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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 721 records · Page 40Linked to original sources
PubMed1986

[Analysis of pregnancy outcome after chemotherapy of trophoblastic disease].

The pregnancy outcome of 57 women who had been treated for trophoblastic disease, between 1975 and 1982, was studied. All patients had regular menstrual cycle within six months after the last chemotherapy. Frequency of secondary infertility is 5% (3/60). No correlation between the amount of chemotherapy and secondary infertility was apparent. Of eighty-three pregnancies in 57 women, 55 pregnancies or 66.3% terminated in full term deliveries, 4 or 4.8% terminated in premature deliveries. Eleven of the 83 or 11.3% ended in spontaneous abortions and 2 or 2.4% in recurrent hydatiditorm mole. Only one infant (1.7%) had congenital malformation. There was no increase in fetal wastage or congenital anomaly when compared with pregnancies prior to chemotherapy or after untreated molar patients. Among the 59 live born infants, 4 or 6.8% infants belong to light for date, 49 or 83.1% to appropriate for date and 6 or 10.2% to heavy for date. Chemotherapic agents, mainly MTX and Act-D, appeared to have no effect on fetal growth. The incidence of choriocarcinoma subsequent to pregnancy in treated patients was 1.8% (1/57) and was 0.6% (2/365) in untreated molar patients (n.s.).

Abortion, Spontaneous↗
PubMed1986

Identification of calmodulin-binding proteins in pure mitochondria by photoaffinity labeling.

Calmodulin-binding proteins (CaM-BPs) were identified in the submitochondrial fractions obtained from highly purified rat liver mitochondria. The matrix fraction contained five CaM-BPs with apparent molecular weights (MW) of 27K, 38K, 47K, 76K, and 84K Da in a Ca solution. Electron transfer particles also contained five CaM-BPs, but their MWs were 31K, 35K, 53K, 66K, and 73K in a Ca solution. Nonspecific calcium-independent CaM-BPs were also identified in matrix fractions, having MWs of 10K, 25K, and 49K Da.

Animals↗
PubMed1985

A direct evidence of the localization of mitochondrial calmodulin.

The presence and localization of mitochondrial calmodulin was directly proved immuno-electron microscopically by the protein A-gold technique. In the ultra-pure mitochondria the complexes of anti-calmodulin antibody and protein A-gold clearly showed the localization of mitochondrial calmodulin on the inner membrane and in the matrix space.

Animals↗
PubMed1985

Survey of calcineurin activity towards nonprotein compounds and identification of phosphoenol pyruvate as a substrate.

Calcineurin, originally identified as a calmodulin-dependent phosphoprotein phosphatase (Stewart, A.A. et al. (1982) FEBS Lett. 137, 80-84) also uses p-nitrophenyl phosphate and phosphotyrosine as substrates (Pallen, C.J. and Wang, J.H. (1983) J. Biol. Chem. 258, 8550-8553). We have surveyed a wide range of nonprotein phosphocompounds and found that several synthetic aryl phosphocompounds serve as calcineurin substrates. Among more than 20 naturally occurring phosphocompounds tested, only phosphoenol pyruvate possesses significant calcineurin substrate activity. The phosphoenol pyruvate phosphatase activity is dependent on Ni2+ and Mn2+, is stimulated by calmodulin, and is inhibited by a monoclonal antibody to calcineurin, thus indicating that it is an intrinsic property of calcineurin. The results suggest that functional roles of calcineurin may include actions of the enzyme toward nonprotein phosphocompounds.

Amino Acids↗
PubMed1985

Effects of androgen and polyamines on the phosphorylation of nucleolar proteins from rat ventral prostates with particular reference to 110-kDa phosphoprotein.

The effects of testosterone (in vivo) and polyamines (in vitro) on the phosphorylation of nucleolar proteins of rat ventral prostates were studied. Phosphorylation of nucleolar proteins was accomplished by incubation of isolated nucleoli with [gamma-32P]ATP at 37 degrees C for 10 min followed by electrophoretic separation and autoradiographic demonstration of phosphorylated proteins. Of several nucleolar phosphoproteins observed in ventral prostates of castrated rats, the incorporation of 32P into 110-kDa protein was remarkably augmented by the testosterone treatment. The stimulation became evident as early as 4 h after the injection of the hormones, reaching 3-4-fold of the control level and was efficiently prevented by cycloheximide injection 3 h before killing. 5 alpha-Dihydrotestosterone gave similar results to testosterone, but estradiol-17 beta failed to stimulate the phosphorylation of 110-kDa protein. Polyamines and cyclic nucleotides did not affect the phosphorylation, but, when phenylmethanesulfonyl fluoride was omitted from the standard medium, spermine and spermidine showed a distinct effect: 110-kDa phosphoprotein was completely abolished with a concomitant increase of 59-kDa phosphoprotein in both cases of castrated and testosterone-primed rats. The effect of polyamines seems to be due to the stimulation of degradation of the protein which is presumably catalyzed by a serine protease.

