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Biomedical subjects

H Inoue

Publications and source records attributed to H Inoue.

At least 271 records · Page 15Linked to original sources
PubMed2000

Risk factors for thromboembolism in patients with paroxysmal atrial fibrillation.

There is some controversy concerning which clinical characteristics predict thromboembolism and whether treatment with class I antiarrhythmic drugs reduces thromboembolim in patients with paroxysmal atrial fibrillation (AF). This retrospective, multicenter study was undertaken to determine risk factor or factors for thromboembolism in patients with paroxysmal AF. Seven hundred forty patients with paroxysmal AF (mean age 56 years) without prior thromboembolic events were followed retrospectively. Cerebral thromboembolism, including transient ischemic attack and embolism of peripheral arteries, were selected as primary end points. Independent risk factors were determined with multivariate analysis, and event-free survival curves were estimated. During 3.4-year follow-up period, primary end points occurred in 55 patients (2.2% per year). Patients with thromboembolism had a higher prevalence of underlying heart disease (p <0.01), less frequent treatment with antiarrhythmic drugs (p <0.01), and received diuretics more often (p <0.01) compared with patients without thromboembolism. Age (>/=65 years, RR 3.33, p = 0.0001) and gender (male, RR = 2, p = 0.0291) emerged as predictors of thromboembolism by multivariate analysis with Cox's proportional hazard model. Treatment with antiarrhythmic drugs (RR = 0.57, p = 0.0578) and aspirin (RR = 0.52, p = 0.1094) showed trends toward reducing thromboembolic risks. It is suggested that elderly men (>/=65 years) with paroxysmal AF are at risk for thromboembolism, but the risk tended to be reduced by treatment with antiarrhythmic drugs and aspirin.

Atrial Fibrillation↗
PubMed2000

Expression of connective tissue growth factor in cartilaginous tumors.

BACKGROUND: Connective tissue growth factor (CTGF) predominantly is expressed in hypertrophic chondrocytes and its specific receptors are demonstrated on chondrocytic cells. Therefore, CTGF may be involved in the proliferation and/or differentiation of cartilage cells. In the current study, CTGF expression was examined both in chondrosarcoma and enchondroma to clarify the relation between the expression of CTGF and the grade of malignancy. METHODS: The expression of CTGF and proliferating cell nuclear antigen (PCNA) were analyzed immunohistochemically in 34 cartilaginous tumor specimens. Eighteen tumors were determined to be chondrosarcoma including 8 Grade 1 tumors, 6 Grade 2 tumors, and 4 Grade 3 tumors. The percentage of CTGF positive and PCNA positive cells was quantified using at least 500 cells. RESULTS: CTGF was expressed in 70.1% of enchondroma cells, 84.0% of Grade 1 chondrosarcoma cells, 53.7% of Grade 2 tumor cells, and 26.8% of Grade 3 tumor cells (rho = -0.501; P = 0.0053). In chondrosarcoma cases, CTGF expression was correlated closely with tumor grade (rho = -0.920; P = 0.0001). There was a strong correlation between PCNA expression and tumor grade (rho = 0.907; P < 0.0001) and a strong negative correlation between CTGF and PCNA expression (rho = -0.493; P = 0.0061). In chondrosarcoma cases, patients with high expression of CTGF (>/= 30%) showed higher overall survival compared with those with low expression (< 30%) (P = 0.004). CONCLUSIONS: The current study revealed a correlation between the histologic grade of chondrosarcoma and prognosis, and the concomitant association between CTGF immunostaining and tumor grade and prognosis. Therefore, immunohistochemical staining with CTGF is a useful procedure for assessing the tumor grade and clinical course in patients with chondrosarcoma.

Adolescent↗
PubMed2000

Direct effects of methamphetamine on hypertrophy and microtubules in cultured adult rat ventricular myocytes.

