Search PubMed⌕ Search

Biomedical subjects

M Yamaguchi

Publications and source records attributed to M Yamaguchi.

At least 1,009 records · Page 56Linked to original sources
PubMed1993

Expression of hepatic calcium-binding protein regucalcin mRNA is mediated through Ca2+/calmodulin in rat liver.

The effect of signal transduction-related factors was investigated to clarify the expression mechanism for mRNA of the hepatic Ca(2+)-binding protein regucalcin in the liver of rats. The change of regucalcin mRNA levels was analyzed by Northern blotting using liver regucalcin cDNA (0.6 kb). A single intraperitoneal administration of calcium chloride (15 mg Ca2+: 0.374 mmol/100 g body weight) to rats induced a remarkable increase of regucalcin mRNA in liver; the level was about 170% of controls at 30 min after administration. This increase was completely inhibited by simultaneous administration of trifluoperazine (5.0 mg/100 g), an antagonist of calmodulin. On the other hand, a single intraperitoneal administration of phorbol ester or dibutyryl cAMP (10-1,000 micrograms/100 g) did not cause a significant alteration of hepatic regucalcin mRNA levels. Also, administration of zinc, copper and cadmium (0.374 mmol of metal ion/100 g) did not have an appreciable effect on hepatic regucalcin mRNA levels. These findings demonstrate that the expression of hepatic regucalcin mRNA is mediated through Ca2+/calmodulin.

Animals↗
PubMed1993

Improved or fatal acute disseminated intravascular coagulation in systemic lupus erythematosus.

To analyze the outcome of systemic lupus erythematosus (SLE) associated with acute disseminated intravascular coagulation (DIC) and also to clarify the clinical factor(s) contributing to the outcome, we retrospectively investigated 120 SLE patients treated between 1981 and 1991. Eight of these patients (6.7%) developed acute DIC; four recovered and the other four died within 2 weeks of onset. Infection preceded acute DIC in all these patients. Acute DIC associated with atypical pneumonia was always fatal, while the patients with pharyngitis or urinary tract infection survived when they were treated adequately. Comparison of the dead and surviving groups revealed that the activity of SLE before the onset of DIC, the severity of DIC, and the treatment given for DIC and the coexistent infection were not significantly related to a fatal outcome. However, severe infection such as atypical pneumonia in patients with secondary immunodeficiency was likely to be fatal irrespective of the presence of DIC.

Acute Disease↗
PubMed1993

CD7, CD34-positive stem cell leukemia arising in agnogenic myeloid metaplasia.

Agnogenic myeloid metaplasia (AMM) is a chronic myeloproliferative disorder arising from a single hematopoietic cell. Approximately 5% of reported cases of AMM have terminated in leukemic crisis; however, the precise characteristics of the leukemic cells have rarely been reported. We report a case of AMM that occurred in a 42-year-old man and was complicated by leukemic transformation. The leukemic cells were morphologically lymphoblastoid cells with a negative reaction to peroxidase staining, and phenotypically characterized as CD7+, CD34+, HLA-DR+, CD4-, CD8-, CD10-, CD13-, and CD33-. Southern blot analysis revealed that T cell receptor-beta, gamma, and immunoglobulin heavy chain genes in leukemic cells were retained in germ-line configuration. These observations suggest that leukemic cells in our case involved early hematopoietic stem cells rather than those strictly committed to myeloid or lymphoid precursors. To our knowledge, this is the first report of stem cell leukemia arising in a patient with AMM.

Acute Disease↗
PubMed1993

Combined hereditary factor XI (plasma thromboplastin antecedent) deficiency, von Willebrand's disease, and xeroderma pigmentosum in a Japanese family.

