627 results match your criteria: "Gordon center for medical imaging[Affiliation]"

Background: Transcranial temporal interference stimulation (tTIS) is a new, emerging neurostimulation technology that utilizes two or more electric fields at specific frequencies to modulate the oscillations of neurons at a desired spatial location in the brain. The physics of tTIS offers the advantage of modulating deep brain structures in a non-invasive fashion and with minimal stimulation of the overlying cortex outside of a selected target. As such, tTIS can be effectively employed in the context of therapeutics for the psychiatric disease of disrupted brain connectivity, such as major depressive disorder (MDD).

View Article and Find Full Text PDF

Investigating muscle coordination patterns with Granger causality analysis in protrusive motion from tagged and diffusion MRI.

JASA Express Lett

September 2024

Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.

The human tongue exhibits an orchestrated arrangement of internal muscles, working in sequential order to execute tongue movements. Understanding the muscle coordination patterns involved in tongue protrusive motion is crucial for advancing knowledge of tongue structure and function. To achieve this, this work focuses on five muscles known to contribute to protrusive motion.

View Article and Find Full Text PDF

Understanding the relationship between tongue motion patterns during speech and their resulting speech acoustic outcomes-i.e., articulatory-acoustic relation-is of great importance in assessing speech quality and developing innovative treatment and rehabilitative strategies.

View Article and Find Full Text PDF

Lysosome-Targeted Bifunctional Therapeutics Induce Autodynamic Cancer Therapy.

Adv Sci (Weinh)

November 2024

Department of Materials Science and Engineering, Chonnam National University, Gwangju, 61186, Republic of Korea.

Autodynamic cancer therapy possesses tremendous potential for enhancing therapeutic efficacy by initiating the treatment process autonomously within targeted cells. However, challenges related to biocompatibility and targeted delivery have hindered its clinical translation owing to the induction of adverse effects and cytotoxicity in healthy cells. In this study, a novel approach for auto-initiated dynamic therapy by conjugating zwitterionic near-infrared fluorophores to a cell-penetrating peptide is proposed.

View Article and Find Full Text PDF

Background: Transcranial alternating current stimulation (tACS) alters cortical excitability with low-intensity alternating current and thereby modulates aberrant brain oscillations. Despite the recent increase in studies investigating the feasibility and efficacy of tACS in treating neuropsychiatric disorders, its mechanisms, as well as optimal stimulation parameters, are not fully understood.

Objectives: This systematic review aimed to compile human research on tACS for neuropsychiatric disorders to delineate typical treatment parameters for these conditions and evaluate its outcomes.

View Article and Find Full Text PDF

Copper (Cu) is widely used as an industrial electrode due to its high electrical conductivity, mechanical properties, and cost-effectiveness. However, Cu is susceptible to corrosion, which degrades device performance over time. Although various methods (alloying, physical passivation, surface treatment, etc.

View Article and Find Full Text PDF

Background: Postoperative delirium is the most common complication following surgery among older adults, and has been consistently associated with increased mortality and morbidity, cognitive decline, and loss of independence, as well as markedly increased health-care costs. Electroencephalography (EEG) spectral slowing has frequently been observed during episodes of delirium, whereas intraoperative frontal alpha power is associated with postoperative delirium. We sought to identify preoperative predictors that could identify individuals at high risk for postoperative delirium, which could guide clinical decision-making and enable targeted interventions to potentially decrease delirium incidence and postoperative delirium-related complications.

View Article and Find Full Text PDF

Retraction: Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids.

Nat Prod Rep

September 2024

Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, 125 Nashua Street, Suite 660, Boston, Massachusetts 02114, USA.

Retraction of 'Recent advances in total synthesis of protoberberine and chiral tetrahydroberberine alkaloids' by Zhen-Xi Niu , , 2024, https://doi.org/10.1039/d4np00016a.

View Article and Find Full Text PDF

Atrial fibrillation (AFib) and the risk of its lethal complications are propelled by fibrosis, which induces electrical heterogeneity and gives rise to reentry circuits. Atrial TREM2 macrophages secrete osteopontin (encoded by ), a matricellular signaling protein that engenders fibrosis and AFib. Here we show that silencing in TREM2 cardiac macrophages with an antibody-siRNA conjugate reduces atrial fibrosis and suppresses AFib in mice, thus offering a new immunotherapy for the most common arrhythmia.

View Article and Find Full Text PDF

Nanotherapeutic kidney cell-specific targeting to ameliorate acute kidney injury.

