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Biomedical subjects

N Matsuda

Publications and source records attributed to N Matsuda.

At least 127 records · Page 7Linked to original sources
PubMed1993

Analysis of discordant test results among five second-generation assays for anti-hepatitis C virus antibodies also tested by polymerase chain reaction-RNA assay and other laboratory and clinical tests for hepatitis.

The diagnostic performances of five commercially available second-generation assays for anti-hepatitis C virus antibody, two enzyme-linked immunosorbent assays, one enzyme immunoassay, and two particle agglutination assays (passive hemagglutination assay and particle agglutination assay), were evaluated. Among 104 samples from healthy subjects and 300 consecutive samples from patient ordered for routine determinations of anti-hepatitis C virus antibody in serum, assay results showed variable degrees of discordance for 17 samples (4.2%). These 17 samples were further tested by an immunoblot assay, the polymerase chain reaction-RNA assay, and the hemagglutination inhibition assay. Four of the 17 samples were regarded as true positive, since all supplementary assays and clinical data indicated active hepatitis C virus infection. Another five samples were considered false positive because no confirmatory evidence was obtained from the laboratory analysis or clinical data. The remaining eight samples were negative for hepatitis C virus RNA, but the results of the other supplementary tests were indeterminate. Some of these samples with indeterminate results may have been from patients with subclinical cases of disease who spontaneously recovered from hepatitis with persistent anti-hepatitis C virus antibody in their sera.

Adult↗
PubMed1993

Inhibitory effects of emedastine difumarate on histamine release.

The inhibitory effects of emedastine difumarate on histamine release were studied in rat peritoneal mast cells. Emedastine significantly inhibited substance P (SP)-induced histamine release at concentrations above 10(-9) M in the presence of extracellular Ca2+ and at concentrations above 10(-11) M in its absence. At concentrations of 10(-8) M or higher, emedastine significantly inhibited SP-induced Ca2+ release from intracellular Ca stores and SP-induced 45Ca uptake into mast cells. Emedastine also inhibited passive peritoneal anaphylaxis in rats and guinea pigs. We conclude that the clinical antiallergic effects of emedastine involve the inhibition of histamine release and that this inhibition is mediated by the inhibition of Ca2+ release from intracellular Ca stores and the inhibition of Ca2+ influx into mast cells.

Anaphylaxis↗
PubMed1993

Electron microscopy of influenza virus growth in a human lymphoblastic leukemia cell line, MOLT4 cells.

We studied the interaction of influenza virus and a human lymphoblastic line, MOLT4 cells, as a model for that of influenza virus and human T lymphocytes. Influenza virus was found to grow relatively poorly in MOLT4 cells in terms of yield of plaque forming units (PFU) in the presence of trypsin. However, electron microscopy of infected cells revealed that a lot of viral antigens were accumulated in the cytoplasm as well as in the nucleus, and a number of budding virions were on the cell surfaces. Consistently, gel electrophoresis of infected cells demonstrated that the synthesis of virus proteins was abundant. These findings indicated that MOLT4 cells were permissive to influenza virus growth, with production of a relatively smaller number of infectious particles in terms of PFU. Production of interferon (IFN)-alpha and -gamma were not detected in this system by ELISA.

Animals↗
PubMed1993

[Blood purification after aorto-coronary bypass grafting for dialysis patients].

Four dialysis patients received aorto-coronary bypass grafting (CABG) at Fukuyama cardiovascular hospital from April 1989 to March 1992. We employed continuous ambulatory peritoneal dialysis (CAPD) in two cases, hemodialysis with extracorporeal ultrafiltration method (ECUM + HD) in one case and hemodiafiltration with continuous veno-venous hemofiltration (CVVHF + HDF) in one case for perioperative management. In each cases, intermittent HD was undergone during 4 days before operation. Intraoperatively, HD was used together with extracorporeal circulation. Blood pressure in the postoperative course changed more frequently in CAPD cases than ECUM + HD or CVVHF + HDF case. Especially, CVVHF + HDF stabilized the movement of circulation and kept balance of serum BUN, Cr after the operation (BUN; 27.2 +/- 6.3, Cr; 5.0 +/- 0.6). We concluded that CVVHF + HDF would be the most favorable method to maintain the fluid balance stably for the uremic patients after CABG.

