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Biomedical subjects

Nobuhiro Suzuki

Publications and source records attributed to Nobuhiro Suzuki.

At least 37 records · Page 2Linked to original sources
PubMed2005

Complicated water orientations in the minor groove of the B-DNA decamer d(CCATTAATGG)2 observed by neutron diffraction measurements.

It has long been suspected that the structure and function of a DNA duplex can be strongly dependent on its degree of hydration. By neutron diffraction experiments, we have succeeded in determining most of the hydrogen (H) and deuterium (D) atomic positions in the decameric d(CCATTAATGG)2 duplex. Moreover, the D positions in 27 D2O molecules have been determined. In particular, the complex water network in the minor groove has been observed in detail. By a combined structural analysis using 2.0 A resolution X-ray and 3.0 A resolution neutron data, it is clear that the spine of hydration is built up, not only by a simple hexagonal hydration pattern (as reported in earlier X-ray studies), but also by many other water bridges hydrogen-bonded to the DNA strands. The complexity of the hydration pattern in the minor groove is derived from an extraordinary variety of orientations displayed by the water molecules.

Base Sequence↗
PubMed2005

Gastric antral vascular ectasia in 2-yr-old girl undergoing unrelated cord blood stem cell transplantation.

Gastrointestinal bleeding is a common complication after hematopoietic stem cell transplantation (HSCT) and is often related to acute graft-vs.-host disease (aGVHD). Gastric antral vascular ectasia (GAVE), recently recognized as a complication after HSCT, is a rare cause of severe gastrointestinal bleeding, which has only been reported in adult patients so far. We report a 2-yr-old girl who developed GAVE after unrelated cord blood stem cell transplantation (CBSCT) as treatment of intractable Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH). Her conditioning regimen for CBSCT consisted of etoposide, busulfan, and cyclophosphamide. She was doing well after CBSCT without recurrence and developed only grade I aGVHD. She suddenly developed coffee ground emesis, tarry stools and severe anemia 76 days after CBSCT. As antacids were ineffective, esophagogastroduodenoscopy was performed and revealed GAVE on day 97. Endoscopic coagulation therapy was performed twice; subsequently, she needed no further transfusions and there was no clinical recurrence of GAVE.

Adolescent↗
PubMed2005

Passive immunization of the Abeta42(43) C-terminal-specific antibody BC05 in a mouse model of Alzheimer's disease.

BACKGROUND: Over the past few years, amyloid beta protein (Abeta) vaccination has become one of the most effective treatments for Alzheimer's disease. However, the appearance of severe side effects during clinical trials has highlighted the need for improved safety and efficacy. Although antibodies directed against the amino (N)-termini of Abeta are highly effective for passive immunization, a substantial risk of inducing cerebral hemorrhage has been documented. OBJECTIVE: We investigated the effect of the administration of BC05, which was the first antibody developed against the carboxyl (C)-termini of Abeta42(43), on the clearance of brain Abeta42(43). METHOD: The BC05 antibody was injected into the peritoneal cavity of Tg2576 transgenic mice expressing betaAPP(KM670/671NL) once a week from 3 to 12 months of age. RESULTS: BC05 caused a selective 44-fold increase in plasma Abeta42(43) and a significant increase in brain soluble Abeta42(43), showing a 156% difference. Brain insoluble Abeta40 and Abeta42(43) levels were decreased by 27.3 and 31.5%, respectively. A reduction in the number of BAN50-labeled plaques was observed. CONCLUSIONS: BC05 might render Abeta42(43) soluble within the brain and inhibit the insoluble deposition of Abeta40 and Abeta42(43). By analyzing the mechanism of the elevation of soluble Abeta42(43) after passive immunization of BC05, safer and more effective methods of immunotherapy for Alzheimer's disease might be developed.

Alzheimer Disease↗
PubMed2005

[The advantage of our original straight cannula for tracheostoma].

Patients with head and neck cancers often require use of a tracheal cannula due to stenosis of the permanent tracheostoma following total laryngectomy. However, a cannula that is designed for a multi-purpose tracheotomy frequently presents a problem, when placed in a permanent tracheostoma. To resolve this difficulty, we developed a straight cannula that fits most permanent tracheostomas. We achieved a straight design by removing the curvature of a cuffed tracheostomy single cannula (size 12: Koken Co., Ltd.). To facilitate installation by the patient without assistance, silicone was used because it is softer than similar conventional products. By making the cannula diameter slightly larger, immobilization with a strap is lomger needed. Our cannula was used in 14 patients following surgery for the laryngeal, hypopharyngel, esophageal carcinomas. The cannula fit well and reduced the respiratory discomfort in all patients.

