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A Murayama

Publications and source records attributed to A Murayama.

72 records · Page 4Linked to original sources
PubMed1981

[Two-dimensional echocardiographic approach to the localization of myocardial infarction: echocardiographic, electrocardiographic, and coronary arteriographic correlations (author's transl)].

Location of infarct lesions (IL) demonstrated by two-dimensional echocardiography (2DE) was correlated with electrocardiographic patterns of myocardial infarction and with the sites of obstructive lesions in the individual coronary arteries. The left ventricular wall was displayed by phased-array 2DE in 47 patients with healed myocardial infarction, 29 of whom underwent coronary arteriography. Segmental analysis of IL was performed on 14 segments, 10 of which were obtained by the parasternal short-axis recordings at the mitral (basal) and papillary muscle (mid) levels (each level containing the anterior septum, anterior wall, lateral wall, posterior wall, and posterior septum). The remaining 4 segments (septum, anterior wall, lateral wall, posterior wall) were obtained by the apical 2-chamber and 4-chamber recordings. IL were defined as akinesis, thinning, increased echo density, or absent systolic thickening of the left ventricular wall. All 22 patients with anterior infarction (Q in V1-V4) had IL in the mid anterior septum which was specific for the lesion of the left anterior descending artery (LAD). The presence or absence of the r wave in V1 could not predict the involvement of this segment. IL in the apical anterior wall and septum were observed in 21 of 22 patients. The presence of Q waves in V5, V6 suggested the additional involvement of the apical posterior wall. Additional Q waves in I, aVL indicated the extension of IL from the mild anterior septum to the basal anterior septum, anterior wall, and mid anterior wall. The basal and mid lateral walls appeared normal in most patients. This pattern of IL distribution was observed in 5 of 6 patients with a stenosis on the proximal LAD. All 14 patients with inferior infarction (Q in II, III, aVF) had IL in the mid posterior wall and posterior septum. In contrast, 5 patients with infero-posterior infarction (Q in II, III, aVF + R in V1) and 6 patients with posterior infarction (R in V1) had IL in the mid lateral as well as the mid posterior wall without an involvement of the posterior septum. Coronary arteriography revealed that all of the 10 patients with inferior infarction had a stenosis in the right coronary artery, whereas 6 patients with infero-posterior or posterior infarction invariably had a stenosis in the left circumflex coronary artery. It was concluded that 2DE provides a reliable method for detecting IL and anatomic location of myocardial infarction reflecting a specific coronary artery disease.

Adult↗
PubMed1980

Estrogen receptor of cow uterus. I. Characterization of native and proteolyzed "4S" estrogen receptors.

The estrogen receptor (ER) was separated from the cytoplasmic components of the cow uterus through successive gel filtrations of the cytosol in the presence of antipain, a protease inhibitor. The partially purified ER (designated as native "4S" ER) sedimented at 4.5S under both hypotonic (low salt) and hypertonic (0.4 M KCl) conditions. The molecular weight of native "4S" ER was estimated to be approximately 82,000 with a Stokes radius of 44 A. If purification was performed in the absence of antipain, native "4S" ER was very labile to a protease present in the cytoplasm. The modified ER (designated as modified "4S" ER) sedimented at 4.5S like native "4S" ER, but had a smaller stokes radius (35 A) and a smaller molecular weight (65,000). In the presence of 0.4 M NaSCN, native "4S" ER remained intact, but modified "4S" ER dissociated and gave a fragment which retained the estradiol binding site. This fragment sedimented at 2.9S and had a Stokes radius of approximately 24 A (molecular weight, approximately 29,000). In the presence of 0.4 M NaSCN, native "4S" ER remained intact, but modified "4S" ER dissociated and gave a fragment which retained the estradiol binding site. This fragment sedimented at 2.9S and had a Stokes radius of approximately 24 A (molecular weight, approximately 29,000). In the presence of Ca2+ ions and in the absence of antipain, the native ER was modified by the cytoplasmic protease to give ERs sedimenting at 3.8-4.5S. The presence of a cytoplasmic component which specifically binds with native "4S" ER to give "8S" ER under hypotonic conditions was indicated. Modified "4S" ER was unable to bind with this component.

Animals↗
PubMed1980

Estrogen receptor of cow uterus. II. Characterization of a cytoplasmic factor which binds with native "4S" estrogen receptor to give "8S" estrogen receptor.

Partial purification and characterization of a cytoplasmic component of cow uterus, which specifically binds with native "4S" estrogen receptor (ER) to give "8S" ER was carried out. The component was designated as "8S" ER-forming factor [("8S"ER)-FF]. ("8S"ER)-FF did not bind estradiol by itself. The Stokes radius of ("8S"ER)-FF was estimated to be approximately 51 A. ("8S"ER)-FF sedimented at around 6.9S in sucrose gradient centrifugation under hypotonic conditions. The molecular weight and frictional ratio of ("8S"ER)-FF were calculated to be 145,000 and 1.47, respectively. ("8S"ER)-FF was degraded by trypsin treatment, but was not affected by DNase or RNase. The Stokes radius of "8S" ER was estimated to be approximately 68 A. The molecular weight and frictional ratio of "8S" ER were calculated to be 225,000 and 1.69, respectively. "8S" ER was estimated to be a 1 : 1 complex between native "4S" ER and ("8S"ER)-FF. It was estimated that in the cow uterine cytosol, there was at least a 3-fold molar excess of ("8S"ER)-FF over the amount of "4S" ER. ("8S" ER)-FF inhibited both the Ca2+-dependent and -independent modifications of native "4S" ER by the cytoplasmic protease.

