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Biomedical subjects

N Yoshida

Publications and source records attributed to N Yoshida.

At least 325 records · Page 18Linked to original sources
PubMed1995

Purification and properties of fructosyl lysine oxidase from Fusarium oxysporum S-1F4.

Fructosyl lysine oxidase (FLOD) was examined for its use in the enzymatic measurement of the level of glycated albumin in blood serum. To isolate microorganisms having such an enzyme activity, we used N epsilon-fructosyl N alpha-Z-lysine (epsilon-FL) as a sole nitrogen source in the enrichment culture medium. The isolated fungus, strain S-1F4, showed a high FLOD activity in the cell-free extract and was identified as Fusarium oxysporum. FLOD was purified to an apparent homogeneity on SDS-PAGE. The molecular mass of the subunit was 50 kDa on SDS-PAGE and seemed to exist in a monomeric form. The enzyme had an absorption spectrum characteristic of a flavoprotein and the flavin was found to be covalently bound to the enzyme. The enzyme acted against N epsilon-fructosyl N alpha-Z-lysine and N alpha-fructosyl N epsilon-Z-lysine and showed specificity for fructosyl lysine residues.

Amino Acid Oxidoreductases↗
PubMed1995

Primary malignant lymphoma of the liver associated with cirrhosis induced by hepatitis C viral infection.

We present a case of primary malignant lymphoma of the liver of B cell origin with cirrhosis induced by hepatitis C viral infection. A 75-year-old Japanese woman with chronic liver dysfunction was admitted for hepatic tumors. The tumors were hypoechoic on ultrasonography and hypodense on computed tomography. Antibody to hepatitis C virus was positive. Ultrasonically guided biopsy was performed, and we diagnosed hepatic lymphoma with cirrhosis induced by hepatitis C virus clinically and immunohistochemically. This case may be the first report of the association of these two diseases, and may provide additional evidence of a predisposition to malignancy in cirrhosis.

Aged↗
PubMed1995

Simultaneous intraperitoneal administration of OK-432 and serum enhances superoxide generation from migrated polymorphonuclear leukocytes, with special emphasis on the role of complements.

Superoxide and its derived active oxygen species are responsible for the polymorphonuclear leukocyte (PMN)-mediated tumoricidal activity which is typically shown in the intraperitoneal administration of OK-432, a biological response modifier, for cancer ascites. We examined the effects of intraperitoneal administration of OK-432 with or without syngeneic serum on superoxide generation from PMNs which migrated in the peritoneal cavity using the new method of Cypridina luciferin analog-dependent chemiluminescence for the detection of superoxide. PMNs harvested from rat peritoneal cavity 6 h after the intraperitoneal administration of OK-432 (0.25KE/kg, or 2.5KE/kg) generated larger amounts of superoxide than those harvested after intraperitoneal injection of oyster glycogen (75mg/kg) when stimulated by opsonized zymosan or phorbol myristate acetate. Simultaneous intraperitoneal administration of OK-432 and syngeneic serum induced a greater increase in PMN superoxide generation than OK-432 alone, which was reversed by a complement activation inhibitor (MX-1). Simultaneous injection of OK-432 and heat-inactivated syngeneic serum did not exhibit a significant increase in PMN superoxide generation as compared with OK-432 alone. These results provide pharmacological evidence to the satisfactory therapeutic effects of the intraperitoneal administration of OK-432 with or without serum for patients with cancer ascites, and indicate that complements, in particular C5a, are involved in this enhanced PMN-derived superoxide generation induced by the simultaneous injection of OK-432 and serum.

Animals↗
PubMed1995

Molecular weight-dependent lymphatic transfer of fluorescein isothiocyanate-labeled dextrans after intrapulmonary administration and effects of various absorption enhancers on the lymphatic transfer of drugs in rats.

