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Biomedical subjects

T Tagawa

Publications and source records attributed to T Tagawa.

At least 181 records · Page 10Linked to original sources
PubMed1983

Internal carotid velocity measurements in children with cerebrovascular disease.

Internal carotid artery flow velocity was evaluated by the Doppler ultrasound method in 32 children with cerebrovascular disease. The average maximal blood velocity (A/L) and end-diastolic blood velocity (d) were compared with each other as indices of blood flow velocity. The right and left mean A/L and d of moyamoya disease were significantly lower than those observed in normal children. The A/L and d of the affected side both in internal carotid artery occlusion and in middle cerebral artery occlusion were also significantly low. In the subarachnoid hemorrhage after rupture, these values were significantly low. In basilar artery occlusion, these values were similar to those in normal children. The results of this study indicate that Doppler ultrasound assessment of internal carotid flow velocity provides noninvasive reliable information for the diagnosis of cerebrovascular disease in childhood.

Basilar Artery↗
PubMed1982

Histological and scanning electron microscopic study of tissue invasion of Bangerter nylon implant after enucleation.

An incidentally extirpated Bangerter-type nylon implant was examined by light microscopy and scanning electron microscopy. Three months after implantation, the implant was densely filled with tissues, which were shown by light microscopy to be muscle cells in the margin of the implant; the muscle cells were fixed there at the time of implantation, and fibrocytic cells were inside the implant. Scanning electron microscopy showed interlacing fibrous cells with erythrocytes and leukocytes among the nylon fibers, lamellar accumulation of fibrous cells around nylon fibers, and a smooth surface of the margin of the nylon implant. This invasion of fibrous cells into the nylon implant is one reason why the Bangerter type of nylon implant rarely falls out of the orbital socket.

Connective Tissue↗
PubMed1982

Internal carotid blood flow velocity in children with cerebral palsy by Doppler Ultrasound method.

Cerebral blood flow assessed noninvasively by Doppler ultrasound technique in 30 children with cerebral palsy. The average maximal blood velocity (A/L) and end-diastolic blood velocity (d) of internal carotid artery were measured before and during brief digital compression of contralateral common carotid artery. Both A/L and d values in children with cerebral palsy were significantly lower than those observed in normal healthy children. In 13 children with spastic hemiplegia, no significant difference in either A/L or d was seen between the non-affected side and affected side both before and during brief digital compression. This data suggests that mean cerebral blood flow decreases in our children with cerebral palsy, and that no lateralization of the decrease in hemispheric cerebral circulation in hemiplegic children may explain by supposing the existence of generalized bilateral brain damage in those subjects.

Adolescent↗
PubMed1982

Antiepileptic effects of clobazam in children.

Many benzodiazepines used as anticonvulsants have nitrogen radicals in positions 1 and 4. Clobazam has nitrogen radicals in positions 1 and 5. We studied the antiepileptic effect of clobazam in 36 patients with intractable epilepsies in childhood. Their ages were 1 year 1 month to 16 years 5 months (mean 8 years). The mean initial dose was 0.33 mg/kg of daily doses and increased up to 0.71 mg/kg. Nine cases (primary generalized epilepsy 2/2, secondary generalized epilepsy 7/29) were completely free from seizures, and another 9 (secondary generalized epilepsy 8/29, partial epilepsy 1/5) experienced a decrease of 50% or more in seizure frequency. Seizure frequency did not change in 16, and increased in the other 2 (secondary generalized epilepsy 2/29). The antiepileptic effects were observed on the first day to 10th day after clobazam treatment. There were recurrences of seizures in 4 out of 9 patients with complete control of seizures, 1 month alter in 3 and 10 months later in one. Mean serum clobazam level of 7 improved cases was 73 ng/ml and that of 3 cases with no response was 94 ng/ml. Although mild clinical side effects such as drowsiness were observed transiently in 17 cases, no abnormality was found in laboratory investigations performed.

Adolescent↗
PubMed1981

Primary malignant melanoma of the oral cavity. Case report and establishment of melanoma cell line.

Malignant melanomas rarely grow in the oral mucosa and few established melanoma cell lines originate from the gingiva. Our patient was a 59-year-old man with a dark mass at the upper incisive gingiva and a large lymphadenopathy in the submandibular region. The gingival biopsy showed malignant melanoma. Because of the marked metastases, he received both chemotherapy and immunotherapy. Although regression and discoloration of the tumors were seen, he died of respiratory failure 9 months after admission. At autopsy, metastatic amelanotic and melanotic melanomas were found in various organs. Cells were obtained for tissue culture from pleural fluids of the patient. Eagle's MEM or RPMI1640 with 20% f.c.s. was used for the culture medium, and cells were found to attach to the bottom of the culture tube and to show no contact inhibition. Electron microscopy of primary cultured cells showed premelanosomes in the cytoplasm. The cells were transplantated into nude mice for studies of tumorgenesis and for serial transplantation of the tumor. A progressive tumor appeared. At present (June 19, 1980), 110 passages have been made and the cells are growing well. They were named HMG.

Animals↗
PubMed1980

Hypoglycemia in a child with hepatoblastoma.

A five-year-old boy with hepatoblastoma, who showed a severe hypoglycemia as an initial symptom, was studied. After resection of tumors, hypoglycemia disappeared and did not recur despite recurrence of tumor. A high concentration of insulin-like activity (ILA) was found in preoperative serum and in the tumor extract. Hypoglycemia in this patient seemed to depend mainly on ILA and in part on liver enzyme activities related to carbohydrate metabolism.

