PubMed Health⌕ Search

Biomedical subjects

T Miyata

Publications and source records attributed to T Miyata.

At least 703 records · Page 39Linked to original sources
PubMed1984

[Studies on tissue concentrations of cefoperazone and piperacillin classified by the site of the wall of gallbladder and concentration of piperacillin in the bile after operation].

In selection of drugs to be used in the treatment of biliary tract infections, sensitivity of causative organisms to drugs and tissue concentrations of the drugs constitute important factors. In the present study we treated patients with cholelithiasis with cefoperazone (CPZ) and piperacillin (PIPC), both of which have been reported to show high concentrations in the bile, and concentrations of the drugs in serum, cholecystic bile and various sites of the wall of gallbladder were determined. In addition the drug concentrations in the serum and bile at the 1st and 7th postoperative days were also determined. The following results were obtained. Comparison of concentrations of CPZ and PIPC at various sites of the wall of gallbladder revealed that both drugs showed high levels in the bottom, body and neck areas of the gallbladder with no difference by sites. The concentration ratios against serum for these drugs were 71.8 and 83.6%, showing good transference into tissue. The mean concentrations of CPZ and PIPC in the cholecystic bile were as high as 448.8 and 381.6 micrograms/ml, the ratio against serum being about 4:1. The serum concentrations of PIPC at the 1st and 7th postoperative days were 116 and 137 micrograms/ml at 60 minutes after starting drip infusion, with no difference between these 2 days. In the bile concentrations of PIPC on both postoperative days showed the peak levels of 2,587 and 1,157 micrograms/ml at 120 minutes after starting drip infusion. The concentrations at the 1st postoperative day were higher. The recovery rate of PIPC from the bile was also higher at the 1st postoperative day. From the results that both drugs showed high levels in the wall of gallbladder and also showed high levels in the bile immediately after the operation, PIPC and CPZ are considered to be effective drugs for biliary tract infections.

Bile↗
PubMed1984

[Renovascular hypertension with a solitary kidney associated with retrocaval ureter: a case report].

A case of renovascular hypertension in a patient with a congenitally solitary kidney associated with retrocaval ureter is reported. Aortorenal bypass with autogenous saphenous vein graft and concomitant mobilization of the ureter by division and reanastomosis of the inferior vena cava were performed. Pathogenesis of the stenotic lesion of the renal artery was fibromuscular dysplasia. Postoperative improvement of hypertension was not so good as expected. Soon after administration of nifedipine (20mg/day) was started, blood pressure decreased down to 130/80mmHg and had been well controlled. Problems regarding renovascular hypertension with a solitary kidney and surgical treatment of retrocaval ureter are discussed.

Adult↗
PubMed1984

[Pharmacological effects of brovanexine hydrochloride (BR-222) on the respiratory tract system, particularly on the respiratory tract fluid, mucociliary transport and cough].

Pharmacological effects of brovanexine hydrochloride (BR-222), a new expectorant, on the respiratory tract system was studied in comparison with that of bromhexine hydrochloride. 1. When doses ranging from 5 to 40 mg/kg of BR-222 were given orally (p.o.) or intraduodenally (i.d.) to rats, rabbits and dogs, it caused a significant increase in the output volume of respiratory tract fluid (RTF). It was almost as potent as bromhexine, but its pattern of increasing RTF was different from that of bromhexine. The increase in the serous ingredient of RTF after BR-222 administration seemed to be more remarkable than that after bromhexine treatment, though both drugs had no influences on the component ratio of glucose or protein in the RTF of dogs. 2. BR-222 at 10 and 20 mg/kg (i.d.) showed a tendency to reduce the viscosity of RTF in anesthetized dogs and so did bromhexine. A dose of 10 mg/kg (i.d.) of BR-222 also showed a tendency to reduce the viscosity of sputum obtained from the SO2-exposed rabbits. 3. A dose of 6 mg/kg (i.m.) of BR-222 caused a significant increase in the mucociliary transport rate in unanesthetized pigeons; in contrast with this, bromhexine caused a slight decrease. 4. Both drugs given orally showed no antitussive effects when examined by the "coughing dog" method.

Animals↗
PubMed1983

Complete nucleotide sequence of the human corticotropin-beta-lipotropin precursor gene.

The nucleotide sequence of an 8658-base-pair human genomic DNA segment containing the entire corticotropin-beta-lipotropin precursor gene has been determined, and some sequence features of the gene and its flanking regions have been analysed. The gene is composed of 7665 base pairs including two introns of 3708 and 2886 base pairs. Comparison of the 5'-flanking sequences of the human, bovine and mouse corticotropin-beta-lipotropin precursor genes reveals the presence of a highly conserved region, which contains sequences of 14-15 base pairs homologous with sequences located upstream of the mRNA start site of other glucocorticoid-regulated genes.

Adrenocorticotropic Hormone↗
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

Primary structures of beta- and delta-subunit precursors of Torpedo californica acetylcholine receptor deduced from cDNA sequences.

