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Biomedical subjects

Y Furutani

Publications and source records attributed to Y Furutani.

90 records · Page 5Linked to original sources
PubMed1984

Asynchronous left ventricular diastolic filling in patients with isolated disease of the left anterior descending coronary artery: assessment with radionuclide ventriculography.

To study the relationship between global and regional filling of the left ventricle, we conducted resting gated radionuclide ventriculographic studies in 15 control subjects (group 1) and 22 patients with isolated disease of the left anterior descending coronary artery (group 2). None had had a previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions. The time-activity and first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the normalized peak filling rate (PFR) was decreased (p less than .01) and the ratio of the time to PFR (time interval from global end-systole to PFR) to the diastolic time, TPFR/DT, was greater (p less than .02) in group 2 than in group 1. In the regional left ventricle, in the side perfused by the stenosed vessel (septal and apical), PFR was slightly decreased in the apical (p less than .05), but not the septal region (p = NS); TPFR/DT was greater in the apical (p less than .02) and in the septal region (p less than .01) in group 2. In the normally perfused lateral side, there were no significant differences in PFR or in TPFR/DT between group 1 and group 2. Total delta t/DT, which was defined as the ratio of the sum of the absolute values of the time differences from global PFR to regional PFR (septal, apical, and lateral) to the diastolic time, was significantly greater in group 2 (0.09 +/- 0.05 vs 0.16 +/- 0.05; p less than .001). This indicates the existence of asynchronous diastolic filling in the different regions of the left ventricle in group 2. A negative correlation existed between total delta t/DT and global PFR (r = -.64, p less than .001). Thus, in patients with one-vessel disease, asynchronous diastolic filling occurs due to the filling disturbance in the affected regions, which may cause impairment of the filling of the global left ventricle.

Adult↗
PubMed1984

Antitumor activity of deoxyribonucleic acid fraction from Mycobacterium bovis BCG. I. Isolation, physicochemical characterization, and antitumor activity.

A fraction extracted from Mycobacterium bovis strain BCG, which was composed of 70.0% DNA, 28.0% RNA, 1.3% protein, 0.20% glucose, and 0.1% lipid and of no detectable amounts of cell wall components such as alpha, epsilon-diaminopimelic acid and hexosamine, was found to possess strong antitumor activity. Repeated intralesional injection of this fraction, designated MY-1, without attachment to oil or a single intralesional injection of MY-1 emulsified in mineral oil caused the IMC carcinoma of CDF1 mice and line 10 tumor of strain 2 guinea pigs to regress and/or prevented metastasis very effectively. MY-1 after digestion with RNase, which contained 97.0% single-stranded DNA with a guanine-cytosine content of 69.8%, was more effective than undigested MY-1 against IMC and line 10 tumor, while MY-1 digested with DNase, which contained 97.0% RNA, had reduced activity, suggesting that the DNA from BCG possessed strong antitumor activity under certain conditions. Details of the extraction procedures and physicochemical characterization of MY-1 were also described.

Animals↗
PubMed1983

Structural homology of Torpedo californica acetylcholine receptor subunits.

The nicotinic acetylcholine receptor (AChR) from the electroplax of the ray Torpedo californica is composed of five subunits present in a molar stoichiometry of alpha 2 beta gamma delta (refs 1-3) and contains both the binding site for the neurotransmitter and the cation gating unit (reviewed in refs 4-6). We have recently elucidated the complete primary structures of the alpha-, beta- and delta-subunit precursors of the T. californica AChR by cloning and sequencing cDNAs for these polypeptides. Here, we report the whole primary structure of the gamma-subunit precursor of the AChR deduced from the nucleotide sequence of the cloned cDNA. Comparison of the amino acid sequences of the four subunits reveals marked homology among them. The close resemblance among the hydrophilicity profiles and predicted secondary structures of all the subunits suggests that these polypeptides are oriented in a pseudosymmetric fashion across the membrane. Each subunit contains four putative transmembrane segments that may be involved in the ionic channel. The transmembrane topology of the subunit molecules has also been inferred.

Amino Acid Sequence↗
PubMed1983

Cloning and sequence analysis of cDNA for ovine corticotropin-releasing factor precursor.

