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Biomedical subjects

K Noguchi

Publications and source records attributed to K Noguchi.

At least 469 records · Page 26Linked to original sources
PubMed1985

Separation of ascorbic acid, dehydroascorbic acid, diketogulonic acid and glucose by isocratic elution from a column of a hydrophilic gel.

High-performance liquid chromatography on an Asahipak GS-320 hydrophilic gel column with tartrate buffer (0.015 M, pH 3.0) containing 2 mM ethylenediaminetetraacetate and 0.05% beta-thiodiglycol as the eluent allowed the separation of glucose, diketogulonic acid, dehydroascorbic acid and ascorbic acid within 30 min. Fluorimetric monitoring of these compounds in the eluate with benzamidine at alkaline pH and at 90 degrees C in the presence of potassium sulphite allowed the determination of nanogram amounts of ascorbic acid, dehydroascorbic acid and diketogulonic acid. This method was applied to the determination of ascorbic acid in fruit juice.

2,3-Diketogulonic Acid↗
PubMed1985

Effect of hypoxic cell radiosensitizers on glutathione level and related enzyme activities in isolated rat hepatocytes.

A comparative study of the effect of misonidazole and novel radiosensitizers on glutathione (GSH) levels and related enzyme activities in isolated rat hepatocytes was performed. Incubation of hepatocytes with 5 mM radiosensitizers led to a decrease in the intracellular GSH level. The most pronounced decrease in cellular GSH was evoked by 2,4-dinitroimidazole-1-ethanol (DNIE); after incubation for only 15 min, GSH was hardly detected. DNIE-mediated GSH loss was dependent upon its concentration. DNIE reacted with GSH nonenzymatically as well as with diethylmaleate, while misonidazole and 1-methyl-2-methyl-sulfinyl-5-methoxycarbonylimidazole (KIH-3) did not. Addition of partially purified glutathione S-transferase (GST) did not enhance DNIE-mediated GSH loss in a cell-free system. DNIE inhibited glutathione peroxidase (GSH-Px), GST, and glutathione reductase (GSSG-R) activities in hepatocytes, while misonidazole and KIH-3 did not. GSH-Px activity assayed with H2O2 as substrate was the most inhibited. Inhibition of GSH-Px activity assayed with cumene hydroperoxide as substrate and GST was less than that of GSH-Px assayed with H2O2 as substrate. GSSG-R activity was decreased by DNIE, but not significantly. Incubation of purified GSH-Px with DNIE resulted in a little change in the activity when assayed with H2O2 as substrate.

Animals↗
PubMed1985

Effect of intracoronary captopril on coronary blood flow and regional myocardial function in dogs.

To evaluate the cardiac effect of an inhibitor of angiotensin-converting enzyme, the effect of intracoronary (i.c.) captopril on coronary blood flow and regional myocardial function was examined in the anesthetized open-chest dog. Blood flow of the left circumflex coronary artery (LCX), left ventricular pressure (LVP), aortic pressure (AoP) and regional myocardial segment length were measured continuously. Captopril i.v. (0.3 mg/kg) produced an immediate reduction in AoP and an increase in percent shortening of myocardial segments followed by a decrease in coronary vascular resistance and increases in heart rate and LVdP/dt. Reductions in LCX flow induced by i.c. angiotensin were attenuated and i.c. bradykinin-induced increases in LCX flow were augmented after captopril. On the contrary, i.c. infusion of captopril (0.01 mg/min) into the LCX caused no change in hemodynamic variables and myocardial shortening although responses to angiotensin I and bradykinin were markedly modified. These results suggest that captopril may have no direct cardiac effect.

Acetylcholine↗
PubMed1985

Anti-O-phosphotyrosine antibodies in human sera.

Antibodies reactive with O-phosphotyrosine (PTYR) were detected in 60 out of 621 inpatients, with high frequencies in hematologic and lung malignancies, hepatic diseases, cerebrovascular diseases, and autoimmune diseases. Affinity-purified antibodies proved capable of recognizing PTYR-containing proteins in a human carcinoma cell line, A431, both by immunofluorescent staining and by immunoaffinity chromatography, but had no detectable affinity for phosphorylated serine or threonine, or for the nucleotides tested. In these respects, the antibodies observed in human sera were indistinguishable from anti-PTYR antibodies raised experimentally in rabbits or mice.

