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Biomedical subjects

A Noda

Publications and source records attributed to A Noda.

At least 163 records · Page 9Linked to original sources
PubMed1986

Chemical studies of pancreatic nonopaque concretions and protein plug.

Chemical studies were performed on all or part of four X-ray translucent (nonopaque) concretions and one protein plug to investigate a possible relationship between these substances, and to find the similarities and differences between these materials and pancreatic stone protein. Through elemental analysis, infrared absorption spectrometry, quantitative analysis of protein, and amino acid analysis, nonopaque concretions and protein plug were found to consist mainly of protein. One nonopaque concretion contained a very small amount of crystalline which differed greatly from calcite type calcium carbonate as observed in pancreatic calcified stones. The pattern of amino acid composition was very similar between the concentrations and the protein plug: rich in acidic amino acids, but poor in basic and aromatic residues. The aspartic acid content was the highest among detected amino acids. Comparison of amino acid composition between the nonopaque concretions which we analyzed and the pancreatic stone protein reported from Sarles' laboratory suggested that the concretions seem to contain some stone protein.

Adult↗
PubMed1986

Comparative pharmacokinetic study of trimethadione and dimethadione for lysis of pancreatic stones.

In order to investigate the biological equivalence of dimethadione (DMO) and its precursor trimethadione (TMO), comparative pharmacokinetic studies were performed in 6 beagle dogs. DMO and TMO power was given orally at the same molar dose of 1.0 g and 1.11 g (7.7 mM), respectively. Plasma concentration of DMO and TMO was determined at an appropriate interval. Four pharmacokinetic parameters were calculated from the plasma concentration-time curves of DMO and TMO; the peak plasma concentration (Cmax), the time to the peak concentration of Cmax (Tmax), the area under the plasma concentration-time curve (AUC), and the biological half-life (t 1/2). In the plasma concentration-time curve of DMO, Tmax after oral administration of TMO was longer than that after administration of DMO. This resulted from the presence of the conversion process of TMO to DMO in the body, because of the very short Tmax observed in the plasma concentration-time curve of TMO. Cmax, AUC and t 1/2 did not differ significantly between the drugs. The results obtained indicate that TMO is biologically equivalent to DMO in regard to plasma concentration of DMO.

Administration, Oral↗
PubMed1986

Mutagenic and cytotoxic effects of oxygen free radicals generated by methylviologen (paraquat) on Escherichia coli with different DNA-repair capacities.

Investigations were carried out to examine the mutagenic and cytotoxic effects of oxygen free radicals on E. coli. E. coli B strains with different DNA-repair capacities were exposed to methyl viologen, commonly called paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride, MV), which has been shown to act as an intracellular generator of superoxide radicals. The results obtained were as follows: The cytotoxicity of MV in E. coli was dioxygen-dependent and due to the extent of intracellular generation of superoxide radicals. Cells containing higher levels of superoxide dismutase were more resistant to the toxic effect of MV. The cytotoxicity of MV was greater in DNA repair-deficient E. coli, Bs-1(exrA uvrB), NG30(recA) and R15(polA), than in DNA-repair-proficient strains (B/r and H/r30) and Hs30 (uvrB). MV was found to be mutagenic to E. coli H/r30 and Hs30 under aerobic conditions. The mutation frequencies to streptomycin resistance and to arginine prototrophy increased with the dose of MV in both strains. However, E. coli NG30 was unmutable by MV. The mutation induction did not occur under anaerobic conditions. The expression of the umu operon in E. coli was induced by MV under aerobic conditions. From these results, it was concluded that superoxide radicals intracellularly generated by MV include DNA damage, which causes cytotoxicity and mutation induction in E. coli, and that DNA damage induced by oxygen radicals is repairable by at least recA, polA and exrA(lexA) gene-controlled mechanisms.

DNA Repair↗
PubMed1986

Relationship between oxidative metabolites of hydrazine and hydrazine-induced mutagenicity.

Hydrazine (Hz) mutagenicity was observed in a test using Escherichia coli B/r strain, WP2 uvrA and was enhanced by the addition of rat liver microsomal fraction containing a generating system, while the enhanced mutagenicity was diminished by the addition of metyrapone to the microsome-free levels. On the other hand, an NADPH-dependent difference spectrum of the metabolic intermediate of Hz-complex, characterized by a maximum level of 448 nm, was also inhibited by metyrapone. The results show that the oxidative intermediates, which are diimide and its precursor, hydrazine free radical [Biochem. Biophys. Res. Commun., 133 (1986) 1086], are responsible not only for hepatotoxicity but also for the enhancement of genotoxicity or mutagenicity.

Animals↗
PubMed1986

Cerebral hemorrhagic infarction associated with anabolic steroid therapy for hypoplastic anemia.

A twenty-two-year-old student with hypoplastic anemia was treated with large doses of anabolic steroid hormone preparations for two months. Cerebral hemorrhagic infarction shown by CAT scan developed when his hematologic conditions were improving. In treating hypoplastic anemia with anabolic steroid hormone preparations, one should be aware of the possible development of cerebral hemorrhagic infarction at the time of hematologic improvement.

Adult↗
PubMed1986

Quantitative and qualitative characterization of human cancer-associated serum glycoprotein antigens expressing fucosyl or sialyl-fucosyl type 2 chain polylactosamine.

