Jakob B Axelsson

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.

Biological Functions of Iduronic Acid in Chondroitin/Dermatan Sulfate.

The presence of iduronic acid in chondroitin/dermatan sulfate changes the properties of the polysaccharides because it generates a more flexible chain with increased binding potentials. Iduronic acid in chondroitin/dermatan sulfate influences multiple cellular properties, such as migration, proliferation, differentiation, angiogenesis and the regulation of cytokine/growth factor activities. Under pathological conditions such as wound healing, inflammation and cancer, iduronic acid has diverse regulatory functions. Iduronic acid is formed by two epimerases (i.e. dermatan sulfate epimerase 1 and 2) that have different tissue distribution and properties. The role of iduronic acid in chondroitin/dermatan sulfate is highlighted by the vast changes in connective tissue features in patients with a new type of Ehler–Danlos syndrome: adducted thumb‐clubfoot syndrome. Future research aims to understand the roles of the two epimerases and their interplay with the sulfotransferases involved in chondroitin sulfate/dermatan sulfate biosynthesis. Furthermore, a better definition of chondroitin/dermatan sulfate functions using different knockout models is needed. In this review, we focus on the two enzymes responsible for iduronic acid formation, as well as the role of iduronic acid in health and disease.

Prevention of postoperative peritoneal adhesions: Effects of lysozyme, polylysine and polyglutamate versus hyaluronic acid

Objective. Intraperitoneal adhesions are an important cause of postoperative intestinal obstruction, abdominal discomfort and infertility. In the present study we hypothesized that a combination of polypeptides with different surface properties, resulting in fine disperse low-soluble complexes, could be of benefit in the prevention of abdominal adhesions.Material and methods. Various polypeptides including lysozyme, polyglutamate, polylysine and combinations of all three were evaluated as compared to hyaluronic acid. A standard wound on the parietal peritoneum in mice was used and the evaluated agents were administered immediately postoperatively. The extent of peritoneal adhesions to the injured area was measured and expressed as a percentage of the wound length as evaluated after 7 days. Flow cytometry was performed to evaluate the effect on peritoneal macrophage survival and phagocytic function and the Pick test was used to determine peroxide production in order to estimate toxicity and potential impairment of macrophage function caused by the chemicals.Results. Significant differences were seen among the treatment groups (p<0.001). Both polyglutamate and lysozyme, and polyglutamate together with polylysine significantly decreased adhesion formation as compared to hyaluronic acid. The polylysine–polyglutamate combination was still visible macroscopically on the peritoneal surface after 1 week, though not after 1 month. The polyglutamate–lysozyme mixture was less effective than these individual components alone. The chemicals did not show any toxic effects or altered function in macrophage cell culture.Conclusions. Lysozyme, polyglutamate and, most effectively, a polyglutamate–polylysine combination significantly decreased experimental abdominal adhesion formation. A strong mechanical connection to the wound and prolonged attendance in the surface were noted. Peritoneal phagocyte function did not seem to be influenced by the chemicals.

Dermatan Sulfate Is Involved in the Tumorigenic Properties of Esophagus Squamous Cell Carcinoma

Extracellular matrix, either produced by cancer cells or by cancer-associated fibroblasts, influences angiogenesis, invasion, and metastasis. Chondroitin/dermatan sulfate (CS/DS) proteoglycans, which occur both in the matrix and at the cell surface, play important roles in these processes. The unique feature that distinguishes DS from CS is the presence of iduronic acid (IdoA) in DS. Here, we report that CS/DS is increased five-fold in human biopsies of esophagus squamous cell carcinoma (ESCC), an aggressive tumor with poor prognosis, as compared with normal tissue. The main IdoA-producing enzyme, DS epimerase 1 (DS-epi1), together with the 6-O- and 4-O-sulfotransferases, were highly upregulated in ESCC biopsies. Importantly, CS/DS structure in patient tumors was significantly altered compared with normal tissue, as determined by sensitive mass spectrometry. To further understand the roles of IdoA in tumor development, DS-epi1 expression, and consequently IdoA content, was downregulated in ESCC cells. IdoA-deficient cells exhibited decreased migration and invasion capabilities in vitro, which was associated with reduced cellular binding of hepatocyte growth factor, inhibition of pERK-1/2 signaling, and deregulated actin cytoskeleton dynamics and focal adhesion formation. Our findings show that IdoA in DS influences tumorigenesis by affecting cancer cell behavior. Therefore, downregulation of IdoA by DS-epi1 inhibitors may represent a new anticancer therapy.

