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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 721 records · Page 40Linked to original sources
PubMed1985

Use of balloon occlusion and substances to protect ischemic brain during resection of posterior fossa AVM. Case report.

The successful resection of a large posterior fossa arteriovenous malformation (AVM) is reported. A balloon catheter was used for temporary intraoperative occlusion of the basilar artery and feeding vessels of the AVM. Prior to occlusion of these arteries, newly tested substances to protect the ischemic brain were administered to prolong occlusion time. Resection of the AVM was completed without complication, and the patient returned to normal life. This is a useful intraoperative procedure for the resection of AVM's considered inoperable by conventional approaches.

Adolescent↗
PubMed1985

[Chemical embolization using estrogen for aneurysmal bone cyst of the skull: case report].

A case of aneurysmal bone cyst of the fronto-parietal bone was reported. The patient was a 48-year-old female with the complaints of conjunctival hyperemia and exophthalmus of the right side. Right selective externography revealed both arteriovenous fistula between right middle meningeal artery and diploic vein, and abnormal venous pooling draining into right superior ophthalmic vein. These symptoms probably caused by the increased intraorbital venous pressure in the right side. Skull plain film and CT scan showed blow-out appearance of right fronto-parietal bone in accordance with the enlargement of diploic space. The bulged area and the rest of the affected part of the bone presented faintly coarse "soap bubble" pattern. And the affected bone, being radiolucent, had well demarcated borders which are distinct and smooth, with faint sclerosis. Both arteriovenous fistula and clinical symptom have disappeared completely by the continuous injection of conjugated estrogen into the right external carotid artery. This is the first case that proved chemical embolization using estrogen will effect a cure in the treatment of aneurysmal bone cyst.

Bone Cysts↗
PubMed1985

[Protective effect of radical scavengers on cerebral infarction--experimental study utilizing the spin trapping method of ESR].

To evaluate the scavenging effect of mannitol, vitamin E and betamethasone in cerebral ischemia, spin trapping technique was applied to the detection of the free radicals generated in ischemic brain homogenate. Thirty Wistar rats were used for this study. In the control group, the brain homogenate prepared immediately after decapitation was preserved at 37 degrees C under N2 gas. Before the preservation and at 30 min, 60 min and 120 min from the start of the preservation, two reaction mixtures containing of spin trapping reagent phenyl-t-butyl nitrone (PBN), NADPH, Fe-EDTA and brain homogenate was prepared from each brain sample--one to be incubated for 20 min at 37 degrees C in air and one to be incubated in nitrogen gas under similar condition. Then the free radical adducts of PBN were measured by electron spin resonance (ESR). In pre-treated group, mannitol, vitamin E and betamethasone were administered intravenously 30 min prior to the decapitation and spin adducts of PBN were detected by same procedures as in control group. The ESR spectra, which hyperfine coupling constants were AN = 16.0-16.6 G and AH beta = 3.0-3.8 G, were obtained from the reaction mixtures in each group. Analyses of their relative intensity in control group revealed that the formation of free radical adducts of PBN was increased dependent on the preservation period under aerobic incubation, and increased gradually for 60 min of preservation time followed by a decrease under anaerobic incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Evaluation of ACNU alone and combined with tegafur as additions to radiotherapy of the treatment of malignant gliomas--a cooperative clinical trial].

Controlled, prospective, randomized studies were performed to evaluate the effects of 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and ACNU plus tegafur as additions to radiotherapy for the treatment of malignant gliomas. In the first trial, 105 patients with glioblastoma or anaplastic astrocytoma were randomly divided into two groups after surgery and received radiotherapy (RT, 40 to 60 Gy to the whole brain), or radiotherapy plus concomitant chemotherapy with ACNU (100 mg/m2 on day 1 and 42). Effects of the treatment were compared in 82 evaluable patients from results of CT scans taken before and one month after the completion of radiotherapy. The regression rates more than 50% of the tumor size were observed in 15.0% of patients treated with RT alone and in 47.6% of patients treated with RT plus ACNU. The difference was statistically significant (p less than 0.005). In the second trial, 87 patients were randomly divided into two groups and received RT plus ACNU, or RT plus combined chemotherapy with ACNU and tegafur (400 mg/m2, daily for 8 weeks). Sixty-nine patients were within the valid study group. The regression rates more than 50% of the tumor size were observed in 34.2% of patients treated with RT plus ACNU: and in 41.2% treated with RT, ACNU plus tegafur. No statistical difference was noted in the response rate between the groups. These results indicate that ACNU is an effective agent in conjunction with radiotherapy for patients with malignant gliomas, and that tegafur does not enhance the effectiveness of ACNU.