Morphological alterations occasionally found in the myocardium of methamphetamine (MAP) abusers include hypertrophy, atrophy, disarrangement of myofibrils and fibrosis. These cardiac alterations have been thought to be due to an indirect action of MAP via catecholamines released by MAP administration. However, the direct effect of MAP on cardiomyocytes is not clear. In previous studies, we showed that cell size of isolated adult rat ventricular cardiomyocytes (ARCs) exposed to MAP was larger than that of untreated cells in culture supplemented with 10% fetal calf serum (FCS). In this study, to determine further the direct effect of MAP on cardiomyocytes, cultured ARCs were exposed to 0.05, 0.1 and 0.5 mM MAP for 7 days in culture medium without FCS following 6-day normal culture in medium containing FCS. Myocyte size was measured and microtubular (MT) structures which were associated with functional disorder of hearts were immunohistochemically observed using confocal microscopy. The size in treated ARCs significantly increased time- and dose-dependently as compared with untreated cells, but it decreased 7 days after exposure to 0.5 mM MAP. The increases in cell size, however, were lower than that in serum-supplemented cultures. MT structures in intact ARCs appeared as a filamentous network throughout the cytoplasm and around the nucleus. MAP exposure for 3 days promoted MT assembly, but in 7-day treated cells, MT and actin structures were injured. These results suggested that MAP directly induced cellular hypertrophy and might lead to cardiac functional disorder.

Amphetamine-Related Disorders↗
PubMed2000

Screening and determination of benzodiazepines in whole blood using solid-phase extraction and gas chromatography/mass spectrometry.

Benzodiazepines are one of the most widely prescribed drugs for the treatment of a wide spectrum of clinical disorders. They are used as anticonvulsants, anxiolytics, hypnotics or muscle relaxants with different duration of action. In this paper, a simple and sensitive method for the determination of benzodiazepines in whole blood using solid-phase extraction and gas chromatography/mass spectrometry (GC/MS) is described. The drugs spiked in whole blood were extracted with an Oasis HLB solid-phase extraction cartridge (Waters), which contains a copolymer designed to have a hydrophilic-lipophilic balance. GC/MS analysis was performed using a Shimadzu QP-5000 equipped with a BPX5 capillary column (15 mx0.32 mm I.D., film thickness 0.25 microm, SGE). Nineteen benzodiazepines and two thienodiazepines were well separated from each other on their SIM chromatograms and also on the TIC with the exception of oxazolam to cloxazolam separation. The blank extract from whole blood gave no peaks that interfered with all benzodiazepines and thienodiazepines on the chromatogram. The calibration curves for selected benzodiazepines with fludiazepam as an internal standard showed excellent linearity over the concentration range 5-500 ng/ml blood with a correlation coefficients of >0.995. The detection limits ranged from 0.2 to 20 ng/ml blood. The method is simple and sensitive for the determination of benzodiazepines in whole blood and seems to be useful in the practice of forensic science.

Anti-Anxiety Agents↗
PubMed2000

Cyclooxygenase-2 participates in the late phase of airway hyperresponsiveness after ozone exposure in guinea pigs.

We examined the role of cyclooxygenase in airway hyperresponsiveness and inflammation after ozone exposure in guinea pigs using a non-selective (indomethacin) and a selective (JTE-522) cyclooxygenase-2 inhibitor. Spontaneously breathing guinea pigs were exposed to ozone (3 ppm) for 2 h after treatment with vehicle, indomethacin (10 mg/kg) or JTE-522 (10 mg/kg). Airway responsiveness to inhaled histamine (PC(200)) and bronchoalveolar lavage were assessed before, immediately and 5 h after ozone exposure. Ozone caused a significant airway hyperresponsiveness immediately after exposure, which persisted after 5 h. Neither JTE-522 nor indomethacin affected airway hyperresponsiveness immediately after ozone exposure, but significantly attenuated airway hyperresponsiveness 5 h after exposure, suggesting that cyclooxygenase-2 may participate in the late phase of airway hyperresponsiveness but not in the early phase. Ozone caused a significant increase in the concentration of prostaglandin E(2) and thromboxane B(2) in bronchoalveolar lavage fluid immediately after exposure, which decreased to the basal level 5 h after exposure. This increase in prostaglandin E(2) and thromboxane B(2) was significantly inhibited by JTE-522. An expression of cyclooxygenase-2 was detected not only after ozone exposure but also before, and there was no difference in the number of cyclooxygenase-2-positive cells at any time point. An exogenously applied thromboxane A(2) mimetic, U-46619 (10(-5) M), induced airway hyperresponsiveness 5 h after inhalation, but not immediately or 3 h after inhalation. These data suggest that cyclooxygenase-2 may be constitutively expressed before ozone exposure in guinea pig airway and may synthesize prostaglandin E(2) and thromboxane A(2) transiently under ozone stimulation and that thromboxane A(2) may, in turn, induce the late phase of airway hyperresponsiveness.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2000

Feedback control of cyclooxygenase-2 expression through PPARgamma.

Cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandins (PG), plays a key role in inflammation, tumorigenesis, development, and circulatory homeostasis. The PGD(2) metabolite 15-deoxy-Delta(12, 14) PGJ(2) (15d-PGJ(2)) was identified as a potent natural ligand for the peroxisome proliferator-activated receptor-gamma (PPARgamma). PPARgamma expressed in macrophages has been postulated as a negative regulator of inflammation and a positive regulator of differentiation into foam cell associated with atherogenesis. Here, we show that 15d-PGJ(2) suppresses the lipopolysaccharide (LPS)-induced expression of COX-2 in the macrophage-like differentiated U937 cells but not in vascular endothelial cells. PPARgamma mRNA abundantly expressed in the U937 cells, not in the endothelial cells, is down-regulated by LPS. In contrast, LPS up-regulates mRNA for the glucocorticoid receptor which ligand anti-inflammatory steroid dexamethasone (DEX) strongly suppresses the LPS-induced expression of COX-2, although both 15d-PGJ(2) and DEX suppressed COX-2 promoter activity by interfering with the NF-kappaB signaling pathway. Transfection of a PPARgamma expression vector into the endothelial cells acquires this suppressive regulation of COX-2 gene by 15d-PGJ(2) but not by DEX. A selective COX-2 inhibitor, NS-398, inhibits production of PGD(2) in the U937 cells. Taking these findings together, we propose that expression of COX-2 is regulated by a negative feedback loop mediated through PPARgamma, which makes possible a dynamic production of PG, especially in macrophages, and may be attributed to various expression patterns and physiological functions of COX-2.

Animals↗
PubMed2000

Identification of a protein phosphorylated by cAMP-dependent protein kinase in drosophila brain.

In the present study, we examined the effects of reagents that elevate cAMP concentration on protein phosphorylation in Drosophila brain cells. Application of forskolin or dopamine to brain cells that were prelabeled with (32)Pi enhanced phosphorylation of a 25-kDa protein (p25a). To identify p25a, we isolated the protein, and partial amino acid sequences were analyzed. Database searches showed that p25a is a J-domain protein, dJDP that contains the J-domain found in the DnaJ (heat shock protein 40) family of molecular chaperones.

Animals↗
PubMed2000

Effect of dimethylthiourea, a hydroxyl radical scavenger, on cigarette smoke-induced bronchoconstriction in guinea pigs.

Cigarette smoke exposure causes bronchoconstriction in guinea pigs by stimulating cholinergic and excitatory nonadrenergic, noncholinergic (eNANC)-nerves in vagus system. The aim of this study is to elucidate the role of hydroxyl radical (OH(-)), contained in cigarette smoke, in bronchoconstriction. Anaesthetized animals were exposed to 80 puffs of smoke for 4 min. Pretreatment with dimethylthiourea, a OH(-) scavenger, significantly inhibited cigarette smoke-induced bronchoconstriction. To investigate its site of action, effects of dimethylthiourea were examined on vagally mediated bronchcoconstriction by electrical stimulation and on the bronchoconstriction by intravenous acetylcholine and neurokinin-A. Dimethylthiourea did not inhibit bronchoconstriction evoked by vagal stimulation, acetylcholine or neurokinin-A. These results suggest that dimethylthiourea inhibits cigarette smoke-induced bronchoconstriction by scavenging the smoke-derived OH(-), but not by inhibiting airway nerve function.

Acetylcholine↗
PubMed2000

Analysis of citrulline in rat brain tissue after perfusion with haloperidol by liquid chromatography-mass spectrometry.

