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Biomedical subjects

S Seki

Publications and source records attributed to S Seki.

At least 415 records · Page 23Linked to original sources
PubMed1982

Blur-induced changes in the visual evoked potential.

Binocular vision has several advantages as compared with monocular vision. In this study, objective recordings of binocular functioning were studied with visual evoked potentials (VEP's). Lenses from plano through +1.50 D were added to reduce acuity monocularly and binocularly. Results indicate that the VEP, while sensitive to binocularly induced blur, does not reflect the changes in binocular vision which are produced by monocularly induced blur. The high contrast of the visual stimulus pattern (97%) may be responsible for the absence of attenuation during binocular viewing while one eye is blurred.

Adult↗
PubMed1980

Differential effects of aphidicolin on replicative DNA synthesis and unscheduled DNA synthesis in permeable mouse sarcoma cells.

Aphidicolin clearly discriminated replicative DNA synthesis from unscheduled DNA synthesis. Aphidicolin inhibited replicative DNA synthesis in permeable mouse ascites sarcoma cells. The mode of inhibition of aphidicolin was a mixed type with respect to deoxycytidine triphosphate but was non-competitive with respect to the other three deoxynucleoside triphosphates. Aphidicolin did not affect the activity of unscheduled DNA synthesis in either bleomycin-treated permeable sarcoma cells or isolated rat liver nuclei. Considering the difference in sensitivity of DNA polymerase alpha and beta to aphidicolin, and other related information reported previously, the results are compatible with the idea that DNA polymerase alpha is involved in replicative DNA synthesis and DNA polymerase beta in unscheduled DNA synthesis in the present systems.

Animals↗
PubMed1980

Replicative DNA synthesis and unscheduled DNA synthesis in permeable sarcoma cells studied by nuclease digestion.

About 20% of DNA replicated in vitro in permeable mouse ascites sarcoma cells showed higher sensitivity to staphylococcal nuclease than the sensitivity of bulk DNA, and the remaining part showed the same nuclease sensitivity as that of parental chromatin DNA. The sensitivity of DNA replicated in permeable cells was higher than that of DNA newly replicated in vivo in intact cells, and close to that of DNA newly replicated in vivo in the presence of cycloheximide. Bleomycin-induced unscheduled DNA synthesis in permeable cells was highly sensitive to the nuclease. The results suggest that DNA replicated in vitro and parental nuclear protein form immature nucleosomes, probably in the same way as in vivo chromatin replication in the presence of protein synthesis inhibitors. It also appears that bleomycin-induced, unscheduled DNA synthesis occurs largely in the internucleosomal region.

Animals↗