Search PubMed⌕ Search

Biomedical subjects

A Shiozawa

Publications and source records attributed to A Shiozawa.

14 recordsLinked to original sources
PubMed2000

Characterization of reactive oxygen species generated from the mixture of NaClO and H2O2 used as root canal irrigants.

Characterization of a mixed solution of sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2), which have been used as root canal irrigants, was investigated using electron spin resonance spectroscopy combined with a spin-trapping technique. In the solution, two kinds of reactive oxygen species, the superoxide anion radical (O2-.) and the hydroxyl radical (.OH), were detected. The pH changes and dissolved oxygen values in the NaClO-H2O2 reaction mixture were investigated. The pH influenced the generation of O2-. and .OH, and O2 was generated from H2O2. It is suggested that root canal irrigation with NaClO and H2O2 induces biological effects, such as tissue irritation (from the chemical reactions of O2-. and .OH) and physical effects, such as O2 bubbling.

Electron Spin Resonance Spectroscopy↗
PubMed1999

Prognostic significance of bcl-2 expression in leiomyosarcoma of the uterus.

We examined bcl-2 expression as well as p53 expression and mutation in human uterine smooth muscle tumours to determine the influence of bcl-2 expression on prognosis in patients with uterine leiomyosarcomas. bcl-2 protein was expressed in nearly all benign smooth muscle tumours but in only 57% of leiomyosarcomas. Benign smooth muscle tumours were usually negative for p53 protein, but 16 out of 21 (76%) leiomyosarcomas were positive. A p53 gene mutation was detected in nine of the 16 leiomyosarcomas that showed p53-positive staining. A significant positive correlation was observed between p53 mutation and p53 expression, between the number of mitoses and the Ki-67 labelling index, and between clinical stage and p53 mutation. A significant negative correlation was observed between bcl-2 expression and p53 mutation, and between bcl-2 expression and p53 overexpression. Univariate survival analysis revealed that bcl-2 expression, p53 mutation and clinical stage (stage 1 vs stages 2-4) all showed a significant correlation with prognosis. In a multivariate stepwise regression analysis, positive bcl-2 expression and stage 1 disease were the independent predictors of a favourable prognosis. Our results suggest that bcl-2 is frequently expressed in human uterine smooth muscle tumours, and that its expression may correlate with a favourable prognosis in patients with uterine leiomyosarcoma.

Adult↗
PubMed1998

Effect of nonsteroidal anti-inflammatory drugs on lipid peroxidation by hydroxyl radical.

1. Effects of acetaminophen and sodium salicylate on hydoxyl radical elimination were studied using an electron-spin-resonance spin-trapping method. The effects of these agents on lipid peroxidation of the human erythrocyte membrane were also investigated by the thiobarbituric acid method. 2. Acetaminophen and sodium salicylate depressed hydroxyl radical generated by Cu2+/H2O2. 3. Acetaminophen inhibited Cu2+/H2O2-dependent lipid peroxidation; however, sodium salicylate enhanced Cu2+/H2O2-dependent lipid peroxidation.

Acetaminophen↗
PubMed1996

Forskolin derivatives. I. Synthesis, and cardiovascular and adenylate cyclase-stimulating activities of water-soluble forskolins.

Water-soluble forskolin and 7-deacetylforskolin derivatives with an aminoacetyl, a 3-aminopropionyl, or a 4-aminobutyryl group at the 6- or 7-position were prepared, and their positive inotropic as well as vasodilative activities were evaluated in anesthetized dogs. 7-Deacetylforskolin (2) and 7-deacetyl-1-silylforskolin (6) were converted to the corresponding 7-chloroacylderivatives (3, 7, 10), which were reacted with amines to obtain 7-aminoacyl-7-deacetylforskolins (4a-f, 9a, b, 11). The 7-acyl substituents migrated to the 6-position with sodium hydroxide in acetonitrile-water to afford 6-aminoacyl-7-deacetylforskolins (12a-f). The 7-position of 12a, d-f was selectively acetylated with acetyl chloride to obtain the corresponding 6-aminoacylforskolins (13a-d). Among the 6-aminoacylforskolins, 6-(3-dimethylaminopropionyl)forskolin (13b) and 6-(4-dimethylaminobutyryl)forskolin (13d) exhibited potent positive inotropic and vasodilative activities comparable to those of forskolin (1). The activities of 13b and 13d were approximately ten times more potent than those of 7-aminoacyl- and 6-aminoacyl-7-deacetylforskolins (4a-f, 9a, 12a-c, f). 6-Dimethylaminoacetylforskolin (13a) and 6-(3-diethylaminopropionyl)forskolin (13c) were less potent than 1. The effects of the soluble forskolins on adenylate cyclase activity were also examined in vitro. 6-Aminoacylforskolins (13a-d) exhibited potent adenylate cyclase-stimulating activity, comparable to that of 1.

Adenylyl Cyclases↗
PubMed1987

[Bilateral renal cell carcinoma associated with von Hippel-Lindau disease].

A 52-year-old man was referred to the department of neurosurgery of our hospital for evaluation of left occipital pain on September 27, 1982. Brain CT and arteriography showed midcerebellar tumor and an operation was performed on October 7, 1982. Histopathologically, the tumor was hemangioblastoma (solid type). His whole-body CT showed bilateral multiple renal tumors but no angioma retinae were found. Angiography revealed that the lesions were bilateral multiple (more than 20) renal tumors, bilateral adrenal tumors and left retroaortic renal vein. The patient underwent bilateral radical nephrectomy and lymphadenectomy on December 15, 1982. Renal cell carcinoma (grade II greater than III) with adrenal and left renal vein involvement were noted on the pathologic specimen. Postoperatively, he received supplement therapy with hydrocortisone and hemodialysis, but died of bleeding from the recurrent hemangioblastoma on July 7, 1983.

Angiomatosis↗