Incidence Of Neonatal Necrotizing Enterocolitis Research Articles

Enterocolite necrosante neonatal: relato de caso e revisão de literatura

Neonatal necrotizing enterocolitis (NEC) is a syndrome characterized by inflammation and ischemic necrosis of the gastrointestinal tract that can course with variable clinical manifestations: such as abdominal distension, bilious vomiting, hematoquezia, frequent gastric waste, decreased hydro-air noises, fecal changes. The condition is usually associated with systemic signs (pallor, apnea, hypoactivity, dysthermias). NEC can manifest with partial intestinal necrosis and have complete recovery, requiring only clinical treatment. Case report: newborn (NB) of T.A.A., female, premature (33 weeks and 5 days), extremely low weight (888g), APGAR 8/9, referred to the Neonatal Intensive Care Unit (ICU NEO). On the 1st day of life, he presented significant abdominal distension and bilious debt by the orogastric tube (SOG). It eliminated meconium after rectal stimulation, with 43 hours of life. He maintained abdominal distension until the 10th day of life, progressing, with progressive improvement (reduction of abdominal distension, change in the aspect of the debt by SOG), after the institution of adequate therapy. On the 11th day of life, he started a minimal enteral diet, progressing gradually, achieving success in diet progression. Enterocolitis is one of the most frequent gastrointestinal emergencies in neonates, most frequently affecting premature newborns, especially those born with very low birth weight. Studies indicate the recent increase in the incidence of NEC in NEO ICUs, in several countries, due to the increased survival of premature newborns. Therefore, there is a need for a greater dissemination of knowledge about the pathology; mainly among health professionals who work in these units.

Enterocolite necrosante neonatal: relato de caso e revisão de literatura

Neonatal necrotizing enterocolitis (NEC) is a syndrome characterized by inflammation and ischemic necrosis of the gastrointestinal tract that can course with variable clinical manifestations: such as abdominal distension, bilious vomiting, hematoquezia, frequent gastric waste, decreased hydro-air noises, fecal changes. The condition is usually associated with systemic signs (pallor, apnea, hypoactivity, dysthermias). NEC can manifest with partial intestinal necrosis and have complete recovery, requiring only clinical treatment. Case report: newborn (NB) of T.A.A., female, premature (33 weeks and 5 days), extremely low weight (888g), APGAR 8/9, referred to the Neonatal Intensive Care Unit (ICU NEO). On the 1st day of life, he presented significant abdominal Residência Pediátrica; 2023: Ahead of Print. DOI: 10.25060/residpediatr-2023-567 distension and bilious debt by the orogastric tube (SOG). It eliminated meconium after rectal stimulation, with 43 hours of life. He maintained abdominal distension until the 10th day of life, progressing, with progressive improvement (reduction of abdominal distension, change in the aspect of the debt by SOG), after the institution of adequate therapy. On the 11th day of life, he started a minimal enteral diet, progressing gradually, achieving success in diet progression. Enterocolitis is one of the most frequent gastrointestinal emergencies in neonates, most frequently affecting premature newborns, especially those born with very low birth weight. Studies indicate the recent increase in the incidence of NEC in NEO ICUs, in several countries, due to the increased survival of premature newborns. Therefore, there is a need for a greater dissemination of knowledge about the pathology; mainly among health professionals who work in these units.

Safety and efficacy of probiotics in the prevention of necrotizing enterocolitis in premature and/or low-birthweight infants: a systematic review and meta-analysis.

BackgroundNeonatal necrotizing enterocolitis (NEC) is a serious pediatric gastrointestinal disease and a cause of death in neonates, especially in premature infants. The addition of probiotics to the diet can reduce the incidence and severity of neonatal NEC. This meta-analysis explored the preventive effect of probiotics on NEC.MethodsEndnote X9 software was used to search for relevant studies in the Ovid, Embase, PubMed, and Web of Science databases. The search terms were “probiotics” and “necrotizing enterocolitis”. After retrieval, screening, and quality evaluation of the studies, Stata 16.0 software was used to analyze the data.ResultsA total of 10 studies, which collectively included 3,227 patients, were selected for analysis. Of them, 5 used a multiple-strain probiotics, and 5 used single-strain probiotic. Meta-analysis showed that treatment with probiotics could reduce the incidence of severe NEC [risk ratio (RR) =0.66; 95% confidence interval (CI): (0.50, 0.87); Z=−2.978; P=0.003], reduce mortality in underweight premature children [RR =0.81; 95% CI: (0.70, 0.94); Z=−2.864; P=0.004], and reduce the incidence of feeding intolerance [RR =0.78; 95% CI: (0.67, 0.90); Z=−3.280; P=0.001].DiscussionThe addition of probiotics to the diet of low-birthweight and premature infants can reduce the incidence of severe NEC and reduce related mortality rates.

