International consensus guidelines for surgery and the timing of intervention in chronic pancreatitis.

BACKGROUND/OBJECTIVES: Chronic pancreatitis (CP) is a complex inflammatory disease with pain as the predominant symptom. Pain relief can be achieved using invasive interventions such as endoscopy and surgery. This paper is part of the international consensus guidelines on CP and presents the consensus guideline for surgery and timing of intervention in CP. METHODS: An international working group with 15 experts on CP surgery from the major pancreas societies (IAP, APA, JPS, and EPC) evaluated 20 statements generated from evidence on 5 questions deemed to be the most clinically relevant in CP. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available for each statement. To determine the level of agreement, the working group voted on the 20 statements for strength of agreement, using a nine-point Likert scale in order to calculate Cronbach's alpha reliability coefficient. RESULTS: Strong consensus was obtained for the following statements: Surgery in CP is indicated as treatment of intractable pain and local complications of adjacent organs, and in case of suspicion of malignant (cystic) lesion; Early surgery is favored over surgery in a more advanced stage of disease to achieve optimal long-term pain relief; In patients with an enlarged pancreatic head, a combined drainage and resection procedure, such as the Frey, Beger, and Berne procedure, may be the treatment of choice; Pancreaticoduodenectomy is the most suitable surgical option for patients with groove pancreatitis; The risk of pancreatic carcinoma in patients with CP is too low (2% in 10 year) to recommend active screening or prophylactic surgery; Patients with hereditary CP have such a high risk of pancreatic cancer that prophylactic resection can be considered (lifetime risk of 40-55%). Weak agreement for procedure choice in patients with dilated duct and normal size pancreatic head: both the extended lateral pancreaticojejunostomy and Frey procedure seems to provide equivalent pain control in patients. CONCLUSIONS: This international expert consensus guideline provides evidenced-based statements concerning key aspects in surgery and timing of intervention in CP. It is meant to guide clinical practitioners and surgeons in the treatment of patients with CP.

[International multidisciplinary classification of acute pancreatitis severity: the 2013 Spanish edition]. / Clasificación Internacional y Multidisciplinaria de la Pancreatitis Aguda: Edición Española 2013.

OBJECTIVE: To develop a new classification of acute pancreatitis severity on the basis of a sound conceptual framework, comprehensive review of the published evidence, and worldwide consultation. BACKGROUNDS: The Atlanta definitions of acute pancreatitis severity are ingrained in the lexicon of specialist in pancreatic diseases, but are suboptimal because these definitions are based on the empiric description of events not associated with severity. METHODS: A personal invitation to contribute to the development of a new classification of acute pancreatitis severity was sent to all surgeons, gastroenterologists, internists, intensivists and radiologists currently active in the field of clinical acute pancreatitis. The invitation was not limited to members of certain associations or residents of certain countries. A global web-based survey was conducted, and a dedicated international symposium was organized to bring contributors from different disciplines together and discuss the concept and definitions. RESULTS: The new classification of severity is based on the actual local and systemic determinants of severity, rather than on the description of events that are non-causally associated with severity. The local determinant relates to whether there is (peri) pancreatic necrosis or not, and if present, whether it is sterile or infected. The systemic determinant relates to whether there is organ failure or not, and if present, whether it is transient or persistent. The presence of one determinant can modify the effect of another, whereby the presence of both infected (peri) pancreatic necrosis and persistent organ failure has a greater impact upon severity than either determinant alone. The derivation of a classification based on the above principles results in four categories of severity: mild, moderate, severe, and critical. CONCLUSIONS: This classification is the result of a consultative process among specialists in pancreatic diseases from 49 countries spanning North America, South America, Europe, Asia, Oceania and Africa. It provides a set of concise up to date definitions of all the main entities pertinent to classifying the severity of acute pancreatitis in clinical practice and research. This ensures that the determinant-based classification can be used in a uniform manner throughout the world.

[Determinant-based classification of acute pancreatitis severity. International multidisciplinary classification of acute pancreatitis severity: the 2013 German edition]. / Einteilung des Schweregrads der akuten Pankreatitis. Internationale, multidisziplinäre klinische Klassifikation auf Basis pathogenetischer Determinanten: Deutsche Version 2013.

