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Biomedical subjects

Y S Shin

Publications and source records attributed to Y S Shin.

At least 127 records · Page 7Linked to original sources
PubMed1988

Report on a new patient with combined deficiencies of sulphite oxidase and xanthine dehydrogenase due to molybdenum cofactor deficiency.

A newborn infant exhibiting seizures and spastic tetraparesis at the age of 1 week was shown to excrete excessive quantities of sulphite, taurine, S-sulphocysteine and thiosulphate, characteristic of sulphite oxidase deficiency. In addition, increased renal excretion of xanthine and hypoxanthine combined with a low serum and urinary uric acid was consistent with xanthine dehydrogenase deficiency. Both deficiencies could be established at the enzyme level. The primary defect giving rise to the combined abnormalities is the absence of a molybdenum cofactor, a molybdenum-containing pterin being an essential component of both enzymes. The patient developed a severe neurological syndrome, brain atrophy and lens dislocation and died at the age of 22 months. Attempts at treatment, such as oral administration of ammonium molybdate, sodium sulphate, D-penicillamine, 2-mercaptoethane sulphonic acid, pyridoxine and thiamine did not influence the clinical course.

Abnormalities, Multiple↗
PubMed1988

[Double heterozygosity (transferase-/epimerase-defect) and galactosemia cataract].

The mother of a boy who suffered from classical galactosaemia (galactose-1-phosphate uridyl transferase deficiency) has unilateral cataracta. In addition the boy had a decreased activity of the UDP-galactose-4-epimerase. The latter defect could also be demonstrated in the erythrocytes from the mother and the grandmother. In contrast to the finding of cataracta in the mother the grandmother with the same type of double heterozygosity was ophthalmologically normal. The implication of partial maternal disorders of galactose metabolism will be discussed in view of their possible role for the origin of cataracta.

Carbohydrate Epimerases↗
PubMed1987

Agarose gel isoelectrofocusing of UDP-galactose pyrophosphorylase and galactose-1-phosphate uridyltransferase. Developmental aspect of UDP-galactose pyrophosphorylase.

The uridine diphosphogalactose pyrophosphorylase activity has been determined in human adult and fetal tissues as well as blood of various ages by measurement of UDP-galactose production from gal-1-p and UTP. The highest activity was found from adult liver in which the specific activity was about 5% of the gal-1-p uridyltransferase activity. In general adult tissues had a somewhat higher activity than the corresponding fetal tissues except erythrocytes in which fetuses had a 5-10 times higher activity than adults. From normal blood the pyrophosphorylase activity in erythrocytes decreased with age, but in the case of galactosemia the decrease with age was not distinct. According to agarose gel isoelectrofocusing studies, at least two isozyme forms for UDP-galactose pyrophosphorylase exist with the activity bands between pH 6.0-6.15. The patterns of AGIF bands of pyrophosphorylase varied according to the age of the samples, suggesting the development of the isozyme forms of pyrophosphorylase to be age-dependent. Uridyltransferase, on the other hand, resolved into multiple bands between pH 5.1-5.6 on agarose gels and the patterns varied according to the variants but not to the age. Significance of the decrease in the pyrophosphorylase activity in erythrocytes with age as well as of the difference in AGIF bands between normal and the galactosemic were discussed with regard to the pathology of classical galactosemia.

Adolescent↗
PubMed1987

Increased concentrations of HbAlab in hereditary fructose intolerance and galactosemia.

In patients with diabetes mellitus nonenzymatic glycosylation of hemo-globin is a result of increased blood glucose concentrations. In analogy glycosylated hemo-globin fractions were determined in 23 patients with hereditary fructose intolerance (HFI) and 8 patients with galactosemia (G) by means of hemoglobin chromatography on a column packed with Bio-Rex 70 resin. The concentrations were compared to those of 14 control patients and 43 patients with type 1 diabetes mellitus. Compared to controls, in HFI- and G-patients HbAlab was significantly increased. In contrast diabetic patients presented with a marked and significant increase of the HbAlc fraction. When purified hemoglobin was incubated with different monosaccharides respectively monosaccharide phosphates, an increase of HbAlab resulted mainly after galactose and fructose-1-phosphate. The determination of HbAlab in patients with HFI and G is considered a possible means of metabolic control.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1986

Progressive cerebellar and extrapyramidal motor disturbances in galactosaemic twins.

