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K Oyanagi

Publications and source records attributed to K Oyanagi.

At least 73 records · Page 4Linked to original sources
PubMed1993

Activation of human lysosomal sialidase.

An acid sialidase [EC 3.2.1.18], partially purified from human placenta by Con A-Sepharose adsorption and p-aminophenyl thio-beta-D-galactoside-CH-Sepharose (PATG-Sepharose) affinity chromatographies, was activated by incubation at 37 degrees C. This activation showed both time and temperature dependencies, with the most effective activation observed at 37 degrees C in the pH range between 4.3 and 5.2. The influence of various protease inhibitors on its activation was investigated. Among the protease inhibitors tested, amastatin, an inhibitor of aminopeptidase A, significantly inhibited activation. The partially purified enzyme preparation contained aminopeptidase activity, which was inhibited by amastatin. Zinc ions inhibited either the activation of sialidase or the aminopeptidase activity in the enzyme preparation. These results suggest the possibility of participation of aminopeptidase function in the activation process of sialidase.

Aminopeptidases↗
PubMed1993

Conjunctival biopsy in adult form galactosialidosis.

Conjunctival biopsy was performed in two siblings with adult-form galactosialidosis. Electron microscopically, several types of intracytoplasmic inclusion were observed in the fibroblasts in conjunctival stroma, lymphatic capillary endothelial cells, Schwann cells, and epithelial cells. Membrane-bound vesicles with fibrillogranular content were frequently observed, and occasional lamellar structures were noted in these inclusions. Dense granular inclusions and oil droplets were also seen. Dense granular inclusions have not been reported in this disease previously.

Adult↗
PubMed1993

[Incidental occurrence of Lewy bodies in the brains of elderly patients--the relevance to aging and Parkinson's disease].

The Lewy body (LB) is a cytoplasmic neuronal inclusion that is constantly found in the substantia nigra and locus ceruleus, and other specific brain regions in Parkinson's disease (PD). In the present study, the significance of non-parkinsonian cases in which the LBs were an incidental finding was investigated. In 1,452 autopsy series (age range, 1-89 years), 27 incidental cases of LBs and 21 patients with PD were found. The age-specific prevalence of incidental LBs steadily increased from 0.7% to 6.5% between the sixth and ninth decades. The distribution of LBs in incidental cases was similar to that in PD. The number of neurons in the substantia nigra and locus ceruleus was determined in 8 incidental cases (age range, 60-81 years), 9 patients with PD (range, 56-81 years) and 9 control subjects (range, 60-81 years). In incidental cases, the average numbers of pigmented neurons in the substantia nigra and locus ceruleus was 83% and 77% of those in control subjects, respectively. In PD, the average numbers of pigmented neurons in the substantia nigra and locus ceruleus was 28% and 19% those of controls, respectively. However, the number of nonpigmented neurons in the substantia nigra was not reduced in incidental cases and PD. From the above findings, it is suggested that there exists a close relationship between the occurrence of LBs and aging. However, in the brains of elderly patients, incidental LBs were considered to be pathological findings rather than simple aging phenomenon. Therefore, it has been suggested that incidental cases may represent early and presymptomatic cases of PD.

Adolescent↗
PubMed1993

[The aging of central nervous system in methylmercury intoxication in Niigata, Japan--quantitative investigation of neurofibrillary tangles and senile plaques].

In order to elucidate the progression of aging process in the brains of methylmercury intoxication in humans, neurofibrillary tangles (NFT) and senile plaques (SP) were examined quantitatively in the temporal lobe and calcarine cortex of 16 patients with methylmercury intoxication and 12 control subjects by using tau and beta-peptide immunostained preparations. The numbers of NFT and SP in the patients of methylmercury intoxication were almost equal to those in control subjects, and statistically there is no significant difference. The findings indicate that the methylmercury intoxication in humans does not induce or exacerbate the NFT or SP forming disease process at least in these regions in the brain.

Aged↗
PubMed1992

Does methylmercury intoxication induce arteriosclerosis in humans? A pathological investigation of 22 autopsy cases in Niigata, Japan.

In order to clarify whether or not arterio- and/or arteriolosclerosis is induced or exacerbated in patients with methylmercury (Me-Hg) intoxication, the pathological features of arteries and arterioles in specific areas in 22 patients and 36 control subjects were examined qualitatively and quantitatively. Vessels investigated were: (1) small arteries and arterioles in the subarachnoid space and cortex of the postcentral gyrus, transverse temporal gyrus, first visual area and cerebellar vermis, as well as the myocardium and renal cortex; (2) the lateral striate artery; (3) the internal carotid, anterior, middle and posterior cerebral, basilar and vertebral arteries, as well as the coronary and renal arteries; and (4) the aorta. The arteriosclerotic changes observed in the patients with Me-Hg intoxication were indistinguishable both qualitatively and quantitatively from those of controls. The results indicate that Me-Hg intoxication does not induce or exacerbate sclerotic changes in arteries and arterioles. Thus, the peculiar neurological symptoms and neuropathological features of Me-Hg intoxication are thought to be induced not by ischemia but by selective primary degeneration of the neurons in specific regions.

