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S Matsui

Publications and source records attributed to S Matsui.

At least 163 records · Page 9Linked to original sources
PubMed1995

Isolation of a full-length cDNA clone for human GTP cyclohydrolase I type 1 from pheochromocytoma.

Although the existence of three different cDNA forms of human GTP cyclohydrolase I (GCH I) have been reported (Togari et al., 1992), the full-length sequence of any human GCH I cDNA involving poly (A) tail has not yet been documented. In the present study, we first isolated a full-length cDNA clone encoding human GCH I type 1 from human pheochromocytoma cDNA library. The length of the cDNA insert was 2,921 base pairs including poly (A) tail. RNA blot analysis showed a single mRNA species of 4.0 kb in human pheochromocytoma tissue.

Amino Acid Sequence↗
PubMed1995

Assessment of working skeletal muscle oxygenation in patients with chronic heart failure.

Patients with chronic heart failure (CHF) are frequently limited by muscle fatigue resulting from impaired skeletal muscle blood flow. Accordingly, we assessed working skeletal muscle oxygenation in such patients using near-infrared (NIR) spectroscopy. Nine normal subjects (mean age 52 years) and 12 patients with CHF (mean age 60 years) were studied. NIR spectroscopy was used to monitor relative changes in oxygenated hemoglobin (Hb) and myoglobin (Mb) (oxy Hb/Mb), deoxygenated Hb and Mb (deoxy Hb/Mb), and total (oxy + deoxy) Hb and Mb (total Hb/Mb) contents in the vastus lateralis muscle at rest, during warm-up (0 W, 30 cycles/min for 3 min), incremental maximal supine bicycle exercise (ramp protocol, 15 W/min, 50 cycles/min), and recovery. At peak exercise the patients exhibited reduced heart rate, systolic blood pressure, peak exercise oxygen consumption (VO2; 15 +/- 3.0 ml/kg/min vs 32 +/- 8.5 ml/kg/min), and workload (99 +/- 23.4 W vs 183 +/- 68.4 W) as compared with the normal subjects. The respiratory quotient was comparable in both groups. In the normal subjects, oxy Hb/Mb was increased from the warm-up period to the early phase of exercise, followed by a progressive decrease to peak exercise. In the recovery phase, oxy Hb/Mb was increased abruptly. For these patients, change in oxy Hb/Mb followed a pattern similar to that seen in normal subjects, and oxy Hb/Mb was decreased earlier in contrast to that in the normal subjects. There was a significant difference in the change of oxy Hb/Mb during warm-up, early phase exercise, and recovery between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Test↗
PubMed1995

Effect of epidermal growth factor on cadherin-mediated adhesion in a human oesophageal cancer cell line.

Epidermal growth factor (EGF) mediates many pleiotrophic biological effects, one of which is alteration of cellular morphology. In the present study, we examine the possibility that this alteration in cell morphology is caused in part by the dysfunction of cadherin-mediated cell-cell adhesion using the human oesophageal cancer cell line TE-2R, which expresses E-cadherin and EGF receptor. In the presence of EGF, TE-2R changed its shape from round to fibroblastic and its colony formation from compact to sparse. Vanadate, a tyrosine phosphatase inhibitor, further potentiated the EGF response, whereas herbimycin A, a tyrosine kinase inhibitor, interfered with it. Moreover, EGF enabled the cells to invade in organotypic raft culture. These phenomena were accompanied not by decreased expression of the E-cadherin molecule but by a change in its localisation from the lateral adhesion site to the whole cell surface. Both alpha- and beta-catenin, cadherin-binding proteins, were also expressed at the same level throughout these morphological changes. Finally, we examined tyrosine phosphorylation of E-cadherin and alpha- and beta-catenin, and observed tyrosine phosphorylation of beta-catenin induced by EGF. These results suggest that EGF counteracts E-cadherin-mediated junctional assembly through phosphorylation of beta-catenin and modulates tumour cell behaviour to a more aggressive phenotype.

