Admixture of a multivitamin preparation to parenteral nutrition: the major contributor to in vitro generation of peroxides

Feeding parenteral nutrition in the neonatal period programs dyslipidemia in adulthood in Yucatan miniature pigs

BACKGROUND

Early nutritional challenges can lead to permanent metabolic changes, increasing risk for developing chronic diseases later in life. Total parenteral nutrition (TPN) is a life-saving nutrition regimen, used especially in intrauterine growth-restricted (IUGR) neonates. Early TPN feeding alters metabolism, but whether these alterations are permanent is unclear. Programmed metabolism is likely caused by epigenetic changes due to imbalances of methyl nutrients.

OBJECTIVES

We sought to determine whether feeding TPN in early life would increase the risk of developing dyslipidemia in adulthood and whether supplementing the methyl nutrients betaine and creatine to TPN would prevent this development. We also sought to determine whether IUGR exacerbates the effects of neonatal TPN on lipid metabolism in adulthood.

METHODS

Female piglets (n=32, 7 d old) were used in four treatments: 24 normal weight piglets were randomized to sow-fed (SowFed), standard TPN (TPN-control), and TPN with betaine and creatine (TPN-B+C); 8 IUGR piglets were fed control TPN (TPN-IUGR) as a fourth group. After 2 weeks of treatment, all pigs were then fed a standard solid diet. At 8 mo old, central venous catheters were implanted to conduct postprandial fat tolerance tests.

RESULTS

Feeding TPN in the neonatal period led to dyslipidemia in adulthood, as indicated by higher postprandial triglyceride (TG) levels in TPN-control (P<0.05), compared to SowFed. IUGR piglets were particularly sensitive to neonatal TPN feeding, as TPN-IUGR piglets developed obesity and dyslipidemia in adulthood, as indicated by greater backfat thickness (P<0.05), higher liver TG (P<0.05), slower postprandial TG clearance (P<0.05), and elevated fasting plasma non-high density lipoprotein (HDL)-cholesterol (P<0.01), and non-esterified fatty acids (NEFA) (P<0.001), compared to TPN-control.

CONCLUSIONS

Feeding TPN in early life increases the risk of developing dyslipidemia in adulthood, especially in IUGR neonates; however, methyl nutrient supplementation to TPN did not prevent TPN-induced changes in lipid metabolism.

Early versus late parenteral nutrition in term and late preterm infants: a randomised controlled trial

BACKGROUND

There is limited evidence regarding the optimal time to commence parenteral nutrition (PN) in term and late preterm infants.

DESIGN

Single-centre, non-blinded, exploratory randomised controlled trial.

SETTING

A level-3 neonatal unit in a stand-alone paediatric hospital.

PATIENTS

Infants born ≥34 weeks of gestation and ≤28 days, who needed PN. Eligible infants were randomised on day 1 or day 2 of admission.

INTERVENTIONS

Early (day 1 or day 2 of admission, N=30) or late (day 6 of admission, N=30) PN.

MAIN OUTCOME MEASURES

Plasma phenylalanine and F2-isoprostane levels on day 4 and day 8 of admission. Secondary outcomes were amino-acid and fatty-acid profiles on day 4 and day 8, and clinical outcomes.

RESULTS

The postnatal age at randomisation was similar between the groups (2.3 (SD 0.8) vs 2.3 (0.7) days, p=0.90). On day 4, phenylalanine levels in early-PN infants were higher than in late-PN (mean (SD) 62.9 (26.7) vs 45.5 (15.3) µmol/L; baseline-adjusted percentage difference 25.8% (95% CI 11.6% to 39.9%), p<0.001). There was no significant difference in phenylalanine levels between the two groups on day 8. There was no significant difference between the groups for F2-isoprostane levels on day 4 (early-PN mean (SD) 389 (176) vs late-PN 419 (291) pg/mL; baseline-adjusted percentage difference: -4.4% (95% CI -21.5% to 12.8%) p=0.62) and day 8 (mean (SD) 305 (125) vs 354 (113) pg/mL; adjusted mean percentage difference -16.1 (95% CI -34.1 to 1.9) p=0.09).Postnatal growth restriction for weight was less severe in the early-PN group (change in weight z-score from baseline to discharge: -0.6 (0.6) vs -1.0 (0.6); p=0.02). The incidence of hyperglycaemia was greater in the early-PN group (20/30 (66.7%) vs 11/30 (36.7%), p=0.02).

CONCLUSIONS

The timing of the commencement of PN did not seem to affect the degree of oxidative stress in critically ill term and late preterm infants. The effect of transiently high plasma phenylalanine with early PN on clinical outcomes requires further investigation.

TRIAL REGISTRATION NUMBER

ACTRN12620000324910.

Parenteral Cysteine Supplementation in Preterm Infants: One Size Does Not Fit All

Due to their gastrointestinal immaturity or the severity of their pathology, many neonates require parenteral nutrition (PN). An amino acid (AA) solution is an important part of PN. Cysteine is a key AA for protein and taurine synthesis, as well as for glutathione synthesis, which is a cornerstone of antioxidant defenses. As cysteine could be synthesized from methionine, it is considered a nonessential AA. However, many studies suggest that cysteine is a conditionally essential AA in preterm infants due to limitations in their capacity for cysteine synthesis from methionine and the immaturity of their cellular cysteine uptake. This critical review discusses the endogenous synthesis of cysteine, its main biological functions and whether cysteine is a conditionally essential AA. The clinical evidence evaluating the effectiveness of the current methods of cysteine supplementation, between 1967 and 2023, is then reviewed. The current understanding of cysteine metabolism is applied to explain why these methods were not proven effective. To respond to the urgent need for changing the current methods of parenteral cysteine supplementation, glutathione addition to PN is presented as an innovative alternative with promising results in an animal model. At the end of this review, future directions for research in this field are proposed.

Dose-Response Effects of Glutathione Supplement in Parenteral Nutrition on Pulmonary Oxidative Stress and Alveolarization in Newborn Guinea Pig

In premature infants, glutathione deficiency impairs the capacity to detoxify the peroxides resulting from O₂ metabolism and those contaminating the parenteral nutrition (PN) leading to increased oxidative stress, which is a major contributor to bronchopulmonary dysplasia (BPD) development. In animals, the supplementation of PN with glutathione prevented the induction of pulmonary oxidative stress and hypoalveolarization (characteristic of BPD). Hypothesis: the dose of glutathione that corrects the plasma glutathione deficiency is sufficient to prevent oxidative stress and preserve pulmonary integrity. Three-day-old guinea pigs received a PN, supplemented or not with GSSG (up to 1300 µg/kg/d), the stable form of glutathione in PN. Animals with no handling other than being orally fed constituted the control group. After 4 days, lungs were removed to determine the GSH, GSSG, redox potential and the alveolarization index. Total plasma glutathione was quantified. The effective dose to improve pulmonary GSH and prevent the loss of alveoli was 330 µg/kg/d. A 750 µg/kg/d dose corrected the low-plasma glutathione, high-pulmonary GSSG and oxidized redox potential. Therefore, the results suggest that, in a clinical setting, the dose that improves low-plasma glutathione could be effective in preventing BPD development.

Light protection of parenteral nutrition, cholestasis, and other prematurity-related morbidities in premature infants

INTRODUCTION

Parenteral Nutrition (PN) can lead to intestinal failure associated liver disease (IFALD). There are no human studies to date studying specifically the benefits of light-protection on neonatal IFALD. Recently, the European Medicines Agency and the American Society for Parenteral and Enteral Nutrition (ASPEN) both recommended full light protection of PN to reduce the risk of adverse clinical outcomes.

OBJECTIVE

The primary objective of this study was to evaluate the impact of light-protecting PN on the incidence of cholestasis and peak direct bilirubin levels in premature infants.

