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Biomedical subjects

T Miyata

Publications and source records attributed to T Miyata.

At least 595 records · Page 33Linked to original sources

Ischemic colitis in a 33-year-old woman on danazol treatment for endometriosis.

A 33-yr-old Japanese woman, married, no parity, was treated for endometriosis. Danazol 400 mg a day was initiated on September 25, 1986, for 21 consecutive days. She became severely constipated and had left lower abdominal colic pain. Five days later, she had to be admitted to the hospital, because she had had no bowel movements for 12 days and the abdominal pain was severe. On the day after admission, she had frequent painful bowel movements. The stool was blood-tinged, but pathogenic bacteria were nil. Ischemic colitis of the stricture type was identified. She was treated with hyperalimentation and anticholinergic agents. At 3 months and 5 days after discharge from hospital, danazol 400 mg per day was readministered, and 11 days later, the patient again became constipated and complained of the same pain in the left flank. We consider that danazol-induced constipation played a role in the onset of the ischemic colitis.

Adult↗

General pharmacological studies on N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate. 1st communication: effect on the central nervous system.

The pharmacological actions of N-(2,6-dimethylphenyl)-8-pyrrolizidineacetamide hydrochloride hemihydrate (SUN 1165), a new antiarrhythmic agent, on the central nervous system were studied in various experimental animals as compared with those of disopyramide, mexiletine and lidocaine, and the following results were obtained. 1. Acute toxicity of SUN 1165 in mice was similar to that of mexiletine, and twice as potent as compared with that of disopyramide and lidocaine. Main acute toxic symptoms of SUN 1165 were muscle relaxation, ataxia, clonic convulsions, tremor and a decrease in spontaneous activity in mice, rats and rabbits. In addition to these symptoms, vomiting in dogs was observed. These toxic symptoms were similar to those of lidocaine. In the case of disopyramide, ataxia, tremor and a decrease in spontaneous activity were observed in mice and rats. On the other hand, mexiletine caused central nervous excitatory symptoms, that is, tremor, Straub tail, clonic convulsions, jumping, running and opisthotonus in mice and rats, and vomiting in dogs. 2. SUN 1165 even at large doses (50-100 mg/kg p.o.) exerted no significant effects on the following changes: hexobarbital-induced induced hypnosis, oxotremorine-induced tremor, apomorphine-induced hypothermia, reserpine-induced ptosis and hypothermia, 5-hydroxytryptophan syndrome and fighting behavior in mice, and conditioned avoidance response in rats. 3. An ineffective dose of SUN 1165 (12.5 mg/kg p.o.) on spontaneous locomotor activity was lower than of disopyramide and lidocaine, however, higher than that of mexiletine. 4. SUN 1165 at large doses showed antagonistic action on toxic extensor seizures induced by maximal electroshock, picrotoxin, or strychnine in mice, but anticonvulsive effects of SUN 1165 were less potent than those of mexiletine and lidocaine. SUN 1165 had no effect on clonic convulsions induced by pentetrazol and pictrotoxin in mice, while both mexiletine and lidocaine prolonged the duration of clonic convulsions. 5. The muscle relaxant effect of SUN 1165 (50%-toxic dose, TD50 = 30 mg/kg p.o.) was more marked than that of lidocaine (TD50 = 92 mg/kg p.o.) on traction test in mice. However, effect of SUN 1165 (TD50 = 62 mg/kg p.o.) on motor incoordination was similar to that of disopyramide, mexiletine and lidocaine on the rotarod test in mice. 6. The analgesic effect of SUN 1165 was as weak as that of disopyramide, mexiletine and lidocaine on chemically and mechanically-induced pain response in mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

[Prevention of immunodeficiency induced by cancer chemotherapy with BCG].

MFC (MMC, 5-FU and cytosine-arabinoside) therapy applied with the liver organism Bacillus Calmette-Guérin (BCG) for the treatment of postoperative patients with cancer of the digestive organs presenting at stage II and III. Immunological parameters included skin reaction by purified protein derivative (PPD), lymphatic blastogenesis test using phytohemagglutinin (PHA) and lymphatic subsets. The frequency of MFC therapy was significantly higher in the MFC plus BCG group than in the MFC group (p less than 0.001). At the completion of MFC therapy, both of PHA blastogenesis rate, OKT4/OKT8 and OKT3 were all within the normal limits. The PPD skin reaction was positive (18.2 +/- 4.0mm) as before the start of MFC therapy. These results suggest that BCG immunotherapy may potentiate the effect of chemotherapy.

