Pathophysiology of alcohol-induced pancreatitis

Pain Intensity, Pain-Related Anxiety, and Hazardous Drinking Among Individuals With PTSD

OBJECTIVE

Evidence suggests that pain intensity may be indirectly linked to hazardous drinking and PTSD symptom severity via pain-related anxiety. The goal of this analysis was to test the hypotheses in a population with PTSD symptoms that pain intensity would be positively and indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via pain-related anxiety.

METHODS

Heavy drinkers with probable PTSD were recruited via Qualtrics panels (N = 371, 53% Female, Mage = 39.68, SD = 10.86). Linear regression and conditional process models were conducted to examine indirect associations between pain intensity and primary outcomes via pain-related anxiety.

RESULTS

Pain intensity was found to be indirectly associated with hazardous drinking, alcohol dependence, alcohol-related problems, and PTSD symptom severity via greater pain-related anxiety.

CONCLUSION

These initial findings suggest that pain-related anxiety may play an important role in relations between the experience of pain and hazardous patterns of alcohol consumption among individuals with probable PTSD. Future research is needed to determine the temporal nature of these associations and to examine the potential utility of treatments that address pain-related anxiety in the context of comorbid pain, PTSD, and hazardous drinking.

Alcohol use severity in relation to pain severity and interference among latinx adults with current pain who smoke cigarettes

Limited research has focused expressly on dual tobacco-alcohol use among the Latinx population. Latinx individuals who smoke represent a tobacco health disparities group and evince elevated rates of pain problems and symptoms. Prior research has consistently linked pain problems and severity to smoking and alcohol prevalence, maintenance, and behavior. Accordingly, the current study sought to build from the limited work that exists among Latinx persons who smoke and evaluate the role of alcohol use severity in terms of pain severity and interference. The current sample consisted of 228 adult Latinx daily cigarette smokers (Mage = 34.95 years; SD = 8.58; 39.0% female) who endorsed current pain. Results indicated that elevated alcohol use problems were associated with greater levels of pain severity (R2 = 0.06) and interference (R2 = 0.06). The present findings suggest that there may be utility in clinical screening for alcohol use problems among Latinx persons who smoke to offset pain problems among this high-risk group.

Challenges in Diagnosing Sudden Death Caused by Acute Hemorrhagic Pancreatitis: An Autopsy-Based Case Report

Forensic pathologists frequently encounter cases of sudden natural death. Most sudden natural deaths are attributed to cardiac causes. Acute pancreatitis, especially hemorrhagic pancreatitis, is an infrequent yet critical contributor to sudden death. The role of a forensic pathologist is imperative in such cases to find out the cause of the sudden death and to either confirm or refute any allegations. In this context, we describe a case of a 34-year-old male who experienced sudden death due to acute hemorrhagic pancreatitis, highlighting the need for a detailed autopsy, pathophysiological insights, and diagnostic challenges.

Cognitive-Affective Transdiagnostic Factors Associated With Vulnerability to Alcohol and Prescription Opioid Use in the Context of Pain

The use of alcohol and prescription opioids is common among people in pain and poses significant public health burdens. This review identifies factors associated with motivation to use alcohol and prescription opioids in the context of pain. Pain-relevant, cognitive-affective, transdiagnostic vulnerability factors-expectancies/motives, pain catastrophizing, pain-related anxiety, distress intolerance, anxiety sensitivity, and perceived interrelations-were selected from theoretical conceptualizations of pain and substance use. Searches conducted in PubMed, PsycINFO, and Embase returned 25 studies that examined associations between identified variables of interest and the use of alcohol and prescription opioids in the context of pain. Consistent with a larger literature on pain and substance use, the studies included in this review demonstrated that people with chronic pain are motivated to use alcohol and opioids in response to negative affect and hold expectancies/motives for coping with pain. Vulnerabilities that engender difficulty managing aversive internal states (distress intolerance and anxiety sensitivity) and maladaptive responses to pain (pain-related anxiety and pain catastrophizing) also were implicated in motivation for alcohol and opioid use. Although one study found that pain-related anxiety was associated with co-use of alcohol and opioids, no studies examined simultaneous use. Future research directions that can explicate causal associations, identify patterns of alcohol and opioid co-use, clarify the role of pain in cessation processes, and inform treatment development are discussed.

A measure of expectancies for alcohol analgesia: Preliminary factor analysis, reliability, and validity

Rates of alcohol consumption are substantially higher among persons with pain, and recent research has focused on elucidating bidirectional pain-alcohol effects. Expectancies for alcohol analgesia could influence the degree to which alcohol confers acute pain-relieving effects, and may amplify the propensity to respond to pain with drinking behavior. However, no validated measures of expectancies for alcohol analgesia are available. Therefore, we developed a five-item measure of Expectancies for Alcohol Analgesia (EAA), which assesses the perceived likelihood that alcohol will reduce pain. The goal of this project was to examine psychometric properties of the EAA among a sample of 273 current alcohol users with chronic pain (M_age = 32.9; 34% female) who completed an online survey of pain and substance use. Confirmatory factor analysis (CFA) results indicated that the hypothesized single-factor structure of the EAA provided good model fit (Bollen-Stine bootstrap p = .13). The EAA also showed excellent internal consistency (α = 0.97), and scores were positively associated with quantity/frequency of alcohol use, alcohol outcome expectancies, coping-related drinking motives, and pain severity (ps < 0.01). These findings provide initial support regarding the single-factor structure, reliability, and validity of the EAA. Examination of predictive utility and further validation are important next steps.

