Umbilical cord mesenchymal stem cell exosomes alleviate necrotizing enterocolitis in neonatal mice by regulating intestinal epithelial cells autophagy

BACKGROUND Necrotizing enterocolitis(NEC)is a severe gastrointestinal disease that affects premature infants.Although mounting evidence supports the therapeutic effect of exosomes on NEC,the underlying mechanisms remain unclear.AIM To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell(UCMSCs)exosomes,as well as their potential in alleviating NEC in neonatal mice.METHODS NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide(LPS),after which the mice received human UCMSC exosomes(hUCMSC-exos).The control mice were allowed to breastfeed with their dams.Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting.Colon tissues were collected from NEC neonates and analyzed by immunofluorescence.Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.RESULTS We found that autophagy is overactivated in intestinal epithelial cells during NEC,resulting in reduced expression of tight junction proteins and an increased inflammatory response.The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy.We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.CONCLUSION These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment.These findings also enhance our understanding of the role of the autophagy mechanism in NEC,offering potential avenues for identifying new therapeutic targets.

Efficacy of peritoneal drainage in very-low-birth-weight neonates with Bell’s stage II necrotizing enterocolitis:A single-center retrospective study

BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evaluate the clinical efficacy of peritoneal drainage in very-low-birth-weight(VLBW)neonates with modified Bell’s stage II NEC.METHODS This was a retrospective analysis of 102 NEC(modified Bell’s stage II)neonates born with VLBW who were treated at the Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)between January 2017 and January 2020;these included 24 cases in the peritoneal drainage group,36 cases in the exploratory laparotomy group,and 42 cases in the conservative treatment group.RESULTS The general characteristics were comparable in the three groups(P>0.05).Compared with conservative treatment,peritoneal drainage was associated with significantly shorter fasting time,abdominal distension relief time,fecal occult blood(OB)negative conversion time,and reduced hospital length of stay(HLOS)(P<0.05 for all).Despite some advantages of peritoneal drainage over conservative treatment in terms of cure,conversion to laparotomy,intestinal perforation,intestinal stenosis,and abdominal abscess rates,the differences were not statistically significant(P>0.05).Compared to exploratory laparotomy,the fecal OB negative conversion time was significantly shorter in the peritoneal drainage group(P<0.05);similarly,the exploratory laparotomy group showed longer fasting time,abdominal distension relief time,HLOS,and higher complication rate compared to peritoneal drainage group,but the between-group differences were not statistically significant(P>0.05).CONCLUSION Peritoneal drainage,an easy-to-operate procedure,can improve the clinical symptoms of VLBW neonates with Bell’s stage II NEC and help reduce the HLOS.

Necrotizing enterocolitis: A multifactorial disease with no cure

Necrotizing enterocolitis is an inflammatory bowel disease of neonates with significant morbidity and mortality in preterm infants. Due to the multifactorial nature o the disease and limitations in disease models, early diagnosis remains challenging and the pathogenesis elusive. Although preterm birth, hypoxic-ischemic events formula feeding, and abnormal bacteria colonization are established risk factors, the role of genetics and vasoactive/inflammatory mediators is unclear Consequently, treatments do not target the specific underlying disease processes and are symptomatic and surgically invasive. Breast-feeding is the most effective preventative measure. Recent advances in the prevention of necrotizing enterocolitis have focused on bioactive nutrients and trophic factors in human milk. Developmen of new disease models including the aspect of prematurity that consistently predisposes neonates to the disease with multiple risk factors will improve our understanding of the pathogenesis and lead to discovery of innovative therapeutics.

