No abstract

The objective of this study was to evaluate the influence of dietary nucleotide supplementation in preterm infants during the first month of life on the intestinal permeability to lactulose, mannitol and to β-lactoglobulin and on the development of circulating antibodies to β-lactoglobulin and α-casein. Twenty-seven preterm infants were enrolled in the study; 11 of them were fed a standard low-birth weight milk formula and 16 infants were fed the same formula supplemented with nucleotides at similar levels to those found in human milk. Blood and urine samples were obtained at 1 7 and 30 days of age. Serum β-lactoglobulin, serum IgG antibody to α-casein and serum IgG antibody to β-lactoglobulin were measured by ELISA. The lactulose/mannitol urinary excretion rate was measured by gas liquid chromatography. Neither the intestinal permeability to saccharides nor the intestinal absorption of β-lactoglobulin were affected by the nucleotide supplementation. However, serum concentrations of IgG antibody to β-lactoglobulin were higher in preterm neonates fed the supplemented formula than in those fed the standard formula. According to these results, dietary nucleotides might influence the maturation of the humoral immune response in preterm newborn infants.

Meconium drug analysis is a new and sensitive test for detecting the intrauterine exposure of infants to drugs of abuse. To explore other potential, diagnostic use of the test, we studied, in timed pregnant rats, the relationship between timing, dosage, and duration of morphine administration to the dam and the concentration of morphine, analyzed by radioimmunoassay, in their pups’ meconium. The term ‘meconium’ refers to both the intestine and its contents. Due to the minute size of the pups’ intestines, the intestinal contents were not separated from the intestines. The mean morphine concentration in meconium was found to be significantly (p < 0.05) higher in the groups treated with a higher morphine dose (10 vs. 5 mg/ kg/day), longer duration of treatment (7–20 vs. 18–20 days), or treated during the last week of gestation (14–20 vs. 1–6 or 7–13 days). We conclude that the concentration of a drug in the meconium is related to amount, timing, or duration of the drug exposure of the fetus, in utero. The quantitative analysis of drugs in the meconium, therefore, provides added information which enhances the diagnostic use of the test.

The pharmacokinetics of recombinant human erythropoietin was studied in 12 very low birth weight preterm infants < 32 weeks of gestation after subcutaneous administration of 300 IU/kg at a postconceptional age of 34 (32-37) weeks and a weight of 1,505 (1330–1,740)g (median and range). The administration of recombinant human erythropoietin produced a rapid increase n serum erythropoietin levels with a peak level of 362.8 mlU/ml at 8.9 h. The area under the curve was 8,177.5 (4,597.1–15,453.0) mlU/ml/h, the absorption half-life was 5.5 (1.6–6.6) h, the elimination half-life was 7.9 (5.6–19.4) h, and the residence time was 19.6 (5.1–32.6) h (all values reflect median and range). There was no significant correlation between absorption and elimination half-life of erythropoietin and birth weight, gestational age, sex, and age and weight of the infants at the time of administration of erythropoietin. Based on absorption and elimination kinetics, the dosing interval for subcutaneous administration must not be < 48h.