Inequities in the Diagnosis of Pediatric Appendicitis in Tertiary Children's Hospitals and the Consequences of Delayed Diagnosis.

INTRODUCTION: Missed diagnosis (MD) of acute appendicitis is associated with increased risk of appendiceal perforation. This study aimed to investigate whether racial/ethnic disparities exist in the diagnosis of pediatric appendicitis by comparing rates of MD versus single-encounter diagnosis (SED) between racial/ethnic groups. METHODS: Patients 0-18 y-old admitted for acute appendicitis from February 2017 to December 2021 were identified in the Pediatric Health Information System (PHIS). International Classification of Diseases, 10th Revision, Clinical Modification diagnosis codes for Emergency Department visits within 7 d prior to diagnosis were evaluated to determine whether the encounter represented MD. Generalized mixed models were used to assess the association between MD and patient characteristics. A similar model assessed independent predictors of perforation. RESULTS: 51,164 patients admitted for acute appendicitis were included; 50,239 (98.2%) had SED and 925 (1.8%) had MD. Compared to non-Hispanic White patients, patients of non-Hispanic Black (odds ratio 2.5, 95% confidence interval 2.0-3.1), Hispanic (2.1, 1.8-2.5), and other race/ethnicity (1.6, 1.2-2.1) had higher odds of MD. There was a significant interaction between race/ethnicity and imaging (P < 0.0001). Among patients with imaging, race/ethnicity was not significantly associated with MD. Among patients without imaging, there was an increase in strength of association between race/ethnicity and MD (non-Hispanic Black 3.6, 2.7-4.9; Hispanic 3.3, 2.6-4.1; other 2.0, 1.4-2.8). MD was associated with increased risk of perforation (2.5, 2.2-2.8). CONCLUSIONS: Minority children were more likely to have MD. Future efforts should aim to mitigate the risk of MD, including implementation of algorithms to standardize the workup of abdominal pain to reduce potential consequences of implicit bias.

Initial Laparotomy Versus Peritoneal Drainage in Extremely Low Birthweight Infants With Surgical Necrotizing Enterocolitis or Isolated Intestinal Perforation: A Multicenter Randomized Clinical Trial.

OBJECTIVE: The aim of this study was to determine which initial surgical treatment results in the lowest rate of death or neurodevelopmental impairment (NDI) in premature infants with necrotizing enterocolitis (NEC) or isolated intestinal perforation (IP). SUMMARY BACKGROUND DATA: The impact of initial laparotomy versus peritoneal drainage for NEC or IP on the rate of death or NDI in extremely low birth weight infants is unknown. METHODS: We conducted the largest feasible randomized trial in 20 US centers, comparing initial laparotomy versus peritoneal drainage. The primary outcome was a composite of death or NDI at 18 to 22 months corrected age, analyzed using prespecified frequentist and Bayesian approaches. RESULTS: Of 992 eligible infants, 310 were randomized and 96% had primary outcome assessed. Death or NDI occurred in 69% of infants in the laparotomy group versus 70% with drainage [adjusted relative risk (aRR) 1.0; 95% confidence interval (CI): 0.87-1.14]. A preplanned analysis identified an interaction between preoperative diagnosis and treatment group (P = 0.03). With a preoperative diagnosis of NEC, death or NDI occurred in 69% after laparotomy versus 85% with drainage (aRR 0.81; 95% CI: 0.64-1.04). The Bayesian posterior probability that laparotomy was beneficial (risk difference <0) for a preoperative diagnosis of NEC was 97%. For preoperative diagnosis of IP, death or NDI occurred in 69% after laparotomy versus 63% with drainage (aRR, 1.11; 95% CI: 0.95-1.31); Bayesian probability of benefit with laparotomy = 18%. CONCLUSIONS: There was no overall difference in death or NDI rates at 18 to 22 months corrected age between initial laparotomy versus drainage. However, the preoperative diagnosis of NEC or IP modified the impact of initial treatment.

Hope on the horizon: promising novel therapies for necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) remains among the most common and devastating diseases in neonates. Despite advances in neonatal clinical care, specific treatment strategies and diagnostic modalities remain lacking. As a result, morbidity and mortality remain high. Improved understanding of the pathogenesis of NEC has the potential for improved therapeutics. Some of the areas of research leading to promising discoveries include inhibition of Toll-like receptor signaling, modulation of vascular endothelial growth factor signal pathways, defining metabolomic alterations in NEC to discover potential biomarkers, probing for genetic predispositions to NEC susceptibility, determining mechanistic relations between anemia and NEC, and microflora modulation through the use of probiotics. All of these areas may represent novel promising approaches to the prevention and treatment of NEC. This review will focus on these current and possible therapeutic perspectives.