Role of LPS/CD14/TLR4-mediated inflammation in necrotizing enterocolitis:Pathogenesis and therapeutic implications

AIM:To establish the roles of lipopolysaccharide (LPS)/CD14/toll-like receptor 4 (TLR4)-mediated inflammation in a rat model of human necrotizing enterocolitis (NEC).METHODS: Six pairs of intestinal samples from human NEC were collected before and after recovery for histological and molecular analysis of inflammatory cytokines and signaling components. In the rat NEC model, we isolated 10-cm jejunum segments and divided them into six groups (n=6) for sham operation, treatment with LPS, bowel distension, combined bowel distension and LPS stimulation, and two therapeutic groups. The potential eff icacy of a recombinant CD18 peptide and a monoclonal CD14 antibody was evaluated in the latter two groups. The serum and tissue levels of several inflammatory mediators were quantified by real-time polymerase chain reaction, ELISA and immunoblotting.RESULTS: Human acute phase NEC tissues displayed significant increases (P<0.05) in levels of TLR4, CD14, myeloid differentiation protein (MD)-2, tumor necrosis factor (TNF)-α and nuclear factor-κB when compared to those after recovery. The histological and inflammatory picture of human NEC was reproduced in rats that were treated with combined bowel distension and LPS, but not in the sham-operated and other control rats. Serum levels of interleukin-6 and TNF-α were also elevated. The NEC pathology was attenuated by treating the NEC rats with a monoclonal CD14 antibody or an LPS-neutralizing peptide.CONCLUSION:LPS and distension are required to produce the histological and inflammatory features of NEC. A potential treatment option is blocking LPS activation and leukocyte infi ltration.

Application of prolonging small feeding volumes early in life to prevent of necrotizing enterocolitis in very low birth weight preterm infants

Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.

Mucin 1 and interleukin-11 protein expression and inflammatory reactions in the intestinal mucosa of necrotizing enterocolitis children after surgery

BACKGROUND Necrotizing enterocolitis(NEC)of the newborn is a frequently occurring clinical disease in infants.The mortality rate of NEC in premature infants is as high as 50%,and the morbidity rate is on the rise.NEC has already caused serious impacts on newborn survival and poses serious threats to both children and families.AIM To investigate the expression and significance of mucin 1(MUC1)and interleukin-11(IL-11)in the intestinal mucosa of infants with neonatal NEC after surgery.METHODS Forty-eight postoperative intestinal mucosal specimens from children with NEC(NEC group)and twenty-two intestinal mucosal specimens from children with congenital intestinal atresia(control group)were collected in our hospital.Immunohistochemical staining and Western blot analysis were used to examine the protein expression of MUC-1 and IL-11 in the two groups.The serum levels of tumor necrosis factor-α(TNF-α)and IL-1βin the two groups were measured by enzyme-linked immunosorbent assay,and the relationship between MUC-1 and IL-11 protein expression and serum TNF-αand IL-1βlevels was analyzed by the linear correlation method.RESULTS The protein expression of MUC-1 and IL-11 in the NEC group was significantly lower than that in the control group,and the difference was statistically significant(P<0.05).The levels of serum TNF-αand IL-1βin the NEC group were significantly higher than those in the control group(P<0.05).The protein expression of MUC-1 and IL-11 in the NEC group negatively correlated with serum TNF-αand IL-1βlevels(P<0.05).There was a significant negative correlation between the protein expression of MUC-1 and IL-11 and the levels of serum TNF-αand IL-1βin the NEC group.CONCLUSION The protein expression of MUC1 and IL-11 in the intestinal mucosa of children with NEC is significantly downregulated after surgery.This downregulation may be involved in the pathogenesis of this disease and has a certain correlation with inflammatory response factors in children with NEC.

Neonatal necrotizing enterocolitis caused by umbilical arterial catheter-associated abdominal aortic embolism:A case report

