Search PubMed⌕ Search

Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 667 records · Page 37Linked to original sources

Metabolism of nipradilol by liver homogenates from different species. I. Comparative studies on the denitration of nipradilol and other organic nitrates.

Nipradilol (NP) was metabolized mainly in liver and denitrated and/or hydroxylated metabolites were formed. NP was not metabolized in heart or lung, and was stable in blood. Denitration of NP was catalysed mainly by glutathione-dependent organic nitrate reductase in liver cytosol, and the hydroxylation was catalysed by liver-microsomal enzymes. Denitration activity for NP was far lower than that for nitroglycerol and isosorbide dinitrate with liver homogenates of several animal species. A marked species difference was found in the denitration activity for NP; dog liver was especially low compared with rabbit, rat and mouse liver.

Adrenergic alpha-Antagonists↗

Bifrontal interhemispheric approach to aneurysms of the anterior communicating artery.

The authors review their experience with the bifrontal interhemispheric approach in 603 cases of single anterior communicating artery (ACoA) aneurysms and describe the operative technique. With this approach, the olfactory tracts are dissected, and both A1 segments of the anterior cerebral arteries are identified subfrontally. The interhemispheric fissure is then dissected and A2 segments are followed from the distal portion toward the ACoA complex. Following the administration of a combination of mannitol, vitamin E, and dexamethasone, a temporary clip is placed on at least the dominant A1 segment prior to dissection of the aneurysm itself. Once the aneurysm has been completely freed from the surrounding structures, the neck is ligated and clipped. If the aneurysm ruptures during surgery, temporary clips are placed on both A1 and A2 segments bilaterally and the operation proceeds in a completely dry field. With this method, it is possible to occlude any of the intracranial vessels for up to 40 minutes within 100 minutes of drug administration. To prevent the possibility of rerupture and the development of vasospasm in the period before aneurysm surgery, the authors have adopted a policy of performing ultra-early operations within 48 hours of the onset of symptoms. Among the 257 cases operated on during the 9 years since 1975, one-fifth have been operated on within 48 hours of rupture, and the in-hospital mortality rate has been only 4.3% (11 cases). Follow-up studies have shown that 87% of the 246 surviving patients have returned to useful lives.

Humans↗

Clinical course of acute middle cerebral artery occlusion.

Knowledge of the natural course of stroke patients has become increasingly important since new therapeutic methods have been proposed for patients with cerebral infarction in the acute stage. In order to clarify the acute stage of this disease, 188 patients admitted within 24 hours after onset of middle cerebral artery (MCA) occlusion were followed for 2 months, and data relating to mortality and changes in disturbances of consciousness and motor function were investigated. It was shown that the prognosis for MCA occlusion cases is poor, and about 80% of these patients are unable to return to their previous lifestyle. The level of consciousness in the acute stage is a good index for estimating the patients' quality and time of survival, and motor function in the acute stage is a good indicator of functional recovery. Thus, when evaluating the effectiveness of a new therapy for cerebral infarction, rapid improvement in the acute stage before and after treatment should be carefully noted.

Adult↗

Early cerebral angiography after aneurysm rupture. Analysis of 197 cases.

Although many patients with aneurysm rupture have undergone re-rupture during angiography, this event seldom occurs in the early period after the original hemorrhage. The authors review 197 cases of ruptured cerebral aneurysms that had received cerebral angiography within 1 week of rupture. With the exception of one case of re-rupture during angiography, no complications were noted in any of the patients. The criteria used for early cerebral angiography after aneurysm rupture are described.

Cerebral Angiography↗

[Clinical studies of cefoperazone in neurosurgery].