Adult↗
PubMed1993

[A case report--successful surgical treatment of prosthetic aortic valve detachment with enlargement of sinuses of Valsalva caused by the recurrence of aortitis].

A successful operation on a 49-year-old female with aortitis syndrome associated with prosthetic aortic valve detachment was reported. Aortic valve replacement using SJM 25A had been performed for aortic regurgitation caused by aortitis. Though her C-reactive protein (CRP) was kept between (+/-) and (2+) with prednisolone administered, general fatigue suddenly appeared 4 years after the first operation. The blood sedimentation rate was 65 mm/30 min and CRP was (4+), and the echocardiography showed abnormal movement of the prosthetic valve with perivalvular leakage on admission. Aortography showed the valve detachment and abnormal movement due to enlargement of sinuses of Valsalva, one of which was transformed as a diverticulum and projected into Left ventricular cavity with moderate leakage. After the inflammation was well controlled, she was operated upon. Dilatation of sinuses, perforation of intima around the prosthetic valve were recognized as left ventricular-aortic discontinuity, but ascending aorta was not enlarged. So the prosthetic valve was suspended below coronary ostia with transmural mattress sutures from right atrium. Postoperative course was uneventful. The postoperative aortography revealed only trivial perivalvular leakage without abnormal movement of the valve. This was a rare case of the valve detachment in the aortitis patient.

Aortic Arch Syndromes↗
PubMed1992

In vitro formation of mineralized nodules by periodontal ligament cells from the rat.

The purposes of this study were to determine whether periodontal ligament (PDL) cells are capable of producing mineralized nodules in vitro and to analyze ultrastructural features of the nodules. Rat PDL cells were obtained from coagulum in the socket at 2 days after tooth extraction and cultured at confluence in standard medium containing Dulbecco's Modified Eagle's Medium supplemented with 10% FBS and antibiotics. To test mineralized nodule formation, cells were further cultured for an additional 3 weeks in the standard medium containing (1) ascorbic acid (50 micrograms/ml) and sodium beta-glycerophosphate (10 mM), (2) ascorbic acid, sodium beta-glycerophosphate, and dexamethasone (5 microM), or (3) ascorbic acid alone. Cells were then fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4, and prepared for light and electron microscopy. Three-dimensional nodules containing mineralized matrices were formed only when the cells were cultured in the presence of ascorbic acid and dexamethasone. They were composed of multilayered fibroblasts (up to 13 layers), and highly organized collagen fibrils with 64 nm cross-banding patterns between the cell layers. The fibroblasts in the nodules exhibited an elongated shape with a high degree of cytoplasmic polarity throughout the nodule, and have the morphological features of PDL fibroblasts as seen in vivo. Mineral deposition with needle-like crystals was initiated on collagen fibrils located in intercellular spaces of the upper cell layers and became increasingly heavier towards the bottom half of the nodules. X-ray microanalysis and electron diffraction analysis confirmed that mineral deposition contained calcium and phosphate in the form of immature hydroxyapatite.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

Possible involvement of Na(+)-H+ exchange in the early phase of reperfusion in myocardial stunning.

Calcium overload during reperfusion after prolonged ischemia has been associated with the Na(+)-Ca2+ exchange system. It has been proposed that the promotion of Na(+)-Ca2+ exchange at reperfusion may be mediated by Na(+)-H+ exchange. To evaluate whether this hypothesis is applicable for stunned myocardium, we examined the influence of temporary suppression of Na(+)-H+ and/or Na(+)-Ca2+ exchange during early reperfusion in isolated rat hearts. Myocardial stunning was produced by global ischemia for 15 min at 37 degrees C. The initial reperfusate was given during the subsequent 10 min after ischemia, and followed by reperfusion with normal Krebs-Henseleit buffer solution for 40 min. Hemodynamic indices, creatine kinase in coronary effluent, and myocardial water content were measured during reperfusion. The functional recovery of stunned myocardium was improved with higher extracellular Na+ concentration and/or lower Ca2+ concentration of the initial reperfusate. Aortic flow recovery of group II (135 mM Na(+)-0.5 mM Ca2+) was 77.0 +/- 3.4%, which was substantially greater (P < 0.05) than that of other groups: group I (control, 135 mM Na(+)-1.5 mM Ca2+), 68.2 +/- 2.4%; group III (25 mM Na(+)-0.5 mM Ca2+), 48.7 +/- 2.9%; group IV (25 mM Na(+)-1.5 mM Ca2+), 21.6 +/- 1.5%. Administration of amiloride, an inhibitor of Na(+)-H+ exchange, in the initial reperfusate ameliorates cardiac damage and improved aortic flow recovery in a dose-dependent manner (10(-6) M, 70.1 +/- 3.7%; 10(-5) M, 77.3 +/- 1.7%; 10(-4) M, 82.0 +/- 2.1% vs control 68.2 +/- 2.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1992

