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Biomedical subjects

K Amano

Publications and source records attributed to K Amano.

At least 397 records · Page 22Linked to original sources
PubMed1980

[Anatomical identification of horizontal sections on computed tomogram utilizing Schaltenbrand and Bailey's atlas of the human brain (author's transl)].

Difference in angles between horizontal section of Schaltenbrand & Bailey's atlas and horizontal section of CT based on Cantho-Meatal line is only 3.5 to 5.5 degrees. Therefore, the horizontal section of Schaltenbrand & Bailey's atlas can be utilized for analysis of the horizontal section of CT scan, because the basal ganglia are located approximately in the center of the cranial cavity. The lesions at the basal ganglia with superimposing technique utilizing the relation between horizontal section of Schaltenbrand & Bailey's atlas and analogue view of CT can be identified anatomically.

Adult↗
PubMed1979

[A case of multiple fusiform aneurysms presenting homonymous hemianopsia (author's transl)].

Fusiform Aneurysms are encountered in elderly persons with advanced arteriosclerosis. When they are enlarged to compress the neighboring structures, they may resemble tumors symptomatically. Especially when situated in close relation to the optic nerve or chiasmatic region, pituitary tumor is likely to be suspected. This is a case of 62 year old female with a giant fusiform aneurysm of the right internal carotid artery extending to the middle cerebral artery which caused left homonymous hemianopsia and a large aneurysm in the cavernous portion of the left internal carotid artery with fusiform extension of the distal portion of the carotid artery which presented left blepharoptosis, dilated pupil and total ophthalmoplegia. The basilar artery and the right meningohypophyseal artery showed fusiform dilatation as well. Systemic atherosclerotic change, abdominal aortic aneurysm, nephrosclerosis were also accompanied. The computed tomography demonstrated the aneurysms distinctly. Left oculomotor palsy disappeared after six months with residue of left homonymous hemianopsia. Surgical intervention was not attempted, because of the widely distributed constitutional aneurysms in the whole body.

Carotid Artery, Internal↗
PubMed1978

A case of epidermoid of the fourth ventricle.

The case of woman, aged 52, who had a fourth ventricular epidermoid, which eluded definite diagnosis for six years because of spontaneous remissions, is reported. Computed tomography may be misleading in such cases with spontaneous remission of symptoms because of the low electron density of the tumor which is not enhanced by intravenous contrast medium. Other diagnostic means such as ventriculography should not be neglected.

Cerebral Ventricle Neoplasms↗
PubMed1978

Boron-neutron capture therapy in relation to immunotherapy.

The essential feature of tumour therapy rests upon host-tumour interaction. To achieve therapeutic effects, a prerequisite to immunotherapy is the reduction of tumour cells in the host's body. Such measures should not be immunosuppressive. Cytotoxic chemotherapy is not appropriate in this regard. Supraradical surgery and non-specific radiotherapy are not desirable for preservation of nervous function, if their immunosuppression is not as severe as cytotoxic substances. Boron-neutron capture therapy is a highly specific and least immunosuppressive means of reducing tumour cells of the central nervous system. A brief introductory review of basic research is presented. The interim clinical results are: (i) Treatment of recurrent glioblastoma: Survival extension obtained by neutron capture therapy is 21.9 +/- 7.2 mos in contrast to that obtained by conventional treatments of 6.7 +/- 0.6 mos (p less than 0.001), (Total survival 26.3 +/- 6.7 mos); and (ii) only three patients including two glioblastoma cases were treated with neutron by the same surgeon who, by performing the first tumour operation, had the advantage in topographic knowledge for determining the radiation field. They survived 4, 5, and 6 years in almost fully active conditions. The new Musashi Institute of Technology Reactor Thermal Neutron Therapy Facility and the increased domestic production of boron-10 isotope have enlarged the therapeutic capacity to two dozen patients a year.

Adolescent↗
PubMed1978

Single neuron analysis of the human midbrain tegmentum. Rostral mecencephalic reticulotomy for pain relief.

Rostral mesencephalic reticulotomy (RMR) has been performed since 1973 for relief of intractable pain. The target area is in the midbrain reticular formation (MRF) bordering the periaqueductal gray matter at the superior collicular level. The target of RMR is 13--16 mm posterior to the midpoint of the AC-PC line and 5--8 mm below the AC-PC line. The laterality of the target is measured from the center of the aqueduct, ranging 5 to 8 mm from the midline. The rationale for this procedure is based upon the previous findings that the brain stem reticular formation plays a more important role above the spinal cord level than the lateral spinothalamic tract in the central conduction of nociceptive impulse. In the present study, intraoperative single neuron recording was made with tungsten microelectrodes from the human midbrain tegmentum in response to peripheral pinprick stimulation. These nociceptive neurons were classified into three groups in regard to the unit latency from the peripheral pinprick stimulation.

Aged↗
PubMed1978

[Differences of behavior of DSCT neurons in decerebrate and barbiturate anesthetized cats (author's transl)].

Responses of dorsal spinocerebellar tract (DSCT) neurons to random electrical stimulation of peripheral nerves of the hindleg in decerebrate cats were studied using cross-correlation analysis of the output spike train. The spontaneous background discharge in barbiturate's cats had longer mean interspike interval than that in decerebrate cats, but there was no difference of the coefficient of variation in the two groups. This suggests that barbiturate has no effect on raising of the electrical threshold of the axon, but prolonging effect on interspike interval. Comparison of the conduction velocity showed to be slower in barbiturate's cats, so barbiturate reduces the conduction rate of the axon. The DSCT responses to the electrical stimulation of peripheral nerve in decerebrate cats were recorded in 60%, while 85% in barbiturate's cats. The reasons for this difference are that the DSCT cells in decerebrate cats are tonically inhibited from the pontine and bulbar reticular formation and the function of brain-stem reticular formation is suppressed by the barbiturate. Type 2 response in decerebrate cats, which represents reduced excitability of the DSCT cells, had inhibition with shorter initial peak latency and duration as compared to that in barbiturate's cats. This confirms the result of Eccles et al. that barbiturate in moderate dosage increases and prolongs the presynaptic inhibition.

Action Potentials↗