Kidney Int

October 2024

Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, Oregon, USA; Operative Care Division, Portland VA Medical Center, Portland, Oregon, USA. Electronic address:

Acute kidney injury (AKI) increases the risk of in-hospital death, adds to expense of care, and risk of early chronic kidney disease. AKI often follows an acute event such that timely treatment could ameliorate AKI and potentially reduce the risk of additional disease. Despite therapeutic success of dexamethasone in animal models, clinical trials have not demonstrated broad success.

View Article and Find Full Text PDF

Harmonizing tau positron emission tomography in Alzheimer's disease: The CenTauR scale and the joint propagation model.

Alzheimers Dement

September 2024

Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, Victoria, Australia.

Introduction: Tau-positron emission tomography (PET) outcome data of patients with Alzheimer's disease (AD) cannot currently be meaningfully compared or combined when different tracers are used due to differences in tracer properties, instrumentation, and methods of analysis.

Methods: Using head-to-head data from five cohorts with tau PET radiotracers designed to target tau deposition in AD, we tested a joint propagation model (JPM) to harmonize quantification (units termed "CenTauR" [CTR]). JPM is a statistical model that simultaneously models the relationships between head-to-head and anchor point data.

View Article and Find Full Text PDF

Machine learning classification of functional neurological disorder using structural brain MRI features.

J Neurol Neurosurg Psychiatry

July 2024

Functional Neurological Disorder Research Group, Division of Behavioral Neurology & Integrated Brain Medicine, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA

Background: Brain imaging studies investigating grey matter in functional neurological disorder (FND) have used univariate approaches to report group-level differences compared with healthy controls (HCs). However, these findings have limited translatability because they do not differentiate patients from controls at the individual-level.

Methods: 183 participants were prospectively recruited across three groups: 61 patients with mixed FND (FND-mixed), 61 age-matched and sex-matched HCs and 61 age, sex, depression and anxiety-matched psychiatric controls (PCs).

View Article and Find Full Text PDF

In 2D noble metals like copper, the carrier scattering at grain boundaries has obscured the intrinsic nature of electronic transport. However, it is demonstrated that the intrinsic nature of transport by hole carriers in 2D copper can be revealed by growing thin films without grain boundaries. As even a slight deviation from the twin boundary is perceived as grain boundaries by electrons, it is only through the thorough elimination of grain boundaries that the hidden hole-like attribute of 2D single-crystal copper can be unmasked.

View Article and Find Full Text PDF

Lower Locus Coeruleus Integrity Signals Elevated Entorhinal Tau and Clinical Progression in Asymptomatic Older Individuals.

Ann Neurol

October 2024

Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, The Netherlands.

Objective: Elevated entorhinal cortex (EC) tau in low beta-amyloid individuals can predict accumulation of pathology and cognitive decline. We compared the accuracy of magnetic resonance imaging (MRI)-derived locus coeruleus integrity, neocortical beta-amyloid burden by positron emission tomography (PET), and hippocampal volume in identifying elevated entorhinal tau signal in asymptomatic individuals who are considered beta-amyloid PET-negative.

Methods: We included 188 asymptomatic individuals (70.

View Article and Find Full Text PDF

[This corrects the article DOI: 10.3389/fimmu.2022.

View Article and Find Full Text PDF

Alzheimer's Disease (AD) is characterized by structural and functional dysfunction involving the Default Mode Network (DMN), for which the Precuneus (PC) is a key node. We proposed a randomized double-blind pilot study to determine neurobiological changes after 24 weeks of PC-rTMS in patients with mild-to-moderate AD. Sixteen patients were randomly assigned to SHAM or PC-rTMS, and received an intensive 2-weeks course with daily rTMS sessions, followed by a maintenance phase in which rTMS has been applied once a week.

View Article and Find Full Text PDF

Head and neck tumor segmentation from [F]F-FDG PET/CT images based on 3D diffusion model.

Phys Med Biol

July 2024

J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, United States of America.

Head and neck (H&N) cancers are among the most prevalent types of cancer worldwide, and [F]F-FDG PET/CT is widely used for H&N cancer management. Recently, the diffusion model has demonstrated remarkable performance in various image-generation tasks. In this work, we proposed a 3D diffusion model to accurately perform H&N tumor segmentation from 3D PET and CT volumes.

View Article and Find Full Text PDF

Positron emission tomography (PET) imaging employs positron-emitting radioisotopes to visualize biological processes in living subjects with high sensitivity and quantitative accuracy. As the most translational molecular imaging modality, PET can detect and image a wide range of radiotracers with minimal or no modification to parent drugs or targeting molecules. This Perspective provides a comprehensive analysis of developing PET radioligands using allosteric modulators for the metabotropic glutamate receptor subtype 4 (mGluR4) as a therapeutic target for neurological disorders.