Inhibition of sarcoplasmic reticulum Ca(2+)-ATPase by 2,5-di(tert-butyl)-1,4-benzohydroquinone.

We characterized the interaction of 2,5-di(tert-butyl)-1,4-benzohydroquinone (tBuBHQ) with the sarcoplasmic reticulum (SR) Ca(2+)-ATPase from rabbit fast-twitch skeletal and canine cardiac muscles by examining the effect of this agent on the ATPase reaction. tBuBHQ at less than 10 microM inhibited ATP hydrolysis by both isoforms of Ca(2+)-ATPase by up to 80 and 90%, respectively. The half maximal inhibition of these enzymes was observed at about 1.5 microM tBuBHQ. Thus, this agent potently inhibits the fast-twitch skeletal and slow-twitch skeletal/cardiac isoforms of SR Ca(2+)-ATPase. tBuBHQ at 5-10 microM inhibited the rate of decomposition of the phosphoenzyme intermediate (EP), measured as a ratio between ATPase activity and the EP level in the steady state, by 35-40%. It also inhibited formation of EP by decreasing the rate of Ca2+ binding to the Ca(2+)-deficient, nonphosphorylated enzyme to about 1/8 of the control value. These results indicate that tBuBHQ has at least two sites of action in the reaction sequence for the SR Ca(2+)-ATPase.

Animals↗
PubMed1992

A sensitive enzymatic method (SK-013) for detection and quantification of specific periodontopathogens.

Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola have been found to predominate in periodontal pockets of patients with adult periodontitis. These microorganisms hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). In this study, we developed an enzymatic method, designated SK-013, to detect the existence of these microorganisms in subgingival plaque bacteria. This enzymatic method was based on the observation of the hydrolysis of N-carbobenzoxy-glycyl-glycyl-arginyl-3,5-dibromo-4-hydroxyaniline (N-CBz-Gly-Gly-Arg-DBHA) and made more sensitive by adding an enhancing system. The SK-013 was specifically positive for P. gingivalis, B. forsythus, T. denticola, and some strains of Capnocytophaga species, but was not specific for any of the other bacterial strains tested. This SK-013 system may be valuable for detection and quantification of periodontal disease-associated bacteria in subgingival plaque and thus for diagnosis of periodontal infections.

Bacteroides↗
PubMed1992

Mitogenic, chemotactic, and synthetic responses of rat periodontal ligament fibroblastic cells to polypeptide growth factors in vitro.