Benzoquinones↗
PubMed1995

Molecular analysis of mutations induced by 2-chloroacetaldehyde, the ultimate carcinogenic form of vinyl chloride, in human cells using shuttle vectors.

Vinyl chloride (VC) is a carcinogen associated with human and animal cancers. The ultimate carcinogenic form of VC, 2-chloroacetaldehyde (CAA), has been suspected to be mutagenic and we confirmed the mutagenicity of CAA using a modified shuttle vector plasmid. Base sequence analyses of 109 mutant plasmids with mutations in the supF gene, which were treated with CAA and propagated in the cultured human cells, revealed that more than half of the single base substitutions were G:C to A:T transitions with eight hotspots. The majority of the mutations involving G:C base pairs were in 5'-AAGG-3' or 5'-CCTT-3' sequences suggesting that these sequences are the main targets of mutagenesis caused by CAA.

Acetaldehyde↗
PubMed1995

Beneficial effect of amrinone on murine cardiac allograft survival.

Amrinone is a non-glycoside positive inotropic agent with an inhibitory effect on a cyclic adenosine monophosphate (AMP) phosphodiesterase isoenzyme. In the present study, we examined the immunosuppressive action of amrinone, since several other cyclic AMP-elevating agents have been shown to suppress T lymphocyte activation. First, the in vivo effects of amrinone were investigated. Oral amrinone treatment, at 40 mg/kg per day, significantly prolonged median cardiac allograft survival compared with non-treated controls (22.0 days versus 10.5 days, P < 0.01) when DBA/2 mouse hearts (H-2d) were heterotopically transplanted into C57B1/6 mice (H-2b). Histopathological examination showed that there was less prominent cellular infiltration in the amrinone-treated than in the non-treated allografts. Plasma amrinone concentrations of mice after a single oral dose of 40 mg/kg were within the range of clinical relevance. To clarify the mechanism of action, in vitro studies were done. The generation of specific cytotoxic T lymphocytes after mixed lymphocyte culture was significantly suppressed by addition of amrinone to the culture medium at 5 micrograms/ml. The production of IL-2 and the interferon-gamma during mixed lymphocyte culture was also suppressed by amrinone at 5 micrograms/ml. However, the level of intracellular cyclic AMP in mouse splenic lymphocytes was not affected significantly by the same dose of amrinone. In conclusion, amrinone has immunosuppressive actions at the therapeutic doses, and it may be a beneficial agent for therapy against acute cardiac allograft rejection.

Amrinone↗
PubMed1995

Metabolic effects of glibenclamide in isolated rat hepatocytes in the absence of extracellular Ca2+.

We examined the metabolic effects of glibenclamide, a potent second-generation sulfonylurea, in isolated rat hepatocytes incubated in the absence of extracellular Ca2+. We first demonstrated in the present study that glibenclamide caused a significant increase in basal glucose release and lactate production without any modification of intracellular Ca2+ concentration or cAMP levels in isolated rat hepatocytes. Furthermore, glibenclamide inhibited the noradrenaline-induced increase in cAMP accumulation, while activation of glycogenolysis by noradrenaline was not suppressed by this agent. Our data indicate that glibenclamide exerts its metabolic effects independent of intracellular Ca2+ mobilization and cAMP accumulation.

Animals↗
PubMed1995

Dilated cardiomyopathy defines serum autoantibodies against G-protein-coupled cardiovascular receptors.

In order further to identify the prevalence of anti-receptor autoantibodies in the sera of patients with dilated cardiomyopathy (DCM), we attempted to detect autoantibodies against a series of G-protein-coupled cardiovascular receptors in a well-defined population of DCM patients from Japan. Peptides corresponding to the sequences of the second extracellular loops of the human beta 1 and beta 2 adrenoceptors, alpha 1 adrenoceptors, M2 muscarinic acetylcholine receptors and angiotensin II-1 (AT1) receptors were used as antigens in an enzyme immunoassay to screen the sera from patients with DCM (n = 28). Nine sera from patients with DCM (32%) and 2 sera from healthy subjects (9%) recognized the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor had autoantibody against the M2 receptor. However, no significantly high frequencies of autoantibodies against the beta 2 adrenoceptor, alpha 1 adrenoceptor and AT1 receptor were found in DCM patients. Our results demonstrate that a subgroup of patients with DCM have a specific spectrum of autoantibodies which are specifically directed against the second extracellular loops of the beta 1 adrenoceptors and M2 muscarinic receptors rather than other cardiovascular receptors.

