter fibers, we found similar changes in fractional anisotropy (standardized mean difference = −1.18 p < 0.0001) and mean diffusivity (standardized mean difference = 0.69 p < 0.0001). However, the heterogeneity (represented by I2) between the studies is high (in corpus callosum 94, 88%, in other matter fibers 95, 81%). After subgroup analysis, the heterogeneity is obtained as 19.5, 40.7% (FA, MD in corpus callosum) and 0, 0% (FA, MD among other white matter fibers). Conclusion The changes in white matter fibers in patients with HAND are statistically significant at the observation level of DTI compared with healthy people. The differences between the studies are mainly derived from demographics, start and maintenance time of antiretroviral therapy, differences in nadir CD4+T cells, and the use of different neurocognitive function scales. As an effective method to detect the changes in white matter fibers, DTI is of great significance for the diagnosis of HAND, but there are still some shortcomings. In the absence of neurocognitive function scales, independent diagnosis remains difficult. Systematic Review Registration:https://inplasy.com/inplasy-2021-10-0079/.
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Affiliation(s)
- Juming Ma
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Xue Yang
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Fan Xu
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
| | - Hongjun Li
- Department of Radiology, Beijing YouAn Hospital, Capital Medical University, Beijing, China
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
- *Correspondence: Hongjun Li
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Barkaway A, Attwell D, Korte N. Immune-vascular mural cell interactions: consequences for immune cell trafficking, cerebral blood flow, and the blood-brain barrier. NEUROPHOTONICS 2022; 9:031914. [PMID: 35581998 PMCID: PMC9107322 DOI: 10.1117/1.nph.9.3.031914] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
Brain barriers are crucial sites for cerebral energy supply, waste removal, immune cell migration, and solute exchange, all of which maintain an appropriate environment for neuronal activity. At the capillary level, where the largest area of brain-vascular interface occurs, pericytes adjust cerebral blood flow (CBF) by regulating capillary diameter and maintain the blood-brain barrier (BBB) by suppressing endothelial cell (EC) transcytosis and inducing tight junction expression between ECs. Pericytes also limit the infiltration of circulating leukocytes into the brain where resident microglia confine brain injury and provide the first line of defence against invading pathogens. Brain "waste" is cleared across the BBB into the blood, phagocytosed by microglia and astrocytes, or removed by the flow of cerebrospinal fluid (CSF) through perivascular routes-a process driven by respiratory motion and the pulsation of the heart, arteriolar smooth muscle, and possibly pericytes. "Dirty" CSF exits the brain and is probably drained around olfactory nerve rootlets and via the dural meningeal lymphatic vessels and possibly the skull bone marrow. The brain is widely regarded as an immune-privileged organ because it is accessible to few antigen-primed leukocytes. Leukocytes enter the brain via the meninges, the BBB, and the blood-CSF barrier. Advances in genetic and imaging tools have revealed that neurological diseases significantly alter immune-brain barrier interactions in at least three ways: (1) the brain's immune-privileged status is compromised when pericytes are lost or lymphatic vessels are dysregulated; (2) immune cells release vasoactive molecules to regulate CBF, modulate arteriole stiffness, and can plug and eliminate capillaries which impairs CBF and possibly waste clearance; and (3) immune-vascular interactions can make the BBB leaky via multiple mechanisms, thus aggravating the influx of undesirable substances and cells. Here, we review developments in these three areas and briefly discuss potential therapeutic avenues for restoring brain barrier functions.
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Affiliation(s)
- Anna Barkaway
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - David Attwell
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Nils Korte
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
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Moretti S, Virtuoso S, Sernicola L, Farcomeni S, Maggiorella MT, Borsetti A. Advances in SIV/SHIV Non-Human Primate Models of NeuroAIDS. Pathogens 2021; 10:pathogens10081018. [PMID: 34451482 PMCID: PMC8398602 DOI: 10.3390/pathogens10081018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 08/04/2021] [Accepted: 08/11/2021] [Indexed: 01/09/2023] Open
Abstract
Non-human primates (NHPs) are the most relevant model of Acquired Immunodeficiency Syndrome (AIDS) and neuroAIDS, being of great importance in explaining the pathogenesis of HIV-induced nervous system damage. Simian Immunodeficiency Virus (SIV)/ Simian-Human Immunodeficiency Virus (SHIV)-infected monkeys have provided evidence of complex interactions between the virus and host that include host immune response, viral genetic diversity, and genetic susceptibility, which may explain virus-associated central nervous system (CNS) pathology and HIV-associated neurocognitive disorders (HAND). In this article, we review the recent progress contributions obtained using monkey models of HIV infection of the CNS, neuropathogenesis and SIV encephalitis (SIVE), with an emphasis on pharmacologic therapies and dependable markers that predict development of CNS AIDS.
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Zhang X, Li CX, Yan Y, Nair G, Rilling JK, Herndon JG, Preuss TM, Hu X, Li L. In-vivo diffusion MRI protocol optimization for the chimpanzee brain and examination of aging effects on the primate optic nerve at 3T. Magn Reson Imaging 2020; 77:194-203. [PMID: 33359631 DOI: 10.1016/j.mri.2020.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/30/2020] [Accepted: 12/20/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Diffusion MRI (dMRI) data acquisition protocols are well-established on modern high-field clinical scanners for human studies. However, these protocols are not suitable for the chimpanzee (or other large-brained mammals) because of its substantial difference in head geometry and brain volume compared with humans. Therefore, an optimal dMRI data acquisition protocol dedicated to chimpanzee neuroimaging is needed. METHODS A multi-shot (4 segments) double spin-echo echo-planar imaging (MS-EPI) sequence and a single-shot double spin-echo EPI (SS-EPI) sequence were optimized separately for in vivo dMRI data acquisition of chimpanzees using a clinical 3T scanner. Correction for severe susceptibility-induced image distortion and signal drop-off of the chimpanzee brain was performed and evaluated using FSL software. DTI indices in different brain regions and probabilistic tractography were compared. A separate DTI data set from n=34 chimpanzees (13 to 56 years old) was collected using the optimal protocol. Age-related changes in diffusivity indices of optic nerve fibers were evaluated. RESULTS The SS-EPI sequence acquired dMRI data of the chimpanzee brain with approximately doubled the SNR as the MS-EPI sequence given the same scan time. The quality of white matter fiber tracking from the SS-EPI data was much higher than that from MS-EPI data. However, quantitative analysis of DTI indices showed no difference in most ROIs between the SS-EPI and MS-EPI sequences. The progressive evolution of diffusivity indices of optic nerves indicated mild changes in fiber bundles of chimpanzees aged 40 years and above. CONCLUSION The single-shot EPI-based acquisition protocol provided better image quality of dMRI for chimpanzee brains and is recommended for in vivo dMRI study or clinical diagnosis of chimpanzees (or other large animals) using a clinical scanner. Also, the tendency of FA decrease or diffusivity increase in the optic nerve of aged chimpanzees was seen but did not show significant age-related changes, suggesting aging may have less impact on optic nerve fiber integrity of chimpanzees, in contrast to previous results for both macaque monkeys and humans.