The mitogenic, chemotactic, and synthetic responses of rat periodontal ligament (PDL) fibroblastic cells to epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), recombinant human platelet-derived growth factor (rhPDGF)-AB, rhPDGF-BB, natural (n) PDGF-AB, and insulin-like growth factor-I (IGF-I) were examined in vitro using PDL cells obtained from the coagulum of healing tooth sockets. PDGFs and IGF-I have potent and comparable mitogenic effects on PDL fibroblastic cells. The maximum mitogenic effect of PDGFs was observed at the concentration of 10 ng/ml, whereas that of IGF-I was seen at concentrations higher than 100 ng/ml. In contrast, EGF induced moderate, and TGF-beta inhibitory mitogenic responses. The combination of rhPDGF-AB with either EGF or TGF-beta demonstrated comparable mitogenic potency, equivalent to the level of PDGF alone regardless of the mitogenic effect of other growth factors. The combination of rhPDGF-AB and IGF-I, however, showed a synergistic effect revealing the highest mitogenic effect among all individual growth factors as well as any combinations of the growth factors tested. Similarly, PDL fibroblastic cells demonstrated strong chemotactic responses to both IGF-I and PDGFs. The maximum effect was observed by IGF-I at concentrations higher than 10 ng/ml, followed by rhPDGF-BB at 0.1 ng/ml, rhPDGF-AB and nPDGF at concentrations ranging from 0.1 to 1 ng/ml. TGF-beta revealed no, and EGF slightly increased, chemotactic effects. IGF-I slightly enhanced the synthesis of total protein, whereas other factors had no significant effect. However, both rhPDGF-AB and TGF-beta stimulated collagen synthesis. On the other hand, IGF-I showed no effect on collagen synthesis, while EGF suppressed collagen synthesis. These findings suggest that rhPDGF-BB and IGF-I stimulate proliferation and chemotaxis of PDL fibroblastic cells. In addition, the combination of these growth factors further increases the mitogenic effect. rhPDGF-AB also stimulates collagen synthesis by PDL fibroblastic cells. Thus, rhPDGF-BB and IGF-I may have important roles in promotion of PDL healing, and consequently, may be useful for clinical application in periodontal regenerative procedures.

Animals↗
PubMed1992

Development of analytical methods to evaluate SFH.

For the determination of stroma content in SFH, two analytical methods were developed, the HPLC-UV for phospholipids and the enzyme immunoassay for blood group antigen. These analytical methods were applied to evaluate three representative SFH preparations. The 36,000 x g centrifugation method was shown to contain higher amount of stroma components. On the other hand, the BMM-40 nm and the ultrafiltration method with a 100 kd membrane was shown to remove more than 99.7% of phospholipids and almost all of blood group antigen from hemoglobin solutions. These results demonstrated that these analytical methods were very useful in evaluating any highly purified hemoglobin solutions.

ABO Blood-Group System↗
PubMed1992

Benastatins A and B, new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. I. Taxonomy, production, isolation, physico-chemical properties and biological activities.

Benastatins have been isolated as part of a program designed to find microorganism-produced inhibitors of glutathione S-transferase from Streptomyces sp. MI384-DF12. They were purified by chromatography of reversed-phase silica gel, silica gel and Capcell Pak C18 (HPLC) followed by solvent extraction and then isolated as yellow powders. Benastatins A and B have the molecular formulae, C30H28O7 and C30H30O7, respectively. They were competitive with 3,4-dichloronitrobenzene as the substrate, and the inhibition constants (Ki) of benastatins A and B were 5.0 x 10(-6) and 3.7 x 10(-6), respectively.

Animals↗
PubMed1991

Analysis of gastric carcinoma growth by endoscopic ultrasonography.

Endoscopic ultrasonography (EUS) was performed preoperatively in 82 patients with gastric carcinoma (40 with early and 42 advanced malignancy). Measurements of wall thickness were performed in each case and showed good correlation with histological findings. Wall thickening was found to consist of both tumorous and accompanying ulcerous tissue. Thus, increasing wall thickness, as demonstrated by EUS, may not necessarily mean progressive tumor growth. The EUS features of gastric carcinoma were analyzed and four distinct growth patterns found: predominantly intramural (IM) or intraluminal (IL) growth with preservation (Type 1) or destruction (Type 2) of the submucosal echo-rich layer. All early carcinomas displayed the IL-type growth pattern on EUS (98% IL1-type) and 81% of advanced tumors showed IM-type features. EUS was able to differentiate between early and advanced carcinoma in 98% of cases. The EUS pattern of submucosal destruction (type IM2 or IL2) corresponded to the expanding type tumor according to Ming's histopathological classification. On the other hand, 24 of 26 infiltrative tumors according to Ming were found on EUS to have an intramural growth pattern with preservation of the submucosa (type IM1). It is concluded that EUS is highly sensitive in predicting the tumor growth pattern in gastric carcinoma, providing important additional information to the currently used TNM staging system. Measurements of wall thickness are reliable but differentiation between tumorous growth and peritumorous changes is not possible.

Carcinoma↗