Adolescent↗
PubMed1985

[Mitral valvular disease secondary to mitral ring calcification: a clinicopathologic study].

Fifteen cases with mitral valvular disease caused by mitral ring calcification (MRC) were observed among 2,800 consecutive autopsy patients more than 60 years of age. They consisted of one man and 14 women whose average age was 86.4 years. All had been diagnosed as having mitral valvular disease during life. For this clinicopathologic study, the cases were categorized as nine cases with mitral regurgitation (MR Group) and six with mitral stenosis (MS Group). Among the 15 cases, phonocardiograms were obtained in 14 and echocardiograms in 6. In addition, 122 cases with MRC, the length of which was 5 mm or more, were selected from 900 recent consecutive autopsies of senile patients, to evaluate the site of calcification and to analyze the ratio of calcification length to mitral valve ring circumference. The following conclusions were obtained: The prevalence of mitral valvular disease due to MRC in the aged was 15/2,800 (0.5%). MR was observed in nine cases and MS in six. Phonocardiograms of the MR Group revealed a holosystolic murmur in seven cases, a late systolic murmur in one, a third heart sound in four and a fourth heart sound in five. In the MS Group, a holosystolic murmur was found in four, a presystolic murmur in four, a diastolic rumble in one, but no opening snap in any case. A diamond-shaped systolic murmur was found in nine cases with MS or MR, suggesting an ejection systolic murmur caused by an associated calcified aortic valve. Echocardiograms showed markedly decreased DDR in five cases and increased echo intensity of the aortic valve in four. Pathologic findings revealed that the mean length of MRC was 36.6 mm in the MR Group and 58.0 mm in the MS Group. The calcification ring ratio (CRR = MRC/MVR X 100) was 50.3% in the MR Group and 69.8% in the MS Group. In the MR Group, MRC involved the anterolateral commissure in three, posteromedial commissure in five, and both in one. In five of six cases with MS, both commissures were involved by MRC. The study of 122 cases with MRC length greater than or equal to 5 mm suggested that MRC occurred first in the middle scallop of the posterior mitral leaflet, and extended to the posterior scallop, subsequently extending up to the anterior scallop, and finally involved the anterior mitral leaflet beyond the commissures.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1985

[CT-guided stereotaxic evacuation of cerebellar hematoma--lateral approach].

Stereotaxic lateral approach for cerebellar hematoma is presented using Leksell's CT-stereotaxic system. All of the procedures are performed in the CT room. Patient's head is turned to contralateral side of the hematoma 30 to 40 degrees with slight flexion of the neck. Stereotaxic apparatus is secured to the head under local anesthesia. Hematoma is confirmed by computerized tomograms. Three dimensional coordinates of the target point (center of the hematoma) are measured from the vertical and diagonal rods of Leksell's system. Linear skin incision 4 cm in length is made on retromastoid area. Burr-hole is put on just lateral position of the target point, usually 5 to 6 cm posterior and 1 cm above from the external auditory meatus. Transverse or sigmoid sinus does not appeared through the burr-hole by this approach. Specially made Dandy's cannula (3.0 mm in diameter, 220 mm in length) is inserted into the target point, and manual evacuation of the hematoma is performed carefully using a syringe. Then Dandy's cannula is replaced by silastic drainage tube (3.5 mm in diameter), and 6,000 Units of Urokinase solved in 2 ml of saline is administered to the hematoma cavity. Dissolved hematoma is aspirated every 24 hours until the most of the hematoma is evacuated. We operated three cases of cerebellar hematoma by this method with favorable results. Advantages of this method are as follows: Operative invasion is minimal; The surgeon can check the residual hematoma and position of the tip of cannula even at operation, if necessary.

Aged↗
PubMed1985

[A study of the optimum dose of a glucocorticoid, methylprednisolone sodium succinate, before and after neurosurgical major operations--relationship between beta-glucuronidase level and post operative brain edema].