BACKGROUND Reports of necrotizing enterocolitis(NEC)caused by umbilical arterial catheter(UAC)-associated abdominal aortic embolism in neonates are rare.Herein,we report the case of an extremely low birth weight(ELBW)infant with NEC caused by UAC-associated abdominal aortic embolism.CASE SUMMARY A female infant,aged 21 min and weighing 830 g at 28+6 wk of gestational age,was referred to our hospital because of premature birth and shallow breathing.The patient was diagnosed with ELBW,neonatal respiratory distress syndrome,neonatal intrauterine infection,and neonatal asphyxia.Umbilical arterial and venous catheters were inserted on the day after birth and were removed 9 d later,according to the doctor’s plan.Within 48 h after extubation,the patient’s manifestations included poor responsiveness,heart rate range of 175-185/min,and currant jelly stool.Therefore,we considered a diagnosis of NEC.To determine the cause,we used B-mode ultrasound,which revealed a partial abdominal aortic embolism(2 cm×0.3 cm)and abdominal effusion.The patient was treated with nil per os,gastrointestinal decompression,anti-infective therapy,blood transfusion,and low-molecular-weight heparin sodium q12h for anticoagulant therapy(from May 20 to June 1,the dosage of low-molecular-weight heparin sodium was adjusted according to the anti-Xa activity during treatment).On the 67th day after admission,the patient fully recovered and was discharged.CONCLUSION The abdominal aortic thrombosis in this patient was considered to be catheter related,which requires immediate treatment once diagnosed.The choice of treatment should be determined according to the location of the thrombus and the patient’s condition.

Intestinal microbiome changes in an infant with right atrial isomerism and recurrent necrotizing enterocolitis:A case report and review of literature

BACKGROUND Necrotizing enterocolitis(NEC)is a multifactorial disease that predominantly affects premature neonates.Intestinal dysbiosis plays a critical role in NEC pathogenesis in premature neonates.The main risk factor for NEC in term infants is mesenteric hypoperfusion associated with ductaldependent congenital heart disease(CHD)that eventually leads to intestinal ischemia.The incidence of NEC in neonates with critical CHD is 6.8%-13%.However,the role of the intestinal microbiome in NEC pathogenesis in infants with ductal-dependent CHD remains unclear.CASE SUMMARY A male term neonate with right atrial isomerism underwent modified Blalock-Taussig shunt placement on the 14^(th)day of life and had persistent mesenteric hypoperfusion after surgery.The patient had episodes of NEC stageⅡA on the 1^(st)and 28^(th)days after cardiac surgery.Fecal microbial composition was analyzed before and after cardiac surgery by sequencing region V4 of the 16S rRNA gene.Before surgery,species belonging to genera Veillonella and Clostridia and class Gammaproteobacteria were detected,Bifidobacteriaceae showed a low abundance.The first NEC episode was associated with postoperative hemodynamic instability,intestinal ischemiareperfusion injury during cardiopulmonary bypass,and a high abundance of Clostridium paraputrificum(Clostridium sensu stricto I)(56.1%).Antibacterial therapy after the first NEC episode resulted in increased abundance of Gammaproteobacteria,decreased abundance of Firmicutes,and low alpha diversity.These changes in the microbial composition promoted the growth of Clostridium sensu strictoⅠ(72.0%)before the second NEC episode.CONCLUSION A high abundance of Clostridium sensu strictoⅠand mesenteric hypoperfusion may have contributed to NEC in the present case.

NLRP3 activation in macrophages promotes acute intestinal injury in neonatal necrotizing enterocolitis

Background Macrophages are involved in various immune inflammatory disease conditions.This study aimed to investigate the role and mechanism of macrophages in regulating acute intestinal injury in neonatal necrotizing enterocolitis(NEC).Methods CD68,nucleotide-binding oligomerization domain,leucine-rich repeat,and pyrin domain-containing 3(NLRP3),cysteine aspartate-specific protease-1(caspase-1),and interleukin-1β(IL-1β)in paraffin sections of intestinal tissues from NEC and control patients were detected with immunohistochemistry,immunofluorescence,and western blot.Hypertonic pet milk,hypoxia and cold stimulation were used to establish a mouse(wild type and Nlrp3^(-/-))model of NEC.The mouse macrophage(RAW 264.7)and rat intestinal epithelial cell-6 lines were also cultured followed by various treatments.Macrophages,intestinal epithelial cell injuries,and IL-1β release were determined.Results Compared to the gut“healthy”patients,the intestinal lamina propria of NEC patients had high macrophage infiltration and high NLRP3,caspase-1,and IL-1β levels.Furthermore,in vivo,the survival rate of Nlrp3^(-/-)NEC mice was dramatically improved,the proportion of intestinal macrophages was reduced,and intestinal injury was decreased compared to those of wild-type NEC mice.NLRP3,caspase-1,and IL-1β derived from macrophages or supernatant from cocultures of macrophages and intestinal epithelial cells also caused intestinal epithelial cell injuries.Conclusions Macrophage activation may be essential for NEC development.NLRP3/caspase-1/IL-1β cellular signals derived from macrophages may be the underlying mechanism of NEC development,and all these may be therapeutic targets for developing treatments for NEC.

