Masako Furuse

Increased expression of intracisternal A-particle RNA in regenerated myeloid cells after X irradiation in C3H/He inbred mice.

Abstract Ishihara, H., Tanaka, I., Furuse, M. and Tsuneoka, K. Increased Expression of Intracisternal A-Particle RNA in Regenerated Myeloid Cells after X Irradiation in C3H/He Inbred Mice. Myeloid leukemia cells were derived from regenerated hematopoietic cells damaged by sublethal doses of X radiation in C3H/He inbred mice. We previously found that within the genome of the myeloid leukemia cells, a retrotransposon, the intracisternal A-particle (IAP) element, is integrated. Levels of IAP RNA, the source of cDNA for the integration, were analyzed quantitatively in C3H mice. Higher levels of IAP transcripts were observed in normal cells, particularly in hematopoietic cells, from C3H/He mice, than in those from C57BL/6J and STS/A mice. In the C3H/He mice, an approximately twofold increase in IAP RNA was found in the regenerated spleen and bone marrow cells at 5 days and from 12 to 90 days after whole-body X irradiation. In addition, an increased level of IAP RNA was observed in all the myeloid leukemia cells derived from C3H/He mice. This suggests that the elevated levels of IAP RNA in the regenerated hematopoietic cells after irradiation contribute to the increase in retrotransposition of IAP found in myeloid leukemia cells from C3H/He mice.

Inactivation measurements of yeast along the path of 135 MeV/amu carbon for a beam monitor in medical applications

Abstract The survival ratios of yeast cells as a function of carbon beam penetration into a plastic block were evaluated at an initial energy of 135 MeV/amu. The cells were inserted into holes at several depths along the beam path. We estimated the inactivation ratios of both the haploid and the budding response of the haploid cell for the wild and the sensitive strain at stationary and growth phase. The ratios along the beam path were applicable as a method of beam adjustment in the planning of heavy ion therapy

APPLICATIONS OF PIXE ANALYSIS TO STUDIES IN CELL BIOLOGY

PIXE application to the measurement of cellular elements is outlined on characteristic variations of the contents of yeast, CHO, V79 and MM46 cultured mammalian cells according to environmental changes. Cellular elements from P to Br were successfully analyzed at these cells after cautious preparation of samples in filtration steps with as possible as less deterioration. We confirmed linear relationships between the X-ray yields and these element contents. The experiment was extended to an analysis of cellular substances at molecular level by scanning of specimens. Preliminary results were included.