The effects of pre- and postoperative administration of methylprednisolone (5, 10, 15 mg/kg/day) was studied on 50 cases of major neurosurgical operation. The serum level of beta-glucuronidase was also analyzed in 20 cases so as to determine whether it could be useful as an indicator of post operative brain edema. Methylprednisolone seemed to be effective in the cases administrated in the dosage of 10, 15 mg/kg/day. However, several kinds of postoperative infections were seen in the cases administrated 15 mg/kg/day. The results may suggest that the dosage tested, 10 mg/kg/day, causes little side effects while it is clinically effective. The serum level of beta-glucuronidase tended to increase from the second postoperative day to the seventh day. Those increase were remarkably in the cases with brain edema. Recovery of beta-glucuronidase level was earlier in the cases with 10 mg/kg/day administrated rather than in the cases with 5 mg/kg/day administrated. These results suggest that the measurement of serum beta-glucuronidase level may be useful for evaluating the degree of brain edema.

Adolescent↗
PubMed1985

[Chemiluminescence on hypoxic brain--the 2nd report: cerebral protective effect of mannitol, vitamin E and betamethasone].

The effect of vitamin E, betamethasone and mannitol upon a series of pathological free radical reaction within the hypoxic brain tissue was evaluated by chemiluminescence method. The hypoxic brain was induced by arterial hypoxemia (PaO2 17-22 mmHg) with normocapnia (PaCO2 28-38 mm Hg) and normotension (MABP 100-140 mmHg). 4% O2-96% N2 mixed gas was used as the replacement for obtaining lowered PaO2. In the control group high valued chemiluminescence was measured in the hypoxic state and in the early stage of the initial post-hypoxic state. In the groups administered vitamin E, betamethasone, mannitol and combination of them, however, just extra low valued chemiluminescence was detected. Besides to explore the stage on which the drugs act in lipid peroxidation, chemiluminescence spectra was analyzed using the homogenate added the each drug. Intensity peaks of the spectra were around at 480, 520-530, 570, 620-640, 680-700 nm before addition of the drugs. All the intensity peaks diminished after addition of vitamin E and betamethasone, while in case of mannitol, very little decrease of the intensity peaks was revealed. These experimental results indicate as follows. The lowered chemiluminescence value may prove the possibility of vitamin E, betamethasone and mannitol as free radical scavengers or inhibitor of lipid peroxidation. Chemiluminescence spectro-analysis shows that vitamin E and betamethasone act on the break down of lipid hydroperoxide and mannitol act on hydroxy radical in lipid peroxidation.

Animals↗
PubMed1985

[Cerebral angiography following hyperventilation in moyamoya disease--in reference to the "re-build up" phenomenon on EEG].

It is a well known fact that ischemic symptoms are apt to be induced after hyperventilation in child case of Moyamoya disease. We have previously noted that characteristic EEG findings are seen after hyperventilation in this disease. Among these findings, characteristic slow waves which appear after the disappearance or attenuation of ordinary build up have been labelled as "re-build up". Since this phenomenon is highly pathognomonic, we have been evaluating EEG records as an important screening test for childhood Moyamoya disease. Sequential angiograms were taken to understand the nature and pathophysiology of the "re-build up" phenomenon. We now report some interesting findings thought to be related to the particular hemodynamics and pathology of childhood Moyamoya disease. Hyperventilation angiography was performed in 17 patients with Moyamoya disease (7 children, 5 adults whose onset was in childhood and 5 adults). A control study was performed in 5 patients (one child and 4 adults) who were angiographically normal. In each patient, the presence or absence of the "re-build up" phenomenon in the EEG was determined within 1 month prior to the angiographical examination. Angiography was performed prior to 3 minutes of hyperventilation and in the period of "re-build up" under the same conditions with respect to position, site of the catheter tip, volume and the rate of injected contrast media and timing of angiography. In control cases and those cases which did not show "re-build up," angiography was performed 1 minute after termination of hyperventilation. During examination, serial arterial blood sampling was carried out for blood gas analysis. In two cases of Moyamoya disease, hyperventilation under inhalation of 8% CO2 was also performed. In patients with Moyamoya disease who showed the "re-build up" phenomenon, angiographical vascular changes such as decrease in the size of basal Moyamoya and decrease in the diameter of cortical arteries appeared together with "re-building up." These vascular changes are thought to be closely related to the "re-build up" phenomenon. In control cases and adult patients, these findings were not observed. Since these vascular changes did not occur in patients with the "re-build up" phenomenon after hyperventilation of 8% CO2, this phenomenon is thought to be initiated as a direct result of decreased arterial CO2 tension. Although during hyperventilation PaO2 increased, after hyperventilation it decreased significantly while the EEG showed "re-build up".(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1985

[EEG findings in moyamoya disease in children--with special reference to the genesis of re-build up].

