川崎医療短期大学における語彙力に関する調査

本稿は,川崎医療短期大学の在学生の語彙力に関する調査結果を報告することを目的とする.2007年度入学生の追跡調査結果では,中学生レベルの語彙力のまま卒業を迎える学生がいることが明らかになった.さらに,入学から1年後は語彙力が伸びるが,2年次以降は語彙力が伸びる学生と伸びない学生の差が顕著であることが明らかになった.今後の課題として,語彙力を継続的に高めていくための方策を検討することが挙げられる

Radioprotectors and Mitigators of Radiation-Induced Normal Tissue Injury

The article reviews agents in clinical use or in development as radioprotectors and mitigators of radiation-induced normal tissue injury

In vivo measurement of tissue oxygen using electron paramagnetic resonance spectroscopy with oxygen-sensitive paramagnetic particle, lithium phthalocyanine

The partial pressure of oxygen (pO2) plays a determining role in the energy metabolism of aerobic cells. However, low pO2 level induces pathophysiological conditions such as tumor hypoxia, ischemia or reperfusion injury, and delayed/altered wound healing. Especially, pO2 level in the tumor is known to be related to tumor progression and effectiveness of radiotherapy. To monitor the pO2 levels in vivo, continuous wave (CW) and time-domain (TD) electron paramagnetic resonance (EPR) spectroscopy method was used, in which surface coil resonator and Lithium phthalocyanine (LiPc) as oxygen sensor wree crucial. Once LiPc particles are embedded in a desired location of organ/tissue, the pO2 level can be monitored repeatedly and non-invasively. This mithod is based on the effect of oxygen concentration on the EPR spectra of LiPc which offers several advantates as follows: (1) high sensitivity, (2) minimum invasiveness, (3) repeated measurements, (4) absence of toxicity (non-toxic), and (5) measurement in a local region of the tissue with embedded LiPc. Therefore, in this chapter, we describe the method using CW and TD EPR spectroscopy with oxygen-sensitive particle, LiPc, for in vivo monitoring of oxygen

Monitoring redox-sensitive paramagnetic contrast agent by EPRI, OMRI and MRI

A comparative study of tissue redox-status imaging using commonly used redox sensitive nitroxides has been carried out using electron paramagnetic resonance imaging (EPRI), Overhauser magnetic resonance imaging (OMRI) and conventional T1-weighted magnetic resonance imaging, MRI. Imaging studies using phantoms of different nitroxides at different concentration levels showed that EPRI and OMRI sensitivities were found to be linearly dependent on line width of nitroxides up to 2 mM, and the enhancement in MRI intensity was linear up to 5 mM. The sensitivity and resolution of EPRI and OMRI images depended significantly on the line width of the nitroxides whereas the MRI images were almost independent of EPR line width.Reduction of the paramagnetic 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3CP) by ascorbic acid (AsA) to the diamagnetic by hydroxylamine was monitored from a sequence of temporal images, acquired using the three imaging modalities. The decay rates determined by all the three modalities were found to be similar. However the results suggest that T1-weighted MRI can monitor the redox status, in addition to providing detailed anatomical structure in a short time. Therefore, a combination of MRI with nitroxides as metabolically responsive contrast agents can be a useful technique for the in vivo imaging probing tissue redox status

Effect of Body Temperature on the Pharmacokinetics of a Triarylmethyl-Type Paramagnetic Contrast Agent Used in EPR Oximetry

Purpose: Pharmacokinetics of tri[8-carboxy-2,2,6,6-tetrakis(2-hydroxymethyl)benzo[1,2-d:4,5-d’]bis(1,3)dithio-4-yl]methyl radical (Oxo63) after a single bolus and/or continuous intravenous infusion was investigated in tumor bearing C3H mice with or without body temperature control while under anesthesia. Meshod: The in vivo time course of Oxo63 in blood was measured using X-band electron paramagnetic resonance (EPR) spectroscopy. Distribution of Oxo63 in normal muscle and tumor tissues was obtained using a surface coil resonator and a 700 MHz EPR spectrometer. The whole body distribution of Oxo63 was obtained by 300 MHz continuous wave (CW) EPR imaging. The high resolution 300 MHz time-domain EPR imaging was also carried out to probe the distribution of Oxo63.Results: Urination of mice was retarded at low body temperature making the concentration of Oxo63 in blood attain high levels. However, the concentration of Oxo63 in tumor tissue was lower with no control of body temperature than active body temperature control. The non-systemized blood flow in the tumor tissues may pool Oxo63 at lower body temperature. Conclusions: Pharmacokinetics of the contrast agent was found to be significantly affected by body temperature of the experimental animal and can influence the probe distribution and the image patterns

Effect of Body Temperature to the Pharmacokinetics of a Triarylmethyl-Type Paramagnetic Contrast Agent Used in EPR Oximetry

Pharmacokinetics of tri[8-carboxy-2,2,6,6-tetrakis(2-hydroxymethyl)benzo[1,2-d:4,5-d’]bis(1,3)dithio-4-yl]methyl radical (Oxo63) after a single bolus and/or continuous intravenous infusion was investigated in healthy and tumor bearing C3H mice with or without body temperature control while under anesthesia. The in vivo time course of Oxo63 in blood was measured using X-band electron paramagnetic resonance (EPR) spectroscopy. Distribution of Oxo63 in normal muscle and tumor tissues was obtained using a surface coil resonator and a 700 MHz EPR spectrometer. The whole body distribution of Oxo63 was obtained by 300 MHz continuous wave (CW) EPR imaging. The high resolution 300 MHz time-domain EPR imaging was also carried out to see the distribution of Oxo63. Urination of mice was blocked under low body temperature. Termination of urinary excretion makes the concentration of Oxo63 in blood maintained at a higher level. However, the concentration of Oxo63 in tumor tissue was lower at low body temperature than at normal body temperature. The non-systemized blood flow in the tumor tissues may be stagnated at lower body temperature. Pharmacokinetics of the contrast agent was found to be significantly affected by body temperature of the experimental animal and can influence the probe distribution and the image patterns.1st QST International Symposium -Quantum Life Science

Probing the intracellular redox status of tumors with magnetic resonance imaging and redox-sensitive contrast agents

Nitroxide radicals are paramagnetic contrast agents, used in magnetic resonance imaging (MRI), that also exert antioxidant effects. Participating in cellular redox reactions, they lose their ability to probide contrast as a function of time after administration. In this study, the rate of contrast loss was correlated to the reducing power of the tissue or the "redox status." The preferential reduction of nitroxides in tumors compared with nomal tissue was observed by MRI. The influence of the structure of the nitroxide on the reduction reate was investigated by MRI using two cell-permeable nitroxides, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidynyloxyl (Tempol) and 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3CP), and one cell-impermeable nitroxide, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl (3CxP). Pharmacokinetic images of these nitroxides in normal tissue, tumor, kidney, and artery regions in mice were simultaneously obtained using MRI. The decay of Tempol and 3CP in tumor tissue was significantly faster than in normal tissue. No significant change in the total nitroxide (oxidized + reduced forms) was noted from tissue extracts, suggesting that the loss in contrast as a function of time is a result of intracellulat bioreduction. however, in the case of 3CxP (membrane impermeable), there was no difference in the reduction rates between normal and tumor tissue. The time course of T1 enhancement by 3CxP and the total amount of 3CxP (oxidized + reduced) in the femoral region showed similar pharmacokinetics. These results show that the differential bioreduction of cell-permeable nitroxides in tumor and normal tissue is supported by intracellular processes and the reduction rates are a means by shich the intracellular redox status can be assessed noninvasively