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Biomedical subjects

E Satoyoshi

Publications and source records attributed to E Satoyoshi.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Positron emission tomography in two cases of transient global amnesia].

We encountered two cases of typical transient global amnesia (a 53-year-old woman and a 50-year-old man). Both cases showed no evidence of abnormal findings which caused the attack on examinations of CSF, EEG, brain CT, brain MRI and cerebral angiography. Examinations of positron emission tomography, using 15O labeled CO2 and O2, were performed on 14 and 8 days after the attack in the female and male cases, respectively, and those disclosed decreased regional blood flow (CBF), increased oxygen extraction ratio (OER), and decreased oxygen metabolic ratio (CMRO2) in the bilateral medial temporal and occipital lobes, which were supplied by the bilateral posterior cerebral arteries. PET, performed on about one month after the attack, revealed normalized values of CBF, OER, CMRO2 in both cases. These findings strongly suggested that transient global amnesia in our cases may be related to ischemia of the bilateral posterior cerebral arteries.

Amnesia↗
PubMed1988

Antibodies against saline-soluble components of skeletal muscle in myasthenia gravis.

Antibodies against phosphate-buffered-saline extracts (SE) of non-acetylcholine receptor (AChR) skeletal muscle antigens were found in patients with myasthenia gravis (MG). The antigenicity of SE was distributed in three fractions with molecular masses of over 200 kDa, 90-150 kDa and 7-14 kDa on gel filtration. These fractions shared common antigenicities. Further analysis of 90-150 kDa fractions on sodium dodecyl sulphate polyacrylamide gel electrophoresis showed five major bands, ranging from 105 kDa to 275 kDa. The antibodies against SE were detected in 52% (58/112) of the MG patients; incidence and titres were higher in the thymoma group (n = 21; 90% and 0.872 respectively) than in the non-thymoma group (n = 91; 43% and 0.200, P less than 0.001). In patients without a thymoma, these antibodies were frequently observed in late-onset disease and the severe generalized form (P less than 0.01). In 4 of 7 ocular MG patients without anti-AChR antibodies, low but appreciable levels of anti-SE antibodies were found. In 73% (11/15) of generalized MG patients treated with prednisolone and thymectomy, anti-SE antibody titres changed in association with those of anti-AChR antibodies and with the clinical course. Both antibody titres increased synchronously in patients who developed crises.

Adult↗
PubMed1987

Regulation of nerve growth factor synthesis/secretion by catecholamine in cultured mouse astroglial cells.

The nerve growth factor (NGF) synthesis/secretion by cultured mouse astroglial cells was modulated by catecholamine. In quiescent cells, epinephrine (EN) and dopamine (DA) markedly increased the NGF content in the conditioned medium (CM). Conversely, EN, DA, and norepinephrine (NE) decreased the NGF content in growing cells. Cholinergic agonists, metacholine and carbamylcholine, slightly increased the NGF content in quiescent cells, but showed no effects on growing cells. Other neurotransmitters tested had no effects on either growing or quiescent cells. These results suggest that catecholamine is one of the molecules responsible for regulation of NGF synthesis/secretion in the mouse brain.

Animals↗
PubMed1987

Synthesis/secretion of nerve growth factor is associated with cell growth in cultured mouse astroglial cells.

Astroglial cells cultured from 8-day-old mouse brain synthesized and secreted nerve growth factor (NGF). An increase in cell density or the withdrawal of serum from the culture medium caused a drastic decrease in the rate of NGF secretion which could be reversed by reculturing at a low cell density or by refeeding with serum-containing culture medium. The cells cultured for two weeks without serum entered the quiescent phase without loss of the activity of an astroglial marker enzyme, glutamine synthetase. These results suggest that NGF secretion by astroglial cells in vitro is regulated in a growth phase-dependent manner. Evidence is also presented to show that NGF secretion is not phase-specific in the cell cycle.

Animals↗
PubMed1986

Aliphatic side chain of catecholamine potentiates the stimulatory effect of the catechol part on the synthesis of nerve growth factor.