We have investigated the potential of high-performance liquid chromatography (HPLC) coupled to mass spectrometry (MS) to determine enrichments of citrulline as a marker for in vivo nitric oxide (NO) production in brain tissue. The analysis of citrulline as the butyl ester derivative was evaluated using two types of ionization: electron spray ionization (ESI) and atmospheric pressure chemical ionization (APCI). APCI-MS appeared to be more suitable for determination of citrulline than ESI-MS, because the ion intensity of the protonated molecule ion [M+H]+, m/z 232, of citrulline in the former was about twelve times higher than in the latter. The chromatography was carried out on a reversed C8 column with the mobile phase consisting of 15% acetonitrile: 85% H2O: 0.2% acetic acid (v/v). The calibration curve had good linearity within the concentration range investigated (5 ng to 500 ng/ml). The limit of determination was estimated to be ca. 1 ng/ml of standard solution. The method was applied to the analysis of citrulline in the brain dialysate obtained from rat after perfusion of the striatum with haloperidol (HP, 0.1 mM). It is concluded that APCI-MS in combination with HPLC can be successfully applied to determination of citrulline in brain tissue, thus providing a useful tool for assessment of in vivo NO production.

Animals↗
PubMed2000

Identification of a glutamic acid and an aspartic acid residue essential for catalytic activity of aspergillopepsin II, a non-pepsin type acid proteinase.

Aspergillopepsin II from Aspergillus niger var. macrosporus is a non-pepsin type or pepstatin-insensitive acid proteinase. To identify the catalytic residues of the enzyme, all acidic residues that are conserved in the homologous proteinases of family A4 were replaced with Asn, Gln, or Ala using site-directed mutagenesis. The wild-type and mutant pro-enzymes were heterologously expressed in Escherichia coli and refolded in vitro. The wild-type pro-enzyme was shown to be processed into a two-chain active enzyme under acidic conditions. Most of the recombinant mutant pro-enzymes showed significant activity under acidic conditions because of autocatalytic activation except for the D123N, D123A, E219Q, and E219A mutants. The D123A, E219Q, and E219A mutants showed neither enzymatic activity nor autoprocessing activity under acidic conditions. The circular dichroism spectra of the mutant pro- and mature enzymes were essentially the same as those of the wild-type pro- and mature enzyme, respectively, indicating that the mutant pro-enzymes were correctly folded. In addition, two single and one double mutant pro-enzyme, D123E, E219D, and D123E/E219D, did not show enzymatic activity under acidic conditions. Taken together, Glu-219 and Asp-123 are deduced to be the catalytic residues of aspergillopepsin II.

Amino Acid Sequence↗
PubMed2000

Activation of serum response factor in the depolarization induction of Egr-1 transcription in pancreatic islet beta-cells.

The results of the current studies define the major elements whereby glucose metabolism in islet beta-cells leads to transcriptional activation of an early response gene in insulinoma cell lines and in rat islets. Glucose stimulation (2-20 mm) resulted in a 4-fold increase in Egr-1 mRNA at 30 min, as did the depolarizing agents KCl and tolbutamide. This response was inhibited by diazoxide and EGTA, indicating that beta-cell depolarization and Ca(2+) influx, respectively, are essential. Pharmacological inhibition of the Egr-1 induction by H89 (48%) and calmidazolium (35%), but not by mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1 and 2 or phosphatidylinositol 3-kinase inhibitors, implied that protein kinase A and Ca(2+)/calmodulin pathways are involved. Deletion mapping of the Egr-1 promoter revealed that the proximal -198 base pairs containing two serum response elements (SREs) and one cAMP-response element retained the depolarization response. Depolarization resulted in phosphorylation of cAMP-response element-binding protein, yet partial inhibition by a dominant negative cAMP-response element-binding protein, along with a robust response of a cAMP-response element-mutated Egr-1 promoter suggested the presence of a second Ca(2+)-responsive element. Depolarization activation of 5XSRE-LUC and serum response factor (SRF)-GAL4 constructs, along with activation of SRF-GAL4 by co-transfection with constitutively active calmodulin kinase IV and protein kinase A, and binding of Ser(103)-phosphorylated SRF in nuclear extracts, indicated that the SRE.SRF complexes contribute to the Ca(2+)-mediated transcriptional regulation of Egr-1. The results of the current experiments demonstrate for the first time SRE-dependent transcription and the role of SRF, a transcription factor known to be a major component of growth responses, in glucose-mediated transcriptional regulation in insulinoma cells.