Activated M1 macrophages suppress c-kit expression via TNF-α-mediated upregulation of miR-222 in Neonatal Necrotizing Enterocolitis.

Activation of intestinal macrophages is implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC), yet its precise mechanisms remain unclear. The purpose of this study is to investigate the role of macrophages and TNF-α via an inflammatory MicroRNA in NEC. Immunofluorescence (IF) staining of CD68, iNOS, and Arg-1 was employed to identify phenotypes of macrophage in the intestines of NEC infants and NEC mice. Expression of TNF-α, c-kit, and miR-222 was evaluated by qRT-PCR, Western blot, and immunochemical staining from the tissue samples. Large number of M1 macrophage infiltration was found in the NEC intestines. Expression of CD68, iNOS, and TNF-α were significantly increased, while c-kit was decreased distinctly in the NEC group. In the early phase of NEC mouse model, inhibition of M1 macrophages reduced the incidence of NEC and intestinal inflammation. We found that TNF-α upregulated the expression of miRNA-222 and inhibited the expression of c-kit. Conversely, such decrease of c-kit expression could be reversed by miR-222 antagonists. Furtherly, dual-luciferase assay confirmed that c-kit can be inhibited by miR-222 directly. Macrophages activation in NEC intestine results in an increased inflammatory response and TNF-α production, accompanied with miR-222 upregulation and c-kit suppression. Modulations of M1 macrophages, TNF-α or miR-222 may be potential therapeutic targets for NEC treatment.

Protective effects of different doses of human milk on neonatal necrotizing enterocolitis.

We aim to summarize the evidence focusing on the effects of various doses of human milk on the risk of neonatal necrotizing enterocolitis (NEC). The eligible articles in the study were those investigating the association between human milk and NEC published before June 26, 2019, in the PubMed, EMBASE, the Cochrane Library, VIP database, CNKI database, and Wangfang database. The included criteria were as follows: premature infants of <37 weeks; randomly controlled trials (RCTs); those fed by mother's own milk or donor human milk; studies focused on the comparison of human milk and formula milk, involving various breast milk doses; and NEC-related studies. Compared with the exclusive formula, the incidence of NEC in the infants fed by exclusive human milk was significantly lower. The incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of partial human milk [risk ratio (RR) = 0.54, 95% confidence interval (95% CI): 0.36–0.79, P < .05]. The incidence of NEC in the infants fed mainly by human milk was significantly lower than that of mainly fed by formula. Incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of any formula (RR = 0.49, 95% CI: 0.34–0.71, P < .05). In summary, this meta-analysis was based on the RCTs involving the prevention of NEC using human milk. Exclusive human milk and partial human milk reduced the incidence of NEC in premature infants, especially in the those fed by high proportion of human milk. In addition, more RCTs are needed to further validate such conclusion.

Analysis of risk factors for neonatal transfusion-associated necrotizing enterocolitis

