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Biomedical subjects

T Maeyama

Publications and source records attributed to T Maeyama.

65 records · Page 4Linked to original sources
PubMed1981

A study of experimental sinusitis in rabbits.

Sinusitis was experimentally induced in rabbits by injecting one ml of casitone semi-liquid agar containing Staphylococcus aureus 209P in the order of 10(7) per ml into rabbit's bilateral paranasal sinuses (which had been sensitized with a 2.5% concentration of a purified egg white albumin solution) through a percutaneous route with a sterilized syringe. Two weeks after the last injection the rabbits were sacrificed and dissected. Light microscopic (LM) and scanning electron microscopic (SEM) examination of pathomorphological changes in this experimental model revealed that chronic inflammation developed in the mucous membranes of the paranasal sinuses at a high incidence.

Animals↗
PubMedDate not supplied

Minimal two-point discrimination in human tongue and palate.

The distribution of minimal two-point discrimination values on the tongue and soft palate was investigated in normal subjects using electric stimulation. It was performed using square pulses of 0.35 ms duration, a rate 10 Hz, a voltage between 3.5 and 7.0 with an average of 4.09 using two silver-silver chloride electrodes (tip diameter, 0.4 mm), and a strain-guage device to control crimping pressure. The spatial threshold was 1.650 +/- 0.433 mm at the tongue tip and 2.650 +/- 0.856 mm and 1.675 +/- 0.269 mm on the anterior margin of each side of the tongue. The soft palate and lingual dorsum were almost completely insensitive. Electric stimulation is a convenient method of measuring two-point limen values.

Adolescent↗
PubMedDate not supplied

Misdirected regeneration of injured recurrent laryngeal nerve in the cat.

INTRODUCTION: Misdirected regeneration (MR) frequently occurs following injury to the recurrent laryngeal nerve (RLN) resulting in neurotmesis or axonotmesis. Physiological and anatomic parameters involved in the functional recovery of the larynx following freezing injury or neurorrhaphy of the RLN were studied. A multi-facilitated approach is undertaken to clarify the functional abnormalities caused by the MR after recurrent laryngeal nerve injury. MATERIALS AND METHODS: Three groups of adult cats were studied. These included controls, cats with recurrent laryngeal neurorrhaphy, and cats with recurrent laryngeal nerve freeze injuries. From 2 weeks to 9 months after the nerve injury, the animals were studied endoscopically and with electromyography (EMG). Using the same animal, the number and location of motoneurons supplying the ipsilateral posterior cricoarytenoid (PCA) muscle were examined with horseradish peroxidase (HRP). Animals were subsequently sacrificed to study the pattern of reinnervation. RESULTS: Following neurorrhaphy all cats had vocal cord paralysis. After neurorrhaphy, effective motion function did not return in the affected vocal cord and it remained fixed in the paramedian position. Although EMG of the laryngeal muscles of the affected side showed interference voltage, the pattern of activities was markedly different from that of the unaffected side, and reciprocity among the laryngeal muscles was not restored. The number of PCA motoneurons recovered to the normal range, but a considerable number of neuronal bodies were dispersed outside the normal PCA area. This indicates misdirected reinnervation to the PCA muscle by motoneurons that originally served other laryngeal muscles. In the freezing injury, effective vocal cord movement finally recovered after 6 months. At this time, EMG showed a normal pattern, although a relatively small amount of misdirected neurons was observed. DISCUSSION: Functional recovery of vocal cord motion does not occur following neurorrhaphy. Prominently disorganized arrangement of laryngeal motor neurons was observed in the horseradish peroxidase study. This suggests that inappropriate reinnervation develops in spite of reapproximation and suturing. Altered central organization of the motor nucleus is a significant pathogenic factor in the loss of laryngeal muscular coordination following recurrent laryngeal nerve lesions. The degree of recovery is related to the mechanism of injury.

Animals↗
PubMedDate not supplied

Experimental study on expanded polytetrafluoroethylene (E-PTFE) for portal vein reconstruction with combined operation of the digestive tract.

For evaluating the resistance of Expanded Polytetrafluoroethylene (E-PTFE) to infection, an E-PTFE vascular graft was exposed to intestinal contents and transplanted into the canine portal vein. In group A, E-PTFE tubular graft was inserted into the portal vein defect. In group B, choledochojejunostomy was also performed combined with the E-PTFE graft interposition. In an early stage infiltration of leukocytes was observed around the graft removed from the dog. However, exploration of the periprosthetic adventitial attachment revealed no infiltration of leukocytes in both groups more than three months after operation. The results showed no morphological difference in the formation of neointima and no statistical discrepancy of patency rates (X2-test; 0.5 less than p less than 0.75). These results demonstrated superiority of the E-PTFE vascular substitute in terms of being antithrombogenic and refractory to infection.

Animals↗