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Biomedical subjects

G Takada

Publications and source records attributed to G Takada.

At least 181 records · Page 10Linked to original sources
PubMed1989

Multiple populations of deleted mitochondrial DNA detected by a novel gene amplification method.

A gene amplification method for detecting small populations of deleted mitochondrial DNA was used in analysis of skeletal muscle from a patient with ocular myopathy. Multiple populations of differently deleted mtDNA were detected in the patient muscle. The presence of deleted mtDNAs was further confirmed by comparison of the shift in the sizes of the amplified fragments with the shift in the positions of the primers used for the amplification, (the primer shift PCR method). Other methods, namely Southern blotting, enzymic activity measurement, and Western blotting, were inefficient at detecting the mitochondrial abnormality. These findings suggest that the primer shift PCR method could be valuable for accurate diagnosis of ocular myopathy associated with mtDNA deletion.

Blotting, Western↗
PubMed1988

Effect of tetrahydrobiopterin and 5-hydroxytryptophan on hereditary progressive dystonia with marked diurnal fluctuation: a suggestion of the serotonergic system involvement.

A daughter and her mother developed hereditary progressive dystonia with marked diurnal fluctuation (HPD) at the age of 4 and 34, respectively. L-Dopa, tetrahydrobiopterin (BH4) or 5-hydroxytryptophan (5-HTP) was orally administered to them. L-Dopa cured completely their symptoms. 5-HTP as well as BH4 improved their symptoms, especially dystonic movements. Biopterin and 5-hydroxyindoleacetic acid concentrations in CSF increased during BH4 medication. These findings suggest that the serotonergic system of the central nervous system might play some role in the pathogenesis of dystonia in HPD.

5-Hydroxytryptophan↗
PubMed1987

Transitory type of sphingomyelinase deficient Niemann-Pick disease: clinical and morphological studies and follow-up of two sisters.

The transitory type is a rare and ill-defined variant of sphingomyelinase deficient NPD. Here reported are full clinical and morphological studies on two sisters with the transitory type. Our cases have the following features in common: 1) prominent visceral involvement from early infancy, such as marked hepatosplenomegaly, pulmonary infiltration, and numerous characteristic foam cells in the bone marrow aspirates; 2) very low sphingomyelinase activities in cultured skin fibroblasts; 3) atypical cherry-red spots in the retina; despite 4) absence of any neurological symptoms even at the age of 5 years and 6 months, and 3 years and 9 months, respectively. Furthermore, a few lines of evidence indicating nervous system involvement are also disclosed, that is, 5) vacuolated macrophages in the cerebrospinal fluid and ultrastructurally typical inclusion bodies in axons and Schwann cells in the rectal biopsy specimens, which were firstly revealed in this type of NPD. It is stressed that every case with apparent type B NPD should be searched for the presence or absence of neuronal involvement by not merely fundoscopy but other available means as we employed, which would greatly contribute to elucidate the clinico-pathogenetical knowledge not to mention the current classification of NPD.

Bone Marrow↗
PubMed1987

Carnitine deficiency in lysinuric protein intolerance: lysine-sparing effect of carnitine.

Plasma carnitine deficiency (41% of normal control) was found in a 9 year-old boy with lysinuric protein intolerance. Following oral carnitine administration, the plasma level of lysine as well as carnitine has significantly increased (p less than 0.05). His well-being seemed to have improved on this substitutive remedy. Hitherto unrevealed these findings on LPI indicate that carnitine has a lysine-sparing effect and suggest that there might be a biosynthetic pathway of carnitine directly from free lysine in human.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Human alpha-L-iduronidase. II. Comparative biochemical and immunologic properties of the purified low and high uptake forms.

The physicokinetic and immunologic properties of the purified low and high uptake forms of the human lysosomal hydrolase, alpha-L-iduronidase, have been determined and compared. The apparent Km and Vmax values for the low and high uptake forms were similar toward two artificial substrates, 4-methylumbelliferyl-alpha-L-iduronide (0.07 and 0.06 mmol/l; 16.15 and 14.85 mumol/min/mg, respectively), and phenyl-alpha-L-iduronide (1.42 and 1.66 mmol/l; 0.83 and 1.05 mumol/min/mg, respectively), and one natural substrate, anhydro-[3H]-mannitol-iduronide (0.86 and 1.04 mmol/l; 2.50 and 2.79 mumol/min/mg, respectively). The pH optima for both purified forms also were similar for each of the three substrates ( approximately 3.50, approximately 3.50, and approximately 4.50, respectively). Heparin markedly inhibited the 4-methylumbelliferyl-alpha-L-iduronide activities of both the low and high uptake forms, while dermatan sulfate and heparan sulfate were more inhibitory toward the low uptake activity. EDTA was a potent inhibitor of both enzyme forms; the divalent cations, Mg2+ and Ca2+, could recover up to 30% of the enzymatic activities after EDTA treatment. p-Chloromercuribenzoate and maleate also were inhibitory, whereas dithiothreitol and 2-mercaptoethanol were stimulatory. Both enzyme forms had similar thermostabilities ; the half-lives at 45, 52, and 60 degrees C were about 38, 24 and 12 min, respectively. The low and high uptake forms were immunologically cross-reactive as demonstrated by Ouchterlony double immunodiffusion and immunotitration studies using anti-human low uptake antibodies.

Endocytosis↗
PubMed1983

Microautoradiographic study on the tissue localization of liposome-entrapped or unentrapped 3H-labeled beta-galactosidase injected into rats.