Objective To investigate the clinical relevant factors associated with transfusion associated necrotizing enterocolitis (TANEC) in order to reduce the incidence of neonatal necrotizing enterocolitis (NEC). Methods The clinical data of neonates admitted to the First Hospital of Lanzhou University and received blood transfusion therapy from January 2017 to June 2018 were collected, including perinatal factors, basic conditions of children, and comorbidities.According to the occurrence or absence of NEC within 48 hours after transfusion, the patients were divided into TANEC group and no-TANEC group.The clinical data of the two groups were compared. Results Univariate analysis showed that there were statistical differences (P<0.05) in the mode of delivery, gestational age, birth weight, neonatal sepsis, patent ductus arteriosus(PDA), neonatal respiratory distress syndrome (NRDS), and anemia.The logistic multivariate analysis revealed that gestational age(P<0.05, OR=0.772, 95%CI: 0.684-0.871), the birth weight(P<0.05, OR=0.236, 95%CI: 0.079-0.711)were protect fators of TANEC, the degree of anemia(mode 1: P<0.05, OR=3.129, 95%CI: 1.003-9.756; mode 2: P<0.05, OR=3.449, 95%CI: 1.024-11.609)and sepsis (mode 1: P<0.05, OR=6.327, 95%CI: 1.732-23.720; mode 2: P<0.05, OR=8.154, 95%CI: 2.122-31.336)were significant risk fators for TANEC. Conclusion The factors leading to the occurrence of TANEC are various.When transfused, the greater the gestational age, the higher the birth weight, the lower the risk of developing NEC.The more severe the combination of neonatal sepsis and anemia, the higher the risk of developing TANEC.Clinically, comprehensive measures should be taken to prevent neonatal anemia.According to the specific conditions of the children and the degree of anemia, a reasonable clinical strategy should be formulated to avoid blood transfusion to reduce the incidence of TANEC and improve the prognosis of the children. Key words: Neonate; Anemia; Blood transfusion; Transfusion-associated necrotizing enterocolitis; Sepsis

Analysis of clinical characteristics of 623 cases of neonatal necrotizing enterocolitis

Objective To investigate the incidence, mortality and clinical characteristics of neonatal necroti-zing enterocolitis(NEC) in Shanghai. Methods A retrospective study was conducted in 623 cases of NEC from January 2010 to December 2015 at Children′s Hospital of Fudan University.All analysis were performed by using the statistical software package Stata 12.0. Results Six hundred and twenty-three NEC neonates were included in the study, and 485 of them were preterm infants, including 304 cases of stage 1, 176 cases of stage 2 and 143 cases of stage 3.The gestational age was (33.2±3.9) weeks, and the birth weight was (1 979.7±813.5) g. The incidence of NEC in Children′s Hospital of Fudan University was 1.29% (410/31 662 cases), and that of the stage 2 and stage 3 was 1.01% (319/31 662 cases). The gestational age was smaller and birth weight was less in the stage 2 and stage 3 group than that in the stage 1 group (all P<0.001). The percentage of cases received breast milk feeding was 7%.The rate of prophylactic antibiotics within 3 days of their life and ibuprofen for patent ductus arteriosus prior to NEC in stage 1 group was lower than that in stage-2 and stage 3 groups (all P<0.05). The most common clinical presentations were abdominal distension(71.75%, 447/623 cases), decreased bowel sounds(56.02%, 143/623 cases), looked sick (45.43%, 283/623 cases) and bloody stools(40.45%, 252/623 cases). The bowel perforation rate of the preterm and the term infants was 17.73%(86/485 cases)and 13.04%(18/138 cases), respectively.The patients who received surgical management took up 25.36%.The neonates were most commonly complicated with post-NEC stenosis (10.27%) and a culture-proven sepsis(7.87%). The count of white blood cell (WBC)<4×109/L and platelet<100×109/L raising level in stage 2 and stage 3 were higher than those in stage 1(all P<0.05). The antibiotics used for NEC were metronidazole (69.34%), carbapenems (65.65%), cephalosporins(61.16%) and penicillins(58.59%). The prognosis of NEC showed that cure cases occupied 65.49%, discharged cases with a better condition 19.58%, and death cases occupied 14.93%.The mortality of stage 3 accounted for 45.46%. Conclusions Newborn NEC mainly had gestational age of 28-34 weeks and birth weight of 1 000-1 999 g, respectively.The incidence of NEC 1.29% and it is decreasing year by year, while that of very-low-birth weight(VLBW) is still as high as 11.82%.The mortality of NEC occupies 14.93%, while that of stage 3 reaches as high as 45.46%. Key words: Infant, newborn; Infant, premature; Necrotizing enterocolitis; Influencing factor

Neonatal infection and neonatal necrotizing enterocolitis

Neonatal necrotizing enterocolitis(NEC) is a common critical disease of the digestive system in neonatal period.In severe case, it may even endanger the lives of newborn.The mechanism of NEC is complex and uncertain.Neonatal infection is one of the most important aspects of the mechanism.The immature digestive system, intestinal barrier structure and function in premature infants, the innate defects of intestinal immunity and the abnormal intestinal bacterial colonization can lead to a high incidence of NEC in premature infants.Currently, there is limited specific treatment.It will benefit for reducing incidence of NEC if prevention is targeted on the found of risk factors. Key words: Infection; Necrotizing enterocolitis; Neonates,

Early versus Late Enteral Feeding in Preterm Intrauterine Growth Restricted Neonates with Antenatal Doppler Abnormalities: An Open-Label Randomized Trial.

