Search PubMed⌕ Search

Biomedical subjects

M Yagi

Publications and source records attributed to M Yagi.

At least 235 records · Page 13Linked to original sources
PubMed1985

[A case of remission in diffuse pleural mesothelioma induced by anticancer chemotherapy with cisplatin and adriamycin].

A 56-year-old man was admitted to our hospital with complaints of dyspnea and right pleural effusion. Malignant pleural mesothelioma was diagnosed, based on the high level of hyaluronic acid in the pleural fluid and manifestation of malignant cells by pleural needle biopsy. Anticancer chemotherapy with cisplatin and intrapleural injections of adriamycin against this mesothelioma was carried out because of the presence of stage III by Butchart's classification. Regression of the tumor, decrease of pleural fluid and decrease of LDH level in effusions were observed after this chemotherapy. Cisplatin was easily transported into the pleural fluid, and its concentration was maintained for a satisfactorily long period.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Oxidation of benzo(a)pyrene and 7,8-dihydro-7,8-dihydroxy benzo(a)pyrene by horseradish peroxidase-H2O2 intermediate: fluorometric study.

The capacity of oxidation of benzo(a)pyrene (BP) and its analog to be oxidized by peroxidases in several tissues has been studied. The kinetics of the horseradish peroxidase (HRP) oxidation of BP and 7,8-dihydro-7,8-dihydroxy benzo(a)pyrene (BP-7,8-diol) were examined. Effective ratios of H2O2 and HRP for catalytic oxidation were 13.74 for BP and 4.58 for BP-7,8-diol. The maximum ratio was approximately 90 for both hydrogen donors (BP and BP-7,8-diol) to the ES complex. The maximum ratio of oxidized BP and BP-7,8-diol to HRP was 5.7. Ks values for H2O2 were 1.68 and 6.35 microM for BP and BP-7,8-diol, respectively. The mean values of the rate constants, k5, for the oxidation of BP and BP-7,8-diol were 0.56 X 10(5) M-1 sec-1 and 4.1 X 10(5) M-1 sec-1, respectively, at low concentrations. At low concentrations a Hill plot of the oxidation of BP showed a negative value (nH = 0.5) and at high concentrations nH = 1.0. On the other hand, that of BP-7,8-diol showed positive cooperativeness (nH = 1.8). These oxidation reactions caused substrate (donor) inhibition at high concentrations. The inhibition constants, KA', were 9.8 and 5.65 microM for BP and BP-7,8-diol, respectively. The reactivity of the oxidation of BP-7,8-diol was five to six times larger than that of BP.

Benzo(a)pyrene↗
PubMed1984

Binding of benzo(a)pyrene with peroxidase and its oxidation by peroxidase-H2O2 intermediate.

The oxidation of benzo(a)pyrene (BP) by horseradish peroxidase (HRP) (EC 1.11.1.7) was examined spectrophotometrically by the decomposition of peroxidase-H2O2 intermediate "compound II." The rate constant of the oxidation of BP was 9.5 X 10(4) M-1 sec-1. The oxidation of BP by HRP was inhibited at high BP concentrations, and the hydrogen donor (BP) inhibition constant, KA', was 1.48 microM. The association constant, Kassoc, of the formation of a complex of BP and HRP at 403 nm was 4.37 X 10(4) M-1. The oxidation products of BP have been identified as 1,6-, 3,6- and 6,12-quinone BP. These products showed no mutagenicity in the mutagenicity assay.

Benzo(a)pyrene↗
PubMed1984

[The appraisal of biliary drainage for intrahepatic gall stones, with special reference to an end-to-side hepaticojejunostomy].

Between 1961 and 1983, eighty-six patients with intrahepatic gall stones were identified from a group of 1,140 patients admitted for cholelithiasis. Surgical procedures performed in this series were 37 choledochotomies with external biliary drainages, 33 transduodenal papilloplasties, 37 bilioenteric anastomosis and 15 hepatectomies. In the long term follow up studies after surgical treatment by each procedures, the favorite results were obtained in 41.2% of cases with choledochotomies with external drainages, in 34.4% of cases with transduodenal papilloplasties, in 82.4% of cases with bilioenteric anastomosis and in 88.7% of cases with hepatectomies. Hepatectomy seemed to be a most effective treatment for the prevention of recurrence of stones. However, if the calculi were in the right or both of hepatic lobes, hepatectomy might be a high risk operation and technical proficiency were required in operation. In such cases, we performed an end to side anastomosis between the common hepatic duct and the jejunum (Roux en Y anastomosis) for the postoperative endoscopic lithotomy. In this operation the jejunal stump was made to be an enterocutaneous fistula for the later percutaneous endoscopic lithotomy. This operation has the following advantages; 1) the time of operation were shortened in the removal of stones because of this operation were performed for the postoperative endoscopic lithotomy, 2) retrograde cholangitis was less likely to develop than other operations, 3) retained stones dropped into bowel easily by making a big anastomotic stoma, 4) the cholangioscope could be inserted into either bile ducts of the right and left hepatic lobes, 5) the fistula would be able to be reused for the endoscopic treatment at later recurrence of intrahepatic gall stones.

Adult↗
PubMed1984

[A case of primary adenosquamous carcinoma of the stomach associated with gastric polyposis].