Pathophysiological Events Associated With Pancreatitis in Response to Tobacco: An In Vitro Comparative Study With Ethanol in Primary Acinar Cell Culture

OBJECTIVES

The aim of this study was to comparatively analyze the effects of different concentrations of cigarette smoke condensate (CSC, a standardized tobacco extract) and ethanol on intracellular enzyme activation, cell necrosis, alteration of cytosolic calcium concentration ([Ca]c), and amylase secretion in pancreatic acinar cells.

METHODS

The effects of CSC (1 μg/mL to 0.4 mg/mL) and ethanol (10-100 mM) on intracellular enzyme activity, cell necrosis, and [Ca]c were measured by fluorescence assays in isolated pancreatic acinar cells. Amylase secretion was evaluated by spectrophotometry. Supramaximal concentrations of cholecystokinin (10-100 nM) were used as positive control.

RESULTS

Neither CSC nor ethanol induced trypsin or elastase activation. Both CSC (0.1-0.4 mg/mL) and ethanol (10-75 mM) significantly increased [Ca]c. Amylase secretion was increased only in CSC-treated cells (0.3 and 0.4 mg/mL). After 60 minutes, CSC (0.3 and 0.4 mg/mL) significantly increased acinar cell necrosis at a similar percentage to that induced by cholecystokinin. Ethanol did not induce any significant cell necrosis.

CONCLUSIONS

Cigarette smoke condensate induces acinar cell injury and increases [Ca]c and amylase secretion, independently of intracellular enzyme activation, suggesting that tobacco could induce several main early events of pancreatitis in pancreatic acinar cells. However, ethanol only induces increases [Ca]c, having no effect on cell injury, amylase secretion, or intracellular enzyme activation.

Substance-related disorders: A review of prevalence and correlates among patients with chronic pain

Over the past few decades, research has revealed high rates of substance-related disorders among patients with chronic pain. In addition to their potentially deleterious health consequences, substance-related disorders have consistently been associated with negative pain-related outcomes among patients with chronic pain. The goal of this narrative review was to provide an overview of studies that have examined the prevalence and correlates of substance-related disorders among patients with chronic pain. A particular focus was placed on opioids, sedatives/hypnotics, cannabis, tobacco, and alcohol given that these substances have received the bulk of research attention among patients with pain. Research conducted to date suggests that a host of biological and psychological factors are likely to contribute to the elevated rates of substance-related disorders among patients with chronic pain. In this review, in addition to reviewing the prevalence and correlates of substance-related disorders among patients with pain, we briefly discussed the changes that were recently made from the DSM-4 to the DSM-5 in the diagnostic criteria for substance-related disorders, and the implications of these changes for the assessment of patients with chronic pain. We also provided a brief overview of instruments that can be used for the assessment of these disorders in clinical and research settings.

Sudden Death Due to Acute Pancreatitis

Acute pancreatitis can present as sudden, expected death and, therefore, fall under the jurisdiction of the medical examiner/coroner (ME/C). Although its etiologies are varied, alcohol abuse, trauma, and drugs are important to consider in the forensic setting. It is therefore important for the forensic pathologist to have an understanding of these and other etiologies, to have a functional knowledge of the pancreatic anatomy and physiology, and to be able to diagnose acute pancreatitis and distinguish it from postmortem artifact. This review will highlight the forensic aspects of acute pancreatitis, with particular focus on acute hemorrhagic pancreatitis. This will include an overview of the developmental anatomy and normal physiology of the pancreas, the various causes of pancreatitis that may result in deaths coming to the attention of the ME/C, the underlying pathophysiology of the disease, the postmortem diagnosis of acute pancreatitis, and ancillary studies that support the diagnosis. Acad Forensic Pathol. 2018 8(2): 239-255.

Hsp90 regulation affects the treatment of glucocorticoid for pancreatitis-induced lung injury

Glucocorticoids are commonly used for the treatment of pancreatitis and complicated acute lung injury and help to reduce the mortality rates of both. The effect of gene variants in heat shock protein 90 (Hsp90), a key chaperone molecule of the glucocorticoid receptor (GR), on the therapeutic effect of glucocorticoids is unclear. Our study aims to investigate the different susceptibility to glucocorticoid treatment in BALB/c and C57BL/6 mice carrying different Hsp90 genotypes in an animal model of pancreatitis-induced lung injury. Compared with BALB/c mice, C57BL/6 mice have lower mortality rates, decreased water content in their lungs, and a lower level of IL-1 beta in an animal model of acute pancreatitis. C57BL/6 mice show a greater therapeutic effect and increased GR binding activities with glucocorticoid responsive element compared to BALB/c mice after a 0.4 mg/kg dexamethasone (DEX) treatment. Treatment with a higher dose of DEX (4 mg/kg) significantly reduced mortality rates and increased GR-GRE binding activity in both strains of mice, and there was no significant difference between the two strains. DEX did not exert a protective role after geldanamycin, a specific inhibitor of Hsp90, was administered in both strains of mice. Our study revealed that Hsp90 gene variants are responsible for the greater therapeutic effect of DEX in C57BL/6 mice compared to BALB/c mice, which implies that combining DEX treatment with Hsp90 regulation would promote the efficiency of DEX and would be an effective way to alleviate the side effects of hormone therapy.

