Biomedical subjects
Publications and source records attributed to K Sano.
Explore the source record for details and available documents.
In 44 consecutive cases of ruptured cerebral aneurysm, vasospasm was demonstrated pre- or postoperatively. These cases were examined by bilateral carotid angiography and computerized tomography (CT), and the relationship between the angiographically visualized distribution of vasospasm, the neurological symptoms, and infarction seen on CT was evaluated. Vasospasm occurred in only some intracranial portions of the cerbral arteries that were immersed in blood-stained cerebrospinal fluid. Angiographically, diffuse vasospasm extensively involving bilateral carotid systems indicated the gravest prognosis for patients. Vasospasm affecting one carotid system and the anterior cerebral arteries on the opposite side often produced permanent neurological deficits. On the contrary, when vasospasm was restricted to one carotid system or to bilateral anterior cerebral arteries, it was usually associated with temporary neurological symptoms; however, it always produced residual neurological symptoms if it extended to the ascending branches (M3) of the middle cerebral arteries. Computerized tomography definitely demonstrated a low-density area or infarction in the territory of the spastic arteries in 25 (71%) of 35 cases with vasospasm. A low-density area was always detected when vasospasm occurred in M3 segments.
1. Six groups of rats were freely fed diets containing casein at 5, 10 and 20% levels with and without nicotinic acid. After 2 weeks on these diets, hepatic nicotinamide nucleotide and free nicotinic acid concentrations were studied. 2. Hepatic nicotinamide nucleotide level was kept in the normal range in rats fed the 10 and 20% casein diets with and without nicotinic acid. 3. L-leucine supplemented at the 5% level to the 10 and 20% casein diets caused significant decrease in hepatic nicotinamide nucleotide level only in rats fed nicotinic acid devoid diet. 4. Hepatic nicotinamide nucleotide in rats fed the diet in which casein was replaced by zein increased significantly by adding nicotinic acid. This increase in the hepatic nicotinamide nucleotide caused by dietary supplemented nicotinic acid was not reduced by the addition of L-leucine. 5. The hepatic free nicotinic acid level did not change even in rats of which hepatic nicotinamide nucleotide was significantly reduced. 6. Urinary excretion of nicotinic acid and N-methylnicotinamide was increased significantly by adding nicotinic acid to the diet but was not affected by adding L-leucine at the 5% level. 7. From the above results, a possible mechanism of L-leucine action was discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Radiographic quality as well as adverse effects of intrathecal metrizamide instillation was prospectively investigated in thirty-three clinical cases admitted to the department of neurosurgery, University of Tokyo Hospital, and Kantoh Teishin Hospital. Metrizamide CT cisternography was performed in fifteen cases using in most cases 10 ml of 170 mg I/ml solution through lumbar route. Eleven cases exhibited "normal" pattern CSF circulation and the remaining four, "delayed" pattern. Eight cases (53%) experienced headache, nausea, and/or vomiting several hours after the instillation. All of these belong to the "normal" pattern group. Four cases of "normal" pattern received electroencephalographic examinations before and after metrizamide instillation. Three revealed appearance of negative spike and slow wave burst or sharp waves one to twenty-four hours after the instillation, along with penetration of metrizamide into brain parenchyma. Diagnostic quality was interpreted as "good" in eleven cases. Small acoustic neurinoma, pituitary adenoma, arachnoid cyst, and subdural hygroma were diagnosed among others. Metrizamide ventriculography was done in four cases. No untoward effect of significance was attributed to metrizamide per se. Cervical myelograpy and/or CT myelography was done in fourteen cases using, in most cases, 10 ml of metrizamide 170 mgI/ml. Polytome tomography with metrizamide instillation through lateral cervical puncture was highly diagnostic, whereas, ordinary X-ray with lumbar instillation yielded less satisfactory results. CT myelography in cases of subarachnoid block required good consideration on instillation site and positioning of the patient. Six cases (50%) among twelve cases where metrizamide had run into the cranial cavity experienced headache, nausea, and/or vomiting to a lesser degree than those of cisterno graphy. Metrizamide is the first contrast agent ever made which can be safely introduced into human subarachnoid space, if administered judiciously, nervous. However, metrizamide is weakly toxic to central system and provokes minor untoward effects as well as electroencephalographic abnormalities and, sometimes, clinical convulsive seizure. It would be wiser to restrict the dosage of metrizamide in cisternographic study, expecially in cases of "normal" pattern CSF circulation, to 1.2 gI or 7 ml of 170 mg I/ml solution. Routine use of X-ray cisternography should thus be discouraged because it needs higher concentration of metrizamide in the intracranial cisterns.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Pharmacological and biochemical properties of a novel compound, N-(1-benzyl-3-pyrrolidinyl)-5-chloro-2-methoxy-4-methylaminobenzamide (YM-08050) were compared with those of haloperidol (HPD) and chlorpromazine (CPZ) in animals. YM-08050 was more potent than either HPD or CPZ in inhibitory effects on a variety of behaviors such as apomorphine-induced stereotypes behavior and emesis, methamphetamine-induced stereotyped behavior, conditioned avoidance response and open field behavior. YM-08050 induced catalepsy only at much higher doses than to exhibit the inhibitory activities. The inhibitory effects of YM-08050 on [3H]dopamine binding and dopamine-sensitive adenylate cyclase in the synaptic membrane fractions of canine caudate nucleus were much greater than those of HPD and CPZ. The results suggest that YM-08050, a potent central dopaminergic blocker, is a potential antipsychotic drug with less extrapyramidal side effects than those of HPD and CPZ.