STUDY DESIGN

Retrospective chart review of preterm infants requiring PN for a minimum of 2 weeks with or without light-protection. After light protection of the PN solution, primary outcomes (including cholestasis and direct bilirubin levels) of both groups were compared. Secondary outcomes include evaluation of bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), sepsis and mortality.

RESULTS

A total of 50 preterm infants <37 weeks gestation were included, 25 infants in each group. There was a statistically significant decrease in the rate of cholestasis (12 vs. 3, p = 0.005), median peak direct bilirubin levels (1.7 vs. 0.9 mg/dL, p = 0.02) and total bilirubin levels (4.1 vs. 3.4, p = 0.05) in the light-protection group compared to no light-protection group. There was a decrease in the incidence of severe BPD (with an increase of mild BPD, resulting in the same overall BPD rate) in the light-protection compared to no light-protection group (7 vs. 15, p = 0.0223). There was no difference in NEC, ROP, sepsis or mortality.

CONCLUSION

Our study supports that the practice of light-protecting PN may reduce the incidence of IFALD in premature infants. Moreover, there was a trend toward decreased incidence of severe BPD in the light-protection group. Further light protection studies are needed to confirm these findings.

Parenteral nutrition compatibility and stability: A comprehensive review

Several guidance documents support best practices across the stages of the parenteral nutrition (PN)-use process to optimize patient safety. The critical step of PN order verification and review by the pharmacist requires a contextual assessment of the compatibility and stability implications of the ordered PN prescription. This article will provide working definitions, describe PN component characteristics, and present a wide-ranging representation of compatibility and stability concerns that need to be considered prior to preparing a PN admixture. This paper has been approved by the ASPEN Board of Directors. This article is protected by copyright. All rights reserved.

Stability of glutathione added as a supplement to parenteral nutrition

BACKGROUND

Most very premature newborns (< 32 weeks of gestation) receive parenteral nutrition (PN) that is inherently contaminated with peroxides. Oxidative stress induced by PN is associated with bronchopulmonary dysplasia, a main pathological complication in these babies who have weak antioxidant capacity to detoxify peroxides because of their glutathione deficiency. In animals, glutathione supplementation of PN prevented oxidative stress and alveolar loss (the main characteristic of bronchopulmonary dysplasia). Of its two forms - disulfide (GSSG) and free thiol (GSH) - GSSG was used because of its better stability in PN. However, a 30% loss of GSSG in PN is observed. The potentially high therapeutic benefits of GSSG supplementation on the health of very premature babies makes the study of its stability highly important.

MATERIALS AND METHODS

GSSG was incubated in combination with the following components of PN: dextrose, multivitamins, Primene, Travasol, as well as with cysteine, cystine and peroxides for 24h. Total glutathione in these solutions was measured 0-24h after the addition of GSSG.

RESULTS

The combination of cysteine and multivitamins caused the maximum loss of glutathione. The stability of GSSG was not affected by multivitamins. The cysteine was responsible for about 20% of the loss of GSSG, in presence of multivitamins the loss reached more than 70%. Removing the cysteine prevented the degradation of glutathione.

CONCLUSION

GSSG reacts with cysteine to form cysteine-glutathione disulfide, another suitable glutathione substrate for preterm neonates. The study confirms that GSSG added to PN can potentially provide a precursor to de novo synthesis of glutathione in vivo. This article is protected by copyright. All rights reserved.

Recommendations for photoprotection of parenteral nutrition for premature infants: An ASPEN position paper

Although crucial in improving health outcomes in the preterm infants, parenteral nutrition (PN) is not without risk, especially if handled improperly. A growing body of evidence suggests that components of PN admixtures, including lipid injectable emulsions (ILEs), are susceptible to degradation, including oxidation when exposed to light (ie, photo-oxidation), resulting in the production of reactive oxygen species. Infants, especially those born preterm, are considered more susceptible to consequences of oxidative stress than children and adults. Oxidative stress is associated with bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, and intestinal failure-associated liver disease. The American Society for Parenteral and Enteral Nutrition (ASPEN) assembled a working group to provide recommendations on clinical practice surrounding photoprotection of PN.This Position Paper reviews the scientific literature on the formation of quantifiable peroxides and other degradation products when PN admixtures and ILEs are exposed to light and reports adverse clinical outcomes in premature infants exposed to PN. Recommendations for photoprotection of PN admixtures and ILEs are provided, as well as the challenges in achieving complete photoprotection with the equipment, supplies, and materials currently available in the US. ASPEN and the authors understand that the full implementation of complete photoprotection may not currently be feasible given current product availability; recommendations provided in this paper serve to represent the goal to which to strive as well as to highlight the importance of product availability to achieve these practices. This paper has been approved by the ASPEN Board of Directors.

Lichtschutz für Lösungen zur parenteralen Ernährung von Säuglingen und Kindern bis zum Alter von 2 Jahren

Das Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) empfahl im Rote-Hand-Brief vom 02.09.2019: „Während der Verabreichung an Neugeborene und Kinder unter 2 Jahren sollen entsprechend zugelassene Arzneimittel zur parenteralen Ernährung (PE), die Aminosäuren und/oder Fettemulsionen enthalten, vor Licht geschützt werden (Behältnisse und Infusionsbestecke)“.

Ziel dieser Stellungnahme ist es, evidenzbasierte Empfehlungen zum Lichtschutz für Lösungen zu parenteraler und heimparenteraler Ernährung bei Säuglingen und Kindern bis zum Alter von 2 Jahren zu geben.

Der Bundesverband Deutscher Krankenhausapotheker, die Ernährungskommission der Deutschen Gesellschaft für Kinder- und Jugendmedizin, die Ernährungskommission der Österreichischen Gesellschaft für Kinder und Jugendheilkunde und die Arbeitsgemeinschaft Chronisches Darmversagen der Gesellschaft für Pädiatrische Gastroenterologie und Ernährung empfehlen in Übereinstimmung mit den internationalen Empfehlungen zur pädiatrischen parenteralen Ernährung der Fachgesellschaften ESPGHAN, ESPEN, ESPR und CSPEN: 1. Parenterale Nährlösungen, die Fette und/oder Vitamine enthalten, sind während der Applikation durch geeignete Maßnahmen vor Licht zu schützen. 2. Parenterale Nährlösungen, die keine Fette und/oder Vitamine enthalten (z. B. Lösungen mit Aminosäuren, Glucose, Elektrolyten oder Spurenelementen) bedürfen keines speziellen Lichtschutzes. 3. Bei heimparenteraler Ernährung können im Hinblick auf die kindlichen Bedürfnisse normale Spiralleitungen verwendet werden, solange lichtschützende Spiralleitungen nicht verfügbar sind.

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

Neonatal Vitamin C and Cysteine Deficiencies Program Adult Hepatic Glutathione and Specific Activities of Glucokinase, Phosphofructokinase, and Acetyl-CoA Carboxylase in Guinea Pigs' Livers

Premature neonates are submitted to an early-life oxidative stress from parenteral nutrition, which is vitamin C (VC) deficient and induces low endogenous levels of glutathione. The oxidative stress caused by these deficiencies may permanently affect liver glycolysis and lipogenesis. This study evaluates the short- and long-term effects of neonatal VC and cysteine deficient diets on redox and energy metabolism. Three-day-old Hartley guinea pigs from both sexes were given a regular or a deficient diet (VC, cysteine, or both) until week 1 of life. Half of the animals were sacrificed at this age, while the other half ate a complete diet until 12 weeks. Liver glutathione and the activity and protein levels of glucokinase, phosphofructokinase, and acetyl-CoA-carboxylase were measured. Statistics: factorial ANOVA (5% threshold). At 1 week, all deficient diets decreased glutathione and the protein levels of glucokinase and phosphofructokinase, while cysteine deficiency decreased acetyl-CoA-carboxylase levels. A similar enzyme level was observed in control animals at 12 weeks. At this age, VC deficiency decreased glutathione, while cysteine increased it. Acetyl-CoA-carboxylase protein levels were increased, which decreased its specific activity. Early-life VC and cysteine deficiencies induce neonatal oxidative stress and an adult-like metabolism, while predisposing to increased lipogenic rates during adulthood.

