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Masahiro Yoshida

Publications and source records attributed to Masahiro Yoshida.

At least 55 records · Page 3Linked to original sources
PubMed2004

Thermophilic, reversible gamma-resorcylate decarboxylase from Rhizobium sp. strain MTP-10005: purification, molecular characterization, and expression.

We found the occurrence of thermophilic reversible gamma-resorcylate decarboxylase (gamma-RDC) in the cell extract of a bacterium isolated from natural water, Rhizobium sp. strain MTP-10005, and purified the enzyme to homogeneity. The molecular mass of the enzyme was determined to be about 151 kDa by gel filtration, and that of the subunit was 37.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; in other words, the enzyme was a homotetramer. The enzyme was induced specifically by the addition of gamma-resorcylate to the medium. The enzyme required no coenzyme and did not act on 2,4-dihydroxybenzoate, 2,5-dihydroxybenzoate, 3,4-dihydroxybenzoate, 3,5-dihydroxybenzoate, 2-hydroxybenzoate, or 3-hydroxybenzoate. It was relatively thermostable to heat treatment, and its half-life at 50 degrees C was estimated to be 122 min; furthermore, it catalyzed the reverse carboxylation of resorcinol. The values of k(cat)/K(m) (mMu(-1) . s(-1)) for gamma-resorcylate and resorcinol at 30 degrees C and pH 7 were 13.4 and 0.098, respectively. The enzyme contains 327 amino acid residues, and sequence identities were found with those of hypothetical protein AGR C 4595p from Agrobacterium tumefaciens strain C58 (96% identity), 5-carboxyvanillate decarboxylase from Sphingomonas paucimobilis (32%), and 2-amino-3-carboxymuconate-6-semialdehyde decarboxylases from Bacillus cereus ATCC 10987 (26%), Rattus norvegicus (26%), and Homo sapiens (25%). The genes (graA [1,230 bp], graB [888 bp], and graC [1,056 bp]) that are homologous to those in the resorcinol pathway also exist upstream and downstream of the gamma-RDC gene. Judging from these results, the resorcinol pathway also exists in Rhizobium sp. strain MTP-10005, and gamma-RDC probably catalyzes a reaction just before the hydroxylase in it does.

Amino Acid Sequence↗
PubMed2004

[Development of novel type of transition metal-catalyzed cascade reactions utilizing small ring systems and the applications].

This review summarizes the novel type of palladium-catalyzed cascade ring expansion reactions of cyclobutanols with various unsaturated bonds. The intramolecular cascade ring expansion-cyclizations of isopropenylcyclobutanol proceeds smoothly in the presence of the palladium (II) complex. The diastereoselectivity of the obtained naphthohydrindans can be controlled by the choice of the reaction solvents. As an application utilizing this reaction, total synthesis of (+)-equilenin has been achieved. The reaction of allenylcyclobutanols with a iodoalkenyl side chain with a palladium (0) catalyst produces the cyclized products that have seven- and eight-membered rings. The reaction can be successfully applied to the stereospecific synthesis of alpha-substituted cyclopentanones with a quaternary carbon stereocenter. The cyclobutanols containing a propargylic component react with phenols in the presence of the palladium (0) catalyst to afford the phenoxy-substituted cyclopentanones via a nucleophilic addition-ring expansion process. The reaction also proceeds stereospecifically to afford the corresponding products with high efficiency.

Alkadienes↗
PubMed2004

Analysis on the dispersal pattern of newly introduced Latrodectus hasseltii (Araneae: Theridiadae) in Japan by spider diagram.

The dispersal pattern of the widow spider Latrodectus hasseltii (Araneae: Theridiadae), in Osaka Prefecture, Japan, was analyzed from accumulated survey data of spider distribution. All confirmed infested points from 1996 to 2002 were plotted on a map, and infested points in each survey year were connected with the nearest previously confirmed points. Expansion patterns of the confirmed habitats were analyzed by year and dispersion distances were classified by using spider diagram, one of method of geographical information system spatial analysis. L. hasseltii moves by walking step by step on the ground, mainly in coastal areas during early stages of infestation, and also can be conveyed over distances by various vehicles, mainly in inland areas. These analyses show L. hasseltii does not move by ballooning.

