mapping of the chemical exchange relayed nuclear Overhauser effect using deep magnetic resonance fingerprinting.

Noninvasive magnetic resonance imaging (MRI) of the relayed nuclear Overhauser effect (rNOE) constitutes a promising approach for gaining biological insights into various pathologies, including brain cancer, kidney injury, ischemic stroke, and liver disease. However, rNOE imaging is time-consuming and prone to biases stemming from the water T1 and the semisolid magnetization transfer (MT) contrasts. Here, we developed a rapid rNOE quantification approach, combining magnetic resonance fingerprinting (MRF) acquisition with deep-learning-based reconstruction.

Detection of 10 commonly used pharmaceuticals in reef-building stony corals from shallow (5-12 m) and deep (30-40 m) sites in the Red Sea.

Although pharmaceutically-active compounds (PhACs) are increasingly being found to be present in marine environments, their presence in coral reefs, already under threat from various stressors, has remains unexplored. This study focused on PhAC presence in two stony-coral genera, collected from different depths and sites in the Red Sea. The findings reveal the presence of ten different PhACs, with elevated concentrations detected in corals from shallow sites and in areas with heavy human activity.

Effect of reducing isoflurane level on glucosamine uptake in the mouse brain during magnetic resonance imaging studies.

Anesthesia is often required during magnetic resonance imaging (MRI) examinations in animal studies. Anesthetic drugs differ in their capacity to interfere with homeostatic mechanisms responsible for glucose metabolism in the brain, which may create a constraint in the study design. Recent studies suggest that the chemical exchange saturation transfer (CEST) MRI scanning technique can detect localized metabolic changes in rodent brains induced by the uptake of glucose or its analogs; however, most of these studies do not account for the impact of anesthesia type on the brain metabolism.

Metabolic brain imaging with glucosamine CEST MRI: in vivo characterization and first insights.

The utility of chemical exchange saturation transfer (CEST) MRI for monitoring the uptake of glucosamine (GlcN), a safe dietary supplement, has been previously demonstrated in detecting breast cancer in both murine and human subjects. Here, we studied and characterized the detectability of GlcN uptake and metabolism in the brain. Following intravenous GlcN administration in mice, CEST brain signals calculated by magnetization transfer ratio asymmetry (MTRasym) analysis, were significantly elevated, mainly in the cortex, hippocampus, and thalamus.

Phosphate buffer-catalyzed kinetics of mutarotation of glucosamine investigated by NMR spectroscopy.

Glucosamine (2-amino-2-deoxy-d-glucose, GlcN) is a naturally occurring amino monosaccharide that is essential for a variety of biological functions, it is mainly involved in the formation of polysaccharide structures. It was recently reported to enable the imaging of cancerous tumors as an exogenous contrast agent using the MRI technique of chemical exchange saturation transfer (CEST). In preparation for the clinical use of GlcN, its anomeric equilibrium and mutarotation rate constants were directly investigated in this study utilizing high resolution H and C NMR spectroscopy.

Quantitative Magnetization EXchange MRI Measurement of Liver Fibrosis Model in Rodents.

Background: Quantitative MRI can elucidate the complex microstructural changes in liver disease. The Magnetization EXchange (MEX) method estimates macromolecular fraction, such as collagen, and can potentially aid in this task.

Hypothesis: MEX sequence, and its derived quantitative macromolecular fraction, should correlate with collagen deposition in rodents liver fibrosis model.

Breast cancer imaging with glucosamine CEST (chemical exchange saturation transfer) MRI: first human experience.

Objectives: This study aims to evaluate the feasibility of imaging breast cancer with glucosamine (GlcN) chemical exchange saturation transfer (CEST) MRI technique to distinguish between tumor and surrounding tissue, compared to the conventional MRI method.

Methods: Twelve patients with newly diagnosed breast tumors (median age, 53 years) were recruited in this prospective IRB-approved study, between August 2019 and March 2020. Informed consent was obtained from all patients.

An in vivo implementation of the MEX MRI for myelin fraction of mice brain.

Objective: Magnetization EXchange (MEX) sequence measures a signal linearly dependent on the myelin proton fraction by selective suppression of water magnetization and a recovery period. Varying the recovery period enables extraction of the percentile fraction of myelin bound protons. We aim to demonstrate the MEX sequence sensitivity to the fraction of protons associated with myelin in mice brain, in vivo.