Oxidative stress biomarkers in the preterm infant

Oxidative stress (OS) plays a key role in the pathophysiology of preterm infants. Accurate assessment of OS remains an analytical challenge that has been partially addressed during the last few decades. A plethora of approaches have been developed to assess preterm biofluids to demonstrate a link postnatally with preterm OS, giving rise to a set of widely employed biomarkers. However, the vast number of different analytic methods and lack of standardization hampers reliable comparison of OS-related biomarkers. In this chapter, we discuss approaches for the study of OS in prematurity with respect to methodologic considerations, the metabolic source of different biomarkers and their role in clinical studies.

Neonatal parenteral nutrition affects the metabolic flow of glucose in newborn and adult male Hartley guinea pigs' liver

Extremely premature birth is associated with a permanent disruption of energy metabolism. The underlying mechanisms are poorly understood. The oxidative stress induced by parenteral nutrition (PN) during the first week of life is suspected to reprogram energy metabolism in the liver. Full-term male Hartley guinea pigs (to isolate PN from prematurity) receiving PN enriched or not with glutathione (to isolate PN effects from PN-induced oxidative stress effects) or an Oral Nutrition (ON) during the first week of life were used. At 1 week (neonatal) and 16 weeks (adult), measurements of liver glutathione (GSH and GSSG) and activities of three key enzymes of energy metabolism (glucokinase (GCK), phosphofructokinase (PFK), and acetyl-CoA carboxylase (ACC)) were performed. Differences between groups were reported if p ≤ 0.05 (Analysis of Variance). At 1 week, compared to ON, PN induced higher GSSG (oxidative stress), higher GCK activity, and lower PFK and ACC activity, the glutathione supplement prevented all PN effects. At 16 weeks, early PN induced lower GSSG (reductive stress) and lower GCK activity, which was prevented by added glutathione, and higher ACC activity independent of glutathione supplement. ACC was negatively associated (r2 = 0.33) with GSSG. Increased nicotinamide adenine dinucleotide phosphate levels confirmed the glucose-6-phosphate accumulation at 1 week, whereas our protocol failed to document lipid accumulation at 16 weeks. In adult male guinea pigs, neonatal exposure to PN affected glutathione metabolism leading to reductive stress (lower GSSG) and an altered metabolic flow of glucose. Partial prevention with glutathione supplementation suggests that, in addition to peroxides, other factors of PN are involved.

Relationship between redox potential of glutathione and DNA methylation level in liver of newborn guinea pigs

The metabolism of DNA methylation is reported to be sensitive to oxidant molecules or oxidative stress. Hypothesis: early-life oxidative stress characterized by the redox potential of glutathione influences the DNA methylation level. The in vivo study aimed at the impact of modulating redox potential of glutathione on DNA methylation. Newborn guinea pigs received different nutritive modalities for 4 days: oral nutrition, parenteral nutrition including lipid emulsion Intralipid (PN-IL) or SMOFLipid (PN-SF), protected or not from ambient light. Livers were collected for biochemical determinations. Redox potential (p < 0.001) and DNA methylation (p < 0.01) were higher in PN-infused animals and even higher in PN-SF. Their positive correlation was significant (r² = 0.51; p < 0.001). Methylation activity was higher in PN groups (p < 0.01). Protein levels of DNA methyltransferase (DNMT)-1 were lower in PN groups (p < 0.01) while those of both DNMT3a isoforms were increased (p < 0.01) and significantly correlated with redox potential (r² > 0.42; p < 0.001). The ratio of SAM (substrate) to SAH (inhibitor) was positively correlated with the redox potential (r² = 0.36; p < 0.001). In conclusion, early in life, the redox potential value strongly influences the DNA methylation metabolism, resulting in an increase of DNA methylation as a function of increased oxidative stress. These results support the notion that early-life oxidative stress can reprogram the metabolism epigenetically. This study emphasizes once again the importance of improving the quality of parenteral nutrition solutions administered early in life, especially to newborn infants.

Abbreviation of Title: Parenteral nutrition and DNA methylation

Enteral and parenteral nutrition considerations in pediatric patients

PURPOSE

Current clinical practice guidelines on management of enteral nutrition (EN) and parenteral nutrition (PN) in pediatric patients are reviewed.

SUMMARY

The provision of EN and PN in pediatric patients poses many unique considerations and challenges. Although indications for use of EN and PN are similar in adult and pediatric populations, recommended EN and PN practices differ for pediatric versus adult patients in areas such as selection of EN and PN formulations, timing of EN and PN initiation, advancement of nutrition support, and EN and PN goals. Additionally, provision of EN and PN to pediatric patients poses unique compounding and medication administration challenges. This article provides a review of current EN and PN best practices and special nutrition considerations for neonates, infants, and other pediatric patients.

CONCLUSION

The provision of EN and PN to pediatric patients presents many unique challenges. It is important for pharmacists to keep current with pediatric- and neonatal-specific guidelines on nutritional management of various disease states, as well as strategies to address compounding and medication administration challenges, in order to optimize EN and PN outcomes.

Parenteral nutrition and oxidant stress in the newborn: A narrative review

There is strong evidence that oxidant molecules from various sources contaminate solutions of parenteral nutrition following interactions between the mixture of nutrients and some of the environmental conditions encountered in clinical practice. The continuous infusion of these organic and nonorganic peroxides provided us with a unique opportunity to study in cells, in vascular and animal models, the mechanisms involved in the deleterious reactions of oxidation in premature infants. Potential clinical impacts of peroxides infused with TPN include: a redox imbalance, vasoactive responses, thrombosis of intravenous catheters, TPN-related hepatobiliary complications, bronchopulmonary dysplasia and mortality. This is a narrative review of published data.

Glutathione Supplementation of Parenteral Nutrition Prevents Oxidative Stress and Sustains Protein Synthesis in Guinea Pig Model

Peroxides contaminating parenteral nutrition (PN) limit the use of methionine as a precursor of cysteine. Thus, PN causes a cysteine deficiency, characterized by low levels of glutathione, the main molecule used in peroxide detoxification, and limited growth in individuals receiving long-term PN compared to the average population. We hypothesize that glutathione supplementation in PN can be used as a pro-cysteine that improves glutathione levels and protein synthesis and reduces oxidative stress caused by PN. One-month-old guinea pigs (7–8 per group) were used to compare glutathione-enriched to a non-enriched PN, animals on enteral nutrition were used as a reference. PN: Dextrose, amino acids (Primene), lipid emulsion (Intralipid), multivitamins, electrolytes; five-day infusion. Glutathione (GSH, GSSG, redox potential) and the incorporation of radioactive leucine into the protein fraction (protein synthesis index) were measured in the blood, lungs, liver, and gastrocnemius muscle. Data were analysed by ANOVA; p < 0.05 was considered significant. The addition of glutathione to PN prevented the PN-induced oxidative stress in the lungs and muscles and supported protein synthesis in liver and muscles. The results potentially support the recommendation to add glutathione to the PN and demonstrate that glutathione could act as a biologically available cysteine precursor.

Sex-Specificity of Oxidative Stress in Newborns Leading to a Personalized Antioxidant Nutritive Strategy

Oxidative stress is a critical process that triggers several diseases observed in premature infants. Growing recognition of the detriment of oxidative stress in newborns warrants the use of an antioxidant strategy that is likely to be nutritional in order to restore redox homeostasis. It appears essential to have a personalized approach that will take into account the age of gestation at birth and the sex of the infant. However, the link between sex and oxidative stress remains unclear. The aim of this study was to find a common denominator explaining the discrepancy between studies related to sex-specific effects of oxidative stress. Results highlight a specificity of sex in the levels of oxidative stress markers linked to the metabolism of glutathione, as measured in the intracellular compartments. Levels of all sex-dependent oxidative stress markers are greater and markers associated to a better antioxidant defense are lower in boys compared to girls during the neonatal period. This sex-specific discrepancy is likely to be related to estrogen metabolism, which is more active in baby-girls and promotes the activation of glutathione metabolism. Conclusion: our observations suggest that nutritive antioxidant strategies need to target glutathione metabolism and, therefore, should be personalized considering, among others, the sex specificity.