Animals↗
PubMed2004

Lanthanoid element recognition on surface-imprinted polymers containing dioleylphosphoric acid as a functional host.

Surface-imprinted polymers have been newly developed for the separation of lanthanoid elements: i.e. La(III), Ce(III), and Dy(III). The imprinted polymers were prepared by surface template polymerization with dioleylphosphoric acid, which exhibits a high affinity to lanthanoids, as a functional host molecule. Separation behavior of La(III), Ce(III) and Dy(III) was investigated with the imprinted polymers, and the imprinting effect of the polymers was evaluated in comparison with that of the unimprinted polymers and also with a conventional solvent extraction method for the same lanthanoid ions. The results indicate that the increase of selectivity for Dy(III) compared to the rest of the ions by the surface-imprinted polymers originated from a synergistic effect of both the affinity with the functional host molecule in nature and the size exclusion by the cavity formed on the polymer surface.

Journal Article↗
PubMed2003

Palladium-catalyzed enantiospecific reaction of propargylic carbonates with phenols: cascade chirality transfer.

[reaction: see text] A cascade chirality transfer process has been achieved by the palladium-catalyzed reaction of substituted propargylic carbonates with phenols. The reaction proceeds in a highly enantiospecific manner to produce chiral cyclic carbonates, which supports the existence of the pi-propargylpalladium intermediate in the reaction mechanism. The (E)- and (Z)-selectivity of the products can be controlled by choice of the phosphine ligand.

Journal Article↗
PubMed2003

A novel methodology for the synthesis of cyclic carbonates based on the palladium-catalyzed cascade reaction of 4-methoxycarbonyloxy-2-butyn-1-ols with phenols, involving a novel carbon dioxide elimination-fixation process.

A palladium-catalyzed CO(2)-recycling reaction has been developed. Reaction of 4-methoxycarbonyloxy-2-butyn-1-ols with phenols, carried out in the presence of a palladium catalyst, produces phenoxy-substituted cyclic carbonates by way of a pathway involving a CO(2) elimination-fixation. A variety of propargylic alcohols and phenols participate in these reactions which yield cyclic carbonates with high efficiencies. Stereoselective construction of trans-cyclic carbonates is achieved by using nonsymmetric substrates. Highly enantioselective reactions occur when (S)-BINAP is used as a ligand. Reaction of 4-phenoxycarbonyloxy-2-butyn-1-ol in the presence of the palladium catalyst yields the corresponding cyclic carbonates via a three-component decomposition-reconstruction process.

Journal Article↗
PubMed2003

Design, synthesis, and evaluation of beta-galactosylceramide mimics promoting beta-glucocerebrosidase activity in keratinocytes.

We have established an efficient synthesis of mimics of beta-galactosylceramide (beta-GalCer) increasing a beta-glucocerebrosidase (beta-GlcCer'ase) activity that associates with the skin barrier function. Among the synthetic beta-GalCer analogues (6a-6e) described herein, compound 6e exhibited a potent effect on the activation of beta-GlcCer'ase function in vitro and reduced the transepidermal water loss (TEWL) level in a UVB-induced barrier disrupted mice model. These findings indicated that compound 6e could be useful for cosmetics and medicines to improve skin barrier function.

Animals↗
PubMed2003

Immunomic analysis of human sarcoma.

