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Biomedical subjects

M Toyama

Publications and source records attributed to M Toyama.

At least 109 records · Page 6Linked to original sources

[CT findings of skull and intracranial metastatic neuroblastoma--report of 3 cases (author's transl)].

Three cases of neuroblastoma with intracranial metastases were reported. The first case was a 13-year-old girl with sacral neuroblastoma who had metastases to the left parietal bone and dura, and had bilateral intraorbital metastases. The second case was a 13-year-old girl with mediastinal neuroblastoma who had bilateral intraorbital metastases. The third case was a 49-year-old woman with esthesioneuroblastoma which had invaded to the dura at the right middle fossa and the right orbit. CT findings of the brain of these three cases were investigated, and summarized as follows: 1) The intracranial invasions of the metastatic tumors were seen to be slightly high density (EMI-number 25-27) in plain scans, and homogeneously enhanced as a well-defined high density mass (EMI-number 35-37). 2) The tumors invading the skull were observed as a mass lesion of the bone on osteolytic lesion. 3) The intraorbital metastatic tumors were seated on the orbital wall invading the rectal muscles, but they remained extraconal. It was emphasized that CT could give valuable information for the diagnosis of skull and intracranial metastasis of neuroblastoma.

Adolescent↗

Increased concentration and accelerated synaptosomal uptake of noradrenaline in the central nervous tissues of neonatally hemispherectomized adult rats.

Neonatally hemispherectomized adult rat brain was analyzed. The content of noradrenaline (NA) had increased significantly in the brain stem (+ 116%) and the cerebellum (+ 100%) by the 3rd month after operation. The Km for the high affinity uptake of NA by the brain stem synaptosomes stayed unchanged but Vmax was almost doubled by the operation. Fluorescence histochemical findings also suggest sprouting of noradrenergic axons in specific brain regions.

Animals↗

[Hypoxic pulmonary vasoconstriction and angiotensin II blockade in calves (author's transl)].

The pulmonary vascular response to breathing low oxygen containing gas mixture was examined before and during Angiotensin II blockade in five open-chested newborn calves. Angiotensin II blockade was achieved by continuous infusion of Sar1-Ile5-Leu8-Angiotensin II (Saralasin), a competitive inhibitor of Angiotensin II. The hypoxic rise in pulmonary vascular resistance after blockade did not differ from that of control. It is concluded that Angiotensin II does not play a significant role in acute hypoxic pulmonary vasoconstriction in the calf.

Angiotensin II↗

Occlusive arteriopathy and brain tumor.

Four cases with the association of occlusive arteriopathy and brain tumor are presented. A clinical analysis of these cases and cases reported in the literature revealed that occlusive arteriopathy at the base of the brain was often associated with a slowly growing basal tumor in children. Possible causes of occlusive arteriopathy in these cases were compression of the circle of Willis by a slowly growing basal tumor, secondary artial occlusive changes by radiation therapy for a basal tumor, or vasculopathy associated with neurocutaneous syndrome. Symptoms of sudden onset or episodic nature suggest the presence of occlusive arteriopathy rather than the mass effect of a tumor. Cerebral angiography is mandatory whenever computerized tomography (CT), performed to rule out recurrence of a basal tumor, shows an ischemic lesion with low-density areas without any evidence of mass effect of the tumor. Cerebral angiography is also necessary when a basal tumor is suspected in children, particularly in cases associated with neurocutaneous syndrome and a basal tumor. Care should be taken not to scarify the abnormal vascular network at the base of the brain at the time of operation, because it is considered to be functioning as collateral circulation. The potential hazards of radiotherapy to radiation-induced occlusive changes of the circle of Willis must be considered in treating a benign basal brain tumor in children. Even in adults, repeated large doses of irradiation could cause occlusive arteriopathy.

Adult↗

[A case of spontaneous pontine hematoma in patient suspected of pontine glioma and multiple sclerosis (author's transl)].

A case of spontaneous pontine hematoma in young boy, with remitting and relapsing clinical course of up to 11 years, suspected of having pontine glioma or multiple sclerosis is reported. Differential diagnosis of these are mentioned with reference to our cases of pontine glioma. This patient was a man aged 16. At 5 years of age he had his first episode of double vision. 20 days after first episode, gait disturbance, left facial palsy and consciousness disturbance developed. Neurological and neuroradiological examination revealed a pontine glioma and radiotherapy was administered. All signs and symptoms resolved except for bilateral abducens palsy. Four months later, he again complained of gait disturbance and facial palsy. Examination revealed bilateral conjugate ocular palsy, left facial palsy and cerebellar ataxia. These symptoms again resolved spontaneously, except for bilateral abducens palsy. At age 16 years, having been asymptomatic for 10 years, he suddenly noticed loss of taste. At that time sensory disturbance of the left side of himself, right hearing disturbance, dysarthria and retardation urinae. Neurological examination revealed bilateral optic atropy, bilateral abducens palsy, left facial palsy, right hyperacuisis, dysarthria, left hemiparesis, hypesthesia of the left side of the body and left cerebellar ataxia. The vertebral angiography was no evidences of mass lesion and vascular anomalies. The computed tomography demonstrated a pontine hematoma. Conservative therapy was performed and these symptoms cleared off except for bilateral abducens palsy.

Brain Neoplasms↗

Studies on the cutaneous sensitization reaction of guinea pigs to purified aromatic chemicals.

The sensitization reactions to purified cinnamic aldehyde and its chemically related substances were investigated using the maximization test on guinea pigs. Mutual cross-sensitivities were also examined. Cinnamic aldehyde was found to be the most potent sensitizer in this series, and a strong cross-sensitizer. From the chemical structures of these substances, the following speculations were made. There was a tendency that as the number of hydrocarbons of alkyl groups replacing the alpha-hydrogen in the molecule increased, the rate of sensitization reaction declined. The conjugated system of double bonds was suspected to be a determinant factor in relation to the sensitization ability of the substances in this series.

Aldehydes↗