We report a 28-year-old-Japanese male who had a skin tumor derived from variant type xeroderma pigmentosum (XP), combined with factor XI (FXI) deficiency and type IIB von Willebrand's disease (vWd). The patient had abnormal bleeding history on tooth extraction. FXI clotting activity (FXI:C) and antigen (FXI:Ag) were remarkably decreased (< 0.01 U/ml, < 0.02 U/ml, respectively). Factor VIII (FVIII) clotting activity, von Willebrand factor antigen (vWf:Ag), and ristocetin cofactor (RCoF) were 0.43 U/ml, 45%, and 57%, respectively. Ristocetin-induced platelet agglutination (RIPA) revealed hyper-aggregation compared with a normal control. Multimeric composition of vWf in plasma showed a reduction in high molecular weight forms. The family study revealed two other subjects with homozygous hereditary FXI deficiency and vWd, and five subjects with heterozygous FXI deficiency. The relationship between FXI deficiency and vWd is discussed and previously reported cases are reviewed.

Adult↗
PubMed1993

Effects of terguride, a partial D2 agonist, on MPTP-lesioned parkinsonian cynomolgus monkeys.

Behavioral effects of terguride, a partial dopamine D2 agonist, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned parkinsonian cynomolgus monkeys were compared with those of the dopamine agonist apomorphine and the dopamine antagonist haloperidol. Terguride alone ameliorated the parkinsonism without inducing any sign of excitability, irritability, or aggressiveness (hyperactivity). Apomorphine alone also ameliorated the parkinsonism but induced marked hyperactivity. Haloperidol alone caused worsening of the parkinsonism, inducing transient eyelid closure. In combination with apomorphine, terguride suppressed the hyperactivity induced by apomorphine without reducing its antiparkinsonian effects. Pretreatment with haloperidol suppressed both the antiparkinsonian effects and the hyperactivity induced by apomorphine. Terguride thus exhibits both antiparkinsonian and antihyperactivity effects in a monkey model of Parkinson's disease, suggesting that terguride might be beneficial for treating motor dysfunction and dopaminergic psychosis in advanced Parkinson's disease.

Aggression↗
PubMed1993

Intracellular multiplication of Legionella pneumophila in HL-60 cells differentiated by 1,25-dihydroxyvitamin D3 and the effect of interferon gamma.

We examined leukemic cells, HL-60, an acute promyelocytic leukemia cell line, after differentiation induced by 1,25-dihydroxyvitamin D3 (D3) and retinoic acid (A) for infection of Legionella pneumophila, the etiologic agent of Legionnaires' disease. We investigated the effect of interferon gamma (IFN-gamma) on the differentiated cells and on the intracellular growth of the bacteria. An examination of morphological and antigenic changes in the cells was also included in the study. After 4-day incubation with 10(-6)M D3 or A, the HL-60 cells differentiated into monocyte-like (D3-HL-60) or mature granulocyte-like (A-HL-60) cells, respectively. They were then infected with L. pneumophila. Intracellular multiplication of the bacteria was evident in D3-HL-60 cells but not in HL-60 or A-HL-60 cells. D3-HL-60 cells required a 24-h infection time for the intracellular growth of L. pneumophila. D3-HL-60 cells activated with human recombinant IFN-gamma for 1-24 h (gamma-IFN-D3-HL-60 cells) before infection markedly inhibited L. pneumophila multiplication, the effect of IFN-gamma being dose dependent. Surface marker analysis was carried out in HL-60, D3-HL-60, and gamma-IFN-D3-HL-60 cells. On D3-HL-60 cells, CD11b, CD11c, CD14, and CD35 antigen increased, whereas CD71 and HLA-DR antigen decreased. This finding suggested that HL-60 cells differentiated into monocyte-like cells; the acquisition of the complement receptors, CD11b(CR3) and CD35(CR1), seemed to be important for phagocytosis and for the subsequent intracellular multiplication of L. pneumophila. The gamma-IFN-D3-HL-60 cells showed an increase of CD16, CD36, CD71, and HLA-DR antigen, suggesting that they were in an activated state. Our study indicated, first, that D3 can induce human leukemic cells to differentiate into functional monocyte-macrophage-like cells that can support the intracellular multiplication of L. pneumophila and, second, that these differentiated leukemic cells can be activated by IFN-gamma to markedly inhibit bacterial growth.

Animals↗
PubMed1993

Characterization of plasma membrane H(+)-ATPase from salt-tolerant yeast Candida versatilis.