Catecholamines are potent in stimulating nerve growth factor (NGF) synthesis in mouse L-M cells. The relationship between the structure of catecholamines and their stimulatory effect on NGF synthesis has been studied using various 3,4-dihydroxyphenyl derivatives or their analogues. All 3,4-dihydroxyphenyl derivatives with two saturated carbons on the side chain were potent stimulators, whereas those with only one carbon on the side chain were weak stimulators. Drugs lacking the catechol ring were not effective. These results suggest that the catechol part of catecholamines is essential for the stimulatory effect and that the aliphatic side chain potentiates this effect. The present results also suggest the terminal amino residue on the side chain is not critical for the effect.

Animals↗
PubMed1986

An enzyme-linked immunosorbent assay for antibodies against saline-soluble muscle components in myasthenia gravis.

An enzyme-linked immunosorbent assay (ELISA) system has been developed for measuring antibodies against rat skeletal muscle components solubilized with phosphate-buffered saline. With this assay, 53.8% (50/93) of sera from patients with myasthenia gravis (MG) was positive (the values over the mean plus 3 SD of 256 healthy individuals were considered significant). No sera from patients with neurological disorders other than MG gave positive values (0%; 0/60). No correlation between titers of antibody against the muscle components and those of anti-acetylcholine receptor antibody (r = 0.01) was found. These results indicate that our ELISA system is useful for diagnosing myasthenia gravis.

Autoantibodies↗
PubMed1986

Catecholamines induce an increase in nerve growth factor content in the medium of mouse L-M cells.

L-M cells, a mouse fibroblast cell line, synthesized and secreted a nerve growth factor (NGF). The neurite outgrowth stimulatory activity, immunoreactivity, molecular weight, and isoelectric point of L-M cell NGF were identical to those of beta-NGF of the mouse submaxillary gland. Treatment of the cells with either norepinephrine or epinephrine in the range of 0.05-0.2 mM for 24 h resulted in a 3-20-fold increase in NGF content in the medium of the L-M cells. The NGF of epinephrine-treated cell was identical to that of control cell. The stimulation of the increase in NGF content was observed after a 4-h lag time. The rate of incorporation of [3H]leucine into trichloroacetic acid-insoluble materials was essentially unchanged during the treatment. These results suggested that norepinephrine and epinephrine stimulated the de novo synthesis and secretion of NGF protein. Evidence is also presented to indicate that the effects of the drugs are due to the catechol part of the molecule and not mediated by adrenergic receptors.

Animals↗
PubMed1986

Synthesis and secretion of nerve growth factor by mouse astroglial cells in culture.

Astroglial cells cultured from the mouse brain have been found to synthesize and secrete a material(s) with nerve growth factor-like immunoreactivity (NGF-LI) into their culture medium. A material(s) with NGF-LI showed identical properties to those of beta NGF purified from the mouse submaxillary gland in immunoreactivity, molecular weight, isoelectric point, and neurite outgrowth stimulatory activity. These results indicate that astroglial cells cultured from mouse brain are able to synthesize and secrete beta NGF in culture.

Animals↗
PubMed1986

A new syndrome of anosmia, ichthyosis, hypogonadism, and various neurological manifestations with deficiency of steroid sulfatase and arylsulfatase C.

We describe a family consisting of 3 affected men with congenital ichthyosis, anosmia, hypogonadism, nystagmus with decreased visual acuity, strabismus, hypopigmentation of the iris, and mirror movements of the hands and feet. Two of them had limitation of ocular movement and unilateral renal agenesis or hypoplasia. The condition appears to be inherited as an X-linked recessive trait. Clinical, pathological, and biochemical evaluations were compatible with a diagnosis of X-linked ichthyosis. Steroid sulfatase and arylsulfatase C activities in leukocytes and fibroblasts were markedly diminished in the affected patients. Their hypogonadism was due to decreased luteinizing hormone-releasing hormone secretion (hypogonadotropic). Hyposecretion of antidiuretic hormone was also recognized. Chromosome analysis of leukocytes and skin fibroblasts revealed a normal 46,XY male karyotype in all of the patients.

Adolescent↗
PubMed1986

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes with acanthocytosis: a clinicopathological study of a unique case.