Adolescent↗
PubMed1985

A quantitative assay for mouse granulocyte (CFU-g) and macrophage (CFU-m) precursors using plasma clots.

Cytochemical procedures were used to identify and quantitate granulocyte and macrophage precursors from mouse bone marrow cells in plasma clot cultures. Excellent clonal morphology and cellular enzyme activity were obtained when using plasma clots as the support matrix and buffered formalin acetone as the fixative. For cytochemical identification, naphthol AS acetate esterase staining was used for macrophages and peroxidase for granulocytes. These enzyme properties were confirmed by inactivation studies with a variety of inhibitors, group specific chemical modifications, and pinocytotic affinity for horseradish peroxidase. When mouse bone marrow cells (3 X 10(4) cells/dish) were cultured in plasma clots with human placental or L-cell-conditioned medium, 70 to 110 colonies were produced. Both pure granulocyte (CFU-g) and pure macrophage colonies (CFU-m) were observed, but approximately 5% of the total colony number was composed of mixed granulocyte/macrophage colonies (CFU-gm). The number of plated cells correlated strongly with the colony number (0.990 less than r less than 0.999).

Animals↗
PubMed1985

Heat stable protein with anticoagulant and smooth muscle contractile actions isolated from Habu (Trimeresurus flavoviridis) venom.

The biological activity of a Habu (Trimeresurus flavoiridis) venom fraction with drug-metabolizing enzyme inhibitory action was studied. The venom fraction, which was isolated through Sephadex G-100 gel filtration and cation exchange chromatography on Amberlite CG50, caused an increase of vascular permeability and hemorrhage, but these actions were lost after heating at 70 degrees C for 5 min. The fraction showed anticoagulant activity on citrated blood, and this activity remained after heating of the venom. Guinea pig ileum was contracted by treatment with nonheated or heated venom fraction, and these contractions were inhibited with atropine and potentiated with physostigmine. These results suggest that the drug-metabolizing enzyme inhibitor isolated from Habu venom involves the heat stable component with anticoagulant activity and smooth muscle contractile action.

Animals↗
PubMed1985

Immunofluorescent staining of human leukemic cells with monoclonal antibody to phosphotyrosine.

Peripheral blood cells and bone marrow cells from patients with various types of leukemia, but not those from healthy persons, were brightly immunofluorescent (IF) after staining with monoclonal antibody reactive to O-phosphotyrosine. All the IF-positive cells observed in peripheral blood were judged to be leukemic in morphology, and the IF-positive cells comprised 40-90% of total leukemic cells present in blood. Similar bright fluorescence was observed in the K562 human leukemic cell line. The results raise the possibility that leukemic cells can be distinguished from normal hematologic cells by their increased contents of phosphorylated tyrosine residues.

Antibodies, Monoclonal↗
PubMed1985

[Effect of anticancer agents on rat prostate. Evaluation of organ weight, histological finding and 5 alpha-reductase activities].