Alcohol Consumption and Cigarette Smoking are Important Modifiers of the Association Between Acute Pancreatitis and the PRSS1-PRSS2 Locus in Men

OBJECTIVES

The present study was designed to investigate whether the susceptibility to acute pancreatitis (AP) attributable to polymorphism rs10273639 at the PRSS1-PRSS2 locus is dependent on alcohol consumption and cigarette smoking.

METHODS

A total of 603 unrelated Russian individuals including 304 patients with physician-diagnosed AP and 299 sex- and age-matched healthy controls have been recruited for the study. A polymorphism rs10273639 (-408C>T) of PRSS1-PRSS2 was genotyped by TaqMan-based assay.

RESULTS

A variant allele -408T (P = 0.003) and genotypes -408CT plus TT (P = 0.002) were associated with decreased AP risk only in men. The odds ratios for AP in the CC homozygotes versus the variant genotypes were 1.95 [95% confidence interval (CI), 0.65-5.85; P = 0.23], 1.72 (95% CI, 0.93-3.20; P = 0.08), and 2.37 (95% CI, 1.09-5.13; P = 0.03) for men who consumed up to 28, 29 to 59, and more than 60 alcohol drinks a week, respectively. Cigarette smokers with the -408CC genotype had an increased risk of AP (odds ratio, 2.07; 95% CI, 1.25-3.42; P = 0.004), whereas nonsmoker carriers did not have a disease risk (odds ratio, 1.48; 95% CI, 0.58-3.82; P = 0.42).

CONCLUSIONS

We confirmed a robust association of polymorphism rs10273639 at PRSS1-PRSS2 with AP in the Russian population. The present study is the first to show that relationship between the locus and disease is significantly modified by alcohol consumption and cigarette smoking.

Effect of oral administration of AZD8309, a CXCR2 antagonist, on the severity of experimental pancreatitis

INTRODUCTION

Acute pancreatitis is a common gastrointestinal disorder burdened with a high mortality. Two pathophysiological events during experimental pancreatitis are thought to determine the clinical course: premature digestive protease activation and tissue infiltration by inflammatory cells. We have investigated the effect of AZD8309, a potent and orally bioavailable antagonist of the chemokine receptor CXCR2, which has been proposed to regulate the transmigration of neutrophils.

METHODS

Male C57BL6 mice (25-30 g) received gavage feeding of AZD8309 (50 mg/kg/BW) or mannitol (controls) twice daily starting 3 h prior to pancreatitis induction. Mild pancreatitis was induced by i.p. caerulein administration (50 μg/kg BW), severe pancreatitis by intraductal taurocholate (2%). Pancreas, lung, and serum was harvested up to 48 h after pancreatitis induction and used for histopathology, amylase, lipase, cathepsin B, trypsin, and elastase activity measurements, myeloperoxidase (MPO) content and cytokine concentrations.

RESULTS

Oral administration of AZD8309 significantly reduced MPO in the pancreas and lungs (8 h & 24 h) and reduced intrapancreatic trypsin and elastase activity (8 h) in caerulein-pancreatitis. In taurocholate-pancreatitis AZD8309 reduced cathepsin B activity and MPO. Serum cytokine levels were reduced by AZD8309 as well as histopathological damage.

CONCLUSION

The CXCR2 antagonist AZD8309 reduced the transmigration of neutrophils as well as intrapancreatic protease activation in experimental pancreatitis. This effect was sufficient to reduce the overall severity of the disease. CXCR2 may therefore be a viable therapeutic target and AZD8309 a suitable agent for the treatment of acute pancreatitis.

Pancreatitis: A Forensic Perspective

Among the numerous etiologies of acute and chronic pancreatitis, several underlying causes (e.g., chronic alcohol abuse, trauma, medical therapy) may result in a death that is reportable to the medical examiner/coroner. As such, forensic pathologists are likely to encounter pancreatitis at autopsy and therefore must be familiar with its etiologies, mechanisms of death, autopsy findings, and medicolegal investigation. This review will focus on the aspects of pancreatitis that may be useful to forensic pathologists in their daily practice. This includes determining if acute or chronic pancreatitis caused or contributed to death as well as determining the etiologically specific proximate cause of death. Current theories of how these various processes result in inflammation of the pancreas are reviewed.

