Gut permeability in patients with acute pancreatitis

Exploring the Role of Gut Microbiota and Probiotics in Acute Pancreatitis: A Comprehensive Review

Acute pancreatitis (AP) is a common and potentially severe gastrointestinal condition characterized by acute inflammation of the pancreas. The pathophysiology of AP is multifactorial and intricate, involving a cascade of events that lead to pancreatic injury and systemic inflammation. The progression of AP is influenced by many factors, including genetic predispositions, environmental triggers, and immune dysregulation. Recent studies showed a critical involvement of the gut microbiota in shaping the immune response and modulating inflammatory processes during AP. This review aims to provide a comprehensive overview of the emerging role of gut microbiota and probiotics in AP. We analyzed the implication of gut microbiota in pathogenesis of AP and the modification during an acute attack. The primary goals of microbiome-based therapies, which include probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and enteral nutrition, are to alter the composition of the gut microbial community and the amount of metabolites derived from the microbiota. By resetting the entire flora or supplementing it with certain beneficial organisms and their byproducts, these therapeutic approaches aim to eradicate harmful microorganisms, reducing inflammation and avoiding bacterial translocation and the potential microbiota-based therapeutic target for AP from nutrition to pre- and probiotic supplementation to fecal transplantation.

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery

Background/Aims

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI.

Methods

Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay.

Results

The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups.

Conclusions

Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

Acute pancreatitis is characterized by generalized intestinal barrier dysfunction in early stage

BACKGROUND AND AIMS

The role of intestinal-barrier in acute pancreatitis(AP) is poorly understood. We aimed to assess structural and functional changes in the intestinal-barrier in patients with early AP (time from onset<2 weeks) and the effect of enteral nutrition on them.

METHODS

In this prospective observational study, patients with early AP not on enteral nutrition were compared with controls for baseline intestinal-permeability(lactulose: mannitol ratio(L:M)), endotoxinemia(serum IgM/IgG anti-endotoxin antibodies), bacterial-translocation(serum bacterial 16S rRNA) and duodenal epithelial tight-junction structure by immunohistochemistry(IHC) for tight-junction proteins(claudin-2,-3,-4, zonula occludens-1(ZO1), junctional adhesion molecule(JAM) and occludin) and electron microscopy. These parameters were reassessed after 2 weeks enteral feeding in a AP patients subset.

RESULTS

96 patients with AP(age: 38.0 ± 14.5 years; etiology: biliary[46.8%]/alcohol[39.6%]; severe:53.2%, mortality:11.4%) and 40 matched controls were recruited. Patients with AP had higher baseline intestinal permeability(median L:M 0.176(IQR 0.073-0.376) vs 0.049(0.024-0.075) in controls; p < 0.001) and more frequent bacteraemia(positive bacterial 16S rRNA in 24/48 AP vs 0/21 controls; p < 0.001) with trend towards higher serum endotoxinemia(median IgG anti-endotoxin 78(51.2-171.6) GMU/ml vs 51.2(26.16-79.2) in controls; p = 0.061). Claudin-2, claudin-3, ZO1 were downregulated in both duodenal crypts and villi while claudin-4 and JAM were downregulated in duodenal villi and crypts respectively. 22 AP patients reassessed after initiation of enteral nutrition showed trend towards improving intestinal permeability, serum endotoxinemia and bacteraemia, with significant improvement in claudin-2,-3 in duodenal villi.

CONCLUSION

Patients with AP have significant disturbances in intestinal barrier structure and function in first 2 weeks from onset that persist despite institution of enteral nutrition.

A self-powered ingestible wireless biosensing system for real-time in situ monitoring of gastrointestinal tract metabolites

Information related to the diverse and dynamic metabolite composition of the small intestine is crucial for the diagnosis and treatment of various diseases. However, our current understanding of the physiochemical dynamics of metabolic processes within the small intestine is limited due to the lack of in situ access to the intestinal environment. Here, we report a demonstration of a battery-free ingestible biosensing system for monitoring metabolites in the small intestine. As a proof of concept, we monitor the intestinal glucose dynamics on a porcine model. Battery-free operation is achieved through a self-powered glucose biofuel cell/biosensor integrated into a circuit that performs energy harvesting, biosensing, and wireless telemetry via a power-to-frequency conversion scheme using magnetic human body communication. Such long-term biochemical analysis could potentially provide critical information regarding the complex and dynamic small intestine metabolic profiles.

Interleukin-22 Attenuates Acute Pancreatitis-Associated Intestinal Mucosa Injury in Mice via STAT3 Activation

Background/Aims

Interleukin-22 (IL-22) is an important cytokine maintaining homeostasis at barrier surfaces. In this study, the role of IL-22 in acute pancreatitis-associated intestinal injury was further explored.

Methods

Severe acute pancreatitis (SAP) was induced by administration of L-arginine in Balb/c mice at different time gradients. Histopathological examinations were made in both the pancreas and small intestine. Furthermore, recombinant murine IL-22 (rIL-22) was administrated to L-arginine-induced SAP mice by intraperitoneal injection. The mRNA levels of IL-22R1, Reg-IIIβ, Reg-IIIγ, Bcl-2, and Bcl-xL were detected in the small intestine by real-time polymerase chain reaction, and protein levels of total and phosphorylated STAT3 were assessed via Western blot.

Results

Compared with normal control group, 72 hours of L-arginine exposure induced the most characteristic histopathological changes of SAP, evidenced by pathological changes and serum amylase levels. Meanwhile, significant pancreatitis-associated intestinal mucosa injury was also observed. The gene expression levels of antimicrobial proteins Reg-IIIβ, Reg-IIIγ and anti-apoptosis proteins Bcl-2, Bcl-xL were downregulated in small intestine. Furthermore, Larginine- induced SAP was attenuated by rIL-22 treatment. Importantly, pancreatitis-associated intestinal mucosa injury was also ameliorated, reflected by improved pathological changes and significant increase in gene expression levels of Reg-IIIβ, Reg-IIIγ, Bcl-2 and Bcl-xL. Consistently, serum amylase levels and mortality were decreased in mice treated with rIL-22. Mechanistically, the upregulated expressions of these protective genes were achieved by activating STAT3.

Conclusions

Exogenous rIL-22 attenuates L-arginine-induced acute pancreatitis and intestinal mucosa injury in mice, via activating STAT3 signaling pathway and enhancing the expression of antimicrobial peptides and antiapoptotic genes.

Mesenchymal stromal cell therapy for pancreatitis: Progress and challenges

Pancreatitis is a common gastrointestinal disease with no effective therapeutic options, particularly for cases of severe acute and chronic pancreatitis (CP). Mesenchymal stromal cells (MSCs) are multipotent cells with diverse biological properties, including directional migration, paracrine, immunosuppressive, and antiinflammatory effects, which are considered an ideal candidate cell type for repairing tissue damage caused by various pathogenies. Several researchers have reported significant therapeutic efficacy of MSCs in animal models of acute and CP. However, the specific underlying mechanisms are yet to be clarified and clinical application of MSCs as pancreatitis therapy has rarely been reported. This review mainly focuses on the potential and challenges in clinical application of MSCs for treatment of acute and CP, along with discussion of the underlying molecular mechanisms.

LincRNA-EPS alleviates severe acute pancreatitis by suppressing HMGB1-triggered inflammation in pancreatic macrophages

Acute pancreatitis (AP), an inflammatory disorder of the pancreas with a high hospitalization rate, frequently leads to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). However, therapeutic targets for effective treatment and early intervention of AP are still urgently required to be identified. Here, we have observed that the expression of pancreatic lincRNA-EPS, a long intergenic non-coding RNA, is dynamically changed during both caerulein-induced AP (Cer-AP) and sodium taurocholate-induced severe AP (NaTc-SAP). The expression pattern of lincRNA-EPS is negatively correlated with the typical inflammatory genes such as IL-6, IL-1β, CXCL1, and CXCL2. Further studies indicate that knockout of lincRNA-EPS aggravates the pathological symptoms of AP including more induction of serum amylase and lipase, severe edema, inflammatory cells infiltration and acinar necrosis in both experimental AP mouse models. Besides these intrapancreatic effects, lincRNA-EPS also protects against tissue damages in the extra-pancreatic organs such as lung, liver, and gut in the NaTc-SAP mouse model. In addition, we have observed more serum pro-inflammatory cytokines TNF-α and IL-6 in the lincRNA-EPS^-/- NaTc-SAP mice and more extracellular HMGB1 around injured acinar cells in the pancreas from lincRNA-EPS^-/- NaTc-SAP mice, compared with their respective controls. Pharmacological inhibition of NF- κ B activity by BAY11-7082 significantly abolishes the suppressive effect of lincRNA-EPS on TLR4 ligand-induced inflammatory genes in macrophages. Our study has described a protective role of lincRNA-EPS in alleviating AP and SAP, outlined a novel pathway that lincRNA-EPS suppresses HMGB1-NF- κ B-dependent inflammatory response in pancreatic macrophages and provided a potential therapeutic target for SAP.