Development of necrotizing enterocolitis after blood transfusion in very premature neonates

Background Prior studies report conflicting evidence on the association between packed red blood cell(PRBC)transfu-sions and necrotizing enterocolitis(NEC),especially in early weeks of life where transfusions are frequent and spontaneous intestinal perforation can mimic NEC.The primary objective of this study was to evaluate the association between PRBC transfusions and NEC after day of life(DOL)14 in very premature neonates.Methods A retrospective cohort analysis of very premature neonates was conducted to investigate association between PRBC transfusions and NEC after DOL 14.Primary endpoints were PRBC transfusions after DOL 14 until the date of NEC diagnosis,discharge,or death.Wilcoxon ranked-sum and Fisher's exact tests,Cox proportional hazards regression,and Kaplan-Meier curves were used to analyze data.Results Of 549 premature neonates,186(34%)received transfusions after DOL 14 and nine(2%)developed NEC(median DOL=38;interquartile range=32-46).Of the nine with NEC after DOL 14,all were previously transfused(P<0.001);therefore,hazard of NEC could not be estimated.Post hoc analysis of patients from DOL 10 onward included five additional patients who developed NEC between DOL 10 and DOL 14,and the hazard of NEC increased by a factor of nearly six after PRBC transfusion(hazard ratio=5.76,95%confidence interval=1.02-32.7;P=0.048).Conclusions Transfusions were strongly associated with NEC after DOL 14.Prospective studies are needed to determine if restrictive transfusion practices can decrease incidence of NEC after DOL 14.

Hepatoblastoma with neonatal necrotizing enterocolitis:Two case reports

We report two children with hepatoblastoma(HB)with a history of neonatal necrotizing enterocolitis(NEC).Case 1 was diagnosed with HB at 5 months of age.Liver enlargement was found during the NEC operation at 3 months of age and then was clinically diagnosed by imaging.After six chemotherapy courses,a partial hepatectomy was performed.Three months after ceasing the chemotherapy,a chest computed tomography scan suggested that distant metastasis of the tumor should be considered,and the lesion was removed.However,9 months after the operation,alpha-fetoprotein concentrations were increased,and abdominal imaging showed a recurrence of the tumor in situ,resulting in a hepatectomy.Case 2 was diagnosed with NEC shortly after birth and underwent an intestinal resection and anastomosis 1 month later.He was diagnosed with HB at 3 years of age.Hepatectomy was performed after five courses of chemotherapy.Chemotherapy was stopped after 10 courses,and alpha-fetoprotein concentrations were normal.At present,both children have survived and are in a healthy condition.Physicians should be aware of the possibility of HB and a history of NEC in children.Premature birth and low birth weight are common factors leading to the pathogenesis of HB and NEC.The association between these two diseases requires further study。

Intestinal microcirculatory dysfunction and neonatal necrotizing enterocolitis

Objective Based on the observation that coagulation necrosis occurs in the majority of neonatal necrotizing enterocolitis （NEC） patients, it is clear that intestinal ischemia is a contributing factor to the pathogenesis of NEC. However, the published studies regarding the role of intestinal ischemia in NEC are controversial. The aim of this paper is to review the current studies regarding intestinal microcirculatory dysfunction and NEC, and try to elucidate the exact role of intestinal microcirculatory dysfunction in NEC. Data sources The studies cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms used were ＂intestinal microcirculatory dysfunction＂ and ＂neonatal necrotizing enterocolitis＂. Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected. Results Immature regulatory control of mesentery circulation makes the neonatal intestinal microvasculature vulnerable. When neonates are subjected to stress, endothelial cell dysfunction occurs and results in vasoconstriction of arterioles, inflammatory cell infiltration and activation in venules, and endothelial barrier disruption in capillaries. The compromised vasculature increases circulation resistance and therefore decreases intestinal perfusion, and may eventually progress to intestinal necrosis. Conclusion Intestinal ischemia plays an important role through the whole course of NEC. New therapeutic agents targeting intestinal ischemia, like HB-EGF, are promising therapeutic agents for the treatment of NEC.

