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Biomedical subjects

T Orii

Publications and source records attributed to T Orii.

At least 325 records · Page 18Linked to original sources
PubMed1988

Immunoblot detection of enzyme proteins of peroxisomal beta-oxidation in fibroblasts, amniocytes, and chorionic villous cells. Possible marker for prenatal diagnosis of Zellweger's syndrome.

The amounts of enzyme proteins of peroxisomal beta-oxidation in fibroblasts and chorionic villous cells from infants with Zellweger syndrome and in fibroblasts, amniocytes, and chorionic villi from healthy controls were measured by immunoblot analysis. Immunoreactive proteins of peroxisomal acyl-CoA oxidase and 3-ketoacyl-CoA thiolase were absent in fibroblasts and chorionic villous cells from the patients, yet these enzyme proteins were present in fibroblasts, cultured amniocytes, and chorionic villi from the normal controls. These results show that immunoblot analysis of peroxisomal beta-oxidation enzymes in amniocytes and chorionic villous cells is of potential value for the prenatal detection of Zellweger syndrome.

Amnion↗
PubMed1988

Zellweger syndrome and a microdeletion of the proximal long arm of chromosome 7.

A 16-day-old girl with Zellweger syndrome and a chromosomal rearrangement, 46,XX,del(7)(q11.22q11.23), is reported. The diagnosis was confirmed by marked deficiencies of peroxisomal beta-oxidation enzymes and dihydroxyacetone phosphate acyltransferase activities in rectal cells and fibroblasts obtained by biopsy and in hepatic cells obtained at autopsy. This is the first report of Zellweger syndrome associated with a chromosomal arrangement, a microdeletion of chromosome 7. A tentative gene assignment to 7q11 is suggested.

Chromosome Banding↗
PubMed1988

Zellweger-like syndrome with detectable hepatic peroxisomes: a variant form of peroxisomal disorder.

A male infant with typical clinical and biochemical findings of Zellweger syndrome, but in whom hepatic peroxisomes were detected by electron microscopy, had profound hypotonia, hepatomegaly, typical facial appearance including large fontanelle and frontal bossing, convulsions, panaminoaciduria, and hyperammonemia. He died of liver failure at age 5 months. There were increased levels of very long chain fatty acids and trihydroxycoprostanic acid in serum, and increased excretion of dicarboxylic acids and tyrosine metabolites in the urine. Levels of peroxisomal enzymes, acyl coenzyme A oxidase, bifunctional protein, 3-ketoacyl coenzyme A thiolase, and dihydroxyacetone phosphate acyltransferase in the liver tissue from the patient were all deficient, findings consistent with Zellweger syndrome. However, immunocytochemical study and electron microscopic examination of the liver at autopsy revealed that hepatic peroxisomes were present at a level similar to that in a control subject. These observations suggest further heterogeneity in Zellweger syndrome and a different pathogenesis in this variant case.

Bile Acids and Salts↗
PubMed1988

Defect in biosynthesis of mitochondrial acetoacetyl-coenzyme A thiolase in cultured fibroblasts from a boy with 3-ketothiolase deficiency.

The etiology of 3-ketothiolase deficiency has been attributed to a defect of mitochondrial acetoacetyl-CoA thiolase because the acetoacetyl-CoA thiolase activity in related materials is not activated by K+, a property characteristic for this enzyme. We studied the enzyme protein and the biosynthesis of mitochondrial acetoacetyl-CoA thiolase, using cultured skin fibroblasts from a 5-yr-old boy with 3-ketothiolase deficiency. The following results were obtained. (a) Activation of acetoacetyl-CoA thiolase activity by K+ was nil; (b) The enzyme activity was not affected by treatment with the antibody against mitochondrial acetoacetyl-CoA thiolase; (c) A signal for mitochondrial acetoacetyl-CoA thiolase protein was not detected in the immunoblot analysis; and (d) Pulse-chase experiments of skin fibroblasts, using [35S]methionine, revealed no incorporation of radioactivity into this enzyme. Therefore, fibroblasts from this patient lacked mitochondrial acetoacetyl-CoA thiolase protein due to a defect in its biosynthesis.

Acetyl-CoA C-Acetyltransferase↗
PubMed1988

Biochemical and morphologic aspects of peroxisomes in the human rectal mucosa: diagnosis of Zellweger syndrome simplified by rectal biopsy.

Rectal mucosa biopsy specimens from five controls and three infants with Zellweger syndrome were investigated morphologically and biochemically to elucidate peroxisomal structure and functions in the human rectal mucosa and to develop a simple method for an early postnatal diagnosis of peroxisomal deficiency disorders. After the alkaline 3,3'-diaminobenzidine reaction, peroxisomes of the rectal mucosa from the controls could be identified, electron microscopically, but not light microscopically. However, they were strongly stained using an immunoenzyme technique applied to semi-thin Epon sections and then were clearly visible under the light microscope. However, no positive granules were observed in the specimens of infants with Zellweger syndrome, using either of the two staining techniques. On immunoblot analysis, immunoreactive proteins of peroxisomal acyl-CoA oxidase and 3-ketoacyl-CoA thiolase were present in rectal mucosae from the controls; however, these enzyme proteins were not detected in tissues from the patients. Activity of dihydroxyacetone phosphate acyltransferase was detectable in rectal mucosae from the controls, whereas in those from infants with Zellweger syndrome, the activity of this enzyme was greatly reduced. These observations indicate that the peroxisomal structure and multiple functions are present in the rectal mucosa and that rectal biopsy is of potential value for the early and less invasive detection of Zellweger syndrome and other peroxisomal disorders.

