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Biomedical subjects

T Tagawa

Publications and source records attributed to T Tagawa.

At least 145 records · Page 8Linked to original sources
PubMed1990

Distribution and ontogeny of chromogranin A and tyrosine hydroxylase in the carotid body and glomus cells located in the wall of the common carotid artery and its branches in the chicken.

Development and distribution of chromogranin A and tyrosine hydroxylase in the carotid body and glomus cells located in and around arteries were examined in chickens at various developmental stages by an immunohistochemical staining. In 9-day-old embryos, numerous cells immunoreactive for tyrosine hydroxylase were already detected in the connective tissue surrounding the carotid body. Some of these cells also showed immunoreactivity for chromogranin A. At 10 days of incubation, a few cells immunoreactive for tyrosine hydroxylase and chromogranin A were detected within the carotid body parenchyma. At 12 days of incubation, almost all glomus cells of the carotid body were intensely immunoreactive for these substances. Furthermore, numerous tyrosine hydroxylase- and chromogranin A-immunoreactive cells were observed in the wall of the common carotid artery, along the whole length of the carotid body artery, and around the roots of the inferior thyroid artery, the ascending esophageal artery and the esophagotracheobronchial artery; the cells already exhibited adult pattern of distribution at this stage of development. Thereafter, glomus cells immunoreactive for both substances gradually increased in number and in intensity of immunoreactivity with age, although the cells located in the wall of the common carotid artery lost immunoreactivity for tyrosine hydroxylase after hatching.

Animals↗
PubMed1990

Purification of rabbit bone morphogenetic protein derived from bone, dentin, and wound tissue after tooth extraction.

Bone morphogenetic protein (BMP) was extracted from bone matrix, dentin matrix, and wound tissue after tooth extraction in rabbits, and purified. These purified fractions were shown to be homogeneous by sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis (SDS-PAGE), and induced new bone in situ in 3 weeks when implanted into the calf muscles of Wistar rats. The dentin matrix-derived BMP was different from the other two types in molecular weight and the properties revealed in the process of purification. However, each tissue-derived BMP was shown to induce new bone growth in a bioassay of xenogenic implantation. For this reason, BMP is thought to have subunits with certain commonalities in different tissue.

Animals↗
PubMed1990

Interaction of zonisamide with benzodiazepine and GABA receptors in rat brain.

The effects of zonisamide on [3H]flunitrazepam binding and [3H]muscimol binding were studied in Sprague-Dawley rat brain. Specific [3H]flunitrazepam bound was decreased to 64.6 +/- 5.6% (mean +/- SD, n = 5, p < 0.002) and 91.9 +/- 4.0% (p < 0.005) by the addition of 10(-3) M and 10(-4) M zonisamide, respectively. Scatchard plot analysis of [3H]flunitrazepam binding with 10(-3) M of zonisamide revealed an increased Kd value with no change in Bmax. No inhibitory effect of zonisamide was seen on the enhancement of specific [3H]flunitrazepam binding by GABA. As for the effects on GABA receptors, specific [3H]muscimol bound was decreased to 27.7 +/- 10.4% (mean +/- SD, n = 4, p < 0.005) and 68.3 +/- 3.7% (mean +/- SD, n = 4, p < 0.005) by the addition of 10(-3) M and 10(-4) M zonisamide, respectively. Since therapeutic serum level of zonisamide are around 10(-4) M, these results suggest that zonisamide neuropharmacologically interacts with the GABA/benzodiazepine receptor ionophore complex in a manner similar to phenytoin.

Animals↗
PubMed1990

[3H]zonisamide binding in rat brain.

We previously reported that zonisamide inhibits both [3H]flunitrazepam and [3H]muscimol binding in rat brain. In the present study, [3H]zonisamide was found to bind in a saturable fashion to the crude synaptosomal fraction of whole rat brain. Linear regression analysis of the binding data in the Scatchard plot indicated a Kd of 90 nM, and a maximal binding capacity of 1.40 x 10(3) fmol/mg protein. Displacement studies revealed an inhibitory effect of clonazepam and an enhancement effect of GABA on specific [3H]zonisamide binding. These results suggest that specific [3H]zonisamide binding sites may have a tight correlationship with benzodiazepine receptors in rat brain.

Animals↗
PubMed1990

Preferential binding of cisplatin to mitochondrial DNA and suppression of ATP generation in human malignant melanoma cells.