Overexpression of miR-99a Alleviates Intestinal Mucosal Barrier Injury in Rats with Severe Acute Pancreatitis

Severe acute pancreatitis (SAP), which is characterized by acute onset and high mortality, is complicated with systemic inflammatory response syndrome. This study investigated the molecular mechanism underlying SAP-induced intestinal mucosal barrier injury. SAP was established in rats by retrograde injection of sodium taurocholate (STC) into biliopancreatic duct. Transfection of miR-99a mimic was conducted 24 h before the SAP establishment. Histological properties of pancreatic and intestinal tissues were observed by hematoxylin-eosin staining. The serum levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, procalcitonin (PCT), endotoxin (ET), and diamine oxidase (DAO) were measured by enzyme-linked immunosorbent assay. The expressions of miR-99a, NADPH oxidase (NOX)4, zonula occludens (ZO)-1, occludin, and claudin-1 in pancreatic and the intestinal tissue were determined by quantitative reverse transcription polymerase chain reaction or Western blot. STC injection damaged pancreatic and intestinal tissues of the rats. During the model construction, the serum levels of IL-1β, TNF-α, PCT, ET, and DAO were increased, whereas miR-99a expression in pancreatic and intestinal tissues of the rats was decreased. miR-99a mimic alleviated SAP-induced histological abnormality of pancreatic and intestinal tissues; moreover, it reversed the serum levels of IL-1β, TNF-α, PCT, ET, and DAO increased by SAP, decreased SAP-increased NOX4 expression and increased the expressions of ZO-1, occludin, and claudin-1 previously decreased by SAP in pancreatic and the intestinal tissues. Thus, overexpressed miR-99a could alleviate intestinal mucosal barrier injury in rats with SAP.

Percutaneous Gastrostomy in Necrotizing Pancreatitis: Friend or Foe?

BACKGROUND

Enteral nutrition plays a central role in managing necrotizing pancreatitis (NP). Although the nasojejunal (NJ) route is widely used, percutaneous gastrostomy (PEG-J) is an alternative technique that is also applied commonly. We hypothesized that NJ and PEG-J had similar morbidity in the setting of NP.

METHODS

All patients receiving preoperative enteral nutrition before surgical debridement for NP (2005-2015) were segregated into NJ or PEG-J.

RESULTS

A total of 242 patients had complete data for analysis (155 men/87 women; median age 54 years; 47% biliary and 16% alcohol-related pancreatitis). NJ was used exclusively in 187 patients (77%); 25 patients (10%) were fed exclusively by PEG-J; the remaining 30 patients (13%) had NJ first, followed by PEG-J. Equal proportions of NJ and PEG-J patients reached enteral feeding goal (67% vs. 68%, p ≈ 1) and increased serum albumin (39% vs. 36%, p = 0.87). No difference was seen in rate of pancreatic necrosis infection (NJ 53% vs. PEG-J 49%, p = 0.64). NJ patients had significantly more complications compared to PEG-J (51%vs.27%,p = 0.0015). However, NJ patients had more grade I/II complication, compared to PEG-J patients, who had more grade III/IV complication (Grade I/II: NJ 51%vs. PEG-J 16%; Grade III/IV NJ 0%vs. PEG-J 11%, p < 0.0001).

CONCLUSION

In necrotizing pancreatitis, NJ and PEG-J both delivered enteral nutrition effectively. Patients with NJ feeding had significantly more complications than those with PEG-J; however, NJ complications were less severe.

Analysis of Genetic Association of Intestinal Permeability in Healthy First-degree Relatives of Patients with Crohn's Disease

Excessive intestinal permeability or intestinal barrier dysfunction as measured by various assays has been observed in various diseases. However, little is known about the factors contributing to altered gut permeability in these diseases. Our objective was to determine the genetic determinants of altered gut permeability as measured by the lactulose mannitol fractional excretion ratio (LacMan ratio) in 1075 healthy first-degree relatives of patients with Crohn's disease (CD). In a targeted analysis of single nucleotide polymorphisms (SNPs) located in genes associated with intestinal barrier function related or not to inflammatory bowel disease, we did not find a significant association with intestinal permeability. In an untargeted genome-wide association analysis, the top 100 associations were located in 22 genomic loci, although they were not statistically significant after correction for multiple testing (raw P values [1.8 × 10-7 - 1.4 × 10-5]. The lowest P value was obtained for rs9616637 (22q13.33, C22orf34), for which the minor allele A was associated with a decreased LacMan ratio. These results suggest that host genetic background has limited contribution toward intestinal permeability. Despite this, our study is currently the largest of its kind assessing gut permeability in vivo. It remains possible that smaller genetic effect sizes on LacMan ratio are not detectable in this sized cohort. Larger studies are warranted to identify the potential genetic contribution to intestinal permeability.

Association of endotoxaemia & gut permeability with complications of acute pancreatitis: Secondary analysis of data

Background & objectives:

In acute pancreatitis (AP) gut barrier dysfunction is considered as an important predisposing factor leading to increased intestinal permeability (IP). In this study a pooled analysis of data published in our previous four studies on various aspects of gut permeability and endotoxaemia in patients with AP was attempted to find an association between increased IP and severity of disease and associated complications.

Methods:

This study was a pooled analysis of data of four previously published prospective studies on AP. Gut permeability, assessed by lactulose/mannitol excretion in urine and endotoxin core antibodies type IgG and IgM (EndoCab IgG and IgM) were measured on days zero and seven (D0 and D7) of admission. All patients received standard treatment of AP. We studied whether IgG and IgM anti-endotoxin titres and lactulose-mannitol ratio (LMR) at admission and D7 were associated with organ failure, infection and mortality.

Results:

The titres of anti-endotoxin IgG and IgM were lower in all patients of AP (n=204), both in mild AP (n=24) and severe AP (n=180) in the first week, compared to controls (n=15). There was no significant difference in serum IgG and IgM anti-endotoxin levels and LMR at baseline and at D7 among patients with organ failure, infection and mortality.

Interpretation & conclusions:

Our findings showed that serum IgG and IgM anti-endotoxin titres and LMR at admission and at day 7 were not associated with organ failure, infection, and death of patients with AP.

Gut Leakage of Fungal-Derived Inflammatory Mediators: Part of a Gut-Liver-Kidney Axis in Bacterial Sepsis

Sepsis is a life-threatening response to systemic infection. In addition to frank gastrointestinal (GI) rupture/puncture, sepsis can also be exacerbated by translocation of pathogen-associated molecular patterns (PAMPs) from the GI tract to the systemic circulation (gut origin of sepsis). In the human gut, Gram-negative bacteria and Candida albicans are abundant, along with their major PAMP components, endotoxin (LPS) and (1 → 3)-β-D-glucan (BG). Whereas the influence of LPS in bacterial sepsis has been studied extensively, exploration of the role of BG in bacterial sepsis is limited. Post-translocation, PAMPs enter the circulation through lymphatics and the portal vein, and are detoxified and then excreted via the liver and the kidney. Sepsis-induced liver and kidney injury might therefore affect the kinetics and increase circulating PAMPs. In this article, we discuss the current knowledge of the impact of PAMPs from both gut mycobiota and microbiota, including epithelial barrier function and the "gut-liver-kidney axis," on bacterial sepsis severity.

MiRNA-155 Regulates the Th17/Treg Ratio by Targeting SOCS1 in Severe Acute Pancreatitis

Acute pancreatitis (AP) is a serious condition associated with intestinal barrier disruption or inflammation of the pancreatic tissue. Specific microRNAs are involved in the pathogenesis of AP, during which IL-17-producing CD4⁺ T helper (Th17) cells accumulate in the pancreas. In this study, significantly increased levels of miR-155 were detected in clinical samples from patients with AP, and overexpression of miR-155 correlated with severe AP (SAP). To identify the effect of miR-155 on T cell differentiation, we isolated CD4⁺ T lymphocytes and in vitro experiments showed that inhibition of miR-155 significantly reversed the stress-induced increase in the Th17/Treg ratio. The results also showed that miR-155 increased the Th17-mediated inflammatory response by targeting SOCS1. The interaction between miR-155 and the 3^′-UTR of SOCS1 was confirmed by a dual luciferase reporter assay and RT-PCR. Experimental AP of varying severity was induced in BALB/c mice by caerulein hyperstimulation and miR-155 expression was found to increase with disease progression. Inhibition of miR-155 expression significantly improved the pathology of the pancreas. We also observed downregulation of expression of inflammatory factors, IL-17, SOCS1 and phosphorylated STAT1 after miR-155 inhibition. In summary, miR-155 regulates the Th17/Treg ratio by targeting SOCS1, most probably via direct binding to its 3^′-UTR region, indicating that this microRNA may be a potential biomarker and/or therapeutic target for AP.