OBJECTIVE: The aim of this study was to develop a new international classification of acute pancreatitis severity on the basis of a sound conceptual framework, comprehensive review of published evidence, and worldwide consultation. BACKGROUND: The Atlanta definitions of acute pancreatitis severity are ingrained in the lexicon of pancreatologists but suboptimal because these definitions are based on empiric descriptions of occurrences that are merely associated with severity. METHODS: A personal invitation to contribute to the development of a new international classification of acute pancreatitis severity was sent to all surgeons, gastroenterologists, internists, intensive medicine specialists, and radiologists who are currently active in clinical research on acute pancreatitis. The invitation was not limited to members of certain associations or residents of certain countries. A global Web-based survey was conducted and a dedicated international symposium was organised to bring contributors from different disciplines together and discuss the concept and definitions. RESULT: The new international classification is based on the actual local and systemic determinants of severity, rather than descriptions of events that are correlated with severity. The local determinant relates to whether there is (peri)pancreatic necrosis or not, and if present, whether it is sterile or infected. The systemic determinant relates to whether there is organ failure or not, and if present, whether it is transient or persistent. The presence of one determinant can modify the effect of another such that the presence of both infected (peri)pancreatic necrosis and persistent organ failure have a greater effect on severity than either determinant alone. The derivation of a classification based on the above principles results in 4 categories of severity - mild, moderate, severe, and critical. CONCLUSIONS: This classification is the result of a consultative process amongst pancreatologists from 49 countries spanning North America, South America, Europe, Asia, Oceania, and Africa. It provides a set of concise up-to-date definitions of all the main entities pertinent to classifying the severity of acute pancreatitis in clinical practice and research. This ensures that the determinant-based classification can be used in a uniform manner throughout the world.

[Multidisciplinar international classification of the severity of acute pancreatitis: Italian version 2013]. / Classificazione Internazionale Multidisciplinare della Gravità della Pancreatite Acuta Versione Italiana 2013.

AIM: The aim of this paper was to present the 2013 Italian edition of a new international classification of acute pancreatitis severity. The Atlanta definitions of acute pancreatitis severity are ingrained in the lexicon of pancreatologists but suboptimal because these definitions are based on empiric description of occurrences that are merely associated with severity. METHODS: A personal invitation to contribute to the development of a new international classification of acute pancreatitis severity was sent to all surgeons, gastroenterologists, internists, intensivists, and radiologists who are currently active in clinical research on acute pancreatitis. A global web-based survey was conducted and a dedicated international symposium was organized to bring contributors from different disciplines together and discuss the concept and definitions. RESULTS: The new international classification is based on the actual local and systemic determinants of severity, rather than description of events that are correlated with severity. The local determinant relates to whether there is (peri)pancreatic necrosis or not, and if present, whether it is sterile or infected. The systemic determinant relates to whether there is organ failure or not, and if present, whether it is transient or persistent. The presence of one determinant can modify the effect of another such that the presence of both infected (peri)pancreatic necrosis and persistent organ failure have a greater effect on severity than either determinant alone. The derivation of a classification based on the above principles results in 4 categories of severity-mild, moderate, severe, and critical. CONCLUSION: This classification provides a set of concise up-to-date definitions of all the main entities pertinent to classifying the severity of acute pancreatitis in clinical practice and research.

Hereditary pancreatitis is caused by a mutation in the cationic trypsinogen gene.

Hereditary pancreatitis (HP) is a rare, early-onset genetic disorder characterized by epigastric pain and often more serious complications. We now report that an Arg-His substitution at residue 117 of the cationic trypsinogen gene is associated with the HP phenotype. This mutation was observed in all HP affected individuals and obligate carriers from five kindreds, but not in individuals who married into the families nor in 140 unrelated individuals. X-ray crystal structure analysis, molecular modelling, and protein digest data indicate that the Arg 117 residue is a trypsin-sensitive site. Cleavage at this site is probably part of a fail-safe mechanism by which trypsin, which is activated within the pancreas, may be inactivated; loss of this cleavage site would permit autodigestion resulting in pancreatitis.

Genetics of pancreatitis with a focus on the pancreatic ducts.

Genetic risk for acute pancreatitis (AP), recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) are increasingly recognized. The exocrine pancreas is composed of both acinar cells and duct cells, with genetic factors associated with AP, RAP and CP linked to one cell type or the other. Increased susceptibility to pancreatitis occurs when the normal physiological mechanisms that allow the pancreas to respond to common stresses or injury are altered. Currently, most our knowledge about genetics focuses on three genes that play critical roles in pancreatic function (PRSS1, CFTR, SPINK1) such that isolated defects lead to disease. However, recent data suggest that more complex combination of genetic and environmental factors are also as important, or more important than Mendelian genetic risk. Understanding of complex interactions requires modeling of these factors so that the response to stresses or injury can be simulated and critical interactions understood. A simple duct cell model is given to illustration the relationship between CFTR, CASR, aquaporins, claudins, and SPINK1, and how they interact. The role of CFTR variants in pancreatic diseases is then discussed.