Plasma membrane was isolated from the salt-tolerant yeast Candida versatilis and the ATPase in plasma membrane was characterized. The ATPase was a typical H(+)-ATPase with similar properties to the Saccharomyces cerevisiae and Zygosaccharomyces rouxii enzymes. It was reacted with antibody (IgG) raised against S. cerevisiae plasma membrane H(+)-ATPase. The ATPase activity was not changed by adding NaCl and KCl to the assay solutions, but was increased by NH4+, especially by ammonium sulfate. In vivo stimulation of ATPase activity was observed by the addition of NaCl into the culture medium, as observed in Z. rouxii. No in vivo activation of H(+)-ATPase by glucose metabolism was observed in C. versatilis cells and the activity was independent of the growth phase, like Z. rouxii and unlike S. cerevisiae cells.

Azides↗
PubMed1993

Cytosolic protein phosphatase may turn off activated NADPH oxidase in guinea pig neutrophils.

Protein phosphatase inhibitors, okadaic acid and calyculin A, potentiated and elongated N-formyl-methionyl-leucyl-phenylalanine-induced superoxide anion (O2-) production in guinea pig neutrophils. The activity of NADPH oxidase in the membrane fraction prepared from phorbol 12-myristate 13-acetate-stimulated neutrophils was inactivated by the addition of the cytosol from resting neutrophils, such inactivation of NADPH oxidase was also suppressed by the protein phosphatase inhibitors. We previously reported that phosphorylation of the 46-kDa protein by protein kinase C is one of the activation mechanisms of NADPH oxidase-dependent superoxide anion production. In the cytosol fraction, we found protein phosphatase activity that catalyzed dephosphorylation of 32P-labeled phosphoproteins including the 46-kDa protein. Dephosphorylation of the 46-kDa protein was inhibited by the addition of okadaic acid and calyculin A. These results indicate that dephosphorylation of the 46-kDa protein by protein phosphatase is involved in the inactivation of NADPH oxidase. NADPH oxidase activity in guinea pig neutrophil may be regulated by the phosphorylation/dephosphorylation state of the 46-kDa protein by protein kinase C and protein phosphatase.

Animals↗
PubMed1993

Comparative metabolism and structure of BCKD-E2 in primary biliary cirrhosis.

The identification and cloning of the mitochondrial autoantigens in primary biliary cirrhosis (PBC) have provided new clues in disease pathogenesis. The two major autoantigens are the E2 subunits of pyruvate dehydrogenase and branched-chain ketoacid dehydrogenase (BCKD). Interestingly, one of these complexes, BCKD-E2, is already well known to clinical medicine based on its association with genetic mutations in maple syrup urine disease (MSUD). Patients with this disease have an inability to metabolize branched-chain amino acids. In the present study, we have taken advantage of the known sequence of BCKD-E2 from normal humans, and addressed the issue of whether there is an altered autoantigen sequence in hepatocytes of individuals with primary biliary cirrhosis. In particular, we examined both the leader sequence and the B-cell immunodominant epitope, the lipoic acid domain. In addition, because patients with PBC have autoantibodies to the BCKD-E2 complex, we have quantitated plasma levels of alpha-ketoacids potentially affected in maple syrup urine disease. These include pyruvic acid (PY), phenylpyruvic acid (PP), alpha-ketoisocaproic acid (KIC) alpha-ketoisovalerate (KIV) and alpha-keto-beta-methylvaleric acid (KMV). The levels of these alpha-ketoacids were compared in patients with primary sclerosing cholangitis and normal volunteers. The sequence of BCKD-E2 obtained from PBC hepatocytes showed homology with normal BCKD. Further studies of autoantigen structure and sequence are clearly indicated, including those involved in mitochondrial transport and localization. Finally, we noted a statistically significant increase in all plasma alpha-ketoacids except alpha-keto-beta-methylvaleric acid in PBC patients.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1993

Pallidonigroluysian degeneration with iron deposition: a study of three autopsy cases.

