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Biomedical subjects

T Miyake

Publications and source records attributed to T Miyake.

At least 37 records · Page 2Linked to original sources

Electromagnetic moments of the beta-emitting nucleus 16N.

The nuclear magnetic dipole moment mu and electric quadrupole moment Q of the beta-emitting 16N(Ipi = 2(-), T(1/2) = 7.13 s) nucleus have been determined for the first time by detecting its beta-NMR in a MgO crystal and beta-NQR (nuclear quadrupole resonance) in a TiO (2) crystal to be /mu/ = (1.9859+/-0.0011) mu(N) and /Q/ = (17.9+/-1.7) mb, respectively. Although the prediction of mu given by the Hartree-Fock calculation agrees well with the experiment, an abnormally small effective charge for neutrons is required to account for the experimental Q.

Journal Article↗

Eicosapentaenoic acid (EPA) induces Ca(2+)-independent activation and translocation of endothelial nitric oxide synthase and endothelium-dependent vasorelaxation.

Eicosapentaenoic acid (EPA), but not its metabolites (docosapentaenoic acid and docosahexaenoic acid), stimulated nitric oxide (NO) production in endothelial cells in situ and induced endothelium-dependent relaxation of bovine coronary arteries precontracted with U46619. EPA induced a greater production of NO, but a much smaller and more transient elevation of intracellular Ca(2+) concentration ([Ca(2+)]i), than did a Ca(2+) ionophore (ionomycin). EPA stimulated NO production even in endothelial cells in situ loaded with a cytosolic Ca(2+) chelator 1,2-bis-o-aminophenoxythamine-N',N',N'-tetraacetic acid, which abolished the [Ca(2+)]i elevations induced by ATP and EPA. The EPA-induced vasorelaxation was inhibited by N(omega)-nitro-L-arginine methyl ester. Immunostaining analysis of endothelial NO synthase (eNOS) and caveolin-1 in cultured endothelial cells revealed eNOS to be colocalized with caveolin in the cell membrane at a resting state, while EPA stimulated the translocation of eNOS to the cytosol and its dissociation from caveolin, to an extent comparable to that of the eNOS translocation induced by a [Ca(2+)]i-elevating agonist (10 microM bradykinin). Thus, EPA induces Ca(2+)-independent activation and translocation of eNOS and endothelium-dependent vasorelaxation.

Animals↗

Mutations in the TATA-binding protein, affecting transcriptional activation, show synthetic lethality with the TAF145 gene lacking the TAF N-terminal domain in Saccharomyces cerevisiae.

The general transcription factor TFIID, which is composed of the TATA box-binding protein (TBP) and a set of TBP-associated factors (TAFs), is crucial for both basal and regulated transcription by RNA polymerase II. The N-terminal small segment of yeast TAF145 (yTAF145) binds to TBP and thereby inhibits TBP function. To understand the physiological role of this inhibitory domain, which is designated as TAND (TAF N-terminal domain), we screened mutations, synthetically lethal with the TAF145 gene lacking TAND (taf145 Delta TAND), in Saccharomyces cerevisiae by exploiting a red/white colony-sectoring assay. Our screen yielded several recessive nsl (Delta TAND synthetic lethal) mutations, two of which, nsl1-1 and nsl1-2, define the same complementation group. The NSL1 gene was found to be identical to the SPT15 gene encoding TBP. Interestingly, both temperature-sensitive nsl1/spt15 alleles, which harbor the single amino acid substitutions, S118L and P65S, respectively, were defective in transcriptional activation in vivo. Several other previously characterized activation-deficient spt15 alleles also displayed synthetic lethal interactions with taf145 Delta TAND, indicating that TAND and TBP carry an overlapping but as yet unidentified function that is specifically required for transcriptional regulation.

Amino Acid Substitution↗

Histological study of the development of the embryo and early larva of Oreochromis niloticus (Pisces: Cichlidae).

