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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 415 records · Page 23Linked to original sources
PubMed1990

[Thromboxane A2 could be involved in bronchial hyperresponsiveness to methacholine in asthmatic subjects but not in bronchitic subjects].

To determine whether the involvement of thromboxane A2 in bronchial hyperresponsiveness is specific to asthma, we examined the effects of a selective thromboxane synthetase inhibitor (OKY-046) and a cyclooxygenase inhibitor (indomethacin) on bronchial responsiveness to methacholine in patients with bronchial asthma and chronic bronchitis. The provocative concentration of methacholine producing a 20% fall in forced expiratory volume in one second (PC20-FEV1) was measured before and after oral administration of OKY-046 and indomethacin in eight asthmatic and 10 bronchitic subjects. Baseline FEV1 value was not altered by OKY-046 or indomethacin. The geometric mean value of PC20-FEV1 increased significantly (p less than 0.005) from 1.78 to 4.27 mg/ml after OKY-046 in asthmatic subjects, but not in bronchitic subjects. On the other hand, PC20-FEV1 was not altered by indomethacin in all subjects. It was concluded that the involvement of thromboxane A2 in bronchial hyperresponsiveness may be specific to asthma.

Asthma↗
PubMed1990

Layer-by-layer analysis of macular diseases with objectively measured visual functions.

New methods were developed to measure layer-by-layer visual function in macular diseases objectively and quantitatively. A prototype apparatus for foveal cone densitometry that combines a modified fundus camera, independent optic pathways and a personal computer was assembled. Using a two-way density technique, the density and regeneration time of the foveal cone pigment can be measured objectively. Data on layer-by-layer visual function can be obtained when a-wave, b-wave and oscillatory potentials are recorded by focal macular electroretinography (FMERG). Since the retinal origin of each component is different, the comparative measurement of these components indicates which layer of the macula is disturbed. The simultaneous recording of FMERG and visual evoked response (VER) might be useful in determining which part of the visual pathway is impaired. These methods of measurement were reviewed and some examples of layer-by-layer analysis were shown.

Adult↗
PubMed1990

[Relationship between cough threshold to inhaled tartaric acid and sex, smoking and atopy in humans].

It has been reported that angiotensin converting enzyme inhibitor (ACE-I) elicits dry cough more frequently in women than in men. This study was designed to evaluate whether airway cough receptors are more sensitive in women than in men. Cough threshold to inhaled tartaric acid was measured in 33 men and 29 women. In non-atopic and non-smoking subjects, geometric mean value of cough threshold in women was 10.0 (GSEM, 1.29) %, which was significantly (p less than 0.02) lower than that in men, 22.5 (GSEM, 1.30) %. In non-atopic men, the cough threshold was significantly (p less than 0.05) lower in smokers (9.3 (GSEM, 1.57) %) than in non-smokers. In non-smoking women, the cough threshold was significantly (p less than 0.02) lower in atopic subjects (4.2 (GSEM, 1.33) %) than in non-atopic subjects. These results demonstrated that airway cough receptors may be more sensitive in women, smoking men and atopic women.

Administration, Inhalation↗
PubMed1989

Expression of normal and abnormal porcine kidney D-amino acid oxidase in Escherichia coli: purification and characterization of the enzymes.

Expression plasmids for normal and abnormal porcine D-amino acid oxidases (E.C. 1.4.3.3, DAO) have been constructed from cloned cDNA that encodes the entire protein sequence of DAO, and the enzymes were expressed in Escherichia coli cells on a large scale. The expressed enzymes were purified to apparent homogeneity. The molecular weight of the normal DAO (38 kD) was identical with that of DAO purified from porcine kidney, whereas that of the abnormal DAO was 39 kD, which comprised the normal DAO with an additional decapeptide at its amino terminus. However, the specific activities of the two enzymes were comparable with that of natural DAO. The results indicate that the bulky decapeptide does not affect the structure necessary for the catalytic function of DAO in the amino-terminal region. The use of a GTG triplet in the 5'-untranslated region of DAO cDNA as the initiation codon for the synthesis of the abnormal DAO is suggested.

Amino Acid Sequence↗
PubMed1989

Calcium-induced shape change of calmodulin with mastoparan studied by solution X-ray scattering.