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Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America.
| | - Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Yumei Yan
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Govind Nair
- qMRI Core Facility, NINDS, NIH, Bethesda, MD 20892, United States of America
| | - James K Rilling
- Department of Anthropology, Emory University, Atlanta, GA, United States of America; Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - James G Herndon
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Todd M Preuss
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States of America
| | - Xiaoping Hu
- Dept of Bioengineering, University of California, Riverside, CA, United States of America
| | - Longchuan Li
- Marcus Autism Center, Children's Healthcare of Atlanta, Emory University, Atlanta, GA, United States of America.
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Regional Brain Recovery from Acute Synaptic Injury in Simian Immunodeficiency Virus-Infected Rhesus Macaques Associates with Heme Oxygenase Isoform Expression. J Virol 2020; 94:JVI.01102-20. [PMID: 32669339 PMCID: PMC7495379 DOI: 10.1128/jvi.01102-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/10/2020] [Indexed: 12/21/2022] Open
Abstract
Brain injury induced by acute simian (or human) immunodeficiency virus infection may persist or spontaneously resolve in different brain regions. Identifying the host factor(s) that promotes spontaneous recovery from such injury may reveal targets for therapeutic drug strategies for promoting recovery from acute neuronal injury. The gradual recovery from such injury observed in many, but not all, brain regions in the rhesus macaque model is consistent with the possible existence of a therapeutic window of opportunity for intervening to promote recovery, even in those regions not showing spontaneous recovery. In persons living with human immunodeficiency virus infection, such neuroprotective treatments could ultimately be considered as adjuncts to the initiation of antiretroviral drug therapy. Brain injury occurs within days in simian immunodeficiency virus (SIV) or human immunodeficiency virus (HIV) infection, and some recovery may occur within weeks. Inflammation and oxidative stress associate with such injury, but what drives recovery is unknown. Chronic HIV infection associates with reduced brain frontal cortex expression of the antioxidant/anti-inflammatory enzyme heme oxygenase-1 (HO-1) and increased neuroinflammation in individuals with cognitive impairment. We hypothesized that acute regional brain injury and recovery associate with differences in regional brain HO-1 expression. Using SIV-infected rhesus macaques, we analyzed multiple brain regions through acute and chronic infection (90 days postinfection [dpi]) and quantified viral (SIV gag RNA), synaptic (PSD-95; synaptophysin), axonal (neurofilament/neurofilament light chain [NFL]), inflammatory, and antioxidant (enzymes, including heme oxygenase isoforms [HO-1, HO-2]) markers. PSD-95 was reduced in the brainstem, basal ganglia, neocortex, and cerebellum within 13 dpi, indicating acute synaptic injury throughout the brain. All areas except the brainstem recovered. Unchanged NFL was consistent with no acute axonal injury. SIV RNA expression was highest in the brainstem throughout infection, and it associated with neuroinflammation. Surprisingly, during the synaptic injury and recovery phases, HO-2, and not HO-1, progressively decreased in the brainstem. Thus, acute SIV synaptic injury occurs throughout the brain, with spontaneous recovery in regions other than the brainstem. Within the brainstem, the high SIV load and inflammation, along with reduction of HO-2, may impair recovery. In other brain regions, stable HO-2 expression, with or without increasing HO-1, may promote recovery. Our data support roles for heme oxygenase isoforms in modulating recovery from synaptic injury in SIV infection and suggest their therapeutic targeting for promoting neuronal recovery. IMPORTANCE Brain injury induced by acute simian (or human) immunodeficiency virus infection may persist or spontaneously resolve in different brain regions. Identifying the host factor(s) that promotes spontaneous recovery from such injury may reveal targets for therapeutic drug strategies for promoting recovery from acute neuronal injury. The gradual recovery from such injury observed in many, but not all, brain regions in the rhesus macaque model is consistent with the possible existence of a therapeutic window of opportunity for intervening to promote recovery, even in those regions not showing spontaneous recovery. In persons living with human immunodeficiency virus infection, such neuroprotective treatments could ultimately be considered as adjuncts to the initiation of antiretroviral drug therapy.
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8
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Li CX, Patel S, Zhang X. Evaluation of multi-shell diffusion MRI acquisition strategy on quantitative analysis using multi-compartment models. Quant Imaging Med Surg 2020; 10:824-834. [PMID: 32355646 DOI: 10.21037/qims.2020.03.11] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Background Multi-compartment diffusion models such as Neurite Orientation Dispersion and Density Imaging (NODDI) have been increasingly used for diffusion MRI (dMRI) data processing in biomedical research. However, those models usually require multiple HARDI shells that may increase scanning duration substantially, and their application can be hindered in uncooperative patients (like infants) accordingly. Also, it is highly expected that the same dataset can be explored with multiple diffusion models for retrieving complementary information. Methods Multiple gradient-encoding schemes which consisted of 4-6 shells, moderate b-values (bmax =1,500 or 2,000 s/mm2), and 32-80 gradient directions were explored. The corresponding time of acquisition (TA) for a single scan ranged from 3 to 8 minutes respectively. The dMRI protocols were tested on macaque monkeys using a 3T clinical setting. The data were analysed using both NODDI and diffusion basic spectrum imaging (DBSI) models. Results The maps of orientation dispersion index (ODI) and CSF were consistent across the 4-6 shell sampling schemes. However, the corresponding intra-cellular volume fraction (ICVF) maps showed reduced pixel counts [1,100±98 (80 directions) vs. 806±70 (32 directions), one slice] in white matter when fewer gradient directions or lower b-value was applied. The hindered diffusion and CSF ratio maps were comparable across these sampling schemes. The maps of restricted diffusion ratio varied across the schemes. However, its mean ratios (0.23±0.02 vs. 0.22±0.01) and pixel counts (1,540±70 vs. 1,510±38, one slice) between the schemes of 80 and 32 directions with b=2,000 s/mm2 were comparable. Conclusions The present study reports a fast multi-shell dMRI data acquisition and processing strategy which allows for obtaining complementary information about microstructural alteration and inflammation from a single dMRI data set with both NODDI and DBSI models. The proposed approach may be particularly useful for characterizing the neurodegenerative disorders in uncooperative patients like children or acute stroke patients in which brain injury is associated with inflammation.