Stem cell therapy for preventing neonatal diseases in the 21st century: Current understanding and challenges.

Diseases of the preterm newborn such as bronchopulmonary dysplasia, necrotizing enterocolitis, cerebral palsy, and hypoxic-ischemic encephalopathy continue to be major causes of infant mortality and long-term morbidity. Effective therapies for the prevention or treatment for these conditions are still lacking as recent clinical trials have shown modest or no benefit. Stem cell therapy is rapidly emerging as a novel therapeutic tool for several neonatal diseases with encouraging pre-clinical results that hold promise for clinical translation. However, there are a number of unanswered questions and facets to the development of stem cell therapy as a clinical intervention. There is much work to be done to fully elucidate the mechanisms by which stem cell therapy is effective (e.g., anti-inflammatory versus pro-angiogenic), identifying important paracrine mediators, and determining the timing and type of therapy (e.g., cellular versus secretomes), as well as patient characteristics that are ideal. Importantly, the interaction between stem cell therapy and current, standard-of-care interventions is nearly completely unknown. In this review, we will focus predominantly on the use of mesenchymal stromal cells for neonatal diseases, highlighting the promises and challenges in clinical translation towards preventing neonatal diseases in the 21st century.

An enhanced Lactobacillus reuteri biofilm formulation that increases protection against experimental necrotizing enterocolitis.

One significant drawback of current probiotic therapy for the prevention of necrotizing enterocolitis (NEC) is the need for at least daily administration because of poor probiotic persistence after enteral administration, increasing the risk of the probiotic bacteria causing bacteremia or sepsis if the intestines are already compromised. We previously showed that the effectiveness of Lactobacillus reuteri ( Lr) in preventing NEC is enhanced when Lr is grown as a biofilm on the surface of dextranomer microspheres (DM). Here we sought to test the efficacy of Lr administration by manipulating the Lr biofilm state with the addition of biofilm-promoting substances (sucrose and maltose) to DM or by mutating the Lr gtfW gene (encoding an enzyme central to biofilm production). Using an animal model of NEC, we determined that Lr adhered to sucrose- or maltose-loaded DM significantly reduced histologic injury, improved host survival, decreased intestinal permeability, reduced intestinal inflammation, and altered the gut microbiome compared with Lr adhered to unloaded DM. These effects were abolished when DM or GtfW were absent from the Lr inoculum. This demonstrates that a single dose of Lr in its biofilm state decreases NEC incidence. Importantly, preloading DM with sucrose or maltose further enhances Lr protection against NEC in a GtfW-dependent fashion, demonstrating the tunability of the approach and the potential to use other cargos to enhance future probiotic formulations. NEW & NOTEWORTHY Previous clinical trials of probiotics to prevent necrotizing enterocolitis have had variable results. In these studies, probiotics were delivered in their planktonic, free-living form. We have developed a novel probiotic delivery system in which Lactobacillus reuteri (Lr) is delivered in its biofilm state. In a model of experimental necrotizing enterocolitis, this formulation significantly reduces intestinal inflammation and permeability, improves survival, and preserves the natural gut microflora compared with the administration of Lr in its free-living form.

Critical intestinal cells originate from the host in enteroid-derived tissue-engineered intestine.

