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Biomedical subjects

T O-Uchi

Publications and source records attributed to T O-Uchi.

43 records · Page 3Linked to original sources
PubMedDate not supplied

Further study of physical exercise and locomotor balance compensation after unilateral labyrinthectomy in squirrel monkeys.

The effect of physical exercise on compensation for locomotor asymmetry after unilateral labyrinthectomy was studied in squirrel monkeys. Five monkeys were assigned to the motor-driven rotating cage exercise, and another five, non-exercise control. Daily exercise (cumulative time of 2 1/2 hours) was given for three weeks preoperatively and continuously (daily) post-operatively. The average number of calendar days to attain the locomotor balance compensation was 20 days in the exercise group, and 35 days in the non-exercise control group. Statistical analysis showed the former compensated (according to the previously established criterion) significantly faster than the latter ( less than 0.05). Furthermore, faster reduction of gait deviation was found in the exercise group. Therefore, when physical exercise was given extensively and continuously, and locomotor balance function was measured by the squirrel monkey platform runway test (Igarashi, 1974), physical exercise application enhanced the locomotor equilibrium compensation.

Animals↗
PubMedDate not supplied

Volumetric and dimensional measurements of vestibular structures in the squirrel monkey.

Temporal bones of squirrel monkeys which were sectioned either in the routine horizontal plane or in the exact plane of lateral semicircular canal, were used for the volumetric and dimensional measurements. Endolymphatic volumes of utriculus, sacculus, lateral ampulla, lateral semicircular duct, and some related perilymphatic volumes were measured with the aid of a computer. The sizes of the duct-ampulla junction, ampulla-utriculus junction, duct-utriculus junction, etc. were also measured. The endolymphatic volume in the lateral ampulla was about 50% greater than that in the lateral semicircular duct. The endolymphatic volume involved in the rotation in the lateral canal plane was 2.188 mm3. Among those the utriculus was about half and the other half was the ampulla plus the duct. Furthermore, we measured the circumferences of the membranous semicircular ducts both in freshly dissected materials and in processed temporal bones. A statistically significant difference (p less than 0.01) was found between them. The actual tissue shrinkage factor was 9.2-9.3%.

Animals↗
PubMedDate not supplied

The squirrel monkey stabilimetry.

In order to characterize postural ataxia associated with peripheral vestibular lesions, we have developed a T-perch recording system suitable for squirrel monkeys (tree-living primates). This system includes strain gauges for detecting movement of the vertical shaft in the directions of anterior-posterior and left-right. Simultaneously we recorded electroencephalogram (EEG), vertical eye movement, electrocardiogram (ECG) and respiration (by pneumography). Representative Dynographic records (obtained during sleep) after unilateral and bilateral (two-staged) labyrinthectomy showed the frequent occurrence of phasic body movements: slow deviations to the lesion side and the frontward and subsequent quick rightings which occurred almost synchronously with the sleep becoming shallow (judged by EEG).

Animals↗
PubMedDate not supplied

Utricular and saccular volumetry in human temporal bones.

Using serially sectioned human temporal bones, endolymphatic volumes of utriculus and sacculus were measured with the aid of a computer. The mean of the utricular volume was 8.187 mm3, and the saccular volume, 2.096 mm3. The former was 3.9 X the latter. The surface area of the macula utriculi was 3.271 mm2, and the macula sacculi was 2.188 mm2. The former was 1.5 X the latter. The study using pathologic temporal bones (Meniere's disease, otosclerosis, and otitis media chronica) showed that the utricular volume could indeed increase, and the saccular membrane was found to be more fragile than the utricular membrane in those diseased conditions.

Child, Preschool↗
PubMedDate not supplied

Vestibular-visual conflict sickness in the squirrel monkey.

When combined vestibular and visual (optokinetic) stimuli were given to squirrel monkeys in a direction and phase mismatching sinusoidal mode (in yaw plane), five of six monkeys exhibited actual emesis during three repeated exposures on separate trial days. Two animals vomited on two trial days and three animals, on one day. The incidence took place in 38.9% of the total trial days. When the identical vestibular and visual stimuli were given individually, the effect was negligible, thus confirming each stimulus magnitude was not stressful enough to produce emesis when used separately.

Animals↗
PubMedDate not supplied

Otoacoustic emission as an indicator in evaluating inner ear impairments.

Stimulated otoacoustic emissions (OAEs) were recorded from subjects with various kinds of sensorineural loss. The interaural difference in the value of the OAE pseudothreshold was significantly higher in unilateral inner ear impairments, in which there was a positive correlation between the interaural difference in the values of the psychoacoustic threshold and of the OAE pseudothreshold. There were no interaural differences of OAE in the cases of unilateral functional deafness. The measurement of OAE may serve as an indicator for evaluating sensorineural hearing losses.

Acoustic Stimulation↗