Interrelations between pain and alcohol: An integrative review

Pain and alcohol use are both highly prevalent in the general population, and pain-alcohol interrelations are of increasing empirical interest. Previous research has identified associations between pain and alcohol dependence, and the current review provides novel contributions to this emerging domain by incorporating studies that have tested relations between pain and low-to-moderate alcohol consumption, and by identifying potential psychosocial mechanisms of action. Specifically, we sought to integrate evidence of pain-alcohol relations derived from two directions of empirical inquiry (i.e., effects of alcohol on pain and effects of pain on alcohol use) across psychological, social, and biological literatures. We observed converging evidence that associations between alcohol consumption and pain may be curvilinear in nature. Whereas moderate alcohol use was observed to be associated with positive pain-related outcomes (e.g., greater quality of life), excessive drinking and alcohol use disorder appear to be associated with deleterious pain-related outcomes (e.g., greater pain severity). We also observed evidence that alcohol administration confers acute pain-inhibitory effects, and that situational pain may motivate alcohol consumption (e.g., drinking for pain-coping). Future research can inform theoretical and clinical applications through examination of temporal relations between pain and alcohol consumption, tests of hypothesized mechanisms, and the development of novel interventions.

Fatty acid ethyl ester synthase inhibition ameliorates ethanol-induced Ca2+-dependent mitochondrial dysfunction and acute pancreatitis

OBJECTIVE

Non-oxidative metabolism of ethanol (NOME) produces fatty acid ethyl esters (FAEEs) via carboxylester lipase (CEL) and other enzyme action implicated in mitochondrial injury and acute pancreatitis (AP). This study investigated the relative importance of oxidative and non-oxidative pathways in mitochondrial dysfunction, pancreatic damage and development of alcoholic AP, and whether deleterious effects of NOME are preventable.

DESIGN

Intracellular calcium ([Ca(2+)](C)), NAD(P)H, mitochondrial membrane potential and activation of apoptotic and necrotic cell death pathways were examined in isolated pancreatic acinar cells in response to ethanol and/or palmitoleic acid (POA) in the presence or absence of 4-methylpyrazole (4-MP) to inhibit oxidative metabolism. A novel in vivo model of alcoholic AP induced by intraperitoneal administration of ethanol and POA was developed to assess the effects of manipulating alcohol metabolism.

RESULTS

Inhibition of OME with 4-MP converted predominantly transient [Ca(2+)](C) rises induced by low ethanol/POA combination to sustained elevations, with concurrent mitochondrial depolarisation, fall of NAD(P)H and cellular necrosis in vitro. All effects were prevented by 3-benzyl-6-chloro-2-pyrone (3-BCP), a CEL inhibitor. 3-BCP also significantly inhibited rises of pancreatic FAEE in vivo and ameliorated acute pancreatic damage and inflammation induced by administration of ethanol and POA to mice.

CONCLUSIONS

A combination of low ethanol and fatty acid that did not exert deleterious effects per se became toxic when oxidative metabolism was inhibited. The in vitro and in vivo damage was markedly inhibited by blockade of CEL, indicating the potential for development of specific therapy for treatment of alcoholic AP via inhibition of FAEE generation.

Rutin rich Emblica officinalis Geart. fruit extract ameliorates inflammation in the pancreas of rats subjected to alcohol and cerulein administration

BACKGROUND

The modulating effect of methanolic extract of Emblica officinalis (MEEO) on ethanol (EtOH)- and cerulein (Cer)-induced pancreatitis in rats was investigated in this study.

METHODS

Male albino Wistar rats were divided into four groups. Group 1 and 2 rats served as control and fed normal diet. Group 3 and 4 rats were fed isocalorically adjusted diet containing EtOH (36% of total calories) for 5 weeks and also subjected to intraperitoneal injection of Cer 20 µg/kg b.wt. thrice weekly for the last 3 weeks of the experimental period. In addition, group 2 and 4 rats received 200 mg/kg b.wt. of MEEO from 15th day till the experimental period. Serum levels of lipase (L), amylase (A), cytokines IL-1β, IL-18, caspase-1 and oxidative stress index (OSI) were determined. Levels of fecal trypsin, total collagen, caspase-1, myeloperoxidase (MPO), antioxidants and mRNA expression of caspase-1, IL-1β and IL-18 were determined in the pancreas.

RESULTS

HPLC analysis showed the presence of rutin in MEEO. We observed a significant elevation in serum L/A ratio, IL-1β, IL-18, caspase-1, OSI, collagen, MPO activity and the mRNA expression of IL-1β, IL-18 and caspase-1 and significant reduction in fecal trypsin and antioxidant status in EtOH- and Cer-administered rats. The inflammatory markers were found to be reduced and the antioxidant status of pancreas was maintained in MEEO-coadministered rats.

CONCLUSIONS

The rutin rich nature of E. officinalis can be claimed for its anti-inflammatory and pancreato protective effects.

Animal models for investigating chronic pancreatitis

Chronic pancreatitis is defined as a continuous or recurrent inflammatory disease of the pancreas characterized by progressive and irreversible morphological changes. It typically causes pain and permanent impairment of pancreatic function. In chronic pancreatitis areas of focal necrosis are followed by perilobular and intralobular fibrosis of the parenchyma, by stone formation in the pancreatic duct, calcifications in the parenchyma as well as the formation of pseudocysts. Late in the course of the disease a progressive loss of endocrine and exocrine function occurs. Despite advances in understanding the pathogenesis no causal treatment for chronic pancreatitis is presently available. Thus, there is a need for well characterized animal models for further investigations that allow translation to the human situation. This review summarizes existing experimental models and distinguishes them according to the type of pathological stimulus used for induction of pancreatitis. There is a special focus on pancreatic duct ligation, repetitive overstimulation with caerulein and chronic alcohol feeding. Secondly, attention is drawn to genetic models that have recently been generated and which mimic features of chronic pancreatitis in man. Each technique will be supplemented with data on the pathophysiological background of the model and their limitations will be discussed.