Progressive cerebellar and extrapyramidal motor disturbances are described in two 16-year-old female twins with classical galctosaemia. The neurological disturbances, characterized by hyper- and dysmetric movements and bilateral intention tremor with choreatic, atactic and even ballistic motor storms, appeared at 12 years of age. Computerized tomography demonstrates cerebral atrophy in cerebellar, brain stem and basal ganglia structures. The central conduction times, determined by somatosensible evoked potentials, are grossly prolonged; the peripheral nerve conduction velocities are normal. The neurological sequelae described are considered a distinct entity in the course of galactosaemia.

Adolescent↗
PubMed1986

First trimester diagnosis of Pompe's disease (glycogenosis type II) with normal outcome: assay of acid alpha-glucosidase in chorionic villous biopsy using antibodies.

Prenatal diagnosis of glycogenosis type II was performed by direct assay of acid alpha-glucosidase (EC 3.2.1.20) in chorionic villous biopsy obtained by transcervical cannula aspiration from a pregnancy at risk in the 10th week of gestation. The exact value of the enzyme activity estimated by the use of antibody preparations for purified human liver acid alpha-glucosidase was in the heterozygous range, and so the homozygous enzyme deficiency could be excluded. The subsequent analysis of cells cultured from amniocentesis sampling in the 18th week of gestation resulted in a similar outcome. The study with antibodies showed that in 23 control chorionic villi obtained during gestational ages between 7-13 weeks, 1-15% of the total alpha-glucosidase activity at pH 4.0 were due to renal or neutral enzyme. This indicates that it may be important to employ antibodies for prenatal diagnosis using chorionic villous sampling. A healthy and unaffected boy was born. The biochemical values obtained from an umbilical blood specimen were in accordance with the results of the prenatal diagnosis.

Adult↗
PubMed1985

Diagnosis of Pompe's disease using leukocyte preparations. Kinetic and immunological studies of 1,4-alpha-glucosidase in human fetal and adult tissues and cultured cells.

Kinetic and immunological studies of 1,4-alpha-glucosidase show that the distribution of acid, renal and neutral alpha-glucosidase at pH 4.0 and 6.5 is as follows: in liver and cultured fibroblasts and amniotic fluid cells the activity at pH 4.0 is mainly due to the acid enzyme. Even at pH 6.5, the activity is largely due to the residual activity of the acid enzyme. In kidney and leukocytes, however, the activity by acid enzyme at pH 4.0 represents only 30-60% of the total activity and the remaining activity is from renal enzyme. At pH 6.5, the activity is almost exclusively of renal enzyme. Renal alpha-glucosidase has a higher affinity for maltose (Km, 0.8 mmol/l) than acid enzyme, however; for glycogen acid enzyme shows the highest affinity (20.7 g/l). There is no significant difference in the kinetic characteristics of alpha-glucosidase between fetal and adult tissues. In kidney, however, a relative increase in renal enzyme to acid enzyme with age is found, i.e. in fetal kidney the alpha-glucosidase activity at pH 4.0 is more than twice that at pH 6.5, whereas in adult kidney, the activity ratio at pH 4.0-6.5 is approximately 1. Antibodies for human liver acid alpha-glucosidase decrease the alpha-glucosidase activity in normal leukocytes by 22-75% at pH 4.0 (0.54-3.8 nmol/min per mg protein). The decrease is significantly lower in patients with Pompe's disease (0-0.11 nmol/min per mg protein) as well as in their parents and some siblings (0.15-0.70).

Adult↗