Nutritional Aspects of Acute Pancreatitis

The goal of nutritional support in acute pancreatitis is to reduce inflammation, prevent nutritional depletion, correct a negative nitrogen balance, and improve outcomes. Enteral nutrition (EN) in severe acute pancreatitis (SAP) should be preferred to parenteral nutrition. It maintains the integrity of the gut barrier, decreases intestinal permeability, downregulates the systemic inflammatory response, maintains intestinal microbiota equilibrium, and reduces the complications of the early phase of SAP, improving morbidity and possibly improving mortality, and it is less expensive. Further studies to understand optimal timing of nutrition, route of delivery of EN, and the type of nutrition and nutrients are necessary.

The role of the sensor kinase, QseC, an adrenergic receptor of Escherichia coli, in bacterial translocation during hemorrhagic shock

BACKGROUND

Hemorrhagic shock results in ileal mucosa damage and intestinal bacterial translocation. Additionally, during hemorrhagic shock, norepinephrine levels increase. Past research has shown that the QseC sensor kinase of Escherichia coli modulates the quorum-sensing response to epinephrine and norepinephrine. Therefore, the aim of our study was to examine whether the absence of the ability of E. coli to sense epinephrine/norepinephrine would attenuate the bacterial translocation to extraintestinal organs in a rat model of hemorrhagic shock.

METHODS

An E. coli MC1000 qseC mutant was constructed, and E. coli MC1000 and MC1000ΔqseC with streptomycin resistance were used to track bacterial translocation after gavage in rats. A rat model of nonlethal hemorrhagic shock was used. The rats were divided into six groups: controls (SS), rats that received a sham shock and MC1000 (M-SS), rats that received a sham shock and MC1000ΔqseC (Δ-SS), rats that received a hemorrhagic shock alone (HS), rats that received a hemorrhagic shock and MC1000 (M-HS), and rats that received a hemorrhagic shock and MC1000ΔqseC (Δ-HS).

RESULTS

We found the incidence of bacterial translocation in the M-HS rats was higher than in the Δ-HS rats. The observed effects seem to be largely dependent on the inability to sense epinephrine/norepinephrine and the decreased motility of E. coli MC1000ΔqseC.

CONCLUSION

Therefore, a role for E. coli sensing epinephrine/norepinephrine in the pathophysiology of bacterial translocation following hemorrhagic shock is proposed. The demonstration of such an effect would suggest a new mechanism for the development of shock-induced sepsis.

Dai-Huang-Fu-Zi-Tang alleviates pulmonary and intestinal injury with severe acute pancreatitis via regulating aquaporins in rats

BACKGROUND

Dai-Huang-Fu-Zi-Tang (DHFZT) is a famous traditional Chinese prescription with intestinal obstruction, acute pancreatitis and cholecystalgia for thousands of years. Our previous work found that DHFZT could act against pulmonary and intestinal pathological injury in rats with severe acute pancreatitis (SAP). But the underlying mechanism has not been fully elucidated. The aim of present study was to investigate whether DHFZT could relieve pulmonary and intestinal injury by regulating aquaporins after SAP induced by sodium taurocholate in rats.

METHODS

Forty of SD rats were used for dose dependant experiments of DHFZT.Accurate-mass Time-of-flight liquid chromatography-mass spectrometry was used for qualitative screening of chemical compositions of DHFZT. Twenty-four rats were randomly divided into 3 groups: sham group (n = 8), model group (SAP, n = 8), DHFZT group (SAP with DHFZT treatment, n = 8). SAP models were established by retrograde injections of 5% sodium taurocholate solutions into rat pancreaticobiliary ducts. Blood samples were taken at 0, 12, 24, 48 h post-operation for detecting serum amylase, lipase, endotoxin, TNF-α, IL-6 and IL-10. Protein expression and location of aquaporin (AQP)1, 5, 8 and 9 were assessed by immunohistochemistry, western blot and immunofluorescence respectively.

RESULTS

The study showed that 27 kinds of chemical composition were identified, including 10 kinds in positive ion mode and 17 kinds in negative ion mode. The results showed that AQP1, AQP5 of lung, and AQP1, AQP5, AQP8 of intestine in model group were significantly lower than that of sham group (P < 0.05), and which were obviously reversed by treatment with DHFZT. In addition, protein levels of pro-inflammatory cytokines such as TNF-α, IL-6 and endotoxin in peripheral blood were significantly suppressed by DHFZT, and that anti-inflammatory cytokine like IL-10 was just opposite. Finally, we also noted that DHFZT reduced serum levels of amylase, lipase and endotoxin, and also improved edema and pathological scores of lung and intestine after SAP.

CONCLUSIONS

DHFZT ameliorated the pulmonary and intestinal edema and injury induced by SAP via the upregulation of different AQPs in lung and intestine, and suppressed TNF-α, IL-6 expression and enhanced IL-10 expression.

Biliary tract external drainage protects against multiple organs injuries of severe acute pancreatitis rats via heme oxygenase-1 upregulation

OBJECTIVE

To investigate the effect of biliary tract external drainage (BTED) on severe acute pancreatitis (SAP) in rats and the relationship with heme oxygenase-1 (HO-1) pathway.

METHODS

Thirty SD rats weighing 250-300 g were randomly assigned into five groups (n = 6): sham surgery (SS) group, SAP group, SAP + BTED group, SAP + zinc protoporphyrin IX (ZnPP) group, SAP + BTED + ZnPP group. The SAP model was induced via retrograde injection of 4% sodium taurocholate (1 mL/kg) into biliopancreatic duct through duodenal wall. BTED was performed by inserting a cannula into the bile duct of SAP rats. Tissue and blood samples were collected 24 h after surgery. Pathological changes in organs were scored. The level of amylase, alanine transaminase (ALT), aspartate aminotransferase (AST), diamine oxidase (DAO), lipopolysaccharide (LPS), myeloperoxidase (MPO) and ability to inhibit hydroxyl radical(·OH) in serum were measured. The expression of hemeoxygenase-1 (HO-1), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in tissues were analyzed by RT- PCR and western-blot.

RESULTS

Organs damage in SAP rats was significantly alleviated by BTED (p < 0.05). Compared to the SAP group, the serum level of amylase, ALT, AST, DAO, MPO, and LPS were significantly lower in the SAP + BTED group, and the ability to inhibit ·OH was significantly higher (p < 0.05). The BETD treatment led to a significant reduction of TNF-α, IL-6 level and a significant increase of HO-1 level in tissues than in SAP rats (p < 0.05). ZnPP significantly inhibited all above mentioned changes.

CONCLUSIONS

BTED protected multiple organs against SAP related injuries via HO-1 upregulation.

Effect of ceramide-1-phosphate transfer protein on intestinal bacterial translocation in severe acute pancreatitis

BACKGROUND AND OBJECTIVE

The aim of the study was to investigate the effects of ceramide-1-phosphate transfer protein (CPTP) on the intestinal epithelial tight junction proteins in patients with severe acute pancreatitis (SAP).

METHODS

Fifty patients with SAP were classified into two groups according to the presence of bacterial translocation (BT) in the blood. Thirty healthy individuals were included in the control group. The presence of BT was analyzed by polymerase chain reaction. The expression of tight junction proteins and CPTP was determined using immunohistochemistry and western blotting.

RESULTS

Bacterial DNA was detected in the peripheral blood of 62.0% of the patients with SAP. The expression of CPTP and tight junction proteins in SAP patients was lower than that in healthy controls. Among the patients with SAP, those positive for BT(+) showed a lower level of CPTP and occluding (OC) and zonula occludens-1 (ZO-1) expression and a higher level of IVA cPLA2 expression than BT(-) patients. Moreover, the expression of CPTP was significantly associated with ZO-1 and showed a negative correlation with expression of IVA cPLA2 in SAP-BT(+) patients.

CONCLUSIONS

CPTP affects the expression of tight junction proteins and may protects the intestinal epithelial barrier by downregulating the expression of IVA cPLA2.

Autologous bone marrow stromal cell transplantation as a treatment for acute radiation enteritis induced by a moderate dose of radiation in dogs

Radiation enteritis is one of the most common complications of cancer radiotherapy, and the development of new and effective measures for its prevention and treatment is of great importance. Adult bone marrow stromal stem cells (ABMSCs) are capable of self-renewal and exhibit low immunogenicity. In this study, we investigated ABMSC transplantation as a treatment for acute radiation enteritis. We developed a dog model of acute radiation enteritis using abdominal intensity-modulated radiation therapy in a single X-ray dose of 14 Gy. ABMSCs were cultured in vitro, identified via immunofluorescence and flow cytometry, and double labeled with CM-Dil and superparamagnetic iron oxide (SPIO) before transplantation, which took place 48 hours after abdominal irradiation in a single fraction. The dog model of acute radiation enteritis was transplanted with cultured ABMSCs labeled with CM-Dil and SPIO into the mesenteric artery through the femoral artery. Compared with untreated control groups, dogs treated with ABMSCs exhibited substantially longer survival time and improved relief of clinical symptoms. ABMSC transplantation induced the regeneration of the intestinal epithelium and the recovery of intestinal function. Furthermore, ABMSC transplantation resulted in elevated serum levels of the anti-inflammatory cytokine interleukin-11 (IL10) and intestinal radioprotective factors, such as keratinocyte growth factor, basic fibroblast growth factor-2, and platelet-derived growth factor-B while reducing the serum level of the inflammatory cytokine IL17. ABMSCs induced the regeneration of the intestinal epithelium and regulated the secretion of serum cytokines and the expression of radioprotective proteins and thus could be beneficial in the development of novel and effective mitigators of and protectors against acute radiation enteritis.

