Biomedical subjects

H Matsuyama

Publications and source records attributed to H Matsuyama.

At least 37 records · Page 2Linked to original sources

PubMed2001

Deletions on chromosome 8p22 may predict disease progression as well as pathological staging in prostate cancer.

PURPOSE: A recent report demonstrated that the deletion of chromosome 8p22 could predict disease progression in stage III (capsular penetrating) prostate cancer. We studied if the status of chromosomal deletions of 8p22 could reflect pathological stage as well as patient prognosis, thereby serving as a diagnostic tool to optimize the treatment strategy in prostate cancer. EXPERIMENTAL DESIGN: A total of 97 patients (41 Japanese and 56 Swedish) were studied by the fluorescence in situ hybridization technique. Seventy-seven patients (23 pT2, 18 pT3, and 36 pN+ tumors) underwent surgery (radical prostatectomy or lymph node dissection). The specimens were prepared by touch biopsy. From another 20 cases, fine-needle aspiration biopsies were obtained. RESULTS: 8p22 deletions were detected in 47 (61%) and 11 (55%) specimens of 77 touch biopsies and 20 fine-needle aspiration biopsies, respectively. No significant difference was found in the frequency of 8p22 deletion between different preparations of specimens, as well as between different races (Japanese versus Swedish). The frequency of 8p22 deletion was statistically higher in patients with pT3 or more than in those with pT2 (P < 0.01). Disease progression was evaluated in 57 patients. The Cox proportional hazards model revealed 8p22 deletion to be the strongest parameter to predict disease progression (hazards ratio = 5.75; P = 0.0001). CONCLUSIONS: Studies on chromosomal deletions of 8p22 by fluorescence in situ hybridization technique may serve as a genetic marker to optimize the treatment strategy in patients with prostate cancer to the optimal treatment.

Aged↗

PubMed2000

all-Z-Tetrabenzo

Crystal structures of the silver complexes derived from tetrabenzo[16]annulene with AgOTf and AgClO(4) are different, although these two complexes show similar (1)H NMR spectra reflecting a similar clathrate structure in solution. The silver complex of pentabenzo[20]annulene with AgClO(4) adopts a clathrate structure both in the solid state and in solution.

Journal Article↗

PubMed2000

Bradykinin causes endothelium-independent hyperpolarisation and neuromodulation by prostanoid synthesis in hamster mesenteric artery.

The mechanism of bradykinin-induced hyperpolarisation and purinergic neuromodulation was examined in the hamster superior mesenteric artery using intracellular microelectrode techniques. Bradykinin induced a concentration-dependent hyperpolarisation both in endothelium-intact and -denuded preparations. Indomethacin blocked this hyperpolarisation. Prostacyclin and iloprost also hyperpolarised the membrane of mesenteric artery, while prostaglandin E(2) did not evoke any membrane hyperpolarisation. The bradykinin-, prostacyclin- and iloprost-induced hyperpolarisation were inhibited by glibenclamide. Bradykinin also inhibited the amplitude of the purinergic excitatory junction potentials (e.j.p.s), both in endothelium-intact and -denuded preparations. Indomethacin blocked this inhibitory effect. Prostaglandin E(2) inhibited the e.j. p. in a concentration-dependent manner. Focally applied ATP-induced depolarisation was not modified by bradykinin or prostaglandin E(2.) These findings suggest that bradykinin via prostanoids production pre-synaptically, inhibit the amplitude of purinergic e.j.p., resulting inhibitory purinergic neuromodulation. In addition, bradykinin-released prostanoids elicits membrane hyperpolarisation of smooth muscle cells through opening of K(ATP) channels.