In the basal ganglia of three autopsy cases of pallidonigroluysian degeneration, we found marked iron deposition, a finding which has not been mentioned previously in the literature. Besides severe astrogliosis and neuronal loss in the pallidum, Luysian body and nigra, granular deposits of brown pigments were found in the neuropil, microglias, oligodendrocytes and astrocytes in three such the nuclei and the striatum. These brown pigments proved histochemically to be iron. Our histochemical semiquantitative study showed a significantly stronger reaction for iron in the degenerated nuclei in these three cases than in control cases comprising non-degenerative and the other degenerative diseases. Quantitative study with inductively coupled emission spectrometry also demonstrated a markedly higher iron content in the globus pallidus and the striatum in comparison with the control cases. The possibility is discussed that iron deposition plays a role in generating the lesions of pallidonigroluysian degeneration.

Adult↗
PubMed1993

Congenital frontal bone defect with intact overlying scalp.

An unusual case of a congenital frontal bone defect with intact overlying scalp and intact underlying dura mater is reported. Although spontaneous healing by the intact underlying dura mater by regeneration was expected, it did not occur. Cranioplasty was done for protective and cosmetic purposes. A review of the literature of congenital skull defects shows that spontaneous regeneration does not occur in this rare anomaly.

Child, Preschool↗
PubMed1993

Nonlinear mixed effect modeling of the pharmacodynamics of natriuretic peptides in rats.

Natriuretic peptides have not only natriuretic/diuretic but also hypotensive activities, and the decreased renal perfusion caused by the excessive hypotension is known to attenuate the diuretic actions. The present study was designed to examine the relationship between the dosing (intravenous constant infusion) rates and the diuretic actions of alpha-rat atrial natriuretic peptide (alpha-rANP) and rat brain natriuretic peptide (rBNP) in rats, and population (nonlinear mixed effect model) analysis was applied to these complicated diuretic actions. The intrinsic diuretic activities of alpha-rANP and rBNP could be analyzed, and the effects of blood pressure, heart rate, and also inhibition of degradation enzyme on the diuresis of natriuretic peptides were estimated simultaneously. The population analysis was useful for analyzing such pharmacodynamic data for which the individual analysis could not be applied easily.

Animals↗
PubMed1993

Roles of histamine and diamine oxidase in mucosa of rat small intestine after ischemia-reperfusion.

To examine the roles of histamine and diamine oxidase in the intestine after ischemia-reperfusion, we measured histamine content, diamine oxidase activity, and ornithine decarboxylase activity in rat intestinal mucosa 6 hr following various periods of ischemia. In addition, mortality rates of rats after various periods of ischemia were observed. The superior mesenteric artery was occluded for 15, 30, or 60 min. Ornithine decarboxylase activity increased in the 15-, 30-, and 60-min ischemic groups compared to the sham-operated control group. In the prolonged ischemic group (60-min ischemia), both histamine concentration and diamine oxidase activity in the mucosa decreased, contributing to an increase in circulating histamine. In the 60-min ischemic group, the mortality rate of rats was 25%, which was significantly larger than the control groups. Pretreatment with aminoguanidine, which suppressed diamine oxidase activity, increased the mortality rate. These results indicate that histamine released from the intestinal mucosa has a harmful effect on rats, and diamine oxidase activity plays an important role when the small intestine is subjected to prolonged period of ischemia.

Amine Oxidase (Copper-Containing)↗
PubMed1993

Heparin and dibutyryl cAMP modulate gene expression in stimulated human saphenous vein smooth muscle cells.