The developmental stages of Oreochromis niloticus are similar to those described in other mouth-breeding tilapias except that, as in zebrafish, no cavity was found in the blastula. Variation in the rate of development of the embryo and larva of O. niloticus was found within a clutch of eggs as well as between clutches. Hatching glands are described for the first time in tilapias. They are widely distributed within the ectoderm covering the head, body, tail, and surface of the yolk sac near its attachment to the embryo. Timing of larval development is similar to that in other mouthbrooding tilapias, but is slower than that found in substrate-spawning tilapias. A pneumatic duct connects the swimbladder to the digestive tract and swimbladder inflation and initiation of feeding occurs at about the same time. The digestive tract of the larva 8 and 9 days after fertilization is similar to that found in the adult, except that there are no digestive glands. An endocrine pancreatic islet was first seen 76 h after fertilization. A prominent thymus gland is present at 100 h. Hematopoietic tissue develops in the vicinity of the pronephros during early larval development. A spleen develops later, 7 days after fertilization.

Animals↗

Intralobar pulmonary sequestration supplied by multiple anomalous arteries: report of a case.

Pulmonary sequestration is abnormal pulmonary tissue that has separated from the normal pulmonary parenchyma, is not connected to the tracheobronchial tree, and is supplied by a systemic artery. We describe herein a case of intralobar pulmonary sequestration found in a 66-year-old man who was admitted to our hospital with hemoptysis, coughing, and fever. Angiography showed that the branches of the 11th left intercostal artery and a bronchial artery had formed a hypervascular area in the lower part of the left lung. Bronchial artery embolization and subsequent embolization of the left 11th intercostal artery were performed in an attempt to control the recurrent hemoptysis. These treatments were unsuccessful, and he was transferred to our department of surgery after coughing up about 400 ml of fresh blood. A left lower lobectomy was performed. The resected lung contained a large feeding artery, some acute and partly organizing inflammatory lesions within collapsed lung parenchyma, and massive intra-alveolar hemorrhage in the peripheral area. The patient had an uneventful recovery and was discharged 22 days after his operation.

Aged↗

Identification of epistatic interactions involved in non-insulin-dependent diabetes mellitus in the Otsuka Long-Evans Tokushima Fatty rat.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type non-insulin-dependent diabetes mellitus (NIDDM) in humans. Our present investigation was designed to identify epistatic interactions influencing NIDDM by performing least squares analysis of variance of all pairs of informative markers in 160 F2 progenies bred from an intercross of OLETF and Fischer-344 rats. We identified four interactions between Nidd15/of (chromosome 7) and Nidd16/of (chromosome 14), Nidd15/of and Nidd17/of (chromosome 15), Nidd16/of and Nidd18/of (chromosome 15), and Nidd16/of and Nidd19/of (chromosome 17), which account for a total of approximately 40% of the genetic variation of entire glucose levels after glucose challenge in the F2. The Nidd16/of locus, which is involved in three of four digenic interactions, and the Nidd19/of are likely to correspond to Nidd2/of and Nidd14/of, NIDDM loci previously identified in the F2 by single-QTL model and multiple-QTL model, respectively, while Nidd15/of, Nidd17/of and Nidd18/of loci reflect novel NIDDM loci. An aberrant increase of the entire glucose level due to synergism occurs in the double OLETF homozygote genotype of Nidd15/of and Nidd16/of, and of Nidd16/of and Nidd19/of, as well as in the OLETF homozygote genotypes of Nidd15/of and Nidd16/of, respectively, combined with the heterozygote genotypes of Nidd17/of and Nidd18/of. These findings demonstrate that inter-allelic interactions are likely to be an important component of NIDDM susceptibility.

Animals↗

Intercellular adhesion molecule-1 in patients with idiopathic interstitial pneumonia.

