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Biomedical subjects

J Suzuki

Publications and source records attributed to J Suzuki.

At least 775 records · Page 43Linked to original sources
PubMed1984

[The interhemispheric trans-lamina terminalis approach to tumor of anterior part of the third ventricle].

In this paper the authors reported the operative approach to third ventricle tumors, mainly discussing bifrontal translamina terminalis approach. Our principle for approaching to the third ventricle tumors is as follows. If the tumor originates from the upper wall behind the Foramen of Monro, transcallosal approach should be adopted. And if the posterior wall is its origin, either transcallosal or infratentorial approach would be better. But if the tumor arises from the anterior half of the third ventricle, translamina terminalis approach should be adopted. In trans-lamina terminalis approach, at first bifrontal craniotomy should be performed. The interhemispheric space of the frontal lobes is dissected and lamina terminalis is cut, then the tumor can be reached. If necessary, the anterior communicating artery can be cut, and/or the optic chiasma can be cut for extending the operative field if the optic nerve is irreversibly damaged. There are several advantages in this approach. First, we can expose the main arteries and the operative filed is wide enough, making the operative procedure safe. Secondly, as comparing to the conventional approaches, any cortical incision or excision is unnecessary. By cutting the lamina terminalis which is usually thin and expanded as a result of hydrocephalus, even a large tumor can be removed. Also lethal complication is avoidable, because this approach has less possibility to damage the lateral wall of the third ventricle. This approach can be applied not only to the tumor but also to AVM or giant aneurysm adjacent to the third ventricle.

Adult↗
PubMed1984

[The effect of prazosin hydrochloride on cerebral vasospasm--an experimental study].

The effect of Prazosin, a new alpha-receptor blocking agent, to release and prevent experimental cerebral vasospasm induced by oxyhemoglobin was investigated. In the first group of cats Prazosin was administered one hour before the induction of vasospasm by oxyhemoglobin, and thirty minutes after the application of oxyhemoglobin in the second group. Doses of 0.5 mg/kg and 0.1 mg/kg were subjected to both groups respectively. In the third group, the divided administration of Prazosin was done; 0.05 mg/kg was given one hour before and two hours after the application of oxyhemoglobin. In the first group, prevention of vasospasm was observed. In the second group, induced vasospasm was released from three hours after the administration of Prazosin. These effects were seemed to be dependent on doses of Prazosin. In the third group, more constant prevention of vasospasm was observed than the former groups. The possible mechanism of preventing and releasing effect of Prazosin on cerebral vasospasm was discussed.

Animals↗
PubMed1984

[A total removal case of cavernous angioma at the lateral wall of the third ventricle with interhemispheric trans-lamina terminalis approach].

A case of cavernous angioma at the lateral wall of the third ventricle which was totally removed with interhemispheric trans-lamina terminalis approach is reported. A 40-year-old male had a slowly progressive onset of partial diabetes insipidus and headache with no neurological deficit . CT scan revealed a high density area at anterior third ventricle. The tumor was diagnosed ectopic pinealoma because of CT findings and clinical symptoms. Irradiation and chemotherapy ( RAFP therapy) was performed to this lesion. After two months, his clinical symptoms disappeared. CT scan showed decrease of the density of the region at this point. He was discharged with no symptom. After a half year, he suddenly complained of right homonymous hemianopsia with headache. CT scan showed that the high density area became larger to left posterior than that of half year before. Left carotid angiogram showed no mass lesion and no abnormal vessel. Operation was performed with interhemispheric trans-lamina terminalis approach using bifrontal craniotomy. Operative findings revealed that the tumor situated at the lateral wall of the third ventricle, had rough surface with reddish colour, and old and fresh blood clots inside the tumor. The tumor was carefully dissected without brain damage and was totally removed. The histological findings was compatible with cavernous angioma. Post-operative CT scan showed no high density area. He was discharged with no neurological deficit without right homonymous hemianopsia. Cavernous angioma of anterior third ventricle is very rare.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Chemiluminescence on hypoxic brain--the 1st report: relation between free radical reaction and energy metabolism].

