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Pieter J J Sauer

Publications and source records attributed to Pieter J J Sauer.

At least 19 recordsLinked to original sources
PubMed2006

Energy requirements.

The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an appropriate amount of energy to newborn infants remains a challenge considering the great number of newborn infants who suffer in-hospital growth retardation. The energy requirements of a newborn infant are influenced by several factors - basal metabolism, growth, energy expenditure, and energy losses - which change continuously during development. Calculating the energy requirements of preterm infants is subject to error if general recommendations are applied without recognition of the large variation in factors that influence, for example, energy expenditure. Therefore, energy recommendations should be individualized and preferably based on measurements of energy expenditure. In particular, extremely low birth-weight and very low birth-weight infants are prone to develop negative energy and nutrient balances, due to low energy intake, low energy reserves and high energy demands. Early energy accretion is not only essential for growth but also influences neurodevelopmental outcome and physical health in the long term, thereby underlining the importance of adequate neonatal nutrition.

Energy Metabolism↗
PubMed2006

Nonabsorbable dietary fat enhances disposal of 2,2',4,4'-tetrabromodiphenyl ether in rats through interruption of enterohepatic circulation.

Polybrominated diphenyl ethers are lipophilic persistent organic pollutants (POPs), which accumulate in the environment, leading to human exposure. The compounds exert a negative impact on human health. Strategies to prevent or diminish their accumulation in humans are required. We investigated in rats whether the disposal rate of 14C-labeled tetrabromodiphenyl ether (BDE-47) could be enhanced by increasing fecal fat excretion through dietary treatment with nonabsorbable fat (sucrose polyester, SPE). As compared to control rats, SPE treatment increased fecal excretion rates of fat (+188%, p < 0.05) and 14C-BDE-47 (+291%, p < 0.05). On the basis of biliary secretion and fecal excretion rates of 14C-BDE-47, SPE effectively inhibited the enterohepatic circulation of 14C-BDE-47. In conclusion, dietary supplementation of nonabsorbable fat can enhance excretion of hydrophobic POPs by interruption of their enterohepatic circulation. Our data indicate that this strategy could decrease concentrations of hydrophobic POPs in the human body and thereby their impact on human health.

Animals↗
PubMed2006

The natural history of medium-chain acyl CoA dehydrogenase deficiency in the Netherlands: clinical presentation and outcome.

OBJECTIVES: To describe the clinical presentation and long-term follow-up of a large cohort of patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. STUDY DESIGN: A nationwide, retrospective analysis of clinical presentation and follow-up in 155 Dutch patients with MCAD deficiency. RESULTS: Most patients presented between 3 months and 5.1 years of age; 13% had symptoms as neonates not exclusively related to breast-feeding. An acute presentation before the diagnosis was made resulted in a mortality of 22% (25/114), whereas 21% (19/89) developed disabilities after the diagnosis. On follow-up, a total of 44 patients reported fatigue (35%; 28/80), muscle pain (31%; 25/80), and/or reduced exercise tolerance (39%; 31/80). Cardiac evaluation in 11 adult patients revealed no abnormalities in cardiac function explaining these complaints. Children with MCAD deficiency readily become overweight. CONCLUSIONS: Mortality and morbidity were high in undiagnosed children with MCAD deficiency; establishment of the diagnosis significantly improves outcome. Strikingly, after the diagnosis and initiation of treatment, overweight and chronic complaints (fatigue, muscle pain, and reduced exercise tolerance) were prominent.

Acyl-CoA Dehydrogenase↗
PubMed2006

Low lactase activity in a small-bowel biopsy specimen: should dietary lactose intake be restricted in children with small intestinal mucosal damage?

OBJECTIVE: Small intestinal mucosal damage can result in decreased lactase activity (LA). When LA is low in a small-bowel biopsy (SBB) specimen, a reduction of dietary lactose intake is usually advised. This is often done by reducing dietary dairy products, which also reduces the intake of calcium, protein and vitamins. Since intestinal damage can have a patchy character and LA varies along the horizontal axis of the small intestine, the relevance of SBB measurement for intestinal LA could be questioned. We compared LA in the SBB with the in vivo capacity to digest lactose using the Lactose Digestion Index (LDI). MATERIAL AND METHODS: LA was measured in 18 children aged 0.8-10.9 years (mean 3.9, SD 2.4) undergoing SBB for various indications. In all children the LDI was determined using the (13)C-lactose/(2)H-glucose test. RESULTS: In 9/18 biopsy specimens LA was low (<10 U/g protein). LDI was normal in 14/18 patients. In 8 out of 9 patients with normal lactase activity, LDI was also normal, while in 6 out of 9 patients LDI was normal despite low LA in the biopsy. In patients with normal LDI, histology was normal in 6/14, in 4/14 mild histological changes (Marsh II) were seen and in 4 patients histological damage was severe (grade III). CONCLUSIONS: In children with small-bowel mucosal damage, lactose digestive capacity can remain high despite low LA and histological changes in an SBB. Extrapolation of LA in SBB specimens to overall lactose digestive capacity may not be reliable. The advice concerning the restriction of intake of dairy products cannot be based on the data of the SBB only.

