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Biomedical subjects

Y Harada

Publications and source records attributed to Y Harada.

At least 757 records · Page 42Linked to original sources
PubMed1983

Experimental study of denervated rat muscle. Part I: Histochemical and electrophysiological observations of denervated rat muscle.

Histochemical and electrophysiological observations were carried out on denervated rat muscles, mainly extensor digitorum longus muscle. The myofibrillar ATPase reaction was employed to classify the type of muscle fibers. Type 1 fiber, low ATPase activity, and type 2 fiber, high ATPase activity, were recognized. It is generally believed that denervation causes a preferential atrophy of type 2 fibers and these fibers may be more dependant on neural influence than type 1 fibers. But the result of this investigation revealed that the atrophy of type 1 fiber and the enlargement of type 2 fiber will be caused by denervation. The term of enlargement is not equivalent to hypertrophy. Enlargement means the increasing of diameter of muscle fiber reacting to the denervation in this experiment. It is deduced that type 1 fiber is affected more by neural control than type 2 fiber.

Adenosine Triphosphatases↗
PubMed1983

Experimental study of denervated rat muscle. Part II: The effects of electrical stimulation on the denervated rat muscles.

Electrical stimulation has been widely employed for the treatment of peripheral nerve lesion, however, its effects are not well known. Effects of electrical stimulation on denervated muscles were studied by measuring the weight of anterior crural muscles and the diameter of muscle fibers of the extensor digitorum longus muscle of the rat. The muscle fibers were classified by myofibrillar ATPase reaction. The denervated muscle showed loss of weight, a marked decrease in diameter of type 1 fibers and a small increase in diameter of type 2 fibers. Electrical stimulation suppressed weight loss of the denervated muscles. Electrical stimulation with high frequency cycle, like phasic motoneuron discharges, significantly suppressed the increase in diameter of type 2 muscle fibers. Electrical stimulation with low frequency cycle, like tonic motoneuron discharge, significantly suppressed the decrease in diameter of type 1 muscle fibers.

Adenosine Triphosphatases↗
PubMed1983

[Clinical experience with cefotiam in otorhinolaryngologic infections].

Clinical studies of cefotiam (CTM), a new cephalosporin derivative, in otorhinolaryngological field were performed, and the results were summarized as follows. CTM was intravenously injected to 31 cases of otorhinolaryngological infections in daily dose of 1--4 g. Clinical efficacy was 33.3% in acute otitis media and chronic otitis media (acute exacerbation) (6 cases), 90% in acute tonsillitis (including peritonsillitis, peritonsillar abscess) (20 cases), 50% in acute pharyngitis (2 cases), 100% in acute sinusitis (2 cases) and 100% in epiglottis abscess (1 case), respectively. Bacteriological efficacy was 80% for beta-Streptococcus, 100% for K. pneumoniae, 50% for P. aeruginosa, and 85.7% for Peptococcus and Peptostreptococcus, respectively. No difference was observed in various daily doses for clinical efficacy. As for side effects and laboratory findings, eruption in 1 case, elevation of GOT in 1 case and elevation of GOT, GPT in 2 cases were observed. But, all of the cases were normalized after stoppage of administration or postadministration.

Adult↗
PubMed1983

Scanning electron microscopy of the nerve endings of Corti's organ.

Scanning electron microscopy (SEM) study of the innervation of the organ of Corti has been carried out for many years. Various methods have been used in attempts to observe more details of the endings of nerve fibers on the sensory hair cells. In this study, a new method of microdissection of Corti's organ was done using a small piece of double-sided adhesive tape. This method is simple and facilitates observation of Corti's organ from the basal to the apical turns. Using it we found variations of the nerve endings and the Deiters' cells in each half turn beginning from the lower basal turn to the upper fourth turn. Nerve endings at the lower poles of outer hair cells are arranged in clusters, and are reduced in size and number as the upper turn is approached. On the contrary, the Deiters' cells are increased in size toward the upper turn, therefore nerve endings in the upper turn are often covered by Deiters' cells. Small nerve endings high on the side of the outer hair cell were also observed. Although there was clear evidence of ultrastructural change in the hair cells' cilia after administration of ototoxic drugs or after hyperstimulation by sound, there was no evidence of concomitant ultrastructural change in the nerve endings. Nerve endings appeared to be more resistant than the hair cells.

Acoustic Stimulation↗
PubMed1983

[Experimental study on spinal cord monitoring--changes in spinal cord evoked potentials during vertical direction distraction of the spinal cord].

Experiments were carried out on 18 adult dogs ranging from 9.0 to 11.5 kg. The dogs were intubated and anesthetized with Halothene oxygen, and then mounted on a stereotaxic spinal apparatus. Facetectomies and a discectomy between L1 and L2 vertebrae were performed readily to give traction force to the spinal cord. Spinal cord function was monitored by the first and second negative deflections (I and II, respectively) of the descending spinal cord evoked potentials (descending SCEP) elicited at T7 and recorded at L4 through bipolar catheter electrodes. Both of them were inserted at the midline of the dorsal epidural space. The study was conducted in two parts. In the first part, the cyclic distraction-release program was carried out until motor function was impaired. Distraction was increased in increments of 5 mm, each time maintained for 10 minutes and then totally released for 10 minutes. If neurological deficits in the hind limbs were confirmed by the wake-up test, which was performed every 10 minutes after distraction and release, the 10 minutes' release period was extended for a total period of 30 minutes. The first change in the experimental protocol was transient augmentation of the amplitude of the II deflection which was always observed on a slight distraction, while the I deflection did not change in its amplitude and latency. Each distraction produced a reversible slight reduction of the amplitudes with delay of latencies of the I and II deflections before motor disturbance occurred. However, at a certain traction level paraparesis accompanied by irreversible decrease of amplitudes and delay of latencies was observed, which was confirmed by the wake-up test. At this point, which was designated as the critical point, SCEPs were so time dependent that only a slight amplitude reduction was noted immediately after distraction, but it decreased quickly in a short time during this traction level. Histopathology and microangiography did not show any hemorrhage in the spinal cord of any of the specimens, although there were formation of perivascular space, rupture of a part of nerve fibers in the white matter and findings of acute degeneration in the grey matter. In the second part of this study, a small amount of distraction was introduced until the amplitude of the II deflection depicted transient augmentation, which had a mean amplitude of 167.8 per cent as compared to the control. This enhancement returned approximately to the normal value within 10 minutes by total release.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1983

[A successfully operated case of atrial septal defect with pheochromocytoma].

A 16 year-old male, who had marked hypertension and complained of palpitation, hyperhidrosis, headache and weight-loss, was diagnosed as atrial septal defect with pheochromocytoma. The first operation was performed for tumor on September 3, 1981. The hemodynamic change was recorded through the operation. The total systemic peripheral resistance and the total pulmonary resistance were improved after surgery. The systemic and pulmonary blood pressure were also decreased to normal level after surgery, although pulmonary arterial flow was increased. On one hundred and third day after this operation, radical correction for the cardiac malformation was performed. Operative and postoperative course were uneventful and the patient is free from all untoward complaints at this moment. Blood or urine catecholamine levels have also improved and are within normal limits.

Adolescent↗