Aged↗
PubMed2005

[Prognostic value of serum markers for liver fibrosis in transient abnormal myelopoiesis (TAM)].

Transient abnormal myelopoiesis (TAM) is usually a self-limiting myeloproliferative disorder observed in approximately 10% of newborn infants with Down syndrome. However, progressive liver fibrosis may occur in patients with TAM and is often lethal. We investigated the utility of the serum levels of hyaluronic acid (HA) and N-terminal peptide of III procollagen (P-III-P) as markers of liver fibrosis and indication for chemotherapy. We reviewed 4 cases of TAM retrospectively. HA levels were more than one hundred times as high as the upper limit of the normal range in 2 patients, one of whom died from gastrointestinal bleeding. His HA and P-III-P had increased up to 18,800 U/ml and 26.2 ng/ml, respectively, just before he died. Another patient's serum HA and P-III-P increased to 6,100 U/ml and 12.8 ng/ml, respectively, however his liver fibrosis resolved with low-dose cytosine arabinoside treatment after exchange transfusion during his clinical course. We suggest that serum HA is useful as a marker of liver fibrosis and a prognostic indicator for chemotherapy in patients with TAM. Early treatment including both exchange transfusion and chemotherapy should be considered for patients presenting with extremely high or an elevating tendency of their HA serum levels.

Biomarkers↗
PubMed2004

Crystallization and preliminary X-ray analysis of coagulation factor IX-binding protein from habu snake venom at pH 6.5 and 4.6.

Coagulation factor IX-binding protein isolated from Trimeresurus flavoviridis (IX-bp) is a C-type lectin-like protein. It is an anticoagulant protein consisting of homologous subunits A and B. The subunits both contain a Ca2+-binding site with differing affinity (Kd values of 14 and 130 microM at pH 7.5). These binding characteristics are pH-dependent; under acidic conditions, the affinity of the low-affinity site was reduced considerably. In order to identify which site has high affinity and also to investigate the Ca2+-releasing mechanism, IX-bp was crystallized at pH 6.5 and 4.6. The crystals at pH 6.5 and 4.6 diffracted to 1.72 and 2.29 A resolution, respectively; the former crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 60.7, b = 63.5, c = 66.9 A, beta = 117.0 degrees, while the latter belong to the monoclinic space group C2, with a = 134.1, b = 37.8, c = 55.8 A, beta = 110.4 degrees.

Animals↗
PubMed2004

More rapid evaluation of biomacromolecular crystals for diffraction experiments.

The parameters used to evaluate biomacromolecular crystal quality [Rmerge, I/sigma(I), maximum resolution and mosaicity] strongly depend on the experimental diffraction conditions. In this paper, the distinctive features of the relative Wilson plot method are described and it is shown that the overall B factor obtained from this plot is more appropriate for the characterization of protein crystals. The relative Wilson plot has been applied to the characterization of crystals of the B-DNA decamer d(CCATTAATGG) and crystals of the proteins DsrD (dissimilatory sulfite reductase D) and hen egg-white lysozyme (HEWL), which were studied by neutron diffraction. It was found that the crystal quality of the B-DNA decamer and DsrD depended significantly on the regions of the crystallization phase diagram from which the samples were taken. However, in the case of HEWL crystal quality appears to be independent of the region of the crystallization phase diagram.

Animals↗
PubMed2004

Complete genome sequence of Mycoreovirus-1/Cp9B21, a member of a novel genus within the family Reoviridae, isolated from the chestnut blight fungus Cryphonectria parasitica.

