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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 559 records · Page 31Linked to original sources
PubMed1988

[Protective effect of various agents against ischemic neuronal damage in guinea pig hippocampal neurons studied in vitro].

A study was made of protective effect of several drugs (mannitol, phenytoin, vitamin E and dexamethasone) against the deprivation of both glucose and oxygen from the bathing medium on electrical activities of guinea-pig hippocampal neurons in vitro. Using guinea-pig hippocampal slice, we recorded antidromic field potentials in the granular cell layer of the dentate gyrus with stimulating mossy fibers. "Ischemia" of a slice was achieved by substracting both glucose and oxygen from the perfusing medium. In standard medium, after 10 minutes of ischemia, field potentials had minimum recovery with an amplitude of 5% of control after 60 minutes in the standard medium. Mannitol treatment had no protective effect, but phenytoin, vitamin E and dexamethasone had clear dose-dependent effect. The protective effect was evaluated by recovery of field potential amplitude of the 60 minutes postischemic response and histological examination of the brain slice tissue. The degree of the histological damage was correlated with recovery of field potential. In this experiment we have demonstrated that phenytoin and vitamin E obviously have the protective action against ischemic neuronal damage in the guinea-pig hippocampal slice and the combined application of these drugs were more effective.

Animals↗
PubMed1988

[A case of cavernous angioma extended from the ventral part of the pons to the midbrain: subtemporal and trans-tentorial approach].

The authors presented a surgically treated case of cavernous angioma extending from the ventral part of the pons to the midbrain. A 20-year old man was admitted to our service with left motor weakness, dysarthria and consciousness disturbance. CT scan revealed a round well-circumscribed high density lesion in the pons and midbrain. This was diagnosed preoperatively as a cryptic vascular malformation with hemorrhage. The right temporal craniotomy with keel form skin incision and subtemporal & trans-tentorial approach was performed in an attempt to remove the hematoma and the angioma. Histological examination of the surgical specimen revealed abnormal vessels as a cavernous angioma. The postoperative course was uneventful.

Adult↗
PubMed1988

[The effect of phenytoin on free fatty acid liberation and mononucleotide metabolism in transient ischemia].

Ischemia gives rise to severe energy depletion and influx of Ca from the extracellular space, and it is suggested that increased intracellular Ca leads to the activation of phospholipase C and A, and to liberation of free fatty acids (FFA) in particular arachidonic acid. Phenytoin has been reported not only to maintain the intra- and extracellular cation balance but blockade the Ca channel. The purpose of the present study is to investigate the effect of phenytoin on the liberation of FFA, energy metabolism and mononucleotide metabolism in ischemic brain. Male Wistar rats were subjected to global cerebral ischemia induced by the occlusion of basilar and bilateral common carotid arteries. The brains were frozen in situ by the funnel technique after 5 or 30 min of ischemia or after 10, 30, or 60 min of recirculation following 30 min of ischemia. Purine and pyrimidine nucleotides, FFA, and glycolytic intermediates were measured by HPLC, GLC, and fluoro-enzymatic method. In non-treated rats, ATP reached a nadir after 5 and 30 min of ischemia. Phenytoin significantly attenuated ATP depletion after 5 and 30 min of ischemia. And also E.C. is higher in phenytoin treated rats than in non-treated rats in ischemia. After 60 min of recirculation, ATP recovered to 1.93 +/- 0.02 mumol (72.3% of pre-ischemia) in treated rats but 1.60 +/- 0.07 mumol/g (60% of pre-ischemia) in non treated rats. In E.C., there are significant differences between non-treated and treated rats after 10 and 30 min of recirculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Computed tomographic evaluation due to ruptured intracranial aneurysms in the posterior fossa].

From April, 1978 through December, 1984, computed tomographic (CT) findings were carefully examined in 34 cases of initial subarachnoid bleeding due to a single ruptured aneurysm in the posterior fossa. All of the patients were hospitalized within 3 days of the onset of symptoms. High-density areas, which indicate the presence of subarachnoid clots, were evaluated in the interhemispheric and Sylvian fissures and the interpeduncular, prepontine, ambient, and quadrigeminal cisterns. The CT data suggest that hematomas in the four cisterns are thicker than those in the supratentorial subarachnoid spaces. Only one patient had an intracerebral hematoma. Hydrocephalus accompanied aneurysms of the posterior fossa more frequently than those of the anterior circulation.

Adult↗
PubMed1988

[Correlation of left ventricular outflow obstruction with mitral regurgitation].

