Masahiro Natsuhori

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Iron incorporation by bovine spleen apoferritin either with ferrous ammonium sulfate in different buffers or with ferrous ammonium sulfate and phosphate was studied. Iron uptake and iron autoxidation were recorded spectrophotomerically. The buffers [4-(2-hydroxyethyl)-1-piperazinyl]ethanesulphonic acid (Hepes) and tris(hydroxymethyl)aminoethane (Tris)(More)
Plasma folates tetrahydrofolate (THF) and N5-methyltetrahydrofolate (5MF) were determined in nongestating, gestating, and lactating sows (2 to 4 yr old, 2-6 parities, n = 88) and in newborn, growing, and finishing pigs (0 to 158 days old, n = 191) with the use of high-performance liquid chromatography with an electrochemical detector. Plasma folates after(More)
Effect of probenecid on pharmacokinetics of 99mTc-mercaptoacetylytriglycine (99mTc-MAG3) in dogs was investigated before (control), and after 15 min and 24 h of i.v. injection of probenecid (20 mg/kg). Plasma concentration-time profiles of 99mTc-MAG3 were described with a two-compartment open model. Plasma 99mTc-MAG3 clearances (Clp, ml/min/kg) were 7.9 +/-(More)
Concentrations of pig plasma folates were determined by a high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Tetrahydrofolic acid (THF) and 5-methyltetrahydrofolic acid (5-MF) were found to be the plasma folates. The concentration of THF (10.3 +/- 4.3 ng/ml) was significantly higher than that of 5-MF (3.5 +/- 1.0 ng/ml). The(More)
The electrophoresis pattern of apoptotic cells detected by the comet assay has a characteristic small head and spread tail. This image has been referred to as an apoptotic comet, but it has not been previously proven to be apoptotic cells by any direct method. In order to identify this image obtained by the comet assay as corresponding to an apoptotic cell,(More)
The relationship between deoxyribonucleic acid (DNA) damage and the cell death induced by gamma-irradiation was examined in three kinds of cells, Chinese hamster ovary fibroblast CHO-K1, human melanoma HMV-II and mouse leukemia L5178Y. Cell survival was determined by a clonogenic assay. The induction and rejoining of DNA strand breaks induced by radiation(More)
Investigating the biological effects of high-LET heavy-ion irradiation at low fluence is important to evaluate the risk of radiation in space. It is especially necessary to detect radiation damage induced by a precise number of heavy ions in individual cells. We thus compared the number of ions traversing a cell and the DNA damage produced by ion hits. We(More)
Stability and protein-binding properties of tetrahydrofolate (THF) in pig plasma were studied in vitro. THF in plasma was stable for more than 120 min when it existed in a bound form, whereas THF both in plasma ultrafiltrate and in plasma ultrafiltrate plus porcine albumin was degraded rapidly and disappeared soon after its addition. These results suggest(More)
We have examined in vitro radiosensitivities and radioresponses to (60)Co gamma-rays irradiation in feline T-lymphocyte cell lines, FeT-J and FL-4. There seemed to be no significant difference in clonogenic survival between the two lines. The mean lethal dose for both was both 1.9 Gy, and surviving fraction at 2 Gy was 0.30 and 0.48 for FeT-J and FL-4(More)
Ferritin utilizes ferroxidase activity to incorporate iron. Iron uptake kinetics of bovine spleen apoferritin were compared with those of recombinant H chain ferritin and L chain ferritin homopolymers. H chain ferritin homopolymer showed an iron uptake rate identical to bovine spleen apoferritin (0.19 and 0.21 mmol/min/μmol of protein, respectively), and(More)