Adult↗
PubMed1995

[Histopathological and immunohistochemical evaluation of lymph node metastasis in superficial esophageal cancer--with reference to the expression of E-cadherin and alpha-catenin].

We compared node-negative patients (13 cases) with node-positive patients (17 cases) with submucosal cancer of the esophagus, to assess the relationship between clinicopathological factors and lymph node metastasis. We also investigated the expression of E-cadherin, an intercellular adhesion molecule (27 cases), and alpha-catenin, an undercoat protein of adherence junction (16 cases) by immunohistochemical staining to evaluate the association between intercellular adhesiveness and lymph node metastasis in superficial esophageal cancer. There was no significant difference between the node-negative and node-positive groups in other clinicopathological factors and tumor size, while the frequency of lymphatic invasion in the node-positive group was statistically higher than that in the node-negative group (p < 0.05). The frequency of lymph node metastasis in 14 cases with preserved expression of E-cadherin was significantly lower than that in 13 cases with reduced or negative expression (7.1% vs. 46.2%: p < 0.05). Moreover, all three patients with negative expression of alpha-catenin had lymph node metastasis, while only one of 13 patients with preserved or reduced expression of alpha-catenin had lymph node metastasis (100% vs. 7.7%: p < 0.01). In conclusion, we have found that the evaluation of both E-cadherin and alpha-catenin expression might be of great value in predicting lymph node metastasis in superficial esophageal cancer.

Adult↗
PubMed1995

Detachment of desmosomes in a microcystic meningioma.

This report demonstrates the detachment of desmosomes in the microcystic area of a frontal convexity meningioma removed from a 69-year-old woman. Well-developed interdigitations of the tumor cell processes with numerous desmosomes and with narrow extracellular spaces were characteristic features of the solid area of the meningioma. By contrast, the microcystic area of the tumor had markedly distended extracellular spaces. Various stages in the separation of desmosomal attachments were seen in this area. The observed configurations ranged from the widening of opposing junctions to the formation of large cavities where hemidesmosome-like structures were evident. The latter lacked basal lamina, and are considered to represent a transition leading to the loss of desmosome, and thus involved in the enlargement of the extracellular space in microcystic meningiomas.

Aged↗
PubMed1994

Detection of the products of polymerase chain reaction by an ELISA system based on an ion sensitive field effect transistor.

An ELISA system was developed using a pH sensitive ISFET (pH-FET) as a detector, a pipette tip as a solid phase, and urease as a detecting enzyme. Double stranded PCR products with digoxigenin and biotin at both terminals were obtained by using digoxigenin- and biotin-labeled primers. 1 microliters of the PCR solution was directly introduced into the end part of a pipette tip coated with anti-digoxigenin antibody. Biotin-labeled PCR products captured at the solid phase were detected with avidin-urease, of which the activity was measured by a pH-FET in a pH-measuring cell containing urea solution. The assay was used to detect HTLV-I provirus gene integrated in the genome of a human MT-1 cell, and it was found that 100 pg of the genomic DNA of MT-1 cell was specifically detectable after 35 cycles of PCR. Also the detection limit of the present ELISA system itself was determined by using known amounts of purified PCR product labeled with digoxigenin and biotin, and it was found that 10 amol of the labeled DNA in 1 microliter of sample was detectable.

Base Sequence↗
PubMed1994

E-cadherin and alpha-catenin expression in human esophageal cancer.