We report a 76-year-old woman with Borrmann 3 carcinoma associated with gastric polyposis, who underwent total gastrectomy and splenectomy. Histopathological study of resected specimens revealed squamous cell carcinoma in some sections keratinization was seen; other sections evidenced adenocarcinoma. Due to intra- acinous epithelial stratification and platyform development, the adenosquamous carcinoma was considered to have originated from squamous epithelial metaplasia of the adenocarcinoma cells. Of 90,639 patients who had undergone resection to treat gastrocarcinoma, 236 (0.26%) had adenosquamous carcinoma. However, only 7 cases were associated with polyposis.

Adenocarcinoma↗
PubMed1983

Restriction endonuclease mapping of gamma-delta-beta-globin region in G gamma (beta)+ HPFH and a Chinese A gamma HPFH variant.

Restriction endonuclease mapping of the beta-globin genomic region was used for studying the molecular basis of two variants of hereditary persistence of fetal hemoglobin (HPFH): an African G gamma (beta)+ HPFH and a Chinese HPFH variant with predominant synthesis of A gamma chains. HPFH and control DNA samples were digested with a battery of restriction enzymes, and the fragments were identified by hybridization to a family of discrete probes. DNA fragments from the A gamma HPFH (Chinese) and the G gamma (beta)+ HPFH individuals were identical with those of the normal controls. These findings suggest that the two mutants are the result of small structural anomalies of DNA sequences that play a role in the regulation of the expression of gamma-globin genes.

Chromosome Mapping↗
PubMed1983

[Localized amyloidosis of the ureter: report of a case].

A case of primary amyloidosis of the ureter is presented. The patient was a 48-year-old woman with a 5-year history of asymptomatic macrohematuria. Roentgenographic examination showed left hydronephrosis and stenosis of the left distal ureter. Histological examination of the biopsied specimen during the operation revealed no malignancy; and, left partial ureterectomy and uretero- vesiconeostomy was performed. Congo red stain proved amyloid deposition after surgery. Rectal biopsy was negative for amyloid; and, other laboratory findings were within normal range. Thus it was diagnosed as a primary localized amyloidosis of the ureter. Importance of intraoperative histologic examination was discussed. This is the 22nd case in the literature.

Amyloidosis↗
PubMed1982

J chain is encoded by a single gene unlinked to other immunoglobulin structural genes.

Immunoglobulin J chain mediates the polymerization of both IgM and IgA immunoglobulins. Its synthesis is closely regulated in B lymphocytes, apparently at the level of RNA transcription. To define the genetic bases of this regulation, we have determined the location and number of J chain genes in the mouse. Analysis of DNA from a group of somatic cell hybrids containing various mouse chromosomes on a constant background of Chinese hamster chromosomes indicated that this gene is located on mouse chromosome 5, unlinked to immunoglobulin heavy and light chain structural genes. Restriction mapping experiments further suggested the existence of a single J chain gene per haploid genome. This result was confirmed by quantitative analyses of band intensities yielded by Southern blots of mouse genomic DNA and J gene-containing plasmid DNA.

Animals↗
PubMed1981

Expression of the J chain gene during B cell differentiation is inversely correlated with DNA methylation.

During B cell differentiation, transcription of the J chain gene is initiated. To determine the regulatory mechanism involved, we have analyzed the structure of the J chain gene in cell lines representing successive stages in B cell development. Comparison of restriction sites showed that the J chain gene does not require a rearrangement of DNA for expression; cleavage sites present in embryonic J chain DNA were preserved through all the subsequent differentiative steps. However, comparison of 5-methylcytosine contents showed that J chain gene expression correlates with a loss of methyl groups. The J chain gene was heavily methylated in cell types not expressing J chain (i.e., embryo and lymphomas representative of immature and mature B cells) and significantly less methylated in cell lines representative of antigen-stimulated lymphocytes synthesizing J chain. These changes in J chain gene methylation represent a specific differentiation-induced response. Analyses of the heavy chain C mu and C gamma 2b genes, which are expressed at earlier and later stages than the J chain gene, showed that the C mu sequences were undermethylated in all cell types examined whereas the C gamma 2b sequences were undermethylated only in cell lines expressing the IgG2b protein. The primary encounter of a B cell with antigen must therefore trigger events that effect J chain gene transcription through a mechanism involving loss of methyl groups from cytosine.

5-Methylcytosine↗
PubMed1981

Correlation between the association and the desmutagenicity of benzo(a)pyrene by hemin: comparison with hemoproteins, transient metals and amines.

The mutagenicity of the potent carcinogen benzo(a)pyrene proved to be lost by binding with hemin and other tested compounds. The association constant (Kass) and the desmutation constant (Kmut) of benzo(a)pyrene and hemin were 8.5 x 10(4) M(-1) and 7.0 x 10(-4) M(-1), respectively. The correlation coefficient (gamma) of the association and the desmutation of benzo(a)pyrene and hemin was nearly 1, and the coefficient of regression of association on the desmutation, gamma (sigma ass/sigma mut), was 0.78. The correlation of other compounds, ferric chloride among transient metals, and 3,3'-diaminodipropylamine and p-phenylenediamine, were also almost 1 in both values, but their Kass an Kmut were must smaller than those of hemin: Kass:Kmut, 525 M(-1):520 M(-1) for ferric chloride, 2.2 x 10(3) M(-1):2.3 x 10(3) M(-1) for diaminodipropylamine and 175 M(-1):125 M(-1) for p-phenylenediamine. Good agreement of Kass and Kmut means that the desmutation of benzo(a)pyrene is caused by binding with tested materials.

Benzo(a)pyrene↗