Summary of integrative medicine for severe acute pancreatitis: 26-year clinical experiences and a report of 1 561 cases

OBJECTIVE

To investigate the changing trends of clinical management for severe acute pancreatitis (SAP) with integrative medicine.

METHODS

Clinical data of 1 561 patients with SAP from 1980 to 2005 was retrospectively analyzed. The mortality and morbidity of complications were compared.

RESULTS

Of the 1 561 patients, 400 patients accepted surgical operation, while the rest were treated conservatively with integrative medicine. There was a change toward conservative management together with Chinese purgative herbal medication use after 1990 (22.4% from 1980-1990 compared with 45.5% from 1991-1993) because of high postoperative mortality. From 1994-2005, the treatment integrating Western medicine with Chinese herbal medications came to be preferred over the classic Western operation-based method. This change was associated with decreased morbidity (35.4% in 1980-1990 compared with 24.7% in 1991-1993 and 11.0% in 1994-2005, P<0.05) and lower mortality (40.52% of 1980-1990 compared with 17.17% of 1991-1993 and <10.25% of 1994-2005, P<0.05).

CONCLUSION

The combination of conservative management with Chinese herbal medicines is preferable to classic Western medicine treatment to reduce morbidity and mortality of SAP, while surgery becomes a supplemental option.

The relation between different dimensions of alcohol consumption and burden of disease: an overview

AIMS

As part of a larger study to estimate the global burden of disease and injury attributable to alcohol: to evaluate the evidence for a causal impact of average volume of alcohol consumption and pattern of drinking on diseases and injuries; to quantify relationships identified as causal based on published meta-analyses; to separate the impact on mortality versus morbidity where possible; and to assess the impact of the quality of alcohol on burden of disease.

METHODS

Systematic literature reviews were used to identify alcohol-related diseases, birth complications and injuries using standard epidemiological criteria to determine causality. The extent of the risk relations was taken from meta-analyses.

RESULTS

Evidence of a causal impact of average volume of alcohol consumption was found for the following major diseases: tuberculosis, mouth, nasopharynx, other pharynx and oropharynx cancer, oesophageal cancer, colon and rectum cancer, liver cancer, female breast cancer, diabetes mellitus, alcohol use disorders, unipolar depressive disorders, epilepsy, hypertensive heart disease, ischaemic heart disease (IHD), ischaemic and haemorrhagic stroke, conduction disorders and other dysrhythmias, lower respiratory infections (pneumonia), cirrhosis of the liver, preterm birth complications and fetal alcohol syndrome. Dose-response relationships could be quantified for all disease categories except for depressive disorders, with the relative risk increasing with increased level of alcohol consumption for most diseases. Both average volume and drinking pattern were linked causally to IHD, fetal alcohol syndrome and unintentional and intentional injuries. For IHD, ischaemic stroke and diabetes mellitus beneficial effects were observed for patterns of light to moderate drinking without heavy drinking occasions (as defined by 60+ g pure alcohol per day). For several disease and injury categories, the effects were stronger on mortality compared to morbidity. There was insufficient evidence to establish whether quality of alcohol had a major impact on disease burden.

CONCLUSIONS

Overall, these findings indicate that alcohol impacts many disease outcomes causally, both chronic and acute, and injuries. In addition, a pattern of heavy episodic drinking increases risk for some disease and all injury outcomes. Future studies need to address a number of methodological issues, especially the differential role of average volume versus drinking pattern, in order to obtain more accurate risk estimates and to understand more clearly the nature of alcohol-disease relationships.

Impaired autolysosome formation correlates with Lamp-2 depletion: role of apoptosis, autophagy, and necrosis in pancreatitis

BACKGROUND & AIMS

Acute pancreatitis constitutes a life-threatening condition in which pancreatic acinar cells undergo massive cell death. We investigated the incidence of apoptosis, autophagy, and necrosis affecting acinar cells in the early onset of acute pancreatitis induced by chronic alcohol feeding and acute endotoxemia.

METHODS

Rats were fed either an ethanol-containing or a control diet over 14 weeks and killed 3 or 24 hours after a single lipopolysaccharide injection. Apoptosis, necrosis, and autophagy of pancreatic acinar cells were assessed by histology, electron microscopy, immunofluorescence, and biochemical methods.

RESULTS

The combination of alcohol exposure and endotoxemia resulted in the depletion of several lysosomal proteins including lysosomal-associated membrane protein-2 (Lamp-2), a protein that is required for the proper fusion of autophagosomes with lysosomes. Accordingly, Lamp-2 depletion correlated with the accumulation of autophagosomes and a relative paucity of autolysosomes, reduced adenosine-5'-triphosphate levels, and a switch from apoptotic to necrotic cell death. This switch to necrosis was accompanied by reduced caspase activation and the nuclear release of the proinflammatory factor high mobility group box 1. Importantly, human patients with alcoholic pancreatitis also exhibited local Lamp-2 depletion, which points to a crucial role for Lamp-2 and autophagy in pancreatic acinar cell death.

