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S Fukui

Publications and source records attributed to S Fukui.

At least 163 records · Page 9Linked to original sources
PubMed1987

Expression of keratins during experimentally induced carcinogenesis in hamster cheek pouch visualized polyclonal and monoclonal antibodies.

We obtained immunohistochemical profiles of several keratin proteins during experimentally induced carcinogenesis in hamster cheek-pouch mucosa using a polyclonal antibody (TK; detecting keratins with molecular masses of 41-65 kilodalton) and two monoclonal antibodies (KL1, 55- to 57-kilodalton keratins; PKK1; 40-, 45- and 52.5-kilodalton keratins). The squamous epithelium of normal pouch mucosa exhibited positive TK staining in all layers, KL1 staining in the spinous layer and PKK1 staining in the basal layer, thus indicating a regional or zonal distribution pattern. Epithelia undergoing basal hyperplasia showed irregular localization of PKK1 binding, while hyperkeratinized lesions exhibited the binding pattern found in normal epithelium. In case of epithelial dysplasia, there was reduced KL1 staining in spinous cells and decreased PKK1 staining in the basal and parabasal layers. Papillomas exhibited a rather zonal distribution of keratin staining. All squamous-cell carcinomas, irrespective of their degree of keratinization and infiltration pattern, showed slight or no PKK1 staining. Such lesions were only positive for KL1-detectable keratins in keratinizing tumour cells and exhibited an irregular distribution of TK binding. The expression of keratin proteins during carcinogenesis in hamster cheek-pouch mucosa may parallel that of keratins in human squamous-cell carcinomas originating in the oral mucosa.

Animals↗
PubMed1987

Mutagenicity-enhancing effect of quercetin on the active metabolites of 2-acetylaminofluorene with mammalian metabolic activation systems.

The effects of quercetin on the mutagenicity of 2-acetylaminofluorene (AAF) and its 3 active metabolites, N-hydroxy-AAF (N-OH-AAF), aminofluorene (AF) and N-acetoxy-AAF(N-OAc-AAF) were investigated. The mutagenicity assays were carried out with Salmonella typhimurium TA98, and S9, microsomes and cytosol were used as metabolic activation systems. In the presence of S9, quercetin enhanced the mutagenicity of AAF, N-OH-AAF, AF and N-OAc-AAF by 6.9-, 4.3-, 3.6- and 3.9-fold, respectively. Quercetin enhanced the mutagenicity of these substrates with microsomes, whereas it depressed the mutagenicity of these substrates with cytosol. From these results, it seemed probable that quercetin promotes the N-hydroxylation and deacetylation in the microsomes, whereas it inhibits the deacetylation in the cytosol. It was shown that in the metabolism of AAF and its metabolites, quercetin modulates the balance between the mutagenicity activation and inactivation processes, which is catalysed by the enzymes in the microsomes and cytosol, and causes enhancement of the mutagenicity of AAF.

2-Acetylaminofluorene↗
PubMed1987

Enhancement of the mutagenicity of 2-acetylaminofluorene by flavonoids and the structural requirements.

The enhancing effects of 12 kinds of flavonoids on the mutagenicity of 2-acetylaminofluorene (AAF) in Salmonella typhimurium TA98 were investigated. In the mixed applications of AAF (22.4 nmoles/plate) with flavonoids (31.4-45.0 nmoles/plate) in the presence of a mammalian metabolic activation system (S9 mix), morin, galangin, flavonol, kaempferol, quercetin and myricetin enhanced the mutagenicity of AAF by 3.3-10.2-fold. The potency of the mutagenicity enhancing effects increased in the described order. For the mutagenicity-enhancing effects of the flavonoids on AAF, the flavonol structure, including the free 3-hydroxyl group and the 2,3-double bond, were essential. In the quercetin analogues, the 5-hydroxyl group was also essential. Further, the numbers of the hydroxyl groups substituted at the 3', 4' and 5'-positions in the B-ring contributed to an increase of the enhancing effect, whereas the substitution of a hydroxyl group at the 2'-position depressed the potency of the effect.

2-Acetylaminofluorene↗
PubMed1987

2,7-Diamino-3,8-dimethylphenazine as the major mutagenic product from the reaction of 2,4-diaminotoluene with hydrogen peroxide.