Animals↗
PubMed1985

Demonstration of different metal ion-induced calcineurin conformations using a monoclonal antibody.

It has been suggested that calcineurin, a calmodulin-stimulated phosphatase, may exist in different metal ion-dependent conformational states (Pallen, C.J., and Wang, J. H. (1984) J. Biol. Chem. 259, 6134-6141). Evidence in favor of this hypothesis comes from studies involving a monoclonal antibody, VA1, which is specific for the small (beta) subunit of calcineurin. This antibody inhibits Ni2+-stimulated but not Mn2+-stimulated phosphatase activity against p-nitrophenyl phosphate and phosphorylase kinase. Inhibition is not due to competition of the antibody with substrate or to interference with metal ion binding to the enzyme. Complex formation between the antibody and calcineurin can be demonstrated either in the presence of Mn2+ or Ni2+ or in the absence of metal ion activators. These results indicate that the active conformational states of calcineurin are metal ion dependent, that the monoclonal antibody VA1 affects the Ni2+-induced conformational change of the enzyme, and that the beta subunit of calcineurin plays a critical role in the expression of Ni2+-stimulated phosphatase activity.

Animals↗
PubMed1985

Endoscopic bipolar electrocoagulation in massive upper gastrointestinal bleeding.

We have reviewed 50 cases of upper gastrointestinal bleeding treated by endoscopic bipolar electrocoagulation (BPEC) and assessed its value in the management of massive bleeding. Initial hemostasis was achieved in 94% of cases with an overall rebleeding rate of 19.1%. The rebleeding rate was high among patients requiring blood transfusions more than 2,000 ml (47.3%) and those with acute gastric mucosal lesion (AGML) (35.3%). In AGML one or two primary sites of bleeding can be effectively controlled initially, but rebleeding tends to occur from other sites. Mortality from the direct effects of bleeding was also high in massive bleeders (33.3%) and those with AGML (22.2%); the overall mortality, including deaths from ongoing underlying diseases, was 38%. Although BPEC failed to alter the fatal outcome of patients with massive acute mucosal bleeding, permanent or temporary hemostasis contributed to reducing the amount of blood transfusions, avoiding emergency operation, preventing rapid deterioration and prolonging the survival time. Endoscopic BPEC has proven to be an effective emergency hemostatic method in massive bleeding of the upper gastrointestinal tract as an alternative to surgical intervention.

Adolescent↗
PubMed1985

Solubilization and characterization of rat brain alpha 2-adrenergic receptor.

alpha 2-Adrenergic receptors labelled by [3H]-clonidine (alpha 2-agonist) can be solubilized from the rat brain in a form sensitive to guanine nucleotides with a zwitterionic detergent, 3-[3-(cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS). About 40% of the original [3H]CLO binding sites in the membranes were solubilized with 6 mM CHAPS. Separation of the soluble [3H]CLO-bound complex was performed by the vacuum filtration method using polyethylenimine-treated GF/B filters. Solubilized [3H]CLO binding sites retained the same pharmacological characteristics of membrane-bound alpha 2-adrenergic receptors. Scatchard plots of [3H]CLO binding to solubilized alpha 2-receptors were curvilinear, indicating the existence of the two distinct binding components. Solubilized receptors were eluted as a single peak from Bio-Gel A-1.5 m column with a Stokes radius of 6.6 nm. The isoelectric point was 5.6-5.8. Regulations of the receptor binding by guanine nucleotides, monovalent cations, and sulfhydryl-reactive agents were maintained intact in the soluble state, whereas those by divalent cations were lost. The apparent retention of receptors and guanine nucleotide binding regulatory component(s) in the soluble state may allow a investigation of the regulation mechanisms of the brain alpha 2-adrenergic receptor system at the molecular level.

Animals↗
PubMed1985

A uniform focal spot X-ray tube with improved MTF and kW rating.

Focal spots of conventional x-ray tubes have a "twin-peaked" intensity distribution perpendicular to the axis of the tube. This results in a poorer modulation transfer function (MTF) than would be obtained with a uniform intensity distribution having the same input power rating (kW). It is demonstrated that such an intensity distribution can be obtained by employing a ribbon-shaped filament. Experimental results are presented for both the ribbon filament and a conventional helical coil using a stationary anode. For a 0.3-mm focal spot spatial frequency of 2.0 c/mm, a uniform intensity distribution gave an MTF of about 50%, compared to 20% for a conventional tube at the same kW rating.