Mycoreovirus 1 (MYRV-1) is the type species of the newly described genus Mycoreovirus of the large virus family Reoviridae. The virus was isolated from a hypovirulent strain (9B21) of the chestnut blight fungus, Cryphonectria parasitica. A previous study showed that double-shelled particles introduced to fungal spheroplasts resulted in stably infected colonies. Of the 11 double-stranded RNA genomic segments (S1-S11), the three largest (S1-S3) were sequenced previously and shown to have moderate levels of similarity to the homologous segments of mammal-pathogenic coltiviruses (Eyach virus and Colorado tick fever virus) and another fungus-infecting reovirus, Mycoreovirus 3 of Rosellinia necatrix strain W370 (MYRV-3/RnW370). The sequences of the remaining segments (S4-S11) are reported here. All of the segments have single ORFs on their positive strands and the terminal sequences 5'-GAUCA----GCAGUCA-3' are conserved among currently and previously sequenced segments. Oligo-cap analysis showed that the positive strands of the genomic segments are capped, whereas the negative strands are not. Similarities among the four evolutionarily related viruses include low or moderate levels of amino acid sequence identity (14.7-34.2 %) and isoelectric points among equivalent polypeptides, e.g. proteins encoded by segments S4 and S5 of the four viruses. Phylogenetic analysis indicated that MYRV-1/Cp9B21 is related more closely to MYRV-3/RnW370 than to the coltiviruses. An interesting dissimilarity is found in codon-choice pattern among the four viruses, i.e. MYRV-1/Cp9B21 segments have a lower frequency of [XYG+XYC] than corresponding segments of the other viruses, suggesting a possible adjustment of virus codon usage to their host environments.

Amino Acid Sequence↗
PubMed2004

A reovirus of the fungus Cryphonectria parasitica that is infectious as particles and related to the coltivirus genus of animal pathogens.

RNA viruses of filamentous fungi fall into two broad categories, those that contain double-stranded RNA (dsRNA) genomes in rigid particles and those that are more closely related to positive-sense, single-stranded RNA viruses with dsRNA replicative intermediates found within lipid vesicles. Effective infectivity systems have been described for the latter, using RNA transcripts, but not for the former. We report the characterization of a reovirus from Cryphonectria parasitica, the filamentous fungus that causes chestnut blight disease. The virus substantially reduces the virulence of the fungus and results in dramatically altered colony morphology, as well as changes in other associated fungal traits, relative to the virus-free isogenic strain. Virus particles from infected mycelium contained 11 segments of dsRNA and showed characteristics typical of the family Reoviridae. Sequences of the largest three segments revealed that the virus is closely related to the Coltivirus genus of animal pathogens, which includes the human pathogen Colorado tick fever virus. The introduction of purified virus particles into protoplasts from virus-free isolates of the fungus resulted in a newly infected mycelium with the same morphology and virus composition as the original virus-infected isolate. This represents the completion of Koch's postulates for a true dsRNA virus from a filamentous fungus and the description of a definitive fungal member of the family Reoviridae.

Ascomycota↗
PubMed2003

Identification of urotensin II-related peptide as the urotensin II-immunoreactive molecule in the rat brain.

Urotensin II (UII) has been reported as the most potent known vasoconstrictor. While rat and mouse orthologs of UII precursor protein have been reported, only the tentative structures of UII peptides of these animals have been demonstrated, since prepro-UII proteins lack typical processing sites for their mature peptides. In the present study, we isolated a novel peptide, UII-related peptide (URP), from the extract of the rat brain as the sole immunoreactive substance to anti-UII antibody; the amino acid sequence of the peptide was determined as ACFWKYCV. cDNAs encoding rat, mouse, and human precursor proteins for URP were cloned and revealed that the sequences of mouse and human URP peptides are the same as that for rat URP. Prepro-URP gene is expressed in several rat tissues such as those of the thymus, spleen, testis, and spinal cord, although with lower levels than the prepro-UII gene. In the human, the prepro-URP gene is expressed comparably to prepro-UII in several tissues except the spinal cord. URP was found to bind and activate the human or rat UII receptors (GPR14) and showed a hypotensive effect when administered to anesthetized rats. These results suggest that URP is the endogenous and functional ligand for UII receptor in the rat and mouse, and possibly in the human. We also describe the preparation of specific monoclonal antibodies raised against UII peptide and the establishment of a highly sensitive enzyme immunoassay system for UII peptides.

Amino Acid Sequence↗
PubMed2003

Production of recombinant human relaxin 3 in AtT20 cells.

