Search PubMed⌕ Search

Biomedical subjects

M Kabuto

Publications and source records attributed to M Kabuto.

At least 145 records · Page 8Linked to original sources
PubMed1985

[Brain function in patients with plateau waves studied by compressed spectral array in long-term EEG monitoring].

The intracranial pressure, systemic blood pressure and compressed spectral array in EEG monitoring were studied in three patients with typical plateau waves in continuous intracranial pressure recordings. Two patients with brain-tumor and one patient with aqueductal stenosis were included. The intracranial pressure was recorded through an indwelling ventricular catheter attached to a pressure transducer. The systemic blood pressure was recorded through an intraarterial catheter placed in the femoral artery or the dorsalis pedis artery. To obtain continuous and compressed spectral array in the EEG, Berg-Fourier Analyzer by the OET-Biomedica Company of Italy was used. Simultaneous recordings of the intracranial pressure, systemic blood pressure and EEG spectral analysis were made for 180 minutes in each patient. During the plateau waves, the systemic blood pressure did not rise in spite of a marked increase in intracranial pressure, resulting in a marked decrease in the cerebral perfusion pressure. The patients, however, showed no clinical symptoms resulting from ischemia of the brain, such as vasopressor response and impairment of consciousness, but complained only headache. The spectrograms in these patients were characterized by a constant and predominant activity in the alpha or high frequencies. This structural aspect was retained throughout the continuation of plateau waves. The power of low frequencies only appeared transiently. The results suggest that some mechanisms producing and maintaining the fast and/or alpha wave activity may participate in the recurrent appearance of plateau waves.

Adult↗
PubMed1985

[Study of the descending tentorial herniation sign in patients with putamenal hemorrhage at the acute stage].

A sign of descending tentorial herniation (DTH) on computed tomography (CT) in 48 patients with putamenal hemorrhage was examined in the acute stage. Correlation between the DTH sign and prognosis for survival was studied in two groups; a conservative group and an operative group. Patients were grouped according to the presence or absence of DTH sign on CT. Grade 0: no herniation sign; Grade I: an encroachment upon the lateral aspect of the suprasellar cistern (impending herniation); Grade II: widening of the crural and ambient cistern on the same side as hematoma (actual herniation); Grade III: effacement of the cisternal space at the tentorial level (advanced stage of herniation). Twenty-one patients (44%) with Grade 0 DTH sign showed a good prognosis in both conservative and operative groups. Six patients (13%) with Grade I DTH sign also showed a good prognosis in both the conservative and the operative groups except one patient with anisocoria. There were 14 patients (29%) with Grade II DTH sign. Three of them who were treated conservatively showed only mild impairment of consciousness at the initial phase, but became worse 3-4 hours later. In the remaining patients who showed severe impairment of consciousness from the beginning of the illness, prognosis was poor except for patients with hematoma evacuation. Seven patients (15%) with Grade III DTH sign had poor prognosis both in the conservative and the operative groups. It is suggested that, in the acute stage of patients with putamenal hemorrhage, operative procedure should rapidly be performed not only for the clinical herniation sign but also for the DTH sign on CT even if the patients showed no clinical sign and only impairment of consciousness.

Acute Disease↗
PubMed1985

[A case of male prolactinoma presenting extremely high serum prolactin levels and biphasic response to CB-154 suppression test].

A 33-year-old male was admitted to the Department of Neurosurgery, Fukui Medical School with a complaint of headache. There were no neurological deficits on admission. Craniogram demonstrated a so-called "phantom sella". A computed tomography revealed a high density mass lesion and the mass was enhanced well, that mainly extended from the sella to the left middle cranial fossa. The left carotid angiogram revealed an avascular mass lesion extending from the sella to the left middle cranial fossa. Pituitary function tests revealed an extremely high serum prolactin (PRL) levels (70, 100 ng/ml). PRL response to TRH was delayed in peak and the high level continued. Serum PRL levels elevated to 90, 800 ng/ml at 180 min after injection of TRH. A biphasic response was demonstrated in response to CB-154 suppression test to PRL secretion, that is, CB-154 stimulated PRL release initially (up to 90 min) and suppressed thereafter. Serum PRL levels (178, 400 ng/ml) reached to peak about 90 min after CB-154 administration. Response of growth hormone (GH) and adrenocorticotropic hormone (ACTH) to insulin were also impaired. Craniotomy was performed. The tumor was partially removed and was diagnosed as a prolactinoma histologically. Tumor tissue removed was subjected to the monolayer culture and electron microscopic study. Their observations demonstrated hyperactive PRL secretion of the individual cells. A total dose of 5,000 rads was irradiated postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1984

[Note on the mechanism of producing the plateau waves].

