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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 235 records · Page 13Linked to original sources
PubMed1980

Funicular orientation by electrical stimulation and internal neurolysis in peripheral nerve suture.

Eleven peripheral nerve lacerations around the wrists of ten patients were treated with funicular suture or nerve graft. In three freshly lacerated nerves funicular orientation could be made only by electrical stimulation to both cut ends. The electrophysiological method was also utilised to obtain funicular orientation of a proximal stump in eight old nerve lacerations. However, funicular orientation of the distal stump of old lacerations, which was not responsive to electrical stimulation, was performed anatomically by internal neurolysis from a terminal branching area up to a distal stump. By six months after the operation, motor and sensory functions of the patients with funicular suture had recovered to an excellent degree with rapid reinnervation.

Adolescent↗
PubMed1979

Bioelectric activity of chick stato-acoustic ganglion cells in culture.

Electrical membrane properties were recorded intracellularly from dissociated embryonic chick stato-acoustic ganglion (S-AG) cells cultivated in vitro for 8 days. Most S-AG cells exhibited the complete action potentials with overshoot by passing current and a half of them fired repetitively during single prolonged stimulation. In some S-AG cells with relatively high input resistances, long-term negative after-potentials were clearly observed at the end of repetitive discharges. The action potential was composed of fast and slow components. The former component was blocked by tetrodtoxin (TTX) and the latter one was markedly suppressed by treatment with MnCl2 or verapamil. These data indicate that the action potential from the chick S-AG perikaryon is produced by both Na and Ca mechanisms together.

Action Potentials↗
PubMed1979

Frequency analysis of heart rate variability under flight conditions.

The factors causing heart rate variability (HRV) were investigated under various kinds of workloads and flight conditions. Frequency analysis of heart rate, and cross-correlation analysis with blood pressure and respiration, were performed by using the fast Fourier analyser. Consequently, the main frequency of HRV at rest consisted of 0.1 Hz and 0.25-0.3 Hz. These fluctuations disappeared under physical loads, but the value of 0.1 Hz at first increased under moderate mental load and thereafter decreased as the mental load increased. It was suggested that the behavior of the frequency 0.1 Hz under mental load was influenced partly by higher brain centers. For the actual flight, the frequency decreased under takeoff and landing, and remained as at rest during the gunnery and acrobatic training flight. It was concluded that the evaluation of workloads under flight conditions by using the analysis of the factors of HRV was very useful to improve a man-machine interface.

Acceleration↗
PubMed1978

Serum lipid and lipoprotein abnormalities in major clinical entities of renal disease.

More than half of the patients with glomerulonephritis, nephrotic syndrome and renovascular hypertension showed obviously abnormal profiles of serum lipoproteins (Lps). The abnormal profiles returned to normal or near-normal when the disease was ameliorated or corrected surgically. A unique Lp profile (broad midband pattern, BMP) was observed in approximately 89% of uremic patients on hemodialysis therapy. The results of the current investigations indicated that the BMP could probably be formed by the accumulation of catabolic remnants of VLDL.

Adolescent↗
PubMed1978

Studies on a dyslipoproteinemia in hemodialysis patients.

Grossly abnormal serum lipoprotein (Lp) profile which appeared as a broad-midband pattern (BMP) in PAG electrophoresis was detected in 67% of uremic patients maintained by prolonged hemodialysis therapy (hemodialysis patients). It was revealed that BMP was ascribed to the presence of a discrete series of Lps which were intermediate between beta-migrating LDL and pre-beta-migrating VLDL regarding buoyant density, Sf rate, chemical composition, and behavior in electrophoresis. The results in the present study indicate that the accumulation of these Lps, which may include the previously-known Lp species such as the intermediate-density Lp or the remnant particles, is taking place in hemodialysis patients.

Adult↗
PubMed1978

Evaluation method of mental workload under flight conditions.

In order to analyze the relationship between heart rate variability (HRV) and the flight tasks of pilots, HRV of various mental and physical work stresses were investigated. For the physical stress on the treadmill, S.D. of heart rate sequence showed a minimum value at medium stresses and remained there until the maximum stress. However, the centrifuge acceleration test presupposed special physical stresses, and S.D. was almost same as the resting findings. In the tracking tasks, which presupposed maximum interpretative actions, the increase in the mean heart rate (MHR) was small with the S.D. increased a greater amount than for resting results. Consequently, preflight checks and level flight phases presupposed medium interpretative actions and mental stress with reserve capacity. Takeoff and landing phases were considered as both high interpretative action and high emotional stress situations. Acrobatic and gunnery training flight phases were considered physical load, strong interpretative actions, and emotional stress tasks.

Acceleration↗
PubMed1977

Morphological and electrophysiological changes in cultured spinal ganglion cells during development.

Morphological changes of partially dissociated chick spinal ganglion cells in culture and their intracellular responses were simultaneously observed in an attempt to investigate the correlation between cell structure and function during development in vitro. As the ganglion cells natured, their originally eccentric nuclei assumed more central positions and the surface area of cell body displayed a linear increase accompanied with an increase in cell diameter. Nissl bodies were distributed throughout the cytoplasm after 3 to 4 weeks and myelin was formed at the same period. The bioelectric properties of the ganglion cells changed in parallel with the morphological development. The passive membrane properties such as resting potentials and specific membrane resistance were increased. Action potentials could be elicited from neurons as early as 2 days in vitro, while the complete excitability was accomplished at 8 to 10 days. Moreover, the wave form of the action potenial itself was changed, that is, the amplitude and maximum rate of rise increased and the duration decreased. The alteration rates of these passive and active properties were maximum at 8 to 12 days in culture. Repetitive firing occurred after 3 to 4 weeks, though single responses were displayed by 3 weeks in culture. This changes seemed to correspond with myelin formation in vitro.

Action Potentials↗