Therapeutic efficacy of continuous arterial infusion of an antibiotic and a protease inhibitor via the superior mesenteric artery for acute pancreatitis in an animal model

Matrix metalloproteinase-9 derived from polymorphonuclear neutrophils increases gut barrier dysfunction and bacterial translocation in rat severe acute pancreatitis

BACKGROUND

The role of polymorphonuclear neutrophil granulocytes (PMNs) and the PMN-derived protease, which is called matrix metalloproteinase-9 (MMP-9), for the gut barrier dysfunction in severe acute pancreatitis (SAP) has not yet been clarified. The aim of this study was to evaluate the effects of PMNs and MMP-9 on gut barrier dysfunction in rat SAP.

METHODS

SAP was induced by the injection of 5% sodium taurocholate, and anti-rat PMN serum or BB-94 were administered 48 h and 24 h, respectively, before the induction of acute pancreatitis. Twenty-four hours after the induction of acute pancreatitis, the gut barrier dysfunction and the incidence of bacterial translocation (BT) and PMN transmigration were investigated by bacterial, histologic, and biochemical (MPO) analysis. Inhibition of MMP-9 was achieved by depletion of PMNs or inhibition of MMP-activity by a broad-spectrum MMP inhibitor and confirmed by zymography. In addition, reactive oxygen species were evaluated by spin trap assay.

RESULTS

The mucosal injury and the infiltration of PMNs into the gut tissue of rats with SAP were significantly increased in comparison with rats treated with anti-rat PMN serum or BB-94. The levels of MMP-9 and reactive oxygen species in the gut of rats with SAP were significantly higher than those of the rats treated with anti-rat PMN serum or BB-94. Pretreatment with anti-rat PMN serum or BB-94 reduced the incidence of BT in SAP.

CONCLUSION

The incidence of BT in SAP was prevented by the depletion of PMNs or less pronounced by the injection of the MMP inhibitor BB-94. PMNs play an important pathophysiologic role in the occurrence of BT, and MMP-9 is involved in both BT and PMN transmigration in rat SAP.

Continuous regional arterial infusion therapy for acute necrotizing pancreatitis due to Mycoplasma pneumoniae infection in a child

A case of acute necrotizing pancreatitis due to Mycoplasma pneumoniae infection was treated in an 8-year-old girl. She experienced acute pancreatitis during treatment for M. pneumoniae. Contrast-enhanced computed tomographic scan revealed necrotizing pancreatitis. The computed tomographic severity index was 8 points (grade E). A protease inhibitor, ulinastatin, was provided via intravenous infusion but was ineffective. Continuous regional arterial infusion therapy was provided with gabexate mesilate (FOY-007, a protease inhibitor) and meropenem trihydrate, and the pancreatitis improved. This case suggests that infusion therapy is safe and useful in treating necrotizing pancreatitis in children.

Effects of nafamostat mesilate on the prevention of cerulein-induced acute pancreatitis

OBJECTIVES

Protease inhibitors showed protective effects on animal models of acute pancreatitis when administered before induction of pancreatitis, and results when administered after induction are uncertain. We assessed the effects of nafamostat mesilate in a mouse model of cerulein-induced pancreatitis comparing results of before and after induction.

METHODS

Cerulein was injected to mice intraperitoneally to induce pancreatitis, and they received intravenous nafamostat mesilate before and after induction. Serum concentrations of amylase and lipase, histological changes, and tissue expression of myeloperoxidase were measured. In addition, tissue activation of p38 mitogen-activated protein kinase (MAPK) and interleukin-6 was evaluated.

RESULTS

Development of pancreatitis was prevented by pretreatment with nafamostat mesilate. However, such effect was not shown when given after induction, although it partially suppressed myeloperoxidase expression and infiltration of inflammatory cells. Tissue expression of phospho-p38 MAPK was prominent in mice with pancreatitis and suppressed by pretreatment with nafamostat mesilate. Interleukin-6 expression was not influenced by either cerulein or nafamostat mesilate.

CONCLUSIONS

The development of pancreatitis was prevented by treating mice with nafamostat mesilate before induction, however, this finding was not observed if administered after injection of cerulein. Pretreatment with nafamostat mesilate suppressed activation of p38 MAPK.

