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Biomedical subjects

I Goto

Publications and source records attributed to I Goto.

At least 199 records · Page 11Linked to original sources

A nation-wide collaborative study on the long-term effects of bromocriptine in patients with Parkinson's disease. First interim report in Japan.

Two prospective projects were started in May 1985 to evaluate the long-term effects of bromocriptine in patients with Parkinson's disease. One of the projects is to see if combination therapy with levodopa and bromocriptine is superior to levodopa alone with regard to the prevention of late side effects of levodopa therapy. The other is to see the long-term effects of bromocriptine monotherapy. Patients with Parkinson's disease were allocated randomly to either combination or levodopa group in the first project. Parkinsonian symptoms, disabilities of daily life and severity of late side effects of long-term levodopa therapy were evaluated by a semiquantitative rating scale. This communication represents the first interim report. Methods of the studies and synopsis of the results at the end of the 12th month are described. A total of 702 patients was enrolled in the study (combination therapy, n = 216; levodopa therapy, n = 200, bromocriptine monotherapy, n = 286). At the end of the 12th month, the numbers of patients who dropped out from the study were 19, 16 and 55 in the three groups, respectively. It appears to be too early to make any definite conclusion with regard to which mode of treatment is superior, however, some evidence suggesting a superiority of the combination therapy over levodopa alone was noted in managing wearing-off phenomenon and dyskinesia. As many patients are sticking to the originally intended mode of treatment, it appears to be possible to obtain more meaningful data in several years.

Adult↗

Complementary DNA for the mouse homolog of the human amyloid beta protein precursor.

The human amyloid beta protein is a major component of brain amyloid found in patients with Alzheimer's disease. As an initial step to understand the biological function of its precursor protein, we have isolated cDNA for the mouse homolog of the human beta protein precursor. Comparison of the predicted amino acid sequence with that of human revealed a quite high degree of homology (96.8%), and the calculated evolutionary rate of the mRNA at amino acid substitution site was relatively low (0.1 x 10(-9)/site/year). The mRNA was abundant in brain and kidney, and also detected in other tissues at low level. These results indicated that this protein is highly conserved through mammalian evolution and may be involved in a basic biological process(es).

Amino Acid Sequence↗

Hydrolysis of galactosylsphingosine and lactosylsphingosine by beta-galactosidases in human brain and cultured fibroblasts.

Enzymatic properties of beta-galactosidases with galactosylsphingosine (psychosine) and lactosylsphingosine as the substrates were examined. Although bile salts were stimulatory on the hydrolysis of the glycolipids in normal brain and cultured fibroblasts, the hydrolytic activities could be readily assayed, without detergents. The in vitro hydrolysis of lactosylsphingosine in cultured fibroblast homogenates was catalyzed by two enzymes, as is the case with the hydrolysis of galactosylceramide and lactosylceramide. Lactosylsphingosine beta-galactosidase activities assayed in the absence and the presence of taurocholate (probably lactosylceramidase I) were deficient in fibroblasts from patients with globoid cell leukodystrophy, while the activity assayed with sodium cholate (probably lactosylceramidase II) was deficient in GM1 gangliosidosis fibroblasts. In contrast, galactosylsphingosine beta-galactosidase was not activated by cholate and the enzyme activities assayed with the no-additive and taurocholate systems were deficient in brain and fibroblasts from patients with globoid cell leukodystrophy, thereby indicating that the hydrolysis of galactosylsphingosine is catalyzed by one enzyme, galactosylceramidase I. Exogenous lipids and an activator protein purified from normal spleen activated galactosylsphingosine beta-galactosidase but they were inhibitory to lactosylsphingosine beta-galactosidase. Because the Km values of lactosylsphingosine beta-galactosidase assayed with cholate were several magnitude higher than those obtained with the no-additive system and because lactosylsphingosine is readily hydrolyzed with the no-additive system in vitro, it is likely that the in vivo hydrolysis of the lipid is catalyzed by only one enzyme, lactosylceramidase I.

Bile Acids and Salts↗

Globoid cell leukodystrophy is a generalized galactosylsphingosine (psychosine) storage disease.

Galactosylsphingosine (psychosine) in somatic organs from a patient with globoid cell leukodystrophy and from the twitcher mouse, an animal model of human globoid cell leukodystrophy was assayed. There was an abnormal accumulation of galactosylsphingosine as in nervous tissues, albeit the concentrations being lower than those in nervous tissues. Galactosylsphingosine accumulation in the kidney of the twitcher mouse increased with age. These findings indicate that globoid cell leukodystrophy is a generalized galactosylsphingosine storage disease.

Age Factors↗

Clinical improvement after administration of coenzyme Q10 in a patient with mitochondrial encephalomyopathy.

In a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes [MELAS] who had normal mitochondrial enzyme activity, high doses of coenzyme Q10 (CoQ) were administered. Clinical improvement with decreased serum lactate and pyruvate levels was observed. Though the mechanism of action of CoQ is not known, a trial is worthwhile in patients with MELAS.

Acidosis, Lactic↗

Formalin fixed brains are useful for magnetic resonance imaging (MRI) study.