Biopsy↗
PubMed1987

Biosynthesis of membrane polypeptides of rat liver peroxisomes.

The biosynthesis of three major peroxisomal membrane polypeptides of rat liver was investigated. Total hepatic RNA extracted by the guanidinium/CsCl method from three control and three di(2-ethylhexyl)phthalate (a peroxisomal proliferator)-fed rats was translated in vitro in a rabbit reticulocyte lysate protein-synthesizing system. Translation products were immunoprecipitated by the antibodies against peroxisomal membrane polypeptides, subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis, and analyzed by fluorography. The in vitro translation products of 70, 26, and 22 kDa peroxisomal membrane polypeptides were apparently of the same size as the respective mature polypeptides. The ratio of translatable mRNA levels for the 70, 26, and 22 kDa polypeptides in di(2-ethylhexyl)phthalate-fed rats to those in control rats were 5.4, 11.4, and 2.7, respectively. The synthesis of these three polypeptides with the free polysome fraction from di(2-ethylhexyl)phthalate-fed rats was more active than that with the membrane-bound polysome fraction, whereas the synthesis of albumin with the free polysome fraction was 27% of that with the membrane-bound polysome fraction. These results indicate that the peroxisomal major membrane polypeptides are synthesized on free polysomes and transported to peroxisomal membrane without any apparent proteolytic processing, and that the induction of these polypeptides by administration of a peroxisomal proliferator corresponds well to the induction of the peroxisomal beta-oxidation enzymes. The data also support the idea that peroxisomes are organized from pre-existing peroxisomes.

Animals↗
PubMed1987

A case of glutaric aciduria type I with unique abnormalities in the cerebral CT findings.

A first Japanese case of glutaric aciduria type I (GA-I) was described. She was a 7-month-old girl presenting with poor head control, irritability and sleeplessness. The profile of urinary organic acids by gas chromatography mass spectrometry (GC/MS) suggesting GA-I were confirmed by no activity of glutaryl-CoA dehydrogenase in the fibroblasts. The cerebral computer tomography (CT) showed marked changes such as large fluid collections on bilateral frontotemporal regions and a slight enlargement of bilateral ventricles. The amounts of urinary glutarate excretion decreased after restriction of lysine and tryptophan in her diet and administration of carnitine improved the carnitine levels in blood and urine, while these were less effective for the neurological symptoms. On the other hand, oral administration of lioresal, an analogue of gamma-aminobutyrate (GABA), cleared her symptoms such as ill temper, irritability and sleeplessness dramatically, and the abnormalities of the CT examinations were not more deteriorative until 2 years of her age at least. The neurological manifestations of GA-I seemed to be affected by the unusual metabolism of GABA in the central nervous system.

Baclofen↗
PubMed1986

Renal effects of dichloroacetate in vivo.

We have investigated the effect of dichloroacetate (DCA) on the urinary excretion of lactate and pyruvate in a patient with congenital lactic acidosis and in healthy human controls. DCA administered orally in doses of 50 mg/kg and 30 mg/kg decreased plasma lactate and pyruvate of both the patient and the controls, while the urinary excretion of lactate and pyruvate was increased. However, these urinary increments were too small to contribute to the decrease of plasma lactate and pyruvate.

Acetates↗
PubMed1986

Deficient activities and proteins of peroxisomal beta-oxidation enzymes in infants with Zellweger syndrome.

The activities and amounts of enzyme proteins of peroxisomal beta-oxidation in Japanese children with Zellweger syndrome were investigated. Cyanide-insensitive fatty acid oxidation, peroxisomal enoyl-CoA hydratase and 3-oxoacyl-CoA thiolase activities were not detectable in liver tissue at autopsy, whereas the activities of mitochondrial enoyl-CoA hydratase, 3-oxoacyl-CoA thiolase and carnitine palmitoyltransferase were similar to those in the healthy controls. On immunoblot analysis, immunoreactive proteins of peroxisomal acyl-CoA oxidase, bifunctional protein and 3-oxoacyl-CoA thiolase were not detected in the livers, kidneys and fibroblasts from the patients. Proteins of catalase and some enzymes of mitochondrial fatty acid oxidation were similar as in normal controls. These data indicate that increased levels of very-long-chain fatty acids in Zellweger syndrome are due to the lack of the enzyme proteins of peroxisomal beta-oxidation.

Acetyl-CoA C-Acyltransferase↗