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Biomedical subjects

J B van Goudoever

Publications and source records attributed to J B van Goudoever.

At least 19 recordsLinked to original sources
PubMed2006

Parenteral amino acid and energy administration to premature infants in early life.

After birth, the nutritional supply through the umbilical cord ceases. Premature infants do not immediately tolerate full enteral feedings, yet they retain high nutritional needs for both growth and metabolic maintenance. Parenteral nutrition should therefore be initiated as quickly as possible after premature birth, thereby reducing the dependence on endogenous substrates. Intrauterine studies show very high amino acid uptake, clearly exceeding accretion rates. Studies covering the early neonatal period demonstrate that the initiation of high-dose amino acid administration directly after birth is safe and effective, even at low energy intakes. Future research should reveal whether usage could be improved through better amino acid solutions or by providing more energy via lipids from birth onwards as well.

Amino Acids, Essential↗
PubMed2005

[A careful course of action in a conflict regarding useful treatment of a newborn infant with severe brain damage].

In a newborn female infant, it was concluded that severe perinatal asphyxia had caused such extensive cerebral damage that further medical treatment was useless. Based on their religious beliefs, the parents disagreed, despite the fact that the requested second opinions supported the conclusion of the medical staff. Since the parents persisted, a period of inurement was agreed upon during which reanimation would be performed if necessary. After several months, there was no change in the attitude of the parents towards the policy not to reanimate, even though it was clear that there was no improvement whatsoever in the patient's neurological status, while everyone agreed that she showed signs of increased suffering. The decision regarding the determination of a situation in which further medical treatment was useless was re-evaluated carefully. In a legal procedure started by the parents, the judge supported the decision of the attending physicians. In order to prevent the parents from taking their child home, in which case a situation could arise in which she would be deprived of adequate sedation or analgesia, which the attending physicians were obliged to provide, the Dutch Child Protection Council was consulted and the parents were deprived of their parental authority. Ultimately, the patient died suddenly due to respiratory and circulatory arrest without another situation in which reanimation might have been indicated.

Brain Damage, Chronic↗
PubMed2005

[Twenty-five week limit for viability of the foetus is too rigid].

The a-priori withholding of treatment from premature infants based on gestational age only (< 25 weeks) puts a number of children born each year who would otherwise benefit from treatment and be able to lead a qualitatively good life at a disadvantage. Treating each case individually is necessary in order to decide if these children are viable.

Fetal Viability↗
PubMed2004

Lysine kinetics in preterm infants: the importance of enteral feeding.

INTRODUCTION: Lysine is the first limiting essential amino acid in the diet of newborns. First pass metabolism by the intestine of dietary lysine has a direct effect on systemic availability. We investigated whether first pass lysine metabolism in the intestine is high in preterm infants, particularly at a low enteral intake. PATIENTS AND METHODS: Six preterm infants (birth weight 0.9 (0.1) kg) were studied during two different periods: period A (n = 6): 40% of intake administered enterally, 60% parenterally; lysine intake 92 (6) micromol/(kg x h); and period B (n = 4): 100% enteral feeding; lysine intake 100 (3) micromol/(kg x h). Dual stable isotope tracer techniques were used to assess splanchnic and whole body lysine kinetics. RESULTS: Fractional first pass lysine uptake by the intestine was significantly higher during partial enteral feeding (period A 32 (10)% v period B 18 (7)%; p<0.05). Absolute uptake was not significantly different. Whole body lysine oxidation was significantly decreased during full enteral feeding (period A 44 (9) v period B 17 (3) micromol/(kg x h); p<0.05) so that whole body lysine balance was significantly higher during full enteral feeding (period A 52 (25) v period B 83 (3) micromol/(kg x h); p<0.05). CONCLUSIONS: Fractional first pass lysine uptake was much higher during partial enteral feeding. Preterm infants receiving full enteral feeding have lower whole body lysine oxidation, resulting in a higher net lysine balance, compared with preterm infants receiving partial enteral feeding. Hence parenterally administered lysine is not as effective as dietary lysine in promoting protein deposition in preterm infants.

Dietary Proteins↗
PubMed2001

The pattern of intestinal substrate oxidation is altered by protein restriction in pigs.

