Biomedical subjects

A Matsuda

Publications and source records attributed to A Matsuda.

At least 19 recordsLinked to original sources

PubMed2007

A novel missense mutation (p.P52R) in amelogenin gene causing X-linked amelogenesis imperfecta.

Amelogenesis imperfecta (AI) is a hereditary disease with abnormal dental enamel formation. Here we report a Japanese family with X-linked AI transmitted over at least four generations. Mutation analysis revealed a novel mutation (p.P52R) in exon 5 of the amelogenin gene. The mutation was detected as heterozygous in affected females and as hemizygous in their affected father. The affected sisters exhibited vertical ridges on the enamel surfaces, whereas the affected father had thin, smooth, yellowish enamel with distinct widening of inter-dental spaces. To study the pathological cause underlying the disease in this family, we synthesized the mutant amelogenin p.P52R protein and evaluated it in vitro. Furthermore, we studied differences in the chemical composition between normal and affected teeth by x-ray diffraction analysis and x-ray fluorescence analysis. We believe that these results will greatly aid our understanding of the pathogenesis of X-linked AI.

Amelogenesis Imperfecta↗

PubMed2006

Association between ADAM33 polymorphisms and adult asthma in the Japanese population.

BACKGROUND: ADAM33, a member of the ADAM (a disintegrin and metalloprotease) family, is a putative asthma susceptibility gene recently identified by positional cloning. It is important to know whether the association exists in ethnically diverse populations. OBJECTIVE: To assess whether genetic functional variants of ADAM33 relate to the susceptibility or some phenotypes in adult patients with bronchial asthma in a Japanese population. METHODS: We searched for single nucleotide polymorphisms (SNPs) in ADAM33 by PCR-directed sequencing and identified 48 SNPs. Fourteen SNPs were selected with regard to the LD pattern, and genotyped by Taq-Man and PCR-RFLP methods. We conducted an association study of ADAM33 with 504 adult asthmatic patients and 651 controls, and haplotype analyses of related variants were performed. RESULTS: Significant associations with asthma were found for the SNPs T1 (Met764Thr), T2 (Pro774Ser), S2 and V-3 (with the lowest P-value for T1, P = 0.0015; OR 0.63). We analysed the haplotype using these four polymorphisms, and found a positive association with haplotype CCTG (P = 0.0024). CONCLUSION: Our results replicate associations reported recently in other ethnic populations, and suggest that the ADAM33 gene is involved in the development of asthma through genetic polymorphisms.

ADAM Proteins↗

PubMed2005

Synthesis of complex nucleoside antibiotics.

Herbicidin B and fully prtected tunicaminyluracil, which were undecose nucleoside antibiotics, were synthesized using a samarium diiodide (SmI2) mediated aldol reaction with the use of alpha-phenylthioketone as an enolate. The characteristics of the SmI2-mediated aldol reaction are that the enolate can be regioselectively generated and the aldol reaction proceeds under near neutral condition. This reaction is proved to be a powerful reaction for the synthesis of complex nucleoside antibiotics. The synthesis of caprazol, the core structure of caprazamycins, was conducted by the strategy including beta-selective ribosylation without using a neighboring group participation and the construction of a diazepanone by a modified reductive amination. Our synthetic route would provide a range of key analogues with partial structures to define the pharmacophore, which can be a lead for the development of more effective anti-bacterial agents.

Adenosine↗

PubMed2004

Suppressing effects of bisphenol A on the secretory function of ovine anterior pituitary cells.

We investigated the action of bisphenol A (BPA) on cellular GH release and content, cell number, GHmRNA expression, and concentrations of cellular cyclic AMP ([cAMP]c) and calcium ion ([Ca2+]c) in primary cultured ovine anterior pituitary cells. The following results were found: (1) BPA as well as nonylphenol (NP) at 10(-6) to 10(-3) M significantly and concentration-dependently suppressed basal and GHRH-stimulated GH release, and the cellular GH content, (2) BPA suppressed the cell number in a time- and concentration-dependent manner, (3) 10(-4)M BPA suppressed GHmRNA expression to 68% of control (BPA-free), and abolished GHRH (10(-8) M)-induced increases in [cAMP]c and [Ca2+]c. From these findings we conclude that BPA possesses a suppressing action on GH synthesis and release, and this suppressing action is probably related to impairment of cellular signal transduction systems in ovine anterior pituitary cells.