Four cases of choroid plexus papilloma (CPP) obtained at the time of surgical excision were examined by light and electron microscopy and compared with normal choroid plexus (CP) of mouse and chick. Ultrastructurally CPPs were the same as CP except in the following two points: In CCPs 1) pinocytotic vesicles of the vascular endothelium and 2) cytoplasmic filaments were more increased in number than in CP. In one case, which showed malignant changes in some parts, we found prominently increased spot desmosomes and cytoplasmic filaments as compared with other three cases, microcysts at the apical portion with other features suggesting the secretory process except for the absence of basal infoldings and myelin bodies. As for the apical tight junction fusion of the two outer-leaflets of the adjacent cytoplasmic membrane was observed as in CP. This fact suggests that there is a blood-CSF barrier also in CPPs as in CP.
Explore the source record for details and available documents.
In spontaneous cerebellar hemorrhage emergency surgical intervention is often life-saving. Clinical features and the operative results of hypertensive cerebellar hemorrhage (18 cases) were compared with those of hemorrhage caused by small angiomas (7 cases). Hypertensive hemorrhage occured most frequently in the seventh decades. Two thirds of the patients developed brainstem compression syndrome within a week from onset. One third remained awake or drowsy throughout their clinical course. Surgical removal of a hematoma was carried out in 13 patients with four deaths. Of note, two comatose patients regained consciousness after surgery, and were discharged with residual ataxia. Rupture of a small angioma occurred in younger patients. Their clinical course was sub-acute or chronic associated with focal cerebellar dysfunction. All seven surgically treated patients subsequently regained independent function. CT findings have been found helpful not only for diagnosis but also in defining appropriate therapy. Hematomas larger than 3 cm in diameter produced signs of rapidly progressing compression of the brainstem. Thereby, regardless of the cause of bleeding, emergency removal of a clot is indicated even in awake patients. Hematomas of 2 to 3 cm produced brainstem compression or prolonged cerebellar dysfunction, and occasionally require surgical decompression. Hematomas smaller than 2 cm can be managed conservatively, since they were absorbed spontaneously in three weeks without residual functional disturbances. However, in case of a young patient exploration should be performed for a probable "cryptic" angioma.
Explore the source record for details and available documents.
The correlation between the changes of regional cerebral blood flow (rCBF) and the histological changes were examined using the middle cerebral arterial (MCA) occlusion model in cats. A total of 24 adult cats were tracheostomized and anesthetized by inhalation of halothane. The right MCA was clipped by the transorbital approach. Two hours after the application, the clip was removed and the brain was recirculated for two hours. Then, the brain was perfusion-fixated and the histological studies were carried out. The animals were separated into two groups according to the severity of histological damages using light and electron microscope. Severe cortical damage was present in 8 cats (Group A). In the remaining 16 cats, little or no cortical damage was found (Group B). The averaged rCBF values before occlusion were 45.4 +/- 2.3 ml/100 gm/min in group A and 46.5 +/- 1.6 in group B, showing no statistically significant difference. Between these two groups, however, there was a statistically significant difference in the averaged rCBF values during the ischemic period. In group A, the averaged rCBF values during MCA occlusion was only 6.8 +/- 0.9 and in group B, it was 25.3 +/- 0.8. In the recirculation period, there was a prompt and uniform recovery of rCBF in group B. Whereas in group A, a marked diversity of rCBF ranging from oligemia to hyperemia ensued. This is presumably a reflection of inhomogeneous blood flow, or patchy non-filling of the cerebral cortex. The critical values of rCBF as to the occurrence of severe cortical damage in two-hours MCA occlusion is considered to lie between the lowest value of group B and the highest value of group A, i.e., around 12--15 ml/100 gm/min.
Many factors are known that contribute to the pathogenesis of the cerebral microcirculatory disturbances, but, there are few reports investigating the roles of the intravascular components directly. The present study was undertaken to evaluate morphological changes of platelets in patients with cerebral damage, in relation to neurological signs, especially consciousness levels. Morphological changes of platelets were observed in 72 patients with intracranial organic lesions. These lesions included subarachnoid hemorrhages, hypertensive cerebral hemorrhages, cerebral infarctions, brain tumors, chronic subdural hematomas, and acute epidural hematomas. Two blood samples were taken, one from the internal jugular vein (the blood after cerebral perfusion), the other from the cubital vein (systemic blood). After fixative procedures with 1% glutaraldehyde, the differences in the three-dimensional structures of platelets were compared, using a scanning electron microscope. In general, remarkably activated forms of platelets were found in the blood after cerebral perfusion in cases with severely impaired consciousness in the acute stage. But, in cases without severe neurological deficits, such changes of platelet forms were rarely seen. A close relationship was suggested between the degree of neurological damage (especially consciousness levels) and that of platelet activation in the acute stage. In the chronic stage, these changes of platelets in the cerebral blood disappeared. Changes of platelet forms were not found in the systemic blood from the cubital vein, even in the acute stage. It is clinically suggested that morphological changes of platelets play an important role in the pathogenesis of the disturbed cerebral microcirculation. Obstruction of cerebral microvasculature may be caused, mechanically by the activated platelets themselves, and/or chemically by vasoconstrictive substances released from these platelets. Therefore, in the treatment of these intracranial organic lesions, it is concluded that the possible roles of activated platelets should be taken into consideration.
Seven cases of coincidental aneurysm with pituitary adenoma found through the review of our personal series of 95 pituitary adenomas over a period of five years are reported. The incidence of coexisting aneurysms in our series of pituitary adenomas (7.4%) was significantly higher than that in other brain tumors (1.1%) (p less than 0.001). Its clinical significance is discussed including the indications for four-vessel angiography, the surgical approaches to these pituitary adenomas, and the management of the associated aneurysms.