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Volume 21, Issue 2
Displaying 1-6 of 6 articles from this issue
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T. MASUDA, A. MINEMURA, K. YAMAUCHI, M. KONDO1980 Volume 21 Issue 2 Pages 149-156
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSA mechanism of direct photoreduction of ferricytochrome c was investigated by using continuous UV-irradiation and flash photolysis. The photoreduction was found to follow a biphotonic process and to be considerably suppressed by nitrous oxide and oxygen. The fact that urea caused an increase in the rate of photoreduction suggests that the close contact of tryptophyl residue with the heme was lost. Participation of tryptophyl residue was confirmed by the efficiency of aromatic amino acids on indirect photoreduction and a transient absorption with a peak at about 530 nm in the presence of urea. The quantum yield of the photoionization was estimated to be (3.9 ± 0.3)×10-3. A mechanism is proposed that the hydrated electrons produced by the photoionization of aromatic amino acid residue(s), tryptophyl and tyrosyl, take part in the photoreduction of ferricytochrome c.View full abstractDownload PDF (341K) -
V. C. SHAH, P. K. GADHIA1980 Volume 21 Issue 2 Pages 157-162
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe changes in the activities of acid phosphatase in the sham-irradiated and γ-irradiated cerebellum of pigeons have been studied both biochemically as well as histochemically after 400 rads. The specific activity of acid phosphatase decreased significantly after 48h and 72h of irradiation. The histochemical observations following total body irradiation confirmed the results obtained by quantitative biochemical studies.View full abstractDownload PDF (637K) -
GEETA KAPOOR, P. N. SRIVASTAVA1980 Volume 21 Issue 2 Pages 163-172
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSOvaries of immature mice (one, two and three weeks old) were maintained in culture containing tritiated water at the dose of 5 μCi/ml of medium. After 72 hours, ovaries in culture showed considerable degeneration. All primordial oocytes were affected in the irradiated groups. The granulosa layers show a marked decrease in their cell number in all culture samples. Lowlevel exposure to beta radiation from tritium is capable of inflicting considerable damage to the ovarian cell system of Swiss albino mice in vitro.View full abstractDownload PDF (788K) -
T. MASUDA, H. SHINOHARA, M. EDA, M. KONDO1980 Volume 21 Issue 2 Pages 173-179
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSRate constants for the reactions of hydroxyl radicals with nucleotides, polynucleotides, and related compounds were determined with a competition method using p-nitrosodimethylaniline. Reactivity of mononucleotides toward hydroxyl radicals decreases with increasing number of phosphate group. For polynucleotides, the reactivity per nucleotide unit was found to be much less than the corresponding mononucleotide and to depend on their conformation. The more rigid the conformation, the smaller the rate constant. The reactivity of polynucleotides was enhanced after heat-treatment at 80°C. The results are discussed in terms of steric hindrance and of reaction of a macromolecule with a small molecule in aqueous solution.View full abstractDownload PDF (338K) -
TETSUYA ISHIDA, HIROKAZU KATO, JUNJI MIYAKOSHI, MASAYO FURUKAWA, SUSUM ...1980 Volume 21 Issue 2 Pages 180-189
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSIn order to utilize RF hyperthermia for the clinical cancer therapy, the development in dosimetry of the RF absorbed power in situ is considered to be necessary. In the present experiments, it was clarified that RF absorbed power distribution in agar-physiological salt solution phantom can be estimated from time variation of temperature which is measured by a fine thermocouple introduced to the phantom after heating process.View full abstractDownload PDF (330K) -
TAKESHI YAMADA, HARUMI OHYAMA1980 Volume 21 Issue 2 Pages 190-196
Published: July 15, 1980
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSRadiation-induced changes in the surface morphology of rat thymocytes in suspension were evaluated by scanning electron microscopy. Viable (erythrosin B unstainable) cells were gene. rally rounded with their surface exhibiting undulations of short microvilli. Exposing the cell suspension to 1 kR X-rays and 4 hour incubation at 37°C caused disappearance of microvilli. Association of dead (erythrosin B stainable) thymocytes with smooth, occasionally porous, surface without any digitations was confirmed by the examination of enriched dead cell populations.View full abstractDownload PDF (324K)
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