Adenosine Triphosphate↗

PubMed2000

Synthesis of fischer-type (Alkoxy)carbene complexes using diphenylsulfonium salts with functionalized alkyl groups

A new and general method for preparing Fischer-type alkoxycarbene complexes 1 is reported. This method involves the alkylation of acylate complexes 7 with alkyldiphenylsulfonium salts 10 with a variety of functionalized alkyl groups. The alkylation of tetramethylammonium pentacarbonyl(1-oxyalkylidene)chromate(0) 7a-c, tetramethylammonium pentacarbonyl(1-oxymethylidene)molybdate(0) 7d, and pentacarbonyl(1-oxymethylidene)tungstate(0) 7e with alkyldiphenylsulfonium salts 10 proceeded smoothly under mild conditions to give the corresponding alkoxycarbene complexes 12-39 in good to high yields. Competitive alkylation of 7a with methyl-11 and isopropyldiphenylsulfonium tetrafluoroborate 40 shows a higher reactivity of the isopropyl group, suggesting the participation of an S-O sulfurane intermediate 41.

Journal Article↗

PubMed2000

Microscopic imaging of Fe magnetic domains exchange coupled with those in a NiO(001) surface.

We revealed the micromagnetic structure of an Fe thin film exchange interacting with the spins of a fully compensated (001) surface of antiferromagnetic NiO. The interface exchange interaction causes the Fe domains to follow the NiO domains. The Fe spin polarization is in plane and the spin polarization in each domain is roughly perpendicular to an easy-spin axis of the NiO. These results agree with numerically calculated spin directions. Our numerical results also show that the NiO spins at the interface cant from the easy-spin axis towards the Fe spin because of exchange coupling.

Journal Article↗

PubMed2000

A cyclic oligophenylene containing two 1,8-naphthalene units bridged by two face-to-face biphenyl linkages exhibiting unusual strain and pi-pi interaction

1,8-[1,8-Naphthalenediylbis(4',4-biphenyldiyl)]naphthalene, a very stable strained cyclophane, has been synthesized in moderate yield using the copper-catalyzed coupling of 1, 8-bis(4-(tributylstannyl)phenyl)naphthalene. The X-ray analysis of the titled compound discloses bent p,p'-biphenylylene chains with splayed naphthalene rings, and the p,p'-biphenylylene chains located face-to-face indicate a fairly strong pi-pi interaction.

Journal Article↗

PubMed2000

Reaction of selenobenzophenones with olefins. Formation of 1H-2-benzoselenopyrans. Reaction of 1H-2-benzoselenopyrans with diazoalkanes

Selenobenzophenone reacts as a diene with dimethyl acetylenedicarboxylate (DMAD) to lead to dimethyl 1H-1-diphenylmethyl-1-phenyl-2-benzoselenopyran-3,4-dicarboxylate (5c) in moderate yield; the initial [4 + 2] cycloaddition is followed by the addition of another 1 mol equiv of selenobenzophenone. The reaction might proceed through carbene insertion of the primary cycloadduct. On the other hand, 4,4'-dimethoxyselenobenzophenone combines as a diene with DMAD furnishing dimethyl 1H-1-p-methoxyphenyl-6-methoxy-2-benzoselenopyran-3,4-dicarboxylate (4a). The reaction of benzoselenopyran derivative (4) with diaryldiazomethanes afforded another type of carbene insertion product.

Journal Article↗

PubMed2000

Diagnostic value of prostate-specific antigen-related parameters in discriminating prostate cancer.