To explore the possibility that cerebral ischemia or cerebral hypoxia may initiate a series of free radical reactions of brain tissue lipid constituents, we measured sequential change of chemiluminescence and energy metabolites during brain hypoxia in rat. The hypoxic brain was induced by arterial hypoxemia (PaO2 17-22 mmHg) with normocapnia (PaCO2 28-38 mmHg) and normotension (MABP 100-140 mmHg). 4% O2-96% N2 mixed gas was used as the replacement for obtaining lowered PaO2. We made another attempt to analyze chemiluminescence spectra on purpose of luminous mechanism investigation. No peroxidation occurred in prehypoxic state since there were no photon counts, however, chemiluminescence began to rise up in hypoxic state and remained high value in posthypoxic early state. Namely in hypoxic state, 3-min period showed 231 counts/10 sec X g and 5-min period showed 154 counts/10 sec X g. In posthypoxic state, 5-min period showed 217 counts/10 sec X g and 30-min period showed a similar decrease as prehypoxic state. The chemiluminescence spectroanalysis showed five peaks at 480 nm, 520-530 nm, 570 nm, 620-640 nm, 700 nm in wavelength. As to sequential changes of energy metabolism, hypoxia caused marked brain lactic acidosis, increase in ADP, pyruvate and a fall in glucose. However, all metabolites recovered at 30-min period in posthypoxic state, which suggests this was reversible brain hypoxia. A transition of chemiluminescence and energy metabolites suggests the occurrence of free radical reaction in hypoxic and posthypoxic brain. The spectroanalysis reveals the luminous mechanism as follows 1 delta g # 1 delta g----2(3)O(2) + h nu.

Animals↗
PubMed1984

[Sequential changes of vascular intimal ultrastructure in experimental cerebral vasospasm induced by oxyhemoglobin. Scanning electron microscopic study].

Organic changes of vessel wall may play an important role in the pathophysiology of vasospasm after subarachnoid hemorrhage. Sequential changes of intimal ultrastructure in experimental vasospasm induced oxyhemoglobin were investigated by scanning electron microscope. Thirty-four cats were used for this study. The basilar artery was exposed by transcervico-transclival approach. Oxyhemoglobin solution was applied under the arachnoid membrane around the artery in 16 cats at hourly intervals. Of 16 cats, 3 were sacrificed at 1 hour after the first application of the solution, 3 at 3 hours, 3 at 6 hours, 3 at 12 hours, 4 at 24 hours. Three sham-operated cats treated by artificial CSF were used as the control together with 5 untreated normal cats. All procedures were performed under aseptic condition. Perfusion fixation was done. The luminal surface and the cut surface made by freeze-fracture method were investigated by scanning electron microscope. As oxyhemoglobin solution, oxyhemoglobin-rich hemolysate was used and the concentration was 5.5 mM. By hourly application, continuous vasoconstriction of about 70% of the control diameter was obtained. In the control, the endothelial cell layer was flat. The elastic lamina had mild waving, and the luminal surface was smooth. In 1- and 3-hour groups, the elastic lamina was corrugated and the endothelial cells were protruded into the lumen in the depressed portion of corrugation. In 6- and 12-hour groups, degenerative changes of the endothelial cells, crater-formation and ballooning, were seen. Some blood-born cells adhered to the luminal surface in such cases. In 24-hour group, the changes of the endothelial cells became more remarkable.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Nystagmus generated by sinusoidal pitch while rotating.

Sinusoidal pitch while rotating about a vertical axis in darkness causes continuous horizontal compensatory nystagmus in the monkey which persists for the duration of stimulation. The steady-state velocity sums with post-rotatory nystagmus to reduce or cancel it, suggesting involvement of the velocity storage mechanism. Analysis of the labyrinthine excitation during pitch while rotating suggests that the vertical canals play a predominant role in generating the response. Effects of selective labyrinthine lesions are in agreement with this hypothesis. Plugging the lateral canals, leaving the vertical canals intact, blocked the initial rapid response at the onset of rotation, but did not interrupt the continuous nystagmus induced by pitch while rotating. On the other hand, plugging the vertical canals abolished the response. If the lateral canal nerves were cut so that the velocity storage mechanism was inactivated, the continuous response to pitch while rotating also disappeared. The dominant labyrinth activation responsible for the nystagmus during pitching while rotating appears to arise in the vertical semicircular canals and to couple to the oculomotor system through the velocity storage mechanism.