Isotope cisternography was performed and ventricular system size was evaluated on serial computerized tomography scans in 57 patients with plateau waves in their continuous intracranial pressure recordings. The patients were assigned to three groups based on the presence or absence of communicating hydrocephalus and their intracranial pressure level: the first group comprised 23 patients with high intracranial pressure and without hydrocephalus, resulting from supratentorial brain tumor, benign intracranial hypertension and superior sagittal sinus thrombosis; the second group included 22 patients with either high intracranial pressure or communicating hydrocephalus, resulting from intracranial aneurysmal rupture: and the third group was composed of 12 patients with normal intracranial pressure and communicating hydrocephalus, resulting from intracranial aneurysmal rupture. Plateau waves in the first group patients were characterized as large plateau like formations recurring at varying intervals, with a height of 50-100 mmHg and a duration of 10 to 30 minutes. Plateau waves in the second group patients had a height of 20 to 60 mmHg and a duration of 3 to 15 minutes. The waves in the second group patients were smaller in amplitude and shorter in duration as compared with the waves in the first group patients. Plateau waves in the third group patients had an amplitude of 15 to 40 mm Hg and a duration of 3 to 10 minutes. They were the smallest in amplitude and the shortest in duration as compared with the plateau waves seen in the first and the second group patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1984

[Trigeminal neuralgia caused by arteriovenous malformation of the cerebellopontine angle--report of two cases].

Two cases of trigeminal neuralgia caused by arteriovenous malformation (AVM) located in cerebellopontine angle (CP angle) are presented. A 61-year-old woman has been suffered from the left 2nd and 3rd division trigeminal neuralgia, and gasserian ganglion rhizotomy did not relieve the pain. Ten days before admission the patient suddenly got right hemiparesis and left cerebellar ataxia. Bleeding of the left CP angle was noticed by computerized tomography (CT) scan and angiogram revealed AVM of the left CP angle. A 48-year-old man had right facial neuralgia for 4 years along and he received percutaneous retrogasserian glycerol rhizotomy twice, but the pain was not aleviated. Superior petrosal sinus was enhanced on conventional CT scan, and air contrast CT cisternography disclosed network shaped structure at the CP angle, which was revealed as AVM by vertebral angiography. The patient was completely relieved from the neuralgia after removal of the AVM. AVM of the CP angle that causes the trigeminal neuralgia is rare and the gasserian ganglion rhizotomy is little effective in aleviating the pain. Bleeding from AVM causes severe neurological deficits. Removal of AVM is important not only for pain relief but also for protecting bleeding. Air contrast CT cisternography is one of the safety and convenient methods to detect the AVM and other vascular anormalies resulting in trigeminal neuralgia.

Cerebellopontine Angle↗
PubMed1977

A radioreceptor assay for insulin: direct measurement of dog pancreatic vein serum insulin.

A simple radioreceptor assay for insulin rat liver membranes as receptor sites, with sufficient specificity precision, and sensitivity to detect 10 ng or 276 muU/ml of serum insulin, has been developed. In the presence of standard porcine insulin at the concentration of 1.0 ng/tube, approximately 8% of 125I-porcine insulin was bound to the plasma membranes and ninety-five per cent of this binding was inhibited by 1.0 microgram of standard insulin per tube. Four animal insulins inhibited the binding of 125I-insulin while ACTH, glucagon, human growth hormone, and oxytocin were inert. Insulin values in dog pancreatic vein sera obtained during and after glucose loading and measured by the present radioreceptor assay agreed well with immunoreactive insulin. The ratio of IRI to the measurement by radioreceptor assay was 1.09 +/- 0.18 for the same sera.

Adrenocorticotropic Hormone↗
PubMed1976

[A trial measurement of individual noise exposure by time-zone in a day (author's transl)].

Noise has been measured usually for a particular source or place and not for each individual exposed. It has been thought to be of great significance if individual noise exposure is recorded in various kinds of noise environment and auditory effects of noise on each individual can be discussed. The present study, having each of examinees carry 10-Channel Noise Exposure Meter with him, intended to know about dose or equivalent sound level (Leq) of individual nois exposure for a whole day and for each of eight time-zones in a day. The examinees were 12 male married workers in a factory manufacturing electronic machines in Kawasaki City, Kanagawa Prefecture, Japan. They were divided into two groups; those who were working in a noisy workshop (Group N, 8 workers) and those who were working in a less noisy workshop (Group N-N 4 workers). Time-zones were categorized as follows: (a) time from rising to leaving home for the place of work, (b) commuting time in the forenoon, (c) working time in the forenoon, (d) noon recess time, (e) working time in the afternoon, (f) commuting time in the afternoon, (g) time from returning home to going to bed, and (h) sleeping time. Leq (c) and Leq (b) were highest and Leq (h) was lowest for Group N among the eight Leq values in the day, while Leq (b) and Leq (f) were highest for Group N-N. Statistically significant differences of Leq for each time-zone between the two groups were found in Leq (c), Leq (d) and Leq (e), whose energy average sound levels for Group N and Group N-N were 84.2 and 59.4 dB, 72.7 and 61.4 dB, and 85.5 and 61.4 dBrespectively. Energy average equivalent sound levels of Leq (24) were 81.0 dB for Group N and 66.7 dB for Group N-N. Leq (24) for Group N were primarily determined by the noise exposure in the working time (c and e), while those for Group N-N by that in the commuting time (b and f). Practical disadvantages in the course of individual application of 10-Channel Noise Exposure Meter were also pointed out. It was shown that it is possible individually to measure the noise exposure dose for each time-zone in a day or daily noise exposure pattern, and the noise exposure dose over 24-hour. It may be recommended that many typical noise exposure patterns and 24-hour noise exposure doses for each of the groups classified by sex, age, kind of job, kind of commuting methods, kind of residential area of residential area and so forth should be surveyed further, which will be useful for estimating the auditory effects of noise on a population. Also, the relationships between Leq and such effects as annoyance or interference with daily activities should be examined to ease the measurement of noise.

