Preserved Edge Convolutional Neural Network for Sensitivity Enhancement of Deuterium Metabolic Imaging (DMI).

Purpose: Common to most MRSI techniques, the spatial resolution and the minimal scan duration of Deuterium Metabolic Imaging (DMI) are limited by the achievable SNR. This work presents a deep learning method for sensitivity enhancement of DMI.

Methods: A convolutional neural network (CNN) was designed to estimate the 2H-labeled metabolite concentrations from low SNR and distorted DMI FIDs.

Mapping of exogenous choline uptake and metabolism in rat glioblastoma using deuterium metabolic imaging (DMI).

Introduction: There is a lack of robust metabolic imaging techniques that can be routinely applied to characterize lesions in patients with brain tumors. Here we explore in an animal model of glioblastoma the feasibility to detect uptake and metabolism of deuterated choline and describe the tumor-to-brain image contrast.

Methods: RG2 cells were incubated with choline and the level of intracellular choline and its metabolites measured in cell extracts using high resolution H NMR.

Preclinical evaluation of a brain penetrant PARP PET imaging probe in rat glioblastoma and nonhuman primates.

Purpose: Currently, there are multiple active clinical trials involving poly(ADP-ribose) polymerase (PARP) inhibitors in the treatment of glioblastoma. The noninvasive quantification of baseline PARP expression using positron emission tomography (PET) may provide prognostic information and lead to more precise treatment. Due to the lack of brain-penetrant PARP imaging agents, the reliable and accurate in vivo quantification of PARP in the brain remains elusive.

NMR visibility of deuterium-labeled liver glycogen in vivo.

Purpose: Deuterium metabolic imaging (DMI) combined with [6,6'- H ]-glucose has the potential to detect glycogen synthesis in the liver. However, the similar chemical shifts of [6,6'- H ]-glucose and [6,6'- H ]-glycogen in the H NMR spectrum make unambiguous detection and separation difficult in vivo, in contrast to comparable approaches using C MRS. Here the NMR visibility of H-labeled glycogen is investigated to better understand its potential contribution to the observed signal in liver following administration of [6,6'- H ]-glucose.

Characterization of Kinetic Isotope Effects and Label Loss in Deuterium-Based Isotopic Labeling Studies.

Deuterium metabolic imaging (DMI) is a novel, 3D, magnetic resonance (MR)-based method to map metabolism of deuterated substrates . The replacement of protons with deuterons could potentially lead to kinetic isotope effects (KIEs) in which metabolic rates of deuterated substrates are reduced due to the presence of a heavier isotope. Knowledge of the extent of KIE and H label loss due to exchange reactions is required for DMI-based measurements of absolute metabolic rates.

Triadin/Junctin double null mouse reveals a differential role for Triadin and Junctin in anchoring CASQ to the jSR and regulating Ca(2+) homeostasis.

Triadin (Tdn) and Junctin (Jct) are structurally related transmembrane proteins thought to be key mediators of structural and functional interactions between calsequestrin (CASQ) and ryanodine receptor (RyRs) at the junctional sarcoplasmic reticulum (jSR). However, the specific contribution of each protein to the jSR architecture and to excitation-contraction (e-c) coupling has not been fully established. Here, using mouse models lacking either Tdn (Tdn-null), Jct (Jct-null) or both (Tdn/Jct-null), we identify Tdn as the main component of periodically located anchors connecting CASQ to the RyR-bearing jSR membrane.

¹H-[¹³C]-nuclear magnetic resonance spectroscopy measures of ketamine's effect on amino acid neurotransmitter metabolism.

Ketamine has recently gained significant attention owing to its psychotomimetic and more recently discovered rapid antidepressant-like properties. ¹H-[¹³C]-nuclear magnetic resonance studies were employed to explore potential physiological processes underlying these unique effects. [1-¹³C]glucose and [2-¹³C]acetate-nuclear magnetic resonance ex vivo studies were performed on the medial prefrontal cortex (mPFC) and hippocampus of rats acutely treated with 30 mg/kg or 80 mg/kg ketamine and compared with saline-treated animals to determine the effects of ketamine on amino acid neurotransmitter cycling and glial metabolism.

Meiotic transmission of epigenetic changes in the cell-division factor requirement of plant cells.

During the development of tobacco plants, cells undergo epigenetic changes that alter their requirement in culture for the cell-division factor cytokinin. Cultured leaf cells alternate between cytokinin-requiring (C-) and cytokinin-independent (C+) states at extremely high rates of approximately 10-2 per cell generation by a process called pseudodirected variation. Here we show that plants regenerated from most C+ clones express the Habituated leaf (Hl) trait, i.