We have developed a new method to evaluate the transfer of macromolecular drugs to intrapulmonary lymph nodes in rats after intrapulmonary administration. By using this method, we observed that the transfer of fluorescein isothiocyanate dextrans (FDs) to the intrapulmonary lymph nodes was markedly higher than that to iliac lymph node, a non-intrapulmonary lymph node. The transfer of FDs to the intrapulmonary lymph nodes increased with increasing their molecular weights and the threshold for a high lymph node-to-plasma level ratio (CLN/CP) was between 10 and 20 kDa. The effects of absorption enhancers on the transfer of FDs to intrapulmonary lymph nodes were also examined in rats. Absorption enhancers used in this study were EDTA, sodium glycocholate (Na-GC), mixed micelles (MM), N-lauryl-beta-D-maltopyranoside (LM), sodium caprate (Na-Cap). The transfer of FD-20, FD-40 and FD-70 to intrapulmonary lymph nodes after intrapulmonary administration increased in the presence of LM. In particular, the lymphatic transfer of FD-40 was remarkably increased in the presence of LM. Similarly, Na-GC and MM improved the transfer of FD-40 to intrapulmonary lymph nodes. These results suggest that absorption enhancers such as LM, Na-GC and MM are effective for improving the transfer of macromolecular drugs to intrapulmonary lymph nodes.

Absorption↗
PubMed1995

[Subgingival distribution of periodontopathic bacteria in periodontic patients and susceptibility of these bacteria to minocycline-HCl].

The present study was carried out to examine the distribution of six periodontopathic bacteria in deep periodontal pockets and to reconfirm the effect of Periocline on these periodontopathic bacteria. Samples from sixty-two periodontal pockets were collected at pocket depths of over 4 mm in twenty-one periodontitis patients aged 43 to 75 years. After sampling, Periocline was applied topically to the selected pockets once a week for four weeks and reexamined. The detected rates of the periodontopathic bacteria were Capnocytophaga sputigena (37.1%), Prevotella intermedia (22.6%), Porphyromonas gingivalis (22.6%), Fusobacterium nucleatum (20.1%), Actinobacillus actinomycetemcomitans (9.7%) and Eikenella corrodens (4.8%). The distribution of the bacteria was compound because two or three bacterial species were found to coexist. In view of the MIC of minocycline-HCI for these bacteria, increase of most of the measured bacteria was suppressed by the concentration of drugs, including Periocline. However, clinical strains of P. i. were considered to have low susceptibility to minocycline-HCl. In view of the effect of topical application of drugs, no significant differences were found. From these results, it was suggested that Periocline contained effective concentration of minocycline-HCl.

Adult↗
PubMed1995

[Induction and maintenance therapy in all-trans retinoic acid with relapsed acute promyelocytic leukemia].

We reported a 17-year-old girl with relapsed acute promyelocytic leukemia (APL) who achieved complete remission and has been received maintenance therapy with all-trans retinoic acid (ATRA). The patient was diagnosed as APL in 1986. The ANLL 861 protocol of the Children's Cancer and Leukemia Study Group induced complete remission, and the chemotherapy was discontinued in 1989. However, she suffered a relapse with APL in 1991 and begun receiving ATRA (30 mg/m2/day) therapy because of disseminated intravascular coagulation. Bleeding tendency was discontinued by day 5. During the treatment, the white blood cell count increased markedly to 35,510 per microliters on 15th day, however she achieved complete remission morphologically on day 18. After informed consent was obtained from the family, she has been given ATRA orally for more than three years at the time of this report. The pharmacokinetics examination (ATRA 20 mg/m2 single per os) was performed 12 and 22 months after the induction therapy. The each peak plasma level of ATRA was 89 and 149 ng/ml. The concentration of ATRA has yet reached a level despite the continuous ATRA therapy. We considered that it may be useful to monitor plasma levels of ATRA during the treatment.

Adolescent↗
PubMed1995

Properties of alkaline phosphatase in the gingival crevicular fluid.