Physiology: does gut hormone PYY3-36 decrease food intake in rodents?

Batterham et al. report that the gut peptide hormone PYY3-36 decreases food intake and body-weight gain in rodents, a discovery that has been heralded as potentially offering a new therapy for obesity. However, we have been unable to replicate their results. Although the reasons for this discrepancy remain undetermined, an effective anti-obesity drug ultimately must produce its effects across a range of situations. The fact that the findings of Batterham et al. cannot easily be replicated calls into question the potential value of an anti-obesity approach that is based on administration of PYY3-36.

Obesity and the risk of severe acute pancreatitis.

Acute pancreatitis is an acute inflammatory response to pancreatic injury. In humans, the magnitude of the response and complications are highly variable and unpredictable. Recent clinical studies demonstrate that all major complications are more common and more severe in patients who are obese. This raises the question of how adipose tissue interacts with the immune response to worsen the severity of acute pancreatitis. Here we review the results of a series of new studies focusing on various fat-associated cytokines (adipokines) that are produced and released in proportion to the amount of visceral adipose tissue in the body. The primary adipokines that have been studied in acute pancreatitis include adiponectin, leptin, visfatin, resistin, and adipose tissue related MCP-1, TNF-a and IL-6. These new data provide strong evidence that susceptibility and severity in acute pancreatitis are associated with a number of these adipokines. Although no specific therapy exists to block the effects of these factors, recognizing the high risk and anticipating inflammation-associated complications of adipokine release is an important part of optimal patient management. For this review, a PubMed search was performed with the terms "acute pancreatitis", "severe acute pancreatitis", and "obesity". Additional searches were conducted to identify recent reviews on adipokines, Finally, PubMed searches on specific adipokines, including adiponectin, leptin, visfatin and resistin were conducted focusing on acute pancreatitis and systemic inflammation.

Surveillance for pancreatic cancer in high-risk individuals.

Background: Surveillance of individuals at high risk of pancreatic ductal adenocarcinoma (PDAC) and its precursors might lead to better outcomes. The aim of this study was to determine the prevalence and outcomes of PDAC and high-risk neoplastic precursor lesions among such patients participating in surveillance programmes. Methods: A multicentre study was conducted through the International CAncer of the Pancreas Screening (CAPS) Consortium Registry to identify high-risk individuals who had undergone pancreatic resection or progressed to advanced PDAC while under surveillance. High-risk neoplastic precursor lesions were defined as: pancreatic intraepithelial neoplasia (PanIN) 3, intraductal papillary mucinous neoplasia (IPMN) with high-grade dysplasia, and pancreatic neuroendocrine tumours at least 2 cm in diameter. Results: Of 76 high-risk individuals identified in 11 surveillance programmes, 71 had undergone surgery and five had been diagnosed with inoperable PDAC. Of the 71 patients who underwent resection, 32 (45 per cent) had PDAC or a high-risk precursor (19 PDAC, 4 main-duct IPMN, 4 branch-duct IPMN, 5 PanIN-3); the other 39 patients had lesions thought to be associated with a lower risk of neoplastic progression. Age at least 65 years, female sex, carriage of a gene mutation and location of a lesion in the head/uncinate region were associated with high-risk precursor lesions or PDAC. The survival of high-risk individuals with low-risk neoplastic lesions did not differ from that in those with high-risk precursor lesions. Survival was worse among patients with PDAC. There was no surgery-related mortality. Conclusion: A high proportion of high-risk individuals who had surgical resection for screening- or surveillance-detected pancreatic lesions had a high-risk neoplastic precursor lesion or PDAC at the time of surgery. Survival was better in high-risk individuals who had either low- or high-risk neoplastic precursor lesions compared with that in patients who developed PDAC.