Biopsy↗
PubMed2005

Effect of two amino acid solutions on leucine turnover in preterm infants.

OBJECTIVE: To assess the effect of two different parenteral amino acid mixtures, Trophamine and Primene, on leucine turnover in preterm infants. METHOD: Leucine kinetics were measured with [5,5,5 D3]leucine tracer in 15 infants receiving Trophamine (group 'T') (mean birth weight 1,263 g) and 22 who received Primene (group 'P') (mean birth weight 1,336 g) during two study periods, within a few hours after birth but before introduction of parenteral amino acid solution, and again at postnatal day 7. The rate of appearance of leucine was calculated from the enrichment of alpha-ketoisocaproic acid in plasma. RESULTS: There were no significant differences in leucine turnover within a few hours after birth in the two groups. In the infants who received Primene leucine turnover on day 7 was significantly lower than in those who received Trophamine (269 +/- 43 vs. 335 +/- 27, p < 0.05). Despite a higher intake of leucine in the Trophamine group (108 +/- 10 vs. 77 +/- 8 micromol.kg(-1).h(-1)), leucine released from proteins at day 7 was higher in this group compared to Primene (227 +/- 27 vs. 192 +/- 42 micromol.kg(-1).h(-1)). CONCLUSIONS: Primene administration results in lower leucine released from proteins, an estimate of protein breakdown, than Trophamine in preterm infants. Increases in whole body leucine turnover in response to administration of i.v. amino acids is influenced by the composition of the amino acid mixture. The factors responsible for this difference remain to be elucidated.

Amino Acids↗
PubMed2005

A randomized, placebo-controlled GH trial in very preterm infants who were at risk for bronchopulmonary dysplasia and were treated with dexamethasone.

Very preterm infants who develop bronchopulmonary dysplasia are often treated with dexamethasone (DEXA) to wean them from the ventilator. As DEXA has growth-suppressive and catabolic effects, which might have long-term consequences on growth and organ development, we investigated whether high-dose GH treatment could overcome these effects. In a randomized, double-blind, placebo-controlled trial, 30 ventilated very low birth weight infants were assigned to receive either GH or placebo treatment after start of DEXA. DEXA was given for 24 d (starting dose 0.5 mg . kg(-1) . d(-1), tapering off every third day). Simultaneously, high-dose GH (0.3 mg . kg(-1) . d(-1)) or placebo was administered during 6 wk. During high-dose DEXA treatment (dose 0.5-0.3 mg . kg(-1) . d(-1)), no gain in head circumference, weight, crown-heel length, and knee-heel length occurred in the GH and placebo groups. Growth during the 6-wk study period was not different between the GH and the placebo groups. Two patients in the placebo group died, but the number and the severity of adverse effects was not statistically different between the GH and placebo groups. In conclusion, high-dose GH treatment did not improve growth in DEXA-treated very preterm infants and thus cannot be recommended to prevent growth failure in these infants. During high-dose DEXA, a complete growth arrest occurred, including stunting of head growth. Growth in head circumference and weight with lower dose DEXA was comparable to growth after discontinuation of DEXA.

Anti-Inflammatory Agents↗
PubMed2004

Cholesterol synthesis and de novo lipogenesis in premature infants determined by mass isotopomer distribution analysis.