Qing-Yi decoction in participants with severe acute pancreatitis: a randomized controlled trial

BACKGROUND

Qing-Yi Decoction (QYD) has been used for severe acute pancreatitis (SAP) patients in China for many years. There were two kinds of QYD: Num 1. QYD (QYD1) which is used in the acute response stage of SAP and Num 2. QYD (QYD2) which is used in the second stage of SAP. This study aims to evaluate the therapeutic efficacy of QYD in participants with SAP.

METHODS

In this prospective, randomized, double-blind, placebo-controlled trial, participants aged 18-70 years within the first 7 days after acute onset of typical abdominal pain (the definition of SAP was according to the 2007 Guidelines for Management of Severe Acute Pancreatitis in China) were selected. The disease severity was determined by the Ranson, Acute Physiology and Chronic Health Evaluation II, and Balthazar CT scores. The test group received Western medicine and Chinese medicine (Num.1 QYD and Num.2 QYD), while the control group received Western medicine and placebo. The primary end-points were length of hospital stay, total hospitalization expenses, operation rate, and mortality. The secondary end-points were organ complications (i.e., heart failure, respiratory failure, acute renal failure, and hepatic failure), duration of paralytic ileus, infection, intensive care unit stay, and respirator use.

RESULTS

From March 2008 to July 2010, a total of 300 participants with severe acute pancreatitis were assessed for eligibility in West China Hospital, and 100 were eligible for randomized allocation. Eighty-five participants (46 in the test group; 39 in the control group) were included in the statistical analyses. The two groups were similar in their baseline clinical characteristics (age, sex, and etiology) and disease severity. After the interventions, there were no differences between the two groups for length of hospital stay (P = 0.323), total hospitalization expenses (P = 0.252), operation rate (P = 0.231), mortality (P = 0.462), organ complications (P > 0.05), intensive care unit stay (P = 0.209), and respirator use (P > 0.05). However, the duration [median (interquartile range)] of paralytic ileus, i.e., 4 (2-6) days vs. 6 (4-8) days (P = 0.014) and rate of infection, i.e., (13.0 % vs. 35.9 %) (P = 0.013) differed significantly.

CONCLUSIONS

QYD could restore gastrointestinal motility to normal and reduce the infection rates in the SAP patients who completed a full course of QYD treatment according to per protocol analysis.

Arpin contributes to bacterial translocation and development of severe acute pancreatitis

AIM: To assess the impact of Arpin protein and tight junction (TJ) proteins in the intestinal mucosa on bacterial translocation in patients with severe acute pancreatitis (SAP).

METHODS: Fifty SAP patients were identified as study objects and then classified into two groups according to the presence of bacterial translocation (BT) in the blood [i.e., BT(+) and BT(-)]. Twenty healthy individuals were included in the control group. BT was analyzed by polymerase chain reaction, colonic mucosal tissue was obtained by endoscopy and the expression of TJ proteins and Arpin protein was determined using immunofluorescence and western blotting.

RESULTS: Bacterial DNA was detected in the peripheral blood of 62.0% of patients (31/50) with SAP. The expression of TJ proteins in SAP patients was lower than that in healthy controls. In contrast, Arpin protein expression in SAP patients was higher than in healthy controls (0.38 ± 0.19 vs 0.28 ± 0.16, P < 0.05). Among SAP patients, those positive for BT showed a higher level of claudin-2 expression (0.64 ± 0.27 vs 0.32 ± 0.21, P < 0.05) and a lower level of occludin (OC) (0.61 ± 0.28 vs 0.73 ± 0.32, P < 0.05) and zonula occludens-1 (0.42 ± 0.26 vs 0.58 ± 0.17, P = 0.038) expression in comparison with BT (-) patients. Moreover, the level of Arpin expression in BT (+) patients was higher than in BT (-) patients (0.61 ± 0.28 vs 0.31 ± 0.24, P < 0.05).

CONCLUSION: Arpin protein affects the expression of tight junction proteins and may have an impact on BT. These results contribute to a better understanding of the factors involved in bacterial translocation during acute pancreatitis.

Meta-analysis of gut barrier dysfunction in patients with acute pancreatitis

BACKGROUND

The gut is implicated in the pathogenesis of acute pancreatitis but there is discrepancy between individual studies regarding the prevalence of gut barrier dysfunction in patients with acute pancreatitis. The aim of this study was to determine the prevalence of gut barrier dysfunction in acute pancreatitis, the effect of different co-variables, and changes in gut barrier function associated with the use of various therapeutic modalities.

METHODS

A literature search was performed using PRISMA and MOOSE guidelines. Summary estimates were presented as pooled prevalence of gut barrier dysfunction and the associated 95 per cent c.i.

RESULTS

A total of 44 prospective clinical studies were included in the systematic review, of which 18 studies were subjected to meta-analysis. The pooled prevalence of gut barrier dysfunction was 59 (95 per cent c.i. 48 to 70) per cent; the prevalence was not significantly affected by disease severity, timing of assessment after hospital admission or type of test used, but showed a statistically significant association with age. Overall, nine of 13 randomized clinical trials reported a significant improvement in gut barrier function following intervention compared with the control group, but only three of six studies that used standard enteral nutrition reported a statistically significant improvement in gut barrier function after intervention.

CONCLUSION

Gut barrier dysfunction is present in three of five patients with acute pancreatitis, and the prevalence is affected by patient age but not by disease severity. Clinical studies are needed to evaluate the effect of enteral nutrition on gut function in acute pancreatitis.

Role of high mobility group box-1 and protection of growth hormone and somatostatin in severe acute pancreatitis

In this study, we investigated the potential role of high-mobility group box 1 (HMGB1) in severe acute pancreatitis (SAP) and the effects of growth hormone (G) and somatostatin (S) in SAP rats. The rats were randomly divided into 6 groups of 20 each: sham-operated, SAP, SAP+saline, SAP+G, SAP+S and SAP+G+S. Ileum and pancreas tissues of rats in each group were evaluated histologically. HMGB1 mRNA expression was measured by reverse transcription-PCR. Levels of circulating TNF-α, IL-1, IL-6, and endotoxin were also measured. In the SAP group, interstitial congestion and edema, inflammatory cell infiltration, and interstitial hemorrhage occurred in ileum and pancreas tissues. The levels of HMGB1, TNF-α, IL-1, IL-6 and endotoxin were significantly up-regulated in the SAP group compared with those in the sham-operated group, and the 7-day survival rate was 0%. In the SAP+G and SAP+S groups, the inflammatory response of the morphological structures was alleviated, the levels of HMGB1, TNF-α, IL-1, IL-6, and endotoxin were significantly decreased compared with those in the SAP group, and the survival rate was increased. Moreover, in the SAP+G+S group, all histological scores were significantly improved and the survival rate was significantly higher compared with the SAP group. In conclusion, HMGB1 might participate in pancreas and ileum injury in SAP. Growth hormone and somatostatin might play a therapeutic role in the inflammatory response of SAP.

Mesenchymal stem cells improve intestinal integrity during severe acute pancreatitis

Severe acute pancreatitis (SAP) is an acute inflammatory disease of the pancreas that involves various distant tissues and organs. This study aimed to investigate post-tissue injury repair by mesenchymal stem cells (MSCs) in a rat model of SAP. A total of 54 pathogen-free adult male SD rats were randomly assigned to the groups SAP, SAP + MSCs and sham-operated (SO). SAP was induced by 4% sodium taurocholate, and MSCs were injected via the dorsal penile vein 1 h later. The amylase activity, and tumor necrosis factor (TNF)-α and diamine oxidase (DAO) levels were measured with an enzyme-linked immunosorbent assay (ELISA), while the expression of aquaporin (AQP)-1 was evaluated by immunohistochemical staining. The pathological score of intestinal tissues was also compared among groups. Marked improvement in intestinal necrosis, villi shedding and infiltration of inflammatory cells was observed in the SAP + MSCs group compared to the SAP and SO groups. Amylase, TNF-α, and DAO levels were significantly increased in the SAP + MSCs group. The intestinal expression of AQP-1 was increased at 12 and 24 h post-MSC transplantation compared to the SO group. Rats of the SAP + MSCs group displayed higher pathological scores compared to the SAP group at all time points. Overall, these data showed that MSCs can inhibit systemic inflammation and reduce TNF-α release in a rat model of SAP-induced intestinal injury, suggesting that MSCs exert protective effects on the intestinal barrier during SAP.