Deuterium double quantum-filtered NMR studies of peripheral and optic nerves.

Objective: Characterization of the nerve components by deuterium double quantum-filtered magnetization transfer (DQF-MT) NMR.

Methods: Nerves were equilibrated in deuterated saline and H single-pulse and H DQF-MT NMR spectra were measured, enabling the separation of the different water compartments, according to their quadrupolar splittings.

Results: Rat sciatic and brachial nerves and porcine optic nerve immersed in deuterated saline yielded H DQF spectra composed of three pairs of quadrupolar-split signals assigned to the water in the collagenous compartments and the myelin bilayer and one narrow signal assigned to the axonal water.

Proteomic changes in the solitary ascidian Herdmania momus following exposure to the anticonvulsant medication carbamazepine.

The increasing use of pharmaceuticals in human and veterinary medicine, along with their poor removal rates at wastewater treatment facilities is resulting in the chronic release of pharmaceutically-active compounds (PhACs) into the marine environment, where they pose a threat to non-target organisms. A useful approach, as applied in the current study for assessing the effects of PhACs on non-target organisms, is the proteomic approach: the large-scale study of an organism's proteins. Using 'shotgun' proteomics, we identified differentially-expressed proteins based on peptide fragments in the solitary ascidian, Herdmania momus, following a 14-day laboratory experimental exposure to the PhAC carbamazepine (CBZ), an anticonvulsant and antidepressant medication, frequently detected in the aquatic environment.

Identification of water compartments in spinal cords by H double quantum filtered NMR.

In H double quantum filtered (DQF) NMR, the various water compartments are characterized by their different residual quadrupolar interactions. The spectral separation between the different signals enables the measurement of the relaxation of each compartment and the magnetization transfer (MT) between them. In the current study, five water compartments were identified in the H DQF spectra of porcine spinal cord.

Molecular imaging of cancer by glucosamine chemical exchange saturation transfer MRI: A preclinical study.

Glucosamine (GlcN) was recently proposed as an agent with an excellent safety profile to detect cancer with the chemical exchange saturation transfer (CEST) MRI technique. Translation of the GlcN CEST method to the clinical application requires evaluation of its sensitivity to the different frequency regions of irradiation. Hence, imaging of the GlcN signal was established for the full Z spectra recorded following GlcN administration to mice bearing implanted 4T1 breast tumors.

Consciously monitored grasping is vulnerable to perceptual intrusions.

The idea of functional differentiation between vision-for-action and vision-for-perception has been supported by evidence from different domains. According to this account, perception is based on consciously accessible, relative representations, whereas vision-for-action is performed in an analytic, automatic manner. Support for this idea comes from studies that showed that unlike perception, grasping movements are refractory to illusions and to Weber's law.

Assessing pharmaceutical contamination along the Mediterranean and Red Sea coasts of Israel: Ascidians (Chordata, Ascidiacea) as bioindicators.

Global increase in the use of pharmaceutically-active compounds (PhACs), and their insufficient removal in wastewater treatment plants, have resulted in their continuous release into the marine environment. We investigated the use of the solitary ascidians Herdmania momus, Microcosmus exasperatus, and Styela plicata as bioindicators of three common PhACs in the Israeli coastal waters: Bezafibrate, carbamazepine and diclofenac. Both the Mediterranean and the Red-Sea coasts were found contaminated with PhACs, detected at all 11 sampling sites, with four sites contaminated with all three studied PhACs.

New insight into the organization of myelin water using deuterium NMR.

Purpose: Myelin water is commonly characterized by its short proton T relaxation time, suggesting strong association with the polar head groups of the bilayer constituents. Deuterium NMR of water in ordered structures exhibits splittings as a result of quadrupolar interactions that are observable using the double-quantum filter. The purpose of the current study was to identify and characterize the water populations.

Molecular imaging of tumors by chemical exchange saturation transfer MRI of glucose analogs.

Early detection of the cancerous process would benefit greatly from imaging at the cellular and molecular level. Increased glucose demand has been recognized as one of the hallmarks of cancerous cells (the "Warburg effect"), hence glucose and its analogs are commonly used for cancer imaging. One example is FDG-PET technique, that led to the use of chemical exchange saturation transfer (CEST) MRI of glucose ("glucoCEST") for tumor imaging.