Previously, Guillemin and Rosenberg and Saffran and Schally demonstrated the presence of hypothalamic factors that stimulated the secretion of adrenocorticotropic hormone (ACTH) by the pituitary gland. Recently, Vale et al. have isolated and sequenced an ovine hypothalamic peptide of 41 amino acids, which is believed to represent the major physiological corticotropin-releasing factor (CRF) (reviewed in refs 5, 6). Available data suggest that hypothalamic CRF enhances both the synthesis and secretion of ACTH and related peptides such as beta-endorphin and beta-lipotropin (beta-LPH) (reviewed in ref. 6), which are all derived from the common precursor, termed ACTH-beta-LPH precursor or preproopiomelanocortin (reviewed in ref. 7). Because CRF mediates the neural control of the pituitary-adrenocortical system, the characterization of its biosynthetic precursor and the gene encoding it is essential for understanding the molecular mechanism underlying the endocrine response to stress. We have now cloned DNA sequences complementary to the ovine hypothalamic mRNA encoding the CRF precursor (referred to hereafter as prepro-CRF). The nucleotide sequence of the cloned cDNA, reported here, has revealed the primary structure of prepro-CRF. The carboxyl end represents the CRF sequence preceded by the tetrapeptide, Arg-Lys-Arg-Arg, and followed by the dipeptide, Gly-Lys. Comparison of the amino acid sequence of prepro-CRF with those of the ACTH-beta-LPH precursor and the arginine vasopressin-neurophysin II precursor suggests that these precursor proteins may be evolutionarily related.

Amino Acid Sequence↗
PubMed1983

Isolation and sequence analysis of the human corticotropin-releasing factor precursor gene.

A human genomic DNA segment containing the gene for the corticotropin-releasing factor precursor has been isolated by screening a gene library with an ovine cDNA probe. The cloned DNA segment has been subjected to restriction endonuclease mapping and nucleotide sequence analysis. Comparison of the nucleotide sequence of the gene with that of the ovine cDNA indicates that an intron of 800 bp is inserted in the segment encoding the 5'-untranslated region of the mRNA. The segment corresponding to the protein-coding and the 3'-untranslated region of the mRNA is uninterrupted. The mRNA and amino acid sequences of the human corticotropin-releasing factor precursor have been deduced from the corresponding gene sequence. The deduced amino acid sequence of human corticotropin-releasing factor exhibits seven amino acid substitutions in comparison with the ovine counterpart.

Amino Acid Sequence↗
PubMed1982

Primary structure of alpha-subunit precursor of Torpedo californica acetylcholine receptor deduced from cDNA sequence.

DNA sequences complementary to the Torpedo californica electroplax mRNA coding for the alpha-subunit precursor of the acetylcholine receptor were cloned. The nucleotide sequence of the cloned cDNA indicates that the precursor consists of 461 amino acids including a prepeptide of 24 amino acids. Possible sites for acetylcholine binding and antigenic determinants on the alpha-subunit molecule are discussed.

Amino Acid Sequence↗
PubMed1982

Cloning and sequence analysis of cDNA for porcine beta-neo-endorphin/dynorphin precursor.

The primary structure of a precursor protein that contains beta-neo-endorphin, dynorphin and a third leucine-enkephalin sequence with a carboxyl extension has been deduced from the nucleotide sequence of cloned DNA complementary to the porcine hypothalamic mRNA encoding it. The three peptides are each bounded by Lys-Arg. This precursor protein, like adrenal preproenkephalin and the corticotropin/beta-lipotropin precursor, comprises multiple repetitive units and a cysteine-containing amino-terminal sequence preceded by a signal peptide.

Amino Acid Sequence↗
PubMed1982

Cloning and sequence analysis of cDNA for bovine adrenal preproenkephalin.

The nucleotide sequence of cloned cDNA for preproenkephalin from bovine adrenal medulla indicates that the precursor protein contains four copies of Met-enkephalin and one copy each of Leu-enkephalin, Met-enkephalin-Arg6-Phe7 and Met-enkephalin-Arg6-Gly7-Leu8, a previously undetected opioid peptide. The enkephalin and extended enkephalin sequences are each bounded by paired basic amino acid residues. Preproenkephalin may represent a multi-hormone precursor, like the corticotropin-beta-lipotropin precursor.

Adrenal Glands↗
PubMed1981

New nalidixic acid resistance mutations related to deoxyribonucleic acid gyrase activity.

In Escherichia coli K-12 mutants which had a new nalidixic acid resistance mutation at about 82 min on the chromosome map, cell growth was resistant to or hypersusceptible to nalidixic acid, oxolinic acid, piromidic acid, pipemidic acid, and novobiocin. Deoxyribonucleic acid gyrase activity as tested by supercoiling of lambda phage deoxyribonucleic acid inside the mutants was similarly resistant or hypersusceptible to the compounds. The drug concentrations required for gyrase inhibition were much higher than those for cell growth inhibition but similar to those for inhibition of lambda phage multiplication. Transduction analysis with lambda phages carrying the chromosomal fragment of the tnaA-gyrB region suggested that one of the mutations, nal-31, was located on the gyrB gene.