Acute radiation enteritis caused by dose-dependent radiation exposure in dogs: experimental research

Accidental or intended radiation exposure in mass casualty settings presents a serious and on-going threat. The development of mitigating and treating agents requires appropriate animal models. Unfortunately, the majority of research on radiation enteritis in animals has lacked specific assessments and targeted therapy. Our study showed beagle dogs, treated by intensity-modulated radiation therapy (IMRT) for abdominal irradiation, were administered single X-ray doses of 8-30 Gy. The degree of intestinal tract injury for all of the animals after radiation exposure was evaluated with regard to clinical syndrome, endoscopic findings, histological features, and intestinal function. The range of single doses (8 Gy, 10-14 Gy, and 16-30 Gy) represented the degree of injury (mild, moderate, and severe, respectively). Acute radiation enteritis included clinical syndrome with fever, vomiting, diarrhea, hemafecia, and weight loss; typical endoscopic findings included edema, bleeding, mucosal abrasions, and ulcers; and intestinal biopsy results revealed mucosal necrosis, erosion, and loss, inflammatory cell infiltration, hemorrhage, and congestion. Changes in serum diamine oxides (DAOs) and d-xylose represented intestinal barrier function and absorption function, respectively, and correlated with the extent of damage (P < 0.05 and P < 0.05, respectively). We successfully developed a dog model of acute radiation enteritis, thus obtaining a relatively objective evaluation of intestinal tract injury based on clinical performance and laboratory examination. The method of assessment of the degree of intestinal tract injury after abdominal irradiation could be beneficial in the development of novel and effective therapeutic strategies for acute radiation enteritis.

Overexpressed miRNA-155 dysregulates intestinal epithelial apical junctional complex in severe acute pancreatitis

AIM: To investigate whether miRNA-155 (miR-155) dysregulates apical junctional complex (AJC) protein expression in experimental severe acute pancreatitis (SAP).

METHODS: Twenty-four male BALB/c mice were randomly assigned to two groups: the SAP group (n = 12) receiving sequential intraperitoneal injection of 50 µg/kg caerulein and 10 mg/kg lipopolysaccharide over 6 h, and the control group (n = 12) receiving intraperitoneal injection of normal saline. Animals were sacrificed 3 h following the last injection for collection of blood samples and pancreas and distal ileal segment specimens. Routine pancreas and intestine histology was used to assess SAP pathology and intestinal epithelial barrier damage. Levels of serum amylase, diamine oxidase (DAO), and tumor necrosis factor (TNF)-α were determined using commercial kits. Total RNA samples were isolated from intestinal epithelial specimens and reversely transcribed into cDNA. miR-155 and RhoA mRNA expression profiles were determined using quantitative real-time polymerase chain reaction. Target genes for miR-155 were predicted using the miRTarBase database, RNA22 and PicTar computational methods. Western blotting was performed to quantitate the protein expression levels of the target gene RhoA, as well as zonula occludens (ZO)-1 and E-cadherin, two AJC component proteins.

RESULTS: Intraperitoneal injection of caerulein and lipopolysaccharide successfully induced experimental acute pancreatic damage (SAP vs control, 10.0 ± 2.0 vs 3.2 ± 1.2, P < 0.01) and intestinal epithelial barrier damage (3.2 ± 0.7 vs 1.4 ± 0.7, P < 0.01). Levels of serum amylase (21.6 ± 5.1 U/mL vs 14.3 ± 4.2 U/mL, P < 0.01), DAO (21.4 ± 4.1 mg/mL vs 2.6 ± 0.8 mg/mL, P < 0.01), and TNF-α (61.0 ± 15.1 ng/mL vs 42.9 ± 13.9 ng/mL, P < 0.01) increased significantly in SAP mice compared to those in control mice. miR-155 was significantly overexpressed in SAP intestinal epithelia (1.94 ± 0.50 fold vs 1.03 ± 0.23 fold, P < 0.01), and RhoA gene containing three miR-155-specific binding sites in the three prime untranslated regions was one of the target genes for miR-155. RhoA (22.7 ± 5.8 folds vs 59.6 ± 11.6 folds, P < 0.01), ZO-1 (46 ± 18 folds vs 68 ± 19 folds, P < 0.01), and E-cadherin proteins (48 ± 15 folds vs 77 ± 18 folds, P < 0.01) were underexpressed in SAP intestinal epithelia although RhoA mRNA expression was not significantly changed in SAP (0.97 ± 0.18 folds vs 1.01 ± 0.17 folds, P > 0.05).

CONCLUSION: TNF-α-regulated miR-155 overexpression inhibits AJC component protein syntheses of ZO-1, and E-cadherin by downregulating post-transcriptional RhoA expression, and disrupts intestinal epithelial barrier in experimental SAP.

Bacteremia in patients with acute pancreatitis as revealed by 16S ribosomal RNA gene-based techniques*

OBJECTIVES

To define the characteristic of bacteremia in patients with acute pancreatitis and determine its possible association with the disease severity.

DESIGN

A prospective controlled study.

SETTING

ICU of Jinling Hospital, China.

PATIENTS

A total of 48 patients with mild or severe acute pancreatitis were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples of peripheral blood were collected from the patients at 4 or 5 and 9 or 10 days after acute pancreatitis was definitely diagnosed. Resulting DNA from the blood was analyzed using denaturing gradient gel electrophoresis, and separated fragments were sequenced for identification of bacterial species. Bacterial DNA was detected in peripheral blood from 68.8% of patients with acute pancreatitis, and more than half (60.4%) of the patients encountered polymicrobial flora. Translocated bacteria in patients with acute pancreatitis were primarily constituted of opportunistic pathogens derived from the gut, including Escherichia coli, Shigella flexneri, Enterobacteriaceae bacterium, Acinetobacter lwoffii, Bacillus coagulans, and Enterococcus faecium. The species of circulating bacteria shifted remarkably among the patients with different severity. The presence of the bacteremia correlated positively with the Acute Physiology and Chronic Health Evaluation-II scores of patients with acute pancreatitis (r = 0.7918, p < 0.0001).

CONCLUSIONS

This study provides a detailed description on the prevalence of bacteremia and characteristic of bacterial species in patients with acute pancreatitis. We demonstrate an association between the bacteremia and the disease severity, which enables us to better understand a potential role of bacterial translocation in the pathogenesis of septic complication in acute pancreatitis.

Nasogastric or nasojejunal feeding in predicted severe acute pancreatitis: a meta-analysis

INTRODUCTION

Enteral feeding can be given either through the nasogastric or the nasojejunal route. Studies have shown that nasojejunal tube placement is cumbersome and that nasogastric feeding is an effective means of providing enteral nutrition. However, the concern that nasogastric feeding increases the chance of aspiration pneumonitis and exacerbates acute pancreatitis by stimulating pancreatic secretion has prevented it being established as a standard of care. We aimed to evaluate the differences in safety and tolerance between nasogastric and nasojejunal feeding by assessing the impact of the two approaches on the incidence of mortality, tracheal aspiration, diarrhea, exacerbation of pain, and meeting the energy balance in patients with severe acute pancreatitis.

METHOD

We searched the electronic databases of the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE. We included prospective randomized controlled trials comparing nasogastric and nasojejunal feeding in patients with predicted severe acute pancreatitis. Two reviewers assessed the quality of each study and collected data independently. Disagreements were resolved by discussion among the two reviewers and any of the other authors of the paper. We performed a meta-analysis and reported summary estimates of outcomes as Risk Ratio (RR) with 95% confidence intervals (CIs).

RESULTS

We included three randomized controlled trials involving a total of 157 patients. The demographics of the patients in the nasogastric and nasojejunal feeding groups were comparable. There were no significant differences in the incidence of mortality (RR=0.69, 95% CI: 0.37 to 1.29, P=0.25); tracheal aspiration (RR=0.46, 95% CI: 0.14 to 1.53, P=0.20); diarrhea (RR=1.43, 95% CI: 0.59 to 3.45, P=0.43); exacerbation of pain (RR=0.94, 95% CI: 0.32 to 2.70, P=0.90); and meeting energy balance (RR=1.00, 95% CI: 0.92 to 1.09, P=0.97) between the two groups. Nasogastric feeding was not inferior to nasojejunal feeding.

CONCLUSIONS

Nasogastric feeding is safe and well tolerated compared with nasojejunal feeding. Study limitations included a small total sample size among others. More high-quality large-scale randomized controlled trials are needed to validate the use of nasogastric feeding instead of nasojejunal feeding.

