Effects of enterally administering granulocyte colony-stimulating factor to suckling mice

Evolutionary bridges: how factors present in amniotic fluid and human milk help mature the gut

Necrotizing enterocolitis (NEC) continues to be a leading cause of morbidity and mortality in preterm infants. As modern medicine significantly improves the survival of extremely premature infants, the persistence of NEC underscores our limited understanding of its pathogenesis. Due to early delivery, a preterm infant's exposure to amniotic fluid (AF) is abruptly truncated. Replete with bioactive molecules, AF plays an important role in fetal intestinal maturation and preparation for contact with the environment, thus its absence during development of the intestine may contribute to increased susceptibility to NEC. Human milk (HM), particularly during the initial phases of lactation, is a cornerstone of neonatal intestinal defense. The concentrations and activities of several bioactive factors in HM parallel those of AF, suggesting continuity of protection. In this review, we discuss the predominant overlapping bioactive components of HM and AF, with an emphasis on those associated with intestinal growth or reduction of NEC.

Human Milk Growth Factors and Their Role in NEC Prevention: A Narrative Review

Growing evidence demonstrates human milk's protective effect against necrotizing enterocolitis (NEC). Human milk derives these properties from biologically active compounds that influence intestinal growth, barrier function, microvascular development, and immunological maturation. Among these protective compounds are growth factors that are secreted into milk with relatively high concentrations during the early postnatal period, when newborns are most susceptible to NEC. This paper reviews the current knowledge on human milk growth factors and their mechanisms of action relevant to NEC prevention. It will also discuss the stability of these growth factors with human milk pasteurization and their potential for use as supplements to infant formulas with the goal of preventing NEC.

Immunomodulatory Effects of Human Colostrum and Milk

The immune system is not fully developed in human neonates and infants; breastfeeding is important in this stage as the bioactive components of human breast milk are known to have anti-microbial, anti-inflammatory, and immunomodulatory effects, and can therefore contribute to an infant's immunity against allergies, asthma, autoimmune diseases, and inflammatory bowel disease. Herein, the positive effect on the immune system by human colostrum and milk are reviewed.

Medicinal Uses of Hematopoietic Growth Factors in Neonatal Medicine

This review focuses on certain hematopoietic growth factors that are used as medications in clinical neonatology. It is important to note at the chapter onset that although all of the pharmacological agents mentioned in this review have been approved by the US Food and Drug administration for use in humans, none have been granted a specific FDA indication for neonates. Thus, in a sense, all of the agents mentioned in this chapter could be considered experimental, when used in neonates. However, a great many of the pharmacological agents utilized routinely in neonatology practice do not have a specific FDA indication for this population of patients. Consequently, many of the agents reviewed in this chapter are considered by some practitioners to be nonexperimental and are used when they judge such use to be "best practice" for the disorders under treatment.The medicinal uses of the agents in this chapter vary considerably, between geographic locations, and sometimes even within an institutions. "Consistent approaches" aimed at using these agents in uniform ways in the practice of neonatology are encouraged. Indeed some healthcare systems, and some individual NICUs, have developed written guidelines for using these agents within the practice group. Some such guidelines are provided in this review. It should be noted that these guidelines, or "consistent approaches," must be viewed as dynamic and changing, requiring adjustment and refinement as additional evidence accrues.

Recent Advances in Neonatal Pharmacotherapy

Objective:

To provide commentary and reviews and brief discussions in controversial or innovative recent advances in neonatal pharmacotherapy. To discuss cutting edge drug delivery systems that may become useful in neonatal drug delivery in the future.

Data Sources:

Articles were identified through searches of MEDLINE (1990–October 2005), key articles in the authors' files, and in some cases, through data generated and/or published by the author of a particular topic.

Data Selection:

Article selection and relevance to the topics under discussion was determined by individual authors.

Data Synthesis:

Therapeutic strategies addressed in this review include the use of hematopoietic growth factors including a simulated amniotic fluid preparation containing these growth factors for neonates with selected gastrointestinal problems, erythropoietin for neuroprotection following perinatal asphyxia, drug therapy advances in treatment of patent ductus arteriosus (PDA), evaluation of advances in transdermal drug delivery, and its potential application to neonates and advances in the treatment of persistent pulmonary hypertension (PPHN) of the newborn.

Conclusions:

Despite being over 30 years old, the practice of neonatology is as much of an art as a science. Advances in the basic science research have improved our understanding of use of pharmacologic agents in the premature and full-term neonate including drug disposition pathways. Expanding our knowledge on issues such as physiology of hematopoietic factors, the pharmacologic responses of conditions such as PDA and PPHN, and newer technologies for drug administration, as well as other pharmacologic reponses in the neonate are vital in the development of safe and efficacious treatments for neonates. Many questions remain unanswered, and every clinician must make an effort to contribute to the knowledge and understanding of pharmacotherapy in this patient population.

Effects of a Breast Milk Diet on Enteral Feeding Outcomes of Neonates with Gastrointestinal Disorders

OBJECTIVE

The objective of this study was to assess whether a diet of ≥50% breast milk (BM) was associated with earlier transition off parenteral nutrition (PN) in neonates with gastrointestinal (GI) disorders.

METHODS

This retrospective study assessed enteral feeding outcomes of neonates with surgical GI disorders admitted within the first week of life to a single center between January 1, 2012 and August 10, 2015. Outcomes were assessed according to diet from the point of first enteral intake through 7 days of full enteral feeds. Diets were classified as 100%, ≥50%, or <50% BM.