Adult↗
PubMed1992

Clarke's column in sporadic amyotrophic lateral sclerosis.

Histological, ultrastructural and morphometrical observations on Clarke's column were carried out in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 15 age-matched control subjects. Of the 18 ALS patients 6 had been on a respirator before death. Bunina bodies were found in the neuronal cytoplasm in 7 of the 12 non-respirator-supported ALS patients and in 3 of the 6 respirator-supported patients. The number of spheroids was significantly higher in the non-respirator-supported patients (P < 0.01) than in the control subjects; however, the number in the respirator-supported patients was about equal to that in the controls. The number of neurons in Clarke's column in the non-respirator-supported ALS patients was not reduced, but in the respirator-supported patients they tended to disappear with time after respiratory support. These findings suggest that Clarke's column neurons are also involved primarily in the disease process in sporadic ALS. However, they may begin to disappear only after the patients require respiratory support.

Adult↗
PubMed1992

Syringomyelia. A neuropathological study of 18 autopsy cases.

Eighteen autopsy cases of syringomyelia were studied neuropathologically. In six cases associated with Chiari II malformation, the central canal was patent from the fourth ventricle to the syrinx, and the syrinx was simply a dilated central canal. In four cases associated with Chiari I malformation, the syrinx was irregularly shaped and communicated with the subarachnoid space at the entry zone of the posterior nerve roots. In six cases associated with spinal cord or posterior fossa tumors, the syrinx was located adjacent to the tumor tissues, and occupied the medullary gray matter or the spinal intermediate zone and the ventral part of the posterior horn. With regard to the pathogenesis of syringomyelia, we concluded that in cases associated with Chiari II malformation, vermian protrusion and direct continuity between the fourth ventricle and the syrinx were essential. In cases associated with Chiari I malformation, in addition to tonsillar protrusion, communication between the syrinx and the subarachnoid space was thought to play an important role, and in cases associated with tumors, the circulatory disturbance due to the presence of the tumors caused the syrinx.

Aged↗
PubMed1991

Retrospective survey of urea cycle disorders: Part 2. Neurological outcome in forty-nine Japanese patients with urea cycle enzymopathies.

We analyzed neurological data, including DQ or IQ, EEG, and CT scan, in 49 patients with urea cycle enzymopathies, all of whom were included in a retrospective survey from 1978-1988 in Japan. We classified 3 groups depending on age-at-onset: group 1 (0-28 days, N = 11), group 2 (29 days-5 years, N = 31), and group 3 (greater than 5 years, N = 7). The least DQ or IQ score and the highest CT score, representing the most severe brain damage was found in group 1, and the highest DQ or IQ and the least CT score was found in group 3. Intermediate scores of both parameters were found in group 2. There was a negative correlation between these 2 parameters (r = -0.82, P less than 0.01). Abnormal EEG during the attack-free period was predominantly observed in patients with CT abnormalities compared to those with a normal CT scan (P less than 0.01). Approximately 40% of the patients, mostly in groups 2 and 3 (92.8%) had normal findings in all 3 parameters. Thus, the magnitude of developmental abnormalities is clearly related to the degree of brain damage and to the age-at-onset of these diseases.

Brain↗
PubMed1991

Large neurons in the neostriatum in Alzheimer's disease and progressive supranuclear palsy: a topographic, histologic and ultrastructural investigation.

Large neurons in the neostriatum of patients with Alzheimer's disease (AD) and progressive supranuclear palsy (PSP) were investigated topographically, histologically and ultrastructurally. The number of large neurons whose nuclear area is greater than 101 microns2 was uniformly decreased in the neostriatum in PSP, but the decrease of these neurons in AD appeared to be more marked in the nucleus accumbens. Most of the remaining large neurons in both diseases contained neurofibrillary tangles (NFTs). In addition, some of the small neurons in PSP were positive for tau-immunostaining. Curly fibers were frequently observed in AD, but were absent in PSP. Ultrastructurally, NFTs in AD were composed mainly of paired helical filaments, whereas those in PSP contained straight tubules.

Aged↗
PubMed1991

Late-infantile type galactosialidosis. Histopathology of the retina and optic nerve.

We studied histopathologic findings from the retina and optic nerve of a patient with the late-infantile type of galactosialidosis and related them to clinical features of the condition. Markedly fewer ganglion cells were evident histopathologically using light microscopy. Results of histochemical studies demonstrated abnormal accumulation of lipid and proteinaceous material in the residual swollen ganglion cells. Marked loss of myelinated nerve fibers and thickening of the pial septum were also observed in the optic nerve. Both retinal ganglion cells and amacrine cells had intracytoplasmic inclusion bodies, but none were found in the optic nerve. These findings suggested that optic atrophy was induced by axonal wallerian degeneration secondary to retinal ganglion cell death. Although the fundus showed advanced optic nerve atrophy, a cherry red spot was not evident, possibly because of the marked decrease in ganglion cells in this case.