BACKGROUND: Enteroid-derived tissue-engineered intestine (TEI) contains intestinal subepithelial myofibroblasts (ISEMFs) and smooth muscle cells (SMCs). However, these cell types are not present in the donor enteroids. We sought to determine the origin of these cell types and to quantify their importance in TEI development. MATERIALS AND METHODS: Crypts from pan-EGFP or LGR5-EGFP mice were used for enteroid culture and subsequent implantation for the production of TEI. TEI from pan-EGFP enteroids was labeled for smooth muscle alpha actin (SMA) to identify ISEMFs and SMCs and green fluorescent protein (GFP) to identify cells from pan-EGFP enteroids. Fluorescence in situ hybridization (FISH) for the Y chromosome was applied to TEI from male LGR5-EGFP enteroids implanted into female nonobese diabetic/severe combined immunodeficiency mice. To identify chemotactic effects of intestinal epithelium on ISEMFs, a Boyden chamber assay was performed. RESULTS: Immunofluorescence of TEI from pan-EGFP enteroids revealed GFP-positive epithelium with surrounding SMA positivity and no colocalization of the two. FISH of TEI from male LGR5-EGFP enteroids implanted into female nonobese diabetic/severe combined immunodeficiency mice revealed that only the epithelium was Y chromosome positive. Chemotactic assays demonstrated increased ISEMF migration in the presence of enteroids (983 ± 133) compared to that in the presence of either Matrigel alone (357 ± 36) or media alone (339 ± 24; P ≤ 0.05). CONCLUSIONS: Lack of GFP/SMA colocalization suggests that ISEMFs and SMCs are derived from host animals. This was confirmed by FISH which identified only epithelial cells as being male. All other cell types originated from host animals. The mechanism by which these cells are recruited is unknown; however, Boyden chamber assays indicate a direct chemotactic effect of intestinal epithelium on ISEMFs.

Heparin-binding EGF-like growth factor promotes neuronal nitric oxide synthase expression and protects the enteric nervous system after necrotizing enterocolitis.

BackgroundNeonatal necrotizing enterocolitis (NEC) is associated with alterations of the enteric nervous system (ENS), with loss of neuronal nitric oxide synthase (nNOS)-expressing neurons in the intestine. The aim of this study was to investigate the roles of heparin-binding EGF-like growth factor (HB-EGF) in neural stem cell (NSC) differentiation, nNOS expression, and effects on ENS integrity during experimental NEC.MethodsThe effects of HB-EGF on NSC differentiation and nNOS production were determined using cultured enteric NSCs. Myenteric neuronal subpopulations were examined in HB-EGF knockout mice. Rat pups were exposed to experimental NEC, and the effects of HB-EGF treatment on nNOS production and intestinal neuronal apoptosis were determined.ResultsHB-EGF promotes NSC differentiation, with increased nNOS production in differentiated neurons and glial cells. Moreover, loss of nNOS-expressing neurons in the myenteric plexus and impaired neurite outgrowth were associated with absence of the HB-EGF gene. In addition, administration of HB-EGF preserves nNOS expression in the myenteric plexus and reduces enteric neuronal apoptosis during experimental NEC.ConclusionHB-EGF promotes the differentiation of enteric NSCs into neurons in a nitric oxide (NO)-dependent manner, and protects the ENS from NEC-induced injury, providing new insights into potential therapeutic strategies for the treatment of NEC in the future.

Facilitating surgeon understanding of complex anatomy using a three-dimensional printed model.

BACKGROUND: 3-dimensional prints (3DP) anecdotally facilitate surgeon understanding of anatomy and decision-making. However, the actual benefit to surgeons or patients has not been quantified. This study investigates how surgeon understanding of complex anatomy is altered by a 3DP compared to computed tomography (CT) scan or CT + digital reconstruction (CT + DR). MATERIALS AND METHODS: Key anatomic features were segmented from a CT-abdomen/pelvis of pygopagus twins to build a DR and printed in color on a 3D printer. Pediatric surgery trainees and attendings (n = 21) were tested regarding anatomy identification and their understanding of point-to-point distances, scale, and shape. RESULTS: There was no difference between media regarding point-to-point distances. The 3DP led to an increased number of correct answers for questions of scale and shape compared to CT (P < 0.05). CT + DR performance was intermediate but not statistically different from 3DP or CT. Identification of anatomy was inconsistent between media; however, answers were significantly closer to correct when using the 3DP. Participants completed the test faster with the 3DP (6.6 ± 0.5 min) (P < 0.05) than with CT (18.9 ± 2.5 min) or CT + 3DR (14.9 ± 1.5 min). CONCLUSIONS: Although point-to-point measurements were not different, 3DP increased the understanding of shape, scale, and anatomy. It enabled understanding significantly faster than other media. In difficult surgical cases with complex anatomy and a need for efficient multidisciplinary coordination, 3D printed models should be considered for surgical planning.