Aged↗

Complementary DNA for the mouse homolog of the human amyloid beta protein precursor.

The human amyloid beta protein is a major component of brain amyloid found in patients with Alzheimer's disease. As an initial step to understand the biological function of its precursor protein, we have isolated cDNA for the mouse homolog of the human beta protein precursor. Comparison of the predicted amino acid sequence with that of human revealed a quite high degree of homology (96.8%), and the calculated evolutionary rate of the mRNA at amino acid substitution site was relatively low (0.1 x 10(-9)/site/year). The mRNA was abundant in brain and kidney, and also detected in other tissues at low level. These results indicated that this protein is highly conserved through mammalian evolution and may be involved in a basic biological process(es).

Amino Acid Sequence↗

Lipopolysaccharide-sensitive serine-protease zymogen (factor C) of horseshoe crab hemocytes. Identification and alignment of proteolytic fragments produced during the activation show that it is a novel type of serine protease.

The horseshoe crab clotting factor, factor C, present in the hemocytes is a serine-protease zymogen activated with lipopolysaccharide. It is a two-chain glycoprotein (Mr = 123,000) composed of a heavy chain (Mr = 80,000) and a light chain (Mr = 43,000) [T. Nakamura et al. (1986) Eur. J. Biochem. 154, 511-521]. In our continued study of this zymogen, we have now also found a single-chain form of factor C (Mr = 123,000) in the hemocyte lysate. The heavy chain had the NH2-terminal sequence of Ser-Gly-Val-Asp-, consistent with that of the single-chain factor C, indicating that the heavy chain is derived from the NH2-terminal part of the molecule. The light chain had an NH2-terminal sequence of Ser-Ser-Gln-Pro-. Incubation of the two-chain zymogen with lipopolysaccharide resulted in the cleavage of a Phe-Ile bond between residues 72 and 73 of the light chain. Concomitant with this cleavage, the A (72 amino acid residues) and B chains derived from the light chain were formed. The complete amino acid sequence of the A chain was determined by automated Edman degradation. The A chain contained a typical segment which is similar in sequence to a family of repeats in human beta 2-glycoprotein I, complement factors B, protein H, C4b-binding protein, and coagulation factor XIII b subunit. The NH2-terminal sequence of the B chain was Ile-Trp-Asn-Gly-. This chain contained the serine-active site sequence-Asp-Ala-Cys-Ser-Gly-Asp-Ser-Gly-Gly-Pro-. These results indicate that horseshoe crab factor C exists in the hemocytes in a single-chain zymogen form and is converted to an active serine protease by hydrolysis of a specific Phe-Ile peptide bond.

Amino Acid Sequence↗

Bovine high molecular weight kininogen. The amino acid sequence, positions of carbohydrate chains and disulfide bridges in the heavy chain portion.

The existence of two types of circulating bovine plasma high molecular weight kininogen (HMWK) was predicted from analyses of complementary DNAs coding for this protein (Kitamura, N., Takagaki, Y., Furuto, S., Tanaka, T., Nawa, H., and Nakanishi, S. (1983) Nature 305, 545-549). The present protein-based study provided evidence in support of the proposed amino acid sequence derived from analysis of the cDNA clone, and the results confirm the existence of two types of circulating HMWK. Type I HMWK contains a heavy chain composed of 361 residues, while the heavy chain of type II HMWK contains 359 residues. The amino acid sequences of type I and type II HMWK determined in this study were identical to that inferred from the cDNA sequence with the exception of microheterogeneity observed in the cDNA at position 87 (Glu/Gln) and 168 (Lys/Arg). The heavy chain of type I HMWK contains 4 asparagine-linked carbohydrate chains at Asn-69, -150 (or -151), -179, and -186, while the heavy chain of type II HMWK contains these and an additional carbohydrate chain at Asn-264. In addition, a carbohydrate chain was found to be O-glycosidically linked to Thr-118 in both chains. Among nine disulfide linkages found in HMWK, eight intrachain disulfide pairs were established in the heavy chain. One interchain disulfide bridge occurs between the heavy chain and the light chain. This disulfide pairing, as well as repeating amino acid sequences observed in the heavy chain, provides strong evidence for the existence of three homologous domains in the heavy chain of bovine HMWK.

