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S Kasugai

Publications and source records attributed to S Kasugai.

42 records · Page 3Linked to original sources
PubMed1990

Measurements of the isometric contractile forces generated by dog periodontal ligament fibroblasts in vitro.

One hypothesis for the mechanism of tooth eruption is that the periodontal ligament fibroblasts generate the eruptive force. To assess the force generated, these fibroblasts were obtained by explant culture of ligament from mandibular premolars of a dog and were cultured in collagen gel matrices. The forces generated by them under isometric conditions were continuously measured for 120 h with a strain gauge. At the same time the number of cells in the gel was counted and the force measured was calculated as the force generated by 10(4) cells. Shortly after the start of culture, the force per 10(4) cells increased rapidly; it reached 5.2 X 10(-4) N at 8 h, and then remained at the same level for about 48 h. Our findings suggest that fibroblasts of the periodontal ligament may generate sufficient force for tooth eruption.

Animals↗
PubMed1990

A simple in vito cytotoxicity test using the MTT (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay: analysis of eugenol toxicity on dental pulp cells (RPC-C2A).

A simple colorimetric assay using MTT has been developed to monitor mammalian cell survival and proliferation in vitro. In this study we used a clonal fibroblastic cell line (RPC-C2A) from, rat incisal dental pulp to examine the effectiveness of the colorimetric assay to test for the toxicity of eugenol, which is frequently used to treat inflammed dental pulp. A technical problem encountered was the insolubility of MTT formazan, produced by the activity of mitochondria dehydrogenases. Dimethyl sulfoxide (DMSO) seemed to be the best solvent. Doses of eugenol causing a 50% inhibition in the colorimetric assay were calculated as 0.6 mM and 1 mM for cells in the growing phase and for cells at confluence, respectively. These values exist in the concentration range reported in the previous studies. Although the correlation between spectrophotometric absorbance and cell number was not completely linear, this method could be used effectively as a simple preliminary assay to test for the toxicity of dental drugs and materials.

Cell Survival↗
PubMed1988

Establishment and characterization of a clonal cell line (RPC-C2A) from dental pulp of the rat incisor.

Maxillary incisor pulp cells from male Wistar rats (7 weeks old) were cultured. After the 52nd subculture, cloning was performed twice and a clonal cell line (RPC-C2A) with high alkaline phosphatase (ALP) activity was established. The population doubling time of RPC-C2A cells was 13.7 h, and the mode of the chromosome number was 42. The heat stability of ALP, the effect of the ALP inhibitors, and the ALP polyacrylamide gel electrophoresis pattern in RPC-C2A cells was the same as for the ALP of the isolated dental pulp.

Alkaline Phosphatase↗
PubMed1983

Autoradiographic study using 3H-thymidine on rat incisal pulp cells in vitro.

An autoradiographic study using 3H-thymidine (3H-TdR) was carried out to investigate which cells migrate from the pulp explant of the rat incisor in vitro. The cells close to the arterioles (perivascular cells) were especially labeled after 3H-TdR incubation following the dissection of the pulp explant. In tracing these 3H-TdR-labeled perivascular cells, about 15 per cent of the outgrowth cells were the perivascular cells after 2 days of culture and these perivascular cells had a high mitotic activity in vitro. On the other hand, it was ascertained that the odontoblasts in the pulp explant underwent necrotic changes and that the odontoblasts had no ability to migrate from the pulp explant.

Animals↗