Comparison of potassium and sodium binding in vivo and in agarose samples using TQTPPI pulse sequence.

Potassium and sodium specific binding in vivo were explored at 21.1T by triple quantum (TQ) magnetic resonance (MR) signals without filtration to achieve high sensitivities and precise quantifications. The pulse sequence used time proportional phase increments (TPPI).

MRI and MRS of the human brain at magnetic fields of 14T to 20T: Technical feasibility, safety, and neuroscience horizons.

The three goals of this paper are: 1) to evaluate the improvements in technology for increasing magnetic flux density (magnetic field) to 14T in the next few years and eventually to 20T; 2) to highlight neuroscience opportunities enabled by these advances; and, 3) to evaluate the physiological and biophysical effects associated with MRI at very high performance levels. Substantial recent advances in magnet technology including superconductor developments enable neuroscience goals that are not obtainable at contemporary magnetic fields. Ten areas of brain neuroscience include potential improvements in resolution for functional MRI(BOLD), diffusion weighted MRI, tractography, susceptibility weighted MR, neuronal architecture patterns related to human behavior, proton spectroscopy of small brain biochemicals, chemical exchange saturation transfer (CEST), dynamic contrast enhanced MRI, brain energy metabolism using C, O, and P; and brain electrolyte physiology using Na, Cl, and K.

Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale.

An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to 20 T has been underway since 2012. This initiative has been supported by 22 interested participants from the USA and Europe, of which 15 are authors of this review. Advances in high temperature superconductor materials, advances in cryocooling engineering, prospects for non-persistent mode stable magnets, and experiences gained from large-bore, high-field magnet engineering for the nuclear fusion endeavors support the feasibility of a human brain MRI and MRS system with 1 ppm homogeneity over at least a 16-cm diameter volume and a bore size of 68 cm.

Measurement of brachial artery endothelial function using a standard blood pressure cuff.

The integrity of endothelial function in major arteries (EFMA) is a powerful independent predictor of heart attack and stroke. Existing ultrasound-based non-invasive assessment methods are technically challenging and suitable only for laboratory settings. EFMA, like blood pressure (BP), is both acutely and chronically affected by factors such as lifestyle and medication.

Imaging and modeling of flow in porous media using clinical nuclear emission tomography systems and computational fluid dynamics.

This paper presents experimental and modeling aspects of applying nuclear emission tomography to study fluid flow in laboratory packed porous media columns of the type frequently used in geophysics, geochemistry and hydrology research. Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are used as non-invasive tools to obtain dynamic 3D images of radioactive tracer concentrations. Dynamic sequences obtained using F-FDG PET are used to trace flow through a 5 cm diameter × 20 cm tall sand packed column with and without an impermeable obstacle.

Dynamic single photon emission computed tomography--basic principles and cardiac applications.

The very nature of nuclear medicine, the visual representation of injected radiopharmaceuticals, implies imaging of dynamic processes such as the uptake and wash-out of radiotracers from body organs. For years, nuclear medicine has been touted as the modality of choice for evaluating function in health and disease. This evaluation is greatly enhanced using single photon emission computed tomography (SPECT), which permits three-dimensional (3D) visualization of tracer distributions in the body.

Assessment of endothelial function in the radial artery using inhaled albuterol.

Endothelial dysfunction is an early indicator of developing atherosclerosis and is a strong predictor of future heart attack and stroke. At present, evaluation of endothelial function (EF) (specifically, EF mediated by nitric oxide, NO) is too technically difficult to form part of a routine clinical examination. Non-invasive methods that measure NO-dependent EF in arteries make use of a 4-5 minute blood pressure cuff occlusion of the arm in order to induce reactive hyperemia (RH) upon cuff release.

ZigBee-based wireless intra-oral control system for quadriplegic patients.

A human-to-computer system that includes a wireless intra-oral module, a wireless coordinator and distributed wireless controllers, is presented. The state-of-the-art ZigBee protocol is employed to achieve reliable, low-power and cost-efficient wireless communication between the tongue, computer and controllers. By manipulating five buttons on the wireless intra-oral module using the tongue, the subject can control cursors, computer menus, wheelchair, lights, TV, phone and robotic devices.