Amino Acid Sequence↗

Prothrombin Tokushima, a replacement of arginine-418 by tryptophan that impairs the fibrinogen clotting activity of derived thrombin Tokushima.

Structural studies on a hereditarily abnormal prothrombin, prothrombin Tokushima, have been performed to identify the difference responsible for its reduced fibrinogen clotting activity upon conversion to thrombin. The prothrombin sample used was from a heterozygote but contained exclusively a defective prothrombin molecule, since the patient was heterozygous for both dysprothrombinemia and hypoprothrombinemia. Amino acid sequence analysis of a peptide isolated from a lysyl endopeptidase digest of the abnormal thrombin indicated that Arg-418 (equivalent to Asn-101 in the chymotrypsin numbering system) had been replaced by Trp. This amino acid substitution can result from a single nucleotide change in the codon for Arg-418 (CGG----TGG). The Arg----Trp replacement found in the thrombin portion of prothrombin Tokushima appears to reduce its interaction with various substrates including fibrinogen and platelet receptors and accounts for the recurrent bleeding episode observed in the propositus.

Amino Acid Sequence↗

Differing expression patterns and evolution of the rat kininogen gene family.

The present investigation using molecular cloning and sequence analysis concerns the examination of the molecular basis for different expression patterns of two types of the rat kininogen genes. We show that the low molecular weight and high molecular weight forms of K kininogens are produced from a single gene through alternative usage of two 3'-coding regions, whereas only the low molecular weight forms of T kininogens are generated as a result of several mutational changes in the high molecular weight-specifying regions of both T-I and T-II kininogen genes. The mutational changes include a nucleotide substitution at the polyadenylation/processing signal site, nucleotide deletions resulting in the frame-shift mutation, and an insertion of the type 2 Alu-equivalent sequence. Because kininogens represent a multifunctional protein comprising the proteinase-inhibitory activity, the kinin moiety, and the clotting activity, these results present evidence indicating the molecular basis for the disappearance of a part of the gene functions. We also show that the K and T kininogen genes as well as the two T kininogen genes are extremely homologous, excluding and including the above mutational changes, respectively. These structural relationships allow us to envisage evolutionary processes for the generation of the rat kininogen gene family, particularly for the disappearance of a part of the gene functions.

Animals↗

Structural analysis and specific expression of microsomal cytochrome P-450(M-1) mRNA in male rat livers.

cDNA clones for the P-450(M-1) mRNA, which exhibits a male-specific expression in rat livers, were isolated by using synthetic oligonucleotides as the probes. Sequence analysis of the cDNAs showed that P-450(M-1) mRNA contains 1,853 nucleotides in addition to a poly(A) chain, and a single open reading frame of 1,500 nucleotides encodes a polypeptide of 500 amino acids with a Mr = 57,187. The predicted NH2-terminal sequence of 30 amino acids agrees well with that of the purified protein determined by Edman degradation, and the predicted primary structure included all the partial sequences of six internal peptides of P-450(M-1) obtained by the proteolytic digestion and a conserved amino acid sequence containing a putative heme-binding cysteine, proximate to the COOH terminus of the molecules. P-450(M-1) showed relatively high sequence similarity with P-450b (Fujii-Kuriyama, Y., Mizukami, Y., Kawajiri, K., Sogawa, K., and Muramatsu, M. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 2793-2797) (52% similarity), P-450-3b (Ozols, J., Heinemann, F. S., and Johnson, E. F. (1985) J. Biol. Chem. 260, 5427-5434) (64%), P-450-1 (Tukey, R. H., Okino, S., Barnes, H., Griffin, K. J., and Johnson, E. F. (1985) J. Biol. Chem. 260, 13347-13354) (74%), P-450PBc1 (Leighton, J. K., DeBrunner-Vossbrinck, B. A., and Kemper, B. (1984) Biochemistry 23, 4598-4603) (71%), while its sequence similarity with 3-methylcholanthrene-inducible P-450c and P-450d is rather low. Consequently, P-450(M-1) could be structurally classified into the phenobarbital-inducible type of P-450 gene family. RNA blot analysis using a synthetic oligonucleotide specific for P-450(M-1) revealed that P-450(M-1) mRNA was expressed exclusively in the livers of mature male rats in a sex-specific manner, but not in other tissues so far examined.

Amino Acid Sequence↗

Identification and quantification of 5-hydroxypipecolic acid and hydroxyproline in mammalian brain and blood by selected ion monitoring.