Bacteriophage lambda↗
PubMedDate not supplied

Cloning and sequence analysis of calf cDNA and human genomic DNA encoding alpha-subunit precursor of muscle acetylcholine receptor.

The nicotinic acetylcholine receptor (AChR) from fish electric organ is well characterized and is known to consist of five subunits present in a molar stoichiometry of alpha 2 beta gamma delta (reviewed in refs 1-3). The mammalian skeletal muscle AChR is thought to have a similar subunit structure. We have recently elucidated the primary structures of the alpha-, beta-, gamma- and delta-subunit precursors of the Torpedo californica AChR by cloning and sequencing cDNAs for these polypeptides; cDNA sequences for the gamma-subunit precursor of the T. californica AChR and the alpha-subunit precursor of the Torpedo marmorata AChR have also been reported by other groups. The four subunits exhibit conspicuous sequence homology and are similar in hydrophilicity profile and predicted secondary structure, thus being most probably oriented in a pseudosymmetric fashion across the membrane. The transmembrane topology of the subunit molecules and the locations of functionally important regions, such as the acetylcholine binding site and the trans-membrane segments which may be involved in the ionic channel, have been proposed. We have now cloned cDNA for the alpha-subunit precursor of the calf skeletal muscle AChR and a human genomic DNA segment containing the corresponding gene. Nucleotide sequence analysis of the cloned DNAs has revealed the primary structures of the calf and human AChR alpha-subunit precursors, which exhibit marked sequence homology with their Torpedo counterpart. The protein-coding sequence of the human AChR alpha-subunit precursor gene is divided by eight introns into nine exons, which seem to correspond to different structural and functional domains of the subunit precursor molecule.

Animals↗
PubMedDate not supplied

Cloning, sequencing and expression of cDNA for a novel subunit of acetylcholine receptor from calf muscle.

The nicotinic acetylcholine receptor (AChR) from fish electric organ has a subunit structure of alpha 2 beta gamma delta, and this is thought to be also the case for the mammalian skeletal muscle AChR. By cloning and sequencing the complementary or genomic DNAs, we have previously elucidated the primary structures of all four subunits of the Torpedo californica electroplax and calf muscle AChR and of the alpha- and gamma-subunits of the human muscle AChR; the primary structures of the gamma-subunit of the T. californica AChR and the alpha-subunit of the Torpedo marmorata AChR have also been deduced elsewhere. We have now cloned DNA complementary to the calf muscle messenger RNA encoding a novel polypeptide (the epsilon-subunit) whose deduced amino-acid sequence has features characteristic of the AChR subunits and which shows higher sequence homology with the gamma-subunit than with the other subunits. cDNA expression studies indicate that the calf epsilon-subunit, as well as the calf gamma-subunit, can replace the Torpedo gamma-subunit to form the functional receptor in combination with the Torpedo alpha-, beta- and delta-subunits.

Amino Acid Sequence↗
PubMedDate not supplied

Molecular studies on interleukin-1 alpha.

When rabbit alveolar macrophages were treated with phorbol-12-myristate-13-acetate (PMA) and lipopolysaccharide (LPS), the synthesis of interleukin-1 (IL-1), as well as tumor necrosis factor (TNF), was greatly increased. These inducible cytokines were subjected to cloning by the differential colony hybridization method and the subsequent mRNA hybridization-translation assay. Cloned rabbit IL-1 cDNA was disclosed to encode the sequence of the counterpart of the mouse IL-1 alpha. This cDNA was used as a hybridization probe to screen a human cDNA library which was constructed from induced HL-60 cells, a human promyelocytic leukemia cell line. Isolated human IL-1 alpha cDNA was shown to direct the synthesis of a polypeptide with IL-1 activity in E. coli expression system. The chromosomal gene for human IL-1 alpha was isolated and characterized to elucidate the structural organization of this gene. To identify the region that is essential for regulating IL-1 alpha gene expression, various CAT (chloramphenicol acetyltransferase) fusion plasmids were constructed and analysed for their ability to direct CAT synthesis in a transient expression system. The unpublished results obtained in the early stages of these experiments are also presented and discussed in this review.

Animals↗