Our previous study of mitral regurgitation in obstructive hypertrophic cardiomyopathy suggested that left ventricular outflow obstruction due to systolic anterior motion of the distal residual anterior mitral leaflet may hydrodynamically induce mid-systolic mitral regurgitation. To test this hypothesis, we examined whether drug-induced left ventricular outflow obstruction in dogs might cause mitral regurgitation. Dobutamine, 20-60 micrograms/kg/min, induced the obstruction due to mitral systolic anterior motion with mitral-septal contact in 11 of 18 dogs. Pulsed Doppler and contrast echocardiography demonstrated that mitral regurgitation was concomitantly induced in the 11 dogs. The regurgitation was prominent during mid-systole from the onset to the end of mitral-septal contact. Two-dimensional echocardiography showed reduction of the mitral annular dimension and anterior shifts of the mitral valve coaptation during drug infusion in the 11 dogs. Accordingly, the distal portion of the mitral valve, especially of its anterior leaflet, became residual, and moved anteriorly in early systole and protruded into the outflow tract during mid-systole. Catheter-tip pressure recordings simultaneous with two-dimensional echocardiographic observation revealed that the outflow pressure gradient occurred across the protruding distal residual mitral valve. The onset and the end of the pressure gradient were nearly simultaneous with those of the mitral-septal contact. After cessation of the infusion, the mid-systolic mitral regurgitation disappeared together with the obstruction. These results indicate a close relationship between left ventricular outflow obstruction and mid-systolic mitral regurgitation, and strongly support the hypothesis that the obstruction due to systolic anterior motion of the distal residual anterior mitral leaflet is responsible for mitral regurgitation.

Animals↗
PubMed1988

[Mitral valve prolapse in patients with post-operative atrial septal defect: a preliminary report].

To investigate the clinical significance of mitral valve prolapse (MVP) in patients with atrial septal defect, we investigated 90 patients using various techniques including phonocardiography, mechanocardiography and echocardiography. The examinations were repeated pre- and post-operative periods, and the particular attention was paid on the behavior of the mitral valve motion after surgery. Post-operatively, the incidence of MVP was 56% (50 of 90 patients) compared with the preoperative incidence of 78%. Improvement of MVP was only 24%, and there was no case in which MVP newly developed after surgery. Clinical and laboratory data indicated that the cases with MVP after surgery had larger Qp/Qs, higher pulmonary pressures and larger right ventricular dimension pre-operatively, but had no relationship to the age of surgery and the deformity index of the left ventricle. MVP after surgery was not associated with significant mitral regurgitation.

Adolescent↗
PubMed1988

Transplants and implants for major ear anomalies.

To accomplish two objectives, morphological and functional improvements, in plastic operation of major ear anomalies, the authors presented a surgical method utilizing exclusively auto materials and several pedicles of skin, fascia and periostium. A partially implantable middle ear implantable hearing aid (Partial-MEI) is also an indication to those anomalies. Incidentally, we implanted the first Partial-MEI to a patient with unilateral atresia-microtia. The case was presented and demonstrated Partial-MEI implantation as one of the approaches for major ear anomalies to improve hearing.

Ear, External↗
PubMed1988

[Two cases of spontaneous occlusion of the internal carotid artery due to a giant intracranial internal carotid artery aneurysm].

Although spontaneous thrombosis of a giant intracranial aneurysm is comparatively common, its parent artery occlusion is rare. Recently we experienced two cases in which spontaneous thrombosis of giant intracranial internal carotid artery aneurysm and occlusion of its parent artery were occurred. Case 1. A 49-year-old man, complaining esotropia was referred to us by an ophthalmologist. He had no particular past history. Neurological examination revealed left oculomotor, abducens palsy and disturbance of left trigeminal first branch. CT scan revealed a round high density mass in the left middle fossa. The size was 3 cm in diameter. Left CAG revealed severe stenosis of left internal carotid artery and in delayed phase, faint shadow was seen near posterior clinoid process. MRI revealed a high intensity mass of the intraaneurysmal thrombus in the left middle fossa with small low intensity area indicating residual lumen. With conservative treatment, the symptom was gradually improved and one month after admission, complete occlusion of the left internal carotid artery was seen by angiography. The patient returned to his previous occupation. Case 2. A 21-year-old man was admitted to our hospital complaining dysarthria and left hemiparesis. He had been diagnosed as left internal carotid giant aneurysm 5 years before when he had suffered from right visual disturbance. Neurological examination revealed left hemiparesis and dysarthria. CT scan revealed high density mass which extended from the base of the right middle fossa to the third ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Persistent primitive first cervical intersegmental artery (proatlantal artery II) with occlusion of the basilar artery--a case report].

A rare case of persistent primitive first cervical intersegmental artery (proatlantal artery II) is reported. A 58-year-old man was admitted to our hospital with dysarthria and left hemiparesis. On admission he was stuporous with bilateral gaze palsy and left hemiparesis. CT scan on admission showed low density areas in the right cerebellar hemisphere and ventricular part of the pons. Right retrograde brachiography revealed occlusion of the basilar artery, aplasia of the right vertebral artery and an abnormal vessel connecting the right external carotid artery and the right vertebral artery. This anastomotic vessel was thought to be a persistent primitive first cervical intersegmental artery (Proatlantal artery II). Left carotid angiography revealed the left posterior cerebral artery was visualized through the posterior communicating artery, leading from the internal carotid artery. Left retrograde brachial angiography showed that the left vertebral artery terminated just distal from the branching of the left posterior inferior cerebellar artery. After admission the left hemiparesis deteriorated gradually and tracheotomy was done due to respiratory difficulties. The patient was then transferred to the rehabilitation center on his 34th day in hospital with neurological deficits.