The screening of cDNA expression libraries from human tumors with serum antibody (SEREX) has proven to be a powerful method for identifying the repertoire of tumor antigens recognized by the immune system of cancer patients, referred to as the cancer immunome. In this regard, cancer/testis (CT) antigens are of particular interest because of their immunogenicity and restricted expression patterns. Synoivial sarcomas are striking with regard to CT antigen expression, with >80% of specimens homogeneously expressing NY-ESO-1 and MAGE-A3. In the present study, 54 sarcoma patients were tested for serum antibodies to NY-ESO-1, SSX2, MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, CT7, and CT10. Two patients had detectable antibodies to CT antigens, and this seroreactivity was restricted to NY-ESO-1. Thus, although highly expressed in sarcoma, CT antigens do not induce frequent humoral immune responses in sarcoma patients. Sera from these two patients were used to immunoscreen cDNA libraries from two synovial sarcoma cell lines and normal testis, resulting in the identification of 113 distinct antigens. Thirty-nine antigens were previously identified by SEREX analysis of other tumor types, and 2339 antigens (59%) had a serological profile that was not restricted to cancer patients, indicating that only a proportion of SEREX-defined antigens are cancer-related. A novel CT antigen, NY-SAR-35, mapping to chromosome Xq28 was identified among the cancer-related antigens, and encodes a putative extracellular protein. In addition to testis-restricted expression, NY-SAR-35 mRNA was expressed in sarcoma, melanoma, esophageal cancer, lung cancer and breast cancer. NY-SAR-35 is therefore a potential target for cancer vaccines and monoclonal antibody-based immunotherapies.

Antigens, Neoplasm↗
PubMed2003

Amphiregulin is a potent mitogen for the vascular smooth muscle cell line, A7r5.

The regulation of amphiregulin, an epidermal growth factor (EGF) family member, and its effect on vascular smooth muscle cells (VSMC) were examined. Amphiregulin mRNA was upregulated by amphiregulin itself as well as alpha-thrombin. Amphiregulin caused an approximate 3-fold increase in DNA synthesis. Its effect on growth was compared with those of other mitogens, and was found to be approximately 3.5-, 2.4-, and 1.0-fold greater than those of endothelin-I (ET-I), alpha-thrombin, and platelet-derived growth factor-AB (PDGF-AB), respectively. As evidenced by Western blot analysis, amphiregulin stimulated the phosphorylation of p42/p44-mitogen-activated protein kinase (MAPK), p38-MAPK, c-Jun NH2-terminal protein kinase (JNK), and Akt/protein kinase B (PKB), respectively. By statistical analysis, the amphiregulin-induced growth effect was significantly decreased by the MAP kinase/ extracellular regulated kinase kinase-1 (MEK-1) inhibitor PD98059, p38-MAPK inhibitor SB203580, and phosphatidylinositol 3-kinase (PI-3 kinase) inhibitor wortmannin, respectively, but was not decreased by JNK inhibitor SP600125. These results suggest that amphiregulin is the most potent mitogen of the mitogens tested, and its growth effect is mediated at least in part through the p42/p44-MAPK, p38-MAPK, and PI-3 kinase-Akt/PKB pathways in VSMC.

Amphiregulin↗
PubMed2003

Rhodium-catalyzed addition of arylboronic acids to alkynyl aza-heteroaromatic compounds in water.

Alkynyl heteroaromatic compounds reacted with arylboronic acids to give addition products in the presence of a rhodium catalyst. The best results were obtained when a novel pyridine-substituted water-soluble phosphine ligand was used. The reactions proceed to give trisubstituted alkenes from various arylboronic acids and alkynyl heteroaromatic compounds with high regioselectivity. Only alkynes with a nitrogen atom in proximity to the triple bond were converted to the corresponding alkenes, as expected for a chelation-controlled addition.

Journal Article↗
PubMed2003

Vascular endothelial growth factor in children with congenital heart disease.