The isoenzymic properties of the alkaline phosphatase (ALP) of the gingival crevicular fluid (GCF) were investigated and compared with those in other cells, such as human polymorphonuclear leukocytes (PMNs), and human periodontal ligament cells (PDLs), and with those of three species of periodontopathic bacteria: Porphyromonas gingivalis 381 (P. gingivalis), Prevotella intermedia ATCC25611 (P. intermedia), and Capnocytophaga sputigena ATCC33123 (C. sputigena). The biochemical properties of the isoenzymes were analyzed by the following methods: enzyme assays, inhibition pattern using three chemical inhibitors, 4 to 20% gradient polyacrylamide gel electrophoresis, thermostability, immunological specificity, and phosphatidylinositol-specific phospholipase C (PI-PLC) treatment. The inhibition experiment showed that ALP of the PMNs and PDLs possessed almost the same enzymatic properties of tissue-nonspecific ALP (bone/liver/kidney; TNSALP), and the ALP of the three species of periodontopathic bacteria possessed specific properties that were different from those of TNSALP, intestinal, or placental ALP. The ALP of the GCF was only slightly susceptible to levamisole (1 mM), L-phenylalanine (20 mM), and SDS (1%). An electrophoresis thermostability test demonstrated that the enzyme activity of the GCF was separated into one or two bands. The main heat-labile slow band contained the phosphatidylinositol (PI)-moiety-anchored ALP and possessed immunological specificity against anti-bone type ALP. The minor fast band was heat stable and showed mobility similar to that in P. gingivalis. These results indicated that the ALP of the GCF consisted of several ALP isoenzyme types whose possible origins are considered to be derived from phosphatidylinositol (PI) anchored ALP and periodontopathic bacterial ALP.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Relations between chest CT and pathologic findings in pulmonary infarction associated with lung cancer].

Chest radiographic (mainly CT), and pathological findings in pulmonary infarction associated with lung cancer were studied to obtain information useful for the interpretation of CT findings, and to help determine the cause of infarction. Sixteen cases of lung infarction were chosen from among 518 cases of lung cancer. All patients were operated on between January 1980 and December 1990. Sixteen surgical cases and one autopsy case all with evidence of lung cancer and infarction were chosen. There were 13 men and 4 women with a mean age of 56 years. Adenocarcinoma was found in 8 cases, squamous cell carcinoma in 6, adenosquamous carcinoma in 2, and small cell carcinoma in 1. Chest radiographs and CT revealed infarction shadows in 8 of the 16 cases. Typical CT findings for pulmonary infarction were: shadows located in the same lobe and periphery as the cancer; ill-defined, 10-25 mm nodular shadows; and lesions located both in the subpleural zone and apart from the pleura. Lesion counts in each area were about the same. Observation of one patient for 2 months revealed a decrease in the size of the nodular shadows and clarification of their margins. In most cases, centrally extended cancer resulted in vascular stenosis and infarction.

Adenocarcinoma↗
PubMed1995

Role of neutrophil-endothelial cell interactions in gastric mucosal injury induced by aspirin.

Recent studies have indicated that aspirin promotes neutrophil adherence to endothelium via CD11/CD18-dependent interactions with intercellular adhesion molecule 1, which subsequently leads to neutrophil-mediated cell injury. The objectives of the present study were to determine the role of neutrophil-endothelial cell interactions and lipid peroxidation in aspirin-induced gastric mucosal injury in rats. Oral administration of aspirin and HCl produced hemorrhagic erosions in the stomach of rats. Myeloperoxidase (MPO) activity in the gastric mucosa, an index of neutrophil infiltration, significantly increased 3 h after aspirin administration. The concentration of thiobarbituric acid-reactive substances (TBA-RS) in the gastric mucosa, an index of lipid peroxidation, increased slightly 3 h after aspirin administration. In rats treated with antineutrophil serum, both the total area of gastric erosions and MPO activity were significantly reduced. In addition, pretreatment with anti-CD18 monoclonal antibodies significantly attenuated gastric mucosal damage and inhibited the increases in both MPO activity and TBA-RS in the gastric mucosa after aspirin administration. These observations suggest that CD18-dependent neutrophil-endothelial cell interactions and lipid peroxidation play an important role in the pathogenesis of gastric mucosal lesions induced by aspirin.