BACKGROUND: Using the percentage (of total) of free prostate-specific antigen (PSA) in discriminating prostate cancer (CaP) from benign prostate hyperplasia (BPH) has not been fully delineated in Japanese men. To clarify the clinical significance of percent free PSA, various parameters, including total prostate volume, percent free PSA, PSA density (PSAD) and PSA density of transition zone volume (PSAT), were compared. METHODS: Ninety-seven patients who had visited one of three community-based hospitals, and whose total PSA value ranged from 4 to 20 ng/mL were prospectively enrolled in this study. Fresh sera were applied to measure the percent free PSA. RESULTS: Of the 97 patients, CaP and BPH were diagnosed in 24 (25%) and 73 patients, respectively. In discriminating CaP patients, the cutoff values of 17% for percent free PSA, 0.3 ng/mL per cm3 for PSAT, and 0.19 ng/mL per cm3 for PSAD yielded specificity levels of 56, 40 and 58% at sensitivity levels of 92, 92 and 79%, respectively. As for the 65 patients with intermediate PSA, range 410 ng/mL, and normal digital rectal examination, the percent free PSA and total prostate volume statistically discriminated CaP patients from BPH patients. A multiple logistic regression model proved percent free PSA to be the only significant discriminating factor (P=0.045; odds ratio, 9.06). CONCLUSIONS: This prospective study revealed percent free PSA to be a significant useful predictor in discriminating CaP from BPH in Japanese men.

Aged↗

PubMed2000

Purification and characterization of a catalase from the facultatively psychrophilic bacterium Vibrio rumoiensis S-1(T) exhibiting high catalase activity.

Catalase from the facultatively psychrophilic bacterium Vibrio rumoiensis S-1(T), which was isolated from an environment exposed to H(2)O(2) and exhibited high catalase activity, was purified and characterized, and its localization in the cell was determined. Its molecular mass was 230 kDa, and the molecule consisted of four identical subunits. The enzyme, which was not apparently reduced by dithionite, showed a Soret peak at 406 nm in a resting state. The catalytic activity was 527,500 U. mg of protein(-1) under standard reaction conditions at 40 degrees C, 1.5 and 4.3 times faster, respectively, than those of the Micrococcus luteus and bovine catalases examined under the same reaction conditions, and showed a broad optimum pH range (pH 6 to 10). The catalase from strain S-1(T) is located not only in the cytoplasmic space but also in the periplasmic space. There is little difference in the activation energy for the activity between strain S-1(T) catalase and M. luteus and bovine liver catalases. The thermoinstability of the activity of the former catalase were significantly higher than those of the latter catalases. The thermoinstability suggests that the catalase from strain S-1(T) should be categorized as a psychrophilic enzyme. Although the catalase from strain S-1(T) is classified as a mammal type catalase, it exhibits the unique enzymatic properties of high intensity of enzymatic activity and thermoinstability. The results obtained suggest that these unique properties of the enzyme are in accordance with the environmental conditions under which the microorganism lives.

Amino Acids↗

PubMed2000

Clinical usefulness of intravenous albunex for the Doppler assessment of aortic stenosis.

Optimal Doppler recordings of stenotic aortic flow are not always easy to obtain. Therefore, the present study investigated how useful intravenous Albunex injections were for improving the Doppler assessment of pressure gradients for aortic stenosis in 20 consecutive patients who underwent Doppler and left-heart catheterization studies within a 1-week period. Continuous-wave Doppler echocardiography was performed using both a 2.5 MHz duplex and a 1.9MHz independent transducer before and after Albunex injections. The maximum and mean pressure gradients were calculated from the highest Doppler velocity tracings using the simplified Bernoulli equation. Pullback catheterization pressure tracings from the left ventricle to the ascending aorta were superimposed for determination of the maximum instantaneous and mean pressure gradients. The Doppler-derived peak and mean pressure gradients showed significant underestimation compared with the catheterization gradients (23+/-17 mmHg and 11+/-7 mmHg, respectively). However, this underestimation disappeared with Albunex injection (-2+/-7 mmHg and -1+/-4mmHg, respectively). Although the Doppler-derived instantaneous and mean pressure gradients correlated well with the catheterization gradients (r=0.909 and r=0.879, respectively), they became much closer with Albunex (r=0.987 and r=0.963, respectively). The improvements in the Doppler-derived peak pressure gradients were significant from an apical window (n=12, 84-120mmHg, p<0.001). but less so from non-apical windows (n=8, 84-91 mmHg, p=0.0146). Accordingly, Albunex is most useful for Doppler recordings of stenotic aortic flow available from the apical window, but not less so from other acoustic windows.