Adult Consequences of Extremely Preterm Birth: Cardiovascular and Metabolic Diseases Risk Factors, Mechanisms, and Prevention Avenues

Extremely preterm babies are exposed to various sources of injury during critical stages of development. The extremely preterm infant faces premature transition to ex utero physiology and undergoes adaptive mechanisms that may be deleterious in the long term because of permanent alterations in organ structure and function. Perinatal events can also directly cause structural injury. These disturbances induce morphologic and functional changes in their organ systems that might heighten their risks for later adult chronic diseases. This review examines the pathophysiology of programming of long-term health and diseases after preterm birth and associated perinatal risk factors.

p38/p53/miR-200a-3p feedback loop promotes oxidative stress-mediated liver cell death

Although our previous studies have provided evidence that oxidative stress has an essential role in total parenteral nutrition (TPN)-associated liver injury, the mechanisms involved are incompletely understood. Here, we show the existence of crosstalk between the miR-200 family of microRNAs and oxidative stress. The members of the miR-200 family are markedly enhanced in hepatic cells by hydrogen peroxide (H2O2) treatment. The upregulation of miR-200-3p in turn modulates the H2O2-mediated oxidative stress response by targeting p38α. The enhanced expression of miR-200-3p mimics p38α deficiency and promotes H2O2-induced cell death. Members of the miR-200 family that are known to inhibit the epithelial to mesenchymal transition (EMT) are induced by the tumor suppressor p53. Here, we show that p53 phosphorylation at Ser 33 contributes to H2O2-induced miR-200s transcription. In addition, we show that p38α can directly phosphorylate p53 at serine 33 upon H2O2 exposure. Thus, we suggest that in liver cells, the oxidative stress-induced, p38α-mediated phosphorylation of p53 at Ser33 is essential for the functional regulation of oxidative stress-induced miR-200 transcription by p53. Collectively, our data indicate that the p53-dependent expression of miR-200a-3p promotes cell death by inhibiting a p38/p53/miR-200 feedback loop.

Impact of glutathione supplementation of parenteral nutrition on hepatic methionine adenosyltransferase activity

Background

The oxidation of the methionine adenosyltransferase (MAT) by the combined impact of peroxides contaminating parenteral nutrition (PN) and oxidized redox potential of glutathione is suspected to explain its inhibition observed in animals. A modification of MAT activity is suspected to be at origin of the PN-associated liver disease as observed in newborns. We hypothesized that the correction of redox potential of glutathione by adding glutathione in PN protects the MAT activity.

Aim

To investigate whether the addition of glutathione to PN can reverse the inhibition of MAT observed in animal on PN.

Methods

Three days old guinea pigs received through a jugular vein catheter 2 series of solutions. First with methionine supplement, (1) Sham (no infusion); (2) PN: amino acids, dextrose, lipids and vitamins; (3) PN-GSSG: PN+10 μM GSSG. Second without methionine, (4) D: dextrose; (5) D+180 μM ascorbylperoxide; (6) D+350 μM H₂O₂. Four days later, liver was sampled for determination of redox potential of glutathione and MAT activity in the presence or absence of 1 mM DTT. Data were compared by ANOVA, p<0.05.

Results

MAT activity was 45±4% lower in animal infused with PN and 23±7% with peroxides generated in PN. The inhibition by peroxides was associated with oxidized redox potential and was reversible by DTT. Correction of redox potential (PN+GSSG) or DTT was without effect on the inhibition of MAT by PN. The slope of the linear relation between MAT activity and redox potential was two fold lower in animal infused with PN than in others groups.

Conclusion

The present study suggests that prevention of peroxide generation in PN and/or correction of the redox potential by adding glutathione in PN are not sufficient, at least in newborn guinea pigs, to restore normal MAT activity.

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Methionine adenosyltransferase (MAT) is essential for healthy liver.

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Parenteral nutrition (PN) inhibits hepatic MAT.

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The inhibition is caused by intrinsic peroxides and by unknown component of PN.

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Adding glutathione in PN is not sufficient to prevent PN-associated liver diseases.

Adding glutathione to parenteral nutrition prevents alveolar loss in newborn Guinea pig

Bronchopulmonary dysplasia, a main complication of prematurity, is characterized by an alveolar hypoplasia. Oxidative stress is suspected to be a trigger event in this population who has a low level of glutathione, a main endogenous antioxidant, and who receives high oxidative load, particularly ascorbylperoxide from their parenteral nutrition.

HYPOTHESIS

the addition of glutathione (GSSG) in parenteral nutrition improves detoxification of ascorbylperoxide by glutathione peroxidase and therefore prevents exaggerated apoptosis and loss of alveoli.

METHODS

Ascorbylperoxide is assessed as substrate for glutathione peroxidase in Michaelis-Menten kinetics. Three-days old guinea pig pups were divided in 6 groups to receive, through a catheter in jugular vein, the following solutions: 1) Sham (no infusion); 2) PN(-L): parenteral nutrition protected against light (low ascorbylperoxide); 3) PN(+L): PN without photo-protection (high ascorbylperoxide); 4) 180 μM ascorbylperoxide; 5) PN(+L)+10 μM GSSG; 6) ascorbylperoxyde+10 μM GSSG. After 4 days, lungs were sampled and prepared for histology and biochemical determinations. Data were analysed by ANOVA, p < 0.05 RESULTS: The Km of ascorbylperoxide for glutathione peroxidase was 126 ± 6 μM and Vmax was 38.4 ± 2.5 nmol/min/ U. The presence of GSSG in intravenous solution has prevented the high GSSG, oxidized redox potential of glutathione, activation of caspase-3 (apoptosis marker) and loss of alveoli induced by PN(+L) or ascorbylperoxide.

CONCLUSION

A correction of the low glutathione levels observed in newborn animal on parenteral nutrition, protects lungs from toxic effect of ascorbylperoxide. Premature infants having a low level of glutathione, this finding is of high importance because it provides hope in a possible prevention of bronchopulmonary dysplasia.

Ascorbylperoxide from parenteral nutrition induces an increase of redox potential of glutathione and loss of alveoli in newborn guinea pig lungs

Background

Bronchopulmonary dysplasia is one of the main complications associated with extreme prematurity. Oxidative stress is suspected to be a trigger event of this lung disease, which is characterized by impaired alveolar development. Peroxides, mainly ascorbylperoxide and H₂O₂, are known contaminant of parenteral nutrition. We hypothesize that these oxidant molecules induce bronchopulmonary dysplasia development. The aim was to determine if the infusion of ascorbylperoxide, whether in presence or absence of H₂O₂, is associated with oxidative stress, apoptosis and loss of alveoli in the lungs of newborn guinea pigs.

Method

Three-day-old guinea pigs received parenteral solutions containing 0, 20, 60 or 180 µM ascorbylperoxide in the presence or not of 350 µM H₂O₂ (concentrations similar to those measured in parenteral nutrition). After 4 days, the lungs were collected for determination of glutathione's redox potential, caspase-3 activation (an apoptosis marker), alveolarization index (by histology), activation of Nrf2 and NF?B (biological markers of oxidative stress), and IL-6 and PGJ₂ levels (markers of NF?B activation). Groups were compared by ANOVA, p < 0.05.

Results

Loss of alveoli was associated with ascorbylperoxide in a dose-dependent manner, without an influence of H₂O₂. The dose-dependent activation of caspase-3 by ascorbylperoxide was lower in the presence of H₂O₂. Ascorbylperoxide induced an increase of redox potential in a dose-dependent manner, which reached a plateau in presence of H₂O₂. Nrf2 and NF?B were activated by H₂O₂ but not by ascorbylperoxide.

