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Biomedical subjects

Y Kashiki

Publications and source records attributed to Y Kashiki.

31 records · Page 2Linked to original sources
PubMed1975

Pathophysiology of aganglionic colon segment: an experimental study on aganglionosis produced by a new method in the rat.

Experimental aganglionosis was produced successfully in a colonic segment proximal to the peritoneal reflection by intraluminal filling under tension of the colorectum of rats with 0.01% corrosive sublimate in normal saline solution. Where the length of aganglionic segment was more than 3 cm, ileus appeared and megacolon proximal to a narrow segment was observed. Histologically and histochemically, a total denervation state was observed in the aganglionic segment, in contrast to findings in narrow segments of Hirschsprung's disease, in which intramural extraneous nerves are known to be increased. The fact that a definite narrow segment like that seen in Hirschsprung's disease appeared at the portion of the colon in which experimental aganglionosis was produced indicates that a narrow colonic segment certainly can be produced without presence of any intramural extraneous nerves, although the possibility that the presence of such nerves may exaggerate the narrowing cannot be denied. The fact that the cases in which length of aganglionosis was less than 2.5 cm did not have an ileus suggests that there may be some contributing factors other than aganglionosis in the etiology of Hirschsprung's disease of ultrashort segment, if this entity of the disease really exists. Aperistalsis observed in experimental aganglionic segments and that observed in aganglionotic segments of Hirschsprung's disease seem to be based on a common main factor, i.e., absence of the nonadrenergic, noncholinergic nerves.

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PubMedDate not supplied

Application of telomerase activity for screening of primary lung cancer in broncho-alveolar lavage fluid.

Telomerase is a ribonucleoprotein that synthesizes telomeric DNA onto chromosomal ends using an RNA component as a template. Extension of telomeric repeats by telomerase prevents telomere shortening with cell divisions and contributes to chromosomal stability, possibly leading to immortalization of the cells. In the present study, we used a telomerase assay to detect primary lung cancer in broncho-alveolar lavage fluid (BALF). A total of 58 BALF samples were examined by telometric repeat amplication protocol assay. Thirty-five (29 cancers, 2 salcoidoses, 2 pulmonary tuberculoses and 2 normal samples) of 58 (60.3%) cases were found to be positive for telomerase activity. The sensitivity of telomerase activity was 78.4%, compared with 64.7% of BALF cytology. Among 37 primary lung cancer patients diagnosed histopathologically, 24 had positive cytology and 29 had positive telomerase activity. The number increased to 32 patients when cytodiagnosis and telomerase activity were considered. Of patients in whom the presence of primary lung cancer was strongly suspected clinically, although there was no histopathological evidence, two were telomerase-positive, initially diagnosed as normal by cytological examination and histological examination but finally diagnosed as primary lung cancer (adenocarcinoma) in subsequent histological examination using operation specimens. These findings suggest that telomerase assay using BALF samples might be a useful screening method for primary lung cancer especially when combined with BALF cytology.

Aged↗
PubMedDate not supplied

Cytological diagnosis and telomerase activity of cells in effusions of body cavities.

Telomerase is a ribonucleoprotein that synthesizes telometric DNA on chromosome ends, and may be related to the aging and immortality of cells. Recently, a telometric repeat amplification protocol (TRAP) assay for telomerase activity, using the polymerase chain reaction, was developed. We examined the limitations of TRAP assay by applying it to a cultured colon cancer cell line (COLO320) and 58 human cytological materials from body cavity effusions, and obtained the following results; i) The limits of the TRAP assay were 20-50 cells for the COLO320 cell line; ii) One COLO320 cell per 100 normal blood white cells was detectable; iii) Seventeen of 58 samples were positive for telomerase activity in this study. The sensitivity was 69% (9/13) and the specificity was 87.5% (28/32) between cytological diagnosis and telomerase activity; iv) Among 29 malignant cases, 15 were positive for telomerase activity, while there were 11 cytologically positive cases. The positive cases detected by the combination of cytology and telomerase activity accounted for 21 of the total 29 cases (72.4%). These results suggest that the measurement of telomerase activity in body cavity effusions may be useful as an adjunctive tool for cytological and clinicopathological diagnosis and that this technique is potentially applicable to remnant cytological materials.

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