Evaluating the efficacy of different types of stem cells in preserving gut barrier function in necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. Increased intestinal permeability is central to NEC development. We have shown that stem cells (SCs) can reduce the incidence and severity of NEC. Our current goal was to investigate the efficacy of four different types of SC in preservation of gut barrier function during NEC. MATERIALS AND METHODS: We compared (1) amniotic fluid-derived mesenchymal SC, (2) bone marrow-derived mesenchymal SC, (3) amniotic fluid-derived neural SC, and (4) enteric neural SC. Premature rat pups received an intraperitoneal injection of 2 × 106 SC or phosphate-buffered saline only and were then subjected to experimental NEC. Control pups were breastfed and not subjected to NEC. After 48 h, animals received a single enteral dose of fluorescein isothiocyanate -labeled dextran (FD70), were sacrificed 4 h later, and serum FD70 concentrations determined. RESULTS: Compared to breastfed, unstressed pups with intact gut barrier function and normal intestinal permeability (serum FD70 concentration 2.22 ± 0.271 µg/mL), untreated pups exposed to NEC had impaired barrier function with significantly increased permeability (18.6 ± 4.25 µg/mL, P = 0.047). Pups exposed to NEC but treated with SC had significantly reduced intestinal permeability: Amniotic fluid-derived mesenchymal SC (9.45 ± 1.36 µg/mL, P = 0.017), bone marrow-derived mesenchymal SC (6.73 ± 2.74 µg/mL, P = 0.049), amniotic fluid-derived neural SC (8.052 ± 1.31 µg/mL, P = 0.0496), and enteric neural SC (6.60 ± 1.46 µg/mL, P = 0.033). CONCLUSIONS: SCs improve gut barrier function in experimental NEC. Although all four types of SC reduce permeability equivalently, SC derived from amniotic fluid may be preferable due to availability at delivery and ease of culture, potentially enhancing clinical translation.

Delaying Appendectomy Does Not Lead to Higher Rates of Surgical Site Infections: A Multi-institutional Analysis of Children With Appendicitis.

OBJECTIVES: To investigate the association between time to appendectomy and the risk of surgical site infections (SSIs) in children with appendicitis across multiple NSQIP-Pediatrics institutions. BACKGROUND: Several recently published single institution retrospective studies have reported conflicting relationships between delaying appendectomy and the risk of increasing surgical site infections (SSI) in both children and adults. This study combines data from NSQIP-Pediatrics with institutional data to perform a multi-institutional analysis to examine the effects of delaying appendectomy on surgical site infections. METHODS: Data from NSQIP-Pediatrics between January 2010 and June 2012 for cases of appendectomy for appendicitis at 6 institutions (preoperative characteristics, time of operation, and postoperative occurrences) were combined with data from medical record review (length of symptoms; times of initial presentation, emergency department (ED) triage, and admission; and diagnosis as simple appendicitis (SA, acute) or complicated appendicitis (CA, gangrenous/ruptured)). Cochran-Armitage tests for trend and multivariable logistic regression models were used to evaluate associations between time to appendectomy and SSI. RESULTS: Of the 1338 patients included, 70% had SA and 30% had CA. Postoperative SSIs were more common in CA (5.7% vs 1.2%, P < 0.001). SSI rates did not differ significantly across hospitals (P = 0.17). Compared with patients who did not develop an SSI, patients who developed an SSI had similar times between ED triage and appendectomy (median (interquartile range) 11.5 hours (6.4-14.7) versus 9.7 hours (5.8-15.6, P = 0.36), and similar times from admission to appendectomy (5.5 hours (1.9-10.2) versus 4.3 hours (1.4-9.9), P = 0.36). Independent risk factors for SSI were CA (Odds Ratio (95% CI): 3.46 (1.48-8.10), P = 0.004), longer symptom duration (OR for a 10-hour increase: 1.05 (1.01-1.10), P = 0.02), and presence of sepsis/septic shock (2.70 (1.17-6.28), P = 0.02). CONCLUSIONS: A 16-hour delay from ED presentation or a 12-hour delay from hospital admission to appendectomy was not associated with an increased risk for SSI.

Production of tissue-engineered intestine from expanded enteroids.