Enteral feeding in preterm neonates with intrauterine growth restriction (IUGR) and absent or reversed end diastolic flow (AREDF) on umbilical artery (UA) Doppler is delayed owing to an increased risk of necrotizing enterocolitis (NEC). Delaying enteral feeding with longer duration of parenteral nutrition (PN) carries an increased risk of sepsis. To study early versus late feeding in preterm IUGR neonates for time required to attain sufficient feed volume to discontinue PN and increased risk of NEC or feed intolerance (FI). Open-label randomized controlled trial. Tertiary care neonatal unit and fetal-maternal medicine unit in India. Preterm intrauterine growth restricted neonates' ≤32 weeks with AREDF on UA Doppler enrolled from 1 January 2014 to 31 July 2015. Randomized to receive early or late feeding using mothers own or donor breast milk as per a feed initiation and advancement protocol. Time in days required to attain sufficient feed volume allowing discontinuation of PN and incidence of NEC in neonates fed early versus late. There were 77 eligible neonates. Sixty-two neonates were included and stratified as extreme preterm (27-29 weeks) (n = 20) and very preterm (30-32 weeks) (n = 42). Ten extreme preterm and 21 very preterm neonates were randomized to each early feeding and late feeding arm. There was a significantly faster attainment of sufficient feeds in the early feeding arm of both the stratified groups [extreme preterm: median 14 days (Interquartile range IQR: 12-15) compared with 18 days (IQR: 18-20), hazard ratio (HR): 1.59, 95% CI: 0.626-4.078; very preterm: 12 days (IQR: 10-14) as compared with 16 days (IQR 15-17), HR: 1.89, 95% CI: 1.011-3.555]. There was no difference in the incidence of NEC, FI and combined outcome of NEC and FI. Early feeding in preterm IUGR neonates with AREDF on antenatal UA Doppler allowed earlier discontinuation of PN, allowing birth weight to be regained earlier and did not increase the incidence of NEC and FI.

Protective Effects of Bifidobacterium on Intestinal Barrier Function in LPS-Induced Enterocyte Barrier Injury of Caco-2 Monolayers and in a Rat NEC Model.

Zonulin protein is a newly discovered modulator which modulates the permeability of the intestinal epithelial barrier by disassembling intercellular tight junctions (TJ). Disruption of TJ is associated with neonatal necrotizing enterocolitis (NEC). It has been shown bifidobacterium could protect the intestinal barrier function and prophylactical administration of bifidobacterium has beneficial effects in NEC patients and animals. However, it is still unknown whether the zonulin is involved in the gut barrier dysfunction of NEC, and the protective mechanisms of bifidobacterium on intestinal barrier function are also not well understood. The present study aims to investigate the effects of bifidobacterium on intestinal barrier function, zonulin regulation, and TJ integrity both in LPS-induced enterocyte barrier injury of Caco-2 monolayers and in a rat NEC model. Our results showed bifidobacterium markedly attenuated the decrease in transepithelial electrical resistance and the increase in paracellular permeability in the Caco-2 monolayers treated with LPS (P < 0.01). Compared with the LPS group, bifidobacterium significantly decreased the production of IL-6 and TNF-α (P < 0.01) and suppressed zonulin release (P < 0.05). In addition, bifidobacterium pretreatment up-regulated occludin, claudin-3 and ZO-1 expression (P < 0.01) and also preserved these proteins localization at TJ compared with the LPS group. In the in vivo study, bifidobacterium decreased the incidence of NEC from 88 to 47% (P < 0.05) and reduced the severity in the NEC model. Increased levels of IL-6 and TNF-α in the ileum of NEC rats were normalized in bifidobacterium treated rats (P < 0.05). Moreover, administration of bifidobacterium attenuated the increase in intestinal permeability (P < 0.01), decreased the levels of serum zonulin (P < 0.05), normalized the expression and localization of TJ proteins in the ileum compared with animals with NEC. We concluded that bifidobacterium may protect against intestinal barrier dysfunction both in vitro and in NEC. This protective effect is associated with inhibition of proinflammatory cytokine secretion, suppression of zonulin protein release and improvement of intestinal TJ integrity.