Animals↗
PubMed1983

Local cerebral glucose utilization in epileptic seizures of the mutant El mouse.

The neural pathway and the focus of the epileptic seizure of mutant El mice were studied by the [14C]2-deoxyglucose technique. In the mice with full tonic-clonic seizure, the entire neocortex and hippocampus showed a remarkably increased metabolic rate. By contrast, a lower metabolic rate was evident in the thalamic nuclei, central gray, locus coeruleus and some interstitial nuclei. The epileptic focus in El mice presumably exists in the hippocampus.

Animals↗
PubMed1983

Psychosomatic education in Japan.

In the field of undergraduate education, there are eighty medical schools in Japan but only five of these have independent departments of psychosomatic medicine. Another seventeen schools have a curriculum including psychosomatic medicine. However, oriental psychotherapies such as fasting therapy, Naikan therapy and Morita therapy are taught in only a few schools. The postgraduate education is mainly promoted by the Japanese Psychosomatic Society which has about 1700 members including psychologists, nurses and social workers as well as medical doctors. The society has seven local branches throughout the country which hold one or two educational meetings per year as well as the Annual General Congress. Unfortunately, the growth of the Japanese psychosomatic movement has been fairly static over the last five years. The reasons are varied. Firstly, the Japanese economy has been affected by the recession and the Ministry of Education do not have the funds available to create any new psychosomatic departments in medical schools. The second reason lies with the general medical practitioners who fail to recognise the importance of psychosomatic medicine. In spite of such opposition our executive councillors are working hard to overcome these difficulties.

Curriculum↗
PubMed1983

New embolization method using estrogen: effect of estrogen on microcirculation.

To ascertain the mechanism of action of estrogen administered by a new embolization method, developed by the authors as a treatment method for dural arteriovenous malformations, conjugated estrogens were injected into the mesenteric artery of rabbits, and microcirculatory changes in the dominant areas were studied biomicroscopically. Conjugated estrogen induced sludging and stasis in the microcirculation, approximately in proportion to the concentration and dose.

Animals↗
PubMed1983

Acoustic neurinoma presenting as subarachnoid hemorrhage.

A 49-year-old man who had been suffering from disturbance of hearing for 5 years suddenly developed severe headache, nausea, and vomiting. Computed tomography (CT) scans both with and without contrast medium enhancement, performed on the day of admission, showed a nearly round high-density area in the left cerebellopontine angle. A left transaxillary vertebral angiogram showed no aneurysm or arteriovenous malformation. Hemorrhage from a tumor in the left cerebellopontine angle was suspected. CT scan without contrast medium enhancement, performed on the 17th day after onset, showed only a small, ill-defined high-density area in the cerebellopontine angle. An operation was performed on the 20th day after onset. The tumor was totally extirpated together with a clot. Histologically the tumor was an acoustic neurinoma with hemorrhage and necrosis. The postoperative course was favorable. Massive hemorrhage from primary intracranial tumors, especially acoustic neurinomas, is discussed. Radical operation on the tumor should be performed as soon as possible.

Adult↗
PubMed1983

Mutagenicities of mono-nitrobenzene derivatives in the presence of norharman.

The mutagenicities of 22 mono-nitrobenzene derivatives, i.e., nitrobenzene [98-95-3] and the ortho, meta and para isomers of nitrotoluene [88-72-2, 99-08-1, 99-99-0], nitrophenol [88-75-5, 554-84-7, 100-02-7], nitroanisole [91-23-6, 555-03-3, 100-17-4], nitrochlorobenzene [88-73-3, 121-73-3, 100-00-5], nitrobenzoic acid [552-16-9, 121-92-6, 62-23-7], nitrobenzaldehyde [552-89-6, 99-61-6, 555-16-8] and nitrobenzonitrile [612-24-8, 619-24-9, 619-72-7], were tested with or without S9 mix and norharman [244-63-3] in the Salmonella assay system. None of the compounds was mutagenic without norharman. In the presence of norharman, however, nitrobenzene, nitrotoluene, nitroanisole, nitrochlorobenzene and nitrobenzaldehyde exhibited mutagenicity only to S. typhimurium TA98 with S9 mix. This induction of mutagenesis with norharman was strong for the ortho isomers of every nitro-compound, weak for the para isomers, and was not observed for the meta isomers.

Air Pollutants↗