The mutagenicity of 2,4-diaminotoluene (DAT) in Ames's Salmonella/microsome test was remarkably enhanced by treatment with hydrogen peroxide. Therefore, identification of the major mutagenic reaction product of 2,4-DAT with hydrogen peroxide at room temperature has been performed. Red precipitates were produced in a 2-day reaction mixture and were column chromatographed on silica gel. 5 fractions having mutagenic potency were obtained. The red crystalline needles, obtained as the major reaction product, were separated from fraction 2 and were subjected to high resolution mass spectrometry, 1H- and 13C-NMR spectrometry. The structure of the compound was determined to be 2,7-diamino-3,8-dimethylphenazine from physicochemical and chemical evidence. The compound induced 212 revertants/nmole in Salmonella typhimurium TA98 with 25 microliters S9 per plate.

Animals↗
PubMed1987

Mutagenicity modulating effect of quercetin on aromatic amines and acetamides.

The effect of quercetin on the mutagenicity of 32 kinds of aromatic amines and their acetamides were investigated using Salmonella typhimurium TA98 with a mammalian metabolic activation system (S9 mix). Quercetin enhanced the mutagenicity of the tricyclic aromatic amines (aminofluorene, aminoanthracene and aminophenanthrene) and their acetamides by 1.2-5.9-fold. Whereas, quercetin depressed the mutagenicity of aniline derivatives, biphenyl derivatives, and bi- and tetra-cyclic amino derivatives. The modulation of mutagenicity of Trp-P-1, Trp-P-2, Glu-P-1 and Glu-P-2 (heterocyclic amines) by quercetin were liable to be affected by the content of S9 in the S9 mix. It seems that quercetin does not have the same effect as norharman, because quercetin did not enhance the mutagenicity of aniline. It is suggested that the modulation of the mutagenicity of aromatic amines and acetamides is caused by the modulation of the balance between the mutagenic activation and inactivation in the metabolism of these amines and acetamides in the presence of quercetin. In this modulation, quercetin may participate through its effects on the promotion of N-hydroxylation and the inhibition of arylhydroxylation and transacylation. The presence of tricyclic aromatic rings of amines and acetamides is a structural requirement for the mutagenicity enhancement by quercetin.

Amides↗
PubMed1987

Mutagenic reactivities of 3,4-dinitrobiphenyl derivatives.

3,4-Dinitrobiphenyl derivatives were mutagenic in Salmonella typhimurium TA98, TA98/1,8-DNP6 and in TA98NR. We describe here the specific reactivity of 3,4-dinitrobiphenyl derivatives with diluted sodium hydroxide solution and the determination of the amounts of released nitrous ion. 3,4-Dinitrobiphenyl derivatives begin to release nitrous ions when treated with NaOH solution at a concentration of 10(-3) N. The behavior of 4NQO and o-dinitrobenzene was the same as that of 3,4-dinitrobiphenyl derivatives. The residues of 3,4-dinitrobiphenyl derivatives, after releasing nitrous ions, were estimated to be hydroxy-nitrobiphenyls, as by GC/MS, we found the formation of o-nitrophenol in the reaction mixture of o-dinitrobenzene with aqueous NaOH solution. 3,4,4'-Trinitrobiphenyl, 3,4,3',4'-tetranitrobiphenyl and 4NQO had reduced mutagenic potency in Salmonella typhimurium TA98 following treatment with diluted NaOH. In order to elucidate the ultimate forms of 3,4-dinitrobiphenyl derivatives, we investigated the reaction of o-dinitrobenzene as a basic model substance of 3,4-dinitrobiphenyl, with nucleic bases in the presence of NaOH in nonaqueous solvent. o-Nitrophenyl guanine and adenine adducts were obtained.

Dinitrobenzenes↗
PubMed1987

Peroxisomal acyl-coenzyme A oxidase multigene family of the yeast Candida tropicalis; nucleotide sequence of a third gene and its protein product.

