- Email: [email protected]
Is EGF the Holy Grail for NEC?
Is EGF the Holy Grail for NEC?
t has been 55 years since Schmid1 and Quaiser2 reported the pathological and clinical findings from 85 patients with a new disease that they named necrotizing enterocolitis (NEC). Much has been learned in the ensuing years, although the morbidity and mortality from this complex disease has not significantly improved, and there are no effective strategies for prevention or treatment, except for delaying preterm delivery and providing breast-milk feeding. Nonetheless, new information from basic science and clinical studies provides hope for identifying early predictive markers, clarifying the pathophysiologic cascade, and providing an effective preventive approach for this dreaded intestinal catastrophe. Epidermal growth factor (EGF) is one of many growth factors that stimulates receptors present on intestinal epithelium and promotes gut maturation and health. Studies have demonstrated the importance of EGF in preserving gut barrier function, increasing intestinal enzyme activity, and improving nutrient transport.3 In addition, EGF receptor (EGFR) knockout mice develop epithelial cell abnormalities and hemorrhagic necrosis of the intestine similar to neonatal NEC, suggesting that this molecule may play a role in the human condition.4 In support of this hypothesis, Halpern, Dvorak, and Clark and their colleagues have shown that EGF supplementation reduces the incidence of NEC in a neonatal rat model of NEC, in part by reducing apoptosis, barrier failure, and hepatic dysfunction, which have all been suggested as components of the pathophysiologic cascade.5-8 Human studies have suggested that urinary and salivary EGF (sEGF) levels correlate with gestational age and inversely with NEC.9,10 In this issue of The Journal, Warner et al11 report on a robust series of 327 sEGF levels from premature and term infants and demonstrate that (1) initial levels directly correlate with gestational age and increase with postnatal age; (2) lower sEGF during the first week was associated with an increased incidence of NEC; and (3) greater increases in sEGF values in subsequent weeks 2 and 3 was associated with increase NEC. Additional data of interest suggested that Caucasian patients, nil per os status, and postnatal antibiotics were associated with lower sEGF levels. These findings suggest that EGF may play a role in neonatal NEC, and leads one to consider EGF as a predictive marker of disease, as a component of the pathophysiologic cascade, and/or as a preventive approach. Neonatal NEC presents with acute clinical symptoms and signs, and in severe cases, it progresses rapidly to irreversible bowel necrosis and/or death. Early predictive markers
I
EGF EGFR NEC sEGF SNP
Editorials
Epidermal growth factor EGF receptor Necrotizing enterocolitis Salivary EGF Single nucleotide polymorphisms
might allow clinicians to alter feeding patterns and other clinical variables that might influence the incidence, onset, and severity of disease. Unfortunately, to date, the search for a reliable and consistent predictor of NEC has been unsuccessful. Investigators have considered blood cytokine values,12 blood and stool platelet activating factor (PAF) levels,13,14 blood cytosolic -glucosidase,15 c-reactive protein,16 intestinal and liver fatty acid binding protein,17 t-crypt antigen on red blood cells,18 volume of gastric residuals,19 and several other markers, but none have proven reliable, easy to measure, and clinically useful. In this context, it would be exciting if sEGF could be an early predictive marker for NEC. Unfortunately, because of the wide ranges of values and somewhat unpredictable changes from week to week observed in the Warner study, this measurement may be no more predictive of NEC than the most reliable indicator— gestational age. The pathophysiology of NEC has not been clearly elucidated, although substantial evidence suggests that in the preterm infant (who has an immature mucosal barrier) an unbalanced predilection toward the proinflammatory response results from stress factors that include feeding, bacterial colonization, and intestinal ischemia/reperfusion.20 Low levels of endogenous EGF as measured by sEGF during the first week of life by Warner et al are consistent with this hypothesis. EGF matures the mucosal barrier, decreases intestinal epithelial apoptosis, and down-regulates the proinflammatory response via signal transduction through EGF receptor and activation of PI3 kinase, JAK-STAT, and the Ras-MEK pathways.21 Of note, there are single nucleotide polymorphisms (SNPs) identified in the human EGF gene, and a higher risk for some clinical conditions such