Animals↗

PubMed2004

Orthodontic treatment of a case of Becker muscular dystrophy.

Becker muscular dystrophy, similar to Duchenne muscular dystrophy, is a X-chromosomal linked anomaly characterized by progressive muscle wasting and weakness. Duchenne-type is known to have severe openbite with a steep mandibular plane, but there are no studies that describe the occlusal and skeletal patterns of the Becker-type. Here, we report the orthodontic treatment of a Becker muscular dystrophy patient. In the correction of his severe skeletal open bite general anesthesia or orthognathic surgery was not an option. Multiloop edgewise archwires were employed for orthodontic treatment. After 3 years and 8 months the open bite was corrected. During the retention period contact between the anterior teeth was maintained 8 months after active treatment despite a marked relapse tendency.

Adolescent↗

PubMed2004

Polymorphisms in ADAM33 are associated with allergic rhinitis due to Japanese cedar pollen.

BACKGROUND: A recent report provided evidence that a disintegrin and metalloprotease domain 33 (ADAM33), a member of the ADAM family, is a novel susceptibility gene in asthma linked to bronchial hyper-responsiveness. However, there has been no investigation of the genetic role of ADAM33 variants in nasal allergy. OBJECTIVE: The purpose of this study was to test the association between ADAM33 polymorphisms and Japanese cedar pollinosis (JCPsis), a most common seasonal allergic rhinitis in Japan. METHODS: We conducted a case-control association study among a Japanese population, involving 95 adult individuals with JCPsis and 95 normal healthy controls. A total of 22 single-nucleotide polymorphisms (SNPs) in ADAM33 were genotyped using PCR-based molecular methods. RESULTS: Six SNPs of ADAM33 gene, three in introns (7575G/A, 9073G/A and 12540C/T) and three in the coding region (10918G/C, 12433T/C and 12462C/T), were strongly associated with JCPsis (P = 0.0002-0.022 for absolute allele frequencies) and most of the SNPs were in linkage disequilibrium with each other. A higher frequency of the common alleles of these SNPs was noted for the subjects with JCPsis in comparison with healthy controls. We also identified a haplotype associated with the disease susceptibility. In addition, associations were found between ADAM33 polymorphisms and various cedar pollinosis phenotypes including clinical severity, eosinophil counts in nasal secretion and allergen-specific IgE levels in sera, but not total serum IgE levels. CONCLUSION: These results indicate that polymorphisms in the ADAM33 gene are associated with susceptibility to allergic rhinitis due to Japanese cedar pollen, but the functional relationship still needs clarification.

ADAM Proteins↗

PubMed2004

Minimization of sludge production and stable operational condition of a submerged membrane activated sludge process.

Modification of conventional activated sludge process by adding microfiltration type hollow fiber membrane module offers various advantages. The membrane module is immersed directly in the bioreactor to separate the treated water from the sludge and the modified process is called submerged membrane activated sludge process (SMASP). Bench scale SMASP units were operated at constant flux to study the possibility of minimizing the excess sludge production and stable operation at different SRT and BOD loading. The long SRT developed high stabilized MLSS concentration in the bioreactor and decreased the sludge loading rate [kg-BOD/kg-MLSS-d]. In SMASP, very low sludge yield coefficients (0.04-0.09 kg-MLSS/kg-BOD) were obtained at long SRT (500 d) and small BOD loading (< or =0.5 kg/(m3 x d)) as compared to conventional activated sludge process and these coefficients showed considerable minimization in excess activated sludge production. At the same operation conditions, suction pressure was also maintained low (<25 kPa), and then SMASP was operated stably for long time (approximately 200 d).

Biomass↗

PubMed2003

Observation of band renormalization effects in hole-doped high-Tc Superconductors.

