A5048962461- Advanced MRI Techniques and Applications
- Advanced Neuroimaging Techniques and Applications
- Functional Brain Connectivity Studies
- Neuroscience and Neuropharmacology Research
- MRI in cancer diagnosis
- Lanthanide and Transition Metal Complexes
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Neural dynamics and brain function
- Cardiac electrophysiology and arrhythmias
- Electron Spin Resonance Studies
- Mitochondrial Function and Pathology
- Trace Elements in Health
- NMR spectroscopy and applications
- Nanoparticle-Based Drug Delivery
- Characterization and Applications of Magnetic Nanoparticles
- Cardiac Imaging and Diagnostics
- Optical Imaging and Spectroscopy Techniques
- Neurogenesis and neuroplasticity mechanisms
- Cardiomyopathy and Myosin Studies
- Neuroinflammation and Neurodegeneration Mechanisms
- Olfactory and Sensory Function Studies
- Ion channel regulation and function
- Metabolism and Genetic Disorders
- Medical Imaging Techniques and Applications
National Institute of Neurological Disorders and Stroke
2016-2025
National Institutes of Health
2016-2025
Emory University
2025
Oxford University Press (United Kingdom)
2020
Repatriation General Hospital
2015
The University of Melbourne
2015
Lawrence Berkeley National Laboratory
1983-2015
National Institute of Standards and Technology
2011
Institute of Molecular Functional Materials
2009
Yale University
2008
A technique has been developed for proton magnetic resonance imaging (MRI) of perfusion, using water as a freely diffusable tracer, and its application to the measurement cerebral blood flow (CBF) in rat is demonstrated. The method involves labeling inflowing spins arterial by inverting them continuously at neck region observing effects inversion on intensity brain MRI. Solution Bloch equations, modified include flow, allows regional perfusion rates be measured from an image with spin...
Abstract Measurement of tissue perfusion is important for the functional assessment organs in vivo. Here we report use 1 H NMR imaging to generate maps rat brain at 4.7 T. Blood water flowing saturated neck region with a sliceselective saturation sequence, creating an endogenous tracer form proximally spins. Because proton T times are relatively long, particularly high field strengths, spins exchange bulk and steady state created where regional concentration determined by blood flow . Distal...
Abstract The failing human heart expresses tumor necrosis factor-α (TNF-α). However, its pathophysiological significance is not clear. We previously reported that robust overexpression of TNF-α in the murine causes lethal myocarditis. In this study, we modified transgene to reduce production by preserving destabilizing sequence cDNA. Expression was driven α-myosin heavy chain promoter. Use construct allowed us establish a transgenic line (TG). TG offspring were examined at 6, 12, and 24...
The ability to detect brain anatomy and pathophysiology with MRI is limited by the contrast-to-noise ratio (CNR), which depends on contrast mechanism used spatial resolution. In this work, we show that in of human brain, large improvements noise high-resolution images are possible exploiting signal phase at high magnetic field strength. Using gradient-echo 7.0 tesla a multichannel detector, nominal voxel size 0.24 × 1.0 mm 3 (58 nl) was achieved. At resolution, strong observed both between...
To investigate the role of an activated K-Ras gene in initiation and maintenance lung adenocarcinomas, we developed transgenic mice that express murine K-Ras4b G12D under control doxycycline type II pneumocytes. Focal proliferative lesions alveolar pneumocytes were observed as early seven days after induction with doxycycline; two months induction, lungs contained adenomas focal invasion pleura at later stages. Removal caused a rapid fall levels mutant RNA concomitant apoptotic regression...
There is rapid growth in the use of MRI for molecular and cellular imaging. Much this work relies on high relaxivity nanometer-sized, ultrasmall dextran-coated iron oxide particles. Typically, millions particles must be loaded into cells efficient detection. Here we show that single, micrometer-sized (MPIOs) can detected by vitro agarose samples, cultured cells, mouse embryos. Experiments studying effects resolution particle size from 0.76 to 1.63 microm indicated T(2)* readily single MPIOs...