Bifidobacterium and Lactobacillus for preventing necrotizing enterocolitis in very-low-birth-weight preterm infants:a systematic review and meta-analysis

Background The therapeutic effect of Bifidobacterium and Lactobacillus on necrotizing enterocolitis(NEC)in very-low-birth-weight preterm infants was controversial,and we aimed to explore the exact impact of the two probiotics.Methods The PubMed,EMBASE,Web of Science and Cochrane Library were systematically searched for studies published from January 1,2010 to February 28,2019.Results were combined with fixed-effect model or random-effect model with specific conditions.Sensitivity analysis was conducted by the trim-and-fill method,and the Begger's and Egger's test were used to measure publication bias.Results The meta-analysis included 16 original articles with 4632 very-low-birth-weight preterm infants.With respect to the intervention of Bifidobacterium,we estimated non-significant decrease in the morbidity of NEC with a risk ratio(RR)of 0.75[95%confidence internal(CI)0.56-1.01,P=0.06].Regarding the effect of Lactobacillus,there was no evidence of significant lower risk in the incidence of NEC(RR=0.67,95%CI 0.39-1.17,P=0.16).The use of mixture of probiotics(Bifidobacterium and Lactobacillus)reduced the risk of NEC in the probiotics group(RR=0.45,95%CI 0.25-0.80,P=0.007).Conclusion The mixture of Bifidobacterium and Lactobacillus could prevent the morbidity of NEC in very-low-birth-weight preterm infants.But Bifidobacterium or Lactobacillus alone did not show this effect.

Predictive scores for mortality in full-term infants with necrotizing enterocolitis: experience of a tertiary hospital in Southwest China

Background: Although many risk factors for mortalityof necrotizing enterocolitis (NEC) were investigated,most of them were obtained from preterm infants, andfew works focused on the prognostic risk factors in fullterminfants. This study aimed to identify risk factors anddevelop a prediction score model for mortality in fulltermneonates with NEC.Methods: The risk factors were analyzed retrospectivelyby bivariate and multivariate logistic regression analysis in153 full-term neonates with NEC, who were hospitalizedin Children's Hospital of Chongqing Medical Universityfrom 2000 to 2013. A prediction score model was developedaccording to the regression coeffi cients of risk factors.Results: The mortality of the infants was 19.6%(30/153). The non-survivors had a younger age of diagnosisand advanced stage of NEC (P<0.05). They had a higherprevalence of respiratory failure, intestinal perforation,peritonitis and other complications, compared with thesurvivors (P<0.05). On the day of diagnosis, the nonsurvivorswere more likely to have abnormal laboratoryindicators than survivors (P<0.05). Age at diagnosis [oddsratio (OR)=0.91, 95% confidence interval (CI)=0.836-0.99], respiratory failure (OR=2.76, 95% CI=1.10-6.92),and peritonitis (OR=26.36, 95% CI=7.52-173.92) hadsignificant independent contributions to death. A scoremodel predicting death was developed, and the area underthe receiver operating characteristic curve was 0.869 (95%CI=0.803-0.935). All infants with scores ≥8 died.Conclusions: Younger age at diagnosis, peritonitis,and respiratory failure might be risk factors for themortality of full-term infants with NEC. Infants with apredictive score of 8 were at high risk for death.

