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Biomedical subjects

M Kabuto

Publications and source records attributed to M Kabuto.

At least 127 records · Page 7Linked to original sources
PubMed1987

Role of the medulla oblongata in plateau-wave development in dogs.

Plateau waves reflect both dilatation of the cerebral vessels and an increase in the cerebral blood volume under increased intracranial pressure (ICP). They are often associated with changes in arterial blood pressure (BP) and respiration, suggesting a role of the brain stem in their development. In experiments conducted on dogs in which intracranial hypertension was induced by occluding the neck veins, the authors stimulated the brain-stem reticular formation in the medulla oblongata and caudal pons to identify the brain sites that produce plateau-like responses. A rise in ICP was observed following stimulation of most areas of the brain stem and was associated with changes in arterial BP, cerebral perfusion pressure (CPP), cerebral blood flow (CBF), respiration, and pulse rate. The stimuli delivered to the medial reticular formation of the caudal medulla caused an arterial depressor response, a decrease in CPP and CBF, suppressed ventilation, and bradycardia; these responses were similar in many respects to plateau waves observed in clinical practice and almost corresponded to the depressor region of the vasomotor center. It is hypothesized that the medullary depressor area may play a role in eliciting cerebral vasomotor reaction concerned with the development of plateau waves in a state of increased ICP.

Animals↗
PubMed1987

Relationship between twenty-four hour urinary creatinine excretion and weight, or weight and height of Japanese children.

Twenty-four hour (24-h) urinary creatinine excretion was measured and correlated with anthropometric measurements (height, weight, skinfold thickness, and arm muscle area (AMA)) in 119 healthy Japanese children, aged 2 to 18 years. The results indicated highly significant correlations between creatinine excretion and age (r = 0.88 for boys, 0.90 for girls), height (r = 0.91, 0.88), weight (r = 0.96, 0.94), and AMA (r = 0.91, 0.70). In the multiple regression estimation, weight alone, or weight and height, accounted for most of the variation in 24-h creatinine excretion (r2 = 0.93 for boys, 0.89 for girls), and the addition of other variables did not further improve the estimation.

Adolescent↗
PubMed1987

[A case of non-neoplastic pineal cyst presenting Parinaud's syndrome].

A case of non-neoplastic pineal cyst with Parinaud's syndrome is presented. A 54-year-old woman was admitted to the department of neurosurgery. Fukui Medical School on October, 1985, complaining of the paralysis of upward gaze. A computed tomography (CT) demonstrated a low density mass in the pineal region and the mass was not enhanced after the injection of contrast agent. Metrizamide CT cisternogram delineated the mass clearly. Bilateral carotid and vertebral angiograms showed no significant findings. On November 5, an operation was performed by means of an occipital transtentorial approach. A cyst filled with clear yellowish fluid was found in the pineal region. The cyst was evacuated and its wall was subtotally resected. The histological examination revealed the cystic cavity lined by fibrous astrocytes which were surrounded by normal pineal tissue. Therefore the cyst was diagnosed as a non-neoplastic pineal cyst. The postoperative course was uneventful. The paralysis of upward gaze was gradually improved. On December 27, the patient was discharged in excellent condition. Non-neoplastic small cysts which do not cause an enlargement of the pineal body are common incidental findings at autopsy, whereas large cysts which cause symptoms due to compression of the corpora quadrigemina and the production of internal hydrocephalus are rare. In this paper, non-neoplastic pineal cyst is discussed.

Brain Diseases↗
PubMed1987

A case of aneurysmal calcification within seventeen years.

A case is reported in which an aneurysm on the anterior communicating artery calcified during the time course of 17 years. A ring-like calcification was demonstrated in plain skull films as well as CT scans. Carotid angiograms showed that the aneurysm grew a little bit bigger for 17 years. The aneurysm was coated because of the calcified aneurysm.

Adult↗
PubMed1986

Lateral sinus pericranii.

Most reported cases of sinus pericranii have been situated near the midline. This report describes a case of laterally situated sinus pericranii and discusses its origin.

