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M Fukuda

Publications and source records attributed to M Fukuda.

At least 1,171 records · Page 65Linked to original sources
PubMed1986

[Tissue CEA as a prognostic factor in advanced and recurrent breast cancers].

We stained tissue CEA in specimens of 25 advanced and reccurrenced breast cancers using the PAP method. We concluded the following: Tissue CEA positivity was 56.0% (14 out of 25 cases). Tissue CEA positivity was not correlated with age, clinical stage or histological type of primary breast cancer. Tissue CEA-positive breast cancers tended to have multiple distant metastases and very poor prognoses as opposed to negative ones.

Adult↗
PubMed1985

Mitochondrial DNA-like sequences in the human nuclear genome. Characterization and implications in the evolution of mitochondrial DNA.

Thirty-three phage clones carrying DNAs homologous to human mitochondrial DNA (mtDNA) were isolated from two independently constructed human gene libraries, and the region and extent of homology of mtDNA-like sequences carried by these clones were examined in hybridization experiments. Each phage clone contained DNA sequences homologous to various parts of the mtDNA and the extent of homology differed from clone to clone. From the efficiency of the library screening, it was estimated that human nuclear DNA contains at least several hundred copies of mtDNA-like fragments. Four clones carrying nuclear DNA sequences homologous to the mitochondrial Unidentified Reading Frame (URF) 4 and URF5 regions were chosen for further studies, and their structures were analyzed by DNA sequencing. Comparison of these mtDNA-like sequences with that of mtDNAs of several mammalian species revealed conservation of a part of the structures present in direct ancestral mtDNAs. The mtDNA fragments seem to have been continuously integrated into mammalian nuclear DNA during evolution.

Bacteriophage lambda↗
PubMed1985

Action of serine carboxypeptidases on endopeptidase substrates, peptide-4-methyl-coumaryl-7-amides.

Carboxypeptidase Y hydrolyzed N-substituted peptide-4-methylcoumarin-7-amides (peptide-NH-Mec) at pH 7 by releasing 7-amino-4-methylcoumarin (NH2-Mec) which was then followed by carboxypeptidase action. In particular, a chymotrypsin-directed substrate, Suc-Leu-Leu-Val-Tyr-NH-Mec, was hydrolyzed by the enzyme with a second-order rate constant of 7200 M-1 s-1, which is compatible with the rate for an anilide substrate and some N-substituted dipeptides. The activity was completely inhibited by phenylmethylsulfonyl fluoride and competitively depressed by the presence of an N-substituted dipeptide. Dependences of kinetic parameters on pH were different from those of carboxypeptidase, esterase, amidase, and anilidase activities. Carboxypeptidases P from Penicillium janthinellum and W from wheat also hydrolyzed some of these peptide-NH-Mec derivatives in a similar manner but at a rather low rate. Thus, the NH2-Mec-releasing activity may be considered to be intrinsic to serine carboxypeptidases in general. Taking into consideration this endopeptidase-like activity of serine carboxypeptidases, fluorogenic substrates should be used carefully to specify endopeptidases in crude extracts.

Amino Acids↗
PubMed1985

Structures of sialylated fucosyl polylactosaminoglycans isolated from chronic myelogenous leukemia cells.

Polylactosaminoglycans were isolated from human chronic myelogenous leukemia cells and their structures were elucidated. The lactosaminoglycan saccharides were isolated by hydrazinolysis and fractionated by QAE-Sephadex. The structures of fractionated oligosaccharides were analyzed by fast atom bombardment-mass spectrometry and methylation before and after treatment with specific exoglycosidases, such as alpha 2----3 specific neuraminidase. Based on these experiments, the structures of sialyl polylactosaminoglycans of chronic myelogenous leukemia cells were found to contain the following unique structure which is absent in normal mature granulocytes: (formula; see text) In addition to this, chronic myelogenous leukemia polylactosaminoglycans can be distinguished from normal granulocyte polylactosaminoglycans by the following characteristics. Leukemic polylactosaminoglycans are (a) shorter, (b) more highly sialylated and contain fully sialylated, tetrasialosyl polylactosaminoglycans, (c) are less fucosylated at C-3 of N-acetylglucosamine of polylactosaminyl side chains, and (d) contain a significant amount of sialyl Lex, NeuNAc alpha 2----3Gal beta 1----4(Fuc alpha 1----3)GlcNAc beta 1----3, structure. These results indicate that chronic myelogenous leukemia cells express unique polylactosaminoglycan structures which are distinct from normal mature granulocytes.

Amino Sugars↗
PubMed1985

Mechanism of carboxypeptidase-Y-catalyzed reaction deduced from a pressure-dependence study.