Intercellular adhesion of the epithelial tissue is mainly regulated by the E-cadherin (E-cad) molecule. alpha-Catenin (alpha-cat) is one of the E-cad-associated cytoplasmic proteins that forms a linkage to the cytoskeleton and regulates E-cad function. To investigate the mechanism of dysfunction in cell-cell adhesion in cancerous tissues, we examined E-cad and alpha-cat expression by immunohistochemical staining on 46 human esophageal cancers using our specific monoclonal antibodies. By grading of E-cad and alpha-cat expression as uniformly positive (+), heterogeneous (+/-), or uniformly negative (-), the 46 tumors could be classified into 9 (20%) E-cad(+)/alpha-cat(+), 15 (33%) E-cad(+/-)/alpha-cat(+/-), 21 (46%) E-cad(+/-)/alpha-cat(-), and 1 (2%) E-cad(-)/alpha-cat(-). Twenty-five (54%) of the 46 tumors showed a similar expression of both molecules, while the other 21 tumors (46%) showed E-cad(+/-)/alpha-cat(-). Thus, although the expression of alpha-cat was significantly correlated with that of E-cad, in some tumors the reduction of alpha-cat was greater. Regarding the clinicopathological features, the reduction of alpha-cat expression, as well as that of E-cad, was significantly associated with tumor dedifferentiation, infiltrative growth, and lymph node metastasis (P < 0.01). Furthermore, the frequency of lymph node metastasis in E-cad(+/-)/alpha-cat(-) tumors was significantly higher (90%) than in E-cad(+)/alpha-cat(+) tumors (22%) (P < 0.01) or in E-cad(+/-)/alpha-cat(+/-) tumors (47%) (P < 0.05). These results suggest that not only E-cad but also alpha-cat are important regulators of intercellular adhesion and that alpha-cat is also involved in invasion and metastasis. In particular, reduction of alpha-cat expression is more correlated with invasive phenotype and lymph node metastasis than E-cad expression in human esophageal cancer.

Adult↗
PubMed1994

Urinary carnitine excretion in patients with heart failure.

To evaluate the fatty acid metabolism in heart failure, the semiquantitative analysis of urinary free carnitine and acylcarnitine was made by fast atom bombardment mass spectrometry (FABMS) in 22 patients (mean age 67.3 years) with heart failure and 19 age-matched healthy controls (average age 60.4 years). Urinary excretion of free carnitine was 0.20 +/- 0.118 ratio/mg creatinine in the healthy controls and 1.32 +/- 1.170 ratio/mg creatinine in the patients with heart failure. The latter value was significantly higher (p < 0.01). Patients with heart failure were classified into two groups according to the urinary free carnitine concentration. One was the high excretion group (2.19 +/- 0.102 ratio/mg creatinine, 12 cases) and the other was the low excretion group (0.37 +/- 0.212 ratio/mg creatinine, 10 cases). In the high excretion group, urinary acetylcarnitine was also increased, but no significant abnormalities were observed in the urinary organic acid profile. In the high group, 1 patient was classified as NYHA class III and 11 as NYHA class IV. Four patients died in the hospital. In the low excretion group, five patients were classified as NYHA class III and five as NYHA class IV. Only one patient died in the hospital. In the high group, patients with severe and prolonged heart failure tended to maintain higher values of urinary free carnitine. We could not find any abnormalities in fatty acid metabolism in patients with heart failure, but it is suspected that the patients who excrete large amounts of free carnitine into the urine, namely the patients with severe heart failure, have some possibility of carnitine deficiency.

Acetylcarnitine↗
PubMed1994

Autoantibodies against cardiac G-protein-coupled receptors define different populations with cardiomyopathies but not with hypertension.