The localization of intravenously injected liposome-entrapped or unentrapped 3H- beta-ga lactosidase in various tissues of rats was investigated by microautoradiography. The microautoradiographic silver grains, indicating the uptake of both forms of the enzyme were observed in all of the rat tissues studied, such as the liver, kidneys, spleen, lungs, heart, muscle and brain. The liver was found to be the most active in taking up both forms of the enzyme and probably Kupffer cells were primarily involved in the uptake of the enzyme. Also in the brain, the uptake of both forms of the enzyme was observed, though far less extensively, through the blood-brain barrier. The uptake of the enzyme in the brain was somewhat greater in the gray matter than in the white matter.

Animals↗
PubMed1982

Lymphoblasts and diagnosis of pyruvate carboxylase deficiency.

Pyruvate carboxylase activity was measured in phytohemagglutinin-transformed lymphocytes (i.e. lymphoblasts). Mean value +/- S.D. for 10 controls was 259 +/- 38 pmoles/min per mg protein. It was about 7 times higher than that of peripheral leukocytes and a half of cultured skin fibroblasts with similar techniques. Deficient pyruvate carboxylase activity less than 6 pmoles/min per mg protein was demonstrated in the lymphoblasts from a patient with biotin-dependent multiple carboxylase deficiency. It is suggested that lymphoblasts may allow more reliable and ready diagnosis of patients with pyruvate carboxylase deficiency.

Adult↗
PubMed1982

Delivery of fungal beta-galactosidase to rat brain by means of liposomes.

A significant increase in beta-galactosidase activity was observed in the brain of rats 1 hr after an intravenous injection of liposomes containing beta-galactosidase purified from Aspergillus oryzae. The increased activity was proved to have features of the fungal enzyme by differentiating it from rat's native beta-galactosidase in both heat stability and immunochemical studies. Blood content of rat brain tissue under the experimental conditions employed was estimated as 0.83% (v/w) from an infusion experiment of 131I-labeled human serum albumin. The net uptake of fungal beta-galactosidase by rat brain was calculated as equal to 10 micrograms protein of the fungal enzyme or 0.31% of the injected dose/g tissue, which gave rise to 4.4-fold net increase in enzyme activity above control levels. The experiments clearly demonstrated that liposome-entrapped fungal enzyme was allowed to penetrate the blood-brain barrier and to gain access to rat brain, suggesting liposomes as an effective carrier for exogenous enzyme delivering to the central nervous system of patient with inherited lysosomal storage diseases.

Animals↗
PubMed1982

Pyruvate decarboxylase deficiency in a patient with Leigh's encephalomyelopathy.

A 23-month-old boy with progressive muscular hypotonia and mental and motor deterioration was described. Four days after the admission he had a respiratory arrest and required the care in a respirator thereafter. Laboratory examinations showed metabolic acidosis and high levels of pyruvate, lactate and alanine in blood and cerebrospinal fluid. Oral administration of thiamine-HCl and lipoic acid was noneffective and he died 7 months after the admission. Autopsy findings were compatible with subacute necrotizing encephalomyelopathy (Leigh's disease). The activity of pyruvate decarboxylase in autopsy samples was not detectable and that in fibroblasts was 9% of that in control cell lines. The present study confirmed that pyruvate decarboxylase deficiency is one of the causes of Leigh's disease.

Brain↗
PubMed1981

Tissue distribution of unentrapped or liposome-entrapped 131I-labeled beta-galactosidase injected into rats.

Either unentrapped (free) or liposome-entrapped 131I-labeled beta-galactosidase was injected into rats from tail veins. Tissue distribution and intracellular localization of the radioactivity of both sources were compared. The half-life of liposome-entrapped enzyme in the circulation was much longer than that of the free enzyme. The radioactivity removed from the circulation was recovered primarily in the liver, and to a lesser extent in almost all tissues studied. A small but significant uptake of liposome-entrapped enzyme by the brain was also observed. Uptake of liposome-entrapped enzyme was greater thant that of free enzyme in the spleen, heart, lungs and brain, excepting the liver and kidneys. Subcellular fractionation showed distribution of the radioactivity of liposome-entrapped enzyme favoring the mitochondrial-lysosomal fraction from these tissues except the heart. There was a difference in the pattern of intracellular distribution of the radioactivity in the brain of rats between the administration of free enzyme and that of liposome-entrapped enzyme. These findings suggest that when liposomes containing beta-galactosidase were injected into rats from the tail veins, they would penetrate the blood-brain barrier and would reach the lysosomes in the central nervous system tissue more effectively than the free enzyme itself. Beta-galactosidase; liposome; enzyme replacement therapy; rat tissues, 131I.

Animals↗
PubMed1978

Congenital lactic acidosis due to pyruvate carboxylase deficiency: absence of an inhibitor of TPP-ATP phosphoryl transferase.

Two children are described who suffered from episodes of metabolic acidosis and progressive mental and motor deterioration. The patients showed periodic elevation of blood lactate, pyruvate and alanine, which was accompanied by vomiting, hypotonia or convulsions. The concentrations of lactate and pyruvate in cerebrospinal fluid were found to be increased. Liver biopsies revealed a decrease in pyruvate carboxylase activity and normal pyruvate decarboxylase activity. No inhibitor of TPP-ATP phosphoryl transferase was detected in urine from the patients. These findings suggest that congenital lactic acidosis due to pyruvate carboxylase deficiency is probably a different disease entity from Leigh's encephalomyelopathy. A possible mechanism of brain damage caused by a defect in pyruvate carboxylase is postulated.

Acidosis↗