Animals↗
PubMed1995

Effects of oxygen radical scavengers on the quality of gastric ulcer healing in rats.

Oxygen free radicals have been implicated in the pathogenesis of gastrointestinal mucosal injury. However, their effect on the quality of experimental gastric ulcer healing has not been investigated previously. Gastric ulcers were produced on the anterior wall of the stomach of rats by submucosal injection of 20% acetic acid. To investigate the role of oxygen radicals, rats with gastric ulcers were treated with scavengers for 6 weeks. Rats received either a daily dose of 20,000 U/kg of recombinant human Cu,Zn-SOD, a 1% solution of DMSO administered orally ad libitum, or 50 mg/kg/day of allopurinol administered orally. The quality of ulcer healing was evaluated by histologic and biochemical parameters: ulcer area, lipid peroxide levels, abnormality of regenerated mucosa, angiogenesis, and fibrosis as assessed by Azan staining, mucin content as assessed by the PAS-positive area, and polymorphonuclear leukocyte (PMN) infiltration. The treatments with SOD, DMSO, or allopurinol did not affect the ulcer area or lipid peroxide levels in the gastric mucosa, and SOD did not affect the histologic abnormality score, PMN infiltration in regenerated mucosa, the collagen fiber proliferation index, or the PAS-positive mucous score. DMSO and allopurinol significantly increased the collagen fiber proliferation index and the PAS-positive mucous score compared with controls. These results indicate that scavenging hydroxyl radicals or inhibiting xanthine oxidase enhances the quality but not the speed of gastric ulcer healing.

Animals↗
PubMed1994

Binding properties of the coagulation factor IX/factor X-binding protein isolated from the venom of Trimeresurus flavoviridis.

The binding properties of the coagulation factor IX/factor X-binding anticoagulant protein (IX/X-bp) isolated from the venom of Trimeresurus flavoviridis (habu snake) were investigated with an enzyme-linked immunosorbent assay. The half-maximal binding and maximal binding of IX/X-bp to both factors IX and X were observed at concentrations of Ca2+ ions of 0.4 mM and 1 mM, respectively. Concentration of IX/X-bp at half-maximal binding to solid-phase bovine factor IX and solid-phase bovine factor X were 0.4 +/- 0.1 nM and 1.1 +/- 0.4 nM, respectively, in the presence of 1 mM Ca2+ ions. The kinetics of binding activity of IX/X-bp to bovine factors IXa and Xa and to human factors IX and X resembled those of the binding to bovine factors IX and X. IX/X-bp did not bind to solid-phase coagulation factors other than factor IX/IXa and factor X/Xa, for example, prothrombin, factor VII, protein C, and protein Z, under the conditions of the experiment. To localize the binding sites of IX/X-bp on the coagulation factors, the ability of IX/X-bp to bind to various fragments derived from factors IX and X was examined. The binding of IX/X-bp to solid-phase factor IX was inhibited by a peptide containing the 4-carboxyglutamic acid (Gla) domain derived from factor IXa beta' (residues 1-42) in the liquid phase, but the binding was not inhibited by Gla-domainless factor IXa beta'. Half-maximal binding of IX/X-bp to solid-phase Gla-domain peptide of factor IX occurred at 9.2 +/- 1.9 nM. Factor X was partially reduced and the S-carboxymethylated light and heavy chains of factor X were prepared. IX/X-bp bound to the S-carboxymethylated light chain of factor X but not to the heavy chain. The binding of IX/X-bp to solid-phase factor X was inhibited by the Gla-domain peptide of factor X (residues 1-44) but not by Gla-domainless factor X. IX/X-bp bound to PCGFX, a recombinant human protein C whose Gla-domain region (residues 1-43) had been replaced by residues 1-43 of human factor X. The affinity of binding was about one tenth of that to intact human factor X. IX/X-bp was unable to bind at all to human protein C. These data indicate that IX/X-bp is a protein that binds to the Gla-domain regions of factors IX and X in the presence of Ca2+ ions.

