Nathan Rudolph

Developmental Patterns of Antioxidant Defense Mechanisms in Human Erythrocytes

ABSTRACT: To obtain a profile of erythrocyte antioxidant defense potential during late fetal development, we studied selected antioxidant parameters in blood samples from 65 neonates with birth wt between 520 and 4210 g and from 12 healthy adults. Erythrocyte superoxide dismutase activity did not change significantly with maturation and no significant differences were observed among preterm infants grouped in increasing birth wt categories, term neonates, and adults. Erythrocyte catalase and glutathione peroxidase, as well as plasma vitamin E levels, showed highly significant positive correlations (p<0.001) with increasing fetal wt and gestational age; by term, CAT activity reached a level similar to the adult control group, but glutathione peroxidase activity, as well as plasma vitamin E levels, were markedly lower in all the preterm and in the term groups than in adults (p< 0.01). Erythrocyte glutathione S-transferase activity showed a negative correlation with increasing gestational age (p<0.01) and the adult values were considerably lower than any of the neonatal levels p< 0.001). The role of glutathione S-transferase in erythrocyte metabolism remains obscure. Maturational changes in the activity of the red cell enzymes that were studied and in the plasma vitamin E level were apparent from about 31-36 wk of gestation, suggesting that the stimulation for these changes may have commenced from about 28-31 wk.

Solitary Hepatic Abscess in a Newborn Infant: A Sequel of Umbilical Vein Catheterization and Infusion of Hypertonic Glucose Solutions

x 1.5 cm in size (Fig. 1). A lateral view of an intravenous pyelogram showed this bubble midway from front to back. A diagnosis of hepatic abscess probably due to Klebsiella was made. Treatment with kanamycin was continued for 21 days. Serial radiography showed progressive decrease in size and eventual disappearance of the gas shadow. The infant was discharged at five weeks of age. When seen several weeks later he was in good health and thriving.

307 ERYTHROCYTE (RBC) GLUTATHIONE S-TRANSFERASE: DEVELOP MENTAL PATTERNS IN PRETERM INFANTS

The glutathione S-transferases (GST) are a group of enzymes present in a number of tissues, including liver and RBCs. They initiate detoxification of endogenous and exogenous substances by conjugation with glutathione, and might act as storage proteins by binding nonsubstrate compounds such as heme and bilirubin. They also exhibit non-selenium-dependent glutathione peroxidase (GSH-Px) activity. The low activity of Se-dependent GSH-Px in neonatal RBCs compared with those from adults, and comparatively high activity of RBC GST in fullterm (FT) neonates, prompted a study of developmental patterns of RBC GST in preterm (P) infants.RBC GST was assayed in 23 P infants (birth wt 700–2100gm) and 12 FT infants soon after birth.Results:P had significantly higher activity than FT (*p<.01). Within the P group, a highly significant negative correlation was found between birth wt and enzyme activity (r=−0.61; p<.01). We speculate that these developmental patterns might reflect changes in heme &/or bilirubin ligand functions associated with heme turnover rates. They might also indicate a physiological inverse relationship between Se-dependent and Se-independent GSH-Px activity during development, and might require a re-evaluation of the interaction of fetal anti-oxidant protective mechanisms.

Difference between Spun Hct and Automated Hct in Infants of Diabetic Mothers (IDM), Macrosomic Infants (LGA) and Normal-Sized Infants (C)

Difference between Spun Hct and Automated Hct in Infants of Diabetic Mothers (IDM), Macrosomic Infants (LGA) and Normal-Sized Infants (C)

Comparison of Cord Blood Viscosity and C-Peptide Levels in Infants of Diabetic Mothers (IDM), Macrosomic Infants (LGA) and Normal-Sized Neonates (NC)

Comparison of Cord Blood Viscosity and C-Peptide Levels in Infants of Diabetic Mothers (IDM), Macrosomic Infants (LGA) and Normal-Sized Neonates (NC)

INFANTS OF DIABETIC MOTHERS (IDM), AS WELL AS LARGE FOR GESTATIONAL AGE INFANTS (LGA) REQUIRE DIFFERENT GUIDELINES FOR PARTIAL EXCHANGE TRANSFUSION(P.Ex. T.) |[dagger]| 1175

Variability in whole blood viscosity is dependent primarily on hematocrit(hct) levels, but red cell factors such as deformability and aggregability, and variations in plasma proteins also play a role. Previous studies had suggested that at a laboratory-standardized hct (50%), symptomatic IDM may have higher viscosity levels than healthy controls. We did a retrospective review of results from neonatal blood samples submitted to our laboratory during the past 5 years for viscosity determinations because of polycythemia and/or suspicion of hyperviscosity.119 neonatal records were available for review. The submitted blood samples were categorized into specific hct groups from 58% to 68%. Each hct group was divided into 2 subgroups: A) Infants who were known to be IDM, plus LGA infants not specifically documented as IDM. B) The remaining neonates who served as controls. Mean viscosity values of group A and of group B at each hct and at specific shear rates were compared by 2-way ANOVA. At each shear rate (90 and 11.25 sec-1) group A (IDM + LGA) was significantly greater than group B (control) (p<0.001). Mean viscosity values (centipoise) for the specified hct. groups are shown below at a shear rate of 90 sec-1: Table