Effects of cisplatin on mitochondria in human malignant melanoma from gingiva were investigated. Cisplatin bound about 50 times more to mitochondrial DNA than to chromosomal DNA. NADH-ubiquinone reductase was decreased 48 h after the administration to about 40% of the initial level, and cellular ATP level was also depressed at that time. A good correlation was observed between the energy status and NADH-ubiquinone reductase activity. These results suggest that the preferential binding of cisplatin to mitochondrial DNA results in the inhibition of NADH-ubiquinone reductase and consequently in the disturbance of ATP generation.

Adenosine Triphosphate↗
PubMed1989

Purification of bone morphogenetic protein derived from bovine bone matrix.

Bone morphogenetic protein (BMP) was extracted from the bovine bone matrix and purified by liquid chromatography. The molecular weight of the BMP was 18 kDa by SDS-PAGE, and its pI value was 4.9. Amino acid analysis suggested that the BMP is a polypeptide containing 163 amino acids. In the present study, telopeptide-free type I collagen was used as a carrier of BMP.

Amino Acids↗
PubMed1989

Monostotic fibrous dysplasia with involvement of the mandibular canal.

A 72-year-old woman sought treatment with a rare monostotic fibrous dysplasia occurring in the mandible and involving the mandibular canal. Her chief complaint was swelling, which had appeared about 2 years previously, had enlarged gradually, and was associated with spontaneous pain. X-ray film examination revealed a ground-glass opaque image of blurred demarcation, and 99mTc-methylene diphosphonate bone scintigraphy disclosed an area of marked radioisotope uptake. Histopathologic examination revealed the area of bone marrow and spongy bone to be replaced by fibrous tissue, irregular beam-shaped woven bone, and lamellar bone. Contouring of the expanded portion of the bone and surgical decompression of the mandibular canal were performed with good results.

Aged↗
PubMed1989

Aggressive infantile fibromatosis of the submandibular region.

Aggressive infantile fibromatosis is an unusual, tumor-like, proliferative lesion which grows infiltratively. The clinical and histological features of aggressive infantile fibromatosis in the submandibular region of a 3-year-old girl are reported.

Child, Preschool↗
PubMed1989

EEG and CT abnormalities in xeroderma pigmentosum.

Xeroderma pigmentosum associated with neurological abnormalities is a less familiar neurocutaneous disorder. In this report, 35 patients with group A xeroderma pigmentosum were assessed for neurological complications. Of these, 17 showed microcephaly and 24 mental retardation. Of 25 patients over 7 years of age, 22 had sensorineural deafness and 12 showed spinocerebellar signs such as nystagmus, dysarthria, tremor and ataxia, while none below 7 years of age had such neurological complications. Thirty-five EEG studies were performed on 29 patients, and 15 showed intermittent spindles of grouped theta waves with abnormal slow background activity and a poorly developed alpha rhythm, suggesting immature brain development or a regression from normal brain function in many areas including the diencephalon. Twenty-six patients were examined by cranial CT scan, of whom 20 showed abnormal CT findings such as ventricular dilatation, diffuse cortical atrophy, and marked thickening of the calvarial bones. The incidence of abnormal EEG and CT findings increased with advancing age in accordance with the development of neurological complications in the CNS, thus suggesting a chronic progressive degenerative disease.

Adolescent↗
PubMed1989

Vitamin E status in pediatric patients receiving antiepileptic drugs.

Decreased vitamin E levels have been reported in epileptic children receiving antiepileptic drugs (AED). In order to investigate the tocopherol status of patients receiving AED, the alpha-, beta, gamma- and delta-tocopherol concentrations were each determined in 447 patients' serum samples using a high-performance liquid chromatographic method. In pediatric patient samples (n = 244, aged 1-16 years), there was a negative relationship (p less than 0.02; r = -0.153) between age and alpha-tocopherol levels, while there was a positive relationship (p less than 0.05; r = 0.142) between age and gamma-tocopherol levels. The mean (+/- SD) alpha-tocopherol levels (0.73 +/- 0.23 mg/dl) in the older children (n = 166, aged 7-16 years) were significantly lower (p less than 0.05) than the levels (0.83 +/- 0.23 mg/dl) found in the younger children (n = 78, aged under 7 years). Administration of alpha-tocopherol acetate, 3 mg/kg/day to 8 children and 5 mg/kg/day to 4 children, increased alpha- and total tocopherol levels (p less than 0.01 for both), while gamma-tocopherol levels and serum lipid peroxide levels were decreased (p less than 0.01 for both). In 203 epileptic patient samples (over 16 years of age), the mean alpha-tocopherol level (0.92 +/- 0.28 mg/dl) tended to be lower (p less than 0.1) than in 22 healthy adult controls (1.01 +/- 0.26 mg/dl).

Adolescent↗
PubMed1989

[Ultrasonic Doppler assessment of hemodynamics in extra-intracranial arterial anastomosis in children with Moyamoya disease].