View Article and Find Full Text PDF

The development of novel compounds for tissue-specific targeting and imaging is often impeded by a lack of lead compounds and the availability of reliable chemistry. Automated chemical synthesis systems provide a potential solution by enabling reliable, repeated access to large compound libraries for screening. Here we report an integrated solid-phase combinatorial chemistry system created using commercial and customized robots.

View Article and Find Full Text PDF

Background: There is good evidence that elevated amyloid-β (Aβ) positron emission tomography (PET) signal is associated with cognitive decline in clinically normal (CN) individuals. However, it is less well established whether there is an association between the Aβ burden and decline in daily living activities in this population. Moreover, Aβ-PET Centiloids (CL) thresholds that can optimally predict functional decline have not yet been established.

View Article and Find Full Text PDF

Lower in vivo locus coeruleus integrity is associated with lower cortical thickness in older individuals with elevated Alzheimer's pathology: a cohort study.

Alzheimers Res Ther

June 2024

The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02129, USA.

Background: Autopsy work indicates that the widely-projecting noradrenergic pontine locus coeruleus (LC) is among the earliest regions to accumulate hyperphosphorylated tau, a neuropathological Alzheimer's disease (AD) hallmark. This early tau deposition is accompanied by a reduced density of LC projections and a reduction of norepinephrine's neuroprotective effects, potentially compromising the neuronal integrity of LC's cortical targets. Previous studies suggest that lower magnetic resonance imaging (MRI)-derived LC integrity may signal cortical tissue degeneration in cognitively healthy, older individuals.

View Article and Find Full Text PDF

Tau propagation in the brain olfactory circuits is associated with smell perception changes in aging.

Nat Commun

June 2024

Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.

Article Synopsis
  • The study explores how olfactory pathways are linked to memory-related areas of the brain, suggesting a potential role in the progression of Alzheimer's disease (AD).
  • Researchers analyzed olfactory identification along with neuroimaging techniques and genetic data from 89 cognitively normal older adults to understand how AD-related tau pathology spreads.
  • Results show that deficits in odor identification are tied to tau buildup in the olfactory system, indicating that tau progresses from the medial temporal lobe to the olfactory regions rather than the other way around, with certain genetic factors possibly increasing susceptibility to this process.
View Article and Find Full Text PDF

Background: Autopsy work reported that neuronal density in the locus coeruleus (LC) provides neural reserve against cognitive decline in dementia. Recent neuroimaging and pharmacological studies reported that left frontoparietal network functional connectivity (LFPN-FC) confers resilience against beta-amyloid (Aβ)-related cognitive decline in preclinical sporadic and autosomal dominant Alzheimer's disease (AD), as well as against LC-related cognitive changes. Given that the LFPN and the LC play important roles in attention, and attention deficits have been observed early in the disease process, we examined whether LFPN-FC and LC structural health attenuate attentional decline in the context of AD pathology.

View Article and Find Full Text PDF

Unexpected Intermolecular C-H···O Hydrogen Bonds and H NMR Chemical Shifts in a Key Linker for Fluorine-18 Labeling of Dimeric Drugs.

J Phys Chem B

June 2024

Department of Chemistry and Chemical Biology, Institute for Quantitative Biomedicine, Rutgers University, Piscataway, New Jersey 08854, United States.

The compound 2-{[(trifluoromethyl)sulfonyl]oxy}propane-1,3-diyl bis(4-methylbenzenesulfonate) (TPB) is a crucial intermediate in the synthesis of F-radiolabeled cromolyn derivatives. In this work, we combine H NMR spectroscopy, X-ray crystallography, ab initio molecular dynamics, and NMR calculations to examine the structure, interactions, and solvation dynamics of the TPB molecule. In CDCl, the CH groups within its glyceryl-derived linker exhibit a single set of proton signals in the H NMR measurements.

View Article and Find Full Text PDF

The Pathophysiological Underpinnings of Gamma-Band Alterations in Psychiatric Disorders.

Life (Basel)

April 2024

Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA.

Investigating the biophysiological substrates of psychiatric illnesses is of great interest to our understanding of disorders' etiology, the identification of reliable biomarkers, and potential new therapeutic avenues. Schizophrenia represents a consolidated model of γ alterations arising from the aberrant activity of parvalbumin-positive GABAergic interneurons, whose dysfunction is associated with perineuronal net impairment and neuroinflammation. This model of pathogenesis is supported by molecular, cellular, and functional evidence.

View Article and Find Full Text PDF