Premature infants change from placental supply of mainly carbohydrates to an enteral supply of mainly lipids earlier in their development than term infants. The metabolic consequences hereof are not known but might have long-lasting health effects. In fact, knowledge of lipid metabolism in premature infants is very limited. We have quantified de novo lipogenesis and cholesterogenesis on d 3 of life in seven premature infants (birth weight, 1319 +/- 417 g; gestational age, 30 +/- 2 wk). For comparison, five healthy adult subjects were also studied. All subjects received a 12-h [1-(13)C] acetate infusion, followed by mass isotopomer distribution analysis (MIDA) on lipoprotein-palmitate and plasma unesterified cholesterol. The fraction of lipoprotein-palmitate synthesized at the end of the infusion period was 5.4 +/- 3.9% in infants, which was in the same range as found in adult subjects on a normal diet, suggesting that hepatic de novo lipogenesis is not a major contributor to fat accumulation in these premature neonates. The fractional contribution of newly synthesized cholesterol to plasma unesterified cholesterol was 7.4 +/- 1.3% after a 12-h infusion. The calculated rate of endogenous cholesterol synthesis was 31 +/- 7 mg/kg/d, a value approximately three times higher than that found in adult subjects (10 +/- 6 mg/kg/d). These results indicate that the cholesterol-synthesizing machinery is well developed in premature infants.

Acetates↗
PubMed2004

Cyclosporine A-induced reduction of bile salt synthesis associated with increased plasma lipids in children after liver transplantation.

Hyperlipidemia is a common side effect of cyclosporine A (CsA) after solid organ transplantation. CsA also markedly reduces the synthesis rate of bile salts in rats and can inhibit biliary bile salt secretion. It is not known, however, whether CsA inhibits the synthesis of bile salts in humans, and whether the hyperlipidemic effects of CsA are related to bile salt metabolism. Our objective was to assess the effects of CsA on the synthesis rate of bile salts and on plasma triglycerides and cholesterol levels in pediatric liver transplant patients. Before and after discontinuation of CsA treatment after liver transplantation, synthesis rate and pool size of the primary bile salts cholate and chenodeoxycholate were determined using a stable isotope dilution technique and related to plasma lipids. In 6 children (age: 3-16 years) CsA treatment was discontinued at 2 years (median 2.3 years) after liver transplantation. Discontinuation of CsA increased synthesis rate of chenodeoxycholate (+38%, P <.001) and cholate (+21%, P <.05) and the pool size of chenodeoxycholate (+54%, P <.001). Discontinuation of CsA decreased plasma levels of cholesterol (-18%, P <.05) and triglycerides (-23%, P <.05). Bile salt synthesis rate appeared to be inversely correlated with plasma cholesterol (Spearman rank correlation coefficient [r(s)] = -0.82, P <.01) and plasma triglyceride levels (r(s) = -0.62, P <.05). In conclusion, CsA inhibits bile salt synthesis and increases plasma concentration of cholesterol and triglycerides in pediatric liver transplant patients. Suppression of bile salt synthesis by long-term CsA treatment may contribute to hyperlipidemia and thus to increased risk for cardiovascular disease.

Adolescent↗
PubMed2004

Effects of antenatal steroids on protein metabolism in preterm infants on the first day of life.

OBJECTIVE: To analyze, in an existing cohort of infants, whether antenatal administered corticosteroids influence protein metabolism in preterm infants on the first day of life. Study design Three groups of infants were studied. The mothers of 25 infants had received 2 or more doses of corticosteroids, the mothers of 5 had received 1 dose, and there was no antenatal steroid exposure for 8 infants. Within a few hours after birth, a double-tracer leucine infusion was started by intravenous and intragastric routes and continued for 5 hours while the infants received only intravenous glucose. RESULTS: The plasma alpha-keto-isocaproic acid (KIC) enrichment (mol percent excess, MPE) from the intravenous tracer was not different between infants who reveived no antenatal steroids (8.58+/-1.64), 1 dose (7.60+/-0.78), and 2 or more doses (7.61+/-1.29). From the intragastric tracer, the plasma KIC enrichment from the intragastric tracer was different among the 3 groups, 7.62+/-2.35 for 0 doses, 5.78+/-0.85 for 1 dose, and 5.53+/-1.58 for 2 or more doses of antenatal steroids. Plasma KIC enrichment from the intravenous tracer was significantly higher than from the intragastric tracer in infants who received antenatal steroids, whereas there was no difference in infants who had not received antenatal steroids. Plasma leucine enrichment showed the same results. CONCLUSIONS: Antenatal corticosteroid administration to the fetus has no effect on whole-body leucine metabolism on the first day of life. However, it is associated with an increase in splanchnic leucine uptake at birth.

Betamethasone↗
PubMed2004

Neonatal loss of motor function in human spina bifida aperta.