BACKGROUND: Children with cyanotic congenital heart disease may experience the development of abnormal vessels that become a source of significant morbidity. Abnormal vessel proliferation in these children may take several forms, including systemic-to-pulmonary collateral arteries, systemic-to-pulmonary venous collaterals, systemic venous collateral channels after bidirectional cavopulmonary anastomosis, and pulmonary arteriovenous malformations. However, no entity responsible for these abnormalities has been identified yet. This study determined whether children with cyanotic congenital heart disease have elevated serum levels of vascular endothelial growth factor (VEGF) and whether elevated VEGF correlated with these abnormal vessels. METHODS: Mean systemic room air oxygen saturation (SpO2), blood cell counts (RBC), and serum VEGF levels were measured preoperatively. Samples were obtained from 61 children with acyanotic heart disease (group N) and 102 children with cyanotic heart disease (group C) before cardiac surgery. Postoperative catheterization was performed 1-month after the operation to evaluate the abnormal vessels in group C. RESULTS: The VEGF level was significantly elevated in group C (355.0 +/- 287.1 pg/mL) compared with group N (203.0 +/- 221.6 pg/mL; p < 0.001). VEGF levels in patients with a single ventricle associated with asplenia syndrome (n = 7) in group C were significantly elevated (711.9 +/- 443.5 pg/mL) compared with other patients. There was no significant correlation between VEGF level and SpO2 or RBC. Abnormal vessels were diagnosed in 19.6% (20/102) patients in group C. There was no difference in VEGF levels between the patients with abnormal vessels (336.8 +/- 182.5 pg/mL) and the patients without abnormal vessels (359.1 +/- 306.8 pg/mL). CONCLUSIONS: Children with cyanotic heart disease have elevated systemic levels of VEGF, especially in those patients with a single ventricle associated with asplenia syndrome. There was no significant relationship in VEGF levels between the patients with abnormal vessels and without these vessels.

Adolescent↗
PubMed2003

Secretion of A-type and B-type natriuretic peptides into the bloodstream and pericardial space in children with congenital heart disease.

OBJECTIVE: To determine the secretion of A-type and B-type natriuretic peptides into the bloodstream and pericardial space in children with congenital heart disease. METHODS: Plasma and pericardial fluid samples were obtained from 77 patients undergoing total correction for congenital heart disease. All patients underwent detailed right-sided and left-sided cardiac catheterization preoperatively. RESULTS: A-type natriuretic peptide levels in pericardial fluid were lower than those in plasma (33.0 +/- 23.1 versus 39.8 +/- 33.6 pg/mL, P <.05), and B-type natriuretic peptide levels in pericardial fluid showed marked elevations compared with those in plasma (231.9 +/- 305.6 versus 19.8 +/- 29.3 pg/mL, P <.0001). The A-type and B-type natriuretic peptide levels in plasma correlated with those in pericardial fluid (R =.522, P <.0001; R =.595, P <.0001). For A-type and B-type natriuretic peptide levels in plasma, the relation with biventricular volume had the highest correlation (R =.669, P <.0001; R =.652, P <.0001). The patients with a pulmonary-to-systemic flow ratio greater than 2 (n = 19) had high levels of natriuretic peptides not only in plasma (58.3 +/- 43.2, 40.5 +/- 49.4 pg/mL, P <.05) but also in pericardial fluid (44.4 +/- 31.5, 287.2 +/- 198.5 pg/mL, P <.05), and higher correlation between A-type and B-type natriuretic peptide plasma levels and left ventricular volume (R =.913, P <.0001; R =.787, P <.0001). CONCLUSIONS: B-type natriuretic peptide is secreted not only into the bloodstream but also into the pericardial space in children with congenital heart disease. Natriuretic peptide levels in plasma correlated well with biventricular volume. The left ventricle was considered to be the main source of secreted natriuretic peptides in the patients with a pulmonary-to-systemic flow ratio greater than 2.

Adolescent↗
PubMed2003

Pulmonary atresia with intact ventricular septum: strategy based on right ventricular morphology.