BACKGROUND & AIMS: Previous studies indicate that amino acids and glucose are the major oxidative substrates for intestinal energy generation. We hypothesized that low protein feeding would lower the contribution of amino acids to energy metabolism, thereby increasing the contribution of glucose. METHODS: Piglets, implanted with portal, arterial, and duodenal catheters and a portal flow probe, were fed isocaloric diets of either a high protein (0.9 g/[kg/h] protein, 1.8 g/[kg/h] carbohydrate, and 0.4 g/[kg/h] lipid) or a low protein (0.4 g/[kg/h] protein, 2.2 g/[kg/h] carbohydrate, and 0.5 g/[kg/h] lipid) content. They received enteral or intravenous infusions of [1-13C]leucine (n = 17), [U-13C]glucose (n = 15), or enteral [U-13C]glutamate (n = 8). RESULTS: CO2 production by the splanchnic bed was not affected by the diet. The oxidation of leucine, glutamate, and glucose accounted for 82% of the total CO2 production in high protein-fed pigs. Visceral amino acid oxidation was substantially suppressed during a low protein intake. Although glucose oxidation increased to 50% of the total visceral CO2 production during a low protein diet, this increase did not compensate entirely for the fall in amino acid oxidation. CONCLUSIONS: Although low protein feeding increases the contribution of enteral glucose oxidation to total CO2 production, this adaptation is insufficient. To compensate for the fall in amino acid oxidation, other substrates become increasingly important to intestinal energy generation.

Animals↗
PubMed2001

Secretion of trophic gut peptides is not different in bolus- and continuously fed piglets.

In neonates, bolus feeding is associated with greater rates of intestinal growth than is continuous feeding. We tested whether the concentrations and secretion rates of trophic gut peptides are higher in bolus-fed than in continuously fed piglets. Five 21-d-old piglets were surgically implanted with gastric, arterial and portal catheters and a portal blood flow probe. At postnatal d 30 and 31, pigs received an equal amount of primed continuous or bolus feeding of a cow's milk formula in a randomized, crossover design. During a 6-h period, portal blood flow and arterial and portal concentrations of glucagon-like peptide-2 (GLP-2), peptide YY (PYY) and gastric inhibitory polypeptide (GIP) were measured. All hormone levels were significantly increased within 1 h of the start of the experiment, independent of the feeding modality. There were no differences between bolus and continuous feeding in either the arterial concentrations or secretion rates of GLP-2, PYY and GIP. In both treatment groups, the increases in the plasma concentrations of GLP-2 and GIP after feeding were substantially greater than those for PYY. We conclude that the production or circulating concentrations of GLP-2, PYY and GIP are not significantly different in bolus- and primed continuously fed piglets.

Animals↗
PubMed2001

Leucine kinetics during simultaneously administered insulin and dexamethasone in preterm infants with severe lung disease.

The objective of this study was to determine whether insulin administration would prevent the well-documented catabolic effect of dexamethasone given to preterm infants with chronic lung disease. We studied leucine metabolism in 11 very-low-birth-weight infants before dexamethasone treatment and on d 2, 4, and 7 thereafter. During the first 4 d of dexamethasone, insulin was administered i.v. at a dose of 0.5 (n = 7) or 1.0 (n = 5) IU/kg/d. Leucine turnover was not significantly different between d 0 (337 +/- 41.3 micromol leucine/kg/h), d 2 (288 +/- 27.2 micromol leucine/kg/h), d 4 (302 +/- 22.1 micromol leucine/kg/h), and d 7 (321 +/- 21.2 micromol leucine/kg/h), and neither was leucine breakdown (272 +/- 21.9 micromol leucine/kg/h on d 0, 225 +/- 21.5 micromol leucine/kg/h on d 2, 231 +/- 21 micromol leucine/kg/h on d 4, and 242 +/- 17.6 micromol leucine/kg/h on d 7). Weight gain rates were significantly lower during the first week of dexamethasone treatment compared with the week before treatment or the second and third week. We conclude that during insulin and corticosteroid administration in very-low-birth-weight infants, no changes were observed in leucine kinetics in contrast to previous studies. The decrease in weight gain was not reversed.

Anti-Inflammatory Agents↗
PubMed2000

Adaptive regulation of intestinal lysine metabolism.