Quantification of hydroxyl exchange of D-Glucose at physiological conditions for optimization of glucoCEST MRI at 3, 7 and 9.4 Tesla.

Aims: To determine individual glucose hydroxyl exchange rates at physiological conditions and use this information for numerical optimization of glucoCEST/CESL preparation. To give guidelines for in vivo glucoCEST/CESL measurement parameters at clinical and ultra-high field strengths.

Methods: Five glucose solution samples at different pH values were measured at 14.

3-O-Methyl-D-glucose mutarotation and proton exchange rates assessed by C, H NMR and by chemical exchange saturation transfer and spin lock measurements.

3-O-Methyl-D-glucose (3OMG) was recently suggested as an agent to image tumors using chemical exchange saturation transfer (CEST) MRI. To characterize the properties of 3OMG in solution, the anomeric equilibrium and the mutarotation rates of 3OMG were studied by H and C NMR. This information is essential in designing the in vivo CEST experiments.

The role of magnetization transfer in the observed contrast in T weighted imaging under clinical setups.

In T weighted magnetic resonance imaging of brain and spinal cord in the clinical setting, the white matter (WM) appears with greater intensity than the gray matter (GM). This contrast has been assigned to differences in T values. In these experiments the RF pulses are too long to excite both the water and the species with restricted motion of the protons (SRMP).

CEST MRI of 3-O-methyl-D-glucose on different breast cancer models.

Purpose: To test the ability of chemical exchange saturation transfer (CEST) MRI of 3-O-methyl-D-glucose (3OMG) to detect tumors in several breast cancer models of murine and human origin, for different routes of administration of the agent and to compare the method with glucoCEST and with FDG-PET on the same animals.

Methods: In vivo CEST MRI experiments were performed with a 7T Biospec animal MRI scanner on implanted orthotopic mammary tumors of mice before and after administration of 3OMG.

Results: A marked 3OMG-CEST MRI contrast that was correlated with the administrated dose was obtained in different breast cancer models and by intravenous, intraperitoneal, and per os methods of administration.

Teriparatide attenuates scarring around murine cranial bone allograft via modulation of angiogenesis.

Nearly all bone fractures in humans can deteriorate into a non-union fracture, often due to formation of fibrotic tissue. Cranial allogeneic bone grafts present a striking example: although seemingly attractive for craniofacial reconstructions, they often fail due to fibrosis at the host-graft junction, which physically prevents the desired bridging of bone between the host and graft and revitalization of the latter. In the present study we show that intermittent treatment with recombinant parathyroid hormone-analogue (teriparatide) modulates neovascularization feeding in the graft surroundings, consequently reducing fibrosis and scar tissue formation and facilitates osteogenesis.

Glucosamine and N-acetyl glucosamine as new CEST MRI agents for molecular imaging of tumors.

The efficacy of glucosamine (GlcN) and N-acetyl glucosamine (GlcNAc) as agents for chemical exchange saturation transfer (CEST) magnetic resonance molecular imaging of tumors is demonstrated. Both agents reflect the metabolic activity and malignancy of the tumors. The method was tested in two types of tumors implanted orthotopically in mice: 4T1 (mouse mammary cancer cells) and MCF7 (human mammary cancer cells).

Hyperpolarized (6)Li as a probe for hemoglobin oxygenation level.

Hyperpolarization by dissolution dynamic nuclear polarization (DNP) is a versatile technique to dramatically enhance the nuclear magnetic resonance (NMR) signal intensity of insensitive long-T1 nuclear spins such as (6)Li. The (6)Li longitudinal relaxation of lithium ions in aqueous solutions strongly depends on the concentration of paramagnetic species, even if they are present in minute amounts. We herein demonstrate that blood oxygenation can be readily detected by taking advantage of the (6)Li signal enhancement provided by dissolution DNP, together with the more than 10% decrease in (6)Li longitudinal relaxation as a consequence of the presence of paramagnetic deoxyhemoglobin.

Sodium NMR/MRI for anisotropic systems.

Sodium ((23)Na) plays a central role in many physiological processes, and its high NMR sensitivity makes it an attractive nucleus for biomedical NMR and MRI research. Many biological tissues contain structures such as fibers and membranes that impose anisotropic translational and rotational motions on the sodium ions. Translational motion can be studied by diffusion measurements.