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Affiliation(s)
- Chun-Xia Li
- Yerkes Imaging Center, Emory University, Atlanta, GA, USA
| | - Sudeep Patel
- Yerkes Imaging Center, Emory University, Atlanta, GA, USA
| | - Xiaodong Zhang
- Yerkes Imaging Center, Emory University, Atlanta, GA, USA.,Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
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Zhao J, Chen F, Ren M, Li L, Li A, Jing B, Li H. Low-frequency fluctuation characteristics in rhesus macaques with SIV infection: a resting-state fMRI study. J Neurovirol 2018; 25:141-149. [PMID: 30478797 DOI: 10.1007/s13365-018-0694-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/16/2018] [Accepted: 10/25/2018] [Indexed: 12/18/2022]
Abstract
Simian immunodeficiency virus (SIV)-infected macaque is a widely used model to study human immunodeficiency virus. The purpose of the study is to discover the amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF) changes in SIV-infected macaques. Seven rhesus macaques were involved in the longitudinal MRI scans: (1) baseline (healthy state); (2) SIV infection stage (12 weeks after SIV inoculation). ALFF and fALFF were subsequently computed and compared to ascertain the changes caused by SIV infection. Whole-brain correlation analysis was further used to explore the possible associations between ALFF/fALFF values and immune status parameters (CD4+ T cell counts, CD4/CD8 ratio and virus load). Compared with the baseline, macaques in SIV infection stage displayed strengthened ALFF values in left precuneus, postcentral gyrus, and temporal gyrus, and weakened ALFF values in orbital gyrus and inferior temporal gyrus. Meanwhile, increased fALFF values were found in left superior frontal gyrus, right precentral gyrus, and superior temporal gyrus, while decreased fALFF values existed in left hippocampus, left caudate, and right inferior frontal gyrus. Furthermore, ALFF and fALFF values in several brain regions showed significant relationships with CD4+ T cell counts, CD4/CD8 ratio, and plasma virus load. Our findings could promote the understanding of neuroAIDS caused by HIV infection, which may provide supplementary evidences for the future therapy study in SIV model.
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Affiliation(s)
- Jing Zhao
- Department of Radiology, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An MenWai, Feng Tai District, Beijing, 100069, China
| | - Feng Chen
- Department of Radiology, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An MenWai, Feng Tai District, Beijing, 100069, China
| | - Meiji Ren
- Department of Radiology, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An MenWai, Feng Tai District, Beijing, 100069, China
| | - Li Li
- Department of Radiology, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An MenWai, Feng Tai District, Beijing, 100069, China
| | - Aixin Li
- Department of Infectious Diseases, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An Men Wai, Feng Tai District, Beijing, 10069, China
| | - Bin Jing
- School of Biomedical Engineering, Capital Medical University, No.10, Xi Tou Tiao, You An Men Wai, Feng Tai District, Beijing, 100069, China.
| | - Hongjun Li
- Department of Radiology, Beijing Youan Hospital, Capital Medical University, No.8, Xi Tou Tiao, You An MenWai, Feng Tai District, Beijing, 100069, China.
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Zhang S, Jiang X, Zhang W, Zhang T, Chen H, Zhao Y, Lv J, Guo L, Howell BR, Sanchez MM, Hu X, Liu T. Joint representation of connectome-scale structural and functional profiles for identification of consistent cortical landmarks in macaque brain. Brain Imaging Behav 2018; 13:1427-1443. [PMID: 30178424 DOI: 10.1007/s11682-018-9944-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Discovery and representation of common structural and functional cortical architectures has been a significant yet challenging problem for years. Due to the remarkable variability of structural and functional cortical architectures in human brain, it is challenging to jointly represent a common cortical architecture which can comprehensively encode both structure and function characteristics. In order to better understand this challenge and considering that macaque monkey brain has much less variability in structure and function compared with human brain, in this paper, we propose a novel computational framework to apply our DICCCOL (Dense Individualized and Common Connectivity-based Cortical Landmarks) and HAFNI (Holistic Atlases of Functional Networks and Interactions) frameworks on macaque brains, in order to jointly represent structural and functional connectome-scale profiles for identification of a set of consistent and common cortical landmarks across different macaque brains based on multimodal DTI and resting state fMRI (rsfMRI) data. Experimental results demonstrate that 100 consistent and common cortical landmarks are successfully identified via the proposed framework, each of which has reasonably accurate anatomical, structural fiber connection pattern, and functional correspondences across different macaque brains. This set of 100 landmarks offer novel insights into the structural and functional cortical architectures in macaque brains.
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Affiliation(s)
- Shu Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA
| | - Xi Jiang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA
| | - Wei Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA
| | - Tuo Zhang
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA.,School of Automation, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Hanbo Chen
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA
| | - Yu Zhao
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA
| | - Jinglei Lv
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA.,School of Automation, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Lei Guo
- School of Automation, Northwestern Polytechnical University, Xi'an, People's Republic of China
| | - Brittany R Howell
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA.,Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Institute of Child Development, University of Minnesota, Minneapolis, MN, USA
| | - Mar M Sanchez
- Department of Psychiatry & Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA. .,Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.
| | - Xiaoping Hu
- Department of Bioengineering, UC Riverside, Riverside, CA, USA.
| | - Tianming Liu
- Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Boyd GSRC 420, Athens, GA, 30602, USA.
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11
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Takemura H, Pestilli F, Weiner KS, Keliris GA, Landi SM, Sliwa J, Ye FQ, Barnett MA, Leopold DA, Freiwald WA, Logothetis NK, Wandell BA. Occipital White Matter Tracts in Human and Macaque. Cereb Cortex 2017; 27:3346-3359. [PMID: 28369290 PMCID: PMC5890896 DOI: 10.1093/cercor/bhx070] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 03/01/2017] [Accepted: 03/04/2017] [Indexed: 12/17/2022] Open
Abstract
We compare several major white-matter tracts in human and macaque occipital lobe using diffusion magnetic resonance imaging. The comparison suggests similarities but also significant differences in the tracts. There are several apparently homologous tracts in the 2 species, including the vertical occipital fasciculus (VOF), optic radiation, forceps major, and inferior longitudinal fasciculus (ILF). There is one large human tract, the inferior fronto-occipital fasciculus, with no corresponding fasciculus in macaque. We could identify the macaque VOF (mVOF), which has been little studied. Its position is consistent with classical invasive anatomical studies by Wernicke. VOF homology is supported by similarity of the endpoints in V3A and ventral V4 across species. The mVOF fibers intertwine with the dorsal segment of the ILF, but the human VOF appears to be lateral to the ILF. These similarities and differences between the occipital lobe tracts will be useful in establishing which circuitry in the macaque can serve as an accurate model for human visual cortex.
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Affiliation(s)
- Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita-shi, Osaka 565-0871, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita-shi, Osaka 565-0871, Japan
| | - Franco Pestilli
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Kevin S. Weiner
- Department of Psychology, Stanford University, Stanford, CA 94305, USA
| | - Georgios A. Keliris
- Max Planck Institute for Biological Cybernetics, 72072 Tübingen, Germany
- Bio-Imaging Laboratory, Department of Biomedical Sciences, University of Antwerp, Wilrijk 2610, Belgium
| | - Sofia M. Landi
- Laboratory of Neural Systems, The Rockefeller University, New York, NY 10065, USA
| | - Julia Sliwa
- Laboratory of Neural Systems, The Rockefeller University, New York, NY 10065, USA
| | - Frank Q. Ye
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Eye Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | | | - David A. Leopold
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, National Eye Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | - Winrich A. Freiwald
- Laboratory of Neural Systems, The Rockefeller University, New York, NY 10065, USA
| | | | - Brian A. Wandell
- Department of Psychology, Stanford University, Stanford, CA 94305, USA
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12
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Li CX, Zhang X. Whole body MRI of the non-human primate using a clinical 3T scanner: initial experiences. Quant Imaging Med Surg 2017; 7:267-275. [PMID: 28516052 PMCID: PMC5418147 DOI: 10.21037/qims.2017.04.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 04/07/2017] [Indexed: 12/12/2022]
Abstract
With the advent of parallel imaging MRI techniques, whole-body MRI is being increasingly used in clinical diagnosis. However, its application in preclinical research using large animals remains very limited. In the present study, the whole-body MRI techniques for adult macaque monkeys were explored using a conventional clinic 3T scanner. The T1, T2 anatomical images, and MR angiography of adult macaque whole bodies were illustrated. The preliminary results suggest whole-body MRI can be a robust tool to examine multiple organs of non-human primate (NHP) models from head to toe non-invasively and simultaneously using a conventional clinical setting. As NHPs are intensely used in biomedical research such as HIV/AIDS and vaccine discovery, whole body MRI techniques can have a wide range of applications in translational research using NHPs.