It was previously shown that the second extracellular loop of cardiovascular G-protein-coupled receptors is an antigenic target for pharmacologically active autoantibodies in patients with idiopathic dilated cardiomyopathy. To extend these observations to cover patients with the same disease from different geographical origins or to patients with other cardiac diseases, peptides corresponding to the sequences of the second extracellular loops of the human M2 muscarinic receptors and beta adrenoceptors were used as antigens in an enzyme immunoassay. Sera from patients from Sweden and Japan with idiopathic dilated cardiomyopathy (DCM, n = 32), hypertrophic cardiomyopathy (HCM, n = 23), malignant essential hypertension (MEH, n = 11), malignant secondary hypertension (MSH, n = 10), and sera from healthy blood donors (HBD, n = 49) were tested. Sera from patients with DCM recognized the muscarinic receptor peptide in 38% of cases and the beta 1 adrenoceptor peptide in 31% of cases. In 50% of the positive patients, autoantibodies against both peptides coexisted as shown by competition experiments using both peptides as inhibitors. In HCM patients, there was a lower frequency of autoantibodies but with a higher but not significant predominance against the M2 peptide. No autoantibodies were detected in sera from patients with MEH or MSH. Autoantibodies against the M2 muscarinic receptors, affinity-purified from positive patients, displayed pharmacological activity as demonstrated by changes in the affinity and number of radioligand binding sites. In contrast, antibodies purified from positive HBD had no effect. These results confirm that autoantibodies displaying pharmacological activity against G-protein-coupled cardiovascular receptors are mainly restricted to patients with idiopathic dilated cardiomyopathy and that different autoantibody populations are responsible for the recognition of the different receptors.

Adult↗
PubMed1994

Functional roles of terminal glycomoieties in varicella-zoster virus infection.

Terminal glycomoieties of varicella-zoster virus glycoproteins were characterized by their reactivity with lectins and glycosidases, and the functional roles of terminal sugars were analyzed by cell-free virus infectivity. Terminal glycan structures of gpl possessed sialic acid linked alpha (2-3) to galactose of O-linked glycan and galactose-beta (1-4)-N-acetylglucosamine of N-linked glycan. Those of the putative gpIV possessed galactose-beta (1-4)-N-acetylglucosamine of N-linked glycan. Both glycoproteins had mannose alpha (1-3, 6, or 2) linked to mannose in their glycans. Their biological functions on cell-free virus infectivity were assessed by using lectins and exoglycosidases. Sialic acid of glycans on both the viral envelope and the cell surface had a negative effect on infectivity, and the latter had a larger effect on infectivity than the former. Maackia amurensis agglutinin, which recognizes sialic acid, enhanced infectivity more than expected from the simple neutralization of the negative effects of sialic acids between cells and virus. alpha-Mannosidase and alpha-glucosidase treatments of virus significantly reduced infectivity but those of cells did not. Therefore, alpha-mannose and alpha-glucose residues on the viral envelope had functional roles in cell-free virus infection. Inactivation of virus infectivity by concanavalin A was mainly due to the blocking of functional roles of terminal alpha-mannose and alpha-glucose residues of viral glycoproteins.

Acetylglucosamine↗
PubMed1994

Localization of [D-Ala2]deltorphin I-like immunoreactivity in perinatal rat respiratory system.

The localization of [D-Ala2]deltorphin I, a delta-opioid receptor ligand, was studied in the lower respiratory tract of developing rats using an immunohistochemical method. [D-Ala2]-like immunoreactive cells were detected first in the principal bronchus as early as embryonic day 16. As embryos grew, positive cells became gradually visible everywhere from principal bronchi to respiratory bronchioles. The density of positive cells reached the highest level on embryonic day 21, but decreased gradually after birth. Positive cells were no longer seen on postnatal day 30 in any region of the airways. No positive cells were ever found in the trachea or alveoli of rats at any age studied. Ultrastructural examination indicated that the immunoreactive cells possessed a similar morphology to serous or Clara cells of the respiratory epithelium. Immunoreaction products tended to locate at the apical cytoplasm of positive cells. The results suggests that [D-Ala2]-like molecule(s) may be expressed transiently in serous cells or Clara cells, or both, of the rat bronchopulmonary tract. Such a molecule may act as a pulmonary growth-promoting or a differentiation-initiating factor in an early period of lung development.

Animals↗