Adult↗

PubMed1999

ATP released from perivascular nerves hyperpolarizes smooth muscle cells by releasing an endothelium-derived factor in hamster mesenteric arteries.

1. The interaction between perivascular nerves and endothelium was investigated by measuring the changes in smooth muscle membrane potentials using intracellular microelectrode techniques in hamster mesenteric thin (100-150 microm) and thick (300-350 microm) arteries. 2. In both arteries, nerve stimulation evoked excitatory junction potentials (EJPs) which were strongly inhibited by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) (0.5-5 microM). This result indicated that the EJPs were induced by the activation of P2X receptors. 3. Transient hyperpolarizations were evoked by trains of pulses at 20 Hz in PPADS (5 microM)-pre-treated thin arteries, but not in the thick arteries. ATP (100 microM) applied to adventitial surfaces mimicked the hyperpolarizations. Both the ATP- and nerve stimulation-induced hyperpolarizations were blocked by cibacron blue F3GA (2-100 microM) and were also abolished after endothelium removal, indicating that the neurally released ATP evoked transient hyperpolarization through the activation of P2Y receptors located on the endothelium. 4. In endothelium-intact preparations, intimal application of uridine 5'-triphosphate (UTP 100 microM), a P2Y2-like receptor agonist, but not 2-methylthio ATP (7 microM), hyperpolarized the smooth muscle. The UTP-induced hyperpolarization was significantly inhibited by cibacron blue F3GA and was abolished after endothelium removal. 5. These results suggest that ATP released from the perivascular nerves may reach the endothelium and activate P2Y2-like receptors to induce the release of an endothelium-derived hyperpolarizing factor in thin arteries.

Adenosine Triphosphate↗

PubMed1999

Links between genetic and environmental factors and prostate cancer risk.

BACKGROUND: Genetic polymorphisms and expression of steroid receptors may explain why some individuals are more at risk of developing prostate cancer. Some risk factors often discussed are androgen stimulation, and vitamin A and D deficiency. Long CAG-repeats in exon 1 of the androgen receptor (AR) gene on the X chromosome seem to have a protective role against androgen overstimulation. Likewise, long vitamin D receptor alleles in the poly-A tract may prevent vitamin D stimulation. METHODS: Blood samples from 59 Swedish patients with sporadic prostate cancers, 59 with hereditary prostate cancer, and 34 Japanese prostate cancer patients were compared with benign controls. Tissue specimens from 37 Swedish and 23 Japanese prostate cancer patients with matching blood samples were investigated by immunohistochemical techniques. RESULTS: The number of CAG-repeats was identical in sporadic and hereditary prostate cancer patients, but the repeats were significantly shorter than in benign controls. Benign Japanese controls were similar to Swedish controls, but Japanese prostate cancers had longer repeats than did controls. Both the vitamin D and A receptor staining was stronger in Japanese than in Swedish prostate cancer specimens. Prostate cancer occurs approximately 5 years later in Japanese compared with Swedish men. CONCLUSIONS: Varying lengths of CAG-repeats of the androgen receptor cannot fully explain racial differences in clinical prostate cancer incidence. A larger content of vitamin A and D receptors may be linked to a delayed onset of clinical prostate cancer in Japanese men.

Asian People↗

PubMed1999

Immunohistochemical evaluation of the marbled state in childhood hypoxic encephalopathy.

