Search PubMed⌕ Search

Biomedical subjects

T Takaya

Publications and source records attributed to T Takaya.

84 records · Page 5Linked to original sources
PubMed1982

Some properties of starches of opaque-2, sugary-2 opaque-2, and waxy opaque-2 mutants of two broad-based synthetic cultivars of maize.

Starches of the opaque-2, sugary-2, opaque-2, and waxy opaque-2 endosperm mutants of two broad-based synthetic cultivars (Temp HA and Temp HB) of maize adapted to the more temperate areas of the world are, in general, similar to the respective starches of inbred maize background with regard to amylose percentage and the distribution of linear alpha-D-(1 leads to 4) linked unit-chains of amylopectin, starch-granule susceptibility to amylases, and properties examined by X-ray diffractometry and photopastegraphy. Changes in starch content and morphology of starch granules by scanning electron microscopy in dissected endosperms of the two broad-based synthetic maize cultivars following germination 0, 2, 4 and 6 days after planting were also investigated.

Amylases↗
PubMed1981

Studies on beta-lactam antibiotics. II. Synthesis and structure-activity relationships of alpha-hydroxyiminoarylacetyl cephalosporins.

The synthesis and antibacterial activity in vitro of the 2-aryl-2-hydroxyiminoacetyl cephalosporins (2) are described. Within this cephalosporin series, analogs (9f approximately 13f) with 2-hydroxyimino-2-(3-hydroxyphenyl)acetyl group at the 7-position of a cephem nucleus were found to have the highest antibacterial activity against a wide-range of microorganisms, including beta-lactamase-producing bacteria. Structure-activity relationships of 2 are discussed.

Bacteria↗
PubMed1981

Studies on beta-lactam antibiotics. III. Synthesis and enzymatic stability of 3-acyloxymethyl-7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(methoxyimino)acetamido]-3-cephem-4-carboxylic acids.

3-Acyloxymethyl-7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(methoxyimino) acetamido]-3-cephem-4-carboxylic acids (7) were synthesized. The stability of 7 to enzymatic hydrolysis and their antimicrobial activity were evaluated. 7 showed good antimicrobial activity against a wide range of microorganisms. Cephems (7b and 7c) with sterically more hindered acyl groups such as t-butyl and cyclohexyl were most resistant to enzymatic hydrolysis.

Animals↗
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.

Ascites↗