Animals↗
PubMed1994

Biological activities of 24-fluoro-1 alpha,25-dihydroxyvitamin D-2 and its 24-epimer.

Biological activities of two epimeric 24-fluorinated vitamin D-2 analogs, 24-fluoro-1 alpha,25-dihydroxyvitamin D-2 [24-F-1,25-(OH)2D2] and its 24-epimer [24-epi-24-F-1,25-(OH)2D2], were studied and compared with 1 alpha,25-dihydroxyvitamin D-3 [1,25-(OH)2D3] and 1 alpha,25-dihydroxyvitamin D-2 [1,25-(OH)2D2]. 24-F-1,25-(OH)2D2 was nearly as active as 1,25-(OH)2D3 and 1,25-(OH)2D2 both in regulating calcium metabolism in vivo including bone mineral mobilization and intestinal calcium transport and in inducing differentiation of HL-60 cells. While 24-epi-24-F-1,25-(OH)2D2 showed distinct properties in these two types of the actions. Though the 24-epimer was nearly as potent as 1,25-(OH)2D3 in inducing differentiation of HL-60 cells, it showed little activity in regulating calcium metabolism in vivo. The fluorine atom introduced at the 24-position of either 1,25-(OH)2D2 or its 24-epimer had no potentiating effect. This is in sharp contrast with the cases of 24- and 26,27-multifluorinated analogs of active vitamin D-3.

Animals↗
PubMed1994

The role of inositol trisphosphate on ACh-induced outward currents in bullfrog saccular hair cells.

Acetylcholine (ACh) is considered as the most likely candidate for a neurotransmitter of the efferent synapse onto hair cell. In this paper, the nature of this cholinergic receptor mechanism on dissociated bullfrog saccular hair cell was examined by using whole cell recording and Ca2+ sensitive fluorophotometric technique. Both the ACh-induced current and the increase of [Ca2+]i were observed in an oscillatory manner, and were the largest around the basal part of the cell where the efferent synapse is thought to make a contact with the membrane. The reversal potential of ACh-induced current indicated that ACh activated a K+ conductance. The ACh-induced current was reversibly blocked by atropine, d-tubocurarine (dTC), apamin, tetraethylammonium (TEA) and quinine. Neither muscarine nor nicotine mimicked the ACh-induced current. When GTP gamma S was injected into a hair cell, the first ACh application induced an outward current of transient kinetics, but in subsequent trials ACh-induced current lost its decay phase. Intracellularly injected D-myo-inositol 1,4,5-trisphosphate (InsP3) generated outward currents. Intracellularly injected heparin suppressed ACh-induced currents, and lithium (Li+) increased ACh-induced currents. These results indicate that ACh activates a receptor coupled with a guanine nucleotide binding protein (G-protein) which triggers metabolic cascades of InsP3 and Ca2+ leading to the activation of the Ca(2+)-activated K+ channel.

Acetylcholine↗
PubMed1994

Inhibition of matrix metalloproteinases by peptidyl hydroxamic acids.

Synthetic inhibitors of interstitial collagenase, tri- and tetrapeptidyl hydroxamic acids, have been developed and tested for their inhibitory activities against human matrix metalloproteinases. A water soluble inhibitor, p-NH2-Bz-Gly-Pro-D-Leu-D-Ala-NHOH (FN-439) inhibited interstitial and granulocyte collagenases, granulocyte gelatinase and skin fibroblast stromelysin with IC50 of 1 x 10(-6) M, 3.0 x 10(-5) M and 1.5 x 10(-4), respectively, but not thermolysin and serine proteinases. FN-439 was found to retain its inhibitory activity against matrix metalloproteinases even after prolonged incubation with pronase or human granulocyte elastase, indicating a favorite candidate of the inhibitor to modulate metalloproteinase activities in vivo.

Amino Acid Sequence↗
PubMed1994

Cloning and characterization of a gene for the stage-specific 82-kDa surface antigen of metacyclic trypomastigotes of Trypanosoma cruzi.

