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Biomedical subjects

T Nishimoto

Publications and source records attributed to T Nishimoto.

At least 253 records · Page 14Linked to original sources
PubMed1978

Inhibition of herpes simplex virus type 1 replication in temperature-sensitive cell cycle mutants.

Herpes simplex virus type 1 DNA synthesis and infections progeny production were studied in five different conditional hamster (BHK-21) cell cycle mutants. At the nonpermissive temperature (39.5 degrees C), both events were strongly inhibited in four of these cell lines. The degree of inhibition was a reproducible characteristic of each cell mutant and in two cases was dependent upon the multiplicity of infection. Experiments involving shifts to the nonpermissive temperature at least 3 h postinfection at 33.5 degrees C suggested that the defects in viral replication were not due to faulty adsorption, penetration, or uncoating, whereas experiments involving shifts of infected cells from the nonpermissive temperature to 33.5 degrees C revealed the reversible nature of the inhibition.

Animals↗
PubMed1976

The results of surgical treatment combined with intra-arterial infusion of anti-cancer agents in osteosarcoma.

Since 1963, regional intra-arterial infusion of anti-cancer agents combined with surgery has been used in the treatment of 56 patients with osteosarcomas. The histologic examination of amputated limbs after prolonged intra-arterial infusion therapy showed remarkable degeneration and necrosis throughout wide areas of tumor tissue. The overall estimated 5-year survival rate improved from 4 to 31.4 per cent. In cases where the infusion period was of more than 3 weeks duration, the estimated 5-year survival rate was 43.8 per cent. The period from operation to pulmonary metastasis was prolonged and the incidence of pulmonary metastasis within the first year was markedly decreased. The use of intra-arterial infusion prior to surgery coupled with postoperative bronchial arterial infusion and systemic chemotherapy improved the prognosis in osteosarcomas.

Adolescent↗
PubMed1975

Isolation and properties of a conditionally lethal bacteriophage lambda mutated in the chi region.

A thermosensitive lambda phage mutant was isolated which can grow at high temperature only in the presence of the lambda chi gene product supplied in trans. This mutation tn was mapped within the chi region, and lambda tn phage expressed the pRoR-OP operon only poorly at high temperature. Effects of the tn mutation on expression of other operons were also examined and compared with those observed with cro27 or some tof mutations.

Chromosome Mapping↗
PubMed1975

Temperature-sensitive cell mutations that inhibit adenovirus 2 replication.

Five temperature-sensitive growth mutants of the hamster cell line BHK-21 were tested for the ability to support adenovirus 2 multiplication at 39 degrees and 33 degrees. Wild-type BHK-21 and mutants ts 422E and ts BCH yielded comparable amounts of virus at 33 degrees and 39 degrees, whereas in three other mutants, ts T22, ts T23, and ts AF8, virus production at 39 degrees was reduced to about 1% of that at 33 degrees. Virus yield in the three mutants was not reduced because of a delay in virus production; for all cells tested maximal virus yield at 39 degrees was obtained by 40-50 hr after infection. Normal yields of infectious virus were not obtained from ts AF8 even with a very high multiplicity of infection. In contrast, the virus yield from ts T22 and ts T23 was multiplicity-dependent. Shiftup experiments demonstrated that in ts AF8, a cell cycle mutant which at 39 degrees becomes arrested in G1, virus multiplication was thermosensitive for the first 40 hr of infection. In ts T22 and ts T23, the thermosensitivity was only for the first 3-4 hr of the infection. In all three mutants viral DNA synthesis was reduced by at least 95% at the higher temperature. The cell function specified by the ts AF8 mutation seems to be required for the early period of adenovirus 2 replication, after virus entry into the cell but before the onset of viral DNA replication.

Adenoviridae↗
PubMed1975

A nucleoside triphosphate-dependent deoxyribonuclease from Bacillus laterosporus. The mode of action of the enzyme.

The acid-soluble products of exhaustive digestion of native DNA with Bacillus laterosporus DNase consist of 6.5% of mononucleotides and 93.5% of oligonucleotides with an average chain length of 3.2. The results of viscometric studies and inactivation of transforming DNA indicate the existence of acid-insoluble intermediates and the selective degradation of the population of substrate molecules rather than a random nucleolytic action. Furthermore, sucrose density gradient analysis of partially digested DNA showed that the initial DNA added as a substrate disappeared progressively during the reaction, being replaced by much more slowly sedimenting acid-insoluble materials, which were eventually degraded into acid-soluble end products during the reaction; products intermediate in size between these two components were not detectable. Studies with DNA labeled at the 3'-terminus indicate that Bacillus laterosporus DNase does not attack DNA from 3'-hydroxyl ends to yeild acid-soluble or acid-insoluble materials in a random manner. The results presented in this paper indicate that the nature of the attack of B. laterosporus nuclease is similar to that previously proposed for Micrococcus luteus DNase. The possibility of the sequential release of acid-insoluble intermediate fragments as well as acid-soluble products from the terminal portion of DNA by the enzyme is discussed.

Bacillus↗