RESULTS

One hundred sixty-three patients with an average gestational age of 36 weeks (range 28-40) and birthweight of 2570 g (range 1250-4900) were included. Significant differences in days to full enteral feeds between the 100% and <50% BM groups were found (median 21 versus 32 days; p = 0.023). There were no significant differences between the 100% and ≥50% BM (p = 0.05) or ≥50% versus <50% BM groups (p = 0.74). The 100% BM group had significantly fewer days on PN compared to the ≥50% BM group (median 21 versus 28.5 days, p = 0.034). Hospital length of stay was significantly shorter in the 100% BM group, which was discharged an average of 10 and 13.5 days sooner than the ≥50% and <50% BM groups (p < 0.05).

CONCLUSIONS

Neonates with specific GI disorders who received a 100% BM diet were found to achieve earlier full enteral feeds, have shorter PN courses, and be discharged from the hospital significantly sooner than those who received diets that included formula.

Enteral granulocyte-colony stimulating factor and erythropoietin early in life improves feeding tolerance in preterm infants: a randomized controlled trial

OBJECTIVE

To evaluate the efficacy and safety of enteral recombinant human granulocyte colony-stimulating factor (rhG-CSF) and recombinant human erythropoietin (rhEPO) in preventing feeding intolerance.

STUDY DESIGN

An interventional randomized control trial was conducted in 90 preterm infants born at ≤33 weeks gestational age. The neonates were assigned to 4 groups; 20 received rhG-CSF, 20 received rhEPO, 20 received both, and 30 received distilled water (placebo control). The test solution was given at the beginning of enteral feeding and was discontinued when enteral intake reached 100 mL/kg/day or after a maximum of 7 days, whichever came first. Feeding tolerance and adverse effects of treatment were assessed. Serum granulocyte colony-stimulating factor and erythropoietin levels were measured on days 0 and 7 of treatment.

RESULTS

All neonates tolerated the treatment without side effects. Neonates who received rhG-CSF and/or rhEPO had better feeding tolerance, as reflected by earlier achievement of 75 mL/kg/day, 100 mL/kg/day, and full enteral feeding of 150 mL/kg/day with earlier weight gain and a shorter hospital stay (P < .05). The risk of necrotizing enterocolitis was reduced from 10% to 0% in all treatment groups (P < .05). There was a shorter duration of withholding of feeding secondary to feeding intolerance among neonates receiving both rhG-CSF and rhEPO compared with those receiving placebo (P < .05). Serum levels of granulocyte colony-stimulating factor and erythropoietin at 0 and 7 days did not differ across the treatment groups.

CONCLUSIONS

Enteral administration of rhG-CSF and/or rhEPO improves feeding outcome and decreases the risk of necrotizing enterocolitis in preterm neonates. The mechanism may involve the prevention of villous atrophy.

Human milk composition: nutrients and bioactive factors

This article provides an overview of the composition of human milk, its variation, and its clinical relevance. The composition of human milk is the biological norm for infant nutrition. Human milk also contains many hundreds to thousands of distinct bioactive molecules that protect against infection and inflammation and contribute to immune maturation, organ development, and healthy microbial colonization. Some of these molecules (eg, lactoferrin) are being investigated as novel therapeutic agents. Human milk changes in composition from colostrum to late lactation, within feeds, by gestational age, diurnally, and between mothers. Feeding infants with expressed human milk is increasing.

Confirmation and prevention of intestinal barrier dysfunction and bacterial translocation caused by methotrexate

When intestinal barrier function is damaged bacterial translocation (BT) can occur. The injury to intestinal barrier function caused by chemotherapy has been investigated in some studies, however, definitive evidence of BT caused by chemotherapy is lacking. The aim of this study was to investigate small intestinal barrier dysfunction and BT and to evaluate the preventive effect of granulocyte colony-stimulating factor (G-CSF) on intestinal barrier dysfunction and BT in a rat model of chemotherapy. Sprague-Dawley rats were treated with methotrexate (MTX; 3.5 mg/kg) for 3 days to induce intestinal barrier dysfunction and BT, gavaged Escherichia coli TG1 labeled with green fluorescent protein for 2 days to track BT, and G-CSF (10 microg/kg) for 4 days to prevent intestinal barrier dysfunction and BT. Intestinal permeability was measured by the urinary excretion rate of lactulose and mannitol following administration by gavage. Representative tissue specimens from the mesenteric lymph nodes, spleen, liver, and kidney were aseptically harvested for bacteria culture in ampicillin-supplemented medium. Light microscopy was performed on intestinal samples. MTX induced significant mucosal and villous atrophy in ileum and significantly increased intestinal permeability. MTX also induced noticeable BT. G-CSF significantly increased the mucosal thickness and villous height of the ileum and decreased intestinal permeability and BT. In conclusion, MTX caused intestinal barrier dysfunction and BT, and G-CSF prevented intestinal barrier dysfunction and BT.

Hematopoietic growth factors in neonatal medicine: the use of enterally administered hematopoietic growth factors in the neonatal intensive care unit

The practice of complete bowel rest in prematurely delivered neonates and those who have undergone surgery for congenital anomalies of the gastrointestinal (GI) tract is common in neonatal intensive care units (NICU). However, increased recognition of the critical role of growth factors in GI development suggests that this practice might be modified to include the administration of synthetic amniotic fluid-like solutions designed to bridge the neonate between their intra-uterine environment and that of the NICU. This article reviews advances in administering synthetic amniotic fluid-like solutions in the NICU.