BACKGROUND: Short bowel syndrome is a life-threatening condition with few solutions. Tissue-engineered intestine (TEI) is a potential treatment, but donor intestine is a limiting factor. Expanded epithelial surrogates termed enteroids may serve as a potential donor source. MATERIALS AND METHODS: To produce TEI from enteroids, crypts were harvested from mice and enteroid cultures established. Enteroids were seeded onto polymer scaffolds using Matrigel or culture medium and implanted in immunosuppressed mice for 4 wk. Histology was analyzed using Periodic acid-Schiff staining and immunofluorescence. Neomucosa was quantified using ImageJ software. To determine whether TEI could be produced from enteroids established from small intestinal biopsies, 2 × 2-mm pieces of jejunum were processed for enteroid culture, enteroids were expanded and seeded onto scaffolds, and scaffolds implanted for 4 wk. RESULTS: Enteroids in Matrigel produced TEI in 15 of 15 scaffolds, whereas enteroids in medium produced TEI in 9 of 15 scaffolds. Use of Matrigel led to more neomucosal surface area compared to media (10,520 ± 2905 µm versus 450 ± 127 µm, P < 0.05). Histologic examination confirmed the presence of crypts and blunted villi, normal intestinal epithelial lineages, intestinal subepithelial myofibroblasts, and smooth muscle cells. Crypts obtained from biopsies produced an average of 192 ± 71 enteroids. A single passage produced 685 ± 58 enteroids, which was adequate for scaffold seeding. TEI was produced in 8 of 9 scaffolds seeded with expanded enteroids. CONCLUSIONS: Enteroids can be obtained from minimal starting material, expanded ex vivo, and implanted to produce TEI. This method shows promise as a solution to the limited donor intestine available for TEI production in patients with short bowel syndrome.

Heparin-binding EGF-like growth factor and enteric neural stem cell transplantation in the prevention of experimental necrotizing enterocolitis in mice.

BACKGROUND: Necrotizing enterocolitis (NEC) is associated with loss of neurons and glial cells in the enteric nervous system (ENS). Our goal was to determine whether enteric neural stem cell (NSC) transplantation, in conjunction with heparin-binding epidermal growth factor-like growth factor (HB-EGF), could protect against experimental NEC. METHODS: In vitro, HB-EGF on NSC proliferation and migration, and the effects of receptors utilized by HB-EGF to exert these effects, were determined. In vivo, mouse pups were exposed to experimental NEC and treated with NSC alone, HB-EGF alone, NSC+HB-EGF, or HB-EGF overexpressing NSC. NSC engraftment and differentiation into neurons in the ENS, intestinal injury, intestinal permeability, and intestinal motility were determined. RESULTS: HB-EGF promoted NSC proliferation via ErbB-1 receptors and enhanced NSC migration via ErbB-1, ErbB-4, and Nardilysin receptors. HB-EGF significantly enhanced the engraftment of transplanted NSC into the ENS during NEC. NSC transplantation significantly reduced NEC incidence and improved gut barrier function and intestinal motility, and these effects were augmented by simultaneous administration of HB-EGF or by transplantation of HB-EGF overexpressing NSC. CONCLUSION: HB-EGF promotes NSC proliferation and migration. HB-EGF and NSC reduce intestinal injury and improve gut barrier function and intestinal motility in experimental NEC. Combined HB-EGF and NSC transplantation may represent a potential future therapy to prevent NEC.

M1 to M2 macrophage polarization in heparin-binding epidermal growth factor-like growth factor therapy for necrotizing enterocolitis.

BACKGROUND: Macrophages can be polarized into proinflammatory (M1) and anti-inflammatory (M2) subtypes. However, whether macrophage polarization plays a role in necrotizing enterocolitis (NEC) remains unknown. MATERIALS AND METHODS: Macrophages were derived from the THP-1 human monocyte cell line. Apoptosis of human fetal small intestinal epithelial FHs-74 cells was determined by Annexin V/propidium iodide flow cytometry and by Western blotting to detect cleaved caspase-3. The effect of heparin-binding epidermal growth factor-like growth factor (HB-EGF) on macrophage polarization was determined by flow cytometry with M1/M2 markers and real time polymerase chain reaction. In vivo, experimental NEC was induced in mouse pups by repeated exposure to hypoxia, hypothermia, and hypertonic feedings. Intestinal histologic sections were subjected to immunohistochemical staining for the detection of M1 and M2 macrophages. RESULTS: In vitro, FHs-74 cell apoptosis was increased after coculture with macrophages and lipopolysaccharide (LPS). This apoptosis was increased by exposure to M1-conditioned medium and suppressed by exposure to M2-conditioned medium. HB-EGF significantly decreased LPS-induced M1 polarization and promoted M2 polarization via signal transducers and activators of transcription 3 activation. Addition of HB-EGF to LPS-stimulated macrophages suppressed the proapoptotic effects of the macrophages on FHs-74 cells. In vivo, we found enhanced intestinal macrophage infiltration in pups subjected to NEC, most of which were M1 macrophages. HB-EGF treatment of pups subjected to experimental NEC significantly reduced M1 and increased M2 polarization and protected the intestines from NEC. CONCLUSIONS: M1 macrophages promote NEC by increasing intestinal epithelial apoptosis. HB-EGF protects the intestines from NEC by preventing M1 and promoting M2 polarization.