Solution x-ray scattering using synchrotron radiation as an x-ray source was used to analyze the Ca2+-dependent shape change of pig brain calmodulin in detail. The radius of gyration of calmodulin at 10 mg/ml was increased by 0.9 A. The increase was nearly completed when 2.5 mol of Ca2+/mol of calmodulin was added, whereas the radius of gyration of calmodulin with mastoparan decreased by about 3 A with an increasing Ca2+ concentration up to 4 mol of Ca2+/mol of calmodulin. At a moderate angle of region, both scattering profiles from calmodulin with or without Ca2+ displayed clear humps at s = 0.03 A-1 which are characteristic of a dumbbell structure. However, in the presence of mastoparan, the hump in the scattering profile became obscure and later disappeared with the third and fourth Ca2+ binding to calmodulin. These findings are attributable to the Ca2+-induced shape change of calmodulin with mastoparan from a dumbbell structure to a non-dumbbell structure in which the distance between the two lobes of calmodulin become closer by a bend in the central helix.

Animals↗
PubMed1989

Biosynthesis of a renin binding protein.

The biosynthesis of a porcine renin binding protein (RnBP), which specifically binds to renin and forms an inactive high molecular weight renin, was investigated. mRNAs from various porcine tissues were used to investigate in vitro protein synthesis. The kidney mRNA directed the synthesis of a high level of RnBP, whereas the liver, adrenal and pituitary gland mRNAs gave as low but significant level of it. The in vitro synthesized RnBP as well as the immunologically detected RnBP synthesized in vivo had the same molecular weight, 42,000, as that of the purified protein. Moreover, both the human and rat kidney mRNAs directed the synthesis of this protein identified with an anti-porcine RnBP antibody. These results strongly indicate that RnBP, present in various mammalian species, is synthesized in renin-producing tissues as the mature size and undergoes binding with renin without proteolytic processing.

Adrenal Glands↗
PubMed1989

Purification of a 51 kDa endo-beta-N-acetylglucosaminidase from Staphylococcus aureus.

A bacteriolytic enzyme obtained from the culture fluid of Staphylococcus aureus FDA 209P was purified to homogeneity utilizing dye-ligand affinity column chromatography, hydrophobic interaction high pressure liquid chromatography (HPLC) and hydroxyapatite HPLC. Subsequent characterizations indicated that the purified enzyme acted as endo-beta-N-acetylglucosaminidase. The molecular weight determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was 51,000 and the isoelectric point was higher than 10. The optimum pH for the enzyme activity on whole cells of Micrococcus luteus as a substrate was 8.0. Some heavy metal cations (Cu2+ and Zn2+) inhibited the enzyme activity at a concentration of 0.1 mM and others (Ba2+, Mg2+ and Co2+) showed a stimulating effect at a concentration of 1 mM.

Acetylglucosaminidase↗
PubMed1989

Analysis of a recycling-impaired mutant of low density lipoprotein receptor in familial hypercholesterolemia.

A mutant low density lipoprotein (LDL) receptor with abnormal ligand binding and recycling abilities was found in a patient with familial hypercholesterolemia. The molecular weights of the precursor and the mature form of the receptor were 72,000 and 115,000, respectively, which were about 45,000 smaller than those of the normal receptor. The mutant receptor was concluded to be present on the cell surface because the mature form was susceptible to Pronase digestion, and specific monoclonal antibody against the LDL receptor (IgG-C7) could bind to the cell surface. This mutant receptor could not bind LDL, but could bind other ligands for the LDL receptor, beta-migrating very low density lipoprotein, and the apolipoprotein E-lipid complex. After the receptor bound to the ligand, it disappeared from the cell surface of the mutant cells faster than that of normal cells, showing that, in the mutant cells, the receptor was not efficiently recycled back to the cell surface. Southern blotting of the genomic DNA from the patient showed a large deletion of about 12 kilobases around the epidermal growth factor precursor homology domain. For further characterization of the mutant, we cloned a 9.4-kilobase EcoRI/XbaI fragment, which was expected to contain the deletion joint. Mapping and sequencing analyses of the receptor gene showed that exons 7-14 were deleted. The nucleotide sequence suggested that this mutation may have occurred by recombination between repetitive Alu sequences in introns 6 and 14 of the receptor gene. The recombination brought about a complete deletion of the gene coding the epidermal growth factor precursor homology domain. The characteristics of the receptor protein produced by this mutation were similar to those of an artificial mutation constructed by Davis et al. (Davis, C. G., Goldstein, J. L., Südhof, T. C., Anderson, R. G. W., Russell, D. W., and Brown, M. S. (1987) Nature 326, 760-765) in which the whole gene coding this domain was deleted. The clinical phenotype of the patient having this mutation was similar to that of so-called "receptor-defective" type familial hypercholesterolemia, in which cells show detectable, but markedly reduced activity of the LDL receptor.

Base Sequence↗
PubMed1989

Hereditary macular dystrophy without visible fundus abnormality.

