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Biomedical subjects

J Troost

Publications and source records attributed to J Troost.

58 records · Page 4Linked to original sources

Human leucocyte alpha-L-fucosidase.

1. Human alpha-L-fucosidase (EC 3.2.1.51) was studied from leucocytes, urine and serum. 2. The leucocyte and urine enzymes are similar in many properties (KM, pH optimum, electrophoretic pattern, heat stability). 3. The serum alpha-L-fucosidase differs from the leucocyte and 4rine enzyme wit,respect to: electrophoretic pattern, pH optimum and heat stapility. 4. The molecular weight of leucocyte alpha-L-fucosidase was determined to be 80 000 +/- 5000. 5. Cu2+, Hg2+ and PCMB are strong inhibitors of leucocyte alpha-L-fucosidase. This inhibition could be completely reversed by beta-mercaptoethanol, indicating that thiol groups are essential for catalytic activity.

Anions↗

Characterization of alpha-L-fucosidase from two different families with fucosidosis.

1. Two different families with a different type of fucosidase deficiency are described. 2. In the first family the activity of alpha-L-fucosidase in leucocytes of two patients with fucosidosis type I was about 4 to 8% of the normal value. The activity of alpha-L-fucosidase in the leucocytes of the father and the mother are in the heterozygote range, while a sister of the propositus showed normal values. 3. The activity of alpha-L-fucosidase of the propositus from urine, serum and liver were also severely decreased. The activity of alpha-L-fucosidase in the urine of the parents and the healthy sister of thr propositus were about 5% of the mean normal value. However in the serum these values were above 50%. 4. The KM value for alpha-L-fucosidase from leucocytes of the patient was increased about 10 times and in serum this value was even higher. The KM values from the enzyme of the parents were in the normal range. 5. The abnormal enzyme from the propositus is unique in its thermal behaviour since after heating its activity increased. 6. In the second fanily the activity of alpha-L-fucosidase in the leucocytes of the patient is about 30% of the mean normal value, while the arylsulphatase A activity is also decreased (25% of the mean normal value). 7. The activity of alpha-L-fucosidase from the leucocytes of the father and the healthy brother are about 50% of the mean normal level, while the enzyme of the mother showed a normal activity. 8. The alpha-L-fucosidase activity in the urine and the liver of the propositus is also decreased. The serum enzyme activity however was in the normal range. 9. The KM value of alpha-L-fucosidase and heat stability of the enzyme of the patient were normal. In the leectrophoretic pattern of the whole family one bond was missing.

Acetylglucosaminidase↗

Hypertensive encephalopathy in childhood. Diagnostic problems.

Oppenheimer and Fischberg's vasoconstriction-hypothesis on the pathogenesis of hypertensive encephalopathy was subsequently supported by animal experiments. Later on the role of decompensation of the autoregulatory mechanism of the cerebral blood flow was revealed. The transient symptomatology comprises headache, seizures, focal cerebral symptoms (hemiplegia etc.), visual disturbances, mental disorders, papiledema etc. The age-dependency of the influence of edema is probably expressed by the predominance of seizures in childhood and the long duration of the symptoms in our third and fourth patient. The differentiation between hypertensive encephalopathy and a local complication of hypertension (hemorrhage) can be difficult, not at least because the first disturbance may be followed by the second (patient 3). Hypertension is not always present as initial symptom (patient 1 and 2). Hence a series of blood pressure readings is required in acute cerebral incidents in childhood. Steroid-treatment may lead, especially in patients suffering from a hypocomplementemic form of membranoproliferative glomerulonephritis, to a sudden rise of the blood pressure and subsequently to hypertensive encephalopathy (patients 2 and 3). Hypertensive encephalopathy is a neuropediatric emergency. The urgent treatment with dioxaside, fursemide and sodium nitroprusside is shortly reviewed.

Adolescent↗