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Biomedical subjects

K Oyanagi

Publications and source records attributed to K Oyanagi.

At least 91 records · Page 5Linked to original sources
PubMed1990

Focal pachygyria with unusual vascular anomaly.

A case of focal pachygyria with an unusual vascular anomaly is reported. Preoperative magnetic resonance imaging demonstrated few and broad gyri, and an abnormally thickened cortex of the right frontal lobe. In addition, T2-weighted imaging showed a high intensity lesion beneath the thickened cortex. In the pachygyric cortex, the peripheral portions of the arteries were tortuous and irregularly dilated, and prominent deep medullary veins were found draining into the subependymal veins. Histological examination revealed a decreased number of neurons with no tendency towards lamination, and degenerative changes with gliosis in the white matter. These findings suggest that the etiology of this anomaly may be gradual perfusion failure restricted to the territory of the anomalous vessels through the period of neuronal migration to the post-migratory, perinatal stage.

Cerebral Angiography↗
PubMed1990

A case of carbamylphosphate synthetase-I deficiency associated with secondary carnitine deficiency--L-carnitine treatment of CPS-I deficiency.

We describe a male infant with congenital hyperammonaemia due to partial carbamylphosphate synthetase-I (CPS-I) deficiency. At 21 days of age, he had convulsions and at 53 days of age hyperammonaemic coma. Therapy with sodium benzoate, L-arginine, essential amino acids, L-carnitine and peritoneal dialysis lowered the blood ammonia levels, and his clinical manifestations improved. The CPS-I activity in liver tissue obtained by open biopsy was about 25.6% of normal values. The serum and urine free carnitine levels in the patient decreased during the hyperammonaemic crisis and were low at 7 months of age. After oral administration of L-carnitine (10 mg/kg per day) at 7 months of age, the mean blood ammonia levels decreased significantly, accompanied by an increase in serum and urine free carnitine levels. We propose the use of L-carnitine therapy to prevent secondary carnitine deficiency in patients with CPS-I deficiency as well as ornithine transcarbamylase (OTC) deficiency.

Amino Acid Metabolism, Inborn Errors↗
PubMed1990

Abnormal glycosphingolipid metabolism in the nervous system of galactosialidosis.

In an autopsy case of galactosialidosis, GM3, GM2, GM1, and GD1a were accumulated in sympathetic and spinal ganglia and grey matter of the spinal cord. Especially, the accumulations of GM3 and GM2 amounted to 41- and 86-fold increases in sympathetic ganglia, respectively, as compared to normal controls. In addition LacCer, GA2 and GA1 were accumulated in sympathetic and spinal ganglia. The accumulations of GM3 and GD1a are considered to be the result of defective lysosomal sialidase activity and the accumulation of GM1, LacCer and GA1 is also considered to be due to decreased beta-galactosidase activity in this disorder. To better understand the possible mechanism of GM2 accumulation, we determined the activity of GM2 synthesizing enzyme (GM3:UDP-GalNAc transferase), as well as hexosaminidase activity, in sympathetic ganglia, but they did not change. Abnormal ganglioside and neutral glycosphingolipid metabolism, as well as sialyloligosaccharide and sialylglycoprotein metabolism, may be involved in the pathogenesis of this disorder.

Biomechanical Phenomena↗
PubMed1990

[An autopsied case of manifesting chorea, serum antibody to brain proteins, neuronal degeneration in striatum and grumose degeneration in dentate nucleus].

A 49-year-old man complained of difficulty in writing due to choreic involuntary movement in the right hand, which spread gradually to his left hand, face, lower extremities and trunk during next nine years. He also showed difficulties in speech and swallowing. His family noticed his memory disturbance and change of his character. Ten years later, mental deterioration, dysarthria and dysphagia were manifested. He showed facial grimacing and dancing gait. Deep tendon reflexes were exaggerated with no pathological reflexes. Muscle tone was rigid at his ankles. He showed no ataxia nor sensory impairment. At about 61 years old, choreic movement was decreased and rigidity spread in all extremities with joints' constructure. During next one or two years, choreic movement diminished and was restricted to his face. The extremities became more rigid and voluntary movement was severely impaired. He became mutistic with severe mental deterioration. He died at the age of 65. None of his family suffered from the same disease. Routine blood examination was normal, and there were no acanthocytes. Brain CT showed marked dilatation of lateral and third ventricles, and mild cerebral cortical atrophy. The head of caudate nucleus was also atrophic. The total protein level in the CSF was elevated to 79-121 mg/dl, and IgG% was 13.7-26.6 for last six years. Anti-CNS antibodies in the serum reacted with brain proteins of 156 kDa and 82 kDa. Pathological examination showed severe atrophy of the caudate nucleus, putamen, globus pallidus, cerebral cortex and cerebral white matter.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[A case of xanthoma of the skull].