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Affiliation(s)
- Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
- Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
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13
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Ackermann C, Andronikou S, Saleh MG, Laughton B, Alhamud AA, van der Kouwe A, Kidd M, Cotton MF, Meintjes EM. Early Antiretroviral Therapy in HIV-Infected Children Is Associated with Diffuse White Matter Structural Abnormality and Corpus Callosum Sparing. AJNR Am J Neuroradiol 2016; 37:2363-2369. [PMID: 27538904 DOI: 10.3174/ajnr.a4921] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/04/2016] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND PURPOSE Fractional anisotropy in the frontal white matter, corpus callosum, and internal capsule is abnormal in human immunodeficiency virus-positive (HIV+) adults. We describe the distribution and nature of white matter abnormalities in a cohort of children who started antiretroviral therapy within the first year of life and the benefit of early treatment by using DTI measures (fractional anisotropy and mean, axial, and radial diffusion). MATERIALS AND METHODS DTI was performed on children in a neurodevelopmental substudy from the Children with HIV Early Antiretroviral trial. Voxel-based group comparisons were obtained to determine regions where fractional anisotropy and mean diffusion differed between HIV+ and uninfected children. Associations of DTI parameters with the timing of antiretroviral therapy initiation were examined. RESULTS Thirty-nine HIV+ children (15 boys; mean age, 5.4 years) and 13 controls (5 boys; mean age, 5.7 years) were scanned. Two clusters with lower fractional anisotropy and 7 clusters with increased mean diffusion were identified in the HIV+ group, with symmetric distribution predominantly due to increased radial diffusion, suggestive of decreased myelination. Corticospinal tracts rather than the corpus callosum were predominantly involved. Children on early-interrupted antiretroviral therapy had lower fractional anisotropy compared with those receiving continuous treatment. CONCLUSIONS HIV+ children at 5 years of age have white matter abnormalities measured by fractional anisotropy, despite early antiretroviral therapy, suggesting that early antiretroviral therapy does not fully protect the white matter from either peripartum or in utero infection. In contrast to adults, the corticospinal tracts are predominantly involved rather than the corpus callosum, possibly due to early antiretroviral therapy. Continuous early antiretroviral therapy can limit white matter damage.
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Affiliation(s)
- C Ackermann
- From the Departments of Radiodiagnosis (C.A.)
| | - S Andronikou
- Clinical Research and Imaging Centre, Bristol (S.A.), University of Bristol, Bristol, UK
- Department of Paediatric Radiology (S.A.), Bristol Royal Hospital for Children, Bristol, UK
| | - M G Saleh
- Department of Human Biology (M.G.S., A.A.A., E.M.M.), Medical Research Council/University of Cape Town Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | - B Laughton
- Paediatrics and Child Health (B.L., M.F.C.), Faculty of Medicine and Health Sciences
| | - A A Alhamud
- Department of Human Biology (M.G.S., A.A.A., E.M.M.), Medical Research Council/University of Cape Town Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | - A van der Kouwe
- Athinoula A. Martinos Center for Biomedical Imaging (A.v.d.K.), Massachusetts General Hospital, Charlestown, Massachusetts
| | - M Kidd
- Centre for Statistical Consultation (M.K.), Stellenbosch University, Tygerberg, South Africa
| | - M F Cotton
- Paediatrics and Child Health (B.L., M.F.C.), Faculty of Medicine and Health Sciences
| | - E M Meintjes
- Department of Human Biology (M.G.S., A.A.A., E.M.M.), Medical Research Council/University of Cape Town Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
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14
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Zhang X, Li CX. Arterial spin labeling perfusion magnetic resonance imaging of non-human primates. Quant Imaging Med Surg 2016; 6:573-581. [PMID: 27942478 DOI: 10.21037/qims.2016.10.05] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Non-human primates (NHPs) resemble most aspects of humans in brain physiology and anatomy and are excellent animal models for translational research in neuroscience, biomedical research and pharmaceutical development. Cerebral blood flow (CBF) offers essential physiological information of the brain to examine the abnormal functionality in NHP models with cerebral vascular diseases and neurological disorders or dementia. Arterial spin labeling (ASL) perfusion MRI techniques allow for high temporal and spatial CBF measurement and are intensively used in studies of animals and humans. In this article, current high-resolution ASL perfusion MRI techniques for quantitative evaluation of brain physiology and function in NHPs are described and their applications and limitation are discussed as well.
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Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA;; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA
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15
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Ann HW, Jun S, Shin NY, Han S, Ahn JY, Ahn MY, Jeon YD, Jung IY, Kim MH, Jeong WY, Ku NS, Kim JM, Smith DM, Choi JY. Characteristics of Resting-State Functional Connectivity in HIV-Associated Neurocognitive Disorder. PLoS One 2016; 11:e0153493. [PMID: 27104345 PMCID: PMC4841538 DOI: 10.1371/journal.pone.0153493] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 03/30/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND HIV-associated neurocognitive disorder (HAND) can occur in patients without prior AIDS defining illness and can be debilitating. This study aimed to evaluate the difference in the patterns of intrinsic brain activity between patients with or without HAND for deepening our understanding of HAND. METHODS We evaluated 24 HIV-infected individuals, 12 with previously diagnosed HAND and 12 previously diagnosed without HAND, and 11 seronegative individuals. These individuals then underwent repeat NP testing and a functional brain MRI scan. For functional MRI analysis, seed-based analysis with bilateral precuneus cortex seed was applied. RESULTS Among the 12 individuals with previously diagnosed HAND, 3 showed improvement of their neurocognitive function and 1 was excluded for worsening liver disease. Among the 12 patients who previously had normal neurocognitive function, 2 showed neurocognitive impairment. Overall, the HAND group, who had impaired cognitive function at the time of MRI scan, showed significant decrease of resting status functional connectivity between bilateral precuneus and prefrontal cortex (PFC) compared with nonHAND group, those who had normal neurocognitive function (Corrected P<0.05). The functional connectivity with the right inferior frontal operculum and right superior frontal gyrus was positively correlated with memory and learning ability. CONCLUSIONS This cross-sectional study found a significant difference in fMRI patterns between patients with and without HAND. Decreased functional connectivity between precuneus and PFC could be possible functional substrate for cognitive dysfunction in HIV patients, which should be characterized in a longitudinal study.