The activation volumes for kcat of the carboxypeptidase-Y-catalyzed hydrolysis of ester substrates were slightly negative (-1 to -4 ml/mol), while those for peptide and depsi-peptide analog were highly positive (+10 to +27 ml/mol). These values and the contrasting pH dependences of these two groups of the substrates are explained by a mechanism involving three ionic states of the enzyme and the second stable intermediate (acyl-enzyme). Esters are mostly rate-controlled by the deacylation step and peptides are controlled by both the acylation and the deacylation steps. Pressure increase induced a partial shift of the rate-determining step. Reaction volumes for Km-1 of peptide and depsi-peptide analog showed large and positive values (+16 to +29 ml/mol) which reflects the electrostatic interaction in the substrate recognition by this enzyme.

Carboxypeptidases↗
PubMed1985

Isolation of porcine follicular fluid inhibin of 32K daltons.

Purification of ovarian inhibin from porcine follicular fluid was performed by using an bioassay based upon the suppression of spontaneous FSH release from cultured cells of rat anterior pituitary. The presence in the follicular fluid of four molecular forms of inhibin activity corresponding to Mr 100K, 80K, 55K and 32K was revealed by SDS-gel electrophoresis under non-reducing conditions. The smallest inhibin amongst them, named 32K inhibin, eliciting about 70% of the total activity in the follicular fluid, was separated by gel filtration in the presence of 8 M urea. By subsequent ion-exchange chromatography, followed by RP-HPLC, 32K inhibin was purified to homogeneity with a 8,000 fold purification factor in a yield of 12%. The purified 32K inhibin was found to comprise two polypeptide subunits (Mr 20K and 13K), linked by disulfide bridges and to specifically suppress the secretion of FSH, but not of LH from the pituitary cells.

Animals↗
PubMed1985

Embryonal lactosaminoglycan. The structure of branched lactosaminoglycans with novel disialosyl (sialyl alpha 2----9 sialyl) terminals isolated from PA1 human embryonal carcinoma cells.

Lactosaminoglycan glycopeptides were isolated from human PA1 embryonal carcinoma cells and their structures were elucidated. The glycopeptides were digested by Escherichia freundii endo-beta-galactosidase before and after the modifications by exoglycosidases. The core glycopeptides and oligosaccharides thus obtained and the intact glycopeptides were analyzed by methylation, fast atom bombardment-mass spectrometry, and high-performance liquid chromatography. Based on these experiments, the structures of PA1 lactosaminoglycans were found to have the following unique features. 1) Three lactosaminoglycan fractions of different molecular weights were isolated by Sephadex G-50 gel filtration. Lactosaminoglycans of the highest molecular weight (GpI) have tetra-antennary cores, those of intermediate molecular weight (GpII) have triantennary cores and those of low molecular weight (GpIII) have triantennary and tetra-antennary cores. 2) GpI is composed of 22-26 lactosaminyl units and 7-9 branched galactose residues, GpII is composed of 16-22 lactosaminyl units and 5-7 branched galactose residues, and GpIII is composed of 12-16 lactosaminyl units and 3-4 branched galactose residues. 3) Each branch is short and is composed of the Gal beta 1----4GlcNAc beta 1----6 structure. 4) Sialic acid is preferentially linked to nonreducing terminal regions and a significant amount of the novel disialosyl structure, NeuNAc alpha 2----9NeuNAc alpha 2----3/6Gal, is present at the terminals of the longer polylactosaminyl side chains. 5) These lactosaminoglycans are carried by cell surface glycoproteins of Mr = 80,000 approximately 120,000, as evidenced by lectin-agarose chromatography.

Amino Sugars↗
PubMed1985

Monkey substantia nigra (pars reticulata) neuron discharges during operant feeding.

Unit activity in the substantia nigra pars reticulata was recorded during monkey bar-press feeding behavior. Activity of one-third of neurons was related to motor execution such as arm extension, flexion and bar-pressing, but not to motor preparation. Motor-related neurons were distributed mainly in the rostrolateral part of the nucleus. More than one-third responded during feeding and/or drinking acts and to intra- or perioral sensory stimuli. These ingestion-related neurons were distributed mainly in the caudomedial part of the nucleus.

Animals↗
PubMed1985

Structure of the carbohydrate units of human amniotic fluid fibronectin.