An unusual case of foreign body pulmonary embolus: case report and review of penetrating trauma at a pediatric trauma center.

PURPOSE: Penetrating thoracic trauma is relatively rare in the pediatric population. Embolization of foreign bodies from penetrating trauma is very uncommon. We present a case of a 6-year-old boy with a penetrating foreign body from a projectile dislodged from a lawn mower. Imaging demonstrated a foreign body that embolized to the left pulmonary artery, which was successfully treated non-operatively. METHODS: We reviewed the penetrating thoracic trauma patients in the trauma registry at our institution between 1/1/03 and 12/31/12. Data collected included demographic data, procedures performed, complications and outcome. RESULTS: Sixty-five patients were identified with a diagnosis of penetrating thoracic trauma. Fourteen of the patients had low velocity penetrating trauma and 51 had high velocity injuries. Patients with high velocity injuries were more likely to be older and less likely to be Caucasian. There were no statistically significant differences between patients with low vs. high velocity injuries regarding severity scores or length of stay. There were no statistically significant differences in procedures required between patients with low and high velocity injuries. CONCLUSIONS: Penetrating thoracic trauma is rare in children. The case presented here represents the only report of cardiac foreign body embolus we could identify in a pediatric patient.

Development and implementation of an electronic health record generated surgical handoff and rounding tool.

Electronic health records (EHR) have been adopted across the nation at tremendous effort and expense. The purpose of this study was to assess improvements in accuracy, efficiency, and patient safety for a high-volume pediatric surgical service with adoption of an EHR-generated handoff and rounding list. The quality and quantity of errors were compared pre- and post-EHR-based list implementation. A survey was used to determine time spent by team members using the two versions of the list. Perceived utility, safety, and quality of the list were reported. Serious safety events determined by the hospital were also compared for the two periods. The EHR-based list eliminated clerical errors while improving efficiency by automatically providing data such as vital signs. Survey respondents reported 43 min saved per week per team member, translating to 372 work hours of time saved annually for a single service. EHR-based list users reported higher satisfaction and perceived improvement in efficiency, accuracy, and safety. Serious safety events remained unchanged. In conclusion, creation of an EHR-based list to assist with daily handoffs, rounding, and patient management demonstrated improved accuracy, increased efficiency, and assisted in maintaining a high level of safety.

Effects of lipopolysaccharide-induced inflammation on the interstitial cells of Cajal.

Interstitial cells of Cajal (ICC) have recently been found to display phenotypic changes. The present study is designed to determine whether phenotypic changes occur in ICC associated with an inflammatory microenvironment and whether the ICC phenotype could be recovered after the discontinuation of inflammatory stimuli. Immunohistochemistry studies revealed that the functional ICC marker, c-kit, was markedly reduced in patients with Hirschsprung's disease (n = 34) compared with controls (n = 12), whereas another marker of ICC, CD34, was not altered significantly. Compared with the vehicle group (n = 6), intraperitoneal injection of lipopolysaccharide (LPS; 1.5 mg/kg) in mice (n = 6) significantly induced plasma tumor necrosis factor-alpha (TNF-α) levels as determined by enzyme-linked immunosorbent assay. Western blot and real-time polymerase chain reaction assessment further showed that LPS injection markedly suppressed intestinal c-kit protein and mRNA expression, which could be blocked by Toll-like receptor 4 (TLR4) deficiency (n = 6) rather than TLR2 deficiency (n = 6) and had no effects on CD34. Compared with the vehicle group (n = 6), intraperitoneal TNF-α (30 µg/kg) administration (n = 6) also significantly reduced intestinal c-kit protein and mRNA levels but not CD34 levels. However, the reduction of c-kit induced by TNF-α injection was not suppressed by TLR4 deficiency (n = 6). Intestinal c-kit protein and mRNA levels were markedly restored after the discontinuation of TNF-α administration for 7 days. Moreover, immunofluorescence analysis of primary ICC further confirmed that exposure to TNF-α for 24 h suppressed c-kit expression, which could be restored after discontinuation of TNF-α exposure. CD34 expression was not altered upon exposure to TNF-α. Thus, phenotypic changes in ICC occur in an inflammatory microenvironment in the gut and LPS, TLR4 and TNFα are crucial to this process.