Radiography↗
PubMed1984

Initial detection of [3H]clonidine binding to solubilized rat brain alpha 2-adrenergic receptors: regulation by guanine nucleotides.

Alpha 2-adrenergic receptors labeled by [3H]clonidine (alpha 2-agonist) can be solubilized from the rat brain with a zwitterionic detergent, 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane sulfonate (CHAPS). CHAPS-solubilized receptors have the same characteristics of membrane-bound alpha 2-receptors in the brain, and the regulation of receptor binding by guanine nucleotides is retained in the soluble state.

Adenosine Triphosphate↗
PubMed1984

Quantitative analysis of rat brain alpha 2-receptors discriminated by [3H]clonidine and [3H]rauwolscine.

Quantitative analysis of direct ligand binding of both [3H]clonidine and [3H]rauwolscine to the rat cerebral cortex alpha 2-receptors indicates the existence of two affinity states of the same receptor populations. In the presence of Mn2+, the high affinity state of [3H]clonidine binding was increased, whereas the high affinity state of [3H]rauwolscine binding was reduced. By contrast, GTP in micromolar ranges caused a decrease of the agonist high affinity state and an increase of the antagonist high affinity state. The total receptor sites and the respective separate affinities for both radioligands were approximately equal to their control values under all conditions, indicating that Mn2+ and GTP modulate the proportion of the two affinity states of the receptor. These results can be incorporated into a two-step, ternary complex model involving a guanine nucleotide binding protein (N protein) for the agonist and antagonist interaction with the alpha 2-receptor. Furthermore, the effects of GTP on the interaction of both ligands with the two affinity states can be mimicked by EDTA. It is suggested that divalent cations induce the formation of the receptor-N protein binary complex showing high affinity for agonists and low affinity for antagonists.

Animals↗
PubMed1984

Species difference in sensitivity to the diabetogenic action of triphenyltin hydroxide.

The sensitivity to the diabetogenic action of triphenyltin hydroxide (TPTOH) was investigated in 5 species of experimental animals. A single oral administration of TPTOH produced marked hyperglycemia and triglyceridemia in rabbits and hamsters, but no evidence of diabetes was found in mice, rats and guinea-pigs. No morphological abnormality was observed in islet tissue from TPTOH-treated hamsters.

Animals↗
PubMed1984

The possible involvement of adenylate cyclase inhibition in the field potential suppression through alpha-2 adrenergic receptors in the bed nucleus of the stria terminalis.

Catecholamines, such as norepinephrine (NE), cause a field potential suppression through alpha-2 adrenergic receptors in thin sections of the bed nucleus of the stria terminalis. Phosphodiesterase inhibitors or cyclic AMP (cAMP) analogues attenuate the NE-induced suppression. These results suggest that the NE-induced suppression is mediated by adenylate cyclase inhibition and a resultant decrease of intracellular cAMP content.

1-Methyl-3-isobutylxanthine↗
PubMed1984

Interleukin 2 (IL2) is assigned to human chromosome 4.

The human gene for interleukin 2 (IL2) was assigned to chromosome 4 using human-mouse somatic cell hybrids and Southern filter hybridization of cell hybrid DNA. To identify IL2, a recombinant DNA probe ( pIL2 - 50A ) was used which contained a human interleukin 2 cDNA insert which hybridized to a 3.5-kb fragment in human DNA when cleaved with the restriction enzyme EcoRI.

Animals↗
PubMed1984

A sensitive fluorometric assay for dopamine-beta-hydroxylase activity by high-performance liquid chromatography.

A sensitive and specific fluorometric assay for dopamine-beta-hydroxylase (DBH) activity is described. The main natural substrate, dopamine (DA), was used and incubated under optimal conditions. Norepinephrine (NE) formed enzymatically from DA was isolated by an aluminum oxide column and was analyzed by high-performance liquid chromatography (HPLC) with trihydroxyindole fluorescence. Epinephrine (EN) was added to the incubation mixture as an internal standard after incubation, and this assay was therefore highly reproducible. HPLC conditions were settled to elute the product, NE, prior to the substrate, DA, and the internal standard, EN, between NE and DA. Only catecholamines produced significant peaks, and therefore, this assay is highly specific. We applied this method to measure the DBH activity in human serum and cerebrospinal fluid.

Chromatography, High Pressure Liquid↗