CONCLUSIONS

Our data suggest that acinar cell vacuolization in pancreatitis is mediated by an endotoxemia-induced inhibition of the late stage of autophagy. The combination of alcohol and endotoxemia attenuated apoptosis response yet enhanced acinar cell necrosis. The depletion of lysosomal proteins plays a critical role in the early onset of acute pancreatitis.

Chronic pancreatitis: report from a multicenter Italian survey (PanCroInfAISP) on 893 patients

BACKGROUND

No data on chronic pancreatitis in Italy are available yet.

AIM

To evaluate demographic, clinical, diagnostic and therapeutic aspects in patients suffering from chronic pancreatitis.

PATIENTS AND METHODS

Eligible patients were prospectively enrolled from 2000 to 2005. Information concerning demographic data, lifestyle risk factors, family and clinical history, associated factors (alcohol, autoimmunity, cystic dystrophy of the duodenal wall, obstruction, genetic mutations) concomitant diseases, diagnostic findings, and pharmacological, endoscopic and surgical therapy were gathered.

RESULTS

893 patients (74% males, mean age 53.7+/-15.2 years) were evaluated. 519/859 patients (60%) were drinkers and 555/840 (66%) were smokers. A strong positive correlation between drinking and cigarette consumption (R=0.53; p<0.0001) was found. Heavy alcohol consumption (>80g of alcohol/day for more than 5 years) was considered the most important risk factor in 300 patients (34%), obstruction in 238 (27%), alcohol and obstruction in 82 (9%), autoimmunity in 34 (4%), cystic dystrophy of the duodenal wall/groove pancreatitis in 55 (6%), gene mutations in 36 (4%), and none (idiopathic) in 148 (17%). Bile stones were diagnosed in 287 patients (33%) and cholecystectomy was performed in 329 patients (38%). Pancreatic calcifications were diagnosed in 547/879 patients (62%). Pancreatic surgery was performed in 273 patients (31%). Endoscopic sphincterotomy was performed in 371 patients (42%). Exocrine and endocrine insufficiency were found, respectively, in 373/834 (45%) and 275/885 patients (31%).

CONCLUSIONS

An unexpected low frequency of alcohol abuse and new emerging associated risk factors for chronic pancreatitis were observed in Italy.

The calcium binding protein S100A9 is essential for pancreatic leukocyte infiltration and induces disruption of cell-cell contacts

Leukocyte infiltration is an early and critical event in the development of acute pancreatitis. However, the mechanism of leukocyte transmigration into the pancreas and the function of leukocytes in initiating acute pancreatitis are still poorly understood. Here, we studied the role of S100A9 (MRP14), a calcium binding protein specifically released by polymorph nuclear leukocytes (PMN), in the course of acute experimental pancreatitis. Acute pancreatitis was induced by repeated supramaximal caerulein injections in S100A9 deficient or S100A9 wild-type mice. We then determined S100A9 expression, trypsinogen activation peptide (TAP) levels, serum amylase and lipase activities, and tissue myeloperoxidase (MPO) activity. Cell-cell contact dissociation was analyzed in vitro with biovolume measurements of isolated acini after incubation with purified S100A8/A9 heterodimers, and in vivo as measurement of Evans Blue extravasation after intravenous application of S100A8/A9. Pancreatitis induced increased levels of S100A9 in the pancreas. However, infiltration of leukocytes and MPO activity in the lungs and pancreas during acute pancreatitis was decreased in S100A9-deficient mice and associated with significantly lower serum amylase and lipase activities as well as reduced intrapancreatic TAP-levels. Incubation of isolated pancreatic acini with purified S100A8/A9-heterodimers resulted in a rapid dissociation of acinar cell-cell contacts which was highly calcium-dependent. Consistent with these findings, in vivo application of S100A8/A9 in mice was in itself sufficient to induce pancreatic cell-cell contract dissociation as indicated by Evans Blue extravasation. These data show that the degree of intrapancreatic trypsinogen activation is influenced by the extent of leukocyte infiltration into the pancreas which, in turn, depends on the presence of S100A9 that is secreted from PMN. S100A9 directly affects leukocyte tissue invasion and mediates cell contact dissociation via its calcium binding properties.

Sphincter of Oddi function in the Australian brush-tailed possum is inhibited by intragastric ethanol

The role of sphincter of Oddi (SO) function in alcoholic acute pancreatitis (AP) is unclear. We aimed to compare the effect of i.v. and intragastric (IG) ethanol on SO function (i.e. trans-sphincteric flow; TSF) and investigate possible neural mechanisms. The involvement of gastric mucosal damage was also investigated by pretreatment with pantoprazole. In anaesthetized Australian possums, blood pressure (BP), TSF and blood ethanol concentrations were measured after i.v. or IG ethanol. Possums were subjected to acute vagotomy, atropine, L-nitro arginine methyl ester (L-NAME) or pantoprazole pretreatment prior to IG ethanol. BP was not significantly altered by ethanol. Ethanol decreased TSF in a dose and route-dependent manner. The lowest dose of IG ethanol reduced TSF but this response was not duplicated by i.v. ethanol producing the same blood ethanol concentrations. Acute vagotomy, atropine or L-NAME pretreatment blocked the ethanol-induced decrease in TSF and simultaneously suppressed the blood ethanol concentration. Pantoprazole pretreatment reduced the TSF response and blood ethanol concentrations implicating mechanisms induced by gastric mucosal damage. We conclude that ethanol (and/or its metabolites) reduces TSF via humoral and neural mechanisms involving vagal pathways, muscarinic receptors and nitric oxide. Reduced TSF could contribute to the onset of AP.