This study focuses on a possible role of intercellular adhesion molecule-1 (ICAM-1) in interstitial pulmonary diseases. We determined a soluble form of ICAM-1 in serum and bronchoalveolar lavage fluid (BALF) using ELISA in patients with usual interstitial pneumonia (UIP), bronchiolitis obliterance organizing pneumonia (BOOP), or nonspecific interstitial pneumonia (NSIP). In addition, we investigated the expression of ICAM-1 in the lung tissues of these patients by means of immunohistochemical staining. Serum levels of soluble ICAM-1 were significantly higher in patients with UIP or NSIP than in healthy subjects, and were also high in patients with BOOP. The soluble ICAM-1 in BALF tended to be higher in patients with UIP, BOOP, or NSIP than in normal subjects. A significant correlation was seen between soluble levels of ICAM-1 in serum and BALF. In the immunostaining of ICAM-1 of the lung tissues, ICAM-1 expression was more pronounced in patients with UIP than in those with BOOP or NSIP. The increased expression of ICAM-1 was seen in type II alveolar epithelium and vascular endothelium in patients with interstitial pneumonia. A positive correlation was observed between the degree of ICAM-1 expression in the lung tissues and the BALF levels of soluble ICAM-1. The expression of ICAM-1 in type II alveolar epithelium suggests that ICAM-1 plays a specific role in the fibrotic process of the lung, and that the measurement of soluble ICAM-1 in sera and BALF could be a useful marker for evaluating the progression of fibrosis.

Adult↗

Doppler echocardiographic studies of diastolic cardiac function in the human fetal heart.

Fetal echocardiography has been used for the noninvasive evaluation of human fetal cardiac anatomy, function, and hemodynamics. The purpose of the present study was to use Doppler echocardiographic methods to measure diastolic flow velocity patterns across the tricuspid and mitral valves in human fetuses during gestation. Fifty normal fetuses, 35 fetuses with intrauterine growth retardation (IUGR), and 30 fetuses of diabetic mothers (DM) were studied. Peak flow velocities during early diastole (peak E wave) and peak flow velocities during atrial contraction (peak A wave) were measured, and the peak E/A ratio was calculated. The peak E/A ratio of the left ventricle in fetuses increased gradually with increasing gestational age (r = 0.57, p < 0.05), and the peak E/A ratio of the right ventricle in fetuses increased linearly with increasing gestational age (r = 0.48, p < 0.05). In early gestational age, the peak E/A ratios of both the left and right ventricle in fetuses with IUGR and of DM were not significantly different from those in the controls. However, in late gestational age, the peak E/A ratios of both the left and right ventricle in fetuses with IUGR and of DM were significantly smaller than those in the controls. This gradual decrease in the peak E/A ratio during gestation may represent the maturational or developmental alteration of diastolic cardiac properties in utero. Fetuses with IUGR and of DM may have abnormal diastolic cardiac function in later gestation.

Diastole↗

[Malignant lymphoma of the prostate: a case report].

A case of a primary malignant lymphoma of the prostate is presented. An 82-year-old man visited our hospital complaining of anal pain. Digital rectal examination revealed an enlarged prostate gland, which caused a rectal stricture. A computed tomographic scan and magnetic resonance imaging (MRI) showed a large mass arising from the prostate and protruding to the rectum. According to the Working Formulation, he was diagnosed with non-Hodgkin's lymphoma of B-cell origin, diffuse, mixed, small and large cell. The results of bone marrow puncture and imaging studies led to the diagnosis of primary malignant lymphoma of the prostate. Because of poor performance status deriving from severe anal pain, radiation therapy was performed to control the pain. After improvement of his performance status, he received combination chemotherapy consisting of cyclophosphamide, adriamycin, vincristine and predonisone (CHOP regimen). His prostate markedly diminished in size, but pneumonia developed. His respiratory condition rapidly deteriorated, and he died of respiratory failure about two and a half months after the onset of his illness. Malignant lymphoma involving the prostate, whether primary or secondary, is very rare. In our understanding, this case is thought to be the 28th clinical case of a malignant lymphoma of the prostate in Japan.

Aged↗

Sumio Umezawa.

Explore the source record for details and available documents.

Aminoglycosides↗

Characterization of a novel trans-activation domain of BRCA1 that functions in concert with the BRCA1 C-terminal (BRCT) domain.

