RESUMO
Milk fatty acids, including the polyunsaturated long chain fatty acids essential for retinal function and brain development, are not affected by pasteurization (62.5 degrees C for 30 min). Milk lipases are completely destroyed by pasteurization, whereas amylase lost only 15% of initial activity. Thus, certain bioactive components are stable to pasteurization of donor milk and can benefit the recipient infants.
Assuntos
Amilases/metabolismo , Ácidos Graxos Insaturados/análise , Lipase/metabolismo , Leite Humano/química , Leite Humano/enzimologia , Esterilização , Cromatografia Gasosa , Feminino , Temperatura Alta/efeitos adversos , Humanos , Bancos de Leite HumanoAssuntos
Lactação/fisiologia , Fenômenos Fisiológicos da Nutrição/fisiologia , Bangladesh , Peso Corporal/fisiologia , Países em Desenvolvimento , Feminino , Gâmbia , Guatemala , Humanos , Leite Humano/química , Leite Humano/metabolismo , Mianmar , Filipinas , Dobras Cutâneas , Suécia , Estados UnidosRESUMO
The use of dietary fat in preference to carbohydrate offers the theoretic advantage of diminishing carbon dioxide production and thus the respiratory quotient, which may be beneficial for babies with chronic lung disease. Ten premature infants (birth weight (mean +/- SEM), 1.13 +/- 0.12 kg; postnatal age, 9 +/- 1 weeks) with bronchopulmonary dysplasia were alternately fed a high-fat and a high-carbohydrate formula each for 1 week, in randomized order. Lower rates of carbon dioxide production (6.6 +/- 0.3 versus 7.4 +/- 0.4 ml/kg per minute; p < 0.05), and consequently lower respiratory quotients (0.80 +/- 0.02 versus 0.94 +/- 0.01 ml/kg per minute; p < 0.005), were observed during the administration of the high-fat formula. There were no significant differences in results of pulmonary function tests with the use of either formula. Both formulas were equally well tolerated and able to promote adequate growth and normal biochemical profiles. However, weight gain was significantly greater with the administration of the high-carbohydrate formula, possibly because of an increase in the accretion of body fat. We conclude that the short-term use of high-fat formula for infants with bronchopulmonary dysplasia decreases carbon dioxide production while maintaining adequate growth and nutritional status.
Assuntos
Displasia Broncopulmonar/dietoterapia , Gorduras na Dieta/administração & dosagem , Alimentos Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido Prematuro/fisiologia , Alimentação com Mamadeira , Displasia Broncopulmonar/metabolismo , Displasia Broncopulmonar/fisiopatologia , Dióxido de Carbono/metabolismo , Carboidratos da Dieta/administração & dosagem , Crescimento , Humanos , Alimentos Infantis/análise , Recém-Nascido , Recém-Nascido Prematuro/metabolismo , Consumo de Oxigênio , Testes de Função RespiratóriaRESUMO
The effect of heparin dose and infusion rate on plasma lipids, lipases, and unbound bilirubin was investigated in 22 premature infants with physiologic jaundice. Infants were randomly assigned to receive low or high intravenous doses (24 vs 137.3 U/day) of heparin. Each patient then received 2 g/kg/day of 10% Intralipid on 2 successive days: one day during a 15-hour period and the other day over 24 hours, with the order assigned randomly. The results demonstrate a significantly greater change in serum-free fatty acids in infants receiving the high heparin dose during the 15-hour lipid infusion period. Lipoprotein lipase activity rose more with the high heparin dose and equally at either infusion rate. We conclude that lipid infusions of 2 g/kg/day with low heparin dosage infused over 24 hours resulted in less elevation in serum-free fatty acids. There were no adverse effects on unbound bilirubin at either infusion rate or heparin dosage.
Assuntos
Bilirrubina/metabolismo , Emulsões Gordurosas Intravenosas/administração & dosagem , Heparina/administração & dosagem , Recém-Nascido de Baixo Peso/metabolismo , Doenças do Prematuro/metabolismo , Metabolismo dos Lipídeos , Esquema de Medicação , Humanos , Recém-Nascido , Doenças do Prematuro/terapia , Infusões Intravenosas/métodos , Icterícia Neonatal/metabolismo , Icterícia Neonatal/terapia , Nutrição Parenteral Total , Distribuição AleatóriaAssuntos
Emulsões Gordurosas Intravenosas/metabolismo , Heparina/administração & dosagem , Recém-Nascido de Baixo Peso , Nutrição Parenteral Total , Nutrição Parenteral , Ácidos Graxos não Esterificados/sangue , Idade Gestacional , Heparina/farmacologia , Humanos , Recém-Nascido , Triglicerídeos/sangueRESUMO
The effect of heparin (10 U/kg) on serum lipolytic activity, triglyceride and FFA levels, during four hours infusion of 0.5 gm/kg Intralipid was measured in 18 AGA infants, 25 to 32 weeks' gestational age. PHLA, TG, and FFA were measured at 0, 10, 30, 120, and 240 minutes of infusion of Intralipid, before and following a bolus of 10 U/kg heparin iv. Lipolytic activity, measured by hydrolysis of activated tri-3H-oleate and expressed in mumol FFA released per milliliter serum per hour, was not detected in serum before heparin administration. Ten minutes after heparin administration peak PHLA was significantly higher in infants of 27 to 32 weeks' gestation than in infants of 25 to 26 weeks' gestation. There was no significant difference in peak PHLA between infants of 27 to 28 and 29 to 32 weeks' gestation. PHLA returned to baseline (zero) two hours after heparin administration in all infants. Infants of 25 to 26 weeks' gestational age had significantly higher concentrations of serum triglycerides before and during Intralipid infusion than in infants of 27 to 32 weeks' gestational age. Although there was a transient rise in FFA 10 and 30 minutes after heparin administration, the levels of FFA and triglycerides were not different at the end of infusion with or without heparin in either group, suggesting that a single bolus of heparin has only a transient effect on Intralipid clearance.
Assuntos
Ácidos Graxos não Esterificados/sangue , Heparina/farmacologia , Recém-Nascido de Baixo Peso , Lipólise/efeitos dos fármacos , Nutrição Parenteral Total , Nutrição Parenteral , Triglicerídeos/sangue , Idade Gestacional , Humanos , Recém-NascidoRESUMO
Lipolytic activity was studied in gastric aspirates of 13 premature infants of birth weight 1,050 to 1,786 gm. All infants received a diet of infant formula fed by gastric tube. Gastric aspirates were collected after irrigating the stomach with 2 to 5 ml sterile saline before regular feeding. Lipolytic activity, tested with doubly labeled 3H glyceryl-14 C tripalmitin substrate, was 55.6 +/- 11.7 n mol/min/ml (range 4.2 to 140). The lipolytic activity had a pH optimum of 5.4 and produced partial glycerides (mono and diglycerides), glycerol, and free fatty acids. Lipolysis was inhibited by bile salts. Our findings show that in premature infants, as in adults, digestion of dietary fat starts in the stomach. Since bile salt concentrations are low in premature infants, the amphiphilic reaction products formed (monoglyceride and FFA) could play a significant role in the stabilization of lipid emulsions.