Conclusion

Results suggest that ascorbylperoxide, generated in parenteral nutrition, is involved in the development of bronchopulmonary dysplasia, independently of the increase of the redox potential. This study underlines the importance of developing a safer formulation of parenteral nutrition.

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Oxidative stress is suspected to induce bronchopulmonary dysplasia.

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We investigate the role of ascorbylperoxide contaminating parenteral nutrition.

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This molecule induces oxidation of redox potential, apoptosis and loss of alveoli.

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The alveolar loss is independent of the redox potential.

Total parenteral nutrition induces sustained hypomethylation of DNA in newborn guinea pigs

BACKGROUND

Neonatal total parenteral nutrition (TPN) is associated with animals with low glucose tolerance, body weight, and physical activity at adulthood. The early life origin of adult metabolic perturbations suggests a reprogramming of metabolism following epigenetic modifications induced by a change in the pattern of DNA expression. We hypothesized that peroxides contaminating TPN inhibit the activity of DNA methyltransferase (DNMT), leading to a modified DNA methylation state.

METHODS

Three groups of 3-d-old guinea pigs with catheters in their jugular veins were compared: (i) control: enterally fed with regular chow; (ii) TPN: fed exclusively with TPN (dextrose, amino acids, lipids, multivitamins, contaminated with 350 ± 29 μmol/l peroxides); (iii) H2O2: control + 350 μmol/l H2O2 intravenously. After 4 d, infusions were stopped and animals enterally fed. Half the animals were killed immediately after treatments and half were killed 8 wk later (n = 4-6 per group) for hepatic determination of DNMT activities and of 5'-methyl-2'-deoxycytidine (5MedCyd) levels, a marker of DNA methylation.

RESULTS

At 1 wk, DNMT and 5MedCyd were lower in the TPN and H2O2 groups as compared with controls. At 9 wk, DNMT remained lower in the TPN group, whereas 5MedCyd was lower in the TPN and H2O2 groups.

CONCLUSION

Administration of TPN or H2O2 early in life in guinea pigs induces a sustained hypomethylation of DNA following inhibition of DNMT activity.

Inhibition of hepatic methionine adenosyltransferase by peroxides contaminating parenteral nutrition leads to a lower level of glutathione in newborn Guinea pigs

Premature newborn infants on total parenteral nutrition (TPN) are at risk of oxidative stress because of peroxides contaminating TPN and low glutathione level. Low cysteine availability limits glutathione synthesis. In this population, the main source of cysteine derives from the hepatic conversion of methionine. The first enzyme of this conversion, methionine adenosyltransferase (MAT), contains redox-sensitive cysteinyl residues. We hypothesize that inhibition of MAT by peroxides contaminating TPN leads to a lower availability of cysteine for glutathione synthesis. At 3 days of life, animals were fitted with a jugular catheter for intravenous infusion. Four groups were compared by ANOVA (P<0.05): (1) Control, without surgery, fed regular chow; (2) Sham, fitted with an obstructed catheter, fed orally regular chow; (3) TPN, fed exclusively TPN (dextrose, amino acids, fat, vitamins) containing 350 μM peroxides; (4) H2O2, fed regular chow orally and infused with 350 μM H2O2. Four days later, MAT activity and glutathione in liver and blood were lower in TPN and H2O2 groups. The redox potential was more oxidized in blood and liver of the TPN group. In conclusion, peroxides generated in TPN inhibit methionine adenosyltransferase activity with, among consequences, a low level of glutathione and a more oxidized redox potential.

Prevention and treatment of intestinal failure-associated liver disease in children

Intestinal failure-associated liver disease (IFALD), a serious complication occurring in infants, children, and adults exposed to long-term parenteral nutrition (PN), causes a wide-spectrum of disease, ranging from cholestasis and steatosis to fibrosis and eventually cirrhosis. Known host risk factors for IFALD include low birth weight, prematurity, short bowel syndrome, and recurrent sepsis. The literature suggests that components of PN may also play a part of the multifactorial pathophysiology. Because some intravenous lipid emulsions (ILEs) may contribute to inflammation and interfere with bile excretion, treatment with ILE minimization and/or ILEs composed primarily of omega-3 fatty acids can be helpful, but requires careful monitoring for growth failure and essential fatty acid deficiency (EFAD). Data from randomized controlled trials are awaited to support widespread use of these approaches. Other IFALD treatments include cycling PN, ursodeoxycholic acid, sepsis prevention, photoprotection, and polyvinylchloride-free tubing. Management and prevention of IFALD remains a clinical challenge.

Influence of shielding TPN from photooxidation on the number of early blood transfusions in ELBW premature neonates

OBJECTIVES

The smallest premature neonates often receive blood transfusions early in life. Nonrestrictive transfusion policies are linked to deleterious outcomes. Exposure of total parenteral nutrition (TPN) to ambient light generates oxidation products associated with haemolysis in vitro. Shielding TPN from light limits oxidation. Our hypothesis was protecting TPN from light decreases haemolysis and therefore the need for early blood transfusions.

METHODS

Comparison of haemolysis between animals fed enterally and those receiving TPN, and exploratory case-control retrospective analysis of transfusion counts in premature infants receiving light-exposed or light-protected TPN. The statistical analysis was analysis of variance and longitudinal binomial regression model adjusting for potential covariables of transfusion counts.

RESULTS

In animals, TPN is associated with higher (P<0.05) haemolysis compared with enteral feeds; photoprotection induces lower peroxide load with no effect on the level of haemolysis. In premature infants, light-exposed (n=76) or light-protected (n=57) populations exhibited similar clinical characteristics. Initial haematocrit, gestational age, and index of disease severity had a significant effect on the number of transfusions. When adjusting for these covariables, photoprotection was no longer significant.

CONCLUSIONS

Even though peroxides are associated in vitro with haemolysis, shielding TPN from light to reduce infused peroxides does not significantly decrease the need for early transfusions in premature infants.

Hexapeptides from human milk prevent the induction of oxidative stress from parenteral nutrition in the newborn guinea pig

INTRODUCTION

In preterm neonates, peroxides contaminating total parenteral nutrition (TPN) contribute to oxidative stress, which is suspected to be a strong inducer of hepatic complications related to prematurity. Recently, others reported that hexapeptides derived from human milk (HM) exerted free radical-scavenging activities in vitro. Therefore, the aim of this study was to assess the capacity of these hexapeptides to limit the generation of peroxides in TPN and to prevent TPN-induced hepatic oxidative stress.

METHODS

At 3 d of life, guinea pigs were infused, through a catheter in jugular vein, with TPN containing or not peptide-A (YGYTGA) or peptide-B (ISELGW). Peroxide concentrations were measured in TPN solutions, whereas glutathione, glutathionyl-1,4-dihydroxynonenal (GS-HNE) and mRNA levels of interleukin-1 (IL-1) and tumor necrosis factor-α (TNFα) were determined in liver after 4 d of infusion.

RESULTS

The addition of peptide-A to TPN allowed a reduction in peroxide contamination by half. In vivo, peptide-A or peptide-B corrected the hepatic oxidative status induced by TPN. Indeed, both peptides lowered the hepatic redox potential of glutathione and the level of GS-HNE, a marker of lipid peroxidation. As compared with animals infused with TPN without peptide, the hepatic mRNA levels of IL-1 and TNFα were lower in animals infused with TPN containing peptide-A or peptide-B.

DISCUSSION

These results suggest that the addition of YGYTGA or ISELGW to TPN will reduce oxidative stress in newborns. The reduction in mRNA of two proinflammatory cytokines could be important for the incidence of hepatic complications related to TPN.