A case of a unique combination of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like syndrome (MELAS) with acanthocytosis is reported. Neuropathological examination revealed pellagra-like change in Betz cells, brain-stem neurons and anterior horn cells as well as findings compatible with mitochondrial encephalomyopathies. Abnormal function of nicotinic acid-related enzymes could be the cause of the complicated clinicopathologic findings in this case. This is the first report of MELAS with acanthocytosis.

Acanthocytes↗
PubMed1986

Mitogenic heparin-binding lectin-like protein from cloned thymic myoid cells.

A mitogenic heparin-binding (reactive) lectin-like protein (HBP) was purified from the extract of a cloned rat thymic myoid cell R615B2 by a one-step procedure of affinity chromatography on a heparin--Sepharose CL-6B column. Four distinct peptide bands with molecular weights of 10,000, 13,000, 13,700, and 14,600 were detected on SDS-polyacrylamide gel electrophoresis. This protein is mitogenic at concentrations of as low as 1.1-70.0 ng/ml for peanut lectin-nonagglutinated thymocytes and splenocytes from euthymic mice and rats but not for splenocytes from nude mice. These results indicate that thymic myoid cell-derived HBP is an important signal for one particular step in T-cell differentiation.

Animals↗
PubMed1986

Ca content of human erythrocytes. What is the true value?

It has been generally accepted that the Ca content of washed erythrocytes is in the range of 1 - 3 X 10(-5) mole/l cells (1-10). These values were obtained after samples were treated in various way for Ca measurement. However, by using a simplified careful preparation technique to avoid Ca contamination together with inductively coupled argon plasma emission spectroscopy, we have found that the Ca content of erythrocytes washed with nominally Ca2+-free solution, is one order of magnitude lower than the reported values, in the range of 1 X 10(-6) moles/l cells.

Adolescent↗
PubMed1985

Kinetic studies on neurotoxin-binding inhibitory antibodies in myasthenia gravis.

A method for measuring antibodies which inhibit the binding of 125I-alpha-bungarotoxin to the acetylcholine receptor was developed. The procedure allows the detection of inhibitory activity in 70% of sera from the patients with myasthenia gravis. Kinetic analysis showed that (1) a linear dose-response exists between logarithmic concentrations of any test serum and inhibitory activity, (2) the slope of the inhibition line is identical among various myasthenic sera and, (3) the slope of line induced by various cholinergic ligands was comparable to that obtained by myasthenic sera. The inhibitory activity correlated with the titer of anti-acetylcholine receptor antibody measured by an immunoprecipitation method (r = 0.76, p less than 0.01).

Adolescent↗
PubMed1985

Effects of dimethylsulfoxide on sphingomyelinase in cultured human fibroblasts and correction of sphingomyelinase deficiency in fibroblasts from Niemann-Pick patients.

The effects of dimethylsulfoxide (DMSO) on sphingomyelinase activity were studied using human skin fibroblasts from normal individuals and Niemann-Pick patients. Sphingomyelinase activity in normal fibroblasts increased up to 230% of controls by 2% DMSO while the cell growth was inhibited. Other lysosomal hydrolases showed a rather smaller extent of increment in activity. There was no direct effect of DMSO in cell-free system and no evidence of any activating factor of sphingomyelinase in homogenates. Sphingomyelinase deficiency in fibroblasts from a Niemann-Pick patient (type C) was corrected by 2% DMSO with regaining its enzyme activity.

Cell Division↗
PubMed1985

Idiopathic dystonia-parkinsonism with marked diurnal fluctuation of symptoms.

Studies were performed on 5 patients with idiopathic dystonia-parkinsonism, each of whom had minor dystonic movements and parkinsonian symptoms with marked diurnal fluctuation. Levels of homovanillic acid and 5-hydroxyindoleacetic acid were not different from those in controls. Considerable improvement in dystonic movements and parkinsonian symptoms was obtained with a small dose of L-dopa, trihexyphenidyl hydrochloride, amantadine, or bromocriptine hydrochloride. Electrophysiological investigation confirmed that the dystonic movements, which became remarkably worsened on attempted movement, contributed importantly to the diurnal fluctuation of symptoms.

Adult↗