Adult↗
PubMedDate not supplied

Inter-population comparisons of catecholamine excretion.

Twenty-four hour urines were obtained from groups of male and female volunteers recruited from urban populations in developed and developing countries (UK, USA, Japan and Nigeria) an from agriculture-based Polynesian population (Tokelau Islands). The urines were collected on typical working days, with minimal disturbance to subjects' normal routines. High-performance liquid chromatography was used to determine catecholamine concentrations in each urine, providing a basis for calculation of total 24-hour excretion. Mean 24-hour excretion of noradrenaline and adrenaline was low in the Polynesians compared to the modern, urban groups, and low in women compared to men. Discussion of the results includes assessment of the possible influences of artefact, physical characteristics of the population samples, physical environment and social and psychological factors.

Age Factors↗
PubMedDate not supplied

Effect of whole-body hyperthermia on the development of peritumoral brain oedema.

The effect of whole-body hyperthermia on the development of peritumoral brain oedema and intracranial pressure was studied in cats with intracerebral transplanted tumour. Whole-body hyperthermia was achieved by means of extracorporeal circulation. The temperature within the brain tumour tissue was increased to 41.8 +/- 0.15 degrees C (mean +/- SD) for 2 h. Measurements of brain water content revealed that hyperthermia worsened the degree of peritumoral brain oedema. Microscopical observation demonstrated that extravasation of horseradish peroxidase, indicating disruption of the blood-brain barrier in the oedematous region, was more severe in animals exposed to hyperthermia than in non-treated animals. Intracranial pressure significantly increased from 13.5 +/- 5.26 mmHg to 25.8 +/- 6.16 mmHg (p < 0.05) during hyperthermia, although it was controlled at 20.7 +/- 2.60 mmHg by continuous infusion of glycerol. The results suggest that whole-body hyperthermia acting on a brain-bearing tumour caused an increase in intracranial pressure due to worsening of the degree of peritumoral vasogenic type of brain oedema. We emphasize that whole-body hyperthermia may be performed with careful monitoring of intracranial pressure for patients who have brain tumour.

Animals↗
PubMedDate not supplied

Production of amyloid beta protein precursor as a proteinase inhibitor by human astrocytic tumors.

The production of amyloid beta protein precursor (APP), which is a potent inhibitor of matrix metalloproteinases and serine proteinases, in human astrocytic tumors (n = 17) and normal brain tissues (n = 3) was investigated. We found proteinase inhibitory activity at around 120 kD by trypsin reverse zymography in the culture media of explant cultures of anaplastic astrocytomas and glioblastomas, but not in those of astrocytomas and normal brain tissues. Immunohistochemistry using a monoclonal antibody against human APP demonstrated that APP was detectable mainly in tumor and endothelial cells. Semiquantative analysis of western blotting revealed that immunoreactivity for APP in the culture media of tumor explant cultures appeared to be increased associated with the malignancy of astrocytic tumors. These findings suggest that APP production may be related to the malignant progression of human astrocytic tumors.

Adult↗
PubMedDate not supplied

An immunohistochemical and ultrastructural study of cultured intracranial hemangiopericytoma.

Surgically excised intracranial hemangiopericytomas from three patients were cultured in vitro and they were examined by immunohistochemistry and electron microscopy to trace the origin of intracranial hemangiopericytomas compared to meningiomas. In all of the three hemangiopericytoma cell cultures, the matrix stained positively for vimentin and desmin. Two stained positive for actin and laminin. Cultured meningioma cells were positive in vimentin staining but negative in others. Hemangiopericytomas continued to have prominent intracytoplasmic intermediate filaments, microfilaments forming dense bodies and pinocytotic vesicles. Reconstruction of only a few cell junctions of zonula adherens type after subcultivation were observed in hemangiopericytoma, while there were neither whorl formations nor cell junctions found, such as desmosomes and junctional complexes, which are common in cultured meningioma cells. These results suggest that intracranial hemangiopericytoma has something in common with muscle cell, endothelial cell and fibroblast which form the vascular and perivascular tissues, and it is distinguishable from meningioma.

Actin Cytoskeleton↗