as malignant melanoma and gastric cancer have been associated with the EGF A61G genotype.22,23 Ethnic diversity has been associated with particular SNP patterns, and it seems likely that these differences can account for variations of disease incidence in different ethnic populations. Because epidemiologic data suggest an increase in NEC incidence in African-Americans,24 identification of SNP patterns in the EGF or EGFR gene (or multiple other genes) may help idenSee related article, p 358 tify the importance of a variety of molecules in Reprint requests: Michael Caplan, MD, the pathophysiology of Evanston Hospital, Perinatal Pediatrics, NEC. 2650 Ridge Avenue, Evanston, IL 602011718.E-mail: [email protected]. Regardless of the J Pediatr 2007;150:329-30 successful identification 0022-3476/$ - see front matter of an early predictive Copyright © 2007 Mosby Inc. All rights marker or a complete reserved. understanding of the 10.1016/j.jpeds.2007.01.027 329
pathophysiology of neonatal NEC, an effective preventive therapy is the ultimate “Holy Grail.” There have been multiple human trials reported to reduce the incidence of NEC, including human milk,25 IgA supplementation,26 prophylactic antibiotics,27 dexamethasone,28 polyunsaturated fatty acids,29 and, most recently, probiotic supplementation.30,31 Because of the inability to conclusively reproduce some results or because of some unexpected deleterious effects, human milk feeding is the only currently accepted modality for NEC prevention. Nonetheless, probiotic supplementation has garnered significant interest, and large phase III trials will soon be underway to confirm this potentially beneficial approach of gut colonization with commensal organisms. Of interest, human milk contains bioactive EGF with concentrations similar to those found in the saliva reported in the Warner study.32 Human milk is replete with multiple antimicrobial and antiinflammatory factors that might contribute to a reduction in NEC incidence, but it is intriguing to consider EGF as one of the key components. Further, it has been shown that postnatal steroid therapy increases EGF levels in preterm infants,33 and that probiotics can improve EGF binding to EGFR following pathogenic infection.34 These observations, coupled with the compelling animal studies and human data published by Warner et al and others, suggest that EGF supplementation in feedings may be an effective strategy for the prevention of NEC in preterm infants. In conclusion, there is a growing body of evidence that suggests abnormal EGF regulation in the preterm infant may contribute to the development of neonatal NEC. Warner et al should be congratulated for their extensive contributions to our understanding of the clinical relevance of EGF as well as the biochemical responses that regulate intestinal apoptosis, proliferation, and healing. Further investigation is needed to confirm the importance of EGF in the pathophysiologic cascade and to identify a potential role in the prevention of NEC. Michael Caplan, MD Perinatal Pediatrics, Evanston Hospital, Evanston, IL
REFERENCES 1. Schmid KO. [A specially severe form of enteritis in newborn, enterocolitis ulcerosa necroticans. I. Pathological anatomy]. Z Kinderheilkd 1952;8:114-35. 2. Quaiser K. [A specially severe form of enteritis in newborn, enterocolitis ulcerosa necroticans. II. Clinical studies]. Z Kinderheilkd 1952;8:136-52. 3. Warner BW, Warner BB. Role of epidermal growth factor in the pathogenesis of neonatal necrotizing enterocolitis. Semin Pediatr Surg 2005;14:175-80. 4. Miettinen PJ, Berger JE, Meneses J, Phung Y, Pedersen RA, Werb Z, et al. Epithelial immaturity and multiorgan failure in mice lacking epidermal growth factor receptor. Nature 1995;376:337-41. 5. Halpern MD, Holubec H, Clark JA, Saunders TA, Williams CS, Dvorak K, et al. Epidermal growth factor reduces hepatic sequelae in experimental necrotizing enterocolitis. Biol Neonate 2006;89:227-35. 6. Dvorak B, Halpern MD, Holubec H, Williams CS, McWilliam DL, Dominguez JA, et al. Epidermal growth factor reduces the development of necrotizing enterocolitis in a neonatal rat model. Am J Physiol Gastrointest Liver Physiol 2002;282:G156-G164. 7. Clark JA, Lane RH, Maclennan NK, Holubec H, Dvorakova K, Halpern MD, et al. Epidermal growth factor reduces intestinal apoptosis in an experimental model of necrotizing enterocolitis. Am J Physiol Gastrointest Liver Physiol 2005;288:G755-G762. 8. Clark JA, Doelle SM, Halpern MD, Saunders TA, Holubec H, Dvorak K, et al. Intestinal barrier failure during experimental necrotizing enterocolitis: protective effect of epidermal growth factor treatment. Am J Physiol Gastrointest Liver Physiol 2006;291:G938-49.