Potential Benefits of Probiotics for Preterm Infants: A Review

Preterm infants are particularly susceptible to abnormal colonization and are therefore prone to systemic infections due to increased intestinal permeability to potentially pathogens. Abnormal pattern of colonization in pre-term infants may contribute to the pathogenesis of neonatal Necrotizing Enterocolitis (NEC), an acquired gastrointestinal (GI) disease associated with significant morbidity and mortality. Introduction of foods containing probiotic cultures may be advantageous as probiotics prevented gut colonization by abnormal flora. Endeavour has been made to explore the mechanism of gut colonization, suitability of breast milk for preterm infants, effect of administration of probiotics to preterm infants and its safety concerns. Human milk is also suitable for the management of premature infants but fortified breast milk may be a preferred choice and not the pooled pasteurized breast milk. Based upon Randomized Controlled Trials administration of probiotic in preterm infants with a birth weight &gt;1000 g could be recommended due to significantly reduction in incidence of NEC and no systemic infections or serious adverse events was reported. Administration of probiotics in preterm neonates is recommended but further research is emerging for its routine application. Probiotic supplementation in preterm neonates exhibited good safety profile and did not show any side effects and can be recommended for preterm infants but not for extremely low birth weight (ELBW) infants [1, 2].

Clinical observation of very low birth weight infants with early trace depth hydrolyzed protein formula

Objective To study the effect of early trace depth hydrolyzed protein formula and infant formula milk on very low birth weight (VLBW) infants of the gastrointestinal tolerance,growth and development,and provide scientific basis for early enteral feeding VLBW.Methods 126 premature infants with birth weight lower than 1 500 g were randomly divided into observation group (63 cases) and control group (63 cases).On the basis of routine treatment,the observation group was given early trace depth hydrolyzed protein formula,the control group was given early minimal preterm formula milk.We oberserved gastrointestinal tolerance,complications and growth monitoring of two groups.Results Period to regain their birth weight,up to full enteral feeding days of age,hospitalization days,discharge rate of extrauterine growth retardation,the incidence of feeding intolerance,the incidence of neonatal necrotizing enterocolitis,feeding dyspeptic diarrhea incidence in observation group were 12.81 d,25.76 d,37.95 d,23.8％,14.3％,6.3％,3.2％.The data in control group were 16.02 d,27.75 d,45.49 d,42.9％,30.2％,19％,12.7％ respectively.There was significant difference between two groups (P ＜ 0.05).Conclusion To carry out early trace depth hydrolysis protein can reduce the risk of the incidence of complications in VLBW infant which has good promotion on the recent growth and suitable for clinical use. Key words: Very low birth weight; Early minimal feeding; Depth hydrolyzed protein; Clinical observation

Analysis of the difference of risk factors between each stage of necrotizing enterocolitis

Objective To discuss the differences of the risk factors between Bell Stage Ⅰ and Stage Ⅱ/Ⅲ of neonatal necrotizing enterocolitis(NEC), in order to provide theoretical basis for better preventing and treating NEC of each stages. Methods Eighty seven NEC neonates' references from 2009 to 2011 were all analyzed retrospectively to find out relative risk factors.They were divided into 2 groups according to Bell stage: stage Ⅰ and stage Ⅱ/Ⅲ.Twenty four items were compared between the 2 groups, including perinatal factors, feeding methods, complications, RBC perfusion, etc, using SPSS 17.0 software to make single factor analysis, for the sake of finding out relative risk factors. Results The comparison of gestational age, birth weight, onset age, and onset weight between 2 groups has no statistical significance(P>0.05). The mortality of stage Ⅱ/Ⅲ was higher than stage Ⅰ(P<0.05). Seven of 24 items have statistical difference in the comparison(P<0.05), including: Gestational diabetes mellitus, amniotic fluid disorders, respiratory failure, hypothyroid, anemia, sepsis, RBC perfusion, indicating that these items may correlate to incidence and severity of NEC. Conclusions Gestational diabetes mellitus, amniotic fluid disorders, respiratory failure, hypothyroid, anemia, sepsis, RBC perfusion are risk factors that influence the severity of NEC. Key words: Necrotizing enterocolitis; Risk factor; Prognosis