We have determined the complete nucleotide sequence of gene POX2, which encodes one of the major peroxisomal polypeptides (PXPs) of Candida tropicalis. POX2 is linked to gene POX4, which codes for a subunit (PXP-4) of long-chain acyl-CoA oxidase. Southern blot analysis revealed that POX2 had a significant homology to POX4, and also to gene POX5 which encodes a subunit (PXP-5) of the isozyme of acyl-CoA oxidase. PXP-2, the protein product of POX2, was co-purified with PXP-4 from the isolated peroxisomes. PXP-2 itself was a flavoprotein and likely to form an equimolar complex with PXP-4, although its enzymatic activity was uncertain. POX2 corresponds to a single open reading frame of 724 amino acids and has no introns. The N-terminal sequence and the calculated Mr of the deduced polypeptide were consistent with those of isolated PXP-2. The primary structure was highly homologous to those of PXP-4 and PXP-5 in respect of the amino acid sequence and the hydropathy profile. We conclude that POX2 is a third gene of the peroxisomal acyl-COA oxidase multigene family.

Acyl-CoA Oxidase↗
PubMed1987

Correlative studies on changes in lipid composition of gills and uptake of chemicals of willow shiner fish (Gnathopogon caerulescens) by exposure to detergent.

One group of willow shiner (Gnathopogon caerulescens) was exposed to 0.1 mg/l dodecylbenzenesulfonate (DBS) for analysis of lipid composition of gill extracts. Another group of fish was exposed to 0.0003 mg/l 2,4,6-trichlorophenyl-4'-nitrophenyl-ether (CNP) after regular intervals of pre-exposure to 0.1 mg/l DBS for analysis of uptake of CNP. The whole body residues of CNP were characterized by a 60% drop in DBS pre-exposure for 14 and 21 days. The cholesterol/total phospholipid ratio increased to 0.22 and 0.28 after 14 and 21 days from the normal of 0.18. These biochemical results might be correlated with the changes observed by the uptake of CNP.

Animals↗
PubMed1987

Comparative studies on additive effects of sodium dodecylbenzensulfonate and sodium stearate on uptake of chemicals by willow shiner (Gnathopogon caerulescens).

Comparative studies between sodium dodecylbenzensulfonate (DBS) and sodium stearate (SNa) were performed on the additive effects of the uptake of chemicals in a fresh water fish, the willow shiner (Gnathopogon caerulescens), by the use of a continuous flow water system. The chemicals selected were 2,4,6-trichlorophenyl-4'-nitrophenyl ether (CNP) as a non-polar lipophilic substance and cadmium salt (Cd) as polar hydrophilic substance. DBS had no promotive and depressive effects on the uptake of Cd. SNa had no promotive and depressed effects on the uptake of CNP and Cd.

Animals↗
PubMed1987

Prostaglandin E1 in pulmonary hypertension of collagen disease.

A 47-yr-old woman with low cardiac output and dyspnea due to pulmonary hypertension associated with rheumatoid arthritis was treated with two vasodilators. Although nicardipine, a Ca-channel blocking agent, reduced the pulmonary artery pressure (PAP), it reduced simultaneously the arterial BP, resulting in fluid retention with a low urine output and persistent high CVP. In contrast, prostaglandin E1 (PGE1) reduced successfully both the PAP and CVP. Although the BP decreased, a satisfactory urine output was maintained. The cardiac output increased from 3 to 4.5 L/min. PGE1 may help reduce reversible pulmonary hypertension of collagen disease.

Alprostadil↗
PubMed1987

Purification and characterization of a Ca2+-dependent membrane peptidase involved in the signaling of mating pheromone in Rhodosporidium toruloides.

A mating-type-specific, membrane thiol peptidase (referred to as trigger peptidase) that seems to play a key role in the transmembrane signaling of the lipopeptidyl mating pheromone rhodotorucine A at the cell surface of mating type a cells of Rhodosporidium toruloides (T. Miyakawa, M. Kaji, T. Yasutake, Y.K. Jeong, E. Tsuchiya, and S. Fukui, J. Bacteriol. 162:294-299, 1985) was purified to homogeneity and characterized. The following lines of evidence support the contention that the enzyme we purified was the trigger peptidase: the identical specificity of hydrolysis at the Arg-Asn sequence of rhodotorucine A and the sensitivity of the reaction to sulfhydryl-blocking reagents; the identical specificity for the substrate, with a strict requirement for the presence of the lipid moiety; and the absence of the corresponding activity in the pheromone-producing strain (mating type A) and in a sterile mutant strain, M-39 (type a), that lacks trigger peptidase activity in vivo. The apparent molecular weight of trigger peptidase was estimated to be 68,000 by Sepharose 6B gel filtration in the presence of octylglucoside and 63,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Trigger peptidase alone was inactive but exhibited enzymatic activity with the simultaneous addition of Ca2+, membrane phospholipids, and a nonionic detergent such as octylglucoside. The concentration of Ca2+ required for maximum activation was approximately 1 mM. Only Mn2+ could replace Ca2+ at comparable concentrations. Among the phospholipids tested, only phosphatidylserine and phosphatidylethanolamine supported trigger peptidase activation. Solubilized trigger peptidase was strongly inhibited by antipain and phosphoramidon.