Animals↗
PubMed2000

Ru(II)- and Pt(II)-catalyzed cycloisomerization of omega-aryl-1-alkynes. Generation Of carbocationic species from alkynes and transition metal halides and its interception by an aromatic ring

The treatment of aryl-1-alkynes, such as 4-aryl-1-butyne, 5-aryl-1-pentyne, and 6-aryl-1-hexyne, with catalytic amounts of transition metal chlorides, such as PtCl(2) and [RuCl(2)(CO)(3)](2), at 80 degrees C in toluene results in cycloisomerization to give dihydronaphthalenes or dihydrobenzocycloheptenes, in which the cyclization mode is dependent on the length of the tethers. The reaction is limited to substrates containing terminal alkynes. A key step of the reaction is the intramolecular interception by an aromatic ring of the vinylmetal complex 2, which contains a cation center at the beta-position, generated from the electrophilic addition of transition metal halides toward an alkyne. The more electron-rich aryl systems are more reactive.

Journal Article↗
PubMed2000

Noncompetitive, reversible inhibition of aminoacylase-1 by a series of L-alpha-hydroxyl and L-alpha-fluoro fatty acids: ligand specificity of aspergillus oryzae and porcine kidney enzymes.

L-lactate and L-beta-phenyllactate have been identified in the culture broth of Streptomyces sp. KY-11 as reversible noncompetitive inhibitors of Aspergillus oryzae aminoacylase-1 and porcine kidney aminoacylase I. A series of alpha-hydroxyl acids (DL-R-CH(OH)-COOH, R = Et, n-pro, n-butyl, n-pentyl, n-hexyl) also inhibited the two enzymes in reversible noncompetitive kinetics, and the inhibition potency (-log K(i)) increased with the increased hydrophobicity of the R group. The two eukaryotic enzymes showed distinct preferences to the ligand alpha-alkyl group, and the fungus enzyme was inhibited by L-beta-phenyllactate (R = benzyl) 10(3)-fold more potently than the mammalian enzyme. L-alpha-Fluoro-beta-phenyl-propionate and its D-isomer were used to show that the L-configuration of the alpha-substituent was important for potent inhibition of both the enzymes. The fungus aminoacylase-1 steeply decreased the affinity to alpha-fluoro- and alpha-hydroxy-n-caproate as pH was raised from 7 to 11, whereas the mammalian enzyme retained the affinity to these ligands under alkaline conditions. These results suggest that A. oryzae aminoacylase-1 has an acidic residue that interacts with -OH or -F, while the mammalian enzyme would have a basic residue that recognizes the alpha-substituents.

Alkylation↗
PubMed2000

Cigarette smoking, CYP1A1 MspI and GSTM1 genotypes, and colorectal adenomas.

Cigarette smoking has been related to increased risk of colorectal adenomas, but the underlying mechanisms are unknown. Genetic polymorphisms are known for enzymes involved in the activation of polycyclic aromatic hydrocarbons and other tobacco-related carcinogens. Polycyclic aromatic hydrocarbons are activated by cytochrome P4501A1 (CYP1A1) and detoxified by glutathione S-transferases. We investigated the relation of CYP1A1 MspI and GSTM1 genotypes to the risk of colorectal adenomas with special reference to interaction with cigarette smoking among 205 cases of colorectal adenomas and 220 controls with normal total colonoscopy in a male Japanese population. Cigarette smoking was strongly associated with increased risk of colorectal adenomas. Overall, neither the CYP1A1 MspI genotype nor the GSTM1 genotype was related to colorectal adenomas. A significant trend for increased risk of colorectal adenomas associated with smoking was observed for each of the CYP1A1 MspI genotypes, and the increasing trends did not differ by MspI genotype. The positive association between smoking and colorectal adenomas did not vary much with GSTM1 genotypes. Among former and current smokers, adenoma risk did not differ according to the combination of CYP1A1 MspI and GSTM1 genotypes. CYP1A1 MspI and GSTM1 genotypes do not seem to modify the risk of colorectal adenomas associated with cigarette smoking.

Adenoma↗
PubMed2000

Dysfunction of human Rad18 results in defective postreplication repair and hypersensitivity to multiple mutagens.

