Serum calcium regulating hormones in the perinatal period.

To clarify perinatal vitamin D metabolism, we measured 25-hydroxyvitamin D (25OHD), 24,25-dihydroxyvitamin D [24,25(OH)2D], 1,25-dihydroxyvitamin D [1,25(OH)2D], calcium (Ca), phosphorus (P), parathyroid hormone (PTH), and human calcitonin (CT) in paired maternal, cord, and infant serum. Cord serum 25OHD was significantly lower than the maternal level, and cord serum 24,25(OH)2D was also significantly below the maternal concentrations. Maternal, cord, and infant serum 1,25(OH)2D, on the other hand, was significantly higher than the normal adult level. The serum PTH was low, but the CT concentration was high in the cord. Cord serum Ca and P levels were significantly higher than maternal. The reason for the elevated circulating 1,25(OH)2D level in the perinatal period is uncertain, and we speculate that the possible factors are gonadal steroids, placental lactogen, prolactin, and CT. In addition, serum 24,25(OH)2D and 1,25(OH)2D concentrations are under some control by the fetus.

A specific competitive protein binding assay for serum 24,25-dihydroxyvitamin D in normal children and patients with nephrotic syndrome.

A specific competitive protein binding assay for 24,25-dihydroxyvitamin D by Sephadex LH-20 column chromatography, followed by high pressure liquid chromatography with normal rat kidney cytosol as the binding protein, was developed. The mean concentrations of serum 24,25-dihydroxyvitamin D of the cord, in newborn infants and in infants under 12 months of age were 0.90 +/- 0.40 (S.D.) ng/ml, 0.52 +/- 0.21 (S.D.) ng/ml and 1.20 +/- 0.38 (S.D.) ng/ml, respectively. These concentrations were significantly lower than those in children aged 1-15 years (1.96 +/- 0.83 (S.D.) ng/ml). The serum levels in the acute stage of the nephrotic syndrome were significantly reduced, and they increased in remission. These results show that patients wioth nephrotic syndrome have low levels of serum 24,25-dihydroxyvitamin D. This is probably due to its loss in the urine.

Plasma 1,25-dihydroxyvitamin D concentrations in cords, newborns, infants, and children.

Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2-D] was measured in cord serum, newborns, infants, and children. The mean for the values obtained from the six cords was significantly higher than the mean for the older children (6-15 years). The mean for the six newborns (0-1 week) was significantly higher than that for the older children. The mean for the nine infants (1 week-6 months) and the 14 younger children (6 months-6 years) was significantly higher than that for older children. The present study suggests that the perinatal period is associated with a marked increase in 1,25-(OH)2-D.

Treatment of hypophosphataemic vitamin D-resistant rickets with massive doses of 1 alpha-hydroxy-vitamin D3 during childhood.

Plasma levels of 1,25 dihydroxy-vitamin D (1,25-(OH)2-D) were low in 3 children with hypophosphataemic vitamin D-resistant rickets (HVDRR) during childhood, but increased after very large doses (0.5 to 2 micrograms/kg per day) of 1 alpha-hydroxy-vitamin D (1 alpha-OH-D3). This treatment has two advantages. Firstly, hypercalcaemia is easily controlled by reducing the dose of 1 alpha-OH-D3 because of its short half-life. Secondly, the administration of 1 alpha-OH-D3 to patients with HVDRR can enhance the tubular reabsorption of phosphate, and this seems desirable in treating HVDRR.

A case of neuraminidase deficiency associated with a partial beta-galactosidase defect. Clinical, biochemical and radiological studies.

Neuraminidase deficiency towards fetuin, 2 leads to 3 sialyllactose and 2 leads to 6 sialyllactose was found in cultured skin fibroblasts from a 10-year-old Japanese girl who exhibits craniofacial dysmorphism, a short neck, vertebral and pelvic deformities and macular cherry-red spots. Neuraminidase deficiency in this case seems the primary enzyme defect because the enzyme activity of her parents was intermediate. In addition, beta-galactosidase in leukocytes and cultured skin fibroblasts from the patient was found to be severely deficient, but could be detected in serum and urine. In the parents, beta-galactosidase activity was normal. There were moderately increased levels of urinary sialic acid-rich oligosaccharides and glycopeptides in the patient. The clinical and biochemical observations suggest that this case is very close to mucolipidosis I.

The plasma levels of 25-hydroxyvitamin D in patients with various liver diseases and the response of 25-hydroxyvitamin D to vitamin D treatment.

The mean plasma levels of 25-hydroxyvitamin D (25-OH-D) were measured before and after the administration of 2000 units of daily oral vitamin D2 for a period of 2 weeks in 9 normal infants and children, 7 infants with neonatal hepatitis and persistent neonatal hepatitis, and 4 infants with congenital biliary atresia. The mean plasma level of 25-OH-D increased significantly from 19.5 +/- 3.7 (S.E.) ng/ml to 34.0 +/- 6.8 (S.E.) ng/ml after administration of vitamin D2 in controls (p less than 0.05). The mean plasma level of 25-OH-D also increased from 8.0 +/- 2.1 (S.E.) ng/ml to 22.1 +/- 2.6 (S.E.) ng/ml after vitamin D treatment in hepatitis group (p less than 0.05). In patients with congenital biliary atresia, vitamin D treatment did not affect eh plasma levels of 25-OH-D.