A method for the analysis of 5-hydroxypipecolic acid and 4-hydroxyproline in mammalian brain and blood is reported. The identification and quantification of the two hydroxyimino acids were accomplished with gas chromatography/mass spectrometry including a selected ion-monitoring technique following HPLC prepurification. The lower limit of detection for the method is 2 to 10 pmol. The amounts of 5-hydroxypipecolic acid and 4-hydroxyproline in blood were 20 to 30 pmol/ml and 3 to 6 nmol/ml, respectively. Their concentrations in the rabbit whole brain were determined to be 5 and 120 pmol/g, respectively.

Adult↗

Piperidine: a microelectrophoretic study in the mammalian brain.

Using unit recording and electrophoretic techniques, the action of piperidine on unit activity of the brain of the rat was studied. Piperidine excited 31%, and inhibited 4% of cortical cells tested. In the hippocampus and caudate nucleus, piperidine excited larger proportions of the cells tested. The actions of piperidine were blocked by tetraethylammonium but not by scopolamine.

Acetylcholine↗

Nucleotide sequences of immunoglobulin epsilon genes of chimpanzee and orangutan: DNA molecular clock and hominoid evolution.

To determine the phylogenetic relationships among hominoids and the dates of their divergence, the complete nucleotide sequences of the constant region of the immunoglobulin epsilon-chain (C epsilon 1) genes from chimpanzee and orangutan have been determined. These sequences were compared with the human epsilon-chain constant-region sequence. A molecular clock (silent molecular clock), measured by the degree of sequence divergence at the synonymous (silent) positions of protein-encoding regions, was introduced for the present study. From the comparison of nucleotide sequences of alpha1-antitrypsin and beta- and delta-globin genes between humans and Old World monkeys, the silent molecular clock was calibrated: the mean evolutionary rate of silent substitution was determined to be 1.56 X 10(-9) substitutions per site per year. Using the silent molecular clock, the mean divergence dates of chimpanzee and orangutan from the human lineage were estimated as 6.4 +/- 2.6 million years and 17.3 +/- 4.5 million years, respectively. It was also shown that the evolutionary rate of primate genes is considerably slower than those of other mammalian genes.

Animals↗

Complete amino acid sequence of cytochrome c551 from Erythrobacter species strain OCh 114.

The complete amino acid sequence of cytochrome c551 isolated from an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114, was determined. The cytochrome molecule was composed of a total of 119 amino acid residues and its molecular weight including heme was calculated to be 13,235. The sequence was (Sequence: see text). Its molecular weight indicates that this cytochrome is of the L-type. Sequence alignment with other bacterial cytochromes c shows that this cytochrome is similar to cytochromes c of Rhodobacter capsulatus, Rhodobacter sphaeroides, and Paracoccus denitrificans, which were grouped into the alpha-3 subcluster from the 16S rRNA sequence analysis.

Amino Acid Sequence↗

Structural comparison of bovine erythrocyte, brain, and liver NADH-cytochrome b5 reductase by HPLC mapping.

NADH-cytochrome b5 reductases purified from bovine erythrocytes and from bovine brain and liver microsomes solubilized with lysosomal protease were subjected to structural analysis by using HPLC mapping, amino acid analysis of the resulting peptides, and NH2-terminal sequence analysis of apoproteins. HPLC maps of the tryptic peptides derived from these enzymes were very similar to each other, and amino acid analysis of the HPLC-separated peptides indicated that the structures of these enzymes are identical except for the NH2-terminal region. The NH2-terminal sequence of the brain enzyme determined by automated Edman degradation was as follows: NH2-Phe-Gln-Arg-Ser-Thr-Pro-Ala-Ile-Thr-Leu-Glu-Asn-Pro-Asp- Ile-Lys-Tyr-Pro-Leu-Arg-Leu-Ile-Asp-Lys-Glu-Val-Ile- This sequence is identical to that of liver enzyme except that the liver enzyme started at the 3rd Arg or 4th Ser. The NH2-terminal amino acid residue of the soluble erythrocyte enzyme was not detected by automated Edman degradation. The sequence analysis of a tryptic peptide from the erythrocyte enzyme indicated that Leu is present before the NH2-terminal Phe of the brain enzyme. The recently reported sequence of the apparently identical protein (Ozols et al. (1985) J. Biol. Chem. 260, 11953-11961) differs in two amino acid assignments from our sequence.

Amino Acid Sequence↗