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Biomedical subjects

T Kuroda

Publications and source records attributed to T Kuroda.

At least 451 records · Page 25Linked to original sources
PubMed1979

Growth behaviour of condylar cartilage and epiphyseal cartilage on the different medium of the organ culture.

In order to compare histological differences between the condylar and epiphyseal cartilages, an organ culture system was employed. Materials from 36 neonatal rabbits were cultured for 7 days on three different, chemically defined media (Ham F12, Medium 199, and Eagle's minimum essential medium) with the addition of various concentrations of ascorbic acid, fetal calf serum and NaHCO3. The epiphyseal cartilage was maintained in situ histological and biochemical features better than the condylar cartilage on any of the medium used. The maximum sensitivity to Toluidine Blue staining of the cultured condylar cartilage was observed on Ham F12. For both the condylar and epiphyseal cartilages, Ham F12 with the addition of 50 microgram/ml ascorbic acid and higher concentration of NaHCO3 was more effective on the maintenance of cell organization. However, effect of the addition of fetal calf serum to the medium was quite different between the condylar and epiphyseal cartilages, that is, the former showed better histological features without the addition, but the latter showed features similar to that in situ with 20% addition of fetal calf serum.

Animals↗
PubMed1979

Growth of condylar, epiphyseal and spheno-occipital synchrondrosal cartilages cultured on medium BGJ.

The purpose of this experiment was to examine the growth of condylar, epiphyseal, and spheno-occipital synchrondrosal cartilages cultured on medium BGJ. Materials from 12 neonatal rabbits were cultured for 7 days on this medium with the addition of 0, 10, or 20% fetal calf serum. Epiphyseal cartilages cultured with the addition of 20% fetal calf serum showed slightly better maintenance of in situ state, though little morphological changes were observed during 7 days. Spheno-occipital synchondrosal cartilages cultured with the addition of 10% or 20% fetal calf serum were histologically relatively similar to in situ state than those cultured without fetal calf serum, but no growth in length and width of these cartilages was observed. On the other hand, cultured condylar cartilages showed the least maintenance of histological and histochemical features. It was assumed that medium BGJ was not a recommendable medium for the organ culture of condylar cartilage.

Animals↗
PubMed1977

Responses of crayfish muscle preparations to nerve stimulation with various patterns of impulse sequence. Effects of intermittent, intercalated and adaptational types of impulse sequence.

The present study was carried out with an attempt to see what effects would be produced by various patterns of impulse trains other than pulses of a definite frequency in nerve-muscle systems of the crayfish. Single axons of nerves of the opener, the slow closer and the fast closer of the crayfish claw were stimulated and the tension development of muscles were recorded. The impulse trains tested are as follows: (i) intermittent stimulation; e.g., paired (doublet) and triplet stimuli, (ii) the intercalated stimulation during stimulation by constant-frequency pulses and (iii) the adaptational type of stimulation, i.e. a train of pulses of which interval gradually increases as seen in the process of the adaptation in the sensory nerve. Results obtained are as follows. Intermittent doublet stimuli produced a greater tension than the monotonous stimulation of the same average frequency. Repetitive triplet or quadruplet stimuli caused further increments in the tension development. Intercalation of a stimulus during usual monotonous stimulation induced a catch-like effect on the tension. Intercalated triplet stimuli provoked a stronger catch action. With the adaptational type of stimulation, an initial rapid tension development occurred with a least latency and this was followed by a maintained tension. There are certain temporal configurations of stimuli which produced a greater tension or a more physiologically meaningful time course of tension development. This suggests the significance of nervous coding.

Animals↗
PubMed1977

Effect of stimulation with impulse trains of various patterns, including adaptational type, on frog's nerve-muscle and spinal reflex preparations.

The train of discharge in the nerve in the integrated nervous function is known to have a variable pattern. The question still remains open as to whether the pattern of discharge sequence plays some role like a word in communciation. The present study aimed to investigate the relationship between stimuli with various sequences and responses. The intermittent, intercalated and adaptational types of stimulation were given to the efferent or afferent nerves, and the tension of muscles of a nerve-muscle or a spinal reflex preparations of frogs was recorded. Enhancement of tension was observed when the appropriate intermittent or intercalated stimulation was applied. In the nerve-muscle preparation, this effect was made clearly detectable when the nerve-muscle preparation was equilibrated with calcium-deficient Ringer solution. An appropriate type of adaptational stimulation evoked a rapid and long-lasting tension development which may be of physiological meaning in emergency. This fact may give a guide when man stimulates the nerve to examine the response.

Adaptation, Physiological↗
PubMed1976

Effects of deuterium oxide on mechano-sensory receptor.

In the crayfish stretch receptor organ, a total substitution of D2O for H2O in the bathing solution produced a decrease in the amplitude of the receptor potential to a level of 34% of the control. The electrical resistance of the receptor neuron was slightly increased by the D2O substitution. The input capacitance of the neuron was unchanged. The viscoelastic properties of the receptor muscle were not altered by D2O. Thus, we conclude that D2O has an inhibitory effect on the transduction process which links the deformation of the dendrites with the permeability increase that is responsible for the receptor potential.

Action Potentials↗