OBJECTIVE: In neonates with spina bifida aperta (SBA), leg movements innervated by spinal segments located caudal to the meningomyelocele are transiently present. This study in neonates with SBA aimed to determine whether the presence of leg movements indicates functional integrity of neuronal innervation and whether these leg movements disappear as a result of dysfunction of upper motor neurons (axons originating cranial to the meningomyelocele) and/or of lower motor neurons (located caudal to the meningomyelocele). METHODS: Leg movements were investigated in neonates with SBA at postnatal day 1 (n = 18) and day 7 (n = 10). Upper and lower motor neuron dysfunction was assessed by neurologic examination (n = 18; disinhibition or inhibition of reflexes, respectively) and by electromyography (n = 12; absence or presence of denervation potentials, respectively). RESULTS: Movements, related to spinal segments caudal to the meningomyelocele, were present in all neonates at postnatal day 1. At day 1, leg movements were associated with signs of both upper (10 of 18) and lower (17 of 18) motor neuron dysfunction caudal to the meningomyelocele. In 7 of 10 neonates restudied after the first postnatal week, leg movements had disappeared. The absence of leg movements coincided with loss of relevant reflexes, which had been present at day 1, indicating progression of lower motor neuron dysfunction. CONCLUSIONS: We conclude that the presence of neonatal leg movements does not indicate integrity of functional lower motor neuron innervation by spinal segments caudal to the meningomyelocele. Present observations could explain why fetal surgery at the level of the meningomyelocele does not prevent loss of leg movements.

Electromyography↗
PubMed2003

Effect of dexamethasone treatment on serum GH, IGF-I, and the binding proteins IGFBP-1 and -3 in ventilated very preterm infants.

Very preterm infants developing bronchopulmonary dysplasia frequently show a compromised growth in the neonatal period especially when steroids are given to facilitate weaning from the ventilator. The aim of this study was to evaluate the short-term effect of dexamethasone (DEXA) on the GH-IGF axis in ventilated very preterm infants developing bronchopulmonary dysplasia. We studied 10 very preterm artificially ventilated infants with bronchopulmonary dysplasia [median (range) gestational age 27.5 wk (25.9-32.0 wk), median (range) birth weight 970 g (610-2150 g)] immediately before and 2 d after the start of DEXA treatment. On both days of study, serum GH profiles were obtained, and serum IGF-I and IGF binding protein (IGFBP) -1 and -3 levels were measured. The ventilation score and the nutritional intake were calculated. Before the start of DEXA treatment, the median serum mean GH level was 12.0 microg/L (6-28.4 microg/L), whereas 2 d after the start of DEXA treatment the median serum mean GH level declined significantly to a value of 4.4 microg/L (1.7-11.9 microg/L). During DEXA treatment, mean, baseline, and maximal GH levels (Pulsar analysis) were significantly lower compared with pretreatment levels (p < 0.01, p < 0.01, and p < 0.05, respectively). Serum IGF-I and IGFBP-3 levels did not decline during DEXA. Serum IGFBP-1 levels were significantly lower compared with pretreatment levels (p < 0.01). Serum GH levels during DEXA treatment were correlated with neither the time interval between the administration of DEXA and the second GH profile nor the cumulative DEXA dose administered. Ventilation score and nutritional intake did not significantly correlate with serum GH, IGF-I, or IGFBP-1 or -3 levels, either before or after the start of DEXA. Two days of DEXA treatment in very preterm ventilated infants has a suppressive effect on serum GH levels, without an acute decline in serum IGF-I levels. A concomitant decrease in serum IGFBP-1 levels was found.

Bronchopulmonary Dysplasia↗
PubMed2003

Evaluation of the WHO clinical case definition for pediatric HIV infection in Bloemfontein, South Africa.

The WHO clinical case definition for pediatric HIV infection has been designed to be used in countries where diagnostic laboratory resources are limited. We evaluated the WHO case definition to determine whether it is a useful instrument to discriminate between HIV-positive and HIV-negative children. In addition, clinical features not included in this case definition were recorded. We recorded clinical data from 300 consecutively admitted children in a state hospital in Bloemfontein, South Africa, and tested these children for HIV infection. A total of 222 children were included in the study; 69 children (31.1 per cent) were HIV positive. The sensitivity of the WHO case definition in this study was 14.5 per cent, the specificity was 98.6 per cent. Apart from weight loss and generalized dermatitis, the signs of the WHO case definition were significantly more often seen in HIV-positive than in HIV-negative children. Of the clinical signs not included in the WHO case definition, marasmus and hepatosplenomegaly especially occurred more frequently in HIV-positive children. Based on these findings we composed a new case definition consisting of four signs: marasmus, hepatosplenomegaly, oropharyngeal candidiasis, and generalized lymphadenopathy. HIV infection is suspected in a child presenting with at least two of these four signs. The sensitivity of this case definition was 63.2 per cent, the specificity was 96.0 per cent. We conclude that in this study the WHO case definition was not a useful instrument to discriminate between HIV-positive and HIV-negative children, mainly because its sensitivity was strikingly low. The simplified case definition we propose, proved to be more sensitive than the WHO case definition (63.2 vs. 14.5 per cent), whilst its specificity remained high.

