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Biomedical subjects

R Kawai

Publications and source records attributed to R Kawai.

At least 109 records · Page 6Linked to original sources
PubMed1984

Contralateral pterional approach for carotid-ophthalmic aneurysm: usefulness of high resolution metrizamide or blood computed tomographic cisternography.

Four carotid-ophthalmic aneurysms were treated through a contralateral pterional approach. Three of these aneurysms were clipped successfully. Because awareness of the size and shape of the optic chiasm is crucial for the success of this approach, we used metrizamide or blood cisternography with a high resolution computed tomographic scanner. With this technique, the shape of the optic chiasm was delineated before operation to make certain that the prechiasmatic space was large enough for the aneurysm to be approached.

Adult↗
PubMed1983

Digital subtraction angiography and dynamic computed tomography for evaluating the hemodynamics in cases of giant intracranial aneurysm.

Dynamic computed tomography (CT) and digital subtraction angiography were used for postoperative evaluation of the hemodynamic changes in five patients with giant or large intracranial aneurysms. The lesions in four of these cases were giant or large aneurysms of the internal carotid artery, and were treated by occlusion of the cervical internal carotid artery and superficial temporal-middle cerebral artery anastomosis. The lesion in the fifth case was a giant aneurysm of the right vertebral artery, which was treated by proximal clipping of the vertebral artery. Preoperative digital subtraction angiography revealed aneurysmal staining, and dynamic CT scanning indicated the rapid transit of contrast medium in the dome of the aneurysm. Dynamic CT scanning immediately after operation indicated a low flow state in all of the aneurysms, suggesting that they were thrombosed. Although within a few months the peripheral edges of the aneurysms became enhanced, dynamic CT scanning revealed a slower transit of contrast medium through the centers of the aneurysms than in the basilar artery, and digital subtraction angiography failed to demonstrate aneurysmal staining, suggesting that the aneurysms remained thrombosed. The present data indicate that dynamic CT scanning and digital subtraction angiography may be useful for relatively noninvasive evaluation of the hemodynamic changes in patients with giant intracranial aneurysms.

Adult↗
PubMed1983

Metabolic fate of [14C]SM-1652, a new antipseudomonal cephalosporin, after parenteral administration to rats.

A study of the metabolic fate of [14C]SM-1652 after intravenous or intramuscular injection into rats showed that: (i) the elimination of the labeled compound from the blood was the same after intravenous and intramuscular injections; (ii) the radiolabeled drug was distributed rapidly and widely after intravenous administration with the highest concentration in the kidney and the lowest in the brain; (iii) placental transmission was slight, as it was passed into the milk, where the concentration was about 14% that of plasma; (iv) 33 and 67% of the administered radioactivity was excreted in urine and feces, respectively; (v) radioactivity in both urine and bile was ascribable to unaltered SM-1652; and (vi) upon repeated intramuscular injections twice daily, levels of labeled SM-1652 in tissue increased gradually, reaching a plateau at the 11th injection.

Animals↗
PubMed1983

[Angiographic findings of atrophic cerebral disorders in children].

Angiographic findings of the cerebral atrophy in children are discussed. Cerebral angiographies were performed on 20 patients, ranging from 6 months to 16 years of age. Their clinical diagnoses were H-H-E syndrome (4 cases), sequelae of meningoencephalitis (2), sequelae of head trauma (3), infantile spasms (2) and others (9). Final radiological diagnoses of these cases were hemiatrophy (14 cases), generalized atrophy (2) and focal atrophy (4). Circulation time, caliber of arteries, degree of opacification in cortical and deep veins and early filling of deep veins were investigated on angiogram. Slow circulation of cerebral blood flow was shown in 10 cases and normal circulation in 10 cases. Arterial narrowing was observed more frequently in slow circulation group. In cases with hemiatrophy, small caliber of the middle cerebral arteries and slow circulation on the atrophic hemisphere were demonstrated, but no abnormality on the normal side. Deep veins were prominently opacified in cases which showed poor cortical veins, the other way cortical veins were prominent in cases which showed poor visualization of deep veins. Cortical veins and deep veins may compensate each other in cerebral venous drainage. In most cases of slow circulation, dominant opacification of deep veins were visualized and these veins already appeared in arterial phase, but cortical veins had a tendency of poor opacification. These venous drainage patterns are similar to those of Sturge-Weber syndrome. Causes of these vascular changes are unknown. But they may play an important role in cerebral atrophic disorders.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Computed tomographic myelography characteristics of spinal cord atrophy in juvenile muscular atrophy of the upper extremity.

Although atrophy of the lower cervical and upper thoracic cord in juvenile muscular atrophy of distal upper extremity has been reported, the atrophic patterns of the cord, especially in the transverse section, have not been studied extensively. The aim of this study is to clarify the atrophic patterns of the cord by CT myelography (CTM) and to discuss the pathogenesis of cord atrophy. Sixteen patients with juvenile muscular atrophy of distal upper extremity were examined by CTM. Atrophy of the lower cervical and upper thoracic cord, consistent with the segmental weakness, was seen in all patients. Flattening of the ventral convexity was a characteristic atrophic pattern of the cord. Bilateral cord atrophy was commonly observed; eight of 12 patients with unilateral clinical form and all four patients with bilateral form showed bilateral cord atrophy with dominance on the clinical side. There was no correlation between the degree of cord atrophy and duration of symptoms. Flattening of the ventral convexity, associated with purely motor disturbances, reflects selective atrophy of the anterior horns in the cord, which is attributable to chronic ischemia. Cord atrophy proved to precede clinical manifestations. The characteristic atrophy of the cord provides useful information to confirm the diagnosis without long-term observation.

Adolescent↗
PubMedDate not supplied

Histologic examination of dislocated lenses.

PURPOSE: To examine histological changes resulting from dislocated and subluxated lenses. CASES: The subjects consisted of 16 patients (aged 52-89 years) who underwent total lens extraction for lens dislocation or subluxation in the Department of Ophthalmology at Fukui Medical University during the period between April 1991 and June 1998. There were 5 patients (6 eyes) with traumatic dislocation and 11 patients (11 eyes) with idiopathic dislocation. RESULT: Rupture of the cortical fibers and migration of the epithelial cells toward the posterior pole of the lens were more frequently noted in patients with traumatic dislocation than in the idiopathic group, and both findings were often simultaneously observed. Rupture of the cortical fibers was considered attributable to external pressure transmitted to the lens. CONCLUSION: We speculate that the concurrent migration and dislocation of the equatorial bow architecture toward the posterior pole was caused by inhibition of differentiation of the epithelial cells to fiber cells by external pressure on the equatorial region.

Aged↗