Carcinoma, Hepatocellular↗
PubMed1979

A histochemical study of the innervation of the cerebral blood vessels in the domestic fowl.

Adrenergic and cholinergic nerves innervating the cerebral arteries of the domestic fowl were examined by specific histochemical techniques. The adrenergic nerve plexuses of the cerebral carotid system are markedly denser than those of other vertebrates observed by similar techniques. They form longitudinally elongated meshworks of fine fibres in the vascular wall of the arterial branches. Those innervating the vertebro-basilar system are less dense and more elongated, and, as the size of the artery diminishes, the fibres of the plexus become coarser. In the small pial and parenchymal arteries they are reduced to a few fibres running parallel to, or spiralling around the vascular axis. The cholinergic nerve plexuses are not as dense as the adrenergic system. The acetylcholinesterase activity is very weak, except in the plexuses innervating the cerebral carotid artery and proximal portion of the anterior and posterior rami. In the vertebro-basilar system, a few thick nerve bundles run alongside the blood vessels of the vertebral and basilar arteries. Cholinergic nerves enter the cranial cavity along the internal carotid, the vertebral and possibly the cerebroethmoidal arteries. Intracerebral capillaries and some arterioles are not innervated with cholinergic and adrenergic fibres of peripheral origin, but with ones arising from parenchymal nerve cells.

Adrenergic Fibers↗
PubMed1979

A histochemical study on the innervation of cerebral blood vessels in the bullfrog.

Specific histochemical techniques for the demonstration of catecholamine and acetylcholinesterase have been used to study the distribution of adrenergic and cholinergic nerves on the cerebral blood vessels of bullfrog, Rana catesbeiana. The adrenergic nerve meshworks on the cerebral arteries of bullfrog were less dense, had a more elongate appearance along the arterial axis as compared with those of mammals and were rather similar to those of snakes. The nerve plexuses on the cerebral carotid artery and its main branches were somewhat denser than those on the basilar artery. The most characteristic feature of innervation in the bullfrog cerebral vessels was that no acetylcholinesterase-positive fibres were observed on the extraparenchymal arteries, whereas, in all higher vertebrates investigated so far, the cerebral arteries have been found to be dually innervated although differences in the density of innervation of the two nerves may exist. This suggests that the peripheral adrenergic innervation on the cerebral blood vessels appeared earlier than the cholinergic one in the evolution of vertebrates. On the other hand, both adrenergic and acetylcholinesterase-positive fibres were observed in close contact with parenchymal arterioles and capillaries suggesting the possible existence of a dual central innervation. This feature, however, was by no means common. Thus, the central neurons have a significant influence on the cerebral circulation in the bullfrog is somewhat equivocal. Most of the pial and the parenchymal small vessels and the parenchymal capillaries exhibited a heavy acetylcholinesterase activity on the vascular walls. Although the significance of the enzyme is obscure as yet, this has to be considered in relation to the regulatory mechanism of the cerebral circulation.

Adrenergic Fibers↗
PubMed1977

A histochemical study of the innervation of cerebral blood vessels in the snake.

Dual innervation of snake cerebral blood vessels by adrenergic and cholinergic fibres was demonstrated with the use of histochemical methods. Although the nerve plexuses are somewhat less dense, the essential features of innervation of the blood vessels are similar to those of mammals with the exception that the adrenergic plexuses are more prominent than the cholinergic plexuses. The major arteries of the cerebral carotid system have a rich nerve supply. However, the innervation is less rich in the basilar and poor in the spinal (vertebral) arteries. Although the arteries supplying the right side of head are poorly developed, three pairs of arteries, cerebral carotids, ophthalmics and spinals, supply the snake brain. The carotids and ophthalmics are densely innervated and are accompanied by thick nerve bundles, suggesting that the nerves preferentially enter the skull along those arteries. Some parenchymal arterioles are also dually innervated. Connection between the brain parenchyma and intracerebral capillaries via both cholinergic and adrenergic fibres was observed. In addition cholinergic nerve fibers, connecting capillaries and the intramedullary nerve fibre bundles, were noticed. Capillary blood flow may be influenced by both adrenergic and cholinergic central neurons. The walls of capillaries also exhibit heavy acetylcholinesterase activity. This may indicate an important role for the capillary in the regulation of intracerebral blood flow.

Adrenergic Fibers↗
PubMed1976

Adrenergic and cholinergic innervation of the arteriovenous anastomosis in the rabbit's ear.

The distribution of adrenergic and cholinergic nerves in the arteriovenous anastomosis in the rabbit's ear was studied light microscopically using specific histochemical techniques for catecholamines and acetylcholinesterase. Histochemical observations was made with whole stretch preparations and cryostat or paraffin sections. Both kinds of nerves showed similar distribution, though the adrenergic innervation was denser than the cholinergic one. The intermediate segments of the anastomoses, which were characterized by a very thick wall, had the most dense innervation. The small arteries and arterial segments had a moderate innervation whereas most of the small veins and venous segments had few nerve fibers. The segmental variation in the vasomotor nerve supply clearly suggests that the intermediate segment has the most active contractility. An unusually rich innervation in the anastomosis, therefore, indicates the significance of the neurogenic mechanisms in the vasomotor control of the anastomosis.

Animals↗