Comparison between USPIOs and SPIOs for Multimodal Imaging of Extracellular Vesicles Extracted from Adipose Tissue-Derived Adult Stem Cells.

Adipose tissue-derived adult stem (ADAS) cells and extracellular vesicle (EV) therapy offer promising avenues for treating neurodegenerative diseases due to their accessibility and potential for autologous cell transplantation. However, the clinical application of ADAS cells or EVs is limited by the challenge of precisely identifying them in specific regions of interest. This study compares two superparamagnetic iron oxide nanoparticles, differing mainly in size, to determine their efficacy for allowing non-invasive ADAS tracking via MRI/MPI and indirect labeling of EVs.

Very-long T2-weighted imaging of the non-lesional brain tissue in multiple sclerosis patients.

The purpose of this study is to demonstrate that T2-weighted imaging with very long echo time (TE > 300 ms) can provide relevant information in neurodegenerative/inflammatory disorder. Twenty patients affected by relapsing-remitting multiple sclerosis with stable disease course underwent 1.5 T 3D FLAIR, 3D T1-weighted, and a multi-echo sequence with 32 echoes (TE = 10-320 ms).

Injectable Thermogelling Nanostructured Ink as Simultaneous Optical and Magnetic Resonance Imaging Contrast Agent for Image-Guided Surgery.

The development of efficient and biocompatible contrast agents is particularly urgent for modern clinical surgery. Nanostructured materials raised great interest as contrast agents for different imaging techniques, for which essential features are high contrasts, and in the case of precise clinical surgery, minimization of the signal spatial dispersion when embedded in biological tissues. This study deals with the development of a multimodal contrast agent based on an injectable hydrogel nanocomposite containing a lanthanide-activated layered double hydroxide coupled to a biocompatible dye (indocyanine green), emitting in the first biological window.

Resting-state functional magnetic resonance imaging reveals functional connectivity alteration in the experimental autoimmune encephalomyelitis model of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune degenerative disease targeting white matter in the central nervous system. The most common animal model that mimics MS is experimental autoimmune encephalomyelitis (EAE) and it plays a crucial role in pharmacological research, from the identification of a therapeutic target to the in vivo validation of efficacy. Magnetic resonance imaging (MRI) is largely used to detect MS lesions, and resting-state functional MRI (rsfMRI) to investigate alterations in the brain functional connectivity (FC).

Non-lesional white matter in relapsing-remitting multiple sclerosis assessed by multicomponent T2 relaxation.

Introduction: The purpose of the study is to investigate, by T2 relaxation, non-lesional white matter (WM) in relapsing-remitting (RR) multiple sclerosis (MS).

Methods: Twenty stable RR MS patients underwent 1.5T Magnetic Resonance Imaging (MRI) with 3D Fluid-Attenuated Inversion-Recovery (FLAIR), 3D-T1-weighted, and T2-relaxation multi-echo sequences.

Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge.

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMRI Diffusion-Simulated Connectivity (DiSCo) challenge was carried out to evaluate state-of-the-art connectivity methods using novel large-scale numerical phantoms. The diffusion signal for the phantoms was obtained from Monte Carlo simulations.

Age-Related In Vivo Structural Changes in the Male Mouse Olfactory Bulb and Their Correlation with Olfactory-Driven Behavior.

Olfactory areas in mammalian brains are linked to centers that modulate behavior. During aging, sensitivity to odors decreases and structural changes are described in olfactory areas. We explored, in two groups of male mice (young and elderly, 6 and 19 months old, respectively), the link between the changes in olfactory bulb structure, detected with magnetic resonance imaging, and behavioral changes in a battery of tests on motor, olfactory, cognitive performance, and emotional reactivity.

A New Method to Easily Assess Bacteriostatic and Bactericidal Activity of Ultraviolet Radiation Using Quantitative Image Analysis.

Ultraviolet (UV) radiation can elicit both bactericidal and bacteriostatic activity depending on light parameters and targeted bacteria. Current methods based on bacterial growth on solid medium allow measurement of only bactericidal but not bacteriostatic activity, while liquid cultures exhibit low light penetration. Here, we propose a method to quantify both bactericidal and bacteriostatic activity of radiation based on (a) bacterial cultures on solid medium, (b) acquisition and quantitative analysis of photographic images of plates containing bacterial colonies, (c) application of two mathematical equations to evaluate bactericidal and bacteriostatic activity.

Quantitative magnetic resonance characterization of the effect of physical training on skeletal muscle of the Ts65Dn mice, a model of Down syndrome.