The metabolism of dietary essential amino acids by the gut has a direct effect on their systemic availability and potentially limits growth. We demonstrate that, in neonatal pigs bearing portal and arterial catheters and fed a diet containing 23% protein [high protein (HP) diet], more than half the intake of essential amino acids is metabolized by the portal-drained viscera (PDV). Intraduodenal or i.v. infusions of [U-(13)C]-lysine were used to measure the appearance across and the use of the tracer by the PDV. In HP-fed pigs, lysine use by the PDV was derived almost entirely from the arterial input. In these animals, the small amount of dietary lysine used in first pass was oxidized almost entirely. Even so, intestinal lysine oxidation (24 micromol/kg per h) accounted for one-third of whole-body lysine oxidation (77 micromol/kg per h). Total lysine use by the PDV was not affected by low protein (LP) feeding (HP, 213 micromol/kg per h; LP,186 micromol/kg per h). In LP-fed pigs, the use of lysine by the PDV accounted for more than 75% of its intake. In contrast to HP feeding, both dietary and arterial lysines were used by the PDV of LP-fed pigs in nearly equal amounts. Intestinal lysine oxidation was suppressed completely. We conclude that the PDV are key organs with respect to amino acid metabolism and that the intestines use a disproportionately large amount of the dietary supply of amino acids during protein restriction.

Adaptation, Physiological↗
PubMed2000

Protein nutrition of the neonate.

The period of growth and development between birth and weaning is crucial for the long-term well-being of the organism. Protein deposition is very rapid, is achieved with a high nutritional efficiency, and is accompanied by marked differences in the growth rates of individual tissues and a series of maturational processes. These important aspects of development occur while the neonate is consuming a single and highly-specific food source, milk. Surprisingly, although there is a clear relationship between the nutrient density of milk and the growth rate of its recipient, this relationship does not apply to the overall amino acid composition of mixed milk proteins. Some amino acids, notably glycine and arginine, are supplied in milk in quantities that are much less than the needs of the neonate. The milk-fed neonate is therefore capable of carrying out a tightly-regulated transfer of N from amino acids in excess to those that are deficient. The rapid growth of the neonate is supported by a high rate of tissue protein synthesis. This process appears to be activated by the consumption of the first meals of colostrum. Recent research has identified that skeletal muscle and the brain are specifically responsive to an unidentified factor in colostrum. Following the initial anabolic response the rate of protein synthesis in some tissues, notably muscle, falls from birth to weaning. This decrease reflects a progressively smaller anabolic response to nutrient intake, which not only involves an overall fall in the capacity for protein synthesis, but also in responses to insulin and amino acids. The study of growth and protein metabolism, and their regulation in the neonate is not only important for pediatrics, but may provide important pointers to more general aspects of regulation that could be applied to the nutrition of the mature animal.

Amino Acids↗
PubMed2000

Short-term growth and substrate use in very-low-birth-weight infants fed formulas with different energy contents.

BACKGROUND: Currently available preterm formulas with energy contents of 3350 kJ (800 kcal)/L promote weight and length gain at rates at or above intrauterine growth rates but disproportionately increase total body fat. OBJECTIVE: The objective of this study was to determine whether fat accretion in formula-fed, very-low-birth-weight (VLBW) infants could be decreased and net protein gain maintained by reducing energy intakes from 502 kJ (80 kcal)*kg(-)(1)*d(-)(1) [normal-energy (NE) formula] to 419 kJ (100 kcal)*kg(-)(1)*d(-)(1) [low-energy (LE) formula] while providing similar protein intakes (3.3 g*kg(-)(1)*d(-)(1)). DESIGN: The study was a randomized, controlled trial enrolling 20 appropriate-for-gestational-age (AGA) and 16 small-for-gestational-age (SGA) VLBW infants (mean birth weight: 1.1 kg; mean gestational age: 31 wk); energy expenditure and nutrient balance were measured at 4 wk of age and anthropometric measurements were made when infants weighed 2 kg. RESULTS: The percentage of fat in newly formed tissue was significantly lower in AGA infants fed the LE formula (n = 9) than in those fed the NE formula (n = 10) (9% compared with 23%; analysis of variance, P = 0.001). Energy expenditure was higher in AGA infants fed the NE formula than in those fed the LE formula. Skinfold thickness was markedly lower in AGA infants fed the LE formula than in those fed the NE formula, resulting in a lower estimated percentage body fat (8.0 +/- 1.9% and 10.8 +/- 3.5%, respectively; P < 0.05). Three of 6 SGA infants fed the LE formula were excluded during the study because of poor weight gain. CONCLUSIONS: Body composition can easily be altered by changing the energy intakes of formula-fed VLBW infants. Energy intakes in these infants should be >419 kJ (100 kcal)*kg(-)(1)*d(-)(1).