AIDS-Related Opportunistic Infections↗
PubMed2003

Cyclosporin a and enterohepatic circulation of bile salts in rats: decreased cholate synthesis but increased intestinal reabsorption.

Cyclosporin A (CsA) has been shown to inhibit synthesis and hepatobiliary transport of bile salts. However, effects of CsA on the enterohepatic circulation of bile salts in vivo are largely unknown. We characterized the effects of CsA on the enterohepatic circulation of cholate, with respect to synthesis rate, pool size, cycling time, intestinal absorption, and the expression of relevant transporters in liver and intestine in rats. CsA (1 mg. 100 g(-1). day(-1) s.c.) or its solvent was administered daily to male rats for 10 days. Cholate synthesis rate and pool size were determined by a 2H4-cholate dilution technique. Bile and feces were collected for determination of cholate and total bile salts, respectively. Cycling time and intestinal absorption of cholate were calculated. The mRNA levels and corresponding transporter protein levels in liver and intestine were assessed by real-time polymerase chain reaction and Western analysis, respectively. CsA treatment decreased cholate synthesis rate by 71%, but did not affect pool size or cycling time. CsA reduced the amount of cholate lost per enterohepatic cycle by approximately 70%. Protein levels of the apical sodium-dependent bile salt transporter (Asbt) were 2-fold increased in distal ileum of CsA-treated rats, due to post-transcriptional events. In conclusion, chronic CsA treatment markedly reduces cholate synthesis rate in rats, but does not affect cholate pool size or cycling time. Our results strongly suggest that CsA enhances efficacy of intestinal cholate reabsorption through increased Asbt protein expression in the distal ileum, which contributes to maintenance of cholate pool size in CsA-treated rats.

Animals↗
PubMed2003

Effect of minimal enteral feeding on splanchnic uptake of leucine in the postabsorptive state in preterm infants.

We conducted a controlled, randomized trial to study the effect of minimal enteral feeding on leucine uptake by splanchnic tissues, as an indicator of maturation of these tissues, in preterm infants in the first week of life. Within a few hours after birth, while receiving only glucose, a primed constant infusion of [1-(13)C]-leucine was started and continued for 5 h via the nasogastric tube, whereas 5,5,5 D3-leucine was infused intravenously (for both tracers, priming dose 2 mg/kg, continuous infusion 2 mg/kg/h). Patients were thereafter randomized to receive solely parenteral nutrition (C), parenteral nutrition and 20 mL breast milk/kg/d (BM), or parenteral nutrition and 20 mL formula/kg/d (F). On d 7, the measurements were repeated, after discontinuing the oral intake for 5 h. Fourteen infants were included in group C, 12 in group BM, and 12 in group F. There was no difference in energy intake or nitrogen balance at any time. On d 1, plasma enrichment for the nasogastric tracer was lower than for the intravenous tracer for all three groups, both for leucine and for alpha-keto-isocaproic acid. On d 7, the enrichment for leucine and alpha-keto-isocaproic acid for the nasogastric tracer was lower than for the intravenous tracer for the groups BM and F (BM: 3.65 +/- 1.20 nasogastric versus 4.64 +/- 0.64 i.v.; F: 4.37 +/- 1.14 nasogastric versus 5.21 +/- 0.9 i.v.). In the control group, there was no difference between tracers. The lower plasma enrichment for the nasogastric tracer compared with the intravenous tracer suggests uptake of leucine by the splanchnic tissues. We conclude that minimal enteral feeding--even in low volumes of 20 mL/kg/d--increases the leucine uptake by the splanchnic tissue. We speculate that this reflects a higher protein synthesis of splanchnic tissues in the groups receiving enteral nutrition.

Carbon Isotopes↗
PubMed2002

Research in children. A report of the Ethics Working Group of the CESP.

UNLABELLED: Research is essential for the improvement of care in patients, including children and incapacitated persons of whom children form a special group. Inclusion of an individual in research requires informed consent. As informed consent is impossible in children, they might be excluded from studies. Research in children, however, is needed to improve health care in this group. In this paper we discuss the pros and cons regarding research in children. CONCLUSION: research in children is acceptable if it is necessary to promote the health of the population represented and cannot be performed on legally competent persons instead.

Child↗