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Biomedical subjects

J Dancis

Publications and source records attributed to J Dancis.

At least 91 records · Page 5Linked to original sources

Lysine-ketoglutarate reductase in human tissues.

Lysine-ketoglutarate reductase (saccharopine dehydrogenase (NADP+, lysine-forming) EC 1.5.1.8) from human liver has been partially purified and characterized. A spectrophotometric assay is described. The Michaelis constants have been determined for lysine (1.5-10-3 M), alpha-ketoglutarate (1-10-3 M) and NADPH (8-10-5 M). The pH optimum is 7.8. The enzyme is product inhibited. The specificity of the enzyme, response to inhibitors, pH and thermal stability are reported. Lysine-ketoglutarate reductase is present in high concentration in liver and heart, to a lesser degree in kidney and skin and in trace amounts in several other tissues. Saccharopine dehydrogenase (saccharopine dehydrogenase (NAD+, L-glutamate-forming) EC 1.5.1.9) was demonstrable only in liver and kidney. Lysine-ketoglutarate reductase reacts effectively with delta-hydroxylysine.

Humans↗

The sural nerve in familial dysautonomia.

In familial dysautonomia there are malfunctions of motor, sensory and autonomic systems. The sural nerve has reduced transverse fascicular area, diminished numbers of myelinated axons (particularly those of small diameter) and very few non-myelinated axons. Catecholamine containing endings are not found in accompanying arteries. These changes are compatible with reduced neuronal populations described in sympathetic and sensory ganglia. The observed pathology accounts for many of the clinical features of the disease and suggests an abnormality in intrauterine development.

Adolescent↗

Serum dopamine-beta-hydroxylase in familial dysautonomia.

The mean value of serum dopamine-beta-hydroxylase (D beta H) in patients with familial dysautonomia, 1 to 5 years of age, does not differ significantly from control children of the same age (24.0 plus or minus 21.06 S.D. as compared to 34.0 plus or minus 33.12). Among patients 6 years of age and over, the mean value was slightly but significantly lower than in control subjects (62.7 plus or minus 49.61, as compared to control values of 86.1 plus or minus 54.31 p less than 0.025). However, the determination of serum D beta H does not contribute to the diagnosis of familial dysautonomia because well over half the children have levels within 1 S.D. of the mean levels of the control subjects. There is no correlation with clinical symptomatology. The disease process may tend to depress the level of serum D beta H but the effect is neither consistent nor decisive.

Adolescent↗

Variant maple syrup urine disease in mother and daughter.

Intermittent MSUD in a mother and her daughter is reported. Fibroblast cultures were studied for branched-chain keto acid decarboxylase and results show that the mother has approximately 12% while the daughter has 5% of the normal enzyme activity. Other key members in the family were also studied for enzyme activity. It appears that the child has inherited an abnormal gene from her homozygous mother and another abnormal gene from her heterozygous father.A classification based on the degree of residual enzyme activity and protein tolerance places the mother in grade III and the daughter in grade II category. Classical MSUD, where the enzyme activity is less than 2% of normal, belongs to grade I.

Adult↗