Erythropoietin Protects Epithelial Cells from Excessive Autophagy and Apoptosis in Experimental Neonatal Necrotizing Enterocolitis

Neonatal necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of preterm infants. Increased intestinal epithelium permeability is an early event in NEC pathogenesis. Autophagy and apoptosis are induced by multiple stress pathways which may impact the intestinal barrier, and they have been associated with pathogenesis of diverse gastrointestinal diseases including inflammatory bowel disease. Using both in vitro and in vivo models, this study investigates autophagy and apoptosis under experimental NEC stresses. Furthermore this study evaluates the effect of erythropoietin (Epo), a component of breast milk previously shown to decrease the incidence of NEC and to preserve intestinal barrier function, on intestinal autophagy and apoptosis. It was found that autophagy and apoptosis are both rapidly up regulated in NEC in vivo as indicated by increased expression of the autophagy markers Beclin 1 and LC3II, and by evidence of apoptosis by TUNEL and cleaved caspase-3 staining. In the rat NEC experimental model, autophagy preceded the onset of apoptosis in intestine. In vitro studies suggested that Epo supplementation significantly decreased both autophagy and apoptosis via the Akt/mTOR signaling pathway and the MAPK/ERK pathway respectively. These results suggest that Epo protects intestinal epithelium from excessive autophagy and apoptosis in experimental NEC.

Effects of heparin-binding epidermal growth factor-like growth factor on mitochondrial pathway of apoptosis in neonatal rats with necrotizing enterocolitis

Objective To investigate the effect of heparin-binding epidermal growth factor-like growth factor (HB-EGF) on mitochondrial pathway of apoptosis in rats with neonatal necrotizing enterocolitis (NEC).Methods Sprague-Dawley neonatal rats were randomly divided into three groups with ten in each.NEC group rats were formula fed,and hypoxia exposed by 100％ N2 for 90 s and cold stress at 4 ℃ for 10 min twice a day for three days.Additionally,rats in HB-EGF group received HB-EGF 800μg/kg by gavage four times a day for three days.Rats in control group were given breast milk feeding for three days without any interventions.Seventy-two hours after born,all neonatal rats were sacrificed after fasting for 12 h,from which the terminal ileum was removed.HE-staining was done for histologic evaluation.Mitochondrial ultrastructure was observed under electron microscopy.Cytochrome C was detected by immunohistochemical analysis and apoptosis inducing factor (AIF) and apoptotic protease activating factor-1 (APAF-1) were measured by Western blot.Analysis of variance and q-test were used to compare the difference among groups.Results (1) The incidence of NEC in HB-EGF group was lower than that in NEC group (2/10 vs 9/10,x2 =7.27,P＜0.01).(2) In NEC group,mitochondria in epithelial cells and muscle cells of intestine were significantly swelling,appearing many electron-lucent zones in matrix.Ultrastructure of mitochondria were severely damaged.In HB-EGF group,mitochondria were less swelling and showed milder damage than those in NEC group.(3) The expression of cytochrome C in ileal tissue in NEC group was higher than that in control group (0.030±0.018 vs 0.002±0.001,q=6.15,P＜0.01).The expression of cytoehrome C in ileal tissue in HB-EGF group was lower than that in NEC group (0.014±0.018 vs 0.030±0.018,q=3.53,P＜0.05).The expression of APAF-1 and AIF in NEC group was higher than those in control group (1.364±0.299 vs 0.215±0.033,q=15.31,P＜0.05;0.181±0.050 vs0.127±0.045,q=3.71,P＜0.05).Compared to NEC group,the expression of APAF-1 was lower (0.455±0.123 vs 1.364±0.299,q=4.04,P＜0.05) and the expression of AIF was higher (0.289±0.045 vs 0.181±0.050,q=7.32,P＜0.05) in HB-EGF group.Conclusions HB-EGF could reduce the incidence of NEC in neonatal rats by inhibiting the mitochondrial pathway related apoptosis through down regulation of APAF-1. Key words: Enterocolitis, necrotizing; Intercellular signaling peptides and proteins; Apoptotic protease-activating factor 1 ; Apoptosis ; Mitochondria ; Rats

Heparin-Binding EGF-Like Growth Factor (HB-EGF): Can We Add this to Breast Milk in the Future to Prevent Necrotizing Enterocolitis

We have previously shown that heparin-binding EGF-like growth factor (HB-EGF), a glycoprotein that is naturally present in low levels in human breast milk, protects the intestines from injury in several different animal models, including a model of neonatal necrotizing enterocolitis (NEC). In addition to its trophic effects which are mediated by its ability to stimulate intestinal epithelial cell proliferation and migration, HB-EGF prevents the production of injurious mediators of intestinal injury, and acts as an anti-inflammatory factor. More recently, we have shown that HB-EGF protects intestinal stem cells (ISC) from injury in our animal model of NEC. We believe that the ability of HB-EGF to protect the intestines from NEC may be due, in large part, to its effects on ISC. Ongoing studies in our lab have examined the ability of HB-EGF to act synergistically with transplanted mesenchymal stem cells (MSC) in protection of the intestines from NEC. HB-EGF stimulates MSC proliferation and migration in vitro, and promotes transplanted MSC engraftment into injured intestine in vivo. The administration of both HB-EGF and MSC decrease the incidence and severity of NEC, and increased survival, in our model. In addition, we have recently shown that HB-EGF protects the enteric nervous system from injury, and acts to promote intestinal motility. Collectively, these findings lend further support for the use of HB-EGF in the future as a potential therapy for the prevention or treatment of NEC.

Erythropoietin Protects Intestinal Epithelial Barrier Function and Lowers the Incidence of Experimental Neonatal Necrotizing Enterocolitis

The impermeant nature of the intestinal barrier is maintained by tight junctions (TJs) formed between adjacent intestinal epithelial cells. Disruption of TJs and loss of barrier function are associated with a number of gastrointestinal diseases, including neonatal necrotizing enterocolitis (NEC), the leading cause of death from gastrointestinal diseases in preterm infants. Human milk is protective against NEC, and the human milk factor erythropoietin (Epo) has been shown to protect endothelial cell-cell and blood-brain barriers. We hypothesized that Epo may also protect intestinal epithelial barriers, thereby lowering the incidence of NEC. Our data demonstrate that Epo protects enterocyte barrier function by supporting expression of the TJ protein ZO-1. As immaturity is a key factor in NEC, Epo regulation of ZO-1 in the human fetal immature H4 intestinal epithelial cell line was examined and demonstrated Epo-stimulated ZO-1 expression in a dose-dependent manner through the PI3K/Akt pathway. In a rat NEC model, oral administration of Epo lowered the incidence of NEC from 45 to 23% with statistical significance. In addition, Epo treatment protected intestinal barrier function and prevented loss of ZO-1 at the TJs in vivo. These effects were associated with elevated Akt phosphorylation in the intestine. This study reveals a novel role of Epo in the regulation of intestinal epithelial TJs and barrier function and suggests the possible use of enteral Epo as a therapeutic agent for gut diseases.

Bifidobacterium bifidum improves intestinal integrity in a rat model of necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in premature infants. Oral administration of probiotics has been suggested as a promising strategy for prevention of NEC. However, little is known about the mechanism(s) of probiotic-mediated protection against NEC. The aim of this study was to evaluate the effects of Bifidobacterium bifidum treatment on development of NEC, cytokine regulation, and intestinal integrity in a rat model of NEC. Premature rats were divided into three groups: dam fed (DF), hand fed with formula (NEC), or hand fed with formula supplemented with 5 x 10(6) CFU B. bifidum per day (B. bifidum). All groups were exposed to asphyxia and cold stress to develop NEC. Intestinal injury, mucin and trefoil factor 3 (Tff3) production, cytokine levels, and composition of tight junction (TJ) and adherens junction (AJ) proteins were evaluated in the terminal ileum. B. bifidum decreased the incidence of NEC from 57 to 17%. Increased levels of IL-6, mucin-3, and Tff3 in the ileum of NEC rats was normalized in B. bifidum treated rats. Reduced mucin-2 production in the NEC rats was not affected by B. bifidum. Administration of B. bifidum normalized the expression and localization of TJ and AJ proteins in the ileum compared with animals with NEC. In conclusion, administration of B. bifidum protects against NEC in the neonatal rat model. This protective effect is associated with reduction of inflammatory reaction in the ileum, regulation of main components of mucus layer, and improvement of intestinal integrity.

Captopril reduces the severity of bowel damage in a neonatal rat model of necrotizing enterocolitis

Selective mesenteric ischemia may result from activation of the renin-angiotensin system during periods of shock and is implicated in the pathogenesis of neonatal necrotizing enterocolitis (NEC). We investigated the effectiveness of captopril, an angiotensin-converting enzyme inhibitor, in reducing the severity of bowel damage in a neonatal rat model of NEC. Necrotizing enterocolitis was induced by a combination of gavage feeding of hypertonic formula, hypoxia, and oral lipopolysaccharide (LPS). Rats were randomly divided into 3 groups: group A, control (breast fed; n = 20); group B, NEC (gavage/hypoxia/LPS; n = 31); group C, NEC with captopril 20 mg/kg per dose with the formula for 4 days (gavage/hypoxia/LPS/captopril; n = 35). Pups were killed after 4 days. Incidence of NEC was evaluated microscopically. Severity of bowel damage was higher in the NEC group compared to controls and was reduced by administration of captopril. Dilatation of the intestinal vasculature was observed in the captopril group. There were no cases of NEC in the controls; the incidence increased to 55% in NEC group and reduced to 29% by captopril. In this model of neonatal NEC, captopril supplementation of formula reduces the severity of intestinal damage and the incidence of NEC, presumably by affecting mesenteric blood flow.

Portal venous gas and surgical outcome of neonatal necrotizing enterocolitis

Purpose The prognostic significance of portal venous gas (PVG) in neonatal necrotizing enterocolitis (NEC) for operative intervention (OP), neonatal complications, and mortality remains uncertain. The authors designed a long-term prospective study to describe the natural history of PVG related to these outcomes and to test the hypothesis that PVG does not mandate OP. Methods All infants admitted to a single center between October 1991 and February 2003 were evaluated weekly to identify all cases of NEC (defined as Bell stage II or higher). Demographic, radiological, surgical, and outcome data were abstracted prospectively. Radiographic studies were performed at the onset of illness and at subsequent 6- to 8-hour intervals or as clinically indicated. A single pediatric radiologist reviewed all radiographs. Values are expressed as mean ± SD. Odds ratios and relative risk ratios are reported with 95% CIs. The level of significance was P ≤ .05. Results After the exclusion of 24 infants with lethal diseases, major congenital or chromosomal anomalies, or recurrent episodes of NEC, 194 of 5891 infants developed NEC. The overall incidence of NEC was 3.7%. In 194 infants with NEC, the incidence of PVG was 33% (n = 64). Gestational age (30.8 ± 4 vs 29.3 ± 4.2 weeks; P = .02) but not birth weight (1609 ± 761 vs 1434 ± 810 g; P = NS) was greater in infants with PVG compared with infants without PVG (n = 130). Sixty-six (34%) infants with NEC underwent OP. Operative intervention occurred more frequently in infants with PVG compared with infants without PVG (OR, 2.5; CI, 1.37-4.76; P = .003)—only 48% of infants with PVG underwent OP. Among the variables, gestational age, severe NEC (Bell stage III), severe intramural gas (in all 4 abdominal quadrants), and the presence of PVG, severe NEC was most highly associated with OP (OR, 77.47; CI, 10.36-580.16; P < .0001). Bell stage III NEC was present in 98% of infants who underwent OP compared with 40% of infants without OP ( P < .0001). Of all infants with NEC, 37 (19%) died. Mortality was higher among infants who underwent OP (33% vs 12%; P < .0003). A multivariate regression model identified Bell stage III (OR, 3.74; CI, 1.20-11.62; P = .02), but neither PVG nor OP, to be significantly associated with mortality. Of interest is that survival in infants with PVG was greater (but not significantly so) than in infants without PVG in both OP (74% vs 59%) and non-OP (91% vs 87%) groups. Furthermore, 30 of 64 (47%) infants with PVG survived without OP, and of all 33 infants with PVG who did not undergo OP, 30 (91%) infants survived. Conclusions Decision for OP should be based on the severity of NEC and not on the presence of PVG alone because nearly half of infants with PVG survive without OP. Overall, the presence of PVG does not increase the risk of mortality among infants with NEC. Severe NEC, but not OP, is associated with higher mortality.