Quantum Sensors To Track Total Redox-Status and Oxidative Stress in Cells and Tissues Using Electron-Paramagnetic Resonance, Magnetic Resonance Imaging, and Optical Imaging.

Total redox capacity (TRC) and oxidative stress (OxiStress) of biological objects (such as cells, tissues, and body fluids) are some of the most frequently analyzed parameters in life science. Development of highly sensitive molecular probes and analytical methods for detection of these parameters is a rapidly growing sector of BioTech's R&D industry. The aim of the present study was to develop quantum sensors for tracking the TRC and/or OxiStress in living biological objects using electron-paramagnetic resonance (EPR), magnetic resonance imaging (MRI), and optical imaging. We describe a two-set sensor system: (i) TRC sensor QD@CD-TEMPO and (ii) OxiStress sensor QD@CD-TEMPOH. Both redox sensors are composed of small-size quantum dots (QDs), coated with multinitroxide-functionalized cyclodextrin (paramagnetic CD-TEMPO or diamagnetic CD-TEMPOH) conjugated with triphenylphosphonium (TPP) groups. The TPP groups were added to achieve intracellular delivery and mitochondrial localization. Nitroxide residues interact simultaneously with various oxidizers and reducers, and the sensors are transformed from the paramagnetic radical form (QD@CD-TEMPO) into diamagnetic hydroxylamine form (QD@CD-TEMPOH) and vice-versa, because of nitroxide redox-cycling. These chemical transformations are accompanied by characteristic dynamics of their contrast features because of quenching of QD fluorescence by nitroxide radicals. The TRC sensor was applied for EPR analysis of cellular redox-status in vitro on isolated cells with different proliferative indexes, as well as for noninvasive MRI of redox imbalance and severe oxidative stress in vivo on mice with renal dysfunction.

Coronary Artery Bypass Grafting in the Presence of Atherosclerotic Lesions in the Ascending Aorta / 日本心臓血管外科学会雑誌

The results and surgical techniques were studied in 59 patients who had atherosclerotic lesions in the ascending aorta. Arterial grafting (AG) and sequential grafting for coronary artery bypass grafting (CABG) was used in as many as possible cases and the number of distal anastomoses with AG was 1.3/patient (internal thoracic artery (ITA), 56 anastomoses for 50 patients; gastroepiploic artery (GEA), 17; and inferior epigastric artery, 3). Calcification in the ascending aorta was noted in 26 patients and arterial cannulation was performed via the right axillary artery in 4 patients. Saphenous vein grafts were used for 51 patients and 30 of them required aortic reconstruction for proximal anastomosis. There were 2 hospital deaths (non-cardiac) and no neurological complications. It is difficult to perform CABG in the presence of atherosclerosis in the ascending aorta. However, the right axillary artery cannulation as the site of arterial cannulation and the use of sequential grafting, using ITA and GEA as the pedicled arterial conduits are useful to accomplish CABG in such patients. Neurological complication seems to be manufactured at a minimal level by cautious operative techniques.