Relaxin 3 has been reported recently as a member of the insulin/IGF/relaxin family. To clarify the function of relaxin 3, we prepared recombinant human relaxin 3 using a mouse adrenocorticotrophic hormone (ACTH)-secreting cell line, AtT20. To detect a mature form of recombinant human relaxin 3, a competitive enzyme immunoassay (EIA) was developed using a monoclonal antibody (mAb; HK4-144-10), which was raised for the N-terminal peptide of human relaxin 3 A-chain. We detected immunoreactive (ir-) relaxin 3 in the culture supernatant of AtT20 cells stably transfected with human relaxin 3 cDNA. After treatment with 5 microM forskolin for 3 days, the concentration of the ir-relaxin 3 in the culture supernatant reached 12 nM. Ir-relaxin 3 was purified from the culture supernatant by a combination of various chromatographies. By analyses of N-terminal amino acid sequence and electrospray ionization mass spectrometry (ESI-MS), we confirmed that the purified material was a mature form of human relaxin 3. The recombinant human relaxin 3 thereby obtained increased intracellular cAMP production in THP-1 cells. Our results demonstrate that the expression of relaxin 3 cDNA in AtT20 cells is a useful tool to produce a bioactive and mature form of relaxin 3.

Amino Acid Sequence↗
PubMed2003

Discovery of a thieno[2,3-d]pyrimidine-2,4-dione bearing a p-methoxyureidophenyl moiety at the 6-position: a highly potent and orally bioavailable non-peptide antagonist for the human luteinizing hormone-releasing hormone receptor.

We have previously disclosed the first potent and orally effective non-peptide antagonist for the human luteinizing hormone-releasing hormone (LHRH) receptor, a thieno[2,3-b]pyridin-4-one derivative, T-98475 (1). Extensive research on developing non-peptide LHRH antagonists has been carried out by employing a strategy of replacing the thienopyridin-4-one nucleus with other heterocyclic surrogates. We describe herein the design and synthesis of a series of thieno[2,3-d]pyrimidine-2,4-dione derivatives containing a biaryl moiety, which led to the discovery of a highly potent and orally active non-peptide LHRH antagonist, 5-(N-benzyl-N-methylaminomethyl)-1-(2,6-difluorobenzyl)-6-[4-(3-methoxyureido)phenyl]-3-phenylthieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (9k: TAK-013). Compound 9k showed high binding affinity and potent in vitro antagonistic activity for the human receptor with half-maximal inhibition concentration (IC(50)) values of 0.1 and 0.06 nM, respectively. Oral administration of 9k caused almost complete suppression of the plasma LH levels in castrated male cynomolgus monkeys at a 30 mg/kg dose with sufficient duration of action (more than 24 h). The results demonstrated that the thienopyrimidine-2,4-dione core is an excellent surrogate for the thienopyridin-4-one and that thienopyrimidine-2,4-diones and thienopyridin-4-ones constitute a new class of potent and orally bioavailable LHRH receptor antagonists. Furthermore, molecular modeling studies indicate that the unique methoxyurea side chain of 9k preferentially forms an intramolecular hydrogen bond between the aniline NH and the methoxy oxygen atom. The hydrogen bond will shield the hydrogen bonding moieties from the solvent and reduce the desolvation energy cost. It is therefore speculated that the intramolecular hydrogen bond resulting from judicious incorporation of an oxygen atom into the terminal alkyl group of the urea may increase the apparent lipophilicity to allow increased membrane permeability and consequently to improve the oral absorption of 9k in monkeys. On the basis of its profile, compound 9k has been selected as a candidate for clinical trials and it is expected that it will provide a new class of potential therapeutic agents for the clinical treatment of a variety of sex-hormone-dependent diseases.

Administration, Oral↗
PubMed2003

Successful cidofovir treatment of adenovirus-associated hemorrhagic cystitis and renal dysfunction after allogenic bone marrow transplant.

We present a patient who developed hemorrhagic cystitis and renal dysfunction after unrelated bone marrow transplantation. Polyoma BK virus and adenovirus 11 were detected in the urine. Vidarabine was administered without effect. Relatively low dose cidofovir was efficacious. Renal function improved, and the urinary secretion of adenovirus stopped.

Acute Kidney Injury↗
PubMed2003

Hypovirus papain-like protease p29 functions in trans to enhance viral double-stranded RNA accumulation and vertical transmission.

