Search PubMed⌕ Search

Biomedical subjects

Y Yagi

Publications and source records attributed to Y Yagi.

At least 289 records · Page 16Linked to original sources
PubMed1978

Evaluation of fibergastroscopic biopsy in the diagnosis of gastric cancer: a study of 339 cases.

Three hundred and sixty-five biopsies under direct vision, using a fibergastroscope, were performed on 339 patients with gastric cancer from 1966 to 1975. Diagnostic accuracy improved with an increased in the number of biopsy specimens and reached 100% when 6 or more biopsy specimens were obtained. Positive specimens were obtained with 48.5% of the biopsied tissue from the center of the lesion (A), 52.2% from the inner margin of the lesion (B1), 19.6% from the outer margin of the lesion (B2), and 1.6% from the area around the lesion (C). The combined result of the biopsies from A and B1 was highly positive in 49 out of 51 cases (96.1%). Diagnostic accuracy of the early cancer reached 96.9%. This was significantly higher than that of advanced cancer (80.3%). False negative biopsies were found in 51 (16.3%) of the 313 patients who were gastrectomized and diagnosed by histological examinations. Twenty-three of the 27 patients, who were diagnosed as benign either by x-ray or endoscopic examination, and 4 of the 5 patients who were diagnosed as benign under both examinations, were found to have positive results by biopsy. Positive biopsy examination was particularly helpful with patients showing on inconclusive or benign diagnosis by x-ray and/or endoscopic examinations.

Biopsy↗
PubMed1978

Characterization of a small plasmid determining resistance to erythromycin, lincomycin, and vernamycin Balpha in a strain of Streptococcus sanguis isolated from dental plaque.

A plasmid determining resistance to erythromycin (inducible), lincomycin, and vernamycin B(alpha) was isolated from a strain of Streptococcus sanguis isolated from dental plaque of a patient who had been on erythromycin therapy for an extended period of time. The plasmid, designated pAM77, had a molecular weight of 4.5 x 10(6) and was present to the extent of one to two copies per bacterial chromosome. The plasmid could transform S. sanguis strain Challis.

Anti-Bacterial Agents↗
PubMed1977

Phthalic acid esters in various foodstuffs and biological materials.

Phthalic acid esters (PAEs) are ubiquitous environmental contaminants in Japan. Di-n-butyl phthalate (DNBP) and di-2-ethylhexyl phthalate (DEHP) are the most commonly found of nine PAEs examined. DNBP and DEHP residues in 22 kinds of commerical foodstuffs (55 examples), mostly in plastic containers, are recorded. The level is generally higher in powdered foodstuffs than in other materials and the content of PAEs increased sharply during their storage. A close correlation is found between the content of PAE residues in packing materials and those of foodstuffs. The levels of DNBP and DEHP in human blood samples are found to be much higher than those of PCBs.

Adult↗
PubMed1977

Identification and characterization of a small sequence located at two sites on the amplifiable tetracycline resistance plasmid pAMalpha1 in Streptococcus faecalis.

Streptococcus faecalis DT-11 harbors the 6.0-megadalton plasmid pAMalpha1, which determines resistance to tetracycline (TC). When this strain is grown in the presence of TC for a number of generations, a reversible gene amplification occurs, generating tandem repeats of a 2.65-megadalton segment of the plasmid. On the basis of heteroduplex studies between various forms of pAMalpha1 and fragments generated by the Escherichia coli restriction endonuclease EcoRI, we have obtained direct evidence for the presence of a small sequence designated RS1 (for recombination sequence) located on both sides of the TC resistance determinant. Corresponding points on the two sequences are separated by 2.65 megadaltons of deoxyribonucleic acid. The two RS1 sequences have the same polarity and are of a size corresponding to about 380 nucleotide base pairs. The data presented serve as strong support for amplification models that are based on recombinational events involving the RS1 sequences.

Base Sequence↗
PubMed1976

Formation of lipoperoxide in isolated sciatic nerve by chinoform-ferric chelate.

Effects of chinoform and chinoform-ferric chelate on formation of lipoperoxide in isolated sciatic nerve were investigated. Free chinoform did not increase the lipoperoxide level, while chinoform-ferric chelate significantly increased it. Assuming that the lipoperoxide formed denatures the associated protein in the nerve, the effect of chinoform-ferric chelate could explain, at least partly, the demyelination of nerve tissues caused by massive doses of chinoform.

Animals↗
PubMed1975

Plasmid-determined tetracycline resistance in Streptococcus faecalis: evidence for gene amplification during growth in presence of tetracycline.

The tetracycline (TG)-resistant Streptococcus faecalis strain DS-5Cl harbors two plasmids designated alpha and gamma with molecular masses of approximately 6 and 35 million daltons, respectively. TC-sensitive variants were derived by storing cells at 45 degrees for 2-3 weeks. Analysis of covalently closed circular DNA from five such variants (derived independently) revealed that in each variant the alpha-plasmid, which normally sediments at 28 S (supercoiled) in a sucrose density gradient, was replaced by a 22S substance. Growth of DS-5Cl in the presence of 150 mug/ml of TC (minimum inhibitory concentration is 250 mug/ml in liquid broth) for a prolonged period of time (50-60 generations) resulted in the disappearance of 28S DNA and the appearance of a heterogeneous covalently-closed circular DNA sedimenting at about 40-48 S. This phenomenon was accompanied by an increase in the level of bacterial TC-resistance, whereby tells were subsequently grown in the absence of TC for 70-80 generations, the heterogeneous DNA disappeared and a typical 28S alpha-plasmid reappeared. The cells also became less resistant to TC, i.e., the minimum inhibitory concentration returned to 250 mug/ml. These data suggest that bacterial growth in the presence of TC results in a reversible gene amplification with respect to a TC-resistant determinant residing on the alpha-plasmid.

Cell Division↗
PubMed1974

Characterization of three plasmid deoxyribonucleic acid molecules in a strain of Streptococcus faecalis: identification of a plasmid determining erythromycin resistance.

Three plasmids designated alpha, beta, and gamma, distinguishable by their molecular weights (6, 17, and 34 million, respectively) were isolated from Streptococcus faecalis strain DS-5 (ATCC 14508). Derivatives of this strain "cured" for erythromycin resistance lacked the beta-plasmid. In the parent strain the beta-plasmid was estimated to be present to the extent of one to two copies per chromosomal genome equivalent whereas the alpha- and gamma-plasmids were about nine and five copies, respectively.

Acridines↗