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L R Bernard

Publications and source records attributed to L R Bernard.

3 recordsLinked to original sources

A fatal variant of human ornithine carbamoyltransferase is stimulated by Mg2+.

Biochemical studies of a female who died at 2 years of age from a possible genetic variant of ornithine carbamoyltransferase (OCTase) deficiency are reported. The patient had severe psychomotor retardation with plasma ammonia levels throughout life reaching as high as 500 mumole/liter. The average OCTase level in the patient's liver was 2% of that in normal livers. Preincubation with 0.05 M MgCl2 resulted in a 570% increase in OCTase activity (13% of control). Citrate synthase and carbamoyl-phosphate synthase I were present at essentially normal levels. Unusual Mg2+ requirements have not been recognized in previous reports of OCTase deficiency, suggesting a genetic variant in this patient.

Amino Acid Metabolism, Inborn Errors↗

Neuropathology of ornithine carbamyl transferase deficiency.

Neuropathologic findings in two cases of ornithine carbamyl transferase (OCT) deficiency are presented. In one, a boy 3 days old, the only abnormality related to the enzyme defect was metabolic gliosis which was unusual in distribution being present mainly in the brain stem. In the other case, a girl who died at the age of 2 3/12 years, the brain showed metabolic gliosis in typical location, widespread ulegyria, and moderate atrophy of the internal granular layer in the cerebellum accompanied by development of expansions of Purkinje cell dendrites. Case 2 demonstrates how rapidly changes previously demonstrated in the cerebral cortex after a few months of illness can proceed to massive hemispheric destruction. By now ulegyria has been observed in several disorders of the urea cycle.

Brain↗