Recently the extra-intracranial (EC/IC) arterial bypass operation has been introduced in the treatment of Moyamoya disease and excellent postoperative outcomes have been reported. To assess the cerebral hemodynamic changes after the bypass surgery, ultrasonic Doppler flowmetry was performed in 10 children with Moyamoya disease. Their surgical treatments included superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis or encephalo-duro-arterio-synangiosis. The flow velocity and pattern of the major cerebral arteries and STAs, the donor artery of the bypass, were studied both before and after the operation. The results of Doppler flowmetry were compared with clinical symptoms and angiographical findings. Though the Doppler sonography of the major cerebral arteries showed little change, the flow velocity of the STAs revealed a pronounced and rapid increase after the bypass surgery. The flow pattern of the STAs, which was of the external carotid type preoperatively, changed to the internal carotid type postoperatively. These ultrasonic Doppler findings were thought to be due to a decrease in the peripheral vascular resistance, and suggested a good patency of the bypass arteries. These results of the Doppler flowmetry were in good agreement with clinical and EEG improvement and the findings of the postoperative cerebral angiography. It is suggested that ultrasonic Doppler flowmetry is a noninvasive and reliable method of assessing the function of the EC/IC bypass in children with Moyamoya disease.

Adolescent↗
PubMed1988

Innervation of the C cells of chicken ultimobranchial glands studied by immunohistochemistry, fluorescence microscopy, and electron microscopy.

Innervation of the ultimobranchial glands in the chicken was investigated by immunohistochemistry, fluorescence microscopy and electron microscopy. The nerve fibers distributed in ultimobranchial glands were clearly visualized by immunoperoxidase staining with antiserum to neurofilament triplet proteins (200K-, 150K- and 68K-dalton) extracted from chicken peripheral nerves. The ultimobranchial glands received numerous nerve fibers originating from both the recurrent laryngeal nerves and direct vagal branches. The left and right sides of the ultimobranchial region were asymmetrical. The left ultimobranchial gland had intimate contact with the vagus nerve trunk, especially with the distal vagal ganglion, but was somewhat separated from the recurrent nerve. The right gland touched the recurrent nerve, the medial edge being frequently penetrated by the nerve, but the gland was separated from the vagal trunk. The left gland was innervated mainly by the branches from the distal vagal ganglion, whereas the right gland received mostly the branches from the recurrent nerve. The carotid body was located cranially near to the ultimobranchial gland. Large nerve bundles in the ultimobranchial gland ran toward and entered into the carotid body. By fluorescence microscopy, nerve fibers in ultimobranchial glands were observed associated with blood vessels. Only a few fluorescent nerve fibers were present in close proximity to C cell groups; the C cells of ultimobranchial glands may receive very few adrenergic sympathetic fibers. By electron microscopy, numerous axons ensheathed with Schwann cell cytoplasm were in close contact with the surfaces of C cells. In addition, naked axons regarded as axon terminals or "en passant" synapses came into direct contact with C cells. The morphology of these axon terminals and synaptic endings suggest that ultimobranchial C cells of chickens are supplied mainly with cholinergic efferent type fibers. In the region where large nerve bundles and complex ramifications of nerve fibers were present, Schwann cell perikarya investing the axons were closely juxtaposed with C cells; long cytoplasmic processes of Schwann cells encompassed large portions of the cell surface. All of these features suggest that C-cell activity, i.e., secretion of hormones and catecholamines, may be regulated by nerve stimuli.

Animals↗
PubMed1988

Chiari I malformation with quadriplegia and respiratory disturbance in an infant.

Chiari I malformation consists of variable downward displacement of the cerebellar tonsils. Quadriplegia, respiratory disturbance and pain are common in Chiari I malformation in adults. However, there are no reports of this syndrome in early childhood. We report the case of a 9-month-old girl with Chiari I malformation who had quadriplegia with muscle weakness and who developed respiratory disturbance as an early symptom. The causes of the symptoms of Chiari I malformation are discussed. The use of MRI is proposed as a more useful diagnostic technique than myelography for these patients since MRI is less likely to aggravate the respiratory disturbance.

Age Factors↗
PubMed1988

Intravenous injection of flunitrazepam for status epilepticus in children--two case reports.

Two cases of status epilepticus are reported, whose seizures responded well to the injection of flunitrazepam. One patient had generalized tonic clonic seizures and the other had partial seizures. The improvement of their condition was confirmed by both clinical and electroencephalographic examinations. There were no serious side effects observed. Flunitrazepam might have a potential efficacy for the treatment of status epilepticus of both generalized and partial seizures.

Electroencephalography↗