The quantity of tumor-associated antigens carrying type 2 chain polylactosamines with four types of fucosyl determinants, LeX (X-hapten), poly-LeX, sialyl LeX, and LeY (Y-hapten), present in sera of patients with various malignant and non-malignant disorders, as well as the qualitative chemical properties of the carrier molecules in sera, have been investigated using four monoclonal antibodies, each of which defines one of these determinants. The following findings are of particular importance: the serum levels of LeX defined by antibody FH2 and poly-LeX defined by ACFH18 in patients with cancer were occasionally high (incidence about 10%); however, the majority of patients did not show elevated levels; the serum level of the antigen, defined by monoclonal antibody FH6 (termed sialyl LeX-i since this determinant is carried by i antigen), was significantly high in patients with cancers originating from organs from which adenocarcinomas often develop. For example, among various types of lung cancer, only adenocarcinoma but not squamous cell carcinoma, small cell carcinoma, or large cell carcinoma showed a high level of sialyl LeX-i antigen in sera. The incidence of high antigen levels in sera of patients with adenocarcinomas of lung was as high as 76% of the observed cases; the serum level of Ley (Y-hapten) was frequently high in patients with hepatoma (incidence, 34%); sialyl LeX-i antigen was separated on gel filtration as a glycoprotein with an average molecular weight greater than 10(6). It was characterized by its susceptibility to basehydrolysis, Pronase digestion, and sialidase and endo-beta-galactosidase treatment and is assumed to be a high molecular weight mucin-type glycoprotein; sialyl LeX-i antigen expressed in sera of patients with cancer was soluble in perchloric acid, while the same antigen in sera of patients with noncancerous diseases and normal subjects was mostly insoluble in perchloric acid. LeX, a poly-LeX, and essentially all LeY antigens in sera of patients with cancer were perchloric acid-insoluble.

Antibodies, Monoclonal↗
PubMed1985

Spin trapping of a free radical intermediate formed during microsomal metabolism of hydrazine.

A radical formed during oxidative metabolism of hydrazine in rat liver microsomes was spin-trapped with alpha-phenyl-t-butylnitrone. The trapped species was identified as hydrazine radical by comparison of its ESR parameters and mass spectrum with those of the adduct formed during CuCl2 catalyzed oxidation of hydrazine. The requirement for oxygen and NADPH in the microsomal oxidation and the occurrence of a typical binding spectrum by difference spectroscopy suggest the involvement of the participation of the cytochrome P-450 enzyme system in the formation of hydrazine radical which must be a precursor of diimide during microsomal oxidation of hydrazine.

Animals↗
PubMed1985

Restriction fragment length polymorphism detected by human salivary amylase cDNA.

The plasmid clone which contains human salivary amylase cDNA was used to detect restriction fragment length polymorphisms (RFLPs). After double digestion with Pst 1 and Bam H1, a polymorphism with two alleles was observed. In Japanese, frequencies of these alleles, tentatively called 5.7 kb and 6.5 kb fragment alleles, are 0.55 and 0.45, respectively.

Alleles↗
PubMed1985

Effects of rifampicin and phenobarbital on the fate of isoniazid and hydrazine in vivo in rats.

After the intraperitoneal (i.p.) administration of isoniazid (INH) to male Wistar rats, the liver and plasma levels of hydrazine (Hz) and acetylhydrazine (AcHz), which are hazardous metabolites of INH and well known as mutagens, carcinogens and hepatotoxins, were determined by gas chromatography-mass spectrometry (GC-MS). The levels of Hz in rifampicin (RMP)- or phenobarbital (PB)-pretreated groups were lower than those in the control group, while the amount of AcHz was scarcely altered. In each of the pretreated groups a pronounced increase in the oxidative elimination rate of Hz was observed. These results are of important toxicological significance in INH therapy with RMP, since an active intermediate of Hz seems to be a hepatotoxin.

Acetylation↗
PubMed1985

Product inhibition of aminopyrine N-demethylation in isolated hepatocytes.

The product inhibition of aminopyrine (AM) N-demethylation by 4-monomethylaminoantipyrine (MAA) was examined in vitro in preparations of isolated rat hepatocytes using gas chromatograph-mass spectrometer (GC-MS). The kinetic study for AM N-demethylation, which was determined by MAA formation, was studied at concentrations from 0.2 to 4.0 mM with or without various concentrations of D3-MAA. D3-MAA inhibited AM N-demethylation non-competitively at concentrations of 0.2 to 1.0 mM of AM (Ki = 0.81 mM), though it did competitively at concentrations of 1.0 to 4.0 mM of AM (Ki = 0.81 mM). From the present observation, it was suggested that the inhibition type of AM N-demethylation by D3-MAA was dependent on the substrate (AM) concentration.

Aminopyrine↗
PubMed1985

Pancreatic A- and B-cell responses to intravenous arginine in cancer of the head of the pancreas: relation to clinical features.

The endocrine pancreatic functions were evaluated in 19 patients with pancreatic head cancer by measuring plasma immunoreactive pancreatic glucagon (IRG) and insulin (IRI) responses to an intravenous dose of 30 g of arginine. The IRG responses differed by level of urinary amylase excretion, degree of glucose intolerance and degree of exocrine insufficiency. Higher IRG responses were observed in the nondiabetic subset, the hyperamylasuric subset, and the mild to moderate exocrine insufficient subset than in the corresponding opposites. Even higher responses were also found in the subset with all 3 characteristics, suggesting better preservation of the pancreatic tissue, than in that with 2 or fewer. The results obtained suggest that A-cell function increases in the earlier stages of pancreatic head cancer.

Amylases↗