We report a systematic high-resolution angle-resolved photoemission spectroscopy on high-T(c) superconductors Bi(2)Sr(2)Ca(n-1)Cu(n)O(2n+4) (n=1-3) to study the origin of many-body interactions responsible for superconductivity. For n=2 and 3, a sudden change in the energy dispersion, so called "kink", becomes pronounced on approaching (pi,0) in the superconducting state, while a kink appears only around the nodal direction in the normal state. For n=1, the kink shows no significant temperature dependence even across T(c). This could suggest that the coupling of electrons with Q=(pi,pi) magnetic mode is dominant in the superconducting state for multilayered cuprates, while the interactions at the normal state and that of single-layered cuprates have a different origin.

Journal Article↗

PubMed2003

BCS-like Bogoliubov quasiparticles in high-T(c) superconductors observed by angle-resolved photoemission spectroscopy.

We performed high-resolution angle-resolved photoemission spectroscopy on triple-layered high-T(c) cuprate Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta). We have observed the full energy dispersion (electron and hole branches) of Bogoliubov quasiparticles and determined the coherence factors above and below E(F) as a function of momentum from the spectral intensity as well as from the energy dispersion based on BCS theory. The good quantitative agreement between the experiment and the theoretical prediction suggests the basic validity of BCS formalism in describing the superconducting state of cuprates.

Journal Article↗

PubMed2003

Evaluation of static bone cavities with CT and MRI.

OBJECTIVES: To determine by CT and MRI the contents of static bone cavities (SBCs), which are thought to be formed by aberration of the submandibular gland. METHODS: Non-contrast-enhanced and contrast-enhanced CT was performed on 12 subjects (10 male and 2 female; age 18-64 years; mean age 57 years) in whom SBCs had been discovered incidentally on panoramic radiographs during routine dental treatment. MRI was also performed on 3 of the 12 subjects. RESULTS: No submandibular gland tissue was seen in the SBCs in any of the cases. However, fatty tissue of low attenuation was found in the SBCs in all cases on CT images. Blood vessels were seen in the SBCs in 10 cases, and enhanced soft tissue in contact with the bone cavity wall was seen in the SBCs in 2 cases. Blood vessels in the SBCs were observed on MR images in all three cases. Dilatation of the cavity blood vessels was seen in all 10 cases. Slight tortuosity of the blood vessels was seen in 4 of the 10 cases. CONCLUSIONS: Examination of contrast-enhanced CT images and MR images revealed that the contents of SBCs were not aberrations of the submandibular gland, as has generally been thought, but fatty tissue, blood vessels and soft tissue.

Adipose Tissue↗

PubMed2002

Low energy excitation and scaling in Bi(2)Sr(2)Ca(n-1)Cu(n)O(2n+4) (n=1-3): angle-resolved photoemission spectroscopy.

Angle-resolved photoemission spectroscopy (ARPES) has been performed on the single- to triple-layered Bi-family high-T (c) superconductors (Bi(2)Sr(2)Ca(n-1)Cu(n)O(2n+4), n=1-3). We found a sharp coherent peak as well as a pseudogap at the Fermi level in the triple-layered compound. Comparison among three compounds has revealed a universal rule that the characteristic energies of superconducting and pseudogap behaviors are scaled with the maximum T (c).

Journal Article↗

PubMed2002

Serum thymidine kinase and soluble interleukin-2 receptor predict recurrence of malignant lymphoma.

Before and after therapy, serum thymidine kinase (TK) and soluble interleukin-2 receptor (sIL-2R) were serially determined in 28 patients with malignant lymphoma (ML). In 15 patients achieving and maintaining complete remission (CR) for more than 2 years, serum TK and sIL-2R were unchanged or decreased gradually. In contrast, logarithmic linear increases of TK and sIL-2R were observed in 13 relapsed patients. The increments of the serum markers occurred more than 10 months before the relapse. A significant positive correlation between the slope of the line for TK and that for sIL-2R was noted. The doubling time for TK estimated from the slope also showed a positive correlation with that for sIL-2R. Taken together, serum TK and sIL-2R were shown to be quite sensitive and interrelated serum markers for the recurrence of ML. Slopes of logarithmic linear increase, which are proper and specific for the individual patients, are inversely correlated with the doubling time and reflect proliferation of ML. We conclude that serum TK and sIL-2R are better predictors of relapse than LDH and the international prognostic index (IPI).