The effect of intestinal permeability and endotoxemia on the prognosis of acute pancreatitis

BACKGROUND/AIMS

Early intestinal mucosal damage plays an important role in severe acute pancreatitis (AP). Previous studies have shown that intestinal permeability (IP), serum endotoxin and cytokines contribute to the early intestinal barrier dysfunction in AP. This study explored the predictive capacity of IP, endotoxemia and cytokines as prognostic indicators in AP patients.

METHODS

Eighty-seven AP patients were included in the study. The patients were classified into three groups according to the Balthazar computed tomography severity index (CTSI). We compared the biochemical parameters, including IP, serum endotoxin level and cytokine level among the three groups. The associations of IP with serum endotoxin, cytokines, CTSI, and other widely used biochemical parameters and scoring systems were also examined.

RESULTS

IP, serum endotoxin, interleukin (IL-6) and tumor necrosis factor (TNF)-α had a positive correlation with the CTSI of AP. Endotoxin, IL-6, TNF-α, CTSI, the Ranson/APACHE II score, the duration of hospital stay, complications and death significantly affect IP in the AP patients.

CONCLUSIONS

We believe that IP with subsidiary measurements of serum endotoxin, IL-6 and TNF-α may be reliable markers for predicting the prognosis of AP. Further studies that can restore and preserve gut barrier function in AP patients are warranted.

Glucagonlike peptide 2 protects intestinal barrier in severe acute pancreatitis through regulating intestinal epithelial cell proliferation and apoptosis

OBJECTIVE

To investigate the protective effect of glucagon-like peptide 2 (GLP-2) on intestinal barrier dysfunction in severe acute pancreatitis and to explore the putative mechanism of this effect.

METHODS

Thirty rats were randomly divided into 3 groups. Group 1 received sham operation. Severe acute pancreatitis was induced in group 2 and group 3 via retrograde injection of 3% sodium taurocholate to the pancreatic duct. Rats in group 3 were peritoneally injected with GLP-2. Intestinal barrier dysfunction was characterized by the histological measurements and concentration of plasma diamine oxidase. The tissue sections of ileum were collected for the detection of proliferating cell nuclear antigen protein and apoptosis.

RESULTS

Glucagon-like peptide 2 administration improved the ileal mucosal injury, which was also demonstrated by the histological score of ileal mucosa. The concentration of diamine oxidase was decreased in rats with acute pancreatitis treated with GLP-2. Acute pancreatitis-induced epithelial cell apoptosis was partly prevented by GLP-2. Immunohistochemical staining of proliferating cell nuclear antigen protein was increased in group 3 compared with that in group 2.

CONCLUSIONS

Results from this study suggest that GLP-2 has a protective effect on intestinal barrier dysfunction in rats with severe acute pancreatitis via mechanisms closely involving promotion of cell growth and inhibition of intestinal epithelial cell apoptosis.

Evaluation of early enteral feeding through nasogastric and nasojejunal tube in severe acute pancreatitis: a noninferiority randomized controlled trial

OBJECTIVE

This study aimed to determine the noninferiority of early enteral feeding through nasogastric (NG) compared to nasojejunal (NJ) route on infectious complications in patients with severe acute pancreatitis (SAP).

METHODS

Patients with SAP were fed via NG (candidate) or NJ (comparative) route. The primary outcome was the occurrence of any infectious complication in blood, pancreatic tissue, bile, or tracheal aspirate. Secondary end points were pain in refeeding, duration of hospital stay, intestinal permeability assessed by lactulose/mannitol excretion, and endotoxemia assessed by endotoxin core antibody types immunoglobulin G and M.

RESULTS

Seventy-eight patients were randomized to feeding by either the NG or the NJ route. During the hospital stay, the presence of any infectious complication in the NG and NJ groups was 23.1% and 35.9% (significantly different), respectively. The effect size of the difference of infectious complications was -12.8 (95% confidence interval, -29.6 to 4.0). The upper limit of the 95% confidence interval was 4.0 and was within the 5% limit set for noninferiority. The value of 8.0 for the number needed to treat implies that 8 patients should be treated with NG compared with the NJ group to prevent 1 patient from any of the infectious complications.

CONCLUSIONS

Early enteral feeding through NG was not inferior to NJ in patients with SAP. Infectious complications were within the noninferiority limit. Pain in refeeding, intestinal permeability, and endotoxemia were comparable in both groups.

Protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) can result in intestinal mucosal injury. This study aimed to demonstrate the protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with SAP.

METHODS

Liposomes containing clodronate or phosphate buffered saline (PBS) were prepared by the thin-film method. SAP models were prepared by a uniform injection of sodium taurocholate (2 mL/kg body weight) into the subcapsular space of the pancreas. Sprague-Dawley rats were randomly divided into a control group (C group), a SAP plus PBS-containing liposomes group (P group) and a SAP plus clodronate-containing liposomes group (T group). At 2 and 6 hours after the establishment of SAP models, 2 mL blood samples were taken from the superior mesenteric vein to measure the contents of serum TNF-alpha and IL-12. Pathological changes in the intestine and pancreas were observed using hematoxylin and eosin staining, while apoptosis was detected using TUNEL staining. In addition, the macrophage markers cluster of differentiation 68 (CD68) in the intestinal tissue was assessed with immunohistochemistry.

RESULTS

At the two time points, the levels of TNF-alpha and IL-12 in the P group were higher than those in the C group (P<0.05). Compared with the P group, the levels of TNF-alpha and IL-12 decreased in the T group (P<0.05). The pathological scores of the intestinal mucosa and pancreas in the T group were lower than those of the P group. In the T group, large numbers of TUNEL-positive cells were observed, but none or few in the C and P groups. The number of CD68-positive macrophages decreased in the T group.

CONCLUSIONS

Clodronate-containing liposomes have protective effects against intestinal mucosal injury in rats with SAP. The blockade of macrophages may provide a novel therapeutic strategy in SAP.

Vasoactive intestinal peptide promotes gut barrier function against severe acute pancreatitis

To explore the influence of vasoactive intestinal peptide (VIP) on the gut barrier function in severe acute pancreatitis (SAP). Fifty four SD rats were randomly divided into three groups: sham operated (SO) group, SAP group and VIP intervention group. Each group was further divided into three time points: 1, 6 and 12 h after operation with 6 rats for each treatment point. SAP models were induced by retrograde injection of 4% sodium taurocholate into the bili-pancreatic duct. VIP intervention group was made by 5 nmol VIP intraperitoneal injection within 5 min after SAP model successfully obtained. The VIP in plasma and intestinal homogenate were detected with ELISA. The endotoxin in plasma of all groups was also tested. The expression levels of TLR4, TNF-α, IL-6, and IL-10 in gut mucosa were measured by RT-PCR. Meanwhile intestinal samples were harvested for pathological examination. Compared to SO group, the VIP in plasma and intestinal homogenate of SAP group were significantly decreased at 1 h after induction, and then gradually increased to beyond the level of SO group at 12 h. The endotoxin of SAP group was continually increased. The mRNA levels of TLR4, TNF-α, IL-6, and IL-10 were also increased with obvious pathological injuries in the intestine. In the VIP group, endotoxin in plasma was obviously decreased compared to SAP group. The expressions of TNF-α, IL-6 mRNA were suppressed while IL-10mRNA was increased. The intestinal pathological injuries were also markedly alleviated. These results suggested that VIP had protective effects on SAP gut barrier function through inhibiting intestinal mucosal inflammatory responses.

Polymorphisms of beta defensins are associated with the risk of severe acute pancreatitis

AIMS

Bacterial translocation from the intestinal tract plays an important role in severe acute pancreatitis (AP). Human β-defensins are a family of antimicrobial peptides present at the mucosal surface. The aim of this study was to investigate the relevance of single nucleotide polymorphisms (SNPs) in the DEFB1 gene and copy number polymorphisms of the DEFB4 genes in AP.

METHODS

124 AP patients (30 with mild and 94 with severe disease) and 100 healthy controls were enrolled in the study. Three SNPs of the DEFB1 gene [G-20A (c.-20G→A), C-44G (c.-44C→G) and G-52A (c.-52G→A)] were genotyped by Custom TaqMan assay. The DEFB4 gene copy number was determined by means of a TaqMan real-time PCR assay.

RESULTS

Significantly higher frequencies of the AA genotype of G-20A (c.-20G→A) and the AA genotype of G-52A (c.-52G→A) were observed among the patients with severe AP (SAP) compared with the healthy controls (38 vs. 20 and 41 vs. 18%, respectively). The GG protective genotype of C-44G (c.-44C→G) SNP was much less frequent (1%) among the patients than among the controls (9%). A higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with SAP compared with the healthy controls (62 vs. 24%, respectively).

CONCLUSIONS

The variations in the genes encoding human β-defensin-1 and -2 may be associated with the risk of SAP. and IAP.

The intestinal fatty acid binding protein diagnosing gut dysfunction in acute pancreatitis: a pilot study

OBJECTIVES

To study the use of intestinal fatty acid binding protein (I-FABP) in diagnosing gut dysfunction in patients with acute pancreatitis (AP).

