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T Vulsma

Publications and source records attributed to T Vulsma.

10 recordsLinked to original sources
PubMed1992

Use of amiodarone during pregnancy.

UNLABELLED: Five cases are studied in which amiodarone (AM) was given during pregnancy, in two of them also during the breast feeding period, to estimate the risks for adverse effects. We measured the concentrations of AM and its major metabolite desethylamiodarone (DEA) in maternal plasma, cord plasma, infant plasma, placental tissue and breast milk and the thyroid hormones were measured in maternal and neonatal serum. Also, the neonates were examined for AM-associated adverse effects over a period varying from 8 months up to 5 years. We observed a limited maternal-fetal transfer of AM and DEA, while the concentration of DEA in placental tissue is relatively high. Considerable amounts of AM and DEA were present in breast milk. One infant appeared to be hypothyroid, detected by the neonatal thyroid screening. He was treated with triiodothyronine for weeks, until it was clear that the thyroid dysfunction was resolved. The other infants had normal screening results. No effect of the AM medication was observed on growth, liver function or cornea and skin. IN CONCLUSION: although pregnancy and lactation are no absolute contraindications for use of AM, special precautions are necessary. It is unavoidable that in some cases the pregnant mother, and especially her infant, becomes hypothyroid. AM has to be administered in the lowest possible dose, and the maternal and neonatal thyroid function must be controlled as long as the exposure to AM lasts.

Amiodarone↗
PubMed1991

The role of serum thyroglobulin concentration and thyroid ultrasound imaging in the detection of iodide transport defects in infants.

When discovered by neonatal screening, a thyroid dyshormonogenesis is usually not recognized as a goitre. Especially a total iodide transport defect can easily be misclassified as thyroid agenesis, since radionuclide imaging cannot visualize the thyroid. We present the only iodide transport defect ever discovered in the Netherlands, the 35th reported in the literature, and the first one found exclusively as a result of neonatal screening. We demonstrate that iodide transport defects, in common with organification and deiodinase defects, can be distinguished from thyroid dysgenesis by demonstrating a normal or enlarged thyroid ultrasound image, and especially by measuring very high serum thyroglobulin levels (above 1000 pmol/l). In the presented case, an iodide-123 saliva-to-serum ratio near unity completed the etiologic classification. Measurement of serum thyroglobulin levels, in combination with thyroid ultrasound imaging, will improve the early identification of hereditary types of congenital hypothyroidism, and especially iodide transport defects, in patients found by neonatal thyroid screening.

Biological Transport↗
PubMed1989

Maternal-fetal transfer of thyroxine in congenital hypothyroidism due to a total organification defect or thyroid agenesis.

The fact that neonates who subsequently have severe hypothyroidism have no evidence of the condition at birth suggests the possibility of the placental transfer of thyroid hormones. Recent studies have demonstrated the existence of such transfer in hypothyroid rats. To determine whether there is a transfer of thyroxine (T4) from mother to fetus, we studied 25 neonates born with a complete inability to iodinate thyroid proteins and therefore to synthesize T4. This total organification defect is an autosomal recessive disorder with an incidence of approximately 1 in 60,000 neonates in the Netherlands. In the cord serum of affected neonates, T4 levels ranged from 35 to 70 nmol per liter. Since these patients were unable to produce any T4, the T4 must have originated in their mothers. The estimated biologic half-life of serum T4 was 3.6 days (95 percent confidence interval, 2.7 to 5.3). In 15 neonates with thyroid agenesis, the serum levels and the disappearance kinetics of T4 were the same as those in the neonates with a total organification defect, suggesting that in these infants, the T4 also had a maternal origin. We conclude that in infants with severe congenital hypothyroidism, substantial amounts of T4 are transferred from mother to fetus during late gestation.

Congenital Hypothyroidism↗
PubMed1989

Antibodies to 'second colloid antigen.' A study on the prevalence in sporadic forms of congenital hypothyroidism.