Basidiomycota↗
PubMed1987

Gene fusion is a possible mechanism underlying the evolution of STA1.

DNA from the STA1 (extracellular glucoamylase) gene of Saccharomyces diastaticus was used as a probe to enable the cloning by colony hybridization of three DNA fragments from Saccharomyces cerevisiae; these were designated S1, S2, and SGA (intracellular, sporulation-specific glucoamylase gene). To examine the evolutionary relationship among these sequences at the nucleotide level, we sequenced S2, S1, SGA and compared them with STA1. These data and RNA blot analysis revealed that the following regions of STA1 were highly conserved in S2, S1, and SGA: upstream regulatory sequences responsible for transcription, a signal sequence for protein secretion, a threonine- and serine-rich domain, and a catalytic domain for glucoamylase activity. These results suggest that an ancestral STA gene was generated relatively recently in an evolutionary time scale by the sequential fusions of S2, S1, and SGA, with S1 functioning as a connector for S2 and SGA. We describe a model for the involvement of short nucleotide sequences flanking the junctions in the gene fusions.

Amino Acid Sequence↗
PubMed1987

Nucleotide sequence of the glucoamylase gene GLU1 in the yeast Saccharomycopsis fibuligera.

The complete nucleotide sequence of the glucoamylase gene GLU1 from the yeast Saccharomycopsis fibuligera has been determined. The GLU1 DNA hybridized to a polyadenylated RNA of 2.1 kilobases. A single open reading frame codes for a 519-amino-acid protein which contains four potential N-glycosylation sites. The putative precursor begins with a hydrophobic segment that presumably acts as a signal sequence for secretion. Glucoamylase was purified from a culture fluid of the yeast Saccharomyces cerevisiae which had been transformed with a plasmid carrying GLU1. The molecular weight of the protein was 57,000 by both gel filtration and acrylamide gel electrophoresis. The protein was glycosylated with asparagine-linked glycosides whose molecular weight was 2,000. The amino-terminal sequence of the protein began from the 28th amino acid residue from the first methionine of the putative precursor. The amino acid composition of the purified protein matched the predicted amino acid composition. These results confirmed that GLU1 encodes glucoamylase. A comparison of the amino acid sequence of glucoamylases from several fungi and yeast shows five highly conserved regions. One homology region is absent from the yeast enzyme and so may not be essential to glucoamylase function.

Amino Acid Sequence↗
PubMed1987

Immediate and long-term prognoses of acute myocardial infarction: analysis of determinants of prognosis.

In order to investigate the immediate and long-term prognoses of acute myocardial infarction, we followed up 790 consecutive patients who were admitted to the Sakurabashi Watanabe Hospital within 24 hours after the onset of infarction from January 1975 to December 1984 and evaluated early mortality, cumulative survival rate after discharge, cause of death and occurrence of recurrent myocardial infarction during follow-up. Early mortality (within 30 days after the onset) in all patients was 17.6% and declined serially in the most recent five years. Pump failure was the most common cause of death, followed by cardiac rupture and arrhythmias. Age, gender (female), presence of a previous infarct and anterior infarction were important contributing factors to the immediate prognosis. One hundred and thirty-five of the 651 patients who survived one month after the onset of infarct died during the follow-up period (mean follow-up interval: 41.0 +/- 29.9 (SD) months). Cumulative survival rates calculated by the life-table method at one and 5 years after the onset were 91.0% and 76.0%, respectively, and the average annual mortality in the first 5 years was 4.8%. Age and reinfarction were the important determining factors of long-term prognosis. Recurrent myocardial infarction, pump failure and sudden cardiac death were common causes of late death. One hundred and two reinfarctions in 93 patients occurred during the follow-up period. Thirty-two of 93 patients (34.4%) died due to fatal reinfarction. These results indicate that the immediate prognosis of acute myocardial infarction has improved serially, but the long-term prognosis is still poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