METHODS

Thirty-two patients with AP onset within 7 days were enrolled in our study. The severity of disease and the gut dysfunction were evaluated as follows: on admission, on the seventh day of disease attack, and on the third day after enteral nutrition. Serum levels of I-FABP, citrulline, and C-reactive protein (CRP) and the lactulose and mannitol absorption ratio in urine were measured in parallel.

RESULTS

The serum level of I-FABP increased on admission, and it was more pronounced in severe attacks. All patients had increased gut dysfunction score, serum level of CRP, and urine level of lactulose and mannitol absorption ratio with decreased serum level of citrulline. A positive correlation was found between the following pairs of measurement on admission: serum level of I-FABP and gut dysfunction score, serum level of I-FABP and Acute Physiology and Chronic Health Evaluation II score, I-FABP and serum level of CRP, and serum level of I-FABP and the length of ICU stay. A reverse correlation between the serum level of I-FABP and the serum level of citrulline was found.

CONCLUSIONS

The serum level of I-FABP can be used for assessing the gut dysfunction and disease severity of AP.

Acute lung injury and ARDS in acute pancreatitis: mechanisms and potential intervention

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in acute pancreatitis still represents a substantial problem, with a mortality rate in the range of 30%-40%. The present review evaluates underlying pathophysiological mechanisms in both ALI and ARDS and potential clinical implications. Several mediators and pathophysiological pathways are involved during the different phases of ALI and ARDS. The initial exudative phase is characterized by diffuse alveolar damage, microvascular injury and influx of inflammatory cells. This phase is followed by a fibro-proliferative phase with lung repair, type II pneumocyte hypoplasia and proliferation of fibroblasts. Proteases derived from polymorphonuclear neutrophils, various pro-inflammatory mediators, and phospholipases are all involved, among others. Contributing factors that promote pancreatitis-associated ALI may be found in the gut and mesenteric lymphatics. There is a lack of complete understanding of the underlying mechanisms, and by improving our knowledge, novel tools for prevention and intervention may be developed, thus contributing to improved outcome.

Acute pancreatitis at the beginning of the 21st century: the state of the art

Acute pancreatitis is an acute inflammatory disease of the pancreas which can lead to a systemic inflammatory response syndrome with significant morbidity and mortality in 20% of patients. Gallstones and alcohol consumption are the most frequent causes of pancreatitis in adults. The treatment of mild acute pancreatitis is conservative and supportive; however severe episodes characterized by necrosis of the pancreatic tissue may require surgical intervention. Advanced understanding of the pathology, and increased interest in assessment of disease severity are the cornerstones of future management strategies of this complex and heterogeneous disease in the 21st century.

Effect of Yiqi Tongfu Zhuyu decoction enema therapy on intestinal mucosal barrier function in patients with sepsis

AIM: To observe the effect of Yiqi Tongfu Zhuyu decoction enema therapy on the intestinal mucosal barrier function in patients with sepsis.

METHODS: Forty cases of sepsis were randomly divided into two groups: the treatment group (20 cases) and the control group (20 cases). Sensitive antibiotics, nutritional support, and mechanical ventilation were administered to both groups if necessary. Combined Yiqi Tongfu Zhuyu enema treatment was given to the treatment group twice a day while normal saline enema was given to the control group twice a day. Peripheral bacterial DNA fragment was determined before and after treatment with PCR, plasma D-lactic acid level was monitored by spectrophotomentry, and the urinary lactulose/mannitol (L/M) values were monitored by HPLC. Occurrence of acute respiratory distress syndrome (ARDS) and multiple organ dysfunction symdrome (MODS) was observed in patients with sepsis.

RESULTS: The D-lactate levels were significantly reduced in the treatment group after 7 and 14 d compared with the control group (6.04 ± 1.06 µg/L vs 8.83 ± 0.73 µg/L; 3.89 ± 0.86 µg/L vs 7.18 ± 0.90 µg/L, both P < 0.01). Urinary L/M level was significantly lowered 14 d after treatment (0.0499 vs 0.0709, P < 0.05). After treatment, the rate of bacterial DNA negative fragment of treatment group was obviously higher than the control group and ARDS and MODS incidence rate were significantly reduced (74.1% vs 33.3%; 17.6% vs 50%; 0% vs 22.2%, all P < 0.05).

CONCLUSION: Yiqi Tongfu Zhuyu enema therapy can improve the intestinal mucosa barrier function of the patients with sepsis, and reduce intestinal bacteria and endotoxin translocation, and ARDS/MODS incidence in patients with sepsis.

Acute pancreatitis at the beginning of the 21st century: The state of the art

Acute pancreatitis is an acute inflammatory disease of the pancreas which can lead to a systemic inflammatory response syndrome with significant morbidity and mortality in 20% of patients. Gallstones and alcohol consumption are the most frequent causes of pancreatitis in adults. The treatment of mild acute pancreatitis is conservative and supportive; however severe episodes characterized by necrosis of the pancreatic tissue may require surgical intervention. Advanced understanding of the pathology, and increased interest in assessment of disease severity are the cornerstones of future management strategies of this complex and heterogeneous disease in the 21st century.

Effects of gut barrier dysfunction and NF-kappaB activation on aggravating mechanism of severe acute pancreatitis

OBJECTIVE

To study the effects of gut-derived endotoxin translocation and NF-kappaB activation on the aggravating mechanism of severe acute pancreatitis (SAP) and of treatment with pyrrolidine dithiocarbamate (PDTC) on rats with SAP.

METHODS

SD rats were randomly divided into sham operation group (SO), SAP group, SAP + lipopolysaccharide(LPS) group, pyrrolidine dithiocarbamate (PDTC) treatment group and LPS group. Biochemical parameters and cytokines were examined in the serum. Multiple organs pathological slices were examined. Expression of NF-kappaB mRNA in the liver tissue was detected by RT-PCR. Activation of NF-kappaB by the method of streptomycin avidin-peroxidase (SP) and expression of NF-kappaB p65 protein and its binding activity were analyzed by Western blot and electrophoretic mobidity shift assay (EMSA).

RESULTS

Compared with sham operation group, the concentration of TNF-alpha, alanine aminotransferase (ALT), and diamine oxidase (DAO) in serum significantly increased in SAP + LPS group (P < 0.05). Pathological changes were markedly observed in tissues and the expression of NF-kappaB mRNA in the liver significantly increased (P < 0.05) also, the activation of NF-kappaB and binding activity of NF-kappaB p65 protein in the liver markedly increased (P < 0.01) in SAP + LPS group. Treatment with PDTC markedly reduced concentration of ALT, DAO and TNF-alpha, and the expression of NF-kappaB, and the pathologic scores, as well as significantly decreased the expression of NF-kappaB p65 protein.

CONCLUSION

The activation and overexpression of NF-kappaB may participate in the aggravating mechanism of SAP. Treatment with PDTC has a protective effect on multiple organs damage in SAP.

Advancement of intestinal function disorders in severe acute pancreatitis

Recent studies indicate that increased intestinal permeability and changes of intestinal mucosal immune function are very common in patients with severe acute pancreatitis (SAP). And they may be the main reasons for bacterial and endotoxin translocation, which are associated with secondary infection and multiorgan dysfunction syndrome in SAP. However, the accurate mechanism underlying the abnormality of intestinal mucosal immune dysfunction is not clarified, which deserves further study.

Treatment of acute pancreatitis: focus on medical care

Acute pancreatitis has an incidence of about 300 per 1 million individuals per year, of which 10-15% of patients develop the severe form of the disease. Novel management options, which have the potential to improve outcome, include initial proper fluid resuscitation, which maintains microcirculation and thereby potentially decreases ischaemia and reperfusion injury. The traditional treatment concept in acute pancreatitis, fasting and parenteral nutrition, has been challenged and early initiation of enteral feeding in severe pancreatitis and oral intake in mild acute pancreatitis is both feasible and provides some benefits. There are at present no data supporting immunonutritional supplements and probiotics should be avoided in patients with acute pancreatitis. There is also no evidence of any benefits provided by prophylactic antibacterials in patients with predicted severe acute pancreatitis. A variety of specific medical interventions have been investigated (e.g. intense blood glucose monitoring by insulin) but none has become clinically useful. Lessons can probably be learned from critical care in general, but studies are needed to verify these interventions in acute pancreatitis.

Early gut mucosal dysfunction in patients with acute pancreatitis

OBJECTIVES

A clinical study was made to test the hypothesis that gut mucosal damage happens and correlates with endotoxemia, systemic inflammation, severity of disease, septic complication, and outcome in acute pancreatitis (AP) patients.

METHODS

Patients were divided into 3 groups according to severity: grade 1 (n = 26, mild), grade 2 (n = 18, severe AP [SAP] without organ dysfunction), and grade 3 (n = 18, SAP with organ dysfunction). Twenty healthy volunteers were enrolled as control group. The intestinal lactulose and mannitol absorption ratio, d-xylose absorption, endotoxin, and tumor necrosis factor alpha were detected in parallel to clinical data collection.

