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Biomedical subjects

N Komai

Publications and source records attributed to N Komai.

At least 145 records · Page 8Linked to original sources
PubMed1984

[Morphological study on innervation of the cerebrospinal blood vessels. I. Cerebral blood vessels].

The distribution of nerve fibers in the cerebral blood vessels was studied by a catecholamine histofluorescence method, acetylcholinesterase (AChE) staining and immunohistochemistry. The ultrastructure of the terminal boutons in the vessel wall was also studied. In the adventitia of the cerebral artery, green fluorescence aminergic fibers and brownish AChE-positive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. The highest density of aminergic fibers were found in the dural sinus and the second highest in the internal cerebral vein. Serotonin immunoreactive nerve fibers were found along small intraparenchymal blood vessels such as perforating arteries in the brain stem, and arterioles and venules in the cerebral cortex. Under ultrastructural observation, a serotonin immunoreactive terminal was demonstrated in conjunction with the basement membrane of the capillary.

Acetylcholinesterase↗
PubMed1983

Moyamoya disease associated with intracranial aneurysms.

A case of moyamoya disease associated with multiple intracranial aneurysms is reported. The aneurysms were located at the bifurcation of the basilar artery and at the precommunicating segment of the right posterior-cerebral artery. They were found to be unruptured and clipped successfully through a right frontotemporal craniotomy. Outcome of the operation was satisfactory. We propose the operative indication for these cases on the basis of operative and radiological findings, and also discuss characteristic aspects of this disease.

Adult↗
PubMed1983

Innervation of the cerebral veins as compared with the cerebral arteries: a histochemical and electron microscopic study.

The distribution of nerve fibers in the cerebral veins was studied by catecholamine fluorescence simultaneously with acetylcholinesterase (AChE) histochemistry. A comparison of nerve fibers in the cerebral arteries was made. The ultrastructure of terminal boutons in the veins fixed with potassium permanganate was also studied. In the adventitia of the cerebral artery, green fluorescent aminergic fibers and brownish AChE-reactive (probably cholinergic) fibers were observed. In contrast, the cerebral venous system showed no AChE-positive fibers. Catecholamine fluorescent varicose fibers were detected in the dural sinus, the internal cerebral vein, and the superficial vein of Labbé. The highest density of aminergic fibers was found in the dural sinus and the second highest in the internal cerebral vein. Most of the terminal boutons in the adventitia of the cerebral veins were found adjacent to a muscle-like cell and showed only cored vesicles under electron microscopy. Results of our study suggest that the cerebral venous system has a neurogenic innervation, mainly from aminergic fibers, which is different from the neurogenic supply to the cerebral arterial system.

Animals↗
PubMed1983

Eye movements evoked by electrical stimulation of the frontal cortex in the coronary sulcus of the cat.

The frontal cortex concerned with eye movements was investigated by electrical stimulation in the cat. Stimulation of the lateral part of the frontal cortex at the coronary sulcus evoked rapid medial movement and enophthalmos of the contralateral eye. The latency of eye movement following cortical stimulation was found to be shorter in the coronary sulcus than in the medial wall of the hemisphere under the cruciate sulcus or in the presylvian sulcus.

Animals↗
PubMed1983

[Multiple malignant intracerebral schwannomas in von Recklinghausen's disease--report of a case].

Intracerebral schwannoma is very rare, and only nine cases of solitary intracerebral schwannoma have been reported since the first description by Gibson et al, in 1966. This report is the first case of multiple intracerebral schwannomas in Japan. Intracranial extracerebral schwannomas in von Recklinghausen's disease are sometimes encountered, but intracerebral ones have not been discovered. A case of multiple intracerebral schwannomas associated with von Recklinghausen's disease is reported in a 23-year-old male. He had been healthy until January 1979 when he was pointed out an abnormal shadow on chest roentgenogram. Although thoracic tumor revealed schwannoma in histological examination of surgical specimen, it transformed to malignant one during next 15 months. In July 1980, he complained of severe headache, vertigo, nausea and vomiting, and bilateral papilledema was proved. He was admitted to our clinic on August 8, 1980. Two large intracerebellar and four intracerebral tumors were revealed by computed tomography (CT). Angiography demonstrated avascular masses. The cerebellar tumors were totally extirpated on August 12, 1980. Histological diagnosis of the removed tumors approved malignant schwannoma, but their correlation to the chest tumor was unclear. Follow-up CT scans demonstrated that the supratentorial tumors increased in size during about three months. The chest tumor also increases in size. He died on November 12, 1980, but autopsy was not done. Pathogenesis of intracerebral schwannomas in this case is controversial, and we suggest that it is (1) multiple schwannomas in von Recklinghausen's disease with malignant transformation, or (2) metastasis from the chest tumor. But the conclusion remains unclear.

Adult↗
PubMed1982

Detection and mapping of six miniF-encoded proteins by cloning analysis of dissected miniF segments.

Various DNA subfragments were derived from miniF DNA by complete or partial PstI cleavage, and cloned in the plasmid vectors pBR322 or lambda dv1. The recombinant plasmids obtained were introduced into an Escherichia coli minicell-producing strain, and the plasmid-coded proteins were radiolabeled and analyzed by gel electrophoresis. Six miniF-encoded proteins, larger than 11 000 daltons, were detected and their coding regions were mapped on the F plasmid genome. Three of them were assigned by taking into account the known nucleotide sequences (Murotsu et al. 1981; K. Yoshioka, personal communication). The coding directions of some proteins were determined by inserting the lac promotor into one of the recombinant plasmids and analyzing the increase in production of the proteins. The coding direction of the five proteins analyzed so far was uniform. Comparison of these results with a functional map of miniF suggested possible roles of the proteins.

Bacterial Proteins↗
PubMed1981

Comparative anatomy of the distribution of catecholamines within the inferior olivary complex from teleosts to primates.

The distribution of catecholamine (CA) in the inferior olivary complex (IO) of various vertebrate (from fish to monkey) was investigated by means of the histofluorescence technique. In addition, using rats, a further attempt was made to elucidate the origins of CA in the IO. The IO of the lower vertebrates (from fish to birds) was in general poorly innervated by the CA neuron system. IO in the lower mammals, such as insectivora and bats, contained only a few CA nerve terminals, while that in the higher mammals such as rat, guinea pig, rabbit, cat, and monkey revealed quite a number. In these animals, species-species patterns of CA nerve terminals were found. In the rat, the highest concentration was observed in the dorsal lamella of the principal nucleus and in guinea pig ventral lamella. In the rabbit and cat, maximum CA nerve terminals were detected in the dorsal accessory nucleus, while in the monkey, they were detected in the medial accessory nucleus. The retrograde tracer technique of horseradish peroxidase (HRP) suggested that the main source of the abundant CA terminals in IO of the rat might be A1, A2, and A3 noradrenaline neurons, though not locus coeruleus and not dopaminergic ones.

Animals↗
PubMed1981

The association of intracranial aneurysms and arteriovenous malformation of the brain. Case report.

A case of intracranial multiple aneurysms associated with an arteriovenous malformation (AVM) is described. Three aneurysms were found arising from an enlarged anterior cerebral artery feeding an AVM. In spite of the fact that two of these aneurysms received no surgical treatment, they disappeared almost completely several months after excision of the AVM. Seventy-three previously reported cases of cerebral aneurysms associated with AVM's are reviewed, and the effect of hemodynamic stresses on the development of these aneurysms is summarized.

Adult↗