330
Editorials
9. Helmrath MA, Shin CE, Fox JW, Erwin CR, Warner BW. Epidermal growth factor in saliva and serum of infants with necrotising enterocolitis [letter]. Lancet 1998;351(9098):266-7. 10. Shin CE, Falcone RA Jr, Stuart L, Erwin CR, Warner BW. Diminished epidermal growth factor levels in infants with necrotizing enterocolitis. J Pediatr Surg 2000; 35:173-6; discussion 7. 11. Warner BB, Ryan AL, Seeger K, Leonard AC, Erwin CR, Warner BW. Ontogeny of salivary epidermal growth factor and necrotizing enterocolitis. J Pediatr 2007;150:358-63. 12. Harris MC, Costarino AT Jr, Sullivan JS, Dulkerian S, McCawley L, Corcoran L, et al. Cytokine elevations in critically ill infants with sepsis and necrotizing enterocolitis. J Pediatr 1994;124:105-11. 13. Caplan MS, Sun XM, Hseuh W, Hageman JR. Role of platelet activating factor and tumor necrosis factor-alpha in neonatal necrotizing enterocolitis. J Pediatr 1990;116:960-4. 14. Amer MD, Hedlund E, Rochester J, Caplan MS. Platelet-activating factor concentration in the stool of human newborns: effects of enteral feeding and neonatal necrotizing enterocolitis. Biol Neonate 2004;85:159-66. 15. Dimmitt RA, Glew R, Colby C, Brindle M, Skarsgard E, Moss RL. Serum cytosolic beta-glucosidase activity in a rat model of necrotizing enterocolitis. Pediatr Res 2003;54:462-5. 16. Pourcyrous M, Korones SB, Yang W, Boulden TF, Bada HS. C-reactive protein in the diagnosis, management, and prognosis of neonatal necrotizing enterocolitis. Pediatrics 2005;116:1064-9. 17. Guthmann F, Borchers T, Wolfrum C, Wustrack T, Bartholomaus S, Spener F. Plasma concentration of intestinal- and liver-FABP in neonates suffering from necrotizing enterocolitis and in healthy preterm neonates. Mol Cell Biochem 2002;239:227-34. 18. Klein RL, Novak RW, Novak PE. T-cryptantigen exposure in neonatal necrotizing enterocolitis. J Pediatr Surg 1986;21:1155-8. 19. Cobb BA, Carlo WA, Ambalavanan N. Gastric residuals and their relationship to necrotizing enterocolitis in very low birth weight infants. Pediatrics 2004;113(1 Pt 1):50-3. 20. Jilling T, Simon D, Lu J, Meng FJ, Li D, Schy R, et al. The roles of bacteria and TLR4 in rat and murine models of necrotizing enterocolitis. J Immunol 2006;177:3273-82. 21. Normanno N, De Luca A, Bianco C, Strizzi L, Mancino M, Maiello MR, et al. Epidermal growth factor receptor (EGFR) signaling in cancer. Gene 2006;366:2-16. 22. Hamai Y, Matsumura S, Matsusaki K, Kitadai Y, Yoshida K, Yamaguchi Y, et al. A single nucleotide polymorphism in the 5’ untranslated region of the EGF gene is associated with occurrence and malignant progression of gastric cancer. Pathobiology 2005;72:133-8. 23. Amend KL, Elder JT, Tomsho LP, Bonner JD, Johnson TM, Schwartz J, et al. EGF gene polymorphism and the risk of incident primary melanoma. Cancer Res 2004;64:2668-72. 24. Ryder RW, Shelton JD, Guinan ME. Necrotizing enterocolitis: a prospective multicenter investigation. Am J Epidemiol 1980;112:113-23. 25. Lucas A, Cole TJ. Breast milk and neonatal necrotising enterocolitis [see comments]. Lancet 1990;336(8730):1519-23. 26. Eibl MM, Wolf HM, Furnkranz H, Rosenkranz A. Prevention of necrotizing enterocolitis in low-birth-weight infants by IgA-IgG feeding. N Engl J Med 1988;319:1-7. 27. Siu YK, Ng PC, Fung SC, Lee CH, Wong MY, Fok TF, et al. Double blind, randomised, placebo controlled study of oral vancomycin in prevention of necrotising enterocolitis in preterm, very low birthweight infants. Arch Dis Child Fetal Neonatal Edition 1998;79:F105-F109. 28. Halac E, Halac J, Begue EF, Casanas JM, Indiveri DR, Petit JF, et al. Prenatal and postnatal corticosteroid therapy to prevent neonatal necrotizing enterocolitis: a controlled trial. J Pediatr 1990;117(1 Pt 1):132-8. 