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Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

At least 1,171 records · Page 65Linked to original sources
PubMed1980

Establishment of an Experimental System for the Study of Tracheary Element Differentiation from Single Cells Isolated from the Mesophyll of Zinnia elegans.

Single cells were isolated mechanically from the mesophyll of adult plants and of seedlings of Zinnia elegans L. cv. Canary bird. When single cells isolated from the first leaves of seedlings were cultured in a liquid medium in the dark with rotation, they differentiated to tracheary elements with a reasonable degree of synchrony in the 24-hour period between days 2 and 3 after culture. The proportion of tracheary elements as a percentage of total cells reached nearly 30% 3 days after culture. Factors favoring cytodifferentiation were certain optimum levels of both alpha-naphthalene-acetic acid (0.1 milligram per liter) and benzyladenine (1 milligram per liter), a low concentration of ammonium chloride (0 to 1 millimolar), and an initial cell population density in the range 0.4 to 3.8 x 10(5) cells/ml. It was possible to follow analytically the sequence of cytodifferentiation in individual cells in this system.

Journal Article↗
PubMed1980

Direct Evidence for Cytodifferentiation to Tracheary Elements without Intervening Mitosis in a Culture of Single Cells Isolated from the Mesophyll of Zinnia elegans.

A serial observation of the process of tracheary element differentiation from single cells isolated from the mesophyll of Zinnia elegans L. cv. Canary bird provided the first direct evidence for the cytodifferentiation without intervening mitosis. Percentage of the tracheary elements formed without cell division was about 60% of total tracheary elements formed on the 4th day of culture. The number of tracheary elements formed without intervening mitosis was not reduced in the presence of colchicine at the concentrations blocking cell division. These facts clearly indicate that cell division is not a prerequisite for tracheary element differentiation in this system.

Journal Article↗
PubMed1980

Effect of gamma-oryzanol on serum TSH concentrations in primary hypothyroidism.

A single oral dose (300 mg) of gamma-oryzanol extracted from rice-bran oil produced a significant reduction on the elevated serum TSH levels in hypothyroid patients. Similarly, chronic treatment with gamma-oryzanol resulted in decreased serum TSH levels in 6 of 8 patients. There was no change in the serum levels of thyroxine-iodine and triiodothyronine during the study. In addition, there was no difference in the serum TSH response to TRH in hypothyroid patients and normal subjects. These observations suggest that gamma-oryzanol inhibits serum TSH levels in patients with primary hypothyroidism, possibly by a direct action at the hypothalamus rather than the pituitary.

Adult↗
PubMed1980

Clofibrate and a related compound suppress TSH secretion in primary hypothyroidism.

A single oral dose of the hypolipidaemic agent ethyl-p-chlorophenoxyisobutyrate (clofibrate, 750 mg) produced a significant reduction on the high basal serum TSH level in patients with primary hypothyroidism. There was no consistent change in serum levels of thyroxine-iodine (T4-I), triiodothyronine (T3) and per cent free T4 (%FT4) during the study. On the other hand, clofibrate failed to produce discernible changes in the basal and TRH-induced TSH secretion in euthyroid subjects. Similar results were also obtained with the centrally active drug meclofenoxate hydrochloride (MH, 750 mg, drip infusion), similar in structure to clofibrate. These findings suggest that clofibrate and MH inhibit TSH secretion in patients with primary hypothyroidism, possibly by a direct action at the hypothalamic or pituitary level.

Adult↗
PubMed1980

[Studies on the performance of the dental air turbine handpieces. (Part 3) Torque measurements of the air turbine handpieces (author's transl)].

Air turbine handpieces, electro-micro motors and electric engines are widely used as the dental cutting instruments for the clinical use. So, this paper examined the measurement of rotational torque of the high speed dental instruments used for cutting works. For the measurement of torque of the dental instrument, we have measured the pushing load of the test but as used for cutting tools. But, in this paper, we attempted the new trials which are the measuring the tangential force of test bur rotated with the high speed velocity. And then, the kinetic energy values of rotational bur are obtained with using the value of the test bur's rotational torque. Besides we examined the interrelations of the rotational torque and pushing as the results, and both measurement value show the good relations for air turbine handpieces.

Air↗