Genetic background of pancreatitis

Trypsin activity is properly suppressed by pancreatic secretory trypsin inhibitor (PSTI), which is also known as serine protease inhibitor Kazal type 1 (SPINK1), thereby preventing damage to pancreatic acinar cells as a first line of defence. However, if trypsin activation exceeds the capacity of PSTI/SPINK1, a subsequent cascade of events leads to the activation of various proteases that damage cells. Five mutations (R122H, N29I, A16V, D22G and K23R) in cationic trypsinogen and two mutations (N34S and M1T) in the PSTI/SPINK1 gene have been found to correlate significantly with the onset of pancreatitis. From analyses of hereditary pancreatitis and the phenotype of PSTI/SPINK1 (Spink3) knockout mice, we showed that the imbalance of trypsin activation and its inhibition by PSTI/SPINK1 would lead to the development of pancreatitis.

Acute pancreatitis: animal models and recent advances in basic research

Acute pancreatitis (AP) is characterized by edema, acinar cell necrosis, hemorrhage, and severe inflammation of the pancreas. Patients with AP present with elevated blood and urine levels of pancreatic digestive enzymes, such as amylase and lipase. Severe AP may lead to systemic inflammatory response syndrome and multiorgan dysfunction syndrome, which account for the high mortality rate of AP. Although most (>80%) cases of AP are associated with gallstones and alcoholism, some are idiopathic. Although the pathogenesis of AP has not yet been elucidated, a common feature is the premature activation of trypsinogen within pancreatic tissues, which triggers autodigestion of the gland. Recent advances in basic research suggest that etiologic factors including cyclooxygenase-2, substance P, and angiotensin II may have novel roles in this disease. Basic research data obtained thus far have been based on animal models of AP ranging from mild edematous pancreatitis to severe necrotizing pancreatitis. In view of this, an adequate selection of experimental animal models is of paramount importance. Notwithstanding these animal models, it should be emphasized that none of these models mimic the clinical situation where varying degrees of severity usually occur. In this review, commonly used animal models of AP will be critically evaluated. A discussion of recent advances in our knowledge about AP risk factors is also included.

The role of trypsin, trypsin inhibitor, and trypsin receptor in the onset and aggravation of pancreatitis

Trypsin activity is properly suppressed in the pancreatic acinar cells under normal conditions. A small amount of trypsinogen is converted to active trypsin and inactivated by pancreatic secretory trypsin inhibitor (PSTI), thereby preventing damage to pancreatic acinar cells as a first line of defense. However, if trypsin activation (due to excessive stimulation of pancreatic acinar cells) exceeds the capacity of PSTI, a subsequent cascade of events leads to the activation of various proteases that damage cells. This can be interpreted as the main causative event of pancreatitis onset. Trypsin produced in and secreted from the pancreatic acinar cells activates protease activated receptor-2 (PAR-2), which is present at high densities on the luminal surfaces of pancreatic acinar cells and duct cells. Results of PAR-2 activation are the production of cytokines and the regulation of exocrine function via a negative feedback loop. Thus, the actions of trypsin, trypsin inhibitor (PSTI), and trypsin receptor (PAR-2) in the pancreas are strongly interconnected.

Review of experimental animal models of acute pancreatitis

The underlying mechanisms involved in the pathogenesis of acute pancreatitis are ill understood. The mortality rate of this disease has not significantly improved over the past few decades. Current treatment options are limited, and predominantly aimed at supportive therapy. A key feature of severe acute pancreatitis is the presence of extensive tissue necrosis with both local and systemic manifestations of inflammatory response syndromes. A better understanding of the underlying pathophysiology of severe acute pancreatitis may lead to more targeted therapeutic options, potentially leading to improved survival. Animal models of acute pancreatitis are therefore an essential investigative tool for these aims to be achieved. This review discusses the suitability of recent non-invasive models of acute pancreatitis such as hormone-induced, alcohol-induced, immune-mediated, diet-induced, gene knockout and L-arginine; and invasive models including closed duodenal loop, antegrade pancreatic duct perfusion, biliopancreatic duct injection, combination of secretory hyperstimulation with minimal intraductal bile acid exposure, vascular-induced, ischaemia/reperfusion and duct ligation.

Effect of herpesvirus infection on pancreatic duct cell secretion

AIM: To examine the effect of acute infection caused by herpesvirus (pseudorabies virus, PRV) on pancreatic ductal secretion.