Mutations in the breast cancer susceptibility gene, BRCA1, account for a significant proportion of hereditary breast and ovarian cancers. The BRCA1 C-terminal (BRCT) domain, which can activate transcription when fused to a heterologous DNA binding domain, is required for BRCA1 function in suppression of tumorigenesis. Here, we provide evidence for a new activation domain in BRCA1 that lies adjacent to the BRCT domain. We name the two domains AD1 and AD2, respectively. Like AD2, the newly discovered AD1 can act independently as an activation domain in both yeast and human cells. However, unlike AD2, AD1 activity in mammalian cells is cell type context-dependent. Furthermore, combination of these two domains in mammalian cells can result in a robust synergy in transcriptional activation. A highly conserved coiled-coil motif in AD1 is required for the cooperative transcription activation. Interestingly, the functional cooperativity between AD1 and AD2 is absent in certain breast and ovarian cancer cell lines, although each domain can still activate transcription. Therefore, the differential and cooperative actions of the two activation modules may contribute to the heterogeneous risk of BRCA1 mutations in different tissues.

Amino Acid Sequence↗

A functional comparison of BRCA1 C-terminal domains in transcription activation and chromatin remodeling.

The BRCA1 C-terminal (BRCT) domain is present in a number of proteins that are involved in various aspects of chromosomal events. The BRCT domain of BRCA1 is important for its function in DNA repair and transcriptional activation. When tethered to chromosomal DNA, this region of BRCA1 is capable of inducing changes in chromatin structure. Despite the sequence homology and functional proximity shared by the BRCT-containing proteins, it is not clear whether different BRCT domains confer a common biochemical activity. Much less is known about the functional significance of the characteristic amino acid residues in the BRCT motif. Here, we show that chromatin remodeling and transcription activation is not a common feature of BRCT domains. However, the BRCT domain of the multi-functional repressor-activator protein 1 (RAP1) can activate transcription and remodel chromatin in a manner similar to that shown for the BRCA1 BRCT domain. Most of the conserved amino acid residues in the second BRCA1 BRCT domain are essential for its function in transcriptional activation. In contrast, mutations of many analogous amino acid residues in the RAP1 BRCT domain greatly elevate the transcriptional activity. These data indicate that the conserved residues in these two BRCT domains may play different roles in transcriptional activation.

Amino Acid Sequence↗

Sphingosylphosphorylcholine induces Ca(2+)-sensitization of vascular smooth muscle contraction: possible involvement of rho-kinase.

Sphingosylphosphorylcholine (SPC), a sphingolipid, concentration-dependently (1-50 microM) induced contraction and slight elevation of the cytosolic Ca(2+) concentration ([Ca(2+)](i)) in smooth muscle of the pig coronary artery, the result being a marked increase in the force/[Ca(2+)](i) ratio. In alpha-toxin- or beta-escin-permeabilized, but not Triton X-100-permeabilized, vascular strips, SPC induced contraction at constant [Ca(2+)](i) (pCa 6.3) in the absence of GTP, whereas a G-protein-coupled receptor agonist, histamine, required the presence of GTP to induce the contraction. The Rho-kinase blocker, Y-27632 (10 microM) abolished the SPC-induced Ca(2+)-sensitization, without affecting the Ca(2+)-induced contraction. These results suggest that SPC induces Ca(2+)-sensitization of force in vascular smooth muscle, presumably through the activation of Rho-kinase (or a related kinase).

Amides↗

Quantum distribution of protons in solid molecular hydrogen at megabar pressures

Solid hydrogen, a simple system consisting only of protons and electrons, exhibits a variety of structural phase transitions at high pressures. Experimental studies based on static compression up to about 230 GPa revealed three relevant phases of solid molecular hydrogen: phase I (high-temperature, low-pressure phase), phase II (low-temperature phase) and phase III (high-pressure phase). Spectroscopic data suggest that symmetry breaking, possibly related to orientational ordering, accompanies the transition into phases II and III. The boundaries dividing the three phases exhibit a strong isotope effect, indicating that the quantum-mechanical properties of hydrogen nuclei are important. Here we report the quantum distributions of protons in the three phases of solid hydrogen, obtained by a first-principles path-integral molecular dynamics method. We show that quantum fluctuations of protons effectively hinder molecular rotation--that is, a quantum localization occurs. The obtained crystal structures have entirely different symmetries from those predicted by the conventional simulations which treat protons classically.

Journal Article↗