TLR4 dependent heparan sulphate-induced pancreatic inflammatory response is IRF3-mediated

BackgroundDegraded extracellular matrix can stimulate the innate immune system via the Toll-Like Receptor-4 (TLR4). In the pancreas, syndecan-anchored heparan sulphate (HS) on the ductal epithelium can be cleaved off its protein cores by the proteases (trypsin and elastase) and potentially activate TLR4 signalling.MethodsTo investigate this signalling event, a low sulphated HS (500 μg/ml) was infused into the biliary-pancreatic duct of C57BL/6J wild-type mice. Phosphate buffered saline (PBS) and lipopolysaccharide (LPS) were used as negative and positive controls, respectively. Mice were sacrificed after 1, 3, 6, 9, and 48 hours and tissues were analysed for neutrophil and cytokine contents. In order to study the TLR4 signalling pathway of HS in the pancreas, genetically engineered mice lacking TLR4, Myeloid Differentiation primary response gene (88) (MyD88) or Interferon Regulatory Factor 3 (IRF3) were subjected to pancreatic infusion of HS.ResultsNeutrophil sequestration and corresponding myeloperoxidase (MPO) activity in the pancreas were increased 9 hours following HS challenge. In wild-type mice, the monocyte chemoattractant protein-1(MCP-1) increased at 3 hours after infusion, while RANTES increased after 9 hours.TLR4, MyD88, and IRF3 knockout mice showed an abrogated neutrophil recruitment and myeloperoxidase activity in the HS group, while the LPS response was only abolished in TLR4 and MyD88 knockouts.ConclusionsThe results of this study show that HS is capable of initiating a TLR4-dependent innate immune response in the pancreas which is distinctly different from that induced by LPS. This inflammatory response was mediated predominantly through IRF3- dependent pathway. Release of HS into the pancreatic duct may be one important mediator in the pancreatic ductal defence.

Novel treatment in peritoneal adhesion prevention: Protection by polypeptides

Objective. To evaluate a novel antiadhesive polypeptide complex containing a combination of poly-L-glutamate and poly-L-lysine in order to study its effectiveness and mechanisms in the prevention of postoperative abdominal adhesions in mice. Material and methods. The length of peritoneal adhesions was measured and expressed in percentage of the wound length in a standardized peritoneal injury model and evaluated 7 days and 4 weeks after adhesion induction. The test compound was administered intraperitoneally following surgery. Peritoneal swabs, including the wound area, were stained in order to determine the peritoneal location and clearance of the polypeptides. Electron microscopy was performed to analyze the wound surface and the ultra-structural changes of the phagocytes in cell culture. Moreover, flow cytometry was used to evaluate the effect on macrophage phagocytic function. Results. The poly-L-lysine and poly-L-glutamate combination significantly decreased peritoneal adhesions both at 7 days’ (p<0.001) and 4 weeks’ (p≤0.001) follow-up. From the first day, the compound was found in the wound, after which this was gradually rebuilt, and covered with mesothelial cells. The macrophages phagocytosed the test compound particles, resulting in significant cell growth, and large phagocytic vacuoles. Conclusions. The intraperitoneal administration of poly-L-lysine and poly-L-glutamate resulted in a significant decrease in experimental postoperative peritoneal adhesions.

Initiation of acute pancreatitis by heparan sulphate in the rat.

Objective. The initiating events in the onset of pancreatitis are poorly understood. Possible candidates may be endogenous ligands, acting on receptors within ductal, acinar or stellate cells, which have previously been shown to cause a systemic inflammatory response syndrome. The aim of this study was to investigate whether acute pancreatitis could be induced by heparan sulphate (HS)infused into the pancreatic ducts in the rat. Material and methods. Retrograde biliary-pancreatic infusion of heparan sulphate of different structures, taurodeoxycholate (TDC) or phosphate buffered saline (PBS) was performed. Local pancreatic inflammation was evaluated after 6 h by means of morphological evaluation, neutrophil and macrophage infiltration and levels of plasma amylase. Systemic inflammation was evaluated by measuring plasma IL-6, MCP-1 and CINC-1 concentrations. Results. Heparan sulphate induced a local inflammatory response visualized as a rapid infiltration of neutrophils and macrophages into the pancreas. Heparan sulphate induced inflammation and oedema without causing damage to acinar cells, as measured by morphological changes and plasma amylase concentrations. Furthermore, an increase in serum concentrations of CINC-1 and IL-6 was seen. The positive control (TDC) had increased levels of all variables analysed and the negative control (heparan sulphate administered intraperitoneally) was without effects. Conclusions. Our findings suggest a receptor-mediated innate immune response of the pancreatic cells induced by heparan sulphate. This finding may be helpful in elucidating some of the mechanisms involved during the initiation of pancreatitis, as well as in the search for a potential future therapeutic application.

Treatment with anti-factor VIIa in acute pancreatitis in rats : Blocking both coagulation and inflammation?