Down syndrome (DS) is characterized by muscle hypotonia and low muscle strength associated with motor dysfunction. Elucidation of the determinants of muscle weakness in DS would be relevant for therapeutic approaches aimed at treating/mitigating a physical disability with a strong impact on the quality of life in persons with DS. The Ts65Dn mice is a recognized mouse model of DS, with trisomic mice presenting gross motor and muscle phenotypes.

Tractostorm 2: Optimizing tractography dissection reproducibility with segmentation protocol dissemination.

The segmentation of brain structures is a key component of many neuroimaging studies. Consistent anatomical definitions are crucial to ensure consensus on the position and shape of brain structures, but segmentations are prone to variation in their interpretation and execution. White-matter (WM) pathways are global structures of the brain defined by local landmarks, which leads to anatomical definitions being difficult to convey, learn, or teach.

Multicomponent T relaxometry reveals early myelin white matter changes induced by proton radiation treatment.

Purpose: To investigate MRI myelin water imaging (MWI) by multicomponent T relaxometry as a quantitative imaging biomarker for brain radiation-induced changes and to compare it with DTI.

Methods: Sixteen patients underwent fractionated proton therapy (PT) receiving dose to the healthy tissue because of direct or indirect (base skull tumors) irradiation. MWI was performed by a multi-echo sequence with 32 equally spaced echoes (10-320 ms).

MRI characterization of rat brain aging at structural and functional level: Clues for translational applications.

Magnetic resonance imaging (MRI) paradigms, using non-invasive approaches, can provide relevant findings about brain aging. The attention has been primarily focused on neurodegenerative diseases, while little or nothing has been done to differentiate physiology from pathology. The present study aimed to test diffusion tensor imaging (DTI) and functional MRI (fMRI) metrics to analyze physiological age-related changes in rats at myelin structure and activation level; findings were validated by ex vivo histology.

Quantitative Multicomponent T2 Relaxation Showed Greater Sensitivity Than Flair Imaging to Detect Subtle Alterations at the Periphery of Lower Grade Gliomas.

Purpose: To demonstrate that quantitative multicomponent T2 relaxation can be more sensitive than conventional FLAIR imaging for detecting cerebral tissue abnormalities.

Methods: Six patients affected by lower-grade non-enhancing gliomas underwent T2 relaxation and FLAIR imaging before a radiation treatment by proton therapy (PT) and were examined at follow-up. The T2 decay signal obtained by a thirty-two-echo sequence was decomposed into three main components, attributing to each component a different T2 range: water trapped in the lipid bilayer membrane of myelin, intra/extracellular water and cerebrospinal fluid.

A smaller olfactory bulb in a mouse model of Down syndrome.

Persons with trisomy 21 (Down syndrome) present different phenotypes, including early neurodegeneration, which is prominent in the brain olfactory areas, and olfactory deficit. The use of in vivo techniques in animal models allows to characterize and follow up these slowly developing phenomena. We explored by means of magnetic resonance imaging the olfactory bulb of the Ts65Dn mouse, an established model of Down syndrome, searching for possible syndrome‑related changes.

Default mode network activity in bipolar disorder.

Since its discovery in 1997, the default mode network (DMN) and its components have been extensively studied in both healthy individuals and psychiatric patients. Several studies have investigated possible DMN alterations in specific mental conditions such as bipolar disorder (BD). In this review, we describe current evidence from resting-state functional magnetic resonance imaging studies with the aim to understand possible changes in the functioning of the DMN in BD.

ASC-Exosomes Ameliorate the Disease Progression in SOD1(G93A) Murine Model Underlining Their Potential Therapeutic Use in Human ALS.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motoneurons. To date, there is no effective treatment available. Exosomes are extracellular vesicles that play important roles in intercellular communication, recapitulating the effect of origin cells.

Slow versus fast rewarming after hypothermic circulatory arrest: effects on neuroinflammation and cerebral oedema.

Objectives: Among the factors that could determine neurological outcome after hypothermic circulatory arrest (HCA) rewarming is rarely considered. The optimal rewarming rate is still unknown. The goal of this study was to investigate the effects of 2 different protocols for rewarming after HCA on neurological outcome in an experimental animal model.

Resting state networks activity in euthymic bipolar disorder.