29. Carlson SE, Montalto MB, Ponder DL, Werkman SH, Korones SB. Lower incidence of necrotizing enterocolitis in infants fed a preterm formula with egg phospholipids. Pediatr Res 1998;44:491-8. 30. Lin HC, Su BH, Chen AC, Lin TW, Tsai CH, Yeh TF, et al. Oral probiotics reduce the incidence and severity of necrotizing enterocolitis in very low birth weight infants. Pediatrics 2005;115:1-4. 31. Bin-Nun A, Bromiker R, Wilschanski M, Kaplan M, Rudensky B, Caplan M, et al. Oral probiotics prevent necrotizing enterocolitis in very low birth weight neonates. J Pediatr 2005;147:192-6. 32. Dvorak B, Fituch CC, Williams CS, Hurst NM, Schanler RJ. Increased epidermal growth factor levels in human milk of mothers with extremely premature infants. Pediatr Res 2003;54:15-9. 33. Scott SM, Rogers C, Backstrom C. Dexamethasone therapy is associated with a rise in urinary epidermal growth factor concentrations in the preterm infant. Eur J Endocrinol 1995;132:326-30. 34. Resta-Lenert S, Barrett KE. Live probiotics protect intestinal epithelial cells from the effects of infection with enteroinvasive Escherichia coli (EIEC). Gut 2003;52:988-97.
The Journal of Pediatrics • April 2007
t has been 55 years since Schmid1 and Quaiser2 reported the pathological and clinical findings from 85 patients with a new disease that they named necrotizing enterocolitis (NEC). Much has been learned in the ensuing years, although the morbidity and mortality from this complex disease has not significantly improved, and there are no effective strategies for prevention or treatment, except for delaying preterm delivery and providing breast-milk feeding. Nonetheless, new information from basic science and clinical studies provides hope for identifying early predictive markers, clarifying the pathophysiologic cascade, and providing an effective preventive approach for this dreaded intestinal catastrophe. Epidermal growth factor (EGF) is one of many growth factors that stimulates receptors present on intestinal epithelium and promotes gut maturation and health. Studies have demonstrated the importance of EGF in preserving gut barrier function, increasing intestinal enzyme activity, and improving nutrient transport.3 In addition, EGF receptor (EGFR) knockout mice develop epithelial cell abnormalities and hemorrhagic necrosis of the intestine similar to neonatal NEC, suggesting that this molecule may play a role in the human condition.4 In support of this hypothesis, Halpern, Dvorak, and Clark and their colleagues have shown that EGF supplementation reduces the incidence of NEC in a neonatal rat model of NEC, in part by reducing apoptosis, barrier failure, and hepatic dysfunction, which have all been suggested as components of the pathophysiologic cascade.5-8 Human studies have suggested that urinary and salivary EGF (sEGF) levels correlate with gestational age and inversely with NEC.9,10 In this issue of The Journal, Warner et al11 report on a robust series of 327 sEGF levels from premature and term infants and demonstrate that (1) initial levels directly correlate with gestational age and increase with postnatal age; (2) lower sEGF during the first week was associated with an increased incidence of NEC; and (3) greater increases in sEGF values in subsequent weeks 2 and 3 was associated with increase NEC. Additional data of interest suggested that Caucasian patients, nil per os status, and postnatal antibiotics were associated with lower sEGF levels. These findings suggest that EGF may play a role in neonatal NEC, and leads one to consider EGF as a predictive marker of disease, as a component of the pathophysiologic cascade, and/or as a preventive approach. Neonatal NEC presents with acute clinical symptoms and signs, and in severe cases, it progresses rapidly to irreversible bowel necrosis and/or death. Early predictive markers
I
EGF EGFR NEC sEGF SNP
Editorials