We have cloned and sequenced a cDNA clone coding for a metacyclic trypomastigote-specific surface glycoprotein with a molecular mass of 82 kDa (MTS-gp82). By immunoblotting and immunoprecipitation, antibodies against the recombinant protein recognized an 82-kDa protein of metacyclic trypomastigotes, without any detectable reaction towards amastigotes, epimastigotes or tissue culture-derived trypomastigotes. The insert of the MTS-gp82 cDNA clone strongly hybridized with a single 2.2-kb metacyclic trypomastigote mRNA, suggesting that the steady-state levels of mRNAs for MTS-gp82 are developmentally regulated. MTS-gp82 is encoded by a multigene family whose members are distributed in several chromosomes. Sequence analysis revealed 40-56% identity at amino acid level between MTS-gp82 and members of Trypanosoma cruzi gp85/sialidase family (TSA-1, Tt34c1, SA85-1.1). MTS-gp82 showed several amino acid motifs that are characteristic of gp85/sialidase family, such as the Asp box (SxDxGxTW), the subterminal (VTVxNVFLYNR) motif and the putative GPI-anchor sequence. On the basis of its structural features, the MTS-gp82 gene could be included in the T. cruzi gp85/sialidase family, but constituting a distinct group which is preferentially expressed in metacyclic trypomastigotes.

Amino Acid Sequence↗
PubMed1994

The immune responses in CD40-deficient mice: impaired immunoglobulin class switching and germinal center formation.

An engagement of CD40 with CD40 ligand (CD40L) expressed on activated T cells is known to provide an essential costimulatory signal to B cells in vitro. To investigate the role of CD40 in in vivo immune responses, CD40-deficient mice were generated by gene targeting. The significant reduction of CD23 expression on mature B cells and relatively decreased number of IgM bright and IgD dull B cells were observed in the mutant mice. The mutant mice mounted IgM responses but no IgG, IgA, and IgE responses to thymus-dependent (TD) antigens. However, IgG as well as IgM responses to thymus-independent (TI) antigens were normal. Furthermore, the germinal center formation was defective in the mutant mice. These results suggest that CD40 is essential for T cell-dependent immunoglobulin class switching and germinal center formation, but not for in vivo T cell-dependent IgM responses and T cell-independent antibody responses.

Animals↗
PubMed1994

Interleukin-2 expanded tumor-infiltrating lymphocytes and their response to preoperative alpha-interferon in patients with renal cell carcinoma.

To determine whether interferon-alpha could augment antitumorigenic effect of the tumor-infiltrating lymphocytes expanded with interleukin-2, we evaluated the properties of interleukin-2 expanded tumor-infiltrating lymphocytes in 24 patients with renal cell carcinoma with or without treatment with interferon-alpha. Tumor-infiltrating lymphocytes containing tumor cells were separated from nephrectomy specimens by enzymatic digestion and Percoll gradient centrifugation, and were cultured in the serum-free medium containing interleukin-2. The number of lymphocytes increased by 10 to 1,000-fold by day 28 of culture. There was no difference in the proliferation of tumor-infiltrating lymphocytes between interferon-alpha treated patients and controls. On day 14 tumor-infiltrating lymphocytes in the treated patients contained significantly more activated cells (HLA-DR+) and suppressor T cells (CD8+11+) than those in the controls. No significant difference was noted, however, in the cytotoxicity of tumor-infiltrating lymphocytes against autologous and allogenic renal cell carcinoma, K-562 or Daudi cells between the experimental and control groups on day 14 or 28. No specific effects on the major histocompatibility antigens, such as modulation of the expression attributable to the preoperative treatment with interferon-alpha, were observed on renal cell carcinoma tissue when determined by immunohistochemical staining. These findings suggest that interferon-alpha does not consistently produce a beneficial effect on interleukin-2 expanded tumor-infiltrating lymphocytes in patients with renal cell carcinoma.

Adult↗