Increased expression of basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) A chain, and tissue plasminogen activator (tPA) by smooth muscle cells (SMC) has been postulated to mediate the progression of intimal hyperplasia. We tested whether heparin would suppress the expression of these genes in stimulated human saphenous vein SMC. Quiescent cultured human saphenous vein SMC were stimulated for 4 h with heat-inactivated fetal bovine serum (10% by vol) in the presence or absence of heparin (1 to 250 micrograms/ml). Heparin (50 micrograms/ml) attenuated the induction by serum of bFGF mRNA, tPA mRNA, and tPA secretion. Nonanticoagulant heparin also attenuated serum induction of bFGF and tPA mRNA levels. To further study the role of second messenger signaling, a more specific mode of SMC stimulation was used with thrombin (3 U/ml) in the presence or absence of dibutyryl cyclic AMP (Bu2-cAMP; 0.5 mM). In contrast to heparin, which had no effect on PDGF expression, Bu2-cAMP decreased the induction by thrombin of PDGF-A chain mRNA levels. In thrombin-stimulated SMC, Bu2-cAMP significantly decreased secretion of PDGF-AA protein. Thrombin, however, caused an increase in bFGF mRNA levels which was potentiated by Bu2-cAMP with associated potentiation by Bu2-cAMP of intracellular bFGF protein levels. The induction of tPA mRNA and tPA secretion by thrombin was sharply blocked by Bu2-cAMP. These results suggest that heparin reduces intimal hyperplasia at least partly via partial inhibition of SMC gene expression.

Bucladesine↗
PubMed1993

Extravascular lung water measured with 99mTc-RBC and 99mTc-DTPA is increased in left-sided heart failure.

Extravascular lung water (EVLW) was quantitatively measured in 81 patients consisting of 10 subjects with normal cardiac function and 71 patients with left-sided heart diseases, using 99mTc-RBC as a non-diffusible indicator and 99mTc-DTPA as a diffusible indicator in the equilibrium phase. EVLW averaged 3.0 +/- 1.4 (ml/kg, mean +/- SD) in subjects with normal cardiac function (n = 10), 4.3 +/- 1.7 in New York Heart Association functional class I patients (n = 30), 4.8 +/- 2.4 in NYHA functional class II patients (n = 33) and 9.4 +/- 5.4 in NYHA functional class III (n = 8) patients. EVLW was greater in NYHA class III than in normal controls or NYHA classes I or II (p < 0.01). Lung thermal volume (LTV) was also measured in 31 of the 81 patients using a double indicator dilution technique with sodium and heat. LTV averaged 6.0 +/- 1.2 (ml/kg) in normal subjects (n = 4), 8.6 +/- 2.0 in NYHA functional class I patients (n = 11), 9.7 +/- 3.0 in NYHA functional class II patients (n = 13), and 15.9 +/- 8.2 in NYHA functional class III patients (n = 3). The correlation between EVLW and LTV was significant (EVLW = 0.79 x LTV - 72.8, r = 0.80, p < 0.01). There were significant differences in EVLW/LTV ratio between NYHA class III (0.93 +/- 0.16) and NYHA class I (0.62 +/- 0.22). Thus, it was shown that EVLW was increased in left-sided heart failure and that LTV overestimated the EVLW.

Aged↗
PubMed1993

Long-term palliation after systemic-to-pulmonary artery shunt using an internal mammary artery.

We report the long-term results after systemic-to-pulmonary artery shunts using the internal mammary arteries in 2 patients. The systemic-to-pulmonary artery shunts using the internal mammary arteries were created in 2 children. Both of them are doing well 11 years and 7 years after operation. This procedure could be a reasonable alternative to classic Blalock-Taussig shunt for patients with diminutive pulmonary arteries as it offered good long-term palliation.

Angiography↗
PubMed1993

Specificity and molecular properties of penicillolysin, a metalloproteinase from Penicillium citrinum.

The specificity and mode of action of penicillolysin, a metalloproteinase from Penicillium citrinum, were investigated with several bioactive-oligopeptides. The enzyme showed a high affinity toward the Pro-X (X = Gln, Lys, Leu or Arg) bonds of substance P, dynorphin A (1-13), neurotensin and chicken brain pentapeptide, and the R-R bonds in dynorphin A and neurotensin. Preferential cleavage of bonds by the enzyme with hydrophobic amino acid residues at the P1 position were observed on the peptides used. The specificity of penicillolysin differs from that of other metalloproteinases. The M(r) and pI were determined as 18,000 and 9.6, respectively. The first 50 amino acids in the N-terminal region were TKETCSNASRKSALEKALSNTVKLANAAATAARSGSASKFSEYEKTTSSS. CD spectra on the hollo- and apo-enzymes of penicillolysin were studied.

Amino Acid Sequence↗