We found an unusual form of macular dystrophy in three patients from two generations of the same family. The fundi of these patients appeared normal by ophthalmoscopy and fluorescein angiography, even in an older patient and in patients with poor visual acuity. Results of full-field electroretinograms were also normal in both cone and rod components. Focal macular electroretinograms were severely affected, however, indicating retinal impairment in the macular region. Results of Tübingen perimetry were consistent with electroretinographic findings. Since the condition was progressive, this disease is thought to be a hereditary macular dystrophy without visible fundus abnormality.

Adult↗
PubMed1989

Decrease in the fluidity of brush-border membrane vesicles induced by gentamicin. A spin-labeling study.

In our previous paper (Horio et al., Biochim Biophys Acta 858: 153-160, 1986), we reported that the addition of gentamicin in vitro to rabbit renal brush-border membrane vesicles decreases the apparent Vmax of Na+-dependent D-glucose transport without affecting the apparent Km. In the present study, we investigated the effects of gentamicin on the physical state of spin-labeled rabbit renal brush-border membranes, using electron spin resonance spectrometry. Brush-border membrane vesicles were prepared from outer cortex (mainly contains early proximal tubule) and outer medulla (containing primarily late proximal tubule), and the gentamicin toxicities in both preparations were compared. Significant decreases were observed in the membrane fluidity of 5 mM gentamicin-treated brush-border membranes. The fluidity of outer cortical brush-border membranes was affected at both 25 degrees and 35 degrees, whereas that of outer medullary membranes was affected only at 35 degrees. Two different stearic acid spin labels revealed that gentamicin affected the fluidity only in the superficial region of the membranes. We also demonstrated that the gentamicin-induced decreases in Na+-dependent D-glucose transport and in the membrane fluidity were recovered by washing gentamicin-treated brush-border membranes. We suggest that gentamicin binds to the superficial region of brush-border membranes and inhibits Na+-dependent D-glucose transport across brush-border membranes through the decrease in the membrane fluidity.

Animals↗
PubMed1989

In vitro and in vivo antagonists against parathyroid hormone-related protein.

Four analogues of parathyroid hormone-related protein (PTHrP), PTHrP(7-34)NH2, (10-34)NH2, (15-34)NH2 and (20-34)NH2, were synthesized and their antagonistic activity against PTHrP(1-34) was examined in vitro and in vivo. In vitro studies revealed that all four analogues antagonized PTHrP-stimulated cyclic AMP production in rat osteosarcoma cells (ROS 17/2.8), and that PTHrP(7-34)NH2 and PTHrP(10-34)NH2 had potent antagonistic activity. In vivo experiments in nude mice also revealed that PTHrP(7-34)NH2 completely inhibited hypercalcemia induced by PTHrP(1-34), indicating that these analogues antagonize the effects of PTHrP(1-34) in vitro and in vivo.

Adenylyl Cyclases↗
PubMed1989

Identification of secretin diastereoisomers produced during synthesis.

The byproducts P-1 and P-2, which were produced during the synthesis of porcine secretin, were isolated in pure form from the crude secretin by HPLC. These were identified by a combination of amino acid analysis, enzymatic digestion, and isocratic or linear gradient reversed-phase (RP)-HPLC. The amino acid compositions of P1 and P2, determined by amino acid analysis after acid hydrolysis, were found to be the same as those of porcine secretin without distinction between L-and D-amino acids. But, HPLC of their digestive fragments with trypsin and alpha-chymotrypsin differed from that of secretin. The fragments, S7-12 of P-1 and S13-21 of P-2 were determined to be different from the corresponding fragments obtained from secretin by HPLC analysis of their digestive fragments. The amino acid composition of each acid hydrolysate, following digestion with D-amino acid oxidase, was found to have less leucine or alanine content than secretin. The HPLC analysis of the fragments from P-1 and P-2 by tryptic and alpha-chymotryptic digestion showed that they are the same as those from synthetic D-Leu10 secretin or D-Ala17 secretin, respectively. Consequently, P-1 and P-2 are concluded to be the secretin diastereoisomers, D-Leu10 and D-Ala17 secretin, respectively.

Amino Acids↗
PubMed1989

Pseudopolymorphism and phase stability in four solid forms of (6R,7R)-7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-(Z)-2-methoxy- iminoacetamid]-3- [(4-carbamoyl-1-quinuclidinio)methyl]-8-oxo-5-thia-1-azabicyclo - [4,2,0]oct-2-ene-2-carboxylate (E1040).