We have immunohistochemically analyzed the marbled state in 8 cases of perinatal hypoxic ischemic encephalopathy and 4 cases of infantile hypoxic encephalopathy, using antibodies against calbindin-D28k (CaBD), glial fibrillary acidic protein (GFAP), methionine-enkephalin (MEnk), myelin basic protein (MBP), neurofilament (NF), parvalbumin (PV), substance-P (SuP) and synaptophysin (SP). The marbled state was found in the thalamus in 11 cases, whose age at death was over 10 years. Four cases demonstrated the marbled state in the cerebral cortex, in addition to the striatum and/or the thalamus. The abnormally myelinated fibers in the marbled state were stained with both Kluver-Barrera and Holzer stainings; however, they were partly immunopositive for MBP and completely immunonegative for GFAP, CaBD, MEnk, PV, SuP and SP, although some of the neurons and/or fibers showed immunoreactivities for those calcium-binding proteins and/or neurotransmitters. The axons were visualized in the abnormally myelinated fibers by Bodian staining and/or anti-NF immunostainings in the cerebral cortex and striatum but not in the thalamus. GFAP-positive astrocytes did not show any continuity with the abnormally myelinated fibers. These histological features were seen in the cerebral cortex, striatum and thalamus. Difference of the etiology did not affect the histological features with the exception of anti-PV staining, in which PV-immunopositive neurons were observed only in aged subjects with infantile hypoxic encephalopathy, and seemed to be more severely affected by hypoxic stress during the perinatal period than the early infantile period. These data suggest that the site of lesion or the length of survival period after brain injury might influence the formation of the marbled state rather than the etiology. And the direct relationship between the abnormally myelinated fiber and astrocytic process was not verified.

Adolescent↗

PubMed1999

Production of a novel exopolysaccharide by Rahnella aquatilis.

A bacterium Tomakomai B-1 that was isolated from the activated sludge of a treatment process for wastewater of the pulp industry was found to produce soluble and insoluble exopolysaccharides (EPSs) when grown aerobically in a medium containing sucrose as the sole carbon source. The sugar component of soluble EPSs consisted of rhamnose, mannose, galactose, glucose, mannuronic acid, galacturonic acid and glucuronic acid, and that of insoluble EPSs consisted of rhamnose, mannose, galactose, glucose, mannuronic acid and glucuronic acid. The concentrations of insoluble and soluble EPS were approximately 1.63 and 2.58 g/l, respectively, by Erlenmeyer flask culture at 20 degrees C for 3 d with a synthetic medium containing 1% sucrose, 0.05% CaCO(3), 0.05% MgSO(4), 0.1% K(2)HPO(4), 0.0001% Na(2)MoO(4), 0.01% urea, 1.07% MES and small amounts of trace metals. Tomakomai B-1 was identified as Rahnella aquatilis. To our knowledge the production of EPSs by R. Aquatilis is reported here for the first time.

Journal Article↗

PubMed1999

Cyclic GMP-associated apamin-sensitive nitrergic slow inhibitory junction potential in the hamster ileum.

1. The mediators of non-adrenergic, non-cholinergic (NANC) inhibitory junction potentials (i.j.ps) in the circular smooth muscle cells of the hamster ileum were studied. 2. Electrical field stimulation (EFS; 0.5 ms duration, 15 V) of the intramural nerves with a train of five pulses at 20 Hz evoked a rapidly developing hyperpolarization (fast i.j.p.) followed by a sustained hyperpolarization (slow i.j.p.). 3. NG-nitro-L-arginine methyl ester (L-NAME; 50 - 200 microM) and NG-nitro-L-arginine (L-NNA; 50 - 200 microM), NO synthase inhibitors, inhibited or abolished the EFS-induced fast and slow NANC i.j.ps. The effects of these NO synthase inhibitors were reversed by L-arginine (5 mM) but not by D-arginine (5 mM). 4. Exogenously applied nitric oxide (NO; 1 - 100 microM) induced concentration-dependent hyperpolarizations. 5. Oxyhaemoglobin (5 - 50 microM), NO scavenger, inhibited only the slow i.j.p., and the NO-induced hyperpolarization. 6. 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxaline-1-one (ODQ; 10 microM) and cystamine (10 mM), guanylate cyclase inhibitors, inhibited only the slow i.j.p. Zaprinast (100 microM), a phosphodiesterase type V inhibitor, enhanced the amplitude and duration of the slow i.j.p. 7. Apamin (100 nM), a small conductance Ca2+-activated K+ channel blocker, inhibited only the slow i.j.p., and NO-induced hyperpolarization. A high concentration of 8-bromoguanosine 3':5'-cyclic monophosphate (8-bromo-cGMP; 1 mM)-induced membrane hyperpolarization which was blocked by apamin. 8. These results suggest that NO, or a related compound, may be the inhibitory transmitter underlying the apamin-sensitive NANC slow i.j.p. and cyclic GMP mediates the slow i. j.p. in the hamster ileum. It is also likely that NO, without involvement of guanylate cyclase is associated with the fast i.j.p.

