Purpose: To develop a relevant pathophysiologic model of human immunodeficiency virus (HIV)-associated dementia by studying regional variations in metabolite levels measured with magnetic resonance (MR) spectroscopic imaging and their relationship to immunologic measures and cognitive dysfunction.
Materials And Methods: This was a HIPAA-compliant, institutional review board-approved study involving written informed consent. Distributions of N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) concentrations in 94 subjects (20 seronegative controls and 74 HIV-positive subjects; 34 of the HIV-positive subjects having HIV-associated dementia; 63 men, 31 women; mean age, 40 years) were determined with proton (hydrogen 1 [(1)H]) MR spectroscopic imaging. HIV-positive subjects underwent neuropsychological testing and blood and cerebrospinal fluid (CSF) analysis. Factor analysis was utilized to determine associations between metabolites across regions. Analysis of variance and t tests were used to isolate differences between cohorts.
Results: A "Cho factor" differentiated seronegative controls from HIV-infected cohorts, indicating elevated Cho levels across deep gray and white matter regions of HIV-positive individuals. An "NAA factor" differentiated those with dementia from those without and correlated best with psychomotor and executive function tests. A "Cr factor" indicated Cr elevations correlated with CSF monocyte chemoattractant protein-1 levels. NAA and Cr factor scores were strongly weighted to metabolite changes in white matter regions.
Conclusion: These results highlight the importance of white matter involvement in HIV-associated dementia and support the current pathogenesis model of glial cell proliferation in HIV infection, denoted by regional Cho elevations, and neuronal dysfunction and/or death, denoted by NAA decreases, associated with dementia. Factor analysis of MR spectroscopic imaging data is a useful method for determining regional metabolic variations in HIV infection and its neuropsychological correlates.
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http://dx.doi.org/10.1148/radiol.09081867 | DOI Listing |
Anal Chim Acta
January 2025
College of Tobacco Science, Henan Agricultural University, Zhengzhou, 450046, China. Electronic address:
Background: Nitroxyl (HNO) is an emerging signaling molecule that plays a significant regulatory role in various aspects of plant biology, including stress responses and developmental processes. However, understanding the precise actions of HNO in plants has been challenging due to the absence of highly sensitive and real-time in situ monitoring tools. Consequently, it is crucial to develop effective and accurate detection methods for HNO.
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February 2025
MR Methodology, Department for Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland.
The purpose of this study was to produce metabolite-specific T and concentration maps in a clinically compatible time frame. A multi-TE 2D MR spectroscopic imaging (MRSI) experiment (multi-echo single-shot MRSI [MESS-MRSI]) deployed truncated and partially sampled multi-echo trains from single scans and was combined with simultaneous multiparametric model fitting. It was tested in vivo for the brain in five healthy subjects.
View Article and Find Full Text PDFBioengineering (Basel)
December 2024
Optical Imaging Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA.
A mammalian breath-hold (BH) mechanism can induce vasoconstriction in the limbs, altering blood flow and oxygenation flow changes in a wound site. Our objective was to utilize a BH paradigm as a stimulus to induce peripheral tissue oxygenation changes via studies on control and diabetic foot ulcer (DFU) subjects. Subjects were imaged under a breath-hold paradigm (including 20 s BH) using a non-contact spatio-temporal-based NIRS device.
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December 2024
Smart Food Manufacturing Project Group, Korea Food Research Institute, Wanju 55365, Republic of Korea.
Seafood quality preservation remains a critical focus in the food industry, particularly as the freeze-thaw process significantly impacts the freshness and safety of aquatic products. This study investigated quality changes in frozen mackerel subjected to two thawing methods, room temperature (RT) and running water (WT), and assessed the potential of hyperspectral imaging (HSI) for classifying these methods. After thawing, mackerel samples were stored at 5 °C for 21 days, with physicochemical, textural, and spectroscopic analyses tracking quality changes and supporting the development of a spectroscopic classification model.
View Article and Find Full Text PDFNMR Biomed
February 2025
Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA.
Cellular metabolism is inextricably linked to transmembrane levels of proton (H), sodium (Na), and potassium (K) ions. Although reduced sodium-potassium pump (Na-K ATPase) activity in tumors directly disturbs transmembrane Na and K levels, this dysfunction is a result of upregulated aerobic glycolysis generating excessive cytosolic H (and lactate) which are extruded to acidify the interstitial space. These oncogene-directed metabolic changes, affecting intracellular Na and H, can be further exacerbated by upregulation of ion exchangers/transporters.
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