Enzymes of lysosomal origin in the serum of infants of diabetic mothers behavior in the first days after birth

Lysosomal enzymes in preterm infants with bronchopulmonary dysplasia: a potential diagnostic marker

Some lysosomal glycohydrolases (N-acetyl-beta-D-glucosaminidase and their major isoenzymes, beta-D-glucuronidase, alpha-D-galactosidase, beta-D-galactosidase and alpha-D-glucosidase) were investigated in the plasma of 36 preterm infants with respiratory distress, 11 of whom developed bronchopulmonary dysplasia (BPD), in order to evaluate the role of the lysosomal apparatus in the disease. Enzyme activity was assayed fluorimetrically; the major N-acetyl-beta-D-glucosaminidase (NAG) isoenzymes were separated using a routine chromatofocusing procedure; the diagnostic efficiency was evaluated by Bayes theorem. The mean levels of almost all glycohydrolases considered were significantly higher in BPD than in non-BPD infants. Among NAG major isoenzymes, an increase was found only in form A. No variation was evident in the plasma levels of glycohydrolases during dexamethasone therapy. Data from a retrospective analysis performed in all preterms considered, show that alpha-D-galactosidase and beta-D-galactosidase differentiate a posteriori BPD and non-BPD subjects. These enzymes, after a priori verification of their diagnostic potential in preterm infants at risk of BPD development, could acquire an important predictive value.

Enzymes of lysosomal origin in plasma of twin neonates

The levels of some enzymes of lysosomal origin were assayed during days 2 and 5 of life in plasma from 11 sets of twin neonates and from 25 neonates from single pregnancies (13 of weight appropriate for gestational age and 12 small for their gestational age) as controls. The plasma enzyme levels were also determined in the correspondent twin and control mothers 2 days after delivery. N-Acetyl-beta-D-glucosaminidase isoenzymes were assayed after chromatofocusing separation. All the plasma enzyme levels were higher in the group of twin neonates and of their mothers than in the respective control groups with differences highly statistically significant for two enzymes, beta-D-galactosidase and alpha-D-glucosidase. In neonate plasma lysosomal enzymes are increased at the fifth day of life with respect to the second day. Full term control neonates showed the same enzyme trend. For the N-acetyl-beta-D-glucosaminidase the more significant differences concerned the isoenzyme I2-P (pregnancy). The pattern of the lysosomal enzymes in the twins resembled that of neonates of diabetic mothers who had had no insulin therapy. Since lysosomal enzymes are considered to be particularly sensitive indicators of carbohydrate metabolism abnormalities, we conclude that twin pregnancies are more at risk for these abnormalities than single ones.