Heparin-binding EGF-like growth factor (HB-EGF) promotes cell migration and adhesion via focal adhesion kinase.

BACKGROUND: Cell migration and adhesion are essential in intestinal epithelial wound healing and recovery from injury. Focal adhesion kinase (FAK) plays an important role in cell-extracellular matrix signal transduction. We have previously shown that heparin-binding EGF-like growth factor (HB-EGF) promotes intestinal epithelial cell (IEC) migration and adhesion in vitro. The present study was designed to determine whether FAK is involved in HB-EGF-induced IEC migration and adhesion. MATERIALS AND METHODS: A scrape wound healing model of rat IECs was used to examine the effect of HB-EGF on FAK-dependent cell migration in vitro. Immunofluorescence and Western blot analyses were performed to evaluate the effect of HB-EGF on the expression of phosphorylated FAK (p-FAK). Cell adhesion assays were performed to determine the role of FAK in HB-EGF-induced cell adhesion on fibronectin (FN). RESULTS: HB-EGF significantly increased healing after scrape wounding, an effect that was reversed in the presence of an FAK inhibitor 14 (both with P < 0.05). HB-EGF increased p-FAK expression and induced p-FAK redistribution and actin reorganization in migrating rat IECs. Cell adhesion and spreading on FN were significantly increased by HB-EGF (P < 0.05). FAK inhibitor 14 significantly inhibited both intrinsic and HB-EGF-induced cell adhesion and spreading on FN (both with P < 0.05). CONCLUSIONS: FAK phosphorylation and FAK-mediated signal transduction play essential roles in HB-EGF-mediated IEC migration and adhesion.

Heparin-binding EGF-like growth factor (HB-EGF) therapy for intestinal injury: Application and future prospects.

Throughout the past 20 years, we have been investigating the potential therapeutic roles of heparin-binding EGF-like growth factor (HB-EGF), a member of the epidermal growth factor family, in various models of intestinal injury including necrotizing enterocolitis (NEC), intestinal ischemia/reperfusion (I/R) injury, and hemorrhagic shock and resuscitation (HS/R). Our studies have demonstrated that HB-EGF acts as an effective mitogen, a restitution-inducing reagent, a cellular trophic factor, an anti-apoptotic protein and a vasodilator, via its effects on various cell types in the intestine. In the current paper, we have reviewed the application and therapeutic effects of HB-EGF in three classic animal models of intestinal injury, with particular emphasis on its protection of the intestines from NEC. Additionally, we have summarized the protective functions of HB-EGF on various target cells in the intestine. Lastly, we have provided a brief discussion focusing on the future development of HB-EGF clinical applications for the treatment of various forms of intestinal injury including NEC.

Challenges of Managing Type 3c Diabetes in the Context of Pancreatic Resection, Cancer and Trauma.

Type 3c diabetes mellitus (T3cDM), also known as pancreatogenic or pancreoprivic diabetes, is a specific type of DM that often develops as a result of diseases affecting the exocrine pancreas, exhibiting an array of hormonal and metabolic characteristics. Several pancreatic exocrine diseases and surgical procedures may cause T3cDM. Diagnosing T3cDM remains difficult as the disease characteristics frequently overlap with clinical presentations of type 1 DM (T1DM) or type 2 DM (T2DM). Managing T3cDM is likewise challenging due to numerous confounding metabolic dysfunctions, including pancreatic endocrine and exocrine insufficiencies and poor nutritional status. Treatment of pancreatic exocrine insufficiency is of paramount importance when managing patients with T3cDM. This review aims to consolidate the latest information on surgical etiologies of T3cDM, focusing on partial pancreatic resections, total pancreatectomy, pancreatic cancer and trauma.