A multicenter trial consisting of 164 institutions through out Japan, has been conducted to study the transfer of cefoperazone (CPZ) into the cerebrospinal fluid (CSF), and the clinical effectiveness of CPZ as a therapeutic or prophylactic agent in neurosurgery. The levels of CPZ in serum and CSF were determined in 96 patients. After initial dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum level of CPZ after 1 hour was 124.5 +/- 6.6 micrograms/ml (Mean +/- S.E.), and even after 6 hours, it maintained as high as 47.8 +/- 16.6 micrograms/ml. The peak CPZ levels in CSF in patients with normal or minimal impairment in blood-CSF-barrier (BCB) (group I) and in those of localized impairment in BCB (group II) were 1.0 +/- 0.5 micrograms/ml at 2 hours and 3.0 +/- 1.8 micrograms/ml at 3 hours, respectively. The highest CSF level was seen in patients with meningitis (group III) and showed 5.0 +/- 2.4 micrograms/ml at 6 hours. After multiple dose of 2 g CPZ (intravenous drip infusion for 30 minutes), the serum kinetics of CPZ were not significantly different from those obtained after initial dose. However, the CPZ levels in CSF were higher than those observed after initial dose in all 3 groups and were higher than MIC75 against relevant pathogens for meningitis such as Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. Moreover, in group III peak level of CPZ in CSF exceeded the MIC75 against Pseudomonas aeruginosa which is also frequently isolated from patients with meningitis in neurosurgery. As a therapeutic agent CPZ administered as sole agent was effective in 42 out of 55 cases (76.4%) in meningitis, in 78 out of 116 cases (67.2%) in pneumonia and in 36 out of 47 cases (76.6%) in urinary tract infection (UTI). Its efficacy rate against all infections treated was 72.2% (184/255). Regarding CPZ's prophylactic use, 39 out of 514 cases (7.6%) were judged as having or possibly having infections as follows; meningitis (13/514, 2.5%), pneumonia (15/514, 2.9%), UTI (2/514, 0.4%). In prophylactic use of CPZ, the incidence rates of postoperative meningitis and other central nervous system (CNS) infection following ventricular drainage and supratentorial craniotomy for aneurysm were higher than those observed in other types of operation, 12.0% (3/25) and 6.2% (8/130), respectively. Also, regarding prophylactic use of CPZ, the organisms isolated by culture from 13 cases of postoperative CNS infections included 2 strains of Staphylococcus sp., 1 strain of Serratia sp. and 3 strains of other Gram-negative bacteria (GNB).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

[Superior protective activity of phenytoin against hypoxia in pharmacological screening test].

In the treatment of cerebral infarction, it is important to select drugs for inhibiting development of the pathology. In order to select markedly effective drugs among many drugs, it is possible to grasp the outline of drug effects by means of an experimental system with simplicity and regularity--a screening test. In the present study, we induced a hypoxic load by exposing mice to a gas mixture consisting of 4% O2 and 96% N2, and investigated the effects of various kinds of drugs with reference to the survival time(ST: mean +/- SE), the time until the respiratory arrest of the mice. In the control group (n = 110), ST was 170 +/- 6 sec, with a normal distribution, and no mice that survived for eight minutes or more after the load were found. In contrast, ST was 1,833 +/- 487 sec in the suloctidil-treated group (12.5 mg/kg, n = 11), 1,160 +/- 342 sec in the vitamin E group (200 mg/kg, n = 15), 602 +/- 74 sec in the pentobarbital group (50 mg/kg, n = 12) and 2667 +/- 452 sec in the phenytoin group (100 mg/kg, n = 10). On the other hand, no prolongation of ST was found in the groups to which vitamin C, coenzyme Q, cytochrome c, betamethasone, mannitol or germanium-132 were administered. The ratio of the mice that survived for one hour or more after the load was 0% in the control group, 45.5% in the suloctidil group (12.5 mg/kg), 23.5% in the vitamin E group (200 mg/kg), 0% in the pentobarbital group (50 mg/kg) and 70% in the phenytoin group (100 mg/kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Detection of free radicals generated in NADPH-dependent lipid peroxidation in ischemic brain homogenates--use of the spin trapping technic].