OBJECTIVES: Management strategy for pulmonary atresia with intact ventricular septum is controversial. We treated patients with this anomaly according to a management protocol based on our quantitative assessment of right ventricular morphology (index of right ventricular development and right ventricle-tricuspid valve index). In the present study, we reviewed a 20-year experience of the surgical treatment at our institution to define guidelines for selecting the appropriate type of surgical procedure. METHODS: Between April 1981 and June 2002, 45 consecutive patients with pulmonary atresia with intact ventricular septum underwent surgical treatment. Open transpulmonary valvotomy was performed in 27 patients and Blalock-Taussig shunt in 18 patients as the initial palliative procedure. Three patients who underwent a successful transpulmonary valvotomy alone in the neonatal period required no further operation. Definitive repair was performed in 32 patients. Biventricular repair was performed on 19 patients, one and a half ventricular repair in 3, and Fontan-type operation in 10. RESULTS: There were 1 early and 2 late deaths before the definitive operation in patients who underwent transpulmonary valvotomy. Two patients who had coronary artery interruption died 3 months and 13 years after the initial Blalock-Taussig shunt. There were 1 early and 2 late deaths after the definitive operation. Actuarial survival, including noncardiac death, was 91.1% at 5 years after the initial procedure and 81.5% at 10 years. CONCLUSIONS: We treated patients with pulmonary atresia with intact ventricular septum according to a management protocol based on our quantitative assessment of right ventricular morphology with good results.

Cardiac Catheterization↗
PubMed2003

Enhanced DNA synthesis accompanied by constitutive phosphorylation of the ERK pathway in human fibroblasts cultured on a polyelectrolyte complex.

In this study, we examined the cellular and molecular responses of fibroblasts cultured on a polyelectrolyte complex (PEC) derived from sulfated chitin as a polyanion and chitosan as a polycation. On PEC-coated dishes, the fibroblasts aggregated and then developed spheroid-like structures. At earlier stages of culture, DNA synthesis of cells cultured on PEC was stimulated approximately 75% higher than control cells. Among various signaling molecules examined, including mitogen-activated protein kinases, Akt/PKB and p53, an extracellular-signal-regulated kinase (ERK) was selectively and constitutively phosphorylated in cells cultured on PEC. The constitutive phosphorylation of ERK was derived from an activation of the ERK kinase MEK, but not from an inactivation of the ERK phosphatase MKP-1. Furthermore, ERK phosphorylation was almost abolished by a membrane receptor tyrosine kinase inhibitor. The enhanced phosphorylation of focal adhesion kinase, a downstream molecule of integrins, was also observed in cells cultured on PEC. These results suggest that fibroblasts recognize PEC as a continuous mitogenic stimulant which results in the constitutive activation of the MEK-ERK pathway toward mitogenesis. Further, PEC interacts with the cell membrane leading to activation of membrane molecules, including integrins and receptor tyrosine kinases. These responses may account, at least in part, for the potential use of PEC as a biomaterial for tissue regeneration.

Cell Aggregation↗
PubMed2003

Expression of cancer/testis (CT) antigens in lung cancer.

Cancer/testis (CT) antigens are considered promising candidates for vaccine-based immunotherapy. The aim of this study was to investigate which CT antigens should be targeted in immunotherapy of Japanese lung cancer. To determine the expression of 12 CT antigens in Japanese primary lung cancers and cell lines, a reverse-transcription polymerase chain reaction (RT-PCR) analysis was performed. Among 46 primary lung cancers, high expression rates were found for MAGE-3 (41%, 19/46), and SSX-4 (35%, 16/46). A similar pattern of CT antigen expression was observed in 29 lung cancer cell lines. The expression frequency of a certain CT antigen, namely NY-ESO-1, in Japanese cases was drastically different from that in Caucasians. Polyvalent CT antigen vaccine may be effective to increase the number of lung cancer patients eligible for cancer-specific immunotherapy. Vaccination with MAGE-3 and SSX-1 would cover 57% of all patients, with three antigens, MAGE-3, SSX-1, and MAGE-4, would cover 65%, and with four antigens, MAGE-3, SSX-1, MAGE-4 and SSX-4, would cover 70%. Simultaneous expression of two or more CT antigens was observed in 25/46 (54%) primary lung cancers and 18/29 (62%) lung cancer cell lines. Polyvalent CT antigen vaccines may be also effective to reduce a chance of emergence of antigen loss variants, thus preventing tumors from escaping from the immune system. For this purpose, vaccination with combinations of MAGE-3 with MAGE-6, SSX-4, MAGE-1 or BAGE may be effective for a quarter of Japanese lung cancer patients. In addition, in silico surveys of dbEST database were used for identification of new CT antigens. We identified a novel gene, TES101RP, expressed only in some small cell lung cancers (SCLC) and in testis, as confirmed by RT-PCR analysis.