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Affiliation(s)
- Hea Won Ann
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Suhnyoung Jun
- Department of Psychology, Yonsei University, Seoul, South Korea
| | - Na-Young Shin
- Department of Radiology, Ewha Womans University School of Medicine, Seoul, South Korea
| | - Sanghoon Han
- Department of Psychology, Yonsei University, Seoul, South Korea
| | - Jin Young Ahn
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Mi Young Ahn
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Yong Duk Jeon
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - In Young Jung
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Moo Hyun Kim
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Woo Yong Jeong
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Nam Su Ku
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - June Myung Kim
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
| | - Davey M. Smith
- Department of Medicine, University of California San Diego, La Jolla, CA, United States of America
- Veterans Affairs San Diego Healthcare System, San Diego, CA, United States of America
| | - Jun Yong Choi
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
- Department of AIDS Research Institute, Yonsei University College of Medicine, Seoul, South Korea
- * E-mail:
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16
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Zhang X, Kirsch JE, Zhong X. Artifact correction in diffusion MRI of non-human primate brains on a clinical 3T scanner. J Med Primatol 2015; 45:21-7. [PMID: 26689605 DOI: 10.1111/jmp.12204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Smearing artifacts were observed and investigated in diffusion tensor imaging (DTI) studies of macaque monkeys on a clinical whole-body 3T scanner. METHODS Four adult macaques were utilized to evaluate DTI artifacts. DTI images were acquired with a single-shot echo-planar imaging (EPI) sequence using a parallel imaging technique. RESULTS The smearing artifacts observed on the diffusion-weighted images and fractional anisotropy maps were caused by the incomplete fat suppression due to the irregular macaque frontal skull geometry and anatomy. The artifact can be reduced substantially using a novel three-dimensional (3D) shimming procedure. CONCLUSION The smearing artifacts observed on diffusion weighted images and fractional anisotropy (FA) maps of macaque brains can be reduced substantially using a robust 3D shimming approach. The DTI protocol combined with the shimming procedure could be a robust approach to examine brain connectivity and white matter integrity of non-human primates using a conventional clinical setting.
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Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | | | - Xiaodong Zhong
- MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, USA
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17
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Carey AN, Liu X, Mintzopoulos D, Paris JJ, McLaughlin JP, Kaufman MJ. Conditional Tat protein brain expression in the GT-tg bigenic mouse induces cerebral fractional anisotropy abnormalities. Curr HIV Res 2015; 13:3-9. [PMID: 25619988 DOI: 10.2174/1570162x13666150126125244] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 01/08/2015] [Accepted: 01/21/2015] [Indexed: 11/22/2022]
Abstract
Cerebral white matter changes including tissue water diffusion abnormalities detected with diffusion tensor magnetic resonance imaging (DTI) are commonly found in humans with Human Immunodeficiency Virus (HIV) infection, as well as in animal models of the disorder. The severities of some of these abnormalities have been reported to correlate with measures of disease progression or severity, or with the degree of cognitive dysfunction. Accordingly, DTI may be a useful translational biomarker. HIV-Tat protein appears to be an important factor in the viral pathogenesis of HIV-associated neurotoxicity. We previously reported cerebral gray matter density reductions in the GT-tg bigenic mouse treated with doxycycline (Dox) to conditionally induce Tat protein expression. Presently, we administered intraperitoneal (i.p.) Dox (100 mg/kg/day) for 7 days to GT-tg mice to determine whether induction of conditional Tat expression led to the development of cerebral DTI abnormalities. Perfused and fixed brains from eight GT-tg mice administered Dox and eight control mice administered saline i.p. were extracted and underwent DTI scans on a 9.4 Tesla scanner. A whole brain analysis detected fractional anisotropy (FA) reductions in several areas including insular and endopiriform regions, as well as within the dorsal striatum. These findings suggest that exposure to Tat protein is sufficient to induce FA abnormalities, and further support the use of the GT-tg mouse to model some effects of HIV.
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Affiliation(s)
- Amanda N Carey
- Department of Psychology, Simmons College, 300 The Fenway, Boston, MA 02115, USA.
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18
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Tang Z, Dong E, Liu J, Liu Z, Wei W, Wang B, Li H, Tian J. Longitudinal assessment of fractional anisotropy alterations caused by simian immunodeficiency virus infection: a preliminary diffusion tensor imaging study. J Neurovirol 2015; 22:231-9. [DOI: 10.1007/s13365-015-0388-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/08/2015] [Accepted: 09/21/2015] [Indexed: 01/02/2023]
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19
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Li J, Wu G, Wen Z, Zhang J, Lei H, Gui X, Lin F. White Matter Development is Potentially Influenced in Adolescents with Vertically Transmitted HIV Infections: A Tract-Based Spatial Statistics Study. AJNR Am J Neuroradiol 2015; 36:2163-9. [PMID: 26228880 DOI: 10.3174/ajnr.a4417] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Accepted: 02/25/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Convergent evidence indicates that HIV is associated with abnormal WM microstructure in adults. However, little is known about whether HIV affects WM development in adolescents. In this study, we used DTI to investigate the integrity of WM microstructure in adolescents with vertically transmitted HIV infections. MATERIALS AND METHODS Fifteen HIV-positive adolescents with vertically transmitted infections and 26 HIV-negative controls participated in this study. Whole-brain analysis of fractional anisotropy was performed by Tract-Based Spatial Statistics to localize abnormal WM regions between groups. VOI analysis was further performed to explore the changes in diffusivity indices in the regions with fractional anisotropy alterations. Correlation analyses were used to assess the relationship between fractional anisotropy alterations and clinical measures within the HIV-positive group. RESULTS Relative to HIV-negative controls, HIV-positive adolescents demonstrated significantly reduced fractional anisotropy in the corpus callosum, superior and posterior corona radiata, frontal and parietal WM, pre-/postcentral gyrus, and superior longitudinal fasciculus. In the affected regions, fractional anisotropy reductions were caused by an increase in radial diffusivity, and no changes were observed in axial diffusivity. Moreover, fractional anisotropy values in the bilateral frontal WM were negatively correlated with the duration of highly active antiretroviral therapy and were positively associated with the age at onset of highly active antiretroviral therapy. CONCLUSIONS These findings suggest that early HIV infections may affect WM development, especially in the frontal WM, corpus callosum, and corona radiata in adolescents, which may be associated with hypomyelination and demyelination. Moreover, WM integrity may serve as a potential new treatment target.