Spin trapping technique has been applied to the detection of free radicals generated in NADPH stimulated lipid peroxidation process in ischemic brain homogenate. Using male Wistar rats, complete cerebral ischemia for 30 min, 60 min or 120 min was produced by decapitation followed by preservation of the heads at 37 degrees C. Global cerebral ischemia of 30 min or 60 min duration was induced by occlusions of three vessels (bilateral common carotid and basilar artery) in the ventilated rats. In some animals, bilateral carotid occlusions were released for 30 min following 30 min of ischemia to study postischemic event. Two reaction mixtures containing of brain homogenate, NADPH, Fe-EDTA and spin trapping reagent, phenyl-t-buthylnitrone (PBN), were prepared from each brain sample--one to be incubated in air and the other to be incubated in nitrogen gas. After the incubation for 20 min at 37 degrees C, free radical adducts of PBN were measured by electron spin resonance (ESR). In preliminary experiments, no ESR signals were obtained from the reaction mixtures without the addition of NADPH and Fe-EDTA. And the dependence of ESR signal intensity upon the NADPH concentration was observed. The six-line signals (triplet of doublets), which hyperfine splitting constants were AN = 16.2-16.5 G and A beta H = 3.6-3.8 G, were obtained from both ischemic models. These signals were dependent upon the presence of oxygen in the reaction systems, as evidenced by the fact that the signal intensity obtained from aerobic incubation was consistently stronger than that obtained from anaerobic incubation in each brain sample.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[A case of massive fatal hemorrhage in a recurrent medulloblastoma during radiotherapy].

A medulloblastoma in a 7-year-old girl showed complete remission after the initial radiotherapy of 5,000 rad. But she had three episodes of recurrence in the cerebellum and in the spinal cord, and was treated by additional radiotherapy for the lesions 3,000 to 5,000 rad. When the total cerebellar tumor dose became 13,300 rad, a fatal intratumoral hemorrhage occurred. Autopsy revealed a massive intratumoral hematoma and thin-walled tumor vessels which might be designated as "sinusoid" or "telangiectasia" microscopically. The authors proposed a possibility that the thin-walled vessels and the high dose of radiotherapy caused the hemorrhage.

Cerebellar Neoplasms↗

[Surgical treatment of AVMs occluding these feeders during removal--utilizing the intraoperative balloon catheter and brain protective substances ("Sendai cocktail"].

The ideal treatment of cerebral arteriovenous malformations (AVMs) is thought to be the total resection of nidus. We have been reporting the importance of temporary occlusion of the feeding arteries with the aid of the brain protective substances to prolong the permissible time of occluding these arteries. Because of the difficulty of access to the feeding arteries, some cases are difficult or even impossible to operate. In this communication, four cases of AVM which were successfully resected utilizing intraoperative balloon occlusion of feeders under the administration of the brain protective substances are reported. Case 1. A 14-year-old female was admitted to our clinic because of subarachnoid hemorrhage with ventricular rupture and left cerebellar hemorrhage. Angiography disclosed a large left cerebellopontine angle AVM fed by left anterior inferior cerebellar artery (AICA) and left superior cerebellar arteries (SCAs). Prior to the operation, two balloon catheters were introduced via transfemoral approach; one into the AICA and the other into the basilar artery where left SCAs originated. To prolong the permissible time of occluding these arteries, "Sendai cocktail" (20% mannitol, vitamin E and dexamethazone) and perfluorochemicals were administered. Auditory brain stem response (ABR) was monitored continuously during the operation. The nidus was resected totally with safe using temporary inflation of these balloon catheters. The patient returned to normal life. Case 2. A 35-year-old male was admitted to our clinic complaining of the attack of generalized convulsive seizure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[A successfully treated case of giant basilar artery aneurysm utilizing balloon catheter occlusion and brain protective substances].

A case of giant basilar artery aneurysm successfully treated utilizing balloon catheter under the administration of 20% mannitol, dexamethasone, vitamin E (Sendai Cocktail) is reported. The patient, 59 years old female, was admitted to our clinic with complaints of headache. CT scan revealed partially enhanced, round-shaped high density mass with a diameter of 35 mm in the left posterior part of the basal cistern. Vertebral angiography revealed aneurysm at the junction of left posterior cerebral artery and superior cerebellar artery. These findings indicate the partially thrombosed giant basilar artery aneurysm. Direct operation was performed just after the inflation of balloon within the aneurysm which made temporary occlusion of the aneurysm to make the operation safely. After removal of some amount of thrombosed aneurysm, temporary clips were applied on the basilar and bilateral posterior cerebral arteries, and then the neck of aneurysm was clipped. The combined use of the balloon, Sendai cocktail and temporary clips were recommended in such a case.

