Prenatal diagnosis and family studies in a case of propionicacidaemia

In a family with a history of two neonatal deaths, propionicacidaemia was diagnosed retrospectively from stored plasma as the cause of the second death during the mother's next pregnancy. Amniocentesis was performed and a culture of amniotic cells was assayed for propionyl CoA carboxylase activity. The absence of any detectable propionyl CoA carboxylase activity allowed the prenatal diagnosis of propionicacidaemia to be made. Treatment with biotin and a modified aminoacid diet was started in the immediate postnatal period. Investigation of propionyl CoA carboxylase in leucocytes from the parents, siblings and other relations of the patient failed to demonstrate intermediate enzyme activities in even the parents, who were presumably heterozygotes for this condition.

Palmitic acid concentrations and lecithin/sphingomyelin ratios in amniotic fluid

Palmitic acid concentrations and L/S ratios have been estimated in amniotic fluid specimens with and without centrifugation and cold acetone precipitation. Although the number of cases was small, both of these measurements in uncentrifuged fluid seemed to reflect only indirectly on lung maturation in normal pregnancy while with centrifuged fluid the L/S value predicted RDS in one infant more reliably than palmitic acid concentration.

Quality of survival after artificial ventilation of the newborn

Fifty children now aged 4 to 8 years who required artificial ventilation for respiratory failure in the neonatal period were followed up; 44 (88%) had no serious mental or physical handicap. 35 of the ventilated infants were matched with paired controls who had also had respiratory distress but had not required artificial ventilation. Detailed studies of growth, respiratory and neurological function, and psychological testing revealed only minor differences between the two groups. It is concluded that the quality of survival after artificial ventilation of the newborn justifies the procedure.

Effect of moderate dosage of chlorpropamide in pregnancy on fetal outcome

The outcome of 19 pregnancies is reviewed in women receiving daily doses of at least 200 mg chlorpropamide for varying degrees of glucose intolerance. 4 required insulin in late pregnancy. In 13 mothers who had chlorpropamide during the first 13 weeks of pregnancy no fetal abnormality occurred. There were 2 intrauterine deaths, 1 neonatal death, 6 babies with birthweights greater than the 90th centile, and 2 with birthweights below the 10th centile. The total dosage taken during pregnancy varied from 5 to 105 g and the duration of administration varied from 3 to 39 weeks. Though the severity of diabetes loosely correlated with the daily chlorpropamide dosage, no constant relation existed between high daily dosage of chlorpropamide and obstetric or neonatal complications. It is concluded that it is more likely to be the poor control of the maternal diabetes in pregnancy than a pharmacological effect of the chlorpropamide on the fetal pancreas which is responsible for the poor results reported. 6 infants had intravenous glucose tolerance tests done within 3 hours of birth and the rate of glucose disposal and insulin response was found to be greater than in infants of untreated mothers with less severe diabetes.

Respiratory mechanics in infants of low birth weight and the effects of feeding

Pulmonary mechanics were measured at rest and after feeds in 54 neonates of low birth weight. Infants with appropriate weight for their gestational age showed an increase in compliance and a small, but not significant decrease in elastic and viscous work after feeds. These changes were not seen in ‘light-for-date’ infants. There was no evidence of any harmful effect of feeding on the respiratory mechanics of these infants.

DIPHOSPHONATES

1. The phosphonates are simple chemical compounds containing P-C-P bonds which are resistant to the action of naturally occurring phosphatases and pyrophosphatases. They inhibit the formation and dissolution of apatite crystals in vitro and prevent ectopic mineralisation and bone resorption in animals.

2. In man one diphosphonate (EHDP) has been shown to reduce the excessive turnover of bone in Paget's disease and also appears to slow the mineralisation of ectopic bone matrix in myositis ossificans progressiva.

3. The possible uses of the diphosphonates in bone disorders with excessive resorption and in ectopic mineralisation are being further investigated.

Insect Moulting Hormones: Dacrysterone, a New Phytoecdysone From Dacrydium intermedium

Dacrysterone, a new phytoecdysone, has been isolated from the bark of Dacrydium intermedium and shown to be 5β-hydroxymakisterone A (6). Makisterone A also occurs in this plant.