The mode of administration of total parenteral nutrition and nature of lipid content influence the generation of peroxides and aldehydes

BACKGROUND & AIMS

The absence of light protection of neonatal total parenteral nutrition (PN) contributes to the generation of 4-hydroxynonenal and peroxides. 4-Hydroxynonenal is suspected to be involved in PN-related liver complications.

AIMS

To find a practical modality to reduce 4-hydroxynonenal in PN and assess in vivo the impact of PN containing low 4-hydroxynonenal concentration.

METHODS

Six modalities of delivering PN were compared for the in vitro generation of peroxides and 4-hydroxynonenal: 1) MV-AA-L: light-protected (-L) solution containing multivitamin (MV) mixed with amino acids + dextrose (AA); 2) MV-AA+L: MV-AA without photo-protection (+L); 3) MV-LIP+L: MV mixed with lipid emulsion (LIP). LIP was a) Intralipid20%(®) or b) Omegaven(®). Hepatic markers of oxidative stress (glutathione, F(2α)-isoprostanes, GS-HNE) and inflammation (mRNA of TNF-α and IL-1) were measured in newborn guinea pigs infused during 4-days with MV-AA+L compounded with Intralipid20%(®) or Omegaven(®).

RESULTS

Hydroperoxides and 4-hydroxynonenal were the lowest in MV-AA-L and the highest in MV-LIP+L. MV-AA+L with Omegaven(®) was associated with the lowest levels of markers of oxidative stress and inflammation.

CONCLUSION

Compared to Intralipid20%(®), Omegaven(®) reduces oxidative stress associated with PN and prevents liver inflammation. These findings offer an alternative strategy to light protection of PN, which in the clinical setting is a cumbersome modality.

Inflammatory response in preterm infants is induced early in life by oxygen and modulated by total parenteral nutrition

The i.v. lipid emulsion (LIP) is a source of oxidants, which may stimulate inflammation. Coadministration of parenteral multivitamins (MVP) with LIP prevents lipid peroxidation in light-exposed total parenteral nutrition (TPN). We hypothesized that this modality of TPN administration affects systemic inflammation, which may be modulated by exposure to oxygen. Premature infants were allocated to three TPN regimens: control regimen - MVP coadministered with amino acid/dextrose exposed to ambient light, LIP provided separately (n = 9) - LIP+MVP light exposed (LE): MVP coadministered with light-exposed LIP (n = 9) - LIP+MVP light protected (LP): MVP coadministered with light-protected LIP (n = 8). In LE and LP, amino acid/dextrose was provided separately. On reaching full TPN, infants were sampled for IL-6 and IL-8 in plasma and the redox potential of glutathione in whole blood (E, mV). Data were compared (ANOVA) in infants exposed to low (<0.25) versus high (> or =0.25) FiO2. Patients (mean +/- SD: birth weight 797 +/- 172 g; GA 26 +/- 1 wk) had similar clinical characteristics in TPN groups. Cytokine levels correlated positively (p < 0.01) with FiO2 and E. High FiO2 stimulated an increase (p < 0.01) in cytokines in control regimen, whereas these markers remained unaffected by oxygen in the LE and LP groups. The choice of a TPN admixture may have important consequences on the systemic inflammatory response triggered by an oxidant stress.

Neonatal exposure to oxidants induces later in life a metabolic response associated to a phenotype of energy deficiency in an animal model of total parenteral nutrition

Failure to protect total parenteral nutrition (TPN) from ambient light exacerbates the generation of peroxides, which affects blood glucose and plasma triacylglyceride (TG) in neonates. Based on the concept that the origin of adult diseases can be traced back to perinatal life, it was hypothesized that neonatal exposure to peroxides may affect energy availability later in life. Three-day-old guinea pigs, fitted with a jugular catheter, were fed regular chow (sham) +/- i.v. 350 microM H2O2 (sham + H2O2) or nourished with light-protected TPN [TPN(-)L, 209 +/- 9 microM peroxides] or light-exposed TPN [TPN(+)L, 365 +/- 15 microM peroxides]. After 4 d, infusions were stopped and animals fed chow. Spontaneous ambulatory movements, fasting blood glucose, glucose tolerance, TG, hepatic activities of glucokinase, phosphofructokinase (key enzymes of glycolysis), and acetyl-CoA carboxylase (key enzymes of lipogenesis) were determined at 12-14 wk and compared by ANOVA (p < 0.05). Relative to sham, the animals from sham + H2O2, TPN(-)L and TPN(+)L groups had lower plasma TG explained for 36% by low phosphofructokinase activity; they had lower glucose tolerance, lower body weight, and lower physical activity. In conclusion, neonatal exposure to oxidant molecules such as peroxides has important consequences later in life on lipid and glucose metabolism leading to a phenotype of energy deficiency.

Ascorbylperoxide contaminating parenteral nutrition perturbs the lipid metabolism in newborn guinea pig

The light exposure of parenteral nutritive solutions generates peroxides such as H(2)O(2) and ascorbylperoxide [2,3-diketo-4-hydoxyperoxyl-5,6-dihydroxyhexanoic acid]. This absence of photoprotection is associated with higher plasma triacylglycerol (TG) concentration in premature infants and oxidative stress and H(2)O(2)-independent hepatic steatosis in animals. We hypothesized that ascorbylperoxide is the active agent leading to high TG. The aim was to investigate the role of ascorbylperoxide in glucose and lipid metabolism in an animal model of neonatal parenteral nutrition. Three-day-old guinea pigs received through a catheter in the jugular solutions containing dextrose plus 0, 90, 225, or 450 microM ascorbylperoxide. After 4 days, blood and liver were sampled and treated for determinations of TG, cholesterol, markers of oxidative stress (redox potential of glutathione and F(2alpha)-isoprostane), and activities and protein levels of acetyl-CoA carboxylase (ACC), glucokinase, and phosphofructokinase (PFK). Ascorbylperoxide concentration was measured in urine on the last day. Data were compared by analysis of variance (p < 0.05). Plasma TG and cholesterol and hepatic PFK activity increased (200% of control), whereas ACC activity decreased (66% of control) in the function of the amount of ascorbylperoxide infused. Both markers of oxidative stress were higher in animals receiving the highest amounts of ascorbylperoxide. The logarithmic relations between urinary ascorbylperoxide and plasma TG (r(2) = 0.69) and hepatic PFK activity (r(2) = 0.26) were positive, whereas they were negative with ACC activity (r(2) = 0.50). In conclusion, ascorbylperoxide contaminating parenteral nutrition stimulates glycolysis, allowing higher availability of substrates for lipid synthesis. The logarithmic relation between urinary ascorbylperoxide and plasma TG suggests a very low efficient concentration.

Innovative parenteral and enteral nutrition therapy for intestinal failure

Children with intestinal failure (IF) suffer from insufficient intestinal length or function, making them dependent on parenteral nutrition (PN) for growth and survival. PN and its components are associated with many complications ranging from simple electrolyte abnormalities to life-threatening PN-associated liver disease, which is also called intestinal failure-associated liver disease (IFALD). From a nutrition perspective, the ultimate goal is to provide adequate caloric requirements and make the transition from PN to full enteral nutrition (EN) successful. Upon review of the literature, we have summarized the most effective and innovative PN and EN therapies for this patient population. Antibiotic-coated catheters and antibiotic or ethanol locks can be implemented, as they appear effective in reducing catheter-related infection and thus further reduce the risk of IFALD. Lipid emulsions should be given judiciously. The use of an omega-3 fatty acid-based formulation should be considered in patients who develop IFALD. Trophic feeding is important for intestinal adaptation, and EN should be initiated early to help wean patients from PN. Long-term management of children with IF continues to be an emerging field. We have entered uncharted territory as more children survive complications of IF and IFALD. Careful monitoring and individualized management to ensure maintenance of growth while avoiding complications are the keys to successful patient outcomes.