Epidermal growth factor EGF receptor Necrotizing enterocolitis Salivary EGF Single nucleotide polymorphisms
might allow clinicians to alter feeding patterns and other clinical variables that might influence the incidence, onset, and severity of disease. Unfortunately, to date, the search for a reliable and consistent predictor of NEC has been unsuccessful. Investigators have considered blood cytokine values,12 blood and stool platelet activating factor (PAF) levels,13,14 blood cytosolic -glucosidase,15 c-reactive protein,16 intestinal and liver fatty acid binding protein,17 t-crypt antigen on red blood cells,18 volume of gastric residuals,19 and several other markers, but none have proven reliable, easy to measure, and clinically useful. In this context, it would be exciting if sEGF could be an early predictive marker for NEC. Unfortunately, because of the wide ranges of values and somewhat unpredictable changes from week to week observed in the Warner study, this measurement may be no more predictive of NEC than the most reliable indicator— gestational age. The pathophysiology of NEC has not been clearly elucidated, although substantial evidence suggests that in the preterm infant (who has an immature mucosal barrier) an unbalanced predilection toward the proinflammatory response results from stress factors that include feeding, bacterial colonization, and intestinal ischemia/reperfusion.20 Low levels of endogenous EGF as measured by sEGF during the first week of life by Warner et al are consistent with this hypothesis. EGF matures the mucosal barrier, decreases intestinal epithelial apoptosis, and down-regulates the proinflammatory response via signal transduction through EGF receptor and activation of PI3 kinase, JAK-STAT, and the Ras-MEK pathways.21 Of note, there are single nucleotide polymorphisms (SNPs) identified in the human EGF gene, and a higher risk for some clinical conditions such as malignant melanoma and gastric cancer have been associated with the EGF A61G genotype.22,23 Ethnic diversity has been associated with particular SNP patterns, and it seems likely that these differences can account for variations of disease incidence in different ethnic populations. Because epidemiologic data suggest an increase in NEC incidence in African-Americans,24 identification of SNP patterns in the EGF or EGFR gene (or multiple other genes) may help idenSee related article, p 358 tify the importance of a variety of molecules in Reprint requests: Michael Caplan, MD, the pathophysiology of Evanston Hospital, Perinatal Pediatrics, NEC. 2650 Ridge Avenue, Evanston, IL 602011718.E-mail: [email protected]. Regardless of the J Pediatr 2007;150:329-30 successful identification 0022-3476/$ - see front matter of an early predictive Copyright © 2007 Mosby Inc. All rights marker or a complete reserved. understanding of the 10.1016/j.jpeds.2007.01.027 329
pathophysiology of neonatal NEC, an effective preventive therapy is the ultimate “Holy Grail.” There have been multiple human trials reported to reduce the incidence of NEC, including human milk,25 IgA supplementation,26 prophylactic antibiotics,27 dexamethasone,28 polyunsaturated fatty acids,29 and, most recently, probiotic supplementation.30,31 Because of the inability to conclusively reproduce some results or because of some unexpected deleterious effects, human milk feeding is the only currently accepted modality for NEC prevention. Nonetheless, probiotic supplementation has garnered significant interest, and large phase III trials will soon be underway to confirm this potentially beneficial approach of gut colonization with commensal organisms. Of interest, human milk contains bioactive EGF with concentrations similar to those found in the saliva reported in the Warner study.32 Human milk is replete with multiple antimicrobial and antiinflammatory factors that might contribute to a