(6R,7R)-7-[2-(5-Amino-1,2,4-thiadiazol-3-yl)-(Z)-2-methoxy- iminoacetamid]-3- [(4-carbamoyl-1-quinuclidinio)methyl]-8-oxo-5-thia-1-azabicyclo [4,2,0]oct-2-ene-2-carboxylate (1; E1040) was isolated as alpha-(decahydrate), beta-(pentahydrate), and gamma-form (anhydrate) crystals and the X-ray amorphous form. The relationship between the pseudopolymorphic crystal forms of this compound and water content was studied by X-ray diffractometry, coulometric moisture analysis, thermal analysis, and hygroscopic and vacuum-freeze-drying experiments. The phase transition of crystalline 1 clearly indicated the effect of water content on dehydration. During dehydration, hydrated alpha-form (decahydrate) crystals and beta-form (pentahydrate) crystals became anhydrate gamma-form crystals, with the diffraction angle shifting toward shorter spacing accompanied by line broadening. These results indicate conversion of hydrate 1 crystals to the anhydrous form and contraction of the crystal lattice. It was estimated that the decahydrate (alpha-form) crystals contain 8 mol/mol crystal water and 2 mol/mol adhesion water, and that the pentahydrate (beta-form) crystals contain 4 mol/mol crystal water and 1 mol/mol adhesion water. These estimates were made by comparing the data from equilibrium hydration experiments and vacuum-freeze-drying experiments. It thus follows that gamma-form crystals are anhydrate and the X-ray amorphous form exists in either the hydrous or anhydrous form.

Adhesiveness↗
PubMed1989

Human urinary prokallikrein--structural analysis on activation mechanism.

The complete amino acid sequence of human urinary kallikrein has been determined. The enzyme was a single polypeptide which comprised 238 amino acid residues. In the case of prokallikrein, a propeptide which was consisted of seven amino acid residues was attached to N-terminal isoleucine of kallikrein. The sequence of Asn-X-Thr(Ser), common to glycosylation site, was identified at positions 78-80, 84-86 and 141-143. It has been shown from the sequence of kallikrein that Arg(-1)-Ile(1) and Arg(87)-Gln(88) bonds are hydrolyzed with trypsin on rapid activation of prokallikrein and the formation of disulfide-linked two chain kallikrein.

Amino Acid Sequence↗
PubMed1989

Purification and immunological properties of human urinary kallikrein and prokallikrein.

Human urinary prokallikrein and kallikrein have been purified from the same source of urine simultaneously. The anti-kallikrein and anti-prokallikrein antibodies were raised in rabbits using the purified preparations. With respect to solid phase enzyme immunoassay (EIA), immunoaffinity column chromatography, and single radial immunodiffusion, reactivity of each antibody with kallikrein was distinctly different from that with prokallikrein. Kallikrein could be determined by anti-kallikrein antibody-immobilized EIA below 20 ng per ml, whereas prokallikrein was undetectable. Prokallikrein became detectable at higher concentrations, although it was less reactive than kallikrein. The anti-prokallikrein antibody-immobilized EIA detected both kallikrein and prokallikrein with the same sensitivity. However, the binding capacity for kallikrein was about one-third less than that for prokallikrein. The results show that kallikrein in human urine may be determined directly and selectively. Similar difference in reactivity was observed with immunoaffinity column chromatography and single radial immunodiffusion. The presence of 3-4 antigenic sites per molecule was indicated by quantitative precipitin reaction, and it is suggested from analysis of amino acid sequence of kallikrein by the method of Hopp and Woods that four hydrophilic regions exist in kallikrein molecule.

Chromatography, Affinity↗
PubMed1989

Evaluation of the significance of "redistribution" in I-123 IMP SPECT in cerebrovascular disorders--a comparative study with PET.

We evaluated the significance of redistribution in 123I-IMP SPECT study using PET. Twelve lesions in ten patients were selected. These lesions were classified into the following three groups; ischemia, infarction of subacute phase and infarction of chronic phase. All lesions with ischemia or subacute infarction showed good or moderate redistribution. Three of four lesions with chronic infarction showed no redistribution. The mean values of rCBF and rCMRO2 were highest in the lesions with good redistribution, but there was no differences in rOEF with the degree of redistribution. In conclusion, the tissue with good redistribution is not always viable and it was impossible to predict a region with increased rOEF by redistribution alone.

Adult↗
PubMed1989

Reliability and validity of the Childhood Autism Rating Scale--Tokyo version (CARS-TV).

A Japanese translation of the Childhood Autism Rating Scale (CARS) (the Tokyo version of the CARS, CARS-TV) was used with 167 developmentally disabled children under age 16. Cronbach's coefficient alpha was .87. The interrater reliability (r) for each of the 15 scales based on 128 children ranged from .43 to .77 with an average of .62. Based on the 167 children, the total CARS-TV score demonstrated a satisfactory level of taxonomic validity (Thorndike, 1982) on DSM-III diagnostic groups. The total score discriminated infantile autism and other pervasive developmental disorders more efficiently from mental retardation without an additional diagnosis of pervasive developmental disorder than an IQ. The total score also showed a satisfactory concurrent validity on the overall rating of autism.

Adolescent↗