METHODS: The virulent Ba-DupGreen (BDG) and non-virulent Ka-RREp0lacgfp (KEG) genetically modified strains of PRV were used in this study and both of them contain the gene for green fluorescent protein (GFP). Small intra/interlobular ducts were infected with BDG virus (107 PFU/mL for 6 h) or with KEG virus (1010 PFU/mL for 6 h), while non-infected ducts were incubated only with the culture media. The ducts were then cultured for a further 18 h. The rate of HCO3- secretion [base efflux -J(B-)] was determined from the buffering capacity of the cells and the initial rate of intracellular acidification (1) after sudden blockage of basolateral base loaders with dihydro-4,4-diisothiocyanatostilbene-2,2-disulfonic acid (500 mmol/L) and amiloride (200 mmol/L), and (2) after alkali loading the ducts by exposure to NH4Cl. All the experiments were performed in HCO3--buffered Ringer solution at 37°C (n = 5 ducts for each experimental condition). Viral structural proteins were visualized by immunohistochemistry. Virally-encoded GFP and immunofluorescence signals were recorded by a confocal laser scanning microscope.

RESULTS: The BDG virus infected the majority of accessible cells of the duct as judged by the appearance of GFP and viral antigens in the ductal cells. KEG virus caused a similarly high efficiency of infection. After blockage of basolateral base loaders, BDG infection significantly elevated -J(B^-) 24 h after the infection, compared to the non-infected group. However, KEG infection did not modify -J(B^-). After alkali loading the ducts, -J(B^-) was significantly elevated in the BDG group compared to the control group 24 h after the infection. As we found with the inhibitor stop method, no change was observed in the group KEG compared to the non-infected group.

CONCLUSION: Incubation with the BDG or KEG strains of PRV results in an effective infection of ductal epithelial cells. The BDG strain of PRV, which is able to initiate a lytic viral cycle, stimulates HCO3- secretion in guinea pig pancreatic duct by about four- to fivefold, 24 h after the infection. However, the KEG strain of PRV, which can infect, but fails to replicate, has no effect on HCO3- secretion. We suggest that this response of pancreatic ducts to virulent PRV infection may represent a defense mechanism against invasive pathogens to avoid pancreatic injury.

Alcohol and pancreatic cancer

Findings obtained from numerous prospective cohort and case-control studies on alcohol consumption and pancreatic cancer risk have been inconsistent, with many confounding variables present in various investigations. However, heavy alcohol consumption has been known to be a major cause of chronic pancreatitis and a risk factor for type 2 diabetes mellitus, both of which are linked to pancreatic cancer. It has been established that an extensive normal interaction exists between the exocrine and endocrine pancreas, as well as in inflammatory processes and carcinogenesis. Alcohol and its metabolites (acetaldehyde and fatty acid ethyl esters) can alter metabolic pathways involved in the inflammatory response and carcinogenesis, and they are mediated by one or more of the following mechanisms: (1) premature activation of zymogens; (2) induction of the inflammatory response through activation of nuclear transcription factors, including nuclear factor-kappa and activation protein 1; (3) increased production of reactive oxygen species, resulting in oxidative DNA damage and altered effect of dietary antioxidants; (4) activation of pancreatic stellate cells, which leads to fibrosis; (5) gene mutation in enzymes related to cytochrome P450, glutathione S-transferase, aldehyde dehydrogenase, cationic trypsinogen, and pancreatic secretory trypsin inhibitor; (6) synergistic effects of ethanol and tobacco carcinogen on NNK [nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone] metabolism; and (7) dysregulation of proliferation and apoptosis. These various metabolic effects of alcohol can lead to or interact with other risk factors (genetic, dietary, environmental, and lifestyle factors) that result in acute and chronic pancreatitis and diabetes mellitus and, ultimately, affect the multistep process of carcinogenesis toward the development of pancreatic cancer.

The Influence of a load of L-arginine on serum amino acids and pancreatic apoptosis/proliferation and ATP levels in the rat

OBJECTIVES

Administration of high doses of amino acids like ethionine, methionine, and arginine causes pancreatic tissue damage. The initial mechanism behind these effects is not known. The aim of this study was to show the early effects of a load of L-arginine on programed cell death/proliferation and ATP levels in the pancreas.

METHODS

We analyzed in rats the effects of intraperitoneal administration of L-arginine on serum amino acids, pancreatic cell apoptosis/proliferation, and ATP levels at 8, 16, and 24 hours. Serum amino acid concentrations were measured with HPLC, tissue ATP was measured fluorometrically, apoptosis was studied with caspase-3 activity and histone-associated DNA-fragments, and proliferation was studied with thymidine autoradiography.

RESULTS

After a load of l-arginine, there were initially increased serum levels of L-arginine and L-citrulline, but these fell below control levels after 24 hours as well as amino acids in the glutamate family (ornithine, proline, histidine, and glutamine). Initially, increased ATP levels in the pancreatic tissue returned to control levels at 24 hours. The acinar cells proliferation was suppressed and the apoptosis rate strongly increased at 16 and 24 hours. Pancreatic histology showed vacuole formation in the acinar cells at 8 hours. At 16 hours, there was less vacuolization, but apoptotic bodies were seen, and at 24 hours there was cell degeneration but no necrosis.

CONCLUSIONS

After a load of l-arginine, amino acid metabolism causes a high ATP production in the pancreatic tissue that may cause mitochondrial initiation of cell death.