The nicotinic acetylcholine receptor (AChR) from fish electric organ and mammalian skeletal muscle is the best characterized neurotransmitter receptor (reviewed in refs 1-3). The AChR from the electroplax of the ray Torpedo californica consists of five subunits present in a molar stoichiometry of alpha 2 beta gamma delta (refs 4-6); the apparent molecular weights of the alpha-, beta-, gamma- and delta-subunits are 40,000 (40K), 50K, 60K and 65K, respectively. Knowledge of the primary structures of these constituent polypeptides would facilitate the understanding of the molecular mechanism underlying the function of the neurotransmitter receptor. Recently, we have cloned cDNA for the alpha-subunit precursor of the T. californica AChR and have deduced the primary structure of this polypeptide from the nucleotide sequence of the cloned cDNA. Here we report the cloning and nucleotide analysis of cDNAs for the AChR beta- and delta-subunit precursors. The primary structures of the two polypeptides deduced from the cDNA sequences reveal conspicuous amino acid sequence homology among these and the alpha-subunits. The three subunits contain several highly conserved regions which may be essential for the receptor function or inter-subunit interaction.

Amino Acid Sequence↗
PubMed1983

Experimental studies on an artificial esophagus using a collagen-silicone copolymer.

An artificial esophagus consisting of a collagen-silicone copolymer prepared by special chemical and physical procedures proved to be advantageous by both physical and histological examination. The adherence to the host tissue was satisfactory when collagen was used. The esophageal prosthesis was anastomosed to the jejunum in 5 dogs and no leakage occurred during 10-30 days. In subsequent experiments, use of the artificial prosthesis in the thoracic esophagus was followed by leakage in 5 of 14 cases (35 per cent). Five of these dogs survived for over 30 days, and the longest survival was 212 days. The incidence of leakage was acceptable but stricture was a common long-term complication. Further studies are underway to refine the prosthesis, the method of anastomosis, and post-operative management.

Animals↗
PubMed1983

Unusual evolutionary conservation and frequent DNA segment exchange in class I genes of the major histocompatibility complex.

From comparisons of homologous DNA sequences for many different genes, it was shown that the silent positions of protein-encoding regions and introns evolve at high and remarkably similar rates for different genes. In addition, both silent positions and introns behave like clocks; they accumulated base substitutions at approximately constant rates with respect to geological time. The rates of evolution were estimated to be 5.5 X 10(-9), 3.7 X 10(-9), and 5.3 X 10(-9) per site per year for silent positions, short introns (less than approximately equal to 300 base pairs), and long introns (more than approximately equal to 500 base pairs), respectively. Contrary to expectation from the evolutionary clocks, DNA sequence comparison between pHLA 12.4 (a cloned HLA sequence) of man and Ld together with other H-2 genes of mouse, the class I genes of the major histocompatibility complex, revealed a surprisingly small amount of base substitution for both the introns and the silent positions; the degree of divergence is only about 60% of that of standard genes in the same species comparison. Furthermore, several segmental homologies have been observed between the class I genes of mouse, suggesting the frequent occurrence of gene conversion or double unequal crossing-over in evolution. Interrelations between the extreme polymorphism of the class I genes, the low evolutionary drift of the introns and the silent positions, and the frequent gene conversion or unequal crossing-over within the mouse genes are discussed.

Animals↗
PubMed1983

The complete nucleotide sequence of the influenza virus neuraminidase gene of A/NJ/8/76 strain and its evolution by segmental duplication and deletion.

The neuraminidase (NA) gene from A/New Jersey (NJ)/8/76 (H1N1, formerly Hsw1 N1) strain isolated in 1976 was cloned into pBR322 and its complete nucleotide sequence was determined. The NJ8 NA gene is 1458 nucleotides long and the sequence predicted the primary structure of the NA molecule comprising of 469 amino acids with a molecular weight of 51,628. Comparison with other NA sequences of the N1 subtype strains which were isolated in 1933-1934 identified the highly variable regions at the amino-terminal stalk region and the carboxy-terminal regions. Potential glycosylation sites encoded by a 15 base-pair unit sequence are arrayed tandemly at the stalk regions. The lengths of stalk regions are highly variable because of segmental deletions in old NA genes. Possible mechanisms for such deletions are discussed.

Animals↗
PubMed1983

Pharmacological studies on dl-glaucine phosphate as an antitussive.

Antitussive effect, toxicity and other related pharmacological properties of dl-1,2,9,10-tetramethoxy-6a,alpha-aporphine phosphate (dl-glaucine phosphate, DL-832) were studied in comparison with those of codeine. Acute toxicity of DL-832 in mice was 2/5 to 7/10 of that of codeine for any routes of i.v., i.p., s.c. and p.o. The antitussive effect as tested by "coughing dog and cat" methods and Domenjoz's method in cats was 1/5 to 4/5 that of codeine, according to the routes administered. Safety margin in antitussive effect was similar to or less than that of codeine. Differing from codeine, levallorphan exerted no influence on the antitussive effect of DL-832. In vitro, DL-832 exerted moderate relaxant actions on normal tone and on contractions induced by histamine and acetylcholine of tracheal muscle. In vivo, it showed a moderate relaxant effect on histamine-induced bronchial constriction. The decrease in the volume of respiratory tract fluid caused by DL-832 was smaller than that by codeine. DL-832 slightly reduced the transportation rate of intratracheal foreign body, although to much lesser extent as compared to codeine. On respiration, blood pressure and heart rate, DL-832 showed depressant effects and moreover it caused changes in ECG. However, all of these effects were similar to and a little weaker than those observed with codeine. DL-832 prolonged hexobarbital sleeping time significantly. Neither analgesic nor anticonvulsant effect was observed. When given in larger doses, DL-832 inhibited intestinal transportation in vivo, although this effect was much weaker than that of codeine. DL-832 showed slight local anesthetic effect.

Anesthetics, Local↗