Brain Diseases↗
PubMed1986

Treatment of blow-out fracture.

Fifteen patients with blow-out fractures were treated in this series. Two patients were treated conservatively and the thirteen others were treated surgically with the transorbital approach. An infraorbital or medial orbital skin incision was made. The periosteum was dissected and entrapment of orbital fat tissue and muscle were resolved. The floor and/or medial wall were reinforced with tantalum mesh (Codman). The operative results were good in 12 patients and fair in one patient, who retained some diplopia. The tantalum mesh is easy to handle and strong enough to reinforce the orbital wall. It can be seen on plain skull film and makes little artifact on CT scan. This mesh is good material for repairing blow-out fractures.

Adolescent↗
PubMed1986

Nocturnal enhancement of plasma melatonin could be suppressed by benzodiazepines in humans.

Plasma melatonin levels were determined every 20 and 30 min for 24 hours on the last day of repeated oral administrations (1 or 2 mg a day for 8 or 9 days) of a benzodiazepine derivative (450191-s), which is known to be metabolized to active benzodiazepines after administration. In one of the two subjects, the nocturnal enhancement of plasma melatonin which was obvious on a control day with placebo was diminished almost completely. In the other subject, observed were not only the diminishment of its nocturnal enhancement but also its increase during the daytime almost to the nocturnal levels on a control day, which may indicate a rebound increase in melatonin synthesis or a shift in its day-night rhythmicity. Such suppressing effects of benzodiazepines on the nocturnal plasma melatonin levels were also examined in the case of a single administration of 2 mg of 450191-s or flunitrazepam in the second series of experiments. Even a single flunitrazepam seemed to have lowered nocturnal plasma melatonin levels, which then recovered to the usual levels following the administration of 5 mg of a benzodiazepine antagonist, Ro 15-1788, given 6 hours after the flunitrazepam. However, single 450191-s did not show any remarkable effects. Thus, it has been suggested that benzodiazepines could suppress the nocturnal levels of plasma melatonin or shift its day-night rhythmicity at least when administered repeatedly. The possible action site of benzodiazepines may be the central nervous system, since melatonin synthesis has been though to be under strongly regulated by the central nervous pathway from the retina to the pineal body. Therefore, these effects of benzodiazepines may provide a method for investigating the physiological role of melatonin and its day-night rhythmicity as well as to further clarify the system regulating melatonin synthesis in humans.

Adult↗
PubMed1986

Acute endocrine effects of a single administration of methylmercury chloride (MMC) in rats.

The acute effects of methylmercury chloride (MMC) on the endocrine functions were investigated with doses too small to cause any typical neurological dysfunctions. The hormones included PRL, LH, TSH, ACTH, corticosterone (Bk), testosterone (TLI), total thyroxine (T4) and free thyroxine (free T4). The changes in serum hormone levels from 1 hour through 10 days after a single injection of MMC (12 mg/kg s.c.) (Exp. 1), and dose-response relationships between MMC doses (2 to 16 mg/kg s.c.) and the serum hormone levels at 25 hours after MMC injection (Exp. 2) were examined. The acute effects revealed, which were all reversible, are summarized as follows; MMC might directly inhibit thyroxine synthesis; MMC could affect only stimulatively the pituitary-adrenal axis and PRL synthesis/release, the primary action site for which may be the CNS; and the effects of the pituitary-gonadal axis were inconsistent and, therefore, this axis seems to be relatively resistant to MMC. On the other hand, the responses of PRL and TSH to TRH loading, which were examined for both groups in Exp. 3, suggested that MMC could not affect the metabolizing activity for serum PRL and TSH. The hormone levels of the MMC group enhanced by TRH recovered very rapidly as in the control group. Thus, these acute and reversible endocrine effects seem to indicate relatively earlier development of possible chronic and irreversible effects on the endocrine functions when exposed to methylmercury chronically, and these should be examined further.

Adrenal Glands↗
PubMed1986

A case of multiple endocrine adenomatosis type 1.