Early life events, sex, and arterial blood pressure in critically ill infants

OBJECTIVE

To determine whether photo-protecting total parenteral nutrition in preterm infants influences arterial blood pressure differently according to gender. Blood pressure is influenced by complex mechanisms of vasomodulation. Oxidants are mediators and effectors in such reactions. Shielding total parenteral nutrition from light contributes to decrease the generation of peroxides. Girls may be better protected against an oxidant load than boys. We questioned whether shielding total parenteral nutrition may have cardiovascular effects that are influenced by gender.

DESIGN

A post hoc subgroup analysis of the effect of shielding parenteral nutrition from light.

SETTING

Neonatal intensive care unit.

SUBJECTS

Preterm infants <1000 g with indwelling arterial catheters who received light exposed (n = 20) or light protected (n = 20) parenteral nutrition.

INTERVENTIONS

Invasive monitoring, total parenteral nutrition.

MEASUREMENTS AND MAIN RESULTS

Arterial blood pressure was recorded hourly and compared between light exposed and light protected over the first week of life; timed average maximum velocity (m/s) was measured in the superior mesenteric artery by Doppler; presence of ductus arteriosus was documented by cardiac ultrasound. Data were analyzed by analysis of variance. No differences were noted between light exposed and light protected in clinical determinants that may influence blood pressure. There was an interaction (p < .01) between gender and total parenteral nutrition on blood pressure. In girls (n = 17), systolic and diastolic blood pressures were higher (p < .01) and heart rate lower (p < .01) during light exposed. There was no effect on BP observed in boys (n = 23). The linear correlation between timed average maximum velocity and systolic blood pressure was positive (p < .05). There was no echocardographic difference in hemodynamic variables between boys (n = 21) and girls (n = 9) who had a patent ductus.

CONCLUSION

Failure to shield total parenteral nutrition from light results in higher blood pressure in a selected population of critically ill female infants. This information adds to our understanding of the multiple determinants involved in optimizing arterial blood pressure in a critical care environment.

Influence of the calcium concentration in the presence of organic phosphorus on the physicochemical compatibility and stability of all-in-one admixtures for neonatal use

BACKGROUND

Preterm infants need high amounts of calcium and phosphorus for bone mineralization, which is difficult to obtain with parenteral feeding due to the low solubility of these salts. The objective of this study was to evaluate the physicochemical compatibility of high concentrations of calcium associated with organic phosphate and its influence on the stability of AIO admixtures for neonatal use.

METHODS

Three TPN admixture formulas were prepared in multilayered bags. The calcium content of the admixtures was adjusted to 0, 46.5 or 93 mg/100 ml in the presence of a fixed organic phosphate concentration as well as lipids, amino acids, inorganic salts, glucose, vitamins and oligoelements at pH 5.5. Each admixture was stored at 4 degrees C, 25 degrees C or 37 degrees C and evaluated over a period of 7 days. The physicochemical stability parameters evaluated were visual aspect, pH, sterility, osmolality, peroxide formation, precipitation, and the size of lipid globules.

RESULTS

Color alterations occurred from the first day on, and reversible lipid film formation from the third day of study for the admixtures stored at 25 degrees C and 37 degrees C. According to the parameters evaluated, the admixtures were stable at 4 degrees C; and none of them presented precipitated particles due to calcium/phosphate incompatibility or lipid globules larger than 5 mum, which is the main parameter currently used to evaluate lipid emulsion stability. The admixtures maintained low peroxide levels and osmolarity was appropriate for parenteral administration.

CONCLUSION

The total calcium and calcium/phosphorus ratios studied appeared not to influence the physicochemical compatibility and stability of AIO admixtures.

Long-term impact of an antioxidant-deficient neonatal diet on lipid and glucose metabolism

Newborn infants are at risk for oxidative stress leading to metabolic syndrome features. Oxidative stress can be induced by oxidant load such as oxygen supplementation, peroxides from intravenous nutrition, or low antioxidant defenses. We hypothesize that a modulation of antioxidant defenses during the neonatal period, without external oxidant challenge, will have a long-term influence on energy metabolism. Guinea pigs were fed between their third and their seventh day of life a regular chow leading to "mature" antioxidant defenses or a deficient chow leading to lower antioxidant defenses. Between weeks 1 and 14, the animals were fed regular chow. The hepatic oxidized redox status of glutathione associated with the deficient diet (-221 +/- 2 vs -228 +/- 1 mV, p < 0.01) was maintained until 14 weeks. At 13-14 weeks, animals fed the deficient diet presented lower plasma TG (479 +/- 57 vs 853 +/- 32 microM, p < 0.01), lower blood glucose (5.8 +/- 0.3 vs 6.9 +/- 0.3 mM, p < 0.05), and better tolerance to glucose (p < 0.05). Blood glucose correlated negatively with the redox status (r2 = 0.47, p < 0.01). Low antioxidant defenses during the neonatal period induce a better energy substrate profile associated with an oxidized redox status later in life. These findings suggest being aware of negative consequences when adopting "aggressive" antioxidant therapies in newborn infants.

Effects of light exposure on total parenteral nutrition and its implications in the neonatal population

Total parenteral nutrition (TPN) is a necessary form of nutrition in neonates with functional or anatomical disruption of the digestive tract. However, laboratory and human investigation have shown that exposure of the TPN solution to light causes the formation of peroxides and other degradation products that are quantifiable in experimental TPN solutions, laboratory animals, and neonates. Premature neonates are at a higher risk for the development and progression of peroxide damage due to their relative lack of antioxidant and free radical scavenger reserves. Furthermore, cell damage seen in a number of neonatal disease states is exacerbated by the presence of peroxides that are generated via intrinsic pathologic processes and from exogenous sources such as TPN. Numerous studies show that the formation of TPN photodegradation products can be slowed or prevented by the application of various light protection mechanisms. While it is not yet known if minimizing TPN associated photodegradation byproducts has a significant direct effect on preventing or mitigating the overall clinical course of some neonatal disease states, it is becoming increasingly clear that light protecting TPN can avoid specific metabolic complications in neonatal patients. It is prudent to implement mechanisms that prevent photodegradation of TPN components from the manufacturer source to the point of patient administration.

Shielding parenteral nutrition from light: does the available evidence support a randomized, controlled trial?

BACKGROUND

Exposure of total parenteral nutrition to ambient light induces the generation of peroxides, creating oxidant stress, which potentially compounds complications of prematurity. Photograph protection of total parenteral nutrition reduces the peroxide load and has been shown to be associated with nutritional and biochemical benefits in animals and humans. It is unclear whether this reduction in peroxides from total parenteral nutrition leads to a reduction in the complications of prematurity, such as bronchopulmonary dysplasia. Our hypothesis was that shielding total parenteral nutrition from ambient light is linked to clinical benefits.

OBJECTIVE

The purpose of this work was to determine whether photograph protection of total parenteral nutrition (light protected), as compared with no photoprotection (light exposed), reduces the occurrence of bronchopulmonary dysplasia or death in preterm infants.

METHODS

The Canadian Neonatal Network provided data for infants born in 2006 at <28 weeks' gestation admitted to level 3 NICUs in Canada. A retrospective analysis was performed comparing bronchopulmonary dysplasia and death in infants who received light-exposed or light-protected parenteral nutrition. Data were analyzed by using logistic regression models. RESULTS. Thirteen NICUs offered partial light-protected (total parenteral nutrition bag only, intravenous tubing exposed) and 13 offered light-exposed parenteral nutrition; not a single NICU offered complete light-protected parenteral nutrition (total parenteral nutrition bag plus intravenous tubing). The incidence of bronchopulmonary dysplasia or death was 66% with light-protected (n = 428) vs 59% with light-exposed (n = 438) parenteral nutrition.