548 RESPONSE OF SERUM TOTAL CHOLESTEROL AND HIGH DENSITY LIPOPROTEIN (HDL) LEVELS IK PREMATURE INFANTS TO VARIATIONS IN DIETARY LEVELS OF POLYUNSATURATED FATTY ACIDS (PUFA)

Premature infants between 1000 and 1600g were assigned at 3 days of age to one of 4 groups, and fed a standard formula in which only the proportion of PUFA was varied by changes in the fat blend, and in which the vitamin E:PUFA ratio was kept constant. Sequential blood sampling showed a progressive rise in serum HDL levels in virtually all infants by 20 days of age (p<.01). Total cholesterol levels rose significantly (p<.05) by 20 days only in the group on the lowest concentration (16%) of PUFA.The results demonstrate the ability of very-low-birth-weight infants to exhibit rapid metabolic adjustments in response to variations in dietary PUFA levels, though the long-term significance is conjectural at this time.

465 HEMATOLOGICAL AND BIOCHEMICAL CHANGES IN PREMATURE INFANTS ON 3 COMMERCIAL INFANT FORMULAS

Thirty healthy premature infants with birth weights between 1000g and 1600g were randomly assigned at 1 wk of age to 3 groups to determine the effect of 3 commercial infant formulas (Similac 20, Similac 20 with Iron, Iscmil - each containing 15 I.U. vit. E/liter) on various hematological, biochemical and growth parameters. During their hospital stay weekly determinations were made of hemoglobin (Hb); hematocrit (Hct); reticulocyte count; hydrogen peroxide hemolysis; red cell glutathione peroxidase (GSH-Px) and selenium (Se); plasma GSH-Px and Se; and serum Ca, P, alkaline phosphatase, protein, cholesterol and vit. E levels.Mean weekly rates of declines in Hb and in Hct, respectively, did not differ significantly in the 3 groups of infants. Among the infants with the highest rates of declines in Hct and Hb were some with persistently low serum vit. E levels; these were noted in all groups. Red cell and plasma GSH-Px and Se levels did not correlate with the rate of decline in Hb or Hct levels, nor was there a direct and constant correlation between hydrogen peroxide hemolysis and the rate of Hb decline. A decline in serum phosphorus levels was noted in all 3 groups, but was significantly greater (p<.01) in the Isomil group. Under the conditions of our study, iron at the concentration used in Similac with Iron (12 mg/L) did not appear to accelerate hemolysis. Individual variability in the hematological responses was noted irrespective of the formula used.

ABDOMINAL DISTENSION IN INFANTS ON PHOTOTHERAPY

We noted that infants undergoing phototherapy (Phx) often develop abdominal distension, and thus undertook a study to evaluate possible mechanisms for this distension. 20 infants on continuous Phx with standard methods of eye occlusion were compared with two control groups - jaundiced infants not on Phx, and healthy non-jaundiced infants. The abdominal circumference was measured prior to feeding. Treated infants exhibited an increase in abdominal circumference ranging from 1-4 cm (mean 2.5) compared with 0-1 cm (mean 0.5) in each of the two control groups; distension was noted within 8-12 hours, reaching a maximum by ca 24 hours.In 4 infants intermittent Phx with intermittent eye occlusion (16 hrs. on, 8 hrs. off) resulted in intermittent abdominal distension during light periods, with a mean increase in circumference of 1.9 cm. In 15 additional infants in whom eye occlusion (and Phx) was discontinued during all feeding periods and re-applied after feeding, abdominal distension still developed (1-3 cm, mean 2.3).Preliminary studies were performed in which infants on Phx did not have their eyes occluded but had their faces shielded by a black screen; abdominal distension did not develop. Subsequent eye occlusion did produce abdominal distension, suggesting that the distension was the result of eye occlusion rather than the direct result of Phx. These findings may be significant in evaluating other sequelae of Phx, e.g. behavioral changes.

Creatine phosphokinase (CPK) activity in serum of newborn infants as an indicator of fetal trauma during birth

Serial studies have demonstrated a frequent rise in the activity of the enzyme creatine kinase in the serum of newborn infants following delivery. The rise in activity is independent of the maternal enzyme level. Considerable elevations in serum creatine kinase activity, noted especially at 24 hours of age, have been found in a number of infants delivered as breech presentations, following secondary uterine inertia with oxytocin stimulation, and following emergency Cesarean section after a trial of labor. Muscle damage sustained by the infant during the birth process is suggested as a likely cause for the increase in neonatal serum enzyme activity.