RESULTS

Lactulose and mannitol absorption ratio increased in patients with AP, and the increase was more pronounced in SAP (grade 1: 0.044 +/- 0.017, grade 2: 0.39 +/- 0.16, grade 3: 0.48 +/- 0.22, control: 0.024 +/- 0.009; P < 0.01 between control and AP, P < 0.01 between mild and severe group). d-Xylose absorption decreased in pancreatitis groups (P < 0.01) especially in severe groups (P < 0.01 between mild and SAP). We also observed a significant positive correlation of mucosal permeability with endotoxin (r = 0.902, P < 0.001) and tumor necrosis factor alpha changes (r = 0.862, P < 0.001). The severity and septic complication in AP patients were different accompanied with severity of gut mucosal damage.

CONCLUSIONS

Intestinal mucosal function is injured in early phase of AP especially in patients with organ dysfunction, which may be a stimulus for development of multiple organ dysfunction and correlate with bad outcome in AP patients.

Acute pancreatitis severity is exacerbated by intestinal ischemia-reperfusion conditioned mesenteric lymph

OBJECTIVE

To determine the effect of intestinal ischemia-reperfusion (IIR) on acute pancreatitis (AP) and the role of mesenteric lymph.

SUMMARY BACKGROUND DATA

Intestinal ischemia is an early feature of AP and is related to the severity of disease. It is not known whether this contributes to the severity of AP or is a consequence.

METHODS

Two experiments are reported here using intravital microscopy and a rodent model of mild acute pancreatitis (intraductal 2.5% sodium taurocholate). In the first, rats had an episode of IIR during AP that was produced by temporary occlusion of the superior mesenteric artery (30 min or 3 x 10 min) followed by 2h reperfusion. In a second study rats with AP had an intravenous infusion of mesenteric lymph collected from donor rats that had been subjected to IIR. In both experiments the pancreatic erythrocyte velocity (EV), functional capillary density (FCD), leukocyte adherence (LA), histology and edema index were measured.

RESULTS

The addition of IIR to AP caused a decline in the pancreatic microcirculation greater than that of AP alone (EV 42% of baseline vs. 73% of baseline AP alone, FCD 43% vs 72%, LA 7 fold increase vs 4 fold increase). This caused an increased severity of AP as evidenced by 1.4-1.8 fold increase of pancreatic edema index and histologic injury respectively. A very similar exacerbation of microvascular failure and increased pancreatitis severity was then demonstrated by the intravenous infusion of IIR conditioned mesenteric lymph from donor animals.

CONCLUSIONS

Unidentified factors released into the mesenteric lymph following IIR injury are capable of exacerbating AP. This highlights an important role for the intestine in the pathophysiology of AP pathogenesis and identifies mesenteric lymph as a potential therapeutic target.

Influence of enteral versus parenteral nutrition on blood glucose control in acute pancreatitis: a systematic review

BACKGROUND & AIMS

There is increasing evidence that tight glucose control may reduce infectious complications and mortality in surgical critically ill patients. However, data regarding the influence of artificial nutrition on glycemic homeostasis are limited. Our aim was to review all randomized controlled trials on enteral versus parenteral nutrition in acute pancreatitis to determine whether the route of feeding can affect the glucose control in the setting of this disease.

METHODS

Relevant literature cited in three electronic databases (Cochrane Central Register of Controlled Trials, EMBASE and Medline) were systematically reviewed. A meta-analysis was carried out using a random-effects model.

RESULTS

Thirteen randomized controlled trials on enteral versus parenteral nutrition in acute pancreatitis were identified. Seven studies were excluded from analysis, leaving 6 trials in which a total of 264 non-diabetic patients with acute pancreatitis were treated. Intake of nutrients did not differ among enterally and parenterally fed patients in 5 of 6 randomized controlled trials. Enteral nutrition reduced the risk of hyperglycemia (relative risk 0.53; 95% confidence interval 0.29-0.98; p = 0.04) and insulin requirement (relative risk 0.41; 95% confidence interval 0.24-0.70; p = 0.001).

CONCLUSIONS

Enteral nutrition, when compared with parenteral nutrition, is associated with better blood glucose control in patients with acute pancreatitis.

Acute pancreatitis--from cellular signalling to complicated clinical course

Acute pancreatitis (AP) is a common disease that has a mild to moderate course in most cases. During the last decade, a change in diagnostic facilities as well as improved intensive care have influenced both morbidity and mortality in AP. Still, however, a number of controversies and unresolved questions remain regarding AP. These include prognostic factors and how these may be used to improve outcome, diagnostic possibilities, their indications and optimal timing, and the systemic inflammatory reaction (systemic inflammatory response syndrome--SIRS) and its effect on the concomitant course of the disease and potential development of organ failure. The role of the gut has been suggested to be important in severe AP, but has recently been somewhat questioned. Despite extensive research, pharmacological and medical intervention of proven clinical value is scarce. Various aspects on surgical interventions, including endoscopic sphincterotomy, cholecystectomy and necrosectomy, as regards indications and timing, will be reviewed. Last, but not least, are the management of late complications and long-term outcome for patients with especially severe AP.

Early nasogastric feeding in predicted severe acute pancreatitis: A clinical, randomized study

OBJECTIVE

To compare the efficacy and safety of early, nasogastric enteral nutrition (EN) with total parenteral nutrition (TPN) in patients with predicted severe acute pancreatitis (SAP).

SUMMARY BACKGROUND DATA

In SAP, the magnitude of the inflammatory response as well as increased intestinal permeability correlates with outcome. Enteral feeding has been suggested superior to parenteral feeding due to a proposed beneficial effect on the gut barrier.

METHODS

Fifty patients who met the inclusion criteria were randomized to TPN or EN groups. The nutritional regimen was started within 24 hours from admission and EN was provided through a nasogastric tube. The observation period was 10 days. Intestinal permeability was measured by excretion of polyethylene glycol (PEG) and concentrations of antiendotoxin core antibodies (Endocab). Interleukins (IL)-6 IL-8, and C-reactive protein (CRP) were used as markers of the systemic inflammatory response. Morbidity and feasibility of the nutritional route were evaluated by the frequency of complications, gastrointestinal symptoms, and abdominal pain.

RESULTS

PEG, Endocab, CRP, IL-6, APACHE II score, severity according to the Atlanta classification (22 patients), and gastrointestinal symptoms or abdominal pain did not significantly differ between the groups. The incidence of hyperglycemia was significantly higher in TPN patients (21 of 26 vs. 7 of 23; P < 0.001). Total complications (25 vs. 52; P = 0.04) and pulmonary complications (10 vs. 21; P = 0.04) were significantly more frequent in EN patients, although complications were diagnosed dominantly within the first 3 days.

CONCLUSION

In predicted SAP, nasogastric early EN was feasible and resulted in better control of blood glucose levels, although the overall early complication rate was higher in the EN group. No beneficial effects on intestinal permeability or the inflammatory response were seen by EN treatment.

Breakdown of intestinal mucosa via accelerated apoptosis increases intestinal permeability in experimental severe acute pancreatitis

BACKGROUND

Bacterial translocation plays an important role for infectious complications in severe acute pancreatitis (SAP). Breakdown of intestinal mucosal integrity may increase intestinal permeability and may be implicated in bacterial translocation. It is suggested that increase in intestinal permeability is correlated with the changes of tight junction and/or apoptosis in intestinal epithelial cells. The aim of this study was to investigate the changes of intestinal mucosa and its permeability in SAP.

METHODS

SAP was induced by injection of 3% sodium deoxycholate into the biliopancreatic ducts in rats. Permeability of intestinal wall was assayed ex vivo by measuring the leaked amount of FITC-dextran from the ileum pouch. Alteration of tight junction proteins such as zonula occludens (ZO)-1 and Occludin was evaluated by Western blotting and immunofluorescence staining. Apoptotic change of intestinal mucosa was detected by TUNEL staining and DNA fragmentation ELISA. In vitro, apoptosis-inducing effect of pancreatitis-associated ascitic fluid (PAAF) was examined using T84 cells. Integrity of monolayer cells was assessed by transepithelial electric resistance (TEER).

RESULTS

Permeability of ileum was significantly increased 6 h after induction of SAP. Blood endotoxin level was significantly elevated and bacterial translocation occurred 18 h after induction of SAP. Six hours after induction of SAP, expressions of ZO-1 and Occludin were not altered, but apoptosis of ileum mucosa was significantly accelerated. Addition of PAAF to T84 cells did not affect expressions of ZO-1 or Occludin, but significantly increased the apoptosis and significantly decreased TEER.

CONCLUSIONS

These results suggest that breakdown of intestinal mucosa via accelerated apoptosis may increase in intestinal permeability in SAP and that PAAF contains factor(s) that accelerates the apoptosis of intestinal epithelial cells.