Aneurysm↗

[Protective effect of phenytoin and its enhanced action by combined administration of mannitol and vitamin E in cerebral ischemia].

Phenytoin is well known as the anticonvulsant agent and also said to protect the brain against ischemic damage. The purpose of the present experiment is to study the therapeutic effect of phenytoin on cerebral ischemia and confirm whether the effectiveness of phenytoin could be enhanced by combination of free radical scavengers such as mannitol and vitamin E. In this experiment, twenty-five dogs were subjected to ischemia, using the "canine model of complete ischemic brain regulated with a perfusion method" in which it is possible to control the degree of blood flow to a cerebral hemisphere via a perfusion pump at will. Five animals served as untreated control, fifteen received treatment with phenytoin (7 mg/kg in five dogs, 10 mg/kg in five dogs and 30 mg/kg in five dogs) and five treated with 10 mg/kg phenytoin, 2 g/kg of mannitol and 30 mg/kg of vitamin E. These drugs were administered intravenously 20 minutes prior to the production of ischemia, when cerebral blood flow was reduced to one-tenth its normal volume. After one hour, cerebral blood flow was restored and the recovery of electrical activity of the brain and the degree of brain swelling were observed for three hours. With regard to the recovery of EEG, no recovery of EEG was seen subsequent to recirculation except one dog in the control group. Whereas in the group treated with phenytoin, gradual emergence of slow wave ws observed soon after recirculation. The higher the administered dosage is, the better the degree of recovery of EEG was seen. Thus, the dose-related recovery of EEG was observed within the dose ranges tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[A case of adult respiratory distress syndrome (ARDS) induced by radio-chemotherapy (RAFP therapy) of brain metastasis of stomach cancer].

A 77-year-old male was admitted to the hospital because of left hemiparesis secondary to multifocal cerebral metastases from adenocarcinoma of the stomach. He was treated with combination of radiotherapy and chemotherapy consisting of ACNU, Tegafur and PSK. He was in good condition, but abruptly developed severe dyspnea 40 days after administration of Tegafur and 28 days after that of ACNU. Chest X-ray at that time revealed diffuse opacity involving entire lung fields associated with marked hypoxia. The patient expired 9 days after this episode. The autopsy revealed acute interstitial pneumonitis associated with hyaline membrane formation consistent with adult respiratory distress syndrome involving entire lobes of both lungs without metastases. As to the etiology of the ARDS in this case, we concluded that the administration of Tegafur was the most likely as to the cause, although the possibility of betamethasone was not ruled out. The remaining factors were not likely as to the cause of the ARDS in this case.

Adenocarcinoma↗

[CT-guided stereotaxic implantation of a deep brain electrode for the stimulation of the internal capsule--a case report].

A 47-year-old man was admitted to our clinic because of the pain of left extremities for four years. The patient developed dysesthesia, hyperpathia and spontaneous pain 2 months after the onset of cerebrovascular accident with left hemiparesis. Using Toshiba TCT-20A CT scanner and Leksell's CT-stereotaxic system, stimulation electrode (by Medtronic Co.) was implanted in the posterior limb of the internal capsule which was 25 mm lateral to the posterior commissure. Ventriculography was not necessary because the target point was directly measured from the axial CT and midsagittal reformatted CT based on 18 axial CT images (2 mm thick slices). Anterior commissure, pineal calcification, posterior commissure and Sylvian aqueduct were demonstrated on the midsagittal reformatted CT by this method. The pain was relieved by the ramped square pulse stimulation (2 V, 0.6 msec, 50 Hz) and receivor system was internalized. The patient was free from pain by 30 minutes-long stimulation four to six times a day. Precise electrode placement was possible by CT images alone using high resolution CT and CT-stereotaxic system. CT-guided stereotaxic technique seemed to have an advantages especially for the implantation of electrode in the posterior limb of the internal capsule. The reason is as follows: The target is just lateral to the posterior commissure which could be recognized easily on the midsagittal reformatted CT. The internal capsule is advantageously demonstrated on the axial CT.