The prototypic hypovirus CHV1-EP713 attenuates virulence (hypovirulence) and alters several physiological processes of the chestnut blight fungus Cryphonectria parasitica. The papain-like protease, p29, and the highly basic protein, p40, derived, respectively, from the N-terminal and C-terminal portions of the CHV1-EP713-encoded open reading frame (ORF) A polyprotein, p69, both contribute to reduced pigmentation and sporulation. The p29 coding region was shown to suppress pigmentation and asexual sporulation in the absence of virus infection in transformed C. parasitica, whereas transformants containing the p40-coding domain exhibited a wild-type, untransformed phenotype. Deletion of either p29 or p40 from the viral genome also results in reduced accumulation of viral RNA. We now show that p29, but not p40, functions in trans to enhance genomic RNA accumulation and vertical transmission of p29 deletion mutant viruses. The frequency of virus transmission through conidia was found to decrease with reduced accumulation of viral genomic double-stranded RNA (dsRNA): from almost 100% for wild-type virus to approximately 50% for Deltap29, and 10 to 20% for Deltap69. When expressed from a chromosomally integrated cDNA copy, p29 elevated viral dsRNA accumulation and transmission for Deltap29 mutant virus to the level shown by wild-type virus. Increased viral RNA accumulation levels were also observed for a Deltap69 mutant lacking almost the entire ORF A sequence. Such enhancements were not detected in transgenic fungal colonies expressing p40. Mutation of p29 residues Cys(70) or Cys(72), strictly conserved in hypovirus p29 and potyvirus HC-Pro, resulted in the loss of both p29-mediated suppressive activity in virus-free transgenic C. parasitica and in trans enhancement of RNA accumulation and transmission, suggesting a linkage between these functional activities. These results suggest that p29 is an enhancer of viral dsRNA accumulation and vertical virus transmission through asexual spores.

Ascomycota↗
PubMed2003

Suppression of a pituitary-ovarian axis by chronic oral administration of a novel nonpeptide gonadotropin-releasing hormone antagonist, TAK-013, in cynomolgus monkeys.

TAK-013 is a novel nonpeptide and orally active GnRH antagonist. We first examined the effect of TAK-013 on GnRH-stimulated LH release using primary-cultured pituitary cells of cynomolgus monkeys. TAK-013 suppressed LH release to below basal levels at concentrations higher than 100 nM with the IC(50) value of 36 nM. Next, we examined the effect of chronic oral administration of TAK-013 on serum hormone levels in regularly cycling female cynomolgus monkeys. TAK-013 administered at 90 mg/kg x d (30 mg/kg 3 times daily) for approximately 80 d continued to suppress LH, estradiol, and progesterone, but not FSH. The suppressive effect was reversible, in that normal profiles of sex steroids were observed immediately after discontinuation of the TAK-013 treatment. Interestingly, the suppressive effect of TAK-013 was not observed in marmoset monkeys. In summary, TAK-013 by oral administration suppresses a pituitary-ovarian axis continuously and reversibly in cynomolgus monkeys. Considering that TAK-013 has more potent antagonistic properties for human GnRH receptor than for monkey receptor, our data suggest that TAK-013 would be effective for reproductive disorders such as endometriosis and uterine leiomyoma and useful for assisted reproductive technology procedures.

Animals↗
PubMed2002

Distribution of PACAP and its mRNA in several nonneural tissues of rats demonstrated by sandwich enzyme immunoassay and RT-PCR technique.

The presence of PACAP in various organs was previously demonstrated using immunohistochemistry and radioimmunoassay. The aim of our work was to get information whether the presence of immunoreactive PACAP in various organs, mainly in the gastric mucosa, also indicates the place of its synthesis. The immunoreactive PACAP and its mRNA were measured in parallel assays using sandwich enzyme immunoassay (S-EIA) and RT-PCR technique. PACAP and its mRNA were demonstrated in the pancreas, testes, adrenal glands, ovaries, and in the oxyntic mucosa of the stomach. These results support our previous observation that PACAP is present not only in the nervous system and endocrine glands, but might be synthetized in the oxyntic mucosa of the stomach as well.

Adrenal Glands↗
PubMed2002

A new class of potent nonpeptide luteinizing hormone-releasing hormone (LHRH) antagonists: design and synthesis of 2-phenylimidazo[1,2-a]pyrimidin-5-ones.

The design and synthesis of a new class of nonpeptide luteinizing hormone-releasing hormone (LHRH) receptor antagonists, the 2-phenylimidazo[1,2-a]pyrimidin-5-ones, is reported. Among compounds described in this study, we identified the potent antagonist 15b with nanomolar in vitro functional antagonism. The result might suggest that the heterocyclic 5-6-ring system possessing a pendant phenyl group attached to the five-membered ring is the important structural feature for a scaffold of small molecule LHRH antagonists.

Binding, Competitive↗