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Biomedical subjects

K Oyanagi

Publications and source records attributed to K Oyanagi.

14 recordsLinked to original sources
PubMed1979

Neuraminidase activity in liver and brain from patients with I-cell disease.

The activity of neuraminidase in liver and brain from I-cell disease (Mucolipidosis II) was investigated. Neuraminidase activities using two substrates [alpha-L-N-acetylneuraminosyl(2 leads to 3)lactose and alpha-L-N-acetylneuraminosyl(2 leads to 6)lactose] were reduced in the supernatant and sedimentable fractions obtained in isotonic KCl. The activity of beta-D-galactosidase was also reduced in the liver; on the other hand, both neuraminidase fractions were normal, although beta-galactosidase activities were markedly reduced. In view of these results, it is suggested that the defect of neuraminidase is not directly responsible for the primary etiology of I-cell disease.

Brain↗
PubMed1979

Identification of keratan sulfate in liver affected by Morquio syndrome.

Glycosaminoglycan content, composition and molecular weight were determined in liver obtained from a patient with Morquio syndrome (Mucopolysaccharidosis IV). There was about a four-fold increase in glycosaminoglycan content (as hexosamine) of the affected liver as compared to the control liver. The major glycosaminoglycan accumulated in the liver was keratan sulfate, which was not found in the control liver. Chondroitin sulfates, especially chondroitin 6-sulfate, were also increased. Heparan sulfate isolated from the liver of a patient with Morquio syndrome was structurally different to that from control liver, and the glycosaminoglycans from Morquio syndrome were of a much lower molecular weight than those from control.

Adolescent↗
PubMed1979

Sphingomyelinase activities in cultured skin fibroblasts from patients with Niemann-Pick Disease.

Sphingomyelinase activity in cultured skin fibroblasts from a fetus affected with infantile-type Niemann-Pick disease was 0.5% of control activity; the activities in cells from two patients with adult-type disease (Cases 2 and 3) were 5.0% and 59.0%. Sphingomyelinase activiy was separated into three peaks (I-III) by isoelectric focusing. The isoelectric points were 4.5, 4.9, and 5.2 for peaks I, II, and III, respectively. The three peaks in the Case 2 cells were drastically reduced; only a very small peak could be distinguished (pI of 4.7). On the other hand, three peaks were observed in the Case 3 cells. Peak I had a pI of 4.4, peak II a pI of 4.7, and peak III a pI of 5.2. Peak I was found at near normal level, but both peaks II and III were markedly reduced. Sphingomyelinase in the peak I fraction obtained from isoelectric focusing in Case 3 cells was found to have the same Km value as that in control cells.

Adult↗
PubMed1979

Dubin-Johnson syndrome in a neonate.

We described the clinical and biochemical findings in a 32 day-old boy with the Dubin-Johnson syndrome. Only two other patients diagnosed as having the Dubin-Johnson syndrome during neonatal period have been reported in the literature. The ratio of urinary coproporphyrin isomer I of our patient was 97% and that of his parents were carrier level, confirming that increased urinary excretion of coproporphyrin isomer I is of diagnostic value in neonates with the Dubin-Johnson syndrome.

Coproporphyrins↗
PubMed1979

Age-dependent variations of lysosomal enzymes in human liver.

The specific activities, the Km values, and the elution patterns on DEAE 52 and Sephadex G-150 columns of six lysosomal enzymes in human liver during development were studied. The levels of total beta-D-glucuronidase and N-acetyl-beta-D-glucosaminidase activities in childhood liver were higher than those in fetal liver. The Km values of beta-D-glucuronidase and beta-D-galactosidase in fetal liver were about ten times higher than those in childhood liver. The elution patterns on DEAE 52 of beta-D-glucuronidase and on Sephadex G-150 of alpha-D- and beta-D-galactosidases changed with aging. It is suggested that lysosomal enzymes related to degradation of gangliosides and glycosaminoglycans change during development.

Acetylglucosaminidase↗
PubMed1978

Lysosomal acid hydrolases in established lymphoblastoid cell lines, transformed by Epstein-Barr virus, from patients with genetic lysosomal storage diseases.

Lysosomal acid hydrolases were determined in established lymphoblastoid cell lines, transformed in vitro by Epstein-Barr virus (EBV) from lymphocyte-rich cell populations isolated from the peripheral blood of patients with genetic lysosomal storage diseases--Hurler syndrome, Scheie syndrome, GM1-gangliosidosis type 1 and type 2, Tay-Sachs disease, and I-cell disease--and from obligate heterozygotes for these diseases. The respective enzyme activity was undectectable in lymphoblastoid cells from the patients, but not from controls. Obligate heterozygotes could not always be distinguished from controls in lymphoblastoid cells as well as in leukocytes. These results suggest that established lymphoblastoid cell lines are useful material for the enzymatic study of genetic lysosomal storage diseases.

Cell Line↗
PubMed1978

Chronic Niemann-Pick disease with sphingomyelinase deficiency in two brothers with mental retardation.

Clinical, biochemical, and electron microscopic studies are presented in two brothers with Niemann-Pick disease. The clinical features include hepatosplenomegaly and mental retardation without any other neurological signs. Roentgenograms of the chest showed bilateral diffuse reticular infiltration. The amounts of sphingomyelin and cholesterol in liver were increased, and sphingomyelinase activities in both liver and skin fibroblasts were markedly reduced in Case 1. Numerous foam cells and myelin figures were observed in the liver, kidneys, bone marrow, and lymph nodes on electron microscopical examination. These cases were regarded as a variant of Niemann-Pick disease from our investigations as they have mental retardation as an exceptional symptom when they are diagnosed as type B.

Adolescent↗
PubMed1977

alpha-L-Iduronidase activity in established lymphoblastoid cells from patients with Hurler and Scheie syndromes transformed by Epstein-Barr virus.

alpha-L-Iduronidase activity was determined in established lymphoblastoid cells, which were transformed in vitro by Epstein-Barr virus, of lymphocytes-rich cell populations isolated from peripheral blood of patients with Hurler and Scheie syndromes. alpha-L-Iduronidase activities in established lymphoblastoid cells from patients were undetectable, while activities of control subjects were clearly detected. These results suggest that established lymphoblastoid cells are useful for the enzymatic study of genetic mucopolysaccharidoses.

Adolescent↗
PubMed1976

Clinical and biochemical studies on periodic hyperammonemia with hyperlysinemia and homocitrullinuria.

An 18-year-old mentally and physically retarded boy, suffering from episodes of anorexia, vomiting, coma and convulsion which have been severer with advance in age, had periodic hyperammonemia, hyperlysinemia and homocitrullinuria. Blood cell arginase activity of the patient on normal diet was markedly reduced after an oral load of L-lysine. The oral loading tests of L-lysine revealed hyperammonemia, hyperlysinemia, hyperargininemia, hypercitrullinemia and homocitrullinuria. Etiology of metabolic error of our patient was discussed in reference to lysine-urea cycle.

Adolescent↗