The reports in the radiologic literature of osseous xanthoma are very rare. We reported a case of xanthoma of the skull without hyperlipidemia. The bony changes is well-marginated radiolucent lesion with marginal sclerosis and an central nidus of bone.

Bone Diseases↗
PubMed1989

Correlative decrease of large neurons in the neostriatum and basal nucleus of Meynert in Alzheimer's disease.

A quantitative investigation was performed on the large neurons in the neostriatum and basal nucleus of Meynert (bnM) in patients with Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). The degree of decrease of the large neurons in the neostriatum was quite similar to that in the bnM; these decreases were significantly correlative in AD, but not in PSP. These findings indicate that the large neurons in the neostriatum and bnM, which are considered to be cholinergic and to exclusively possess nerve growth factor receptors in the cerebrum, degenerate simultaneously in an equal ratio in AD.

Aged↗
PubMed1989

A quantitative investigation of the substantia nigra in Huntington's disease.

To elucidate the quantitative and topographical changes of neurons in the substantia nigra in Huntington's disease (HD), sections from 4 HD patients and 8 age-matched control subjects were stained with cresyl violet and the numbers and localization of pigmented and nonpigmented neurons in the substantia nigra were examined. This study revealed a decrease of about 40% (p less than 0.01 or p less than 0.05) in neuronal number and a shrinkage of both pigmented and nonpigmented neurons in the substantia nigra in HD. Pigmented neuron number was decreased markedly in the ventral cell group. Loss of the neurons occurred in the medial and lateral thirds, but relative sparing of the neurons was seen in the central part of the substantia nigra. In contrast, loss of nonpigmented neurons was relatively uniform in the substantia nigra although it was more severe in the central part. We conclude that a primary neuronal degeneration occurs in the substantia nigra in HD.

Adult↗
PubMed1989

Occurrence of 15-nm-wide straight tubules in neocortical neurons in progressive supranuclear palsy.

Ultrastructural investigations were carried out on the cerebral neocortex in two cases of progressive supranuclear palsy. In both cases, characteristic 15-nm-wide straight tubules were observed in the neurons. The numbers of cells containing the straight tubules and of tubules in individual cells were small. However, the occurrence of the tubules strongly suggests that the cerebral neocortex is also exposed to the disease process in progressive supranuclear palsy.

Aged↗
PubMed1989

Evidence for sequential degeneration of the neurons in the intermediate zone of the spinal cord in amyotrophic lateral sclerosis: a topographic and quantitative investigation.

To elucidate the degenerating mechanism of the neurons in the intermediate zone of the spinal cord in classical amyotrophic lateral sclerosis (ALS), the spinal neurons in a patient with ALS, whose muscular strength was fairly well preserved up to death, were examined quantitatively and topographically, and compared with the data of advanced ALS patients and age-matched control subjects reported previously. In advanced ALS patients, anterior horn cells completely disappeared and the medium-sized (nuclear area; 71-150 microns 2) and large (nuclear area; greater than 151 microns 2) neurons in the intermediate zone were severely reduced. In the present case, however, the loss of anterior horn cells was severe but the degree was not equal to that of advanced ALS patients, and the neurons in the intermediate zone were quite well preserved. The finding indicates that the primary degeneration may occur in the anterior horn cells and the neurons in the intermediate zone degenerate sequentially in the spinal gray matter in ALS.

Amyotrophic Lateral Sclerosis↗
PubMed1989

The auditory system in methyl mercurial intoxication: a neuropathological investigation on 14 autopsy cases in Niigata, Japan.

The auditory system in 14 autopsy cases of methyl mercurial intoxication in Niigata was examined neuropathologically. In addition to degeneration of the transverse temporal gyrus, there was also either significant loss of small myelinated fibers or decrease of large neurons in the cochlear nerve, ventral cochlear nucleus and inferior colliculus. The degree of decrease was higher in acute patients than in the chronic, and was not correlative to the severity of cerebrovascular sclerosis. The hearing impairment in methyl mercurial intoxication may be induced by the combined degeneration of the neurons or nerve fibers of these structures in both acute and chronic patients.

Adult↗
PubMed1989

The role of amino acids and their transport systems in the regulation of ureogenesis in the primary culture of adult rat hepatocytes.

The biosynthesis of urea, the metabolism of ammonia and the transport of amino acids were studied using the primary culture of hepatocytes from adult rats. The urea synthesis and ammonia detoxication were affected by the amino acids of urea cycle intermediates, such as ornithine, arginine and aspartate. When the hepatocytes were incubated in the medium containing 1 mM ammonium chloride, the transport activity of system-A, which was determined by the uptake of specific substrate methyl-2-amino isobutyric acid (MeAIB), did not change compared with the control level. However, the transport activity of ornithine was increased to a maximum after 4 hr of incubation with ammonia, and then decreased gradually to twice the control level. The activity of ornithine transcarbamylase (OTC) increased to twice the control. These results indicated that the amino acids of urea cycle intermediates, especially ornithine, can be the important regulators of ureogenesis.