Adolescent↗
PubMed1991

Retrospective survey of urea cycle disorders: Part 1. Clinical and laboratory observations of thirty-two Japanese male patients with ornithine transcarbamylase deficiency.

In a retrospective survey done from 1978-1988 in Japan, 32 male patients with ornithine transcarbamylase (OTC) deficiency were identified. We classified a neonatal and 2 late-onset groups, depending on clinical manifestations and the age at onset; group 1 (0-28 days; N = 10), group 2 (29 days-5 years; N = 13), and group 3 (greater than 5 years; N = 9). Compared to findings in the group 2 patients, there was a higher rate of mortality and a higher incidence of mental retardation in association with a great decrease in enzyme activity in group 1. In group 3, the mortality rate and enzyme activities were similar to those in group 1. However, patients in this group were asymptomatic prior to the first episode. Enzyme activities were measured mostly in autopsy samples. The serum citrulline levels (enzyme product) were highest in this group. Thus, the mutant enzymes were apparently labile with greater activities in vivo than in vitro. Treatments, including a protein-restricted diet, arginine supplementation, and sodium benzoate administration, resulted in a favorable prognosis for survivors with partial enzyme deficiency. We wish to emphasize that the incidence of late onset of this disease is higher than heretofore considered.

Child, Preschool↗
PubMed1991

Galactosialidosis: neuropathological findings in a case of the late-infantile type.

The neuropathological findings in a 13-year-old Japanese male showing decrease of sialidase and beta-galactosidase activities are reported. The patient was the product of normal pregnancy to consanguineous parents. He started to sit at 8 months, stand at 20 months and walk at age of 2; mental retardation, visual disturbance, cerebellar ataxia, myoclonus and epilepsy developed by the age of 10, and he died at 13. Neuropathological investigation revealed neuronal loss and storage. Severe loss of neurons was observed in the thalamus, globus pallidus, lateral geniculate body, gracile nucleus, Purkinje and retinal ganglion cells. Marked ballooning was seen in the Betz cells and neurons in the basal forebrain, the motor neurons in the cranial nerve nuclei and spinal cord, and in the trigeminal and spinal ganglia. The storage material varied in staining from region to region and from neuron to neuron. Electron microscopic investigation revealed a variety of intracytoplasmic and intranuclear inclusions: membranous cytoplasmic bodies, parallel, wavy-lamellar or tortuous tubular structures, lipofuscin-like irregular-shaped pleomorphic bodies, and cytoplasmic vacuoles with fine granules and lamellar materials. The severity of the neuronal loss did not seem to correlate with the amount of the storage materials, but with the presence of tortuous tubular inclusion.

Brain↗
PubMed1991

Construction of spinal cord cDNA library and application for subtractive cloning of spinal cord-specific cDNAs.

Neurodegenerative diseases are characterized by neuronal degeneration of specific neurons, e.g., degeneration of motoneurons in amyotrophic lateral sclerosis. As an approach to understand molecular mechanisms of neuronal degeneration of human spinal cord motoneurons in various motor neuron diseases, we have constructed a human spinal cord cDNA library and developed a strategy for isolating spinal cord-specific genes by subtractive cloning. We constructed human spinal cord and brain cDNA libraries from postmortem human spinal cord and brain. To isolate human spinal cord-specific cDNAs, a spinal cord-enriched [32P]cDNA probe was generated by the phenol emulsion reassociation technique. Forty-eight cDNA clones out of 10,000 colonies gave strong signals with the subtracted probe, and individual spinal cord cDNA clones were isolated. Northern blotting analysis confirmed that two spinal cord cDNA clones are, in fact, more abundant in spinal cord compared to brain.

Blotting, Northern↗
PubMed1991

A nationwide survey on transient hyperammonemia in newborn infants in Japan: prognosis of life and neurological outcome.

A nationwide survey of transient hyperammonemia in newborns was carried out in Japan. A total of 18 patients, consisting of 12 male and 6 female infants, were reported from 11 facilities. These neonates exhibited hyperammonemia with plasma ammonia levels in the range from 124 to 6256 micrograms/dl. Four newborn infants of the 18 died in the neonatal period, and an additional one died in the early infancy. Among the 13 infants who were alive at the time of this survey, 6 had neurological sequelae, including mental retardation, spastic quadriplegia and epilepsy. The multivariate analysis revealed that the Apgar score at 1 minute, peak plasma ammonia concentration, birth weight and sex were significant factors affecting the prognosis of life.

Ammonia↗
PubMed1990

Lewy bodies in the lower sacral parasympathetic neurons of a patient with Parkinson's disease.

Lewy bodies were observed incidentally in the neurons of the dorsal group of nucleus intermediolateralis of the 3rd sacral segment of the spinal cord in a 74-year-old male with Parkinson's disease. The findings indicate the degeneration of the preganglionic parasympathetic neurons innervating the internal anal sphincter. The correlation between the findings and the mechanism of constipation in this disease are discussed.

Aged↗