Adipose Tissue↗
PubMed1995

Feeding premature newborn infants palmitic acid in amounts and stereoisomeric position similar to that of human milk: effects on fat and mineral balance.

The effect of the structure of human milk triglycerides on intestinal fat absorption remains controversial. Twelve infants were each fed, for 1 wk in a crossover design, two formulas that differed only in triglyceride configuration. The "beta" formula contained triglycerides similar to those in human milk (26% palmitic acid, esterified predominantly to the sn-2 position) whereas in the "alpha" formula, which contained triglycerides similar to those in formulas currently marketed, palmitate was mainly at the sn-1,3 positions. Fatty acid, fat, and mineral balances were measured at the end of each 1-wk period. Myristic, palmitic, and stearic acids were absorbed better from the beta formula, but total fat excretion was not reduced. During the feeding of beta formula fecal calcium excretion was lower, urinary calcium higher, and urinary phosphate lower. A formula containing triglycerides similar to those in human milk has significant effects on fatty acid intestinal absorption and improves mineral balance in comparison with a conventional formula.

Administration, Oral↗
PubMed1994

Conversion of octanoic acid into long-chain saturated fatty acids in premature infants fed a formula containing medium-chain triglycerides.

A large number of very-low-birth weight infants are fed formulas containing medium-chain triglycerides (MCT) to enhance fat and calcium absorption. Studies are available on the intestinal absorption of MCT, which is nearly complete, but uncertainties exist on the metabolic fate of octanoic acid, the major component of MCT. Oxidation accounts for approximately 50% of the dietary intake, and losses as dicarboxylic acids in the urine are negligible. Since storage in adipose tissue is limited, conversion into long-chain fatty acids (LCFA) is likely to be an important route. To study the nonoxidative metabolism of MCT, six preterm infants fed a standard premature formula containing 38 weight% (wt%) MCT (54 mol% medium-chain fatty acids (MCFA), of which 35 mol% is octanoic acid) were studied at 4 weeks of age, when on full oral intake and receiving on average 130 kcal/kg/d. The study consisted of an oral primed constant-rate infusion of [13C]-octanoate and the measurement of the 13C enrichment of individual fatty acids in plasma triglycerides (TG) by a highly sensitive on-line combustion method using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). We observed a significant incorporation of the dietary [13C]-octanoic acid in plasma TG (10.0% +/- 4.5% of the enrichment of the diet). A noticeable incorporation of the label was detected in myristic and palmitic acids (4.6% +/- 2.5% and 7.8% +/- 4.1% of the octanoic enrichment of the diet). The absolute amount of the fatty acids was studied with conventional GC, and the plasma TG fatty acid profile differed markedly from the diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Caprylates↗
PubMed1994

Substrate utilization during the first weeks of life.

It is assumed that substrate utilization changes markedly around birth, from mainly glucose utilization before, to glucose/fat utilization after birth. We studied substrate oxidation and turnover in preterm infants on the first day and during the first weeks of life. We found that only part of the glucose that is infused on the first day of life is oxidized, while glucose is also converted into fat at the same time. Almost half of the energy expenditure is provided by fat oxidation on day 7 and 28 of life. Fat oxidation is dependent on the type of fat oxidized; the rate of oxidation of medium chain triglycerides (MCT) is higher than that of long chain fatty acids. MCT can replace glucose as an energy source. Proteins contribute only to a small extent (approximately 7%) to the energy expenditure at all ages.

Energy Metabolism↗
PubMed1993

Glucose metabolism in a term infant with transient hyperinsulinism and high carbohydrate intake.

