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Biomedical subjects

O Sato

Publications and source records attributed to O Sato.

At least 289 records · Page 16Linked to original sources
PubMed1975

[A new method of autotomography in cerebral angiography (author's transl)].

Acompanied with the recent advances of various techniques of cerebral angiography, the angio-tomography is now going to be recognized as one the significant techniques. But, this angio-tomography requires a special work place with tomographic equipment. Thus the applicability of the method is now limited as far as the routine use is concerned. So, the technique of autotomography is often tried as a convenient substitute for the angiotomography, because this technique is very simple and does not need any special facilities. But, as the autotomography is only possible to take the midline tomogram, it's application is strictly limited. So, we have invented a new method of the autotomography using a simple device. This device is constituted of two portions; one is a plate of rotation, and the other is a box to fasten a patient's head. By sliding the box on the plate, it is possible to move the rotatory axis to the aimed portion of the head. In this way, it is possible to take an arbitrary tomographic plane. As our device is simple and it's use is very easy, this method of the autotomography is possible to apply in a routine examination. This report describes the principle and the method of the use of our new device and demonstrates several films taken by this method.

Brain Neoplasms↗
PubMed1975

[The effect of asphyxia on the electrical and mechanical activities of the rat hindlimb muscles (author's transl)].

After asphyxia by clamping external iliac artery, the changes of electrical and mechanical activities of M. extensor digitorum longus and soleus were followed up. Although the action potential amplitude was decreased monotonously, a transient increase in twitch tension appeared, one or two minutes after start of asphyxia, which was seen more frequently and more remarkable in extensor than soleus. This was attributed to the different metabolic process of components contained in the muscle and also to their different population in two kinds of muscle fibres. It was suggested from the previous results obtained by us that the decrease of action potential amplitude, at least in the early period of asphyxia, was not due to membrane depolarization but to conformational change of Na-channel by anoxia.

Action Potentials↗
PubMed1975

Scotomatous defects in the central visual field in pituitary adenomas.

In a series of 46 cases of pituitary adenomata (34 solid, 6 with yellow cyst, and 6 with hemorrhagic cyst), we found central scotomatous field defects in 8 patients. Of these 8 scotomatous cases 4 were associated with tumour containing a hemorrhagic cyst. We suggest that rapid expansion of the tumour is one of the principal etiological factors in the production of scotomatous instead of bitemporal field defects in patients with pituitary adenomas.

Adenoma↗
PubMed1975

Bulk flow in the cerebrospinal fluid system of the dog.

Ventriculo-cisternal, intracranial subarachnoid-to-subarachnoid space and spinal subarachnoid space perfusions were carried out on dogs. The perfusate contained inulin as a tracer and the design of these experiments was based upon the concept that inulin leaves cerebrospinal fluid (CSF) compartments only by means of bulk absorption, and that actual diffusion and active transport of inulin is negligibly small. Inulin was removed from different CSF spaces by bulk absorption at rates which varied linearly with hydrostatic pressure. The rate of formation of CSF is equal to inulin clearance plus the difference between outflow and inflow rates. The total CSF formation in dogs weighing 12 to 17 kg was measured as 0.065 ml/min, and 58.5 per cent of this amount was found to come from extraventricular CSF space. The rates are independent of hydrostatic pressure in the range studied.

Animals↗
PubMed1975

Brain tumors of early infants.

The authors describe their experience with ten cases of brain tumors in children in whom the onset of symptoms occurred within the first year of life, but who were operated on when they were 2 months to 4 years of age. The series includes 5 gliomas (4 supratentorial, 1 cerebellar; 3 astrocytomas, 1 spongioblastoma, 1 ependymoblastoma), 2 teratomas of the lateral ventricle, and 3 single cases of third ventricle choroid plexus papilloma, temporal lobe sarcoma, and a parasellar craniopharyngioma. Six cases were partially removed, one of them was shunted. Only biopsy was carried out in two, one of which was shunted. The only case of radical removal was a lateral ventricle teratoma; this patient died at operation. Nine patients survived at surgery, three of whom are alive on the 3rd, 4th, and 7th postoperative year. There were two late deaths: one at 2 years (lateral ventricle astrocytoma, which was only biopsied) and one at 7 years and 3 months (spongioblastoma) following surgery. This series from a 40-year period (1933-1973) represents 0.4% of 2,832 brain tumors and 1.9% of 528 brain tumors in the pediatric age. The authors emphasize the need to treat brain tumors in early infancy and insist on the use of radiotherapy and chemotherapy when the lesions are not radically removed at surgery.

Astrocytoma↗
PubMed1975

Growing skull fractures of childhood. Possible mechanism of its focal ventricular dilatation.

Four cases of growing skull fracture are presented. Pneumoencephalography done on these cases showed a moderate to extensive degree of focal ventricular dilatation beneath the skull defect. An important factor, heretofore overlooked in explaining this focal ventricular enlargement, is our hypothesis that the force exerted on the particular area of the ventricular wall represents a pulsatile CSF movement damped in the region which is liable to yield to this compression wave in the absence of covering resistant dura mater. Because of the importance of early diagnosis in order to avoid possible delayed neurologic complications such as convulsive disorders, it is advisable to carry on repeated radiological examinations of the skull following fracture in this particular age group until the fracture heals by the progressive apposition of the bone on either side of the fractured line.

Arachnoid↗