Abstract Present techniques for functional MRI rely on detecting changes in hemodynamics that result as a consequence of brain activation. It would be useful if could developed enable imaging parameter directly related to neuronal activity. Influx calcium into neurons is necessary release neurotransmitters. Divalent manganese ions (Mn 2+ ) can enter cells through voltage‐gated channels and Mn paramagnetic. accumulation due activation should alter relaxation times offering an approach...
Abstract Development of efficient imaging techniques to trace neuro nal connections would be very useful. Manganese ion (Mn 2+ ) is an excellent T 1 contrast agent for magnetic resonance (MRI). Four reports utilizing radioactive Mn in fish and rat brain indicate that may useful tracing neuronal connections. Therefore, the purpose this work was determine if can used as vivo MRI tract tracer. The results topical admin istration MnCI 2 solution naris mice well retinal ganglion cells via...
Abstract The use of high‐relaxivity, intracellular contrast agents has enabled MRI monitoring cell migration through and homing to various tissues, such as brain, spinal cord, heart, muscle. Here it is shown that can detect single cells in vivo, tissue, following labeling transplantation. Primary mouse hepatocytes were double‐labeled with green fluorescent 1.63‐μm iron oxide particles red endosomal dye, injected into the spleens recipient mice. This a common hepatocyte transplantation...
Background Commercial low-field-strength MRI systems are generally not equipped with state-of-the-art hardware, and suitable for demanding imaging techniques. An system was developed that combines low field strength (0.55 T) high-performance technology. Purpose To evaluate applications of a system, specifically MRI-guided cardiovascular catheterizations metallic devices, diagnostic in high-susceptibility regions, efficient image acquisition strategies. Materials Methods A commercial 1.5-T...
Abstract There is rapidly increasing interest in the use of MRI to track cell migration intact animals. Currently, labeling usually accomplished by endocytosis nanometer‐sized, dextran‐coated iron oxide particles. The limitations using nanometer‐sized particles, however, are that millions particles required achieve sufficient contrast, label can be diluted beyond observability division, and biodegradable. These problems make it difficult cells other than macrophages vivo, conduct long‐term...
The blood oxygenation level-dependent (BOLD) response to somatosensory stimulation was measured in α-chloralose-anesthetized rats. BOLD fMRI obtained at 40-ms temporal resolution and spatial of 200 × 2,000 μm 3 by using a gated activation paradigm an 11.7 T MRI. Results show consistent heterogeneity onset times amplitudes. earliest time (0.59 ± 0.17 s, n = 9) corresponded anatomically layer IV, with superficial deeper layers starting significantly later (1.27 0.43 s I–III, 1.11 0.45 VI)....
Cyclosporin A sensitive swelling of mitochondria isolated from control mouse livers and the transgenic mice expressing human ubiquitous mitochondrial creatine kinase occurred in presence both 40 μM calcium 5 atractyloside which was accompanied by a 2.5‐fold increase over state 4 respiration rates. Creatine cyclocreatine inhibited latter only liver mitochondria. Protein complexes detergent solubilised rat brain extracts, containing octameric kinase, porin adenine nucleotide translocator, were...
The spatiotemporal evolution of cerebral microcirculatory adjustments to functional brain stimulation is the fundamental determinant specificity hemodynamically weighted neuroimaging signals. Very little data, however, exist on reactivity capillaries, vessels most proximal activated neuronal population. Here, we used two-photon laser scanning microscopy, in combination with intracranial electrophysiology and intravital video explore changes cortical hemodynamics, at level individual response...
Experiments were designed to evaluate the relative contribution of impulse propagation failure, high-energy phosphate depletion, lowered pH, and impaired excitation-contraction coupling human muscle fatigue recovery. 31P nuclear magnetic resonance spectroscopy measurements made on adductor pollicis muscle, together with simultaneous M-wave, force, rectified integrated EMG (RIEMG). During fatigue, maximum voluntary contraction force (MVC) fell by 90%, pH from 7.1 6.4, phosphocreatine was...