A case of pituitary adenoma associated with pancreatic islet cell tumor is presented. A 29-year-old man with symptoms of confusion and abnormal behaviour was admitted to the neurosurgical department. He was diagnosed as suffering from multiple endocrine adenomatosis (MEA) type 1. Screening of his family members revealed that his mother had high levels of gastrin, glucagon and parathormone and his father had a high level of gastrin. The pituitary adenoma and pancreatic tumor were removed satisfactorily. Family members as well as the patient should be checked periodically.

Adenoma, Islet Cell↗
PubMed1986

[Cerebral blood flow studies using N-isopropyl I-123 p-iodoamphetamine in cerebral ischemic lesions].

Eighteen patients were studied for cerebral blood perfusion abnormalities using N-isopropyl I-123 p-iodoamphetamine (IMP) and rotating dual gamma camera emission computed tomography (ECT). All were stroke patients, 10 with cerebral vasospasm after an aneurysmal rupture, 3 with an occlusion of the middle cerebral artery, 2 with an occlusion of the internal carotid artery (IC), one with an IC stenosis, one with Moyamoya disease and one with RIND. Four patients had extracranial-intracranial (EC-IC) bypass operations. In three of them, CBF studies were done before and after bypass surgery. An arterial line was placed in the left radial artery and connected to a Harvard pump. IMP (1.5-3 mCi) was injected into an arm vein while at the same time an arterial blood sample was withdrawn at a constant speed for 5 minutes. Scanning was started 35 minutes after IMP injection. After a scan, multiple transverse, coronal and sagittal section images were reconstructed with a minicomputer. We determined the values of regional CBF in the regions of interest using an image. Transmission computed tomography (CT) studies were performed on the same day. In eight patients, CBF study by 133Xe inhalation method (NOVO cerebrograph) was done. ECT showed diffuse low perfusion in two patients and focal low perfusion in 16 patients while CT showed abnormalities in 9 patients (50%). ECT abnormalities were more extensive than CT abnormalities. The values of rCBF in the superficial brain determined by ECT were similar to those examined by the inhalation method (ISI). Significant increase in rCBF was observed after the bypass operations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Amyloid formation in prolactinoma.

Amyloid deposits within a prolactin-secreting pituitary adenoma were investigated with light and electron microscopy. The appearance of amyloid with Congo red revealed amorphous and round green-yellow birefringence under polarized light. Spheroidal concretions disclosed prolactin-positive areas by immunohistochemistry. The amyloid commonly exhibited a structure of fine fibrils of 10 to 13 nm in width, with a hollow core. The fibrils were usually grouped in compact, stout bundles. Some bundles were present in extracellular space, others were obviously within the adenoma cells. Extracellular amyloid fibrils frequently gathered in a stellate arrangement to make a round body. The presence of intracellular amyloid fibrils in adenoma cells may represent that the source of the amyloid is neoplastic cells rather than mesenchymal cells. In addition, prolactin-positive parts in round bodies presumably exemplify that the amyloid fibrils are formed by hormone-relating proteins.

Adenoma↗
PubMed1986

Isotope cisternography in patients with intracranial hypertension.

Cerebrospinal fluid flow (CSF) was studied using isotope cisternography in 52 patients with increased intracranial pressure (ICP), all of whom showed acute transient rises of ICP, i.e., plateau waves, in their continuous ICP recordings. The patients were assigned to two groups. Group I was comprised of 23 patients without hydrocephalus and high ICP resulting from brain tumors, benign intracranial hypertension, and superior sagittal sinus thrombosis. Group II included 29 patients with either communicating hydrocephalus or high ICP resulting from rupture of intracranial aneurysm. Plateau waves were frequently observed in patients with baseline pressures ranging from 21 to 40 mmHg in both groups. The isotope cisternographic pattern in the Group I patients showed a large accumulation of radioactivity over the cerebral convexities, while that in the Group II patients revealed a complete obstruction of the subarachnoid space over both cerebral convexities. The isotope clearance from the intracranial CSF showed a marked delay in both groups of patients with one exception. The results suggest that, in the limited range of increased ICP caused by delayed CSF absorption, plateau waves are most evident regardless of the isotope cisternographic pattern.