Amino Acids↗
PubMed1989

Neonatal hyperammonemia associated with carnitine deficiency.

We report a case of neonatal hyperammonemia associated with secondary carnitine deficiency. She suffered from hyperammonemia soon after the birth, and then presented severe metabolic acidosis at 2 months of age. She was successfully treated for acidosis with oral administration of L-carnitine (100 mg/kg/day). Since hyperammonemia recurred with the increase of protein intake, it was necessary to increase the dose of carnitine to 150 mg/kg/day. Urea cycle enzymopathies were excluded from the laboratory data. The urinary organic acid profiled by gas chromatography mass spectrometry revealed no abnormalities. It was found that the carnitine contents in serum urine and muscle were decreased. After we investigated the carnitine status in other members of the family, the brother of this patient, who had died of metabolic acidosis and hyperammonemia of unknown etiology in the neonatal period, was also revealed to have carnitine deficiency. Since specific enzyme defects which caused secondary carnitine deficiency could not be detected in our patients, further biochemical characterization would be necessary to clarify the cause of hyperammonemia.

Ammonia↗
PubMed1989

[The vestibular system and cerebellum in organic mercury intoxication; an otolaryngological and neuropathological investigation on 14 autopsy cases in Niigata].

The vestibular system consisting of vestibular ganglion, nerve and inferior, medial, lateral and superior nuclei and fastigial nucleus, cerebellar vermis, flocculus and hemisphere in 14 autopsy cases of methyl mercury intoxication in Niigata and 12 age-matched controls were examined neuropathologically. The findings were evaluated semiquantitatively, that is, -; normal, +/-; gliosis alone, +; loss of neurons or myelinated fibers less than about 40%, ++; loss of neurons from about 41 to 80%, ; loss of neurons more than about 81%. The results were compared to the records of the equilibrium function of those patients. The examinations on the equilibrium function revealed positive findings in the optokinetic and positional nystagmus, eye tracking, Mann or Stepping test in many of the patients. There were no remarkable histological alterations in the vestibular ganglion and nerve of the patients. Moderate and diffuse gliosis with slight shrinkage of neurons were observed in the vestibular and fastigial nuclei of all the patients. Slight loss of neurons in various vestibular nuclei was examined in only 4 patients. The fastigial nucleus showed no evident loss of neurons. In contrast, the cerebellum showed diffuse loss of Purkinje and granule cells, the degree of which was higher in the vermis than in the hemisphere and the flocculus. In the controls, the vestibular nerve and nuclei showed no remarkable alteration even in eight decade subjects. However, the Purkinje cells in the vermis seemed to have a tendency to decrease in aging. The dysequilibrium in the patient of methyl mercury intoxication did not seem to be correspond to the degeneration of the vestibular ganglion, nerve or nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Selective decrease of large neurons in the neostriatum in progressive supranuclear palsy.

In order to evaluate the quantitative changes in the neostriatum in progressive supranuclear palsy (PSP), sections of the caudate head (CN) and putamen (PT) from 4 PSP patients were stained with Klüver-Barrera, and the cell body and nuclear area of the neurons were measured by a digitizer. Obtained results were compared to those of 6 age-matched control and 4 Alzheimer's disease and senile dementia of Alzheimer type (AD/SDAT) subjects which were previously reported. The number of large neurons (nuclear area greater than 101 microns 2) in PSP was about 40% (P less than 0.01) and 30% (P less than 0.01) of that of the controls in CN and PT, respectively. In contrast, the number of small neurons in PSP (nuclear area less than 100 microns 2) was well preserved. The values were quite similar to those in AD/SDAT. The implications and possible significance are discussed.

Aged↗
PubMed1988

Cytoarchitectonic investigation of the rat spinal cord following ethylnitrosourea administration at different developmental stages.

We examined the histological findings and cytoarchitectonic alterations in the rat spinal cord following matrix cell degeneration caused at different developmental stages, from neural plate formation through neuroblast generation. Ethylnitrosourea (ENU) 20 mg/kg body weight was administered transplacentally to the fetuses on the 10th embryonic day (E10) to 14th. The observations were made until the 21st postnatal day. Normally, mitoses were present scatteredly in the matrix cell layer of the neural plate or neural tube on E10 or E11, and gradually restricted to the dorsal portion of the alar plate as development occurred. The localization and number of degenerative cells as well as the site and degree of neuronal decrease in the completed dysgenetic spinal cord seemed to correlate with the topography and frequency of the mitoses in the matrix cell layer at the time of ENU administration. Disorder in the pattern of cytoarchitecture of neurons was not observed. The degree of hypoplasia of the white matter was proportional to the intensity of decrease of the spinal neurons. Aberrant myelinated fibers were not seen. No reactive gliosis, fibrosis or abnormal vascularization was observed at any time.

Animals↗