Animals↗
PubMed1980

Estrogen receptor of cow uterus. III. Molecular constitution of estrogen receptor-binding factors.

"8S" estrogen receptor-forming factor [("8S"ER)-FF], a cytoplasmic factor of cow uterus, which binds specifically with native "4S" estrogen receptor (ER) to give "8S" ER under hypotonic (low salt) conditions was dissociated in the presence of 0.4 M NaSCN into two kinds of subunits designated as component A and component B. Characterization of components A and B was performed. The Stokes radius and molecular weight of component A were estimated to be around 37 A and 58,000, respectively. Those of component B were estimated to be around 18.5 A and 13,700, respectively. These components did not bind with estradiol, and underwent molecular assembly depending on the salt concentration of the medium to give complexes, which, in turn, bound with native "4S" ER to give ERs with higher sedimentation coefficients. Component A [designated as "5S" ER-forming factor, ("5S"ER)-FF] bound with native "4S" ER to give "5S" ER, which was stable under hypertonic (0.4 M KCl) conditions. Under hypotonic conditions, component B formed a hexamer [designated as "6S" ER-forming factor ("6S"ER)-FF], which bound with native "4S" ER to give "6S" ER. "4S" ER was dissociated from "6S" ER under hypertonic conditions. ("8S"ER)-FF was shown to be a 1 : 1 complex of component A and the hexamer of component B. These factors [("5S"ER)-FF, ("6S"ER)-FF and ("8S"ER)-FF] which bind specifically with native "4S" ER to give ERs with higher sedimentation coefficients were designated as estrogen receptor-binding factors (ERBFs).

Animals↗
PubMed1980

Disorganization and in vitro assembly of the constituents of the cytoplasmic estrogen receptor system of cow uterus.

Analysis of estrogen receptor-binding factors (ERBFs) under isotonic (0.15 M KCl) conditions showed the presence of a factor designated as "7S" estrogen receptor-forming factor [("7S" ER)-FF], which binds with native "4S" estrogen receptor (ER) to form "7S" ER, besides the previously described component B and its hexamer ["6S" ER-forming factor, ("6S" ER)-FF]. Under hypertonic (0.4 M KCl) conditions at lower temperature (4 degrees C), ("7S" ER)-FF and the monomer of component B were present. Under hypertonic conditions at higher temperature (25 degrees C), ERBF existed as component A ["5S" ER-forming factor, ("5S" ER)-FF] and component B. ("7S" ER)-FF was estimated to be a 1 : 2 complex of component A and component B. Under isotonic conditions, approximately 30% of the cytoplasmic ER was "4S" form, and the rest was "6S" and "7S" forms. "5S" ER, "6S" ER, "7S" ER, and "8S" ER were reconstituted from partially purified native "4S" ER and the corresponding ERBFs. "5S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("5S" ER)-FF. "6S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("6S" ER)-FF. "7S" ER was estimated to be a 1 : 1 complex of native "4S" ER and ("7S" ER)-FF. "8S" ER was estimated to be a 1 : 1 complex of native "4S" ER and the "8S" ER-forming factor [("8S" ER)-FF] previously described, in which component A is bound to "4S" ER not directly, but via component B. A schematic molecular model of the in vitro dissociation and assembly of the constituents of the cytoplasmic ER system of cow uterus is presented.

Animals↗
PubMedDate not supplied

In vivo function of VDR in gene expression-VDR knock-out mice.

Vitamin D exerts many biological actions through nuclear vitamin D receptor (VDR)-mediated gene expression. The transactivation function of VDR is activated by binding 1alpha,25-dihydroxyvitamin D3[1alpha,25(OH)2D3], an active form of vitamin D. Conversion from 25(OH)D3 is finely regulated in kidney by 25(OH)D3 1alpha-hydroxylase[25(OH)D 1alpha-hydroxylase], keeping serum levels of 1alpha,25(OH)2D3 constant. Deficiency of vitamin D and mutations in the genes like VDR (type II genetic rickets) are known to cause rickets like lowered serum calcium, alopecia and impaired bone formation. However, the molecular basis of vitamin D VDR system in the vitamin D action in intact animals remained to be established. In addition, the 1alpha-hydroxylase gene from any species had not yet been cloned, irrespective of its biological significance and putative link to the type I genetic rickets. We generated VDR-deficient mice (VDR KO mice). VDR KO mice grew up normally until weaning, but after weaning they developed abnormality like the type II rickets patients. These results demonstrated indispensability of vitamin D-VDR system in mineral and bone metabolism only in post-weaning life. Using a newly developed cloning system, we cloned the cDNA encoding a novel P450 enzyme, mouse and human 1alpha-hydroxylase. The study in VDR KO mice demonstrated the function of liganded VDR in the negative feed-back regulation of 1alpha,25(OH)2D3 production. Finally, from the analysis of type I rickets patients, we found missense genetic mutations in 1alpha-hydroxylase, leading to the conclusion that this gene is responsible for the type I rickets.

Animals↗
PubMedDate not supplied

Multidisciplinary experience in the selection of patients for tubal sterilization.

Results of the use of a special protocol for evaluation of patients requiring tubal ligation is presented after applied by a multidisciplinary group. The authors conclude that the use of defined parameters of age, parity, marital union duration, number of children alive and the presence of maternal clinical pathology are useful to identify patients with smaller chances of regret after surgery.

Adolescent↗