EEG findings in Moyamoya diseases in children are characterized by build up during hyperventilation and re-build up after hyperventilation. We examined EEG, tcPO2, tcPCO2 and respiratory curves during and after hyperventilation in 10 cases of typical Moyamoya disease in children. In all of the cases, tcPCO2 decreased gradually by hyperventilation, and its level was about 50% of the pre-hyperventilation level at the end of hyperventilation. It took about five minutes for the tcPCO2 level to return to the pre-hyperventilation level. On the other hand, tcPO2 was increased by hyperventilation. However, it decreased down to 50% of the pre-hyperventilation level within a few minutes after hyperventilation because of the following decrease in the respiratory rate, and it took 5 to 10 minutes to return to the pre-hyperventilation level. Sequential changes in tcPCO2 and tcPO2 showed good correlation with the biphasic change in EEG by hyperventilation in children with Moyamoya disease. The decrease in tcPO2 after hyperventilation seemed in particular to play an important role in the appearance of re-build up. We also examined tcPO2 and tcPO2 during and after hyperventilation in 9 cases of normal children. Sequential changes in tcPCO2, tcPO2 and the respiratory rate were the same as those in children with Moyamoya disease, but re-build up was not observed. In 4 cases of Moyamoya disease we examined the sequential changes in EEG, tcPCO2, tcPO2 and the respiratory rate under the inhalation of 100% O2 and 8% CO2 air.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Effects of cerebral protective agents in experimental cerebral ischemia. Relationship between the degree of ischemia and EEG].

We have previously demonstrated that the preischemic administration of perfluorochemicals (PFC) in combination with 20% mannitol, vitamin E and dexamethasone is effective in protecting the brain from cerebral ischemia. This experimental study was designed to evaluate the effect and limitation of the post-ischemic administration of those 4 agents on cerebral ischemia. We used "Canine model of complete ischemic brain regulated with a perfusion method." Using this model we were able to control the amount of blood flow to the left cerebral hemisphere by using an infusion pump. Infusion blood volume was reduced to 30%, 40% or 50% of the normal state, then the combined treatment was started 1,2,3,4,5 or 6 hours after the onset of ischemia in each ischemic group. By monitoring the EEG for 8 hours of ischemic period, we were able to evaluate the effect of the drugs on cerebral ischemia. In untreated groups, electrical activity deteriorated gradually. In the 30% ischemia group, the EEG became isoelectric within 1 hour following ischemia. In half of the 40% ischemia group, the EEG became isoelectric but in the other half low voltage slow wave were seen to last for 6-8 hours. In the 50% group, the EEG deteriorated gradually but did not disappear within 8 hours. The effectiveness of the treatment was judged by the degree of the recovery of electrical activity. The effectiveness of the treatment appeared to depend on the severity and the duration of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Pharmacokinetics of the new antihypertensive agent nipradilol in rats. 1st communication: Metabolism and disposition after single oral administration of [14C]nipradilol.

The metabolism and disposition of a new antihypertensive and antianginal agent, 3,4-dihydro-8-(2-hydroxy-3-isopropylamino)propoxy- 3-nitroxy-2H-1-benzopyran (nipradilol, K-351) were studied using its [14C]-labelled compound in rats. The plasma level of radioactivity reached the maximum 1 h after oral administration, and the majority of radioactivities administered were recovered in urine and via the bile in feces within 48 h. From the foregoing it is obvious that the drug was absorbed from the gastrointestinal tract rapidly and well, and was eliminated from the body completely. The unchanged drug detected in the plasma and urine after oral administration of 30 mg/kg was more than 10 times as much as that after 3 mg/kg. This fact indicates that the first-pass metabolism of the drug has been saturated. Denitronipradilol, 4- and 5-hydroxynipradilol, and 4- and 5-hydroxydenitronipradilol were identified as major metabolites in the plasma and excreta, and the degradation compounds of the aminohydroxypropoxy side chain were also found as minor metabolites. Among these metabolites, 4-hydroxy metabolites were found mainly as unconjugates and 5-hydroxy metabolites as glucuronides, respectively. These findings suggest that the possible metabolic pathways of nipradilol in rats involve reductive denitration of the nitroxy group, hydroxylation at the benzopyran skeleton, oxidative degradation of the beta-blocking side chain and their glucuronidation.