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Affiliation(s)
- J Li
- From the Departments of Magnetic Resonance Imaging (J.L., G.W., Z.W., J.Z.)
| | - G Wu
- From the Departments of Magnetic Resonance Imaging (J.L., G.W., Z.W., J.Z.)
| | - Z Wen
- From the Departments of Magnetic Resonance Imaging (J.L., G.W., Z.W., J.Z.)
| | - J Zhang
- From the Departments of Magnetic Resonance Imaging (J.L., G.W., Z.W., J.Z.)
| | - H Lei
- National Center for Magnetic Resonance in Wuhan (H.L., F.L.), State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China
| | - X Gui
- Infectious Diseases (X.G.), Zhongnan Hospital of Wuhan University, Wuhan, China
| | - F Lin
- National Center for Magnetic Resonance in Wuhan (H.L., F.L.), State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
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20
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White matter microstructure among youth with perinatally acquired HIV is associated with disease severity. AIDS 2015; 29:1035-44. [PMID: 26125138 DOI: 10.1097/qad.0000000000000648] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We investigated whether HIV disease severity was associated with alterations in structural brain connectivity, and whether those alterations in turn were associated with cognitive deficits in youth with perinatally acquired HIV (PHIV). DESIGN PHIV youth (n = 40) from the Pediatric HIV/AIDS Cohort Study (PHACS) (mean age: 16 ± 2 years) were included to evaluate how current and past disease severity measures (recent/nadir CD4%; peak viral load) relate to white matter microstructure within PHIV youth. PHIV youth were compared with 314 controls from the Pediatric Imaging, Neurocognition and Genetics (PING) study. METHODS Diffusion tensor imaging and tractography were utilized to assess white matter microstructure. Mediation analyses were conducted to examine whether microstructure alterations contributed to relationships between higher disease severity and specific cognitive domains in PHIV youth. RESULTS Whole brain fractional anisotropy was reduced, but radial and mean diffusivity were increased in PHIV compared with control youth. Within PHIV youth, more severe past HIV disease was associated with reduced fractional anisotropy of the right inferior fronto-occipital (IFO) and left uncinate tracts; elevated mean diffusivity of the F minor; and increased streamlines comprising the left inferior longitudinal fasciculus (ILF). Associations of higher peak viral load with lower working memory performance were partly mediated by reductions in right IFO fractional anisotropy levels. CONCLUSION Our findings suggest that PHIV youth have a higher risk of alterations in white matter microstructure than typically developing youth, and certain alterations are related to past disease severity. Further, white matter alterations potentially mediate associations between HIV disease and working memory.
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Abstract
PURPOSE OF REVIEW HIV enters the brain after initial infection, and with time can lead to HIV-associated neurocognitive disorders (HAND). Although the introduction of combination antiretroviral therapy has reduced the more severe forms of HAND, milder forms are still highly prevalent. The 'gold standard' for HAND diagnosis remains detailed neuropsychological performance testing but additional biomarkers (including neuroimaging) may assist in early detection of HAND. RECENT FINDINGS We review the application of recently developed noninvasive MRI and PET techniques in HIV+ individuals. In particular, magnetic resonance spectroscopy may be more sensitive than conventional MRI alone in detecting HIV associated changes. Diffusion tensor imaging has become increasingly popular for assessing changes in white matter structural integrity due to HIV. Both functional MRI and PET have been limitedly performed but could provide keys for characterizing neuropathophysiologic changes due to HIV. SUMMARY It is hoped that continued progress will allow novel neuroimaging methods to be included in future HAND management guidelines.
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22
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Li CX, Herndon JG, Novembre FJ, Zhang X. A longitudinal magnetization transfer imaging evaluation of brain injury in a macaque model of neuroAIDS. AIDS Res Hum Retroviruses 2015; 31:335-41. [PMID: 25376011 DOI: 10.1089/aid.2014.0166] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Magnetization transfer (MT) imaging has been explored in prior studies of HIV patients and showed the potential capacity to assess brain injury after HIV infection. In the present study, adult pig-tailed macaques were infected with a highly neuropathogenic virus SIVsmmFGb. MT imaging was exploited to examine the monkey brains before simian immunodeficiency virus (SIV) inoculation and 2, 4, 8, 12, 16, and 20 weeks post-SIV inoculation. Blood samples were collected from each animal for monitoring CD4(+) and CD8(+) T cells before each MRI scan. The MT ratios (MTR) in several brain regions of interest were evaluated longitudinally. Significant reductions of MTR were observed in whole brain and selected regions of interest (genu, splenium, thalamus, caudate, centrum semiovale, frontal white matter, frontal gray matter, and putamen) in the SIV-infected monkeys, consistent with those reported previously in HIV patients. In particular, the longitudinal results indicate that abnormal MTR reduction can be detected as early as in 2 weeks and MTR may be more sensitive to the brain injury in cortical regions than in subcortical regions during acute SIV infection. In addition, MTR reduction in genu, centrum semiovale, and thalamus significantly correlated with the CD4(+) T cell percentage decrease. Also, the MTR reduction in thalamus correlated with the CD8(+) T cell percentage elevation. Taken together, this study reported the longitudinal evolution of MTR in different brain regions during SIV infection and further validates previous findings in HIV patients. The preliminary results suggest that MT imaging could be a robust and sensitive approach to characterize the neurodegeneration after SIV or HIV infection.
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Affiliation(s)
- Chun-Xia Li
- 1 Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University , Atlanta, Georgia
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23
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Factors related to HIV-associated neurocognitive impairment differ with age. J Neurovirol 2014; 21:56-65. [PMID: 25404233 DOI: 10.1007/s13365-014-0296-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 09/19/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
Abstract
Over 50% of HIV-infected (HIV+) persons are expected to be over age 50 by 2015. The pathogenic effects of HIV, particularly in cases of long-term infection, may intersect with those of age-related illnesses and prolonged exposure to combined antiretroviral therapy (cART). One potential outcome is an increased prevalence of neurocognitive impairment in older HIV+ individuals, as well as an altered presentation of HIV-associated neurocognitive disorders (HANDs). In this study, we employed stepwise regression to examine 24 features sometimes associated with HAND in 40 older (55-73 years of age) and 30 younger (32-50 years of age) HIV+, cART-treated participants without significant central nervous system confounds. The features most effective in generating a true assessment of the likelihood of HAND diagnosis differed between older and younger cohorts, with the younger cohort containing features associated with drug abuse that were correlated to HAND and the older cohort containing features that were associated with lipid disorders mildly associated with HAND. As the HIV-infected population grows and the demographics of the epidemic change, it is increasingly important to re-evaluate features associated with neurocognitive impairment. Here, we have identified features, routinely collected in primary care settings, that provide more accurate diagnostic value than a neurocognitive screening measure among younger and older HIV individuals.