Antecedentes: Se podrían obtener mejores resultados con el seguimiento de individuos de alto riesgo para adenocarcinoma ductal pancreático (pancreatic ductal adenocarcinoma, PDAC) y lesiones precursoras. El objetivo de este estudio fue determinar la prevalencia y los resultados del PDAC y de las lesiones precursoras de alto riesgo neoplásico en pacientes que participaron en programas de seguimiento. Métodos: Se llevó a cabo un estudio multicéntrico a través del registro internacional del consorcio CAPS (Common Automotive Platform Standard) para identificar a las personas de alto riesgo que se habían sometido a una resección pancreática o habían progresado a PDAC avanzado mientras estaban en seguimiento. Se definieron como lesiones neoplásicas precursoras de alto riesgo la neoplasia intraepitelial pancreática de tipo 3 (PanIN­3), la neoplasia papilar mucinosa intraductal (intraductal papillary mucinous neoplasia, IPMN) con displasia de alto grado y los tumores neuroendocrinos pancreáticos (pancreatic neuroendocrine tumours, PanNET) de ≥ 2 cm de diámetro. Resultados: De 76 individuos con lesiones de alto riesgo identificados en 11 programas de seguimiento, 71 fueron tratados quirúrgicamente y 5 fueron diagnosticados de un PDAC inoperable. De las 71 resecciones, 32 (45%) tenían PDAC o una lesión precursora de alto riesgo (19 PDAC, 4 IPMN de conducto principal, 4 IPMN de rama secundaria y 5 PanIN­3). Los otros 39 pacientes tenían lesiones que se consideraron asociadas con un menor riesgo de progresión neoplásica. La edad ≥ 65 años, el sexo femenino, el ser portador de una mutación genética y la localización de la lesión en la cabeza/proceso uncinado fueron factores asociados a las lesiones precursoras de alto riesgo o al PDAC. No hubo diferencias en la supervivencia de individuos de alto riesgo con lesiones neoplásicas de bajo riesgo frente a aquellos que presentaron lesiones precursoras de alto riesgo. La supervivencia fue peor en los pacientes con PDAC. No hubo mortalidad relacionada con la cirugía. Conclusión: Un elevado porcentaje de individuos de alto riesgo que se sometieron a resección quirúrgica tras la detección de lesiones pancreáticas en el seguimiento tenían una lesión precursora neoplásica de alto riesgo o un PDAC. La supervivencia fue mejor en individuos de alto riesgo que tenían lesiones precursoras neoplásicas de bajo o alto riesgo en comparación con aquellos pacientes que habían desarrollado un PDAC.

Serology in autoimmune pancreatitis.

Autoimmune pancreatitis (AIP) is the pancreatic manifestation of a systemic immune-driven, inflammatory process that can involve organs such as the bile duct, salivary glands and lymph nodes, in addition to the pancreas. Many of the presenting signs and symptoms of AIP, including painless jaundice, weight loss and mild epigastric pain, are characteristic of pancreatic adenocarcinoma; thus, obtaining an accurate diagnosis to avoid unnecessary surgery is imperative. AIP responds very well to steroid treatment, although it may recur in up to 20% to 40% of cases. The diagnostic criteria for AIP are histological, radiographic, clinical and laboratory-based in nature. Although no international consensus on diagnostic criteria has yet been made, some of the diagnostic features of AIP include elevated gamma globulin, immunoglobulin, and, in particular, immunoglobulin G4 fraction (IgG4). The search for a distinct serological marker of AIP has included antibodies to a wide range of antigenic stimuli. To date, there have been studies of AIP and antibodies to lactoferrin, carbonic anhydrase isoforms II and IV, pancreatic secretory trypsin inhibitor (PSTI or SPINK) as well as to less sensitive or specific markers of autoimmunity, such as antinuclear antibody and rheumatoid factor. Although there are some preliminary strengths of association with PSTI antibodies, none of these biomarkers appears to be sensitive or specific enough to serve as distinctive evidence of AIP. At the current time, elevations of IgG4 to greater than 280 mg/dL remain the most reliable and reproducible indicator that a patient has AIP.

Marked QRS complex abnormalities and sodium channel blockade by propoxyphene reversed with lidocaine.

The opiate analgesic propoxyphene produces cardiac toxicity when taken in overdose. We recently observed a patient with propoxyphene overdose in whom marked QRS widening was reversed by lidocaine. The reversal is apparently paradoxical as both agents block the inward sodium current (INa). We examined possible mechanisms of the reversal by measuring INa in rabbit atrial myocytes during exposure to propoxyphene and the combination of propoxyphene and lidocaine (60 and 80 microM, respectively). Propoxyphene caused use-dependent block of INa during pulse train stimulation. Block recovered slowly with time constants of 20.8 +/- 3.9 s. Block during lidocaine exposure recovered with time constants of 2-3 s. During exposure to the mixture, block recovered as a double exponential. The half time for recovery during exposure to the mixture was 1.6 +/- .9 s compared with a half-time of 14.3 +/- 2.9 s during exposure to propoxyphene alone. During pulse train stimulation, less steady-state block was observed during exposure to the mixture than during exposure to propoxyphene alone when the interval between pulses was greater than 0.95 s. Both drugs compete for a common receptor during the polarizing phase. The more rapid dissociation of lidocaine during the recovery period leads to less block during the mixture than during exposure to propoxyphene alone. The experiments suggest a mechanism for reversal of the cardiac toxicity of drugs which have slow unbinding kinetics.