Outcome in neonates with necrotizing enterocolitis and patent ductus arteriosus

Background:There is no agreement of the influence of patent ductus arteriosus(PDA)on outcomes in patients with necrotizing enterocolitis(NEC).In this study,we assessed the infl uence of PDA on NEC outcomes.Methods:A retrospective study of 131 infants with established NEC was performed.Outcomes(death,disease severity,need for surgery,hospitalization duration),as well as multiple clinical parameters were compared between NEC patients with no congenital heart disease(n=102)and those with isolated PDA(n=29).Univariate,multivariate and stepwise logistic regression analyses were performed.Results:Birth weight and gestational age were significantly lower in patients with PDA[median(95%CI):1120 g(1009-1562 g),28.4 wk(27.8-30.5 wk)]than in those without PDA[median(95%CI):1580 g(1593-1905 g),32.4 wk(31.8-33.5 wk);P<0.05].The risk of NEC-attributable fatality was higher in NEC patients with PDA(35%)than in NEC patients without PDA(14%)[univariate odds ratio(OR)=3.3,95%CI:1.8-8.6,P<0.05;multivariate OR=2.4,95%CI:0.82-2.39,P=0.111].Significant independent predictors for nonsurvival within the entire cohort were advanced disease severity stage III(OR=27.9,95%CI:7.4-105,P<0.001)and birth weight below 1100 g(OR=5.7,95%CI:1.7-19.4,P<0.01).Conclusions:In patients with NEC,the presence of PDA is associated with an increased risk of death.However,when important differences between the two study groups are controlled,only birth weight and disease severity may independently predict mortality.

Clinical signifi cance of FABP2 expression in newborns with necrotizing enterocolitis

Background: This meta-analysis aimed to determinethe role of human fatty acid binding protein 2 (FABP2)expression in the diagnosis of necrotizing enterocolitis(NEC) of newborns.Data sources: Eligible studies for further statisticalanalysis were identified from various databases including PubMed, Expert Medica Database, Web of Science,Cochrane Library, Google Scholar, China BioMedicineand China National Knowledge Infrastructure. Randomeffects model was used, and summary standardized meandifference (SMD) with its 95% confi dence interval (CI) wascalculated to assess the association of FABP2 expressionand NEC.Results: Ten articles which included 572 infants (262infants with NEC and 310 healthy controls) were includedin the current meta-analysis. FABP2 showed a positiverelationship with NEC of newborns (SMD=2.88, 95%CI=2.09-3.67, P<0.001). And FABP2 expression washigher in patients with advanced stage of NEC (stage IIIor stage II+III) than in those with early stage of NEC(stage I) (SMD=-0.48, 95% CI=-0.87 to -0.09, P=0.015).Ethnicity-stratifi ed analysis yielded signifi cantly differentestimates with a high FABP2 expression in NEC in bothCaucasians (SMD=3.16, 95% CI=1.90-4.43, P<0.001) andAsians (SMD=2.57, 95% CI=1.50-3.64, P<0.001). Samplebasedsubgroup analysis showed that FABP2 expressionwas positively correlated with neonatal NEC in bothurinary- and blood-sample subgroups (all P<0.05).Conclusion: The results prove that the high FABP2expression is related to the damage to intestinal cells,which may be a possible early detection marker identifyingneonatal NEC.

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

AIM： TO investigate the dynamic change and role of neuronal nitric oxide synthase （nNOS） and inducible nitric oxide synthase （iNOS） in neonatal rat with intestinal injury and to define whether necrotizing enterocolitis （NEC） is associated with the levels of nitric oxide synthase （NOS） in the mucosa of the affected intestine tissue. METHODS： Wistar rats less than 24 h in age received an intraperitoneal injection with 5 mg/kg lipopolysaccharide （LPS）. Ileum tissues were collected at 1, 3, 6, 12 and 24 h following LPS challenge for histological evaluation of NEC and for measurements of nNOS and iNOS. The correlation between the degree of intestinal injury and levels of NOS was determined. RESULTS： The LPS-injected increase in injury scores pups showed a significant versus the control. The expression of nNOS protein and mRNA was diminished after LPS injection. There was a negative significant correlation between the nNOS protein and the grade of median intestinal injury within 24 h. The expression of iNOS protein and mRNA was significantly increased in the peak of intestinal injury. CONCLUSION： nNOS and iNOS play different roles in LPS-induced intestinal injury. Caution should be exerted concerning potential therapeutic uses of NOS inhibitors in NEC.

Recent advances in small bowel diseases:Part Ⅰ

As is the case in all parts of gastroenterology and hepatology,there have been many advances in our knowledge and understanding of small intestinal diseases.Over 1000 publications were reviewed for 2008 and 2009,and the important advances in basic science as well as clinical applications were considered.In Part Ⅰ of this Editorial Review,seven topics are considered:intestinal development;proliferation and repair;intestinal permeability;microbiotica,infectious diarrhea and probiotics;diarrhea;salt and water absorption;necrotizing enterocolitis;and immunology/allergy.These topics were chosen because of their importance to the practicing physician.

Systemic changes and adverse effects induced by retinopathy of prematurity screening

AIM: To estimate the potential systemic events during and after retinopathy of prematurity (ROP) screening. ' METHODS: A prospective and descriptive designed study was conducted to detect the physiologic and pathological changes 24h before, during, and 72h after ROP screening. Control blood pressure (BP), saturation, pulse rate, and body temperature were routinely taken at various time internals before and after screening. Adverse effects pertain to cardiovascular system, respiratory system, gastric system, urinary system and nervous system were retrospect 0-72h after ROP screening at a 24-hour interval. RESULTS: Totally 1254 prematurity babies receiving ROP screening during Jan. 1st 2013 to Dec. 31th 2013 were enrolled in our survey. Compared to control vital sign data taken before the examination, there was a fluctuation in the diastolic BP with the increased 3.03 mm Hg (P=0.04) after 3 doses of mydriatic drops. Immediately after the examination, there was a further 12.64 mm Hg (P<0.01) increase in systolic BP and a 7.24 mm Hg (P<0.01) in diastolic BP. The mean pulse rate during examination was 22.4 bpm (P<0.01) higher than the 133.3 +/- 9.0 bpm control level. The oxygen saturation shared an average drop of 5% (P<0.01) during screening. In prematurity with postconceptional age less than 31wk, the incidence of apnea (23.5%), necrotizing enterocolitis (NEC) (8.7%), gastric residual (25.4%) and upper digestive tract hemorrhage (6.4%) also demonstrated a significant rise (P<0.01). CONCLUSION: In our study sample, ROP screening was associated with NEC, gastric residual and upper digestive tract hemorrhage. These gastrointestinal side effects, along with breath activity pattern change and vital signs indicators fluctuation, may be results of additional stress responses.

Dynamic change of epidermal growth factor in neonatal rat with intestine injury

AIM: To determine whether diminished levels of epidermal growth factor (EGF) were present in neo-natal rats with intestinal injury and related with the degree of intestinal injury, so we modeled a model in neo-natal rats of intestinal injury and to examine the dynamic levels of EGF on injury of intestine.METHODS: One-day-old Wistar rat pups received an intraperitoneally injection with 4 mg/kg lipopolysaccharide (LPS), followed by collection of ileum tissue at 1, 3, 6, 12,and 24 h following LPS administration. The ileum was for histological evaluation of NEC and for measurements of EGF using ABC-ELISA. The correlation between the degree of intestinal injury and levels of EGF was determined. RESULTS: The LPS-injected pups also showed a significant increase in injury scores at 1, 3, 6, 12, and 24 h [respectively, (1.08±0.61), (1.63±0.84), (1.95±0.72), (2.42±0.43)and (2.21±0.53)] vsthe control (0.12±0.17) (P＜0.01).EGF levels at 1, 3, 6, 12 h [respectively, (245.6±49.0), (221.4±39.0), (223.4±48.1), (246.0±46.6)] pg/mg were significantly loss than the control (275.6±50.4) pg/mg (P＜0.05). There was a significant negative correlation between the EGF levels and the grade of intestinal injury within 24 h (P＜0.05).CONCLUSION: Neo-natal rats with intestinal injury have significantly lower levels of ileum EGF. Reduced levels of this growth factor might be related to the pathogenesis of NEC.