Objective. Acute pancreatitis starts as an autodigestive process restricted to the pancreas and progresses to a systemic inflammation via cytokine release into the blood stream. Several inhibitors of the coagulation cascade, including active-site-inactivated factor VIIa, have shown anti-inflammatory properties in other inflammatory models than acute pancreatitis. Free radical scavengers have proven useful in reducing the oxidative damage during hyperinflammatory conditions. The aim of this study was to investigate whether pretreatment with FVIIai would have any effect on the multiple organ dysfunction syndrome (MODS) in severe acute pancreatitis. Material and methods. Experimental acute pancreatitis was induced by intraductal infusion of taurodeoxycholate in the pancreatic duct. The animals were pretreated with N-acetyl-cysteine and active-site-inactivated factor VIIa. Neutrophil infiltration in the lungs, ileum and colon was quantified by myeloperoxidase activity. Inflammatory markers, IL-6 and MIP-2, were measured using ELISA. Results. Tissue infiltration of neutrophils in the lungs, ileum and colon significantly increased during acute pancreatitis as compared to sham operation. These levels were reduced by pretreatment with N-acetylcysteine and active-site-inactivated factor VIIa. Levels of interleukin-6 and macrophage inflammatory protein-2 increased significantly during acute pancreatitis. Pretreatment with NAC and FVIIai reduced these levels. Conclusions. Both N-acetylcysteine and active-site-inactivated factor VIIa showed powerful anti-inflammatory properties in experimental acute pancreatitis. As they exert their effects through different physiological mechanisms, they represent potential candidates for future multimodal treatment of acute pancreatitis.

Increasing anastomosis safety and preventing abdominal adhesion formation by the use of polypeptides in the rat

Background and aimsPostoperative adhesions can potentially be reduced using different anti-adhesive agents, though these drugs tend to compromise healing of an intestinal anastomosis. No method that significantly increases anastomosis safety is known at present. The aim of the study was to develop a concept of preventing postoperative adhesions using differently charged bioactive polypeptides, also considering healing and safety of an intestinal anastomosis.MethodsAn ileocolic anastomosis was performed under both “clean” and “septic” conditions in the rat. The treatment group received intraperitoneal poly-l-lysine and poly-l-glutamate, while controls received sodium chloride. Abdominal adhesions, anastomosis leakage and burst pressure were analysed after 1, 3, 5 and 7 days in the clean anastomosis model and after 7 days in the septic model.ResultsA significant decrease (p<0.01) in the amount of adhesions was seen in animals treated with polypeptides after 1, 3 and 5 days, while no difference was seen after 7 days. The anastomosis demonstrated a significantly higher burst pressure as evaluated at days 1 and 3 (p<0.05 and p<0.01, respectively) in the polypeptide-treated animals, while no difference was seen between the groups at day 5 or 7.ConclusionThe use of differently charged polypeptides administered intraperitoneally after surgery resulted in a significant decrease in the extent of postoperative adhesions. Furthermore, an increase in intestinal anastomosis safety, based on improved burst pressure during the first 3 days, i.e. the critical period during the healing process, was noted. No adverse effects were seen in surgery during septic conditions.

Differently charged polypeptides in the prevention of post-surgical peritoneal adhesions.

Objective. Peritoneal adhesions develop after almost all surgical interventions in the abdomen. We have developed an efficient treatment against post-surgical adhesions consisting of a combination of positively charged poly-L-lysine and negatively charged poly-L-glutamate. The aim of the present study was to further develop the concept of applying oppositely charged polypeptides in the prevention of adhesion formation, by evaluating different doses of the peptides, alterations in the way of administration, and also testing alternative components. Material and methods. Eighty-five NMRI mice were divided into six groups. A standardized peritoneal injury model was used. The groups received physiologic sodium chlorine, poly-L-lysine+poly-L-glutamate, low molecular weight poly-L-lysine+poly-L-glutamate, locally administered poly-L-lysine+poly-L-glutamate, in vitro mixed poly-L-lysine+poly-L-glutamate and poly-L-arginine+poly-L-glutamate, respectively. After 7 days, the extent of adhesion formation was determined during relaparotomy and was expressed as the mean percentage of the total wound length. Results. A significant decrease (p <0.001) in the peritoneal adhesion rate was detected in all groups, with the exception of the group administered poly-L-arginine. Among those animals that received poly-L-lysine and poly-L-glutamate, the low dose of poly-L-lysine administration resulted in the most pronounced anti-adhesive effect. Conclusions. The most effective polypeptide combination was poly-L-lysine and poly-L-glutamate, also showing effectiveness when used at low doses and by local application. The differences in adhesion prevention and the possible underlying mechanisms are discussed and the key role of poly-L-lysine is elucidated.