Human amniotic fluid fibronectin was found to contain three types of carbohydrates: complex-type N-glycosidic glycans, lactosaminoglycans, and O-glycosidic glycans. The structures of the complex-type glycans were established by carbohydrate and methylation analysis, Smith degradation, sequential exoglycosidase treatments, lectin chromatography, and DEAE-Sephadex chromatography. Lactosaminoglycans were analyzed by fast atom bombardment mass spectrometry, and the O-glycosidically-linked oligosaccharides by gas-liquid chromatography-mass spectrometry and high-pressure liquid chromatography. The results show that amniotic fluid fibronectin contains 2 mol of biantennary and 2-3 mol of triantennary, complex-type N-glycosidic glycans. Unlike the N-glycosidic glycans of human adult plasma fibronectin, which contain only traces of fucose and are completely sialylated, the glycans from amniotic fluid fibronectin are fucosylated and only partially sialylated. The complex-type N-glycosidic glycans present in amniotic fluid fibronectin also include a fractional amount (0.1 mol) of glycans with a polylactosaminyl structure. In addition, 4 mol of O-glycosidic oligosaccharides, which have not previously been described in fibronectins, were found in amniotic fluid fibronectin. The major oligosaccharides in this fraction have the structures Gal beta 1----3GalNAcol, NeuNAc alpha 2----3Gal beta 1----3GalNAcol and NeuNAc alpha 2----3Gal beta 1----3(NeuNAc alpha 2----6)GalNAcol. O-glycosidically linked oligosaccharides were also detected in human adult plasma fibronectin but in smaller amounts than in amniotic fluid fibronectin. These results show that amniotic fluid fibronectin differs from plasma fibronectin with regard to the number of glycans attached to the polypeptide and that the glycans present in these two fibronectins differ in structure.

Amniotic Fluid↗
PubMed1985

Evidence for a malarial parasite interaction site on the major transmembrane protein of the human erythrocyte.

Soluble oligosaccharides derived from the surface of human erythrocytes were tested for their ability to competitively inhibit invasion of erythrocytes by Plasmodium falciparum, a malarial parasite. Invasion was most effectively inhibited by erythroglycan, a carbohydrate component of the band 3 transmembrane protein. The lactosamine chains of erythroglycan contributed much of the inhibitory activity. This indication of a primary parasite interaction site on band 3 supports a role for this protein in mediating the radical alterations of the erythrocyte cytoskeleton that accompany invasion.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1985

Induction of cytoskeletal vimentin and actin gene expression by a tumor-promoting phorbol ester in the human leukemic cell line K562.

The tumor-promoting phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) was found to induce the biosynthesis and deposition of two cytoskeletal components in the human erythroleukemic cell line K562 with apparent Mr = 55,000 and 46,000. A time course showed that maximal changes in these cytoskeletal components occurred as early as 24 h after treatment and were maintained at least as long as 72 h. By immunoprecipitation, one of the induced cytoskeletal components was identified as vimentin. There was approximately a 10-fold induction of vimentin biosynthesis following TPA treatment. The other TPA-induced protein was found to co-migrate with purified actin in sodium dodecyl sulfate-polyacrylamide gels. Neither of these proteins was induced in the closely related human erythroleukemic cell line, HEL. By in vitro protein synthesis directed by total cellular RNA isolated from K562 cells, induction of vimentin biosynthesis was found to correlate with increases in the level of vimentin mRNA activity. A time course showed that vimentin mRNA activity was detectably elevated as early as 3 h after TPA treatment and reached a maximum by 12 h then the level decreased. By RNA dot blot and Northern gel hybridization using a cloned human actin cDNA, we found that there was also an induction of actin mRNA. A time course showed that there was an elevation of actin mRNA as early as 1 h after TPA treatment. The level then increased to a maximum at 6 h, after which the level decreased. These results are consistent with the induction of vimentin and actin gene transcription by TPA in K562 cells.

Actins↗
PubMed1985

Molecular structures of mitochondrial-DNA-like sequences in human nuclear DNA.

Two lambda phage clones carrying mitochondrial-DNA-like (mtDNA-like) sequences isolated from a human gene library were named Lm E-1 and Lm C-2, and their DNA structures were characterized. Lm E-1 contains about 0.4 kb DNA homologous to the 5' portion of the mitochondrial 16S ribosomal RNA (rRNA) gene and Lm C-2, a 1.6 kb DNA homologous to the 3' portion of the 12S rRNA gene and to almost all of the 16S rRNA gene. Comparisons of their nucleotide sequences with those of the corresponding regions of the human mtDNA revealed no detectable DNA rearrangement and their homologies to the human mtDNA are 84% and 80%, respectively. There are neither terminal repeats in the nuclear mtDNA-like sequences nor duplications of the nuclear DNAs flanking the mtDNA-like sequences. Evolutionary relationship between these two human nuclear mtDNA-like sequences and the human and bovine mtDNAs is discussed.

Animals↗