CONCLUSIONS

Partial photograph protection of total parenteral nutrition was not associated with a reduction in bronchopulmonary dysplasia or death as compared with no photograph protection; this relationship is confounded by covariates with strong associations with bronchopulmonary dysplasia. Partial photograph protection of total parenteral nutrition solutions confers no clinical benefit, while consuming valuable resources. A randomized, controlled trial is justified to determine whether there is a true "cause-and-effect" relationship between complete photoprotection of total parenteral nutrition and bronchopulmonary dysplasia or death.

A randomized controlled trial on parenteral nutrition, oxidative stress, and chronic lung diseases in preterm infants

OBJECTIVES

To evaluate the effect of trace elements (TEs), when added to total parenteral nutrition (TPN) solutions, on peroxides load, and to test the hypothesis that protection of TPN from light can decrease peroxides load and is associated with improvement in oxidant-related clinical outcomes in preterm infants.

SUBJECTS AND METHODS

A total of 80 preterm infants were randomized to 1 of 4 groups (n=20 each): group 1 received a mixture of dextrose and amino acids; group 2 received a mixture of dextrose, amino acids, and lipid emulsion; group 3 received dextrose, amino acids, lipid emulsion, and multivitamins (MVP); and group 4 received dextrose, amino acids, lipid emulsion, MVP, and TEs. Each group was subdivided into photo-protected and photo-exposed subgroups (n=10 each). Using ferrous oxidation of xylenol orange technique, we measured the baseline level of excreted urinary peroxides before and 48 hours after starting TPN. We examined the association among light protection, urinary peroxides, and clinical outcomes of these infants.

RESULTS

Baseline urinary peroxides ranged between 5.5 and 24.8 micromol/L. A significant increase in urinary peroxides was observed in all groups after receiving TPN. The use of TEs did not affect peroxide production. In regression analysis, the addition of MVP (P<0.0001) and the exposure to light (P=0.02) were significantly associated with increased urinary peroxides. In the overall population, light exposure was associated with a significant increase in the incidence of chronic lung disease (adjusted OR 9.26, confidence interval 1.2-73; P=0.03) but had no effect on mortality, necrotizing enterocolitis, or sepsis.

CONCLUSIONS

TEs in TPN solutions have no effect on the production of urinary peroxides. Addition of MVP and exposure of TPN to light are the 2 major sources of peroxides in TPN. Protection from ambient light is associated with a decrease in chronic lung disease.

Highlight Commentary on "Influence of lung oxidant and antioxidant status on alveolarization: Role of light-exposed total parenteral nutrition"

Bronchopulmonary dysplasia (BPD) is a frequent complication of premature newborns, particularly very low birth-weight babies (<1500 g). Undoubtedly multiple mechanisms contribute to the adverse outcomes associated with BPD but oxidative stress is one causative factor. In this issue of Free Radical Biology and Medicine, Lavoie et al. describe the increased peroxide generation when the multivitamin solution used for nutritional support, total parenteral nutrition (TPN), is exposed to ambient light. Because the premature newborn has limited antioxidant capacity, this increased oxidative burden from the TPN becomes increasingly significant. Infusion of this light-exposed solution in a newborn guinea pig decreased lung tissue vitamin C but not vitamin E. When the multivitamin and lipid solutions were mixed and then exposed to light, alveolarization of the developing lung was decreased. This study by Lavoie et al. highlights simple measures that can potentially decrease the oxidant burden delivered to this vulnerable population and improve alveolarization.

Variations in metabolic response to TPN are influenced more by sex than by light exposure

BACKGROUND

Failure to protect total parenteral nutrition (TPN) solutions from ambient light induces the generation of peroxides, which contributes to the oxidation of several amino acids. We hypothesized that photo-protection improves the metabolic response to TPN.

AIM

To study the effects of photo-protecting TPN on urinary nitrogen and vitamin C excretion and to evaluate in premature infants the influence of sex.

PATIENTS AND METHODS

Premature infants were randomized to receive from birth light-exposed (LE) or light-protected (LP) TPN. Upon reaching full TPN, parenteral nutrient intakes were correlated with normalized urinary nitrogen and vitamin C concentrations.

RESULTS

No differences were observed between LE and LP. However, sex-related differences were observed in nitrogen and vitamin C handling. In boys, 50% of the nitrogen loss was explained by parenteral amino acid intake, whereas in girls, no correlation was found. The inverse correlation observed between intake and urinary excretion only in girls suggests a state of greater vitamin C utilization in girls.

CONCLUSIONS

These results demonstrate that sex-related differences in nitrogen/protein metabolism reported during enteral nutrition are seen during TPN as well. Sex is an important variable that will need to be taken into account in future studies evaluating the potential clinical effects of photo-protecting TPN.

Shielding parenteral multivitamins from light increases vitamin A and E concentration in lung of newborn guinea pigs

BACKGROUND & AIMS

Exposure of parenteral multivitamin preparation (MVP) to light generates peroxides. Light-exposed MVP induces an oxidant stress in lung but not in liver. This discrepancy suggests differences in handling of infused antioxidant vitamins between the two organs.

HYPOTHESIS

antioxidant capacity of lung depends on the MVP concentration and light protection of infused solutions.

METHODS

Protocol 1: four groups of three-day old guinea pigs received the base solution (5% dextrose + 0.45% NaCl) enriched with 0%, 1%, 2% and 3% MVP. Protocol 2: three further groups received the base solution + 2% MVP either light-exposed or light-protected or light-protected + 300 microM H2O2. After 4 days, lung and liver were sampled for vitamin determinations. Data were analyzed by ANOVA.

RESULTS

In lung, vitamins A-C-E reached a plateau with 1% MVP. In liver, vitamin A and E increased according to their concentration in solutions. Light exposure and added-H2O2 were associated with lower vitamin E in lung and liver. Retinol was higher in lung and lower in liver of animals receiving light-protected compared to light-exposed solutions.

CONCLUSIONS

Light protection of 1% MVP is a better way to improve the pulmonary oxidant-antioxidant balance than to increase MVP (>1%) in parenteral nutrition.

Avaliação da eficiência da nutrição parenteral quanto à oferta de energia em pacientes oncológicos pediátricos

OBJETIVO: Avaliar a eficiência da nutrição parenteral administrada a pacientes oncológicos pediátricos quanto à oferta de energia, indicações e principais dificuldades no procedimento. MÉTODOS: Estudo observacional descritivo, realizado entre julho de 2003 e julho de 2004 no Instituto de Oncologia Pediátrica da Universidade Federal de São Paulo. Critérios de inclusão: pacientes com câncer recebendo nutrição parenteral nas unidades de internação. A análise da adequação energética foi efetuada usando-se equações preditivas para o cálculo do gasto energético basal ajustado para a progressão inicial. RESULTADOS: Foram 41 episódios de nutrição parenteral de, 1.016, internações (4%): 54% do sexo masculino, com mediana de uso de 10 dias (1-51). Demonstrou-se que em 56% dos episódios não se atingiu o gasto energético basal ajustado; 26% ficaram entre 100% e 120% e 18% acima de 120%. A média do gasto energético basal ajustado foi 106%, com desvio-padrão de 38% e a mediana 96%. Os motivos associados às dificuldades para atingir o gasto energético basal foram intolerância metabólica, via de nutrição parenteral não exclusiva, suspensão ou interrupção da sua administração, prescrição sem discussão com nutricionista e uso de via periférica. A principal indicação foi por toxicidade gastrintestinal. O volume desprezado de nutrição parenteral demonstrou-se superior a 10% em 17 de 35 episódios (49%). Proteção contra luz ambiente (capa), avaliada em 19 pacientes durante os dias da administração, detectou ausência em 37 de 315 dias (12%). CONCLUSÃO: A oferta de energia não contemplou as necessidades de alta porcentagem de pacientes, principalmente devido à gravidade do quadro clínico, às interrupções e ao uso de via não exclusiva, reduzindo o período disponível para administração da nutrição. A eficiência dos procedimentos por atuação de equipe multidisciplinar poderia reduzir o prejuízo, garantindo uma oferta mais adequada, aumentando os benefícios da nutrição parenteral.