Brain↗

Clinical significance of early or mid-systolic apical murmurs: analysis by phonocardiography, two-dimensional echocardiography and pulsed Doppler echocardiography.

The records of 2,000 consecutive patients who had been examined by auscultation, phonocardiography (PCG), two-dimensional echocardiography and pulsed Doppler echocardiography (PDE) were reviewed to assess the clinical significance of apical systolic murmurs which cease well before the aortic closure sound. Fifty-five patients were verified to have early or mid-systolic apical murmurs. Mitral regurgitation (MR) was detected in 32 patients by PDE (29/32) and/or PCG with methoxamine test (27/32). The degree of MR was judged to be mild by PDE in all cases. Apical systolic murmurs due to MR began mainly with the first heart sound (27/32), were confined to the apex (27/32), and high-pitched (25/32). Their intensity was grade III/VI or less in all cases. Mitral valve prolapse (12 patients) was the most common cause of MR. Other causes were rheumatic mitral involvement in seven patients, dilated or ischemic cardiomyopathy in five, mitral annular calcification in three, and hypertrophic cardiomyopathy in two. The causes of the MR in the remaining three patients could not be identified. Thus, early or mid-systolic apical murmurs are mainly attributable to mild MR which can be diagnosed by careful auscultation, PDE and/or PCG with the methoxamine test.

Adult↗

[Musical murmurs: phonocardiographic, echocardiographic and Doppler echocardiographic study].

Musical murmurs are probably related to the vibrations of some structures in the cardiovascular system, and this may be reflected in the characteristic stripes which are recorded by the fast Fourier transformation (FFT) of the pulsed Doppler echocardiography (so-called FFT stripe). In the present study, we demonstrated new stripes by color Doppler echocardiography, which were composed of multiple warm and cold color bands which we termed color Doppler stripes (CD stripe). An experiment was performed to obtain Doppler signals from the surface of a vibrating tonometer at a frequency of 128 Hz. When the CD stripe was obtained, a similar FFT stripe was also recorded from the same sampling site. Fourteen patients with musical murmurs were selected from 2,000 consecutive phonocardiographic records made during the last one and a half years. The CD stripe was obtained in three and the FFT stripe in six. When both stripes were obtained, the FFT stripe was always obtained if we set carefully the sample site in the CD stripe, and these two were consistent in timing. We concluded that, in view of the close correlation between the CD stripe and the FFT stripe, the newly observed CD stripe is also a characteristic finding reflecting a regularly vibrating structure. The technical feasibility of color Doppler echocardiography to detect fine movements of structures may be helpful in the study of musical murmurs.

Adult↗

[Association of anorexia nervosa and mitral valve prolapse].

Four cases of anorexia nervosa recently encountered were reported in respect to their cardiovascular manifestations including prolapse of the cardiac valves and other poorly recognized cardiac findings. All four patients, aged 13 to 32 years, were women and had marked emaciation (35 to 44% weight loss of the ideal body weight) with typical hormone abnormalities. Chest radiographs showed a small cardiac shadow, and sinus bradycardia with low voltage was present in their electrocardiograms. One case, 13-year-old, had a mid-systolic click and occasionally a late systolic murmur, and also an abdominal continuous hum. Echocardiography including two-dimensional color flow-mapping disclosed mitral valve prolapse in all, and tricuspid valve prolapse in two. Mild to moderate pericardial effusion was noted in all between the right ventricle and diaphragm, and pericardiocentesis in one case had no effect on the valve movements. No inflammatory changes were observed in the specimen of the pericardium and also of the fluid. An association of mitral valve prolapse and anerexia nervosa was discussed based on the previous studies, but the final conclusion remains unknown.

Adolescent↗