Antigens, Neoplasm↗
PubMed2003

Surgical management of trabecular ventricular septal defects: the sandwich technique.

BACKGROUND: Surgical closure of trabecular ventricular septal defects is difficult and often unsuccessful. OBJECTIVE: We performed closure of trabecular ventricular septal defects by sandwiching the septum between 2 polyester felt patches placed in the left ventricle and right ventricle without ventriculotomy. METHODS: Eleven patients (7 boys and 4 girls) underwent a sandwiching closure at a mean age of 4.7 years (range, 0.4-9.7 years) and a mean weight of 16.7 kg (range, 4.6-52 kg). Associated cardiac malformations were present in 9 of the 11 patients. Seven patients had undergone previous operations. The trabecular ventricular septal defects are exposed through the tricuspid valve and also from the left ventricular side through a coexisting large perimembranous ventricular septal defect or through the mitral valve through an interatrial septostomy. Two forceps, one each from the right and left ventricular side, lead a 3F Nelaton catheter through the trabecular defect. An oversized circular polyester felt patch mounted on a 3-0 Nespolen suture attached to the Nelaton catheter is then passed into the left ventricle. The suture ends are then passed through a slightly smaller polyester felt patch on the right ventricular side of the septum. The Nespolen suture is then tied, thereby sandwiching the septum between the 2 patches. RESULTS: Time required for the procedure was less than 20 minutes in each case. There were no hospital deaths, and the postoperative course was uneventful in all patients. There was no residual shunt in 3 patients, and a minimal residual shunt was observed in 5 patients. Mild residual shunt was observed in 3 patients. Cardiac catheterization was performed 1 month postoperatively in 8 patients in whom residual shunt was noted on echocardiography. Five of 8 patients had a minimal residual shunt (pulmonary blood flow/systemic blood flow ratio = 1.0). Three patients had a residual shunt (pulmonary blood flow/systemic blood flow ratio = 2.0, 1.6, and 1.2). The patient with a pulmonary blood flow/systemic blood flow ratio of 2.0 had a "Swiss cheese" ventricular septal defect, and a residual shunt remained around the patch. However, the residual shunt decreased to a pulmonary blood flow/systemic blood flow ratio of 1.6 at examination 16 months postoperatively. Echocardiography showed that the residual shunt had also decreased in another 2 patients. CONCLUSIONS: We conclude that the sandwich technique is safe and easy. Even in cases with a residual shunt present, the shunt is expected to decrease as time passes. Further experience and longer follow-up of these patients are necessary to conclude whether this technique is applicable to neonates and young infants.

Blood Flow Velocity↗
PubMed2002

Thermostable aldehyde dehydrogenase from psychrophile, Cytophaga sp. KUC-1: enzymological characteristics and functional properties.

We found the occurrence of NAD(P)(+)-dependent aldehyde dehydrogenase (EC1.2.1.5) in the cells of a psychrophile from Antarctic seawater, Cytophaga sp. KUC-1, and purified to homogeneity. About 50% of the enzyme activity remained even after heating at 50 degrees C for 65min and the highest activity was observed in the range of 55-60 degrees C. The enzyme was thermostable and thermophilic, although it was derived from a psychrophile. The circular dichroism at 222nm of the enzyme showed a peak at 32 degrees C. This temperature was closely similar to the transition temperature in the Arrhenius plots. The stereospecificity for the hydride transfer at C4-site of nicotinamide moiety of NADH was pro-R. The gene encoding the enzyme consisted of an open reading frame of 1506-bp encoding a protein of 501 amino acid residues. The significant sequence identity (61%) was found between the Cytophaga and the Pseudomonas aeruginosa enzymes, although their thermostabilities are completely different.

Aldehyde Oxidoreductases↗