Arterial Occlusive Diseases↗
PubMed1988

[Multiple meningiomas with Werner's syndrome--a case report].

A case of multiple meningiomas with Werner's syndrome is reported. He was 45-year-old man, who complained change of character and slight right motor weakness for 4 months. His symptoms were characteristic small stature, premature senility, scleroderma-like changes and other manifestations. Glucose tolerance test showed a diabetic pattern. CT scan and cerebral angiography revealed multiple meningiomas. After chemical embolization of the feeding artery, we removed these meningiomas successfully. We also reviewed the literature on Werner's syndrome with meningioma.

Humans↗
PubMed1988

[Results of the surgical treatment of multiple aneurysms--review of 372 cases].

The authors review the surgical results in 372 cases of multiple intracranial aneurysms during this 25-year period in which one of the authors (JS) performed 2,000 direct operations for aneurysms. All patients were classified into four groups according to the location of aneurysms as follows: Group 1: multiple aneurysms including anterior communicating artery aneurysm (157 cases); Group 2: multiple aneurysms of unilateral anterior circulation (72 cases); Group 3: multiple aneurysms of bilateral anterior circulation (110 cases); Group 4: multiple aneurysms including vertebrobasilar artery aneurysms (33 cases). In multiple aneurysm cases, their policy has been to treat all aneurysms, ruptured and unruptured, in a one-stage operation whenever possible. About 90% of patients in both Group 1 and Group 2 were treated by one-stage operations, while 60% of patients in Group 3 and 42% of in Group 4 were operated on in the same manner. Excellent and good results in from 73% to 81% of cases was obtained in patients of Group 1, Group 2 and Group 3. Morbidity was 14-19% and mortality was 6-8%. These results were almost equal to the results with a single aneurysm of the anterior circulation. On the other hand, the surgical results in Group 4 were poor with a mortality of 27%. Poor results were attributable to the postoperative rebleeding from the untreated vertebro-basilar aneurysms, which were thought to be unruptured aneurysms preoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1988

[Revascularization of vertebro-basilar occlusive disease].

Various surgical techniques have been reported for vascular reconstruction in cases of vertebro-basilar occlusive disease, but sufficient study has not been made on the question of which technique should be applied in various pathological conditions. Based on our experience, we have examined the advantages and disadvantages of these techniques. In 34 patients with clinically and angiographically diagnosed vertebro-basilar insufficiency, the reconstructive vascular surgery to the posterior circulation was performed. Preoperatively, 24 had vertebro-basilar TIAs, 2 had RIND, 3 had progressing symptoms and 5 had brain stem infarctions verified by persistent deficits. In the 18 patients with intracranial vertebro-basilar occlusive lesions, the bypass were done to the proximal posterior inferior cerebellar artery in 7 cases, proximal superior cerebellar artery in 9 cases, posterior cerebral artery in one and anterior inferior cerebellar artery in one. In the 16 patients with extracranial occlusive lesions of vertebral artery, endarterectomy or subclavian-vertebral transposition was performed. With the exception of one of the progressing stroke cases, in which the surgery was ultimately too late, there were no cases in which neurological symptoms become aggravated following operation. Patency was 94% (32/34). In light of these findings, the following conclusions concerning the operative indication and the selection of the technique have been drawn. In cases with occlusive lesions of basilar artery, the first choice should be bypass to the proximal superior cerebellar artery. In cases with occlusive lesions of vertebral artery, bypass to the posterior inferior cerebellar or superior cerebellar or anterior inferior cerebellar artery should be performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[A successful removal of huge confluence meningioma].

A rare case of huge confluence meningioma with many kinds of venous collaterals is presented. A 58-year-old female was admitted because of severe headache and gait disturbance. An enhanced CT (computerized tomography) scan demonstrated a homogeneous spherical high density mass in the region of the posterior falco-tentorial junction adjacent to the internal occipital crest. Cerebral angiograms showed (1) the occluded confluence sinuum and compensatory venous collaterals, (2) venous drainage through the persistent falcial sinus, which was rare in an adult, from the straight sinus into the superior sagittal sinus (SSS), (3) venous drainage through diploic veins and emissary veins into scalp veins. The tumor including the confluence sinuum was totally removed via a combined bioccipital and suboccipital craniectomy. The confluence sinuum was invaded and occluded by the tumor. The tumor was histologically diagnosed as a fibroblastic meningioma. Post-operative angiogram showed a formation of the new venous channel which is located between the posterior part of the SSS and the lateral part of right transverse sinus. The origin of this new venous pathway was thought to be congenital presence of a "latent" dural venous channel. After ventriculoperitoneal shunting, the patient was discharged without any neurological deficits. A follow-up angiogram one year and two months after discharge showed that the channel become dilated and the venous collaterals seen before surgery disappeared probably due to the change of balance of venous pressure. The venous drainage pattern seemed to become resembling the normal variant type in which the SSS drains into the right transverse sinus, and left sinus was hypoplastic.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Angiography↗