Transient hyperinsulinaemia is a well-known cause of hypoglycaemia in newborn infants. The hypoglycaemia may be caused by a decreased glucose production and/or an increased glucose uptake. Whether the increased uptake is caused by increased glucose oxidation or increased non-oxidative disposal is not known. The aim of this study was to investigate the fate of the large amount of glucose infused in a term infant who developed hypoglycaemia due to transient hyperinsulinaemia shortly after birth and was treated with high glucose infusions. On day 6 an indirect calorimetry study was performed, together with a glucose turnover study. Carbohydrate intake was 13.6 mg/kg per minute (19.6 g/kg per day). Both studies were repeated on day 11, when carbohydrate intake was normalised to 7.8 mg/kg per minute (11.2 g/kg per day). Glucose oxidation was 28% higher and non-oxidative glucose disposal was 257% higher on day 6 as compared to day 11. Our results indicate that hypoglycaemia during hyperinsulinism is the result of increased non-oxidative disposal of glucose and not increased glucose oxidation. The results indicate a remarkable capacity of the newborn for lipogenesis during high carbohydrate intake.

Adipose Tissue↗
PubMed1993

Decreased glucose oxidation in preterm infants fed a formula containing medium-chain triglycerides.

Several formulas for preterm infants contain medium-chain triglycerides (MCT) to enhance fat absorption. Although fat absorption with MCT was slightly higher in several studies in preterm infants, a beneficial effect on growth has only been reported in one publication. We hypothesized that when part of the fat blend of preterm formula is substituted by MCT oil, this might lead to a different metabolic pattern in which, due to the preferential oxidation of MCT, an increase in lipogenesis from glucose could lead to an increase in metabolic rate. To study the impact of MCT on glucose metabolism, 18 preterm infants were randomized to receive either an MCT or an LCT formula containing 38- and 6%-by-weight medium-chain fatty acids, respectively, in their fat blend. At 4 wk of age, the metabolic rate, substrate utilization, glucose kinetics, and oxidation were measured by indirect respiratory calorimetry in combination with a constant-rate oral infusion of [U-13C]glucose. The "true" rate of appearance of glucose (Ra "true") was measured from the dilution of the uniformly labeled (m + 6) species of infused tracer, whereas "apparent" rate of appearance of glucose (Ra "apparent") was measured from the dilution of infused tracer C (carbon). The latter was measured by an on-line combustion method using a gas chromatograph-isotope ratio mass spectrometer. At a carbohydrate intake of 8.4 mg.kg-1.min-1, total utilization of carbohydrate was equal in both groups at 7.6 mg.kg-1.min-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary Carbohydrates↗
PubMed1993

Glucose kinetics and glucoregulatory hormone levels in ventilated preterm infants on the first day of life.

Glucose production and oxidation were measured in ventilated preterm appropriate-for-gestational-age and small-for-gestational-age infants on the first day of life. Using a new technique of NaH13CO3 infusion followed by a [U-13C]glucose infusion, we measured glucose oxidation rates without measuring the CO2 production rate. Infants were studied at 18 +/- 4 h (mean +/- 1 SD) of life and received parenterally administered glucose only (4.2 +/- 0.5 mg.kg-1 x min-1). In 13 of 16 patients, the glucose production rate exceeded 1.0 mg.kg-1 x min-1. Infants born from mothers who had been receiving steroids antenatally had higher glucose production rates (2.3 +/- 1.1 mg.kg-1 x min-1) compared with infants from mothers who had not (1.1 +/- 0.8 mg.kg-1 x min-1, p = 0.036). The glucose oxidized (2.9 +/- 1.0 mg.kg-1 x min-1) was lower than the amount of glucose infused (p = 0.005) and was not different for appropriate-for-gestational-age and small-for-gestational-age infants. Plasma levels of glucose, insulin, glucagon, and total IGF-I were not correlated with glucose metabolism on the first day of life. Total IGF-II levels were negatively correlated with the rate of glucose appearance. We conclude that preterm infants on the first day of life receiving a glucose infusion of 4.2 mg.kg-1 x min-1 continue to produce glucose. The glucose oxidation rate is lower than the glucose infusion rate and the contribution of glucose oxidation to the total energy expenditure is limited.

Blood Glucose↗