Animals↗

PubMed1999

Microbacterium kitamiense sp. nov., a new polysaccharide-producing bacterium isolated from the wastewater of a sugar-beet factory.

Two strictly aerobic, heterotrophic and mesophilic new organisms, strains Kitami A1 and Kitami C2T, were isolated from the wastewater of a sugar-beet factory in Kitami City, Hokkaido, Japan. In batch cultures, these organisms produced both insoluble and soluble exopolysaccharides (EPSs) utilizing sucrose as the sole carbon source. The G + C contents of the strains Kitami C2T and Kitami A1 were 69.2 mol%. Both strains had anteiso-C15:0 acid, anteiso-C17:0 acid and iso-C16:0 as major components. The major isoprenoid quinones from these strains included menaquinone-11 and menaquinone-12. Physiological and biochemical characterization, phylogenetic analysis and DNA-DNA relatedness indicated that these two organisms are new species of the genus Microbacterium, for which the name Microbacterium kitamiense is proposed. The type strain of M. kitamiense is strain Kitami C2T (= JCM 10270T).

Actinomycetales↗

PubMed1999

Characterization of a facultatively psychrophilic bacterium, vibrio rumoiensis sp. nov., that exhibits high catalase activity

A novel facultatively psychrophilic bacterium, strain S-1, which exhibits extraordinarily high catalase activity was isolated from the drain pool of a fish product processing plant that uses H2O2 as a bleaching and microbicidal agent. The catalase activity of the isolate was 1 or 2 orders of magnitude higher than those of Corynebacterium glutamicum, Staphylococcus aureus, Pseudomonas fluorescens, and five other species tested in this study. The strain seemed to possess only one kind of catalase, according to the results of polyacrylamide gel electrophoresis of the cell extract. The optimum temperature for catalase activity was about 30 degreesC, which was about 20 degreesC lower than that for bovine catalase activity. Electron microscopic observation revealed that the surface of the microorganism was covered by blebs. Although the isolate was nonflagellated, its taxonomic position on the basis of physiological and biochemical characteristics and analysis of 16S rRNA sequence and DNA-DNA relatedness data indicated that strain S-1 is a new species belonging to the genus Vibrio. Accordingly, we propose the name Vibrio rumoiensis. The type strain is S-1 (FERM P-14531).

Journal Article↗

PubMed1999

Mesalazine-induced eosinophilic pneumonia.

A 35-year-old woman with a 6-month history of ulcerative colitis and treatment with oral mesalazine (5-aminosalicylic acid) developed dry cough, low-grade fever and bilaterally wandering pulmonary infiltrates. Improvement in clinical symptoms and radiological abnormalities occurred spontaneously after discontinuation of mesalazine. The transbronchial lung biopsy demonstrated the organizing stage of eosinophilic pneumonia. Drug lymphocyte stimulation test was positive for mesalazine and negative for sulfasalazine and sulfapyridine. The present case indicates that although mesalazine-induced eosinophilic pneumonia is an extremely rare entity, its possibility should be fully considered in patients developing unexplained respiratory symptoms while on mesalazine therapy.

Adult↗