Antibodies against the so called 'second colloid antigen' (CA2 antibodies) occurred in 51% of the mothers of hypothyroid children detected by screening for neonatal congenital hypothyroidism in Quebec (N = 49) and in The Netherlands (N = 26). In The Netherlands where corresponding neonatal serum was available, 31% (8 of 26) of the infants with congenital hypothyroidism were positive for antibodies against the second colloid antigen. When during follow-up, 3 to 5 years after diagnosis, the mothers and their children were investigated, 46% (7 of 15) of the mothers were positive for antibodies against the second colloid antigen, whereas 29% (4 of 14) of the hypothyroid children were also positive. Various control groups did not show more than a 12% positivity. This presence of thyroid-reactive antibodies in a proportion of the hypothyroid children 3 to 5 years after diagnosis is not compatible with a mere transplacental passage; it indicates that the antibodies must be produced by the mothers and by the children themselves. We conclude that a thyroid autoimmune response occurs in a considerable part of infants with congenital hypothyroidism and their mothers and that this immune response seems to persist in both of them for years.

Adult↗
PubMed1986

[Congenital hypothyroidism. Current viewpoints and developments].

Since 1978 neonatal screening on congenital hypothyroidism (CHT) is performed in The Netherlands. A combined T4 and TSH determination is used. This creates the possibility to detect secondary and tertiary hypothyroidism. The number of false-positive cases is relatively high. This number decreases by adjusting the method of screening. Recent studies show a CHT incidence of 1:2100 newborns. In about 25% of these cases the CHT appears to be transient. Proceeding from the screening on CHT several investigations presented in this review are in progress.

Congenital Hypothyroidism↗
PubMed1978

Isolation procedure and some properties of myeloperoxidase from human leucocytes.

1. A rapid isolation procedure with a high yield for pure myeloperoxidase (donor:H2O2 oxidoreductase, EC 1.11.1.7) from normal human leucocytes is described. The enzyme was solubilized from leucocytes with the detergent, cetyltrimethylammonium bromide, and purified to apparent homogeneity. The yield of the enzyme was 17% with an absorbance ratio A430nm/A280nm = 0.85. 2. The purified enzyme showed three isoenzyme bands after polyacrylamide gel electrophoresis; ultracentrifuge studies indicated one homogeneous band with a molecular weight of 144 000. After reduction of myeloperoxidase, sodium dodecyl sulfate gel electrophoresis resolved an intense band (63 000 daltons) and a weak band (81 000 daltons). 3. The carbohydrate content of the enzyme was at least 2.5%. Mannose, glucose and N-acetylglucosamine were present. The amino acid composition is reported. 4. The EPR spectrum exhibited a high-spin heme signal with rhombic symmetry (gx = 6.92, gy = 5.07 and gz = 1.95). Upon acidification this signal was converted into a signal with more axial symmetry (g perpendicular = 5.89). At high pH (9.5) the EPR spectrum of the enzyme only shows low-spin ferric heme resonances. The circular dichroism spectra of ferric and ferrous myeloperoxidase in the visible and ultraviolet region show maxima and minima in ellipticity.

Amino Acids↗
PubMed1976

An EPR study of myeloperoxidase in human granulocytes.

1. EPR spectra of human granulocytes (4 - 10(8) cells per ml) show an intense high-spin ferric heme signal with rhombic symmetry (gx = 6.90 and gy = 5.07) for the heme group. These g-values are identical to those of partially purified myeloperoxidase and thus the signal is derived from ferric myeloperoxidase. In chicken granulocytes, which contain little or no myeloperoxidase, only an axial type of heme iron signal, weak in intensity, can be detected at g = 6.0. 2. Upon phagocytosis of latex particles by human granulocytes the high-spin heme signal with rhombic symmetry is slowly converted into a signal with axial symmetry (gx = gy = 6.0), showing that the EPR signals of myeloperoxidase in the intact cell can be used to study the involvement of the enzyme in metabolic changes during phagocytosis.

Animals↗