Adult↗

PubMed2001

Highly alpha- and beta-selective radical C-glycosylation reactions using a controlling anomeric effect based on the conformational restriction strategy. A study on the conformation-anomeric effect-stereoselectivity relationship in anomeric radical reactions.

We hypothesized that, because the stereoselectivity of anomeric radical reactions was significantly influenced by the anomeric effect, which can be controlled by restricting the conformation of the radical intermediate, the proper conformational restriction of the pyranose ring of the substrates would therefore make highly alpha- and beta-stereoselective anomeric radical reactions possible. Thus, the conformationally restricted 1-phenylseleno-D-xylose derivatives 9 and 10, restricted in a (4)C(1)-conformation, and 11 and 12, restricted in a (1)C(4)-conformation, were designed and synthesized by introducing the proper protecting groups on the hydroxyl groups on the pyranose ring as model substrates for the anomeric radical reactions. The radical deuterations with Bu(3)SnD and the C-glycosylation with Bu(3)SnCH(2)CH [double bond] CH(2) or CH(2) [double bond] CHCN, using the (4)C(1)-restricted substrates 9 and 10, afforded the corresponding alpha-products (alpha/beta = 97:3-85:15) highly stereoselectively, whereas the (1)C(4)-restricted substrates 11 and 12 selectively gave the beta-products (alpha/beta = 1:99-0:100). Thus, stereoselectivity was significantly increased by conformational restriction and was completely inverted by changing the substrate conformation from the (4)C(1)-form into the (1)C(4)-form. Ab initio calculations suggested that the radical intermediates produced from these substrates possessed the typical (4)C(1)- or (1)C(4)-conformation, which was similar to that of the substrates, and that the anomeric effect in these conformations would be the factor controlling the transition state of the reaction. Therefore, the highly alpha- and beta-selective reactions would occur because of the anomeric effect, which could be manipulated by conformational restriction of the substrates, as expected. This would be the first radical C-glycosylation reaction to provide both alpha- and beta-C-glycosides highly stereoselectively.

Free Radicals↗

PubMed2001

Fusion of ETV6 to fibroblast growth factor receptor 3 in peripheral T-cell lymphoma with a t(4;12)(p16;p13) chromosomal translocation.

Fusions of the ETV6/TEL gene to receptor or protein tyrosine kinases (TKs), such as PDGFRbeta, JAK2, ABL, ABL2, TRKC, and Syk, have been reported in various hematological malignancies. Expression of the resultant chimeric proteins is believed to lead to constitutive TK activity through activation by the helix-loop-helix (HLH) domain of ETV6. We identified a novel ETV6 partner gene, fibroblast growth factor receptor 3 (FGFR3), in a patient with peripheral T-cell lymphoma (PTCL) with a t(4;12)(p16;p13) translocation. The ETV6-FGFR3 transcript showed a fusion of exon 5 of ETV6 to exon 10 of FGFR3, resulting in an open reading frame for a chimeric protein consisting of the HLH domain of ETV6 and the TK domains of FGFR3. This is the first report of ETV6 and FGFR3 involvement in PTCL.

Amino Acid Sequence↗

PubMed2001

Establishment of CHO cell lines expressing four N-methyl-D-aspartate receptor subtypes and characterization of a novel antagonist PPDC.

To develop an assay system that allows the N-methyl-D-aspartate (NMDA) receptor subtype-selective antagonistic potency of drugs, we have established Chinese hamster ovary cell lines expressing the four NMDA receptor subtypes (GluRepsilon1/zeta1-GluRepsilon4/zeta1) heat-indelibly. Using these clonal cells, we found that a novel antagonist, (1S,2R)-1-phenyl-2[(S)-1-aminopropyl]-N,N-diethylcyclopropanecarboxamide, was less selective for the GluRepsilon1/zeta1: the IC(50) values for the GluRepsilon1/zeta1-GluRepsilon4/zeta1 were 41.7, 13.3, 12.6 and 11.5 microM, respectively, while two well-known antagonists, DL-2-amino-5-phosphonovaleric acid and ifenprodil, showed the known potency and selectivity for each subtype. Thus, the established clonal cells are of use in characterizing the pharmacological properties of drugs that act on NMDA receptors.

Animals↗

PubMed2001

Crystallographic studies on damaged DNAs IV. N( 4)-methoxycytosine shows a second face for Watson-Crick base-pairing, leading to purine transition mutagenesis.

To investigate the mutation mechanism of purine transitions in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCAAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and the crystal structure determined by X-ray analysis. The duplex structure is similar to that of the original undamaged B-form dodecamer, indicating that the methoxylation does not affect the overall DNA conformation. Electron density maps clearly show that the two mo(4)C residues form Watson-Crick-type base pairs with the adenine residues of the opposite strand and that the methoxy groups of mo(4)C adopt the anti conformation to N(3) around the C(4)-N(4) bond. For the pair formation through hydrogen bonds the mo(4)C residues are in the imino tautomeric state. Together with previous work, the present work establishes that the methoxylated cytosine residue can present two alternate faces for Watson-Crick base-pairing, thanks to the amino<-->imino tautomerism allowed by methoxylation. Based on this property, two gene transition routes are proposed.

Adenine↗

PubMed2001

Liposome-encapsulated superoxide dismutase suppresses liposome-mediated augmentation of TNF-alpha production from peripheral blood leucocytes.

Liposome-encapsulated hemoglobin (LEH), a candidate for a red cell substitute, has been reported to be cleared from circulation primarily by the phagocytic system and modulate the production of inflammatory cytokines, such as TNF-alpha and IL-6, both in vivo and in vitro. In this study, we investigated the effects of liposome vesicles on the LPS-induced TNF-alpha production using a whole blood culture system. We also studied the effects of superoxide dismutase (SOD) encapsulated in liposome on the cytokine production. The pre-treatment of whole blood with liposome vesicles potentiated the LPS-induced TNF-alpha production. The encapsulation of SOD in the liposome vesicles suppressed the liposome-mediated augmentation of TNF-alpha production in a dose-dependent manner. These results suggest that encapsulation of SOD in LEH decreases the production of inflammatory cytokines from the phagocytic system which may be caused or augmented by LEH infusion in vivo.

Drug Carriers↗

PubMed2001

Total synthesis of cyclic ADP-carbocyclic-ribose, a stable mimic of Ca2+-mobilizing second messenger cyclic ADP-ribose.

The synthesis of cyclic ADP-carbocyclic-ribose (cADPcR, 4) designed as a stable mimic of cyclic ADP-ribose (cADPR, 1), a Ca2+-mobilizing second messenger, was achieved using as the key step a condensation reaction with the phenylthiophosphate-type substrate 14 to form an intramolecular pyrophosphate linkage. The N-1-carbocyclic-ribosyladenosine derivative 16 was prepared via the condensation between the imidazole nucleoside derivative 17, prepared from AICA-riboside (19), and the readily available optically active carbocyclic amine 18. Compound 16 was then converted to the corresponding 5' '-phosphoryl-5'-phenylthiophosphate derivatives 14. Treatment of 14 with AgNO3 in the presence of molecular sieves (3 A) in pyridine at room temperature gave the desired cyclization product 32 in 93% yield, and subsequent acidic treatment provided the target cADPcR (4). This represents a general method for synthesizing biologically important cyclic nucleotides of this type. 1H NMR analysis of cADPcR suggested that its conformation in aqueous medium is similar to that of cADPR. cADPcR, unlike cADPR, was stable under neutral and acidic conditions, where under basic conditions, it formed the Dimroth-rearranged N6-cyclized product 34. cADPcR was also stable in rat brain membrane homogenate which has cADPR degradation activity. Furthermore, cADPcR was resistant to the hydrolysis by CD38 cADPR hydrolase, while cADPR was rapidly hydrolyzed under the same conditions. When cADPcR was injected into sea urchin eggs, it caused a significant release of Ca2+ in the cells, an effect considerably stronger than that of cADPR. Thus, cADPcR was identified as a stable mimic of cADPR.

ADP-ribosyl Cyclase↗