We carried out magnetic resonance imaging (MRI) studies on human brains which had been fixed in formalin solution for over 2 years and had been proven neuropathologically to be cases of multiple sclerosis (MS), progressive multifocal leukoencephalopathy (PML), and Balo's concentric sclerosis (Balo). Using spin echo (SE) and inversion recovery (IR) pulse sequences to detect demyelinated lesions in a living person with MS, the demyelinated lesions of the fixed brains in cases of MS, PML and Balo definitely re-appeared, although T1 and T2 in the gray and white matter were reduced following fixation. High signal areas on the SE images corresponded not only to the characteristic distribution of demyelinated lesions in the white matter but also to sparse myelin, gliosis and mild perivascular cuffing in the white matter around the demyelinated foci in cases of the fixed MS, PML and Balo brains. On the IR images, only MS plaques were evident. This MRI study of fixed brains proved useful to elucidate clinicopathological correlations.

Adolescent↗

Effects of methylcobalamin on vitamin B1- and B-deficient encephalopathy in rats.

Vitamin B1- and B-deficient encephalopathy was produced in adult Wistar rats and the effect of methylcobalamin was studied. These experiments were performed in vitamin B1- or B-deficient rats with or without the administration of guanidine, a magnesium antagonist. These encephalopathic rats showed symmetrical lesions in the pontine tegmentum. No pathological changes in the brainstem were seen in guanidine-administered rats. This suggests that guanidine itself doesn't produce these brainstem lesions. Moderate to severe pathological changes occurred in vitamin B-deficient rats with guanidine administration, whereas these pathological changes were milder in vitamin B1-deficient rats with guanidine administration and in vitamin B1- and B-deficient rats with the combination of the guanidine and methylcobalamin administrations. These facts suggest that vitamin B12, methylcobalamin, plays an important preventive role in the development of the pontine lesions in this experiment.

Animals↗

Surface phenotypic changes of spleen cells on acquisition of encephalitogenicity.

The relationship between surface marker expression and encephalitogenicity of spleen cells was studied in Lewis rats. Donors were sensitized with either BP/CFA or BP/IFA, or given BP-cultured naive spleen cells. The adoptive transfer of EAE was successfully achieved in every case after culture with BP, although only spleen cells from BP/CFA-sensitized rats proliferated significantly in response to BP. The observed encephalitogenicities were BP/CFA-sensitized cells greater than BP/IFA-sensitized cells much greater than cells from recipients of BP-cultured naive cells in descending order. In BP/CFA-sensitized cells, the expression of both W3/25 and OX-3 antigens on T cells increased markedly after culture with BP, but the expression of neither OX-19 nor OX-8 antigen increased significantly. Cells from neither BP/IFA-sensitized rats nor recipients of BP-cultured naive cells showed a significant change in the surface marker expression after culture with BP. Therefore, the generation of T cells coexpressing large amounts of both W3/25 and OX-3 antigens after culture with BP seems to correspond to the acquisition of the strong encephalitogenicity in vivo.

Animals↗

Accumulation of galactosylsphingosine (psychosine) in the twitcher mouse: determination by HPLC.

We developed a sensitive and simple procedure for determination of galactosylsphingosine (psychosine), using HPLC. The method involved extraction of lipids, separation by cation-exchange and C18 reverse-phase columns, and derivatization with o-phthalaldehyde. The fluorescent galactosylsphingosine was detected by HPLC. The amount of galactosylsphingosine was accurately assayed by simultaneous determination of glucosylsphingosine, as the internal standard. The detection limit was 0.5 ng/assay tube, and the quantitative range of the method was up to 750 ng. This procedure was applied to tissue from the twitcher mouse, an animal model of human globoid cell leukodystrophy, as well as tissue from normal and carrier mice. In the latter mice, a small amount of galactosylsphingosine was detected in the spinal cord (21.6-37.2 ng/100 mg wet weight) but not in the cerebrum and sciatic nerve. Marked accumulation of galactosylsphingosine was noted in the nervous tissues of the twitcher strain, even on postnatal day 4. The concentration of galactosylsphingosine was greater in the peripheral than in central nervous tissues. The spinal cord and brainstem contained more galactosylsphingosine than did the cerebrum and cerebellum. The concentration increased with age from 764 ng/100 mg in the sciatic nerve at 4 days to 5,910 ng/100 mg at 37 days. These data correlate well with the pathological changes; tissues containing higher concentrations of galactosylsphingosine show earlier and more severe pathological changes than those containing lower concentrations, thereby indicating the close link of galactosylsphingosine to the pathogenesis of the twitcher mouse.

Animals↗

Positron emission tomography in cases of chorea with different underlying diseases.

Local cerebral metabolic rate for glucose (LCMRglc) was measured with positron emission tomography using the 18F-fluorodeoxy-glucose method in five patients with chorea due to different underlying diseases. Hypometabolism was observed in the striatum bilaterally in patients with Huntington's disease, choreoacanthocytosis, sporadic progressive chorea and dementia, and pseudo-Huntington form of dentato-rubro-pallido-luysian atrophy (DRPLA). The patient with hemichorea showed hypometabolism in the striatum on the contralateral side to the chorea. The patient with pseudo-Huntington form of DRPLA showed a diffusely decreased LCMRglc in other structures including the cerebral cortex, thalamus and cerebellum. These findings indicated that dysfunction of the striatum is relevant to the genesis of chorea in all these patients, even though the extent of dysfunction in other structures is different in each case.

Adult↗

Biochemical studies in mitochondrial encephalomyopathy.

The alpha-keto acid dehydrogenase complex and its component enzymes, lactate dehydrogenase, pyruvate carboxylase, cytochrome c oxidase, succinate-cytochrome c reductase, NADH-cytochrome c reductase, and the concentration of cytochromes and enzymes of beta-oxidation in muscle from a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes were studied and no specific defect was found. These results raise the possibility that the mitochondrial changes in the patient may be secondary.

Acidosis, Lactic↗