Administration, Oral↗
PubMed1985

Healing of focal injury in the rat liver.

The healing process of focal hepatic injury produced by thrusting a liquid nitrogen-cooled or fire-heated needle in rat liver was investigated by light and electron microscopy and autoradiography. Twenty-four hours after the injury, necrotic areas were sharply demarcated from the surrounding normal hepatic tissue, and their margin was infiltrated with monocytes, macrophages, neutrophils, and platelets. Following the inflammatory infiltration, Ito cells, cholangiolar cells, and capillary endothelial cells proliferated in the peripheral areas of the necrosis. In accordance with the proliferation of Ito cells, collagen fibers markedly increased. Autoradiography demonstrated that cells proliferating in necrotic areas were predominantly Ito cells, and that hepatocytes adjacent to the damaged sites showed DNA synthesis. Necrotic and fibrotic areas were gradually decreased in size; and by 2 weeks, damaged sites were restored to almost normal histologic appearance, occasional scars remaining. The results of this study indicate that small focal hepatic injury is repaired locally by a mechanism resembling that of wound healing, and that Ito cells play an important role in that process.

Animals↗
PubMed1985

[A case of basal encephalomeningocele (a transethmoidal type) containing the olfactory nerve].

An experience of operative case of basal (transethmoidal type) encephalomeningocele is reported. A 3-year-old boy complained of continuous, spontaneous cerebrospinal fluid rhinorrhea and right intranasal mass lesion. The rhinorrhea began when one year old. He suffered from meningitis at the age of two. When he was three years old, the intranasal mass and CSF rhinorrhea were perceived. On admission he had normal general status and no abnormality in neurological examination. The usual axial computed tomography showed a small mass in the intranasal cavity. But the continuity between the mass and brain parenchyma was not detected in this study. Metrizamide CT cisternography demonstrated it. Coronal CT scan visualized it more directly. We performed operation using bifrontal craniotomy and subfrontal approach. Brain parenchyma did not protrude into the frontal cranial base and expanding right olfactory nerve penetrated into the small defect at the right cribriform plate. The olfactory nerve was extracted as much as possible. The defect was filled with a few piece of muscle and coating with the adhesive agent was performed. Histological findings of operative specimen were abnormal olfactory nerve, normal brain tissue and arachnoid membrane. Post-operative state was uneventful. CSF rhinorrhea disappeared. Post-operative direct sagittal computed tomography visualized the encephalomeningocele extremely. Biopsy of the intranasal mass revealed brain tissue covered by normal nasal epithelium. Basal encephalocele is rare in Japan. We found 10 cases in the literature. It is important that we do not forget basal encephalocele in the difference of intranasal tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1985

[Adult Chiari malformation--five operative cases].

Recently, the diagnosis of adult Chiari malformation seems to have easy, because of the development of high resolution CT. During the last two years, we experienced with five cases of adult Chiari malformation diagnosed by CT metrizamide myelography. There were two males and three females aged from 15 to 55 years. Three cases had both foramen magnum compression and cerebellar symptoms. One of them had lower cranial nerve symptoms too. Another case had central cord symptoms, and the rest of them complained only of headache and vertigo. All cases underwent suboccipital craniectomy and upper cervical laminectomy. After operation, the cerebellar symptoms improved remarkably. Some of the central cord symptoms improved too. In one case with headache and vertigo, the result was unsuccessful. All cases were followed up in the outpatient clinic more than one year after operation. One case unchanged. Another case deteriorated seven months after surgery. The other three cases were in good condition. Operated cases of adult Chiari malformation are relatively rare in Japan. However, this type of malformation can be found easily by CT metrizamide myelography. A good many patients should be operated on carefully in consideration of their symptoms and severities.

Adolescent↗