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Biomedical subjects

K Moritake

Publications and source records attributed to K Moritake.

At least 127 records · Page 7Linked to original sources
PubMed1980

Computed tomography of cerebral cavernous hemangiomas.

Four cases of histologically verified cerebral cavernous hemangiomas are presented. In one case, computed tomography (CT) showed well demarcated areas of high density, with slight enhancement and no significant mass effect. However, in the other three cases, the CT findings were similar to those encountered in hematomas, low grade gliomas, or meningiomas. Thus, although CT in cerebral cavernomas is informative in most cases, it does not offer specific diagnostic signs.

Adolescent↗
PubMed1980

Venous angiomas of the brain.

Two cases of venous angioma of the brain are presented. Both were discovered by computed tomography and diagnosed by angiography. The lesion was located in the right frontal lobe in 1 case and in the left cerebellar hemisphere in the other. Neither was operated on because of the deep location or extent of the lesion. The 2 cases showed significant angiographic and hemodynamic differences. The literature on venous angiomas of the brain is reviewed. We proposed classifying venous angiomas into two subgroups based on angiographic findings: those with early-appearing vessels and those without. No significant differences in clinical manifestations were noted between these two subgroups in spite of the hemodynamic differences.

Adult↗
PubMed1980

Ultrasonic Doppler assessment of hemodynamics in superficial temporal artery--middle cerebral artery anastomosis.

The pre-, intra-, and postoperative hemodynamics were examined by a newly developed ultrasonic Doppler flowmeter in 20 patients undergoing 24 STA-MCA anastomoses. During the operations, no reverse flow was detected in the cortical branch of the middle cerebral artery. After anastomosis, prominent flow changes in direction and in volume were evident in the cortical branches and the flow pattern of the STA changed from an external carotid type preoperatively to an internal carotid type in well functioning bypasses. The results of postoperative studies were not always in good agreement with those of intraoperative studies and bypass function was relatively not good and labile in patients with only stenotic lesions and in those with "moyamoya disease".

Adolescent↗
PubMed1980

Mechanical properties of human cerebral arteries: Part 2. Vasospasm.

Mechanical properties of human intracranial vertebral arteries subjected to subarachnoid hemorrhage were studied. Their pressure-diameter curves are biphasic and have sharp flexion, called flexion points, at a pressure of 181.3 +/- 9.6 mm. Hg when their smooth muscle is activated by KCl 50 mM. The strong vasoconstriction, accompanied by little change in the vascular diameter, is retained up to the pressure level at the flexion point, above which the constriction is released abruptly. The existence of flexion points at a high pressure level is an important mechanical feature in considering the development and treatment of cerebral ischemia produced by vasospasm.

Biomechanical Phenomena↗
PubMed1979

Mechanical properties of human cerebral arteries. Part 1: Effects of age and vascular smooth muscle activation.

Mechanical properties of the smooth muscle component of human arteries were studied under passive and active conditions. There exists a considerable difference in the development of sclorosis in intracranial and extracranial arteries. Intracranial arteries were already stiff at birth and become stiffer with age. Their increase in stiffness is attributable to the marked thickening of their walls, which compensates for the decrease of their elasticity with age. Intracranial arteries constrict more than extracranial arteries, although the maximum active stress developed is essentially the same. This competency of intracranial arteries for vaso-constriction may be related to cerebral vasospasm.

Adolescent↗
PubMed1978

The role of hemodynamic factors in arterial wall thickening in the rat.

In a study on the pathogenesis of arterial wall thickening, hemodynamic factors in the common carotid artery of the rat were experimentally altered with an autograft. The relationship between flow pattern and wall-thickening was examined in a half-ring bypass model with an induced stenosis, using both flow-visualization in a corresponding in vitro model circuit and observation of the wall by microscopy. Wall-thickening was found in the neighborhood of bifurcations, junctions and curved segments, which corresponded to regions of low-shear in the flow-field. Marked histologic changes in the wall were observed in the post-stenotic segments where the flow field was very disturbed. Histologic changes in the arterial wall correlated well with flow patterns.

Animals↗
PubMed1975

Teratomas in the suprasellar region: report of five cases.

Five cases of suprasellar teratoma are presented. The characteristic clinical symptoms consist of diabetes insipidus, visual distrubance, hypopituitarism, and occasionally increased intracranial pressure accompanied by mild erosion of the sella turcica and separation of cranial sutures. A suprasellar mass lesion was demonstrated in all four cases examined by carotid angiography, and fine vascularization was found in three. Removal of the tumor is the treatment of choice, but if carcinoma, choriocarcinoma, or germinoma tissues are contained in the tumor, irradiation therapy should follow surgical treatment.

Adolescent↗