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Biomedical subjects

C J van den Berg

Publications and source records attributed to C J van den Berg.

16 recordsLinked to original sources
PubMed1995

Clinical symptoms of adult metachromatic leukodystrophy and arylsulfatase A pseudodeficiency.

OBJECTIVE: To determine the clinical symptoms in adult metachromatic leukodystrophy and in adult pseudodeficiency for arylsulfatase A. DESIGN: Case series. SETTING: University hospital. PATIENTS: Twenty-five adult patients with very low arylsulfatase A activity. RESULTS: In 13 patients, a diagnosis of adult metachromatic leukodystrophy was made. The main symptoms were dementia, behavioral abnormalities, ataxia, and polyneuropathy. In 12 patients, a diagnosis of arylsulfatase A pseudodeficiency was made. No characteristic clinical syndrome could be detected in these patients. CONCLUSIONS: Adult metachromatic leukodystrophy is a progressive metabolic disease with symptoms of demyelination of the central and peripheral nervous systems. Diagnosis must be confirmed by determination of arylsulfatase A activity and accumulation of sulfatides. Pseudodeficiency for arylsulfatase A can be confirmed or excluded by means of DNA analysis.

Adolescent↗
PubMed1988

In vivo identification and quantitative evaluation of carrier-mediated transport of lactate at the cellular level in the striatum of conscious, freely moving rats.

Intracerebral dialysis has allowed the continuous, on-line measurement of lactate in the extracellular fluid (ECF) of conscious, freely moving rats. The rapid time response of the technique allows the direct determination of the time course of changes in lactate in ECF following externally imposed stimuli. The time course of lactate appearance in ECF was found to be considerably slower than that observed in tissue following electroconvulsive shock or during ischemia following cardiac arrest. The ECF data could be fit to an integrated Michaelis-Menten model that assumed reversible transport of lactate across the cell membrane. This transport was found to act only when energy supplies could maintain membrane integrity and function, since ECF levels of lactate failed to follow tissue levels after cardiac arrest when energy resources are depleted. The calculated rate of cellular lactate transport was two orders of magnitude faster than transport of lactate across the blood-brain barrier in the adult rat, and passive diffusion of lactate was not found to contribute significantly across either cell or blood-brain barriers. Probenecid, an inhibitor of acid transport, was able to block both the efflux of lactate from cell to ECF and the consequent reuptake of lactate by cells in the striatum of the rat following electroconvulsive shock or ischemia.

Animals↗
PubMed1980

Two patients with an unusual form of type II fucosidosis.

Two brothers with an unusual form of fucosidosis are presented, providing further evidence for the clinical heterogeneity of the disease. The patients have several characteristics of type II, but from the point of view of progression rate and survival, they resemble more type III. However, the characteristic skin lesions of type III are not seen. In contrast to all other subtypes, a dry, thin skin is observed. The authors tend to classify these patients as a "slow motion" type II variant. Both in leukocyte lysates and plasma, severe alpha-L-fucosidase deficiency was established. In the parents, intermediate alpha-L-fucosidase activities were observed in leukocytes, but normal values in plasma, indicating that plasma is not suitable for carrier detection in this family. It is felt that no conclusions regarding clinical subtypes of fucosidosis can be drawn without careful characterization of the mutant enzyme in the primarily affected tissues.

Adult↗
PubMed1971

A simulation study of brain compartments. Metabolism of glutamate and related substances in mouse brain.

A computer model of the metabolism of glutamate, glutamine, gamma-aminobutyrate, and the tricarboxylic acid cycle in mouse brain has been constructed in terms of 39 reactions among 19 substances or groups of substances (permitting manipulation of 30 independent variables). The model is divided into two compartments, in conformity with previous models based on indirect evidence, and it is found that this compartmentation is indeed the same as that indicated directly with specifically (14)C-labelled acetate and glucose. The movement of materials between the large and small compartments has been studied; glutamine appears to flow from the small to the large compartment, gamma-aminobutyrate in the reverse direction.

Acetates↗