Consensus of primary care in acute pancreatitis in Japan

The incidence of acute pancreatitis in Japan is increasing and ranges from 187 to 347 cases per million populations. Case fatality was 0.2% for mild to moderate, and 9.0% for severe acute pancreatitis in Japan in 2003. Experts in pancreatitis in Japan made this document focusing on the practical aspects in the early management of patients with acute pancreatitis. The correct diagnosis of acute pancreatitis and severity stratification should be made in all patients using the criteria for the diagnosis of acute pancreatitis and the multifactor scoring system proposed by the Research Committee of Intractable Diseases of the Pancreas as early as possible. All patients diagnosed with acute pancreatitis should be managed in the hospital. Monitoring of blood pressure, pulse and respiratory rate, body temperature, hourly urinary volume, and blood oxygen saturation level is essential in the management of such patients. Early vigorous intravenous hydration is of foremost importance to stabilize circulatory dynamics. Adequate pain relief with opiates is also important. In severe acute pancreatitis, prophylactic intravenous administration of antibiotics at an early stage is recommended. Administration of protease inhibitors should be initiated as soon as the diagnosis of acute pancreatitis is confirmed. A combination of enteral feeding with parenteral nutrition from early stage is recommended if there are no clear signs and symptoms of ileus and gastrointestinal bleeding. Patients with severe acute pancreatitis should be transferred to ICU as early as possible to perform special measures such as continuous regional arterial infusion of protease inhibitors and antibiotics, and continuous hemodiafiltration. The Japanese Government covers medical care expense for severe acute pancreatitis as one of the projects of Research on Measures for Intractable Diseases.

Selected biochemical parameters and ultrastructural picture of pancreas due to Ulinastatin treatment of experimental acute pancreatitis

Urinary trypsin inhibitor (UTI, Ulinastatin) is a protease inhibitor that has not been yet used in Europe in any experimental trial of severe acute pancreatitis. We have combined the experimental model of severe, hemorrhagic form of acute pancreatitis, and pharmacological treatment with a protease inhibitor. Male Wistar rats were divided into four experimental groups: healthy controls, operated, operated with experimentally induced acute pancreatitis, and animals with acute pancreatitis--treated with UTI preparations. Subjects in the last group were administered UTI intraperitoneally 1 h after pancreatitis induction in an average standard dose of 3000 units/animal. Additionally, four subgroups were created in this treated group, based on the UTI administration time--number of standard doses received: 2 h - 1 standard dose, 6 h - 5 standard doses, 12 h - 11 doses, 24 and 48 h - 15 doses. Statistically significant differences in the serum amylase and lipase activity between the UTI-treated and non-treated subjects were found. In the group of non-treated animals, there a profound destruction of cellular organelles was observed with a total degradation of nuceli, endoplasmatic reticulum and zymogen granules. However, in the UTI-treated subjects, pathological processes proceeded with the significantly slower pace and in much smaller quantities.

Rat experimental model of continuous regional arterial infusion of protease inhibitor and its effects on severe acute pancreatitis

OBJECTIVES

The rat experimental model of continuous regional arterial infusion of protease inhibitor (CRAI) on acute pancreatitis has yet to be established. Therefore, the aims of this study were (1) to establish the rat experimental model of CRAI and (2) to evaluate the effects of nafamostat on rat severe acute pancreatitis via different routes of administration.

METHODS

The rat internal jugular vein or the celiac artery was infused with nafamostat, and the concentration of nafamostat in the lung and pancreas was measured. After the induction of severe acute pancreatitis, rats received intravenous or regional intraarterial infusion of nafamostat and then concentrations of trypsinogen activated peptide (TAP) and serum interleukin (IL-6), and histologic sections of the pancreas were examined and the 96-hour survival rate was evaluated.

RESULTS

CRAI rats had higher concentrations of nafamostat in the pancreas than those infused intravenously. However, CRAI rats had lower concentrations of nafamostat in the lung that those infused intravenously. CRAI significantly reduced the levels of TAP and pancreatic necrosis. Moreover, the levels of serum IL-6 and the mortality rate were significantly reduced after CRAI compared with the intravenous infusion of nafamostat.

CONCLUSION

The effectiveness of the rat experimental model of CRAI on acute pancreatitis was clearly demonstrated. The concentration of nafamostat in the lung and pancreas and the effects of nafamostat differ according to the route of administration.

Efficacy of continuous regional arterial infusion of a protease inhibitor and antibiotic for severe acute pancreatitis in patients admitted to an intensive care unit

To investigate the efficacy of continuous regional arterial infusion (CRAI) of a protease inhibitor and antibiotic for severe acute pancreatitis (SAP) in patients admitted to an intensive care unit (ICU). A total of 51 patients with SAP requiring admission to an ICU were studied. The patients were divided into two groups: one received the protease inhibitor nafamostat mesylate and the antibiotic imipenem by continuous regional arterial infusion (CRAI group) and the other received protease inhibitors and antibiotics by intravenous infusion (non-CRAI group). To evaluate the therapeutic usefulness of CRAI of a protease inhibitor and antibiotic for SAP, the rate of surgery and the cumulative survival rate were compared between the non-CRAI group and the CRAI group. The rate of surgery was 32% in the non-CRAI group and 9% in the CRAI group (P = 0.08). Cumulative survival rates at 1, 6, and 12 months were 77.9%, 48.9%, and 48.9% in the non-CRAI group compared with 100.0%, 100.0%, and 87.1% in the CRAI group. Outcome was thus significantly better in the CRAI group than in the non-CRAI group (P = 0.002). CRAI of a protease inhibitor and antibiotic may decrease the need for surgical therapy and reduce mortality in patients with SAP.