reduction in NEC incidence, but it is intriguing to consider EGF as one of the key components. Further, it has been shown that postnatal steroid therapy increases EGF levels in preterm infants,33 and that probiotics can improve EGF binding to EGFR following pathogenic infection.34 These observations, coupled with the compelling animal studies and human data published by Warner et al and others, suggest that EGF supplementation in feedings may be an effective strategy for the prevention of NEC in preterm infants. In conclusion, there is a growing body of evidence that suggests abnormal EGF regulation in the preterm infant may contribute to the development of neonatal NEC. Warner et al should be congratulated for their extensive contributions to our understanding of the clinical relevance of EGF as well as the biochemical responses that regulate intestinal apoptosis, proliferation, and healing. Further investigation is needed to confirm the importance of EGF in the pathophysiologic cascade and to identify a potential role in the prevention of NEC. Michael Caplan, MD Perinatal Pediatrics, Evanston Hospital, Evanston, IL
REFERENCES 1. Schmid KO. [A specially severe form of enteritis in newborn, enterocolitis ulcerosa necroticans. I. Pathological anatomy]. Z Kinderheilkd 1952;8:114-35. 2. Quaiser K. [A specially severe form of enteritis in newborn, enterocolitis ulcerosa necroticans. II. Clinical studies]. Z Kinderheilkd 1952;8:136-52. 3. Warner BW, Warner BB. Role of epidermal growth factor in the pathogenesis of neonatal necrotizing enterocolitis. Semin Pediatr Surg 2005;14:175-80. 4. Miettinen PJ, Berger JE, Meneses J, Phung Y, Pedersen RA, Werb Z, et al. Epithelial immaturity and multiorgan failure in mice lacking epidermal growth factor receptor. Nature 1995;376:337-41. 5. Halpern MD, Holubec H, Clark JA, Saunders TA, Williams CS, Dvorak K, et al. Epidermal growth factor reduces hepatic sequelae in experimental necrotizing enterocolitis. Biol Neonate 2006;89:227-35. 6. Dvorak B, Halpern MD, Holubec H, Williams CS, McWilliam DL, Dominguez JA, et al. Epidermal growth factor reduces the development of necrotizing enterocolitis in a neonatal rat model. Am J Physiol Gastrointest Liver Physiol 2002;282:G156-G164. 7. Clark JA, Lane RH, Maclennan NK, Holubec H, Dvorakova K, Halpern MD, et al. Epidermal growth factor reduces intestinal apoptosis in an experimental model of necrotizing enterocolitis. Am J Physiol Gastrointest Liver Physiol 2005;288:G755-G762. 8. Clark JA, Doelle SM, Halpern MD, Saunders TA, Holubec H, Dvorak K, et al. Intestinal barrier failure during experimental necrotizing enterocolitis: protective effect of epidermal growth factor treatment. Am J Physiol Gastrointest Liver Physiol 2006;291:G938-49.
330
Editorials
9. Helmrath MA, Shin CE, Fox JW, Erwin CR, Warner BW. Epidermal growth factor in saliva and serum of infants with necrotising enterocolitis [letter]. Lancet 1998;351(9098):266-7. 10. Shin CE, Falcone RA Jr, Stuart L, Erwin CR, Warner BW. Diminished epidermal growth factor levels in infants with necrotizing enterocolitis. J Pediatr Surg 2000; 35:173-6; discussion 7. 11. Warner BB, Ryan AL, Seeger K, Leonard AC, Erwin CR, Warner BW. Ontogeny of salivary epidermal growth factor and necrotizing enterocolitis. J Pediatr 2007;150:358-63. 12. Harris MC, Costarino AT Jr, Sullivan JS, Dulkerian S, McCawley L, Corcoran L, et al. Cytokine elevations in critically ill infants with sepsis and necrotizing enterocolitis. J Pediatr 1994;124:105-11. 13. Caplan MS, Sun XM, Hseuh W, Hageman JR. Role of platelet activating factor and tumor necrosis factor-alpha in neonatal necrotizing enterocolitis. J Pediatr 1990;116:960-4. 14. Amer MD, Hedlund E, Rochester J, Caplan MS. Platelet-activating factor concentration in the stool of human newborns: effects of enteral feeding and neonatal necrotizing enterocolitis. Biol Neonate 2004;85:159-66. 