Synthetic nano-LDL with paclitaxel oleate as a targeted drug delivery vehicle for glioblastoma multiforme.

The low density lipoprotein (LDL) receptor has been shown to be upregulated in GBM tumor cells in vitro and is therefore a potential molecular target for the delivery of therapeutic agents. A synthetic nano-LDL (nLDL) particle was developed as a drug delivery vehicle targeted to GBM cells by incorporating a lipophilic prodrug, paclitaxel oleate, into the particle. Nano-LDL containing paclitaxel oleate (nLDL-PO) was constructed by combining a synthetic peptide containing a lipid binding motif and the LDL receptor (LDLR) binding domain of apolipoprotein B-100 with a lipid emulsion consisting of phosphatidyl choline, triolein, and paclitaxel oleate.

Synthetic nano-low density lipoprotein as targeted drug delivery vehicle for glioblastoma multiforme.

The low density lipoprotein (LDL) receptor has been shown to be upregulated in GBM tumor cells and is therefore a potential molecular target for the delivery of therapeutic agents. A synthetic nano-LDL (nLDL) particle was developed and tested to determine its utility as a drug delivery vehicle targeted to GBM tumors. nLDL particles were constructed by combining a synthetic peptide containing a lipid binding motif and the LDL receptor (LDLR) binding domain of apolipoprotein B-100 with a lipid emulsion consisting of phosphatidyl choline, triolein, and cholesteryl oleate.

Evaluation of arterial endothelial function using transit times of artificially induced pulses.

Impairment of arterial endothelial function is an early event in atherosclerosis and correlates with the major risk factors for cardiovascular disease. The most widely employed non-invasive measure of endothelial function involves brachial artery (BA) diameter measurement using ultrasound imaging before and after several minutes of blood flow occlusion. The change in arterial diameter is a measure of flow-mediated vasorelaxation (FMVR).

High-resolution NMR of static samples by rotation of the magnetic field.

Mechanical rotation of a sample at 54.7 degrees with respect to the static magnetic field, so-called magic-angle spinning (MAS), is currently a routine procedure in nuclear magnetic resonance (NMR). The technique enhances the spectral resolution by averaging away anisotropic spin interactions thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings.

Enhanced cutaneous vascular response in AD subjects under donepezil therapy.

Objective: Abnormal cutaneous vasodilatory responses to the iontophoresis of vasodilators were previously observed in Alzheimer's disease (AD). We sought to replicate these observations and further identify peripheral vascular components of AD pathology.

Methods: Methacholine chloride (MCh), acetylcholine chloride (ACh), and sodium nitroprusside (SNP) were applied iontophoretically to forearm skin.

Biomonitoring with wireless communications.

Wireless biomonitoring, first used in human beings for fetal heart-rate monitoring more than 30 years ago, has now become a technology for remote sensing of patients' activity, blood pulse pressure, oxygen saturation, internal pressures, orthopedic device loading, and gastrointestinal endoscopy. Technical advances in miniaturization and wireless communications have enabled development of monitoring devices that can be made available for general use by individuals/patients and caregivers. New methods for short-range wireless communications not encumbered by radio spectrum restrictions (e.

Progenitor endothelial cell involvement in Alzheimer's disease.

There is compelling evidence that endothelial cells of the brain and periphery are dysfunctional in Alzheimer's disease. There is evidence for a fundamental defect in, or abnormal aging of, endothelial progenitor cells in atherosclerosis. The possibility that endothelial cell defects are a primary cause for Alzheimer's disease or other dementias can be researched by molecular and cell biology studies as well as cell trafficking studies using recently demonstrated molecular imaging methods.

Cardiovascular metabolic imaging: physiologic and biochemical dynamics in vivo.

Fifty-eight investigators from the fields of biochemistry, physiology, cardiology, nuclear medicine, and physics met to discuss the development of metabolic imaging techniques for application to cardiovascular and pulmonary studies in health and disease. The workshop was sponsored by the Division of Heart and Vascular Diseases, National Heart, Lung, and Blood Institute and was held on September 16 to 18 in Bethesda, Maryland, in facilities provided by the American College of Cardiology. This report summarizes the presentations and discussions and presents recommendations for future studies.