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Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

At least 1,153 records · Page 64Linked to original sources
PubMed1981

TSH and prolactin secretions in Hashimoto's thyroiditis following withdrawal of thyroid hormone therapy.

Changes in the pituitary-thyroid axis in patients with Hashimoto's thyroiditis following withdrawal of thyroid suppressive therapy were analyzed. The group of patients with thyroid adenoma served as control (group I). Patients with Hashimoto's thyroiditis were divided into 2 groups on the basis of serum TSH levels 8 weeks after discontinuing the exogenous thyroid hormone (group II, less than 10 microunits/ml; group III, more than 10 microunits/ml). During treatment with L-T4(200 micrograms/day) or L-T3(50 micrograms/day), there was no significant difference in serum T4-I and T3 levels among the three groups. Following L-T4 withdrawal, basal serum TSH levels were higher at 2 to 8 weeks in groups II and III than in group I. Serum TSH response to TRH was greater at 4 to 8 weeks in groups II and III than in group I. Following L-T3 withdrawal, basal serum TSH levels were higher at 1 and 2 weeks in group II than in group I, while those of group III were consistently higher during the study. Higher TSH responses to TRH were observed at 1 to 8 weeks in groups II and III. Neither basal nor TRH-induced prolactin (PRL) secretion differed significantly among the three groups. We have demonstrated that pituitary TSH secretion in patients with Hashimoto's thyroiditis is affected more by withdrawal of thyroid hormone therapy than in patients with thyroid adenoma. In addition, the present findings suggest a difference between the sensitivity of thyrotrophs and lactotrophs in Hashimoto's thyroiditis after prolonged thyroid therapy is discontinued.

Adenoma↗
PubMed1981

Magnitude of suppression of binocular rivalry within the invisible pattern.

How the magnitude of the suppression effect in binocular rivalry is shared within the completely invisible pattern was studied. Accuracy of detecting a target presented in the invisible pattern was measured at each of two positions of the target combined with two positions of the fixation point. The target which was presented at the periphery of the suppressed invisible pattern was detected more accurately than that presented at the center regardless of the position of fixation.

Dominance, Cerebral↗
PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 4) Analysis of the rotational performance of air turbine handpieces (N = N0 - CvFv gamma (author's transl)].

By the introduction of the diamond instruments and carbide burs measurably improved the quality and ease of cavity preparation, the several kinds of the air turbine handpieces, that is, standard type, torque type and miniature type air handpieces have been recently developed. In this paper, the performance tests of these air turbine handpieces have been carried out, and obtained the relations are indicated speeds and the vertical and horizontal loads or torque using the test bur. These relations are indicated by the logarithmic expressions, N = N0 - CvFv gamma, where N is the rotational speed of the air turbine handpieces during rotation, N0 is the free rotational speed of the air turbine handpieces, Fv is the vertical loads on the tests burs and Cv and gamma is the experimental constants. And then, the maximum performed work or the air turbine handpieces is presented by the expression as follows. W max = pimicrod/60(1/Cv)1/ gamma gamma (N0/gamma + 1)(1 + gamma)/gamma And we proposed the formula to be calculated for the performance ability of the air turbine handpieces.

Dental High-Speed Equipment↗
PubMed1981

[Studies on the performance of the dental air turbine handpieces. (Part 5) Rotational performance of various kinds of dental air turbine handpieces (N = N0--CvFv gamma) (author's transl)].

Making research on the rotational performance of the dental air turbine handpieces widely used for dental cutting instruments, we investigated with the relation between rotational speed and load on many kinds of dental handpieces used for clinical divisions and with the applications of the theoretical equations to have be shown in the previous report. And then we have the investigation on these properties. Dental handpieces to measured with these properties were classified the four types, standard types, torque type, miniature type and air bearing type. And we applied the experimental equations to these experimental values and determined the rotational coefficients, gamma and Cv. The rotational speed N and normal force Fv, which occurred the maximum work of air turbine handpieces, were calculated with our analysis and then these values of N and Fv were compared with the experimental results. These results, that is, experimental and calculated values have a good agreement and the development of the theoretical approach is useful for the estimation of the rotational performance. And we examined the possibility of rotational performance's estimation with the process of simple experiment on these air turbine handpieces.

Dental High-Speed Equipment↗
PubMed1980

Effect of acriflavine on the hexokinase isozyme pattern of a yeast, Hansenula jadinii.

Dried cells of a yeast, Hansenula jadinii, that had been cultured aerobically with acriflavine, contained three hexokinase isozymes and metabolized glucose at 0.6 M to produce ATP to phosphorylate nucleotides in the presence of a high concentration of phosphate. Dried cells cultured aerobically without acriflavine contained two hexokinase isozymes and could not metabolize glucose under the same conditions. Two of the isozymes of the yeast cultured with acriflavine were similar to isozymes of the yeast cultured without acriflavine. However, the third isozyme was resistant to a high phosphate concentration and caused regeneration of ATP through glycolysis and phosphorylation of nucleotides.

Acridines↗
PubMed1980

Replacement of K+ with Rb+ or Cs+, and its effects on the mechanical responses to norepinephrine and methacholine in the rat vas deferens.

The rat vas deferens was stored overnight in cold, K+-free Krebs solution to deplete intracellular K+ then incubated in K+-, Rb+-, or Cs+-containing Krebs solution at 37 degrees C to load these ions inside the cells. After 4 h, the contents of K+ or Rb+ reached the level of K+ in the fresh vas deferens; the content of Cs+ was less than half that of the fresh vas deferens. Dose-response curves to norepinephrine and methacholine were determined under these conditions, and the curves in Rb+ or Cs+ solution were compared with those in K+ solution. The cold storage per se had little effect on the dose-response curves in K+ solution except that it slightly decreased the maximal response to norepinephrine. The dose-response curves in Rb+ solution were to the left of those in K+ solution. The maximal response to methacholine was greatly increased. On the other hand, the dose-response curves in Cs+ solution were to the right of those in K+ solution. The maximal responses were greatly decreased with both drugs. The results suggest that Rb+ but not Cs+ can fully substitute for K+ in the rat vas deferens response to norepinephrine and methacholine.

Animals↗
PubMed1980

Purification and enzymatic properties of glyoxylate reductase II from baker's yeast.

Glyoxylate reductase II was purified about 2,400-fold from a cell extract of baker's yeast by protamine sulfate treatment, and column chromatographies on DEAE-cellulose, hydroxylapatite, Sephadex G-150, and phosphocellulose. The purified enzyme was electrophoretically homogeneous. The molecular weight was determined to be approximately 65,000 by gel filtration. The enzyme was greatly stabilized by the addition of 20% (v/v) glycerol. It catalyzed the reduction of glyoxylate and hydroxypyruvate and was specific for NADPH as an electron donor, but showed slight affinity towards NADH. The Michaelis constants for glyoxylate, hydroxypyruvate, NADPH, and NADH were found to be 16mM, 1.4 mM, 5.7 microM, and 0.43 mM, respectively. The enzyme was inhibited by p-chloromercuribenzoate (PCMB) and iodoacetate, but inhibition was prevented by dithiothreitol (DTT) or L-cysteine. The reduction of glyoxylate and hydroxypyruvate was not stimulated by anions.

Alcohol Oxidoreductases↗