15. Dimmitt RA, Glew R, Colby C, Brindle M, Skarsgard E, Moss RL. Serum cytosolic beta-glucosidase activity in a rat model of necrotizing enterocolitis. Pediatr Res 2003;54:462-5. 16. Pourcyrous M, Korones SB, Yang W, Boulden TF, Bada HS. C-reactive protein in the diagnosis, management, and prognosis of neonatal necrotizing enterocolitis. Pediatrics 2005;116:1064-9. 17. Guthmann F, Borchers T, Wolfrum C, Wustrack T, Bartholomaus S, Spener F. Plasma concentration of intestinal- and liver-FABP in neonates suffering from necrotizing enterocolitis and in healthy preterm neonates. Mol Cell Biochem 2002;239:227-34. 18. Klein RL, Novak RW, Novak PE. T-cryptantigen exposure in neonatal necrotizing enterocolitis. J Pediatr Surg 1986;21:1155-8. 19. Cobb BA, Carlo WA, Ambalavanan N. Gastric residuals and their relationship to necrotizing enterocolitis in very low birth weight infants. Pediatrics 2004;113(1 Pt 1):50-3. 20. Jilling T, Simon D, Lu J, Meng FJ, Li D, Schy R, et al. The roles of bacteria and TLR4 in rat and murine models of necrotizing enterocolitis. J Immunol 2006;177:3273-82. 21. Normanno N, De Luca A, Bianco C, Strizzi L, Mancino M, Maiello MR, et al. Epidermal growth factor receptor (EGFR) signaling in cancer. Gene 2006;366:2-16. 22. Hamai Y, Matsumura S, Matsusaki K, Kitadai Y, Yoshida K, Yamaguchi Y, et al. A single nucleotide polymorphism in the 5’ untranslated region of the EGF gene is associated with occurrence and malignant progression of gastric cancer. Pathobiology 2005;72:133-8. 23. Amend KL, Elder JT, Tomsho LP, Bonner JD, Johnson TM, Schwartz J, et al. EGF gene polymorphism and the risk of incident primary melanoma. Cancer Res 2004;64:2668-72. 24. Ryder RW, Shelton JD, Guinan ME. Necrotizing enterocolitis: a prospective multicenter investigation. Am J Epidemiol 1980;112:113-23. 25. Lucas A, Cole TJ. Breast milk and neonatal necrotising enterocolitis [see comments]. Lancet 1990;336(8730):1519-23. 26. Eibl MM, Wolf HM, Furnkranz H, Rosenkranz A. Prevention of necrotizing enterocolitis in low-birth-weight infants by IgA-IgG feeding. N Engl J Med 1988;319:1-7. 27. Siu YK, Ng PC, Fung SC, Lee CH, Wong MY, Fok TF, et al. Double blind, randomised, placebo controlled study of oral vancomycin in prevention of necrotising enterocolitis in preterm, very low birthweight infants. Arch Dis Child Fetal Neonatal Edition 1998;79:F105-F109. 28. Halac E, Halac J, Begue EF, Casanas JM, Indiveri DR, Petit JF, et al. Prenatal and postnatal corticosteroid therapy to prevent neonatal necrotizing enterocolitis: a controlled trial. J Pediatr 1990;117(1 Pt 1):132-8. 29. Carlson SE, Montalto MB, Ponder DL, Werkman SH, Korones SB. Lower incidence of necrotizing enterocolitis in infants fed a preterm formula with egg phospholipids. Pediatr Res 1998;44:491-8. 30. Lin HC, Su BH, Chen AC, Lin TW, Tsai CH, Yeh TF, et al. Oral probiotics reduce the incidence and severity of necrotizing enterocolitis in very low birth weight infants. Pediatrics 2005;115:1-4. 31. Bin-Nun A, Bromiker R, Wilschanski M, Kaplan M, Rudensky B, Caplan M, et al. Oral probiotics prevent necrotizing enterocolitis in very low birth weight neonates. J Pediatr 2005;147:192-6. 32. Dvorak B, Fituch CC, Williams CS, Hurst NM, Schanler RJ. Increased epidermal growth factor levels in human milk of mothers with extremely premature infants. Pediatr Res 2003;54:15-9. 33. Scott SM, Rogers C, Backstrom C. Dexamethasone therapy is associated with a rise in urinary epidermal growth factor concentrations in the preterm infant. Eur J Endocrinol 1995;132:326-30. 34. Resta-Lenert S, Barrett KE. Live probiotics protect intestinal epithelial cells from the effects of infection with enteroinvasive Escherichia coli (EIEC). Gut 2003;52:988-97.
The Journal of Pediatrics • April 2007