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Biomedical subjects

G Maeda

Publications and source records attributed to G Maeda.

23 records · Page 2Linked to original sources
PubMed1981

Oxidative metabolism during and following ischemia of cat spinal cord.

Spinal cord ischemia was produced by an occlusion of the thoracic descending aorta on experimental cats for the periods of 3, 5, 10, and 15 minutes. The reduction/oxidation (redox) ratio of cytochrome a,a3 was measured in vivo by reflectance spectrophotometry, simultaneously with the measurement of the following: blood pressure in the aorta distal to the occlusion; relative blood volume in the cord; oxygen tension in cord tissue; and cord potential in response to dorsal root stimulation. During aortic occlusion, the maximum increase in the redox ratio was reached somewhat more slowly than the maximum decrease in blood pressure, blood volume, and oxygen tension. Interneuron potentials began to decrease as the redox level increased, and completely disappeared soon after the redox ratio increased, and completely disappeared soon after the redox ratio increased maximally. During ischemia, therefore, oxygen consumption in the mitochondria was slightly lower than the decrease in oxygen tension; impairment of ADP phosphorylation, and accordingly that of ion pump, occurs simultaneously with the increase in the redox ratio. Recovery of the redox ratio after completion of aortic occlusion was also slightly slower than the recovery of blood pressure, blood volume, and oxygen tension. Complete recovery of interneuron potentials was much more delayed than that of the redox ratio; after 15-minute ischemia, uncoupling of ADP phosphorylation was noted. It can be concluded that the spinal cord function and metabolism are severely impaired after 15-minute occlusion.

Adenosine Diphosphate↗
PubMed1976

Design for a micropowered multichannel PAM/FM biotelemetry system for brain research.

A design for a 12-channel pulse amplitude-modulated/FM biotelemetry system is described. The biotelemeter mounts on an animal's head close to the electrode probes to record and transmit brain electrical data. The size of the unit is 4.5 x 6.5 x 2 cm and it weighs about 60 g. It is designed to acquire EEG and other physiological data where the requirement is to obtain bioelectrical activity without cable encumbrance or confining behavioral restrictions. The telemeter consumes about 800 muW of power and operates for approximately 3 continous days before it is necessary to exchange the utilization of complementary metal oxide semiconductor (CMOS) integrated circuits. Transmission range is typically about 10 m.

Animals↗