Postreplication repair functions in gap-filling of a daughter strand on replication of damaged DNA. The yeast Saccharomyces cerevisiae Rad18 protein plays a pivotal role in the process together with the Rad6 protein. Here, we have cloned a human homologue of RAD18, hRAD18. It maps on chromosome 3p24-25, where deletions are often found in lung, breast, ovary, and testis cancers. In vivo, hRad18 protein binds to hHR6 protein through a conserved ring-finger motif. Stable transformants with hRad18 mutated in this motif become sensitive to UV, methyl methanesulfonate, and mitomycin C, and are defective in the replication of UV-damaged DNA. Thus, hRAD18 is a functional homologue of RAD18.

Amino Acid Sequence↗
PubMed2000

Down-regulation of drs mRNA in human colon adenocarcinomas.

We have previously reported that the drs gene, whose mRNA expression is down-regulated by retroviral oncogenes such as v-src and v-K-ras, has the ability to suppress transformation by v-src and v-K-ras in the rat cell line F2408. We have also isolated a human homolog of this gene (h-drs) and shown that expression of h-drs mRNA is markedly reduced in a variety of human cancer cell lines, including those of carcinomas of the colon, bladder, and ovary, suggesting that down-regulation of drs mRNA is correlated with the development of human cancers. To clarify the correlation between down-regulation of the drs gene and malignant tumor formation in human cancer tissues, we examined expression of drs mRNA in human normal tissues, colon adenoma, and adenocarcinoma tissues by in situ hybridization. Expression of drs mRNA was detected in most normal tissues tested, including those of the colon, bladder, and ovary. However, drs mRNA was hardly expressed in any of the colon adenocarcinoma tissues examined. Northern blot analyses confirmed these results. Neither gross deletion nor re-arrangement of the drs genome was detected by Southern blot hybridization in these adenocarcinoma tissues. drs mRNA was significantly expressed in colon adenoma with mild atypia but down-regulated in adenomas with moderate atypia and focal carcinoma. Our results indicate that down-regulation of drs mRNA is closely correlated with development of colon adenocarcinoma, suggesting a tumor-suppressor function of the drs gene in human cancers.

Adenocarcinoma↗
PubMed2000

Exercise-induced negative U waves in precordial leads as a marker of viable myocardium in patients with recent anterior myocardial infarction.

Patients with recent anterior myocardial infarction and a significant stenosis in the left anterior descending coronary artery were divided into two groups according to the presence (Group A, n=24) or absence (Group B, n=77) of negative U waves in the precordial leads during exercise stress test to compare the coronary arteriographic findings. Both total occlusion of the left anterior descending coronary artery (79% vs. 31%, P<0.01)) and good (index=2, 3) collateral circulation to the territory of this artery (92% vs. 36%, P<0.01) were observed more often in group A than in group B. In order to determine whether detection of exercise-induced negative U waves in precordial leads can predict the presence of viable myocardium, the 56 patients (20 of group A and 36 of group B) with total or subtotal occlusion of the left anterior descending coronary artery were studied further. The coronary arteriographic and exercise 201Tl scintigraphic findings were compared between the groups. Good collateral circulation to the territory of this artery was observed significantly (P<0.05) more often in group A (100%) than in group B (61%). Patients with multivessel disease were significantly (P<0.05) more prevalent in group A (70%) than in group B (33%). The incidence of a significant partial redistribution in the anteroseptal area in the 20Tl images 4 h after exercise was significantly (P<0.01) higher in group A (85%) than in group B (39%). In 29 patients with anterior Q-wave myocardial infarction and exercise-induced ST elevation in precordial leads, a significant 201Tl redistribution in the anteroseptal area was observed in 8 (80%) of 10 patients of group A in contrast to only 4 (21%, P<0.05) of 19 in group B. In the diagnosis of the viability associated with 201Tl redistribution in the anteroseptal area by the finding of exercise-induced negative U waves, the sensitivity was 67% and the specificity was 88% in these patients. We conclude that exercise-induced negative U waves in precordial leads are a convenient and specific marker for the presence of viable myocardium in patients with recent anterior myocardial infarction.

Collateral Circulation↗