To evaluate the effect of anticancer chemotherapeutic antigens on rat prostate, ten kinds of anticancer agents corresponding to the dose generally used for humans were intraperitoneally injected to 63-day-old Wistar rats. The anticancer agents were administered as follows: Cyclophosphamide (CPM) was used at the dose of 8 mg/kg for 7 days. Methotrexate (MTX), actinomycin-D (ACD) and cis-platinum (CDDP), 163 micrograms/kg, 8 micrograms/kg and 833 micrograms/kg for 5 days, respectively. Nitrogen mustard (NM), bleomycin (BLM), peplomycin (PLM), adriamycin (ADM), vincristine (VCR), and vinblastine (VBL), 500 micrograms/kg, 250 micrograms/kg, 170 micrograms/kg, 2.5 mg/kg, 33 micrograms/kg and 83 micrograms/kg, twice in a week, respectively. The rats were killed on the fifth day after completion of the schedule. Then, the weight of the body, the prostate, the epididymis and the adrenal gland were measured. In addition, 5 alpha-reductase activities and histological findings in the prostate were examined. For determination of 5 alpha-reductase activities, cell-free homogenate obtained from the rat ventral prostate was incubated with C14-testosterone at 37 degrees C for 30 minutes in an atmosphere of 95% of O2 and 5% of CO2. Subsequently, the metabolites from testosterone were separated and purified with thin layer chromatography using the solvent system with benzene acetone, 4:1 (v/v). 5 alpha-Reductase activity was determined with the sum of dihydrotestosterone (DHT) and androstanediol converted from testosterone and indicated as pmol product/mg protein. The 5 alpha-reductase activity was employed as a biological marker for the degree of androgenic dependency in the prostate. The results were summarized as follows. CDDP significantly reduced the weight of the body (p less than 0.001, n = 7), but not the activity of 5 alpha-reductase. NM and VBL had a specific action to reduce the weight of the prostate (p less than 0.01, n = 8) without causing loss of body weight. NM and VBL showed no influence on 5 alpha-reductase activities. The activity of 5 alpha-reductase was markedly damaged by BLM (p less than 0.05, n = 6) and PLM (p less than 0.05, n = 5). However no significant reduction was recognized in the weight of the body and the prostate. CPM, MTX, ACD, ADM and VCR were ineffectual on the body and the prostate weight and 5 alpha-reductase activities. In the histological examination, atrophy and degeneration of the glandular epithelium were revealed in the prostate treated with NM, VBL and CDDP.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Effects of nipradilol (K-351) on cardiac function in anesthetized open-chest dogs.

Effects of nipradilol (K-351) on cardiac performance and myocardial oxygen consumption were investigated in anesthetized open-chest dogs. Nipradilol 0.1 mg/kg i.v. induced falls in systolic and diastolic aortic blood pressure and left ventricular pressure, and decreases in cardiac output, coronary sinus outflow, left ventricular dP/dt and heart rate. Stroke volume was transiently increased and left ventricular stroke work index was significantly decreased, while left ventricular mechanical efficiency was not significantly changed. Myocardial oxygen consumption was significantly decreased. Total peripheral vascular resistance and coronary vascular resistance were persistently increased. Left ventricular enddiastolic pressure was not significantly changed. These results suggest that nipradilol has a possible antianginal property through a decrease in myocardial oxygen consumption due to a fall in aortic blood pressure and a decrease in heart rate.

Adrenergic alpha-Antagonists↗
PubMed1985

Plasma cell leukemia accompanied by polyclonal gammopathy and congenital tumor in the atrioventricular node.

A 32-year-old man with plasma cell leukemia and congenital tumor of the atrioventricular node is described. Although M protein could not be detected by immunoelectrophoresis, the examination of bone marrow atypical plasma cells with immunofluorescent and immunoperoxidase showed that most of these plasma cells produced IgG or IgA. Also some plasma cells possessed concomitantly both IgG and IgA. An electrocardiogram revealed complete atrioventricular block. The patient died of aspergillosis and bleeding in the lung. Postmortem examination revealed the infiltration of atypical plasma cells in the bone marrow, spleen, liver and lungs, and infiltration of mesothelial tumor cells in the atrioventricular node.

Adult↗
PubMed1985

Human bone marrow fibroblastic cells can inhibit clonogenic growth of K562 cells.

The influence of human bone marrow fibroblastic cells (FC) on the proliferation of K562 leukemic colony-forming cells (LCF-C) was studied. FC derived from normal subjects and patients with acute leukemia were used. The growth of LCF-C was evaluated by colony-forming efficiency in soft agar. Inhibition of leukemic colony formation was produced by FC from normal subjects and patients with acute leukemia. While the degree of inhibition by FC from patients with acute lymphocytic leukemia was almost the same as that by those from the normal subjects, that by FC from patients with acute nonlymphocytic leukemia was lower than that by those from normal individuals. Both conditioned media obtained from FC and contact of their FC with LCF-C in dishes for four hr inhibited leukemic colony formation. These data show that leukemic stem cells are inhibited by bone marrow FC through cell-to-cell contact or humoral factors derived from FC.

Bone Marrow↗