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Biomedical subjects

S Zlotkin

Publications and source records attributed to S Zlotkin.

21 records · Page 2Linked to original sources
PubMed1982

Differences in liver folate enzyme patterns in premature and full term infants.

The specific activities of four folate enzymes have been measured in livers from preterm infants (Group 1), full-term infants (Group 2), and from control subjects (Group 3). The four enzymes studied were methylene tetrahydrofolate reductase (EC 1.1.1.68), methionine synthetase (EC 2.1.1.13), methylenetetrahydrofolate dehydrogenase (EC 1.5.1.5), and glutamate formiminotransferase (EC 2.1.2.5). The specific activities for methylenetetrahydrofolate reductase were 6.62 +/- 0.51, 4.42 +/- 0.31, and 2.60 +/- 0.40 (nmoles formaldehyde/mg protein/h, mean +/- S.E.) for groups 1, 2 and 3, respectively. The specific activities for the three groups for methionine synthetase were 0.99 +/0 0.11, 0.64 +/- 0.06, and 0.42 +/- 0.05 (nmoles methionine/mg protein/h), mean +/- S.E.). The specific activities for the three groups for glutamine formiminotransferase were 84.1 +/-10.7, 108.6 +/-14.6, and 104.3 +/- 17.8 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). The specific activities for the three groups for methylenetetrahydrofolate dehydrogenase were 0.16 +/- 0.03, 0.39 +/- 0.07, and 0.92 +/- 0.16 (nmoles methenyltetrahydrofolate/mg protein/min, mean +/- S.E.). During development, the specific activities of methylenetetrahydrofolate reductase and methionine synthetase decreased whereas the specific activity of methylenetetrahydrofolate dehydrogenase increased and that of glutamate formiminotransferase remained constant. In addition, the activities of methylenetetrahydrofolate reductase, methionine synthetase, and methylenetetrahydrofolate dehydrogenase were significantly influenced by postnatal age.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗
PubMedDate not supplied

Effects of amino acid dialysis compared to dextrose dialysis in children on continuous cycling peritoneal dialysis.

OBJECTIVE: To compare the biochemical and nutritional effects of amino acid dialysis with dextrose dialysis in children receiving continuous cycling peritoneal dialysis (CCPD). DESIGN: A prospective randomized cross-over study. SETTING: Nonhospitalized patients. PATIENTS: Seven children aged 1.8 to 16.0 years (mean 8.1 years) with end-stage renal disease who were receiving CCPD. INTERVENTIONS: Each patient received nighttime automated CCPD of dextrose, plus a single daytime dwell of either amino acid dialysate or dextrose dialysate. After 3 months, subjects crossed over to the alternative regimen for a subsequent 3 months. MAIN OUTCOME MEASURES: Creatinine clearance, ultrafiltration, urea, creatinine, electrolytes, total protein, albumin, fasting plasma amino acids, anthropometrics, total body nitrogen. RESULTS: Amino acid dialysis was comparable to dextrose dialysis for creatinine clearance and ultrafiltration. Plasma urea concentrations were higher during amino acid dialysis. No clinical side effects or worsening of metabolic acidosis was observed. Caloric intake increased and protein intake improved. Appetite and total body nitrogen increased in at least half the children during amino acid dialysis. Total plasma protein and albumin concentrations did not change significantly. Fasting plasma concentrations of amino acids after 3 months of amino acid dialysis were comparable to baseline values. For several amino acids, the dose-response curve was blunted after a single amino acid exchange following 3 months of amino acid dialysis, which may, in part, be due to the induction of hepatic enzyme synthesis. CONCLUSIONS: Amino acid dialysis is an efficient form of peritoneal dialysis that should be considered for children with poor nutritional status for whom enteral nutrition supplementation has been unsuccessful. Further study is needed to determine the optimal amount of amino acids to deliver, the best time to administer the amino acid dialysis fluid, and the benefits of adding dextrose to the amino acid solution.

Adolescent↗