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Li CX, Zhang X, Komery A, Li Y, Mao H, Herndon JG, Novembre FJ. Longitudinal cerebral metabolic changes in pig-tailed macaques infected with the neurovirulent virus SIVsmmFGb. J Neurovirol 2014; 20:612-9. [PMID: 25377443 DOI: 10.1007/s13365-014-0286-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 08/20/2014] [Accepted: 08/27/2014] [Indexed: 11/26/2022]
Abstract
Longitudinal cerebral metabolite changes in pig-tailed macaques inoculated with the simian immunodeficiency virus SIVsmmFGb were evaluated with in vivo proton MRS at 3 T. Blood sample collection, and MRS were carried out before and 2, 4, 8, 12, 16, 20, and 24 weeks after SIV inoculation. Significant reduction of N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios in prefrontal gray matter (PGM) and glutamate/glutamine(Glx)/Cr ratio in striatum, and increase of myo-inositol (mI)/Cr in striatum were observed during acute SIV infection. The metabolite alterations during the SIVsmmFGb infection are largely in agreement with previous findings in other non-human primate models and HIV patients. Also, NAA/Cr in PGM and striatum and Glx/Cr in striatum are negatively correlated with the percentage of CD8+ T cells after the SIV infection, suggesting the interaction between brain metabolite and immune dysfunction. The present study complements previous studies by describing the time course of alterations of brain metabolites during SIVsmmFGb infection. The findings further demonstrate the efficacy of the SIVsmmFGb-infected macaque as a model to characterize central nervous system infection using novel neuroimaging approaches and also as a tool for exploration of novel and advanced neuroimaging techniques in HIV/AIDS studies.
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Affiliation(s)
- Chun-Xia Li
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, 954 Gatewood Rd, Atlanta, GA, 30329, USA
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Bladowska J, Knysz B, Zimny A, Małyszczak K, Kołtowska A, Szewczyk P, Gąsiorowski J, Furdal M, Sąsiadek MJ. Value of perfusion-weighted MR imaging in the assessment of early cerebral alterations in neurologically asymptomatic HIV-1-positive and HCV-positive patients. PLoS One 2014; 9:e102214. [PMID: 25013963 PMCID: PMC4094508 DOI: 10.1371/journal.pone.0102214] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 06/16/2014] [Indexed: 12/17/2022] Open
Abstract
Background and Purpose Asymptomatic central nervous system (CNS) involvement occurs in the early stage of the human immunodeficiency virus (HIV) infection. It has been documented that the hepatitis C virus (HCV) can replicate in the CNS. The aim of the study was to evaluate early disturbances in cerebral microcirculation using magnetic resonance (MR) perfusion-weighted imaging (PWI) in asymptomatic HIV-1-positive and HCV-positive patients, as well as to assess the correlation between PWI measurements and the clinical data. Materials and Methods Fifty-six patients: 17 HIV-1-positive non-treated, 18 HIV-1-positive treated with combination antiretroviral therapy (cART), 7 HIV-1/HCV-positive non-treated, 14 HCV-positive before antiviral therapy and 18 control subjects were enrolled in the study. PWI was performed with a 1.5T MR unit using dynamic susceptibility contrast (DSC) method. Cerebral blood volume (CBV) measurements relative to cerebellum (rCBV) were evaluated in the posterior cingulated region (PCG), basal ganglia (BG), temporoparietal (TPC) and frontal cortices (FC), as well as in white matter of frontoparietal areas. Correlations of rCBV values with immunologic data and liver histology activity index (HAI) were analyzed. Results Significantly lower rCBV values were found in the right TPC and left FC as well as in PCG in HIV-1-positive naïve (p = 0.009; p = 0.020; p = 0.012), HIV-1 cART treated (p = 0.007; p = 0.009; p = 0.033), HIV-1/HCV-positive (p = 0.007; p = 0.027; p = 0.045) and HCV-positive patients (p = 0.010; p = 0.005; p = 0.045) compared to controls. HIV-1-positive cART treated and HIV-1/HCV-positive patients demonstrated lower rCBV values in the right FC (p = 0.009; p = 0.032, respectively) and the left TPC (p = 0.036; p = 0.005, respectively), while HCV-positive subjects revealed lower rCBV values in the left TPC region (p = 0.003). We found significantly elevated rCBV values in BG in HCV-positive patients (p = 0.0002; p<0.0001) compared to controls as well as to all HIV-1-positive subjects. There were no significant correlations of rCBV values and CD4 T cell count or HAI score. Conclusions PWI examination enables the assessment of HIV-related as well as HCV-related early cerebral dysfunction in asymptomatic subjects. HCV-infected patients seem to reveal the most pronounced perfusion changes.
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Affiliation(s)
- Joanna Bladowska
- Department of General Radiology, Interventional Radiology and Neuroradiology, Chair of Radiology, Wroclaw Medical University, Wroclaw, Poland
- * E-mail:
| | - Brygida Knysz
- Department of Infectious Diseases, Liver Diseases and Acquired Immune Deficiency, Wroclaw Medical University, Wroclaw, Poland
| | - Anna Zimny
- Department of General Radiology, Interventional Radiology and Neuroradiology, Chair of Radiology, Wroclaw Medical University, Wroclaw, Poland
| | - Krzysztof Małyszczak
- Division of Psychotherapy and Psychosomatic Medicine, Department of Psychiatry, Wroclaw Medical University, Wrocław, Poland
| | - Anna Kołtowska
- Department of General Radiology, Interventional Radiology and Neuroradiology, Chair of Radiology, Wroclaw Medical University, Wroclaw, Poland
| | - Paweł Szewczyk
- Department of General Radiology, Interventional Radiology and Neuroradiology, Chair of Radiology, Wroclaw Medical University, Wroclaw, Poland
| | - Jacek Gąsiorowski
- Department of Infectious Diseases, Liver Diseases and Acquired Immune Deficiency, Wroclaw Medical University, Wroclaw, Poland
| | - Michał Furdal
- Regional Specialistic Hospital, Department of Cardiology, Wroclaw, Poland
| | - Marek J. Sąsiadek
- Department of General Radiology, Interventional Radiology and Neuroradiology, Chair of Radiology, Wroclaw Medical University, Wroclaw, Poland
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Meng Y, Zhang X. In vivo diffusion spectrum imaging of non-human primate brain: initial experience in transcallosal fiber examination. Quant Imaging Med Surg 2014; 4:129-35. [PMID: 24834425 DOI: 10.3978/j.issn.2223-4292.2014.04.05] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/21/2014] [Indexed: 12/12/2022]
Abstract
In comparison with conventional diffusion tensor imaging (DTI) technique, diffusion spectrum imaging (DSI) allows for delineating crossing and touching fibers in the brain and has been explored in clinical and preclinical studies. Non-human primates (NHPs) resemble most aspects of human and are widely employed in various neuroscience researches and pharmaceutical development. In the present study, a parallel imaging-based DSI protocol was implemented for in vivo fiber tracking of macaque monkey brains on a 3.0 T clinical scanner. Transcallosal fiber tracts of adult macaque brains were examined with DSI and compared with those from a a conventional DTI protocol. The results demonstrate that DSI can reveal the transcallosal fiber bundles much more extensively than the conventional DTI. The preliminary results suggest that DSI may provide a feasible and robust approach for characterizing the fiber pathways in various disease models of NHPs.
