Collective Correlations of Brodmann Areas fMRI Study with RMT-Denoising

We study collective behavior of Brodmann regions of human cerebral cortex using functional Magnetic Resonance Imaging (fMRI) and Random Matrix Theory (RMT). The raw fMRI data is mapped onto the cortex regions corresponding to the Brodmann areas with the aid of the Talairach coordinates. Principal Component Analysis (PCA) of the Pearson correlation matrix for 41 different Brodmann regions is carried out to determine their collective activity in the idle state and in the active state stimulated by tapping. The collective brain activity is identified through the statistical analysis of the eigenvectors to the largest eigenvalues of the Pearson correlation matrix. The leading eigenvectors have a large participation ratio. This indicates that several Broadmann regions collectively give rise to the brain activity associated with these eigenvectors. We apply random matrix theory to interpret the underlying multivariate data

Antioxidant Networks In vivo

Oxygen interacts with cells and can form highly reactive compounds in vivo known as reactive oxygen species (ROS). High levels of ROS can lead to cellular damage, oxidative stress, heart diseases and cancer. Known substances that are capable of halting the physiological process of oxidation in tissue are called antioxidants.This review covers developments in the field of antioxidant chemistry including interactions between antioxidants and ROS, topics about sources and natural occurrences, classification of antioxidants and a discussion of possible mechanisms. We also summarize examples of oxidative stress biomarkers.

Radio frequency coils for magnetic resonance spectroscopy, medical uses

NRC publication: Ye

Application of 19F magnetic resonance to study the efficacy of fluorine labeled drugs in the three-dimensional cultured breast cancer cells

The cellular monitoring of tumor response to treatments is important for drug discovery and drug development in cancer therapy. We studied efficacy of Herceptin, a common breast cancer drug conjugated with a fluorine organic compound, perfluoro-15-crown-5-ether (PFCE) which easily forms biocompatible emulsions. Three new pharmaceutical forms of Herceptin, Herceptin/PFCE, Herceptin/PFCE/Lipoplex and Herceptin/PFCE/HydraLink were synthesized for the ex vivo study of their efficacy in breast cancer treatment. The emulsions were administered to 109 cells mL-1 of HER-2 positive human adenocarcinoma (MCF-7) cells and the same amount of human mammary epithelial cells (HMEC) cultured in three-dimensional (3D) geometry using hollow fiber bioreactor (HFB) device. Following drugs administration ex vivo, fluorine-19 magnetic resonance imaging (19F MRI) was applied for cells imaging to measure their viability and to study drug efficacy over 72 h. To ensure optimum drug tracking, HydraLink was used to provide stable binding affinity of emulsified Herceptin to receptor while cationic lipid (Lipofectamine) was used to enhance lipophilicity of the emulsions. After 72 h of treatment with Herceptin, Herceptin/PFCE, Herceptin/PFCE/Lipoplex and Herceptin/PFCE/HydraLink the viability of cells was 54 \ub1 2%, 49 \ub1 3%, 43 \ub1 5% and 42 \ub1 1%, respectively, as compared with control 93 \ub1 2%. The efficacy (EC50) of Herceptin conjugated with emulsions was found to be 970 \ub1 13 \u3bcg mL-1 for Herceptin/PFCE, 645 \ub1 11 \u3bcg mL-1 for Herceptin/PFCE/Lipoplex, 678 \ub1 7 \u3bcg mL-1 for Herceptin/PFCE/HydraLink and 1000 \ub1 3 \u3bcg mL-1 for Herceptin. The results show that fluorine emulsions improved the efficacy of Herceptin and 19F signal intensity changes validated drug efficiency. The significant correlations between duration of treatments and MCF-7 cells viability were observed. While we studied breast cancer cells, the fluorine emulsions could be applied for treatment of other cancer cells overexpressing HER-2.Peer reviewed: YesNRC publication: Ye

Detection of fluorine labeled Herceptin using cellular 19F MRI ex vivo

The aim of this study was to assess the Herceptin efficacy in ex vivo cultures of MCF-7 breast carcinoma cells. Herceptin was used with perfluorooctyl bromide (PFOB) and conjugated with Lipoplex, containing plasmid DNA and Lipofectamine (LipA), to allow fluorine-19 magnetic resonance imaging (19F MRI) study. Treatments such as Herceptin, Herceptin/PFOB and Herceptin/PFOB/Lipoplex were used for ex vivo targeting of MCF-7 cells cultured in three-dimensional (3D) geometry using hollow fiber bioreactor (HFB) device. The viability of MCF-7 cells after 72 h treatments decreased to 54 \ub1 2%, 50 \ub1 3% and 45 \ub1 1% for Herceptin, Herceptin/PFOB and Herceptin/PFOB/Lipoplex, respectively. The EC50 values were 1000 \u3bcg/ml, 930 \u3bcg/ml and 730 \u3bcg/ml, respectively. The significant correlation between the treatment concentration and efficacy was observed in MCF-7 cell cultures.Peer reviewed: YesNRC publication: Ye

Technical report 009-VB-001 On 9.15 MHz dual breast coil

Peer reviewed: NoNRC publication: Ye

Technical report 300-QV-12 On 300 MHz quadrature volume coil for ferret imaging in vivo

Peer reviewed: NoNRC publication: Ye

Technical report 75/300 /V/S-001 On set up for rat head proton decoupled \ub9\ub3C spectroscopy in vivo

Peer reviewed: NoNRC publication: Ye

Technical report 008-VB-002 On 8.22 MHz dual breast coil

Peer reviewed: NoNRC publication: Ye

Technical report 015-RXQ-001 On 15.09 MHz four channel phased array coil for spine imaging

Peer reviewed: NoNRC publication: Ye