Objectives: Bipolar disorder (BD) is a psychiatric condition causing shifts in mood, energy and activity levels severely altering the quality of life of the patients even in the euthymic phase. Although widely accepted, the neurobiological bases of the disorder in the euthymic phase remain elusive. This study aims at characterizing resting state functional activity of the BD euthymic phase in order to better understand the pathogenesis of the disease and build future neurobiological models.

The motor cortex of the sheep: laminar organization, projections and diffusion tensor imaging of the intracranial pyramidal and extrapyramidal tracts.

The laminar organization of the motor cortex of the sheep and other large domestic herbivores received scarce attention and is generally considered homologous to that of rodents and primates. Thickness of the cortex, subdivision into layers and organization are scarcely known. In the present study, we applied different modern morphological, mathematical and image-analyses techniques to the study of the motor area that controls movements of the forelimb in the sheep.

Heterogeneous Enhancement Pattern in DCE-MRI Reveals the Morphology of Normal Lymph Nodes: An Experimental Study.

Purpose: To investigate the heterogeneous enhancement pattern in normal lymph nodes of healthy mice by different albumin-binding contrast agents.

Methods: The enhancement of normal lymph nodes was assessed in mice by dynamic contrast-enhanced MRI (DCE-MRI) after the administration of two contrast agents characterized by different albumin-binding properties: gadopentetate dimeglumine (Gd-DTPA) and gadobenate dimeglumine (Gd-BOPTA). To take into account potential heterogeneities of the contrast uptake in the lymph nodes, k-means cluster analysis was performed on DCE-MRI data.

Easy formulation of liposomal doxorubicin modified with a bombesin peptide analogue for selective targeting of GRP receptors overexpressed by cancer cells.

The article concerns the obtainment of liposomal doxorubicin (Dox) in which liposomes are externally modified with a targeting peptide able to drive the formulation in a selective way on membrane receptors overexpressed in tumors. We developed a kit composed by three different vials: (A) a vial containing a sterile, translucent, red dispersion of the liposomal doxorubicin drug (Doxil®), (B) a vial filled with a lyophilized powder of a modified phospholipid with a reactive function (DSPE-Peg-maleimide), and (C) a vial containing a 1-9 bombesin peptide analogue (Cys-BN-AA1) chemically modified to react in stoichiometric ratio respect to DSPE-Peg-maleimide. The chosen peptide is a stable analogue antagonist of the wild-type 1-9 bombesin peptide; it is very stable in serum; maintains high specificity, with nanomolar affinity, towards gastrin release peptide receptors (GRPRs indicated also as BB2); and is overexpressed in some cancer cells.

Central nervous system microbleeds in the acute phase are associated with structural integrity by DTI one year after mild traumatic brain injury: A longitudinal study.

Introduction: Several imaging modalities are under investigation to unravel the pathophysiological mystery of delayed performance deficits in patients after mild traumatic brain injury (mTBI). Although both imaging and neuropsychological studies have been conducted, only few data on longitudinal correlations of diffusion tensor imaging (DTI), susceptibility weighted imaging (SWI) and extensive neuropsychological testing exist.

Methods: MRI with T1- and T2-weighted, SWI and DTI sequences at baseline and 12 months of 30 mTBI patients were compared with 20 healthy controls.

A SERRS/MRI multimodal contrast agent based on naked Au nanoparticles functionalized with a Gd(iii) loaded PEG polymer for tumor imaging and localized hyperthermia.

Multimodal contrast agents offer new interesting diagnostic possibilities, summing the benefits of multiple imaging techniques. Magnetic resonance and optical imaging are complementary techniques. The first allows total body screening, even though it suffers from low spatial resolution and needs high loadings, whereas the second shows lower penetration, but bright signals, and a higher spatial resolution and needs lower loadings.

Labeling and Magnetic Resonance Imaging of Exosomes Isolated from Adipose Stem Cells.

Adipose stem cells (ASC) represent a promising therapeutic approach for neurodegenerative diseases. Most biological effects of ASC are probably mediated by extracellular vesicles, such as exosomes, which influence the surrounding cells. Current development of exosome therapies requires efficient and noninvasive methods to localize, monitor, and track the exosomes.

MRI reveals therapeutical efficacy of stem cells: An experimental study on the SOD1(G93A) animal model.

Purpose: The first part of the experiment identifies and validates MRI biomarkers distinctive of the disease progression in the transgenic superoxide dismutase gene (SOD1(G93A)) animal model. The second part assesses the efficacy of a mesenchymal stem cell-based therapy through the MRI biomarkers previously defined.

Methods: The first part identifies MRI differences between SOD1(G93A) and healthy mice.