Bacterial lipopolysaccharide decreases thrombomodulin expression in the sinusoidal endothelial cells of rats -- a possible mechanism of intrasinusoidal microthrombus formation and liver dysfunction

BACKGROUND/AIMS

To elucidate the mechanism of liver dysfunction occurring in patients with sepsis, we evaluated the effect of bacterial lipopolysaccharide (LPS) on the expression of thrombomodulin (TM) in rat sinusoidal endothelial cells (SECs) and the therapeutic efficacy of exogenous recombinant TM.

METHODS

We induced endotoxemia in rats by bolus intraperitoneal injection of LPS. TM antigen levels within tissues were assessed by immunohistochemistry. We measured TM in cultured SECs by enzyme immunoassay, functional analysis and real-time polymerase chain reaction (PCR).

RESULTS

TM antigen and activity levels were significantly decreased in SECs isolated from LPS-treated rats after 3 and 6 h treatment, and recovered after 12 h treatment, correlating with immunohistochemical observations. In contrast, TM messenger RNA was decreased after 6 and 12 h treatment, and slightly recovered after 24 h treatment. TM expression in cultured SECs isolated from normal rats was also reduced after treatment with LPS and tumor necrosis factor (TNF)-alpha in vitro. The increased levels of serum fibrin degradation products (FDP), fibrin deposition within liver sinusoids, injury of SECs and liver dysfunction induced by LPS in our rat model was improved by recombinant TM treatment.

CONCLUSIONS

Decreased TM expression in SECs of LPS-treated rats may result in intrasinusoidal microthrombus formation and subsequent liver dysfunction during sepsis.

The elongated PAP II/Reg III mRNA is upregulated in rat pancreas during acute experimental pancreatitis

INTRODUCTION

The pathogenesis and the mechanism of the development of severe acute pancreatitis are not clearly understood.

AIMS

We performed differential display analysis to find genes that show transcriptional changes in the pancreas during the development of severe acute pancreatitis in the rat.

METHODOLOGY

Twenty candidate pancreatitis-associated complementary DNA (cDNA) fragments were isolated. cDNA sequencing and subsequent database analysis revealed that one fragment (C18-2) among the 20 cDNA fragments showed no significant sequence similarity to previously reported genes, suggesting that it represented a novel gene. The rapid and high expression of C18-2 during the acute phase of pancreatitis suggested that the gene was involved in the development of acute pancreatitis. Therefore, we used rapid amplification of cDNA ends and identified the full-length cDNA.

RESULTS

Analysis of the open reading frame of the cDNA indicated that the deduced protein from the messenger RNA (mRNA) was a polypeptide of 174 amino acids, unexpectedly similar to that of a known gene, rat pancreatitis-associated protein II/regenerating gene III (PAP II/Reg III). However, the length of the identified mRNA (1,467 base pairs) was longer than that of rat PAP II mRNA (885 base pairs), because the elongated mRNA was generated through the different polyadenylation site in the same gene. The elongated mRNA after acute pancreatitis was strongly induced in the restricted early phase, in comparison with the original mRNA.

CONCLUSION

It is considered that the elongated mRNA affects the function of PAP II/Reg III protein because the elongated mRNA with long 3; untranslated regions is known to be involved in the translation efficiency. The identified mRNA may play an important role in the progression of pancreatitis.

Liver injury in acute pancreatitis and mitigation by continuous arterial infusion of an antibiotic via the superior mesenteric artery

Macrophage-derived inflammatory mediators, such as tumor necrosis factor-alpha (TNF-alpha), have been shown to play a central role in aggravation of acute pancreatitis (AP), but little is known about their roles in liver injury. We investigated the pathogenesis of the liver injury in AP and assessed the efficacy of arterial infusion of an antibiotic via the superior mesenteric artery (SMA). Infusion of saline (group A) or imipenem (group B) was started 6 hours after induction of AP in dogs by intraductal administration of autologous gallbladder bile. The survival rate in group B was significantly improved compared with group A. Serum alanine aminotransferase levels in peripheral blood and endotoxin levels in portal vein blood were both significantly higher at 18 hours in group A than in group B. When hepatocytes and Kupffer cells were isolated at 18 hours and cultured for 24 hours thereafter, there was significant exacerbation of the hepatocyte injury and significantly greater production of TNF-alpha in the coculture of hepatocytes and Kupffer cells in group A, indicating that the Kupffer cells had been activated. By contrast, both of these manifestations were significantly mitigated in group B. These findings suggest that TNF-alpha secreted by endotoxin-activated Kupffer cells contributes to liver injury in AP, and that SMA infusion of an antibiotic mitigates the liver injury by controlling endotoxin translocation.