Adult↗
PubMed1986

[Cockayne's syndrome presenting cerebral ischemic attack: case report].

A 29-year-old man with Cockayne's syndrome (CS), presenting reversible ischemic neurological deficit is reported. In his past history, hearing disturbance developed at 6 years old and visual disturbance at 12 years old. His parents have consanguinious marriage. He came to our hospital complaining of right-sided hemiparesis and speech disturbance. He was 115.8 cm tall and his weight 20 kg. The characteristic manifestation of CS, i. e., dwarfism, mental retardadation, cachectic feature, retinal atrophy, neural deafness and calcification of bilateral basal ganglia were all noticed. A CT scan on admission revealed marked brain atrophy as well as the intracranial calcifications, while no lesions compatible with his neurological findings were detected. Cerebral ischemic state was mostly suspected. Following up with conservative therapy by the use of fibrinolytic agent, his neurological deteriorations disappeared on the 4th hospital day. Cerebral angiograms showed stenotic lesions of both C1-C2 portion of the left internal carotid artery and the right middle cerebral artery, and the aneurysm in the right internal carotid artery. Such atherosclerotic vascular change as observed in the cerebral angiograms in this case have progressed rapidly for his age. In this case, diabetes mellitus and hyperlipoproteinemia such as increased total cholesterol, increased triglyceride, decreased HDL and increased apoprotein B and C II were complicated for the risk factor of the atherosclerosis. It's controversial that early progress of atherosclerosis is due to ideopathic original feature of CS or to the secondary change from these complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Brain blood volume and blood flow in patients with plateau waves.

Plateau waves, characterized by acute transient rises of the intracranial pressure (ICP), are accompanied by a marked decrease of the cerebral perfusion pressure. Patients with plateau waves, however, often show no clinical symptoms of ischemia of the brain stem, such as vasopressor response or impairment of consciousness during the waves. The authors studied brain blood volume and blood flow with dynamic computerized tomography using rapid-sequence scanning in patients with plateau waves identified during continuous ICP recording. Following an intravenous bolus injection of contrast medium, density-versus-time curves were obtained for the regions of interest; that is, the frontal lobe, the temporal lobe, the caudate nucleus, the putamen, and the pons. The dynamic studies were undertaken when the ICP was high during a plateau-wave phase and when it was low during an interval phase between two plateau waves. The results indicate that, in the cerebral hemisphere (frontal lobe, temporal lobe, caudate nucleus, and putamen), plateau waves were accompanied by an increase in blood volume and, at the same time, a decrease in blood flow. In the pons, however, both the blood volume and blood flow showed little change during plateau waves as compared with the intervals between two plateau waves. These observations may explain why there is no rise in the systemic blood pressure and why patients are often alert during plateau waves.

Adult↗
PubMed1985

[Systemic blood pressure and respiration during plateau wave phenomena].

The intracranial pressure, systemic blood pressure, respiratory pattern and heart rate were studied polygraphically in five patients with plateau waves in continuous intracranial pressure recording. Three brain-tumor patients and two benign intracranial hypertension patients 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. The recordings were made from 18 to 40 hours and a total of 770 plateau waves were examined in this study. The systemic blood pressure showed little or no change in spite of a marked rise in intracranial pressure. The respiratory alterations were always noted during the plateau waves. This respiratory changes during the plateau waves were assigned into three patterns. The first was the suppressed respiratory pattern during the entire course of the plateau waves (Type I): the second was the pattern characterized by the initial suppression followed by the late hyperventilation (Type II); and the third was the hyperventilation pattern during the entire course of the plateau waves (Type III). The pattern of Type I was noticed in 65% of the observed plateau waves, the pattern of Type II in 23%, and the pattern of Type III in 12%. The heart rate decreased in most plateau waves, but there was little change in the heart rate in some plateau waves.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