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Affiliation(s)
- Yuguang Meng
- 1 Yerkes Imaging Center, 2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA
| | - Xiaodong Zhang
- 1 Yerkes Imaging Center, 2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA
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Zhang X, Tong F, Li CX, Yan Y, Nair G, Nagaoka T, Tanaka Y, Zola S, Howell L. A fast multiparameter MRI approach for acute stroke assessment on a 3T clinical scanner: preliminary results in a non-human primate model with transient ischemic occlusion. Quant Imaging Med Surg 2014; 4:112-22. [PMID: 24834423 DOI: 10.3978/j.issn.2223-4292.2014.04.06] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/21/2014] [Indexed: 11/14/2022]
Abstract
Many MRI parameters have been explored and demonstrated the capability or potential to evaluate acute stroke injury, providing anatomical, microstructural, functional, or neurochemical information for diagnostic purposes and therapeutic development. However, the application of multiparameter MRI approach is hindered in clinic due to the very limited time window after stroke insult. Parallel imaging technique can accelerate MRI data acquisition dramatically and has been incorporated in modern clinical scanners and increasingly applied for various diagnostic purposes. In the present study, a fast multiparameter MRI approach including structural T1-weighted imaging (T1W), T2-weighted imaging (T2W), diffusion tensor imaging (DTI), T2-mapping, proton magnetic resonance spectroscopy, cerebral blood flow (CBF), and magnetization transfer (MT) imaging, was implemented and optimized for assessing acute stroke injury on a 3T clinical scanner. A macaque model of transient ischemic stroke induced by a minimal interventional approach was utilized for evaluating the multiparameter MRI approach. The preliminary results indicate the surgical procedure successfully induced ischemic occlusion in the cortex and/or subcortex in adult macaque monkeys (n=4). Application of parallel imaging technique substantially reduced the scanning duration of most MRI data acquisitions, allowing for fast and repeated evaluation of acute stroke injury. Hence, the use of the multiparameter MRI approach with up to five quantitative measures can provide significant advantages in preclinical or clinical studies of stroke disease.
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Affiliation(s)
- Xiaodong Zhang
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Frank Tong
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Chun-Xia Li
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Yumei Yan
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Govind Nair
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Tsukasa Nagaoka
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Yoji Tanaka
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Stuart Zola
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Leonard Howell
- 1 Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA ; 2 Department of Radiology, School of Medicine, Emory University, Atlanta, GA 30322, USA ; 3 the Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA 30322, USA ; 4 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA ; 5 Sony Corporation, Tokyo, Japan ; 6 Department of Neurosurgery, Tokyo Medical and Dental University, Tokyo, Japan ; 7 Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA 30322, USA
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Masters MC, Ances BM. Role of neuroimaging in HIV-associated neurocognitive disorders. Semin Neurol 2014; 34:89-102. [PMID: 24715492 DOI: 10.1055/s-0034-1372346] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human immunodeficiency virus (HIV) enters the brain soon after seroconversion and can cause HIV-associated neurocognitive disorders (HAND). Although the more severe and progressive forms of HAND are less prevalent due to combination antiretroviral therapy (cART), ∼ 40% of HIV-infected (HIV+) patients continue to have cognitive impairment. Some HIV+ individuals who have effective plasma HIV-1 RNA suppression with cART still develop HAND. It is often difficult to diagnose HAND in the outpatient setting as detailed neuropsychological performance testing is required. Additional biomarkers that are relatively easy to obtain and clinically relevant are needed for assessing HIV-associated neuropathologic changes. Recently developed noninvasive magnetic resonance imaging (MRI) techniques have great potential to serve as biomarkers. The authors review the application of some of these neuroimaging techniques, magnetic resonance spectroscopy (MRS), volumetric MRI, diffusion tensor imaging (DTI), functional MRI (fMRI), in HIV+ individuals. Each of the neuroimaging methods offers unique insight into mechanisms underlying neuroHIV, could monitor disease progression, and may assist in evaluating the efficacy of particular cART regimens. It is hoped that considerable progress will continue to occur such that some of these neuroimaging methods will be incorporated across multiple sites and included in future HAND guidelines.
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Affiliation(s)
- Mary C Masters
- Department of Neurology, School of Medicine, Washington University in St Louis, St Louis, Missouri
| | - Beau M Ances
- Department of Neurology, School of Medicine, Washington University in St Louis, St Louis, Missouri
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Abstract
Multiple MRI modalities including Diffusion Tensor Imaging (DTI), perfusion MRI, in vivo MR Spectroscopy (MRS), volumetric MRI, contrast-enhanced MRI, and functional MRI have demonstrated abnormalities of the structural and functional integrity as well as neurochemical alterations of the HIV-infected central nervous system (CNS). MRI has been proposed as a robust imaging approach for the characterization of the stage of progression in HIV infection. However, the interpretation of the MRI findings of HIV patients is complicated by the fact that these clinical studies cannot readily be controlled. Simian immunodeficiency virus (SIV) infected macaques exhibit neuropathological symptoms similar to those of HIV patients, and are an important model for studying the course of CNS infection, cognitive impairment, and neuropathology of HIV disease as well as treatment efficacy. MRI of non-human primates (NHPs) is of limited benefit on most clinical scanners operating at or below 1.5 Tesla because this low field strength does not produce high-quality images of the relatively small NHP brain. Contemporary high field MRI (3T or more) for clinical use provides impressive sensitivity for magnetic resonance signal detection and is now accessible in many imaging centers and hospitals, facilitating the use of various MRI techniques in NHP studies. In this article, several high field MRI techniques and applications in macaque models of neuroAIDS are reviewed and the relation between quantitative MRI measures and blood T-cell alterations is discussed.
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Affiliation(s)
- Xiaodong Zhang
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA ; Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA
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Abstract
OBJECTIVE HIV preferentially affects white matter in the brain. Although combination antiretroviral therapy (cART) reduces HIV viral load within the brain, continued inflammation can persist. We investigated the effect of HIV and cART on white matter integrity. DESIGN We used diffusion tensor imaging (DTI) to examine the effects of HIV and cART on white matter integrity within the corpus callosum and centrum semiovale (CSO). METHODS Neuropsychological testing and DTI measures (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were obtained from 21 HIV-uninfected controls, 21 HIV-infected patients naive to cART (HIV+/cART-), and 21 HIV+ patients receiving stable cART (HIV+/cART+). A subset of the HIV+/cART- individuals (n=10) was assessed before and 6 months after receiving medications. Differences among the cross-sectional groups were assessed using an analysis of variance, whereas paired t-tests evaluated longitudinal changes. RESULTS HIV+/cART- participants had significantly lower mean diffusivity, axial diffusivity, and radial diffusivity for the corpus callosum and CSO compared to HIV- controls and HIV+/cART+ individuals. No significant difference existed between HIV- controls and HIV+/cART+ patients. cART initiation significantly improved mean diffusivity, radial diffusivity, and axial diffusivity, but not fractional anisotropy, in the corpus callosum and CSO in some HIV-infected patients. CONCLUSION Observed decreases in DTI parameters between HIV+/cART+ and HIV+/cART- individuals could reflect the presence of inflammatory cells or cytotoxic edema in HIV+/cART- patients. Initiating cART could lead to a reduction in neuro-inflammation and improvement in DTI measures. Future DTI studies may be useful for evaluating the efficacy higher brain penetrating cART regimens.
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