Hereditary pancreatitis and the risk of pancreatic cancer. International Hereditary Pancreatitis Study Group.

BACKGROUND: Hereditary pancreatitis is an autosomal-dominant disease, with a variable expression and an estimated penetrance of 80%. The gene for this disease has recently been mapped to chromosome 7q35, and the defect is believed to be caused by a mutation in the cationic trypsinogen gene. Acute attacks of abdominal pain begin early in life and the disease often progresses to chronic pancreatitis. Although the risk of pancreatic cancer is thought to be increased in more common types of chronic pancreatitis, the frequency of pancreatic cancer in the inherited type of pancreatitis is uncertain. PURPOSE: The aim of this study was to assess the frequency of pancreatic cancer and other tumors in patients with hereditary form of pancreatitis. METHODS: To determine the natural history of hereditary pancreatitis, we invited all members of the American Pancreatic Association and the International Association of Pancreatology to participate in a longitudinal study of this rare form of pancreatitis. The initial criteria for patient eligibility were as follows: early age (< or = 30 years) at onset of symptoms, positive family history, and absence of other causes. From April 1995 through February 1996, 37 physicians from 10 countries contributed medical records of 246 (125 males and 121 females) patients thought to have hereditary pancreatitis as the most likely diagnosis. This group included 218 patients where the diagnosis appeared to be highly probable and 28 additional patients where the diagnosis of hereditary pancreatitis was less certain: 25 patients who had relatively late onset of disease and a positive family history and three patients with onset of disease before age 30 years but with an uncertain family history. We reviewed all causes of death and compared the observed to the expected frequency of cancer in this historical cohort of patients with hereditary pancreatitis. The strength of the association between pancreatitis and pancreatic cancer was estimated by the standardized incidence ratio (SIR), which is the ratio of observed pancreatic cancer cases in the cohort to the expected pancreatic cancers in the background population, adjusted for age, sex, and country. RESULTS: The mean age (+/- standard deviation [SD]) at onset of symptoms of pancreatitis was 13.9 +/- 12.2 years. Compared with an expected number of 0.150, eight pancreatic adenocarcinomas developed (mean age +/- SD at diagnosis of pancreatic cancer: 56.9 +/- 11.2 years) during 8531 person-years of follow-up, yielding an SIR of 53 (95% confidence interval [CI] = 23-105). The frequency of other tumors was not increased: SIR = 0.7 (95% CI = 0.3-1.6). Eight of 20 reported deaths in the cohort were from pancreatic cancer. Thirty members of the cohort have already been tested for the defective hereditary pancreatitis gene: all 30 carry a mutated copy of the trypsinogen gene. The transmission pattern of hereditary pancreatitis was known for 168 of 238 patients without pancreatic cancer and six of eight with pancreatic cancer. Ninety-nine of the 238 patients without pancreatic cancer and six of the patients with pancreatic cancer inherited the disease through the paternal side of the family. The estimated cumulative risk of pancreatic cancer to age 70 years in patients with hereditary pancreatitis approaches 40%. For patients with a paternal inheritance pattern, the cumulative risk of pancreatic cancer is approximately 75%. CONCLUSIONS: Patients with hereditary pancreatitis have a high risk of pancreatic cancer several decades after the initial onset of pancreatitis. A paternal inheritance pattern increases the probability of developing pancreatic cancer.

PYY3-36 as an anti-obesity drug target.

The neuropeptide Y (NPY)/peptide YY (PYY) system has been implicated in the physiology of obesity for several decades. More recently ignited enormous interest in PYY3-36, an endogenous Y2-receptor agonist, as a promising anti-obesity compound. Despite this interest, there have been remarkably few subsequent reports reproducing or extending the initial findings, while at the same time studies finding no anti-obesity effects have surfaced. Out of 41 different rodent studies conducted (in 16 independent labs worldwide), 33 (83%) were unable to reproduce the reported effