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Biomedical subjects

N Ikeda

Publications and source records attributed to N Ikeda.

At least 361 records · Page 20Linked to original sources
PubMed1984

Purification and characterization of the multiple forms of 3 alpha-hydroxysteroid dehydrogenase in rat liver cytosol.

The presence of multiple forms of 3 alpha-hydroxysteroid dehydrogenase in the cytosol of male rat livers was demonstrated. The enzyme activity was separated into two fractions (F3 and F4) by DEAE-cellulose chromatography, and further fractionation of F3 into four (I-IV) and F4 into three (I-III) fractions was achieved by subsequent CM-Sephadex chromatography. Six forms (F3-II-IV and F4-I-III) were further purified by chromatofocusing and Red-Sepharose 4B chromatography. Two (F4-II and III) of the isolated enzymes were homogeneous, based on polyacrylamide gel electrophoresis. No shift of pI values was observed, when isoelectric focusing was performed with the F4 enzyme species in the presence of NAD(P)+ or NAD(P)H. All six enzyme species migrated closely with each other on dodecyl sulfate-polyacrylamide gel electrophoresis, from which the molecular masses were estimated to be 32 500 Da. Gel filtration gave similar values for the F4 enzyme species, indicating that each enzyme is a monomeric peptide. All enzyme species were able to catalyse the dehydrogenation of 3 alpha-hydroxysteroids (C19 to C26), and not C27 compound having a 1,5-dimethylhexyl side chain. The catalytic properties with steroids were very similar for five of the enzyme species, but F3-IV especially preferred androsterone. When male rat livers were used for isolation, the enzyme activity ratio of F3 to F4 for androsterone was about 1 to 8, whereas the ratio was about 1 to 20 for female rat livers. Considering the biosynthetic pathway of bile acids, the enzymes isolated here might play a specific role in the conversion of a 3 beta-hydroxy group to a 3 alpha-hydroxy group via a 3-oxo group of an intermediate in the synthesis of bile acids.

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

[Studies on tobramycin by the intravenous drip infusion method].

Fundamental and clinical efficacy evaluation has been made in the study on the therapy with intravenous drip infusion of tobramycin (TOB) which is one of the aminoglycoside antibiotics and which has been recently approved of intravenous administration. The fundamental evaluations were made with intravenous drip infusion of 60 mg of TOB for 1 hour and that of 120 mg of TOB for 2 hours to 4 healthy adult volunteers on crossover method. Follow-up determinations were made for comparison on its concentrations in blood and urine samples which were collected both at intervals thereafter, using 2 assay methods of the bioassay and the EMIT methods. The maximum blood level of TOB based on the intravenous drip infusion of 60 mg for 1 hour was 5.9 micrograms/ml and 4.6 micrograms/ml by the bioassay and the EMIT methods at the end of intravenous drip infusion, respectively, and 0.3 micrograms/ml and 0.4 micrograms/ml, respectively, at 6 hours after the drip infusion. The T 1/2 value was 1.81 hours with bioassay and 2.41 hours with the EMIT method. The maximum blood level of TOB through drip infusion method of 120 mg of TOB for 2 hours was 7.5 micrograms/ml by bioassay and 5.8 micrograms/ml by EMIT method. The T 1/2 value was 1.87 hours and 1.99 hours, respectively. The recovery rate of TOB from urine until 24 hours after the administration was 83.0% and 94.4% with the doses of 60 mg and 120 mg, respectively, which were determined only with the bioassay. The correlation coefficient between the agar well method and the EMIT method was 0.963 and 0.972 in the groups of intravenous drip infusion of 60 mg for 1 hour and 120 mg for 2 hours, respectively, showing proximity to each other. TOB was kept administered with a daily dose of 120 mg at a time to 11 cases and at 2 times to 1 case with chronic complicated infections of urinary tracts (comprising 9 cases with chronic complicated cystitis, 2 with chronic complicated pyelonephritis, and 1 with acute epididymitis). Of the 12 patients, 8 could meet the criteria for evaluation of drug efficacy and 6 of them proved to be effective, while 2 were ineffective. The efficacy rate was so high as 75%. The rate of disappearance of bacteria was 80.0%, which was very high. No side effect was specifically found out, except 1 case showing slight rise in S-GOT.

Adult↗
PubMed1984

Effects of a "single shot" of urokinase on fibrinolytic activities in patients with IgA nephropathy.

A study on the clinical effects of urokinase in patients with IgA nephropathy is described. Three different methods of administration, including single, continuous, and mixed administration, were employed in this study. Measurements of plasminogen, plasmin and alpha 2-plasmin inhibitor levels in plasma were performed during the course of urokinase administration in patients with IgA nephropathy and chronic proliferative glomerulonephritis. Measurements of alpha 1-anti-trypsin and alpha 2-macroglobulin levels were also performed in these patients. Urinalysis was performed both before and after administration of urokinase. It was demonstrated that a single shot of urokinase induced a significant fibrinolytic activity in patients with IgA nephropathy, and that a single shot of urokinase was effective in improving proteinuria and/or hematuria in patients with IgA nephropathy. It is concluded that a single shot of urokinase may be useful for treatment of patients with IgA nephropathy.

Fibrinolysis↗
PubMed1984

Detection of polymeric IgA in sera from patients with IgA nephropathy determined by thin-layer gel filtration.

Polymeric IgA in sera was determined by thin-layer gel filtration in patients with IgA nephropathy, other glomerular diseases, IgA myeloma and healthy adults to determine whether serum IgA is composed of a monomeric and/or larger polymers in these patients. The levels of IgA in sera were also quantitated by laser nephelometer in these patients. Eleven patients with IgA nephropathy (Berger's disease), six patients with other glomerular diseases, three patients with IgA myeloma and four healthy adults were examined. It was shown that the polymerized IgA in sera from patients with IgA nephropathy was significantly higher than that in sera from patients with other glomerular diseases and healthy adults. Levels of IgA in sera from patients with IgA nephropathy are significantly higher than that in sera from patients with other glomerular diseases and healthy adults. These findings suggest that an increase in serum IgA from patients with IgA nephropathy may be mainly due to an increase in polymers rather than the monomer of IgA.

Chromatography, Gel↗
PubMed1984

[Adsorption behavior of radioactive iodide and iodate in soil].

The adsorption behavior of radioiodine on soils has been studied. Soils were collected in Tokai, Ibaraki Pref . and classified with soil texture and contents of organic matter. Carrier-free radioiodine in iodide form is adsorbed on soil independent of soil properties, while radioiodine in iodate form is more readily adsorbed on soil which is abundant in organic, matter.

Adsorption↗
PubMed1984

[Determination of uranium in human tissues by the fission track method].

Several Japanese human soft tissues were analyzed for uranium by the fission track method. The tissues which were examined included lung, liver, kidney, spleen and muscle. The average concentration of uranium in the lung was estimated to be 1.86 ppb-wet and was the highest of all the tissues analysed. The results of the present work are consistent with the reported values for U.K. and U.S.A. human tissues.

Adult↗
PubMed1983

Difference equation model of ventricular parasystole as an interaction between cardiac pacemakers based on the phase response curve.

A model of extended ventricular parasystole proposed by Moe et al. (1977) was formulated as a system of nonlinear difference equations by using the phase response curve of myocardial pacemakers. A number of ECG patterns of ventricular arrhythmia such as bigeminy, trigeminy etc. were explained from the property of periodic solutions of the equation. Characteristic properties of special kinds of arrhythmia called "concealed bigeminy" and "concealed trigeminy" were derived mathematically by assuming the model, in relation to the equation of the analog neuron model. The present study was considered to be of clinical significance as a theoretical foundation for the study of genesis of cardiac arrhythmias.

Arrhythmias, Cardiac↗
PubMed1983

Classification of alpha 2-HS-glycoprotein (alpha 2HS) types by isoelectric focusing.

A sample of 300 sera from unrelated individuals from Northern Japan was examined by isoelectric focusing on polyacrylamide gels. Three common types, alpha 2HS 1-1, 2-1, and 2-2 were differentiated. The frequencies of the alpha 2HS alleles in our sample were found to be: alpha 2HS1 = 0.7250 and alpha 2HS2 = 0.2750. Analysis of 16 parents with 21 children did not show deviations from the expected mode of inheritance.

Alleles↗
PubMed1983

An optimal method for calculation of the frontal-plane vector from the data of the standard and unipolar limb leads.

An optimal estimation of the frontal-plane cardiac vector (R, theta) was derived from the scalar ECG data of the standard and unipolar limb leads by the least square method which minimized the sum of squares of measurement errors of each lead data. The optimal vector was given by R = (Formula: see text) with V1, V2, V3, Vr, Vl and Vf being the measured values of the lead data. This estimation is optimal in that it coincides with the center of gravity of the vector obtained by using the two-lead data. A statistical evaluation of the reduction in measurement errors was performed.

Electrocardiography↗
PubMed1983

Theoretical analysis of "metabolic indices" of blood buffer system.

The well-known base excess (BE) and buffer base (BB) curves of Siggaard-Andersen's nomogram are based on their empirical finding that the blood buffer lines in the pH-log PCO2 coordinates with the same BE (or BB) always pass through a single point irrespective of the hemoglobin concentration. We have analytically derived the BE and BB curves on the assumption of a two-compartmental model of blood buffer system comprised of plasma and red blood cells. These hyperbolic functions of BE and BB curves fitted the Siggaard-Andersen's observation very well. The simple formulas derived from the buffer equation with the parameters obtained on the least-square basis were shown to estimate "metabolic indices" of blood as accurately as the computer reading of the nomographic curves. These results seem to indicate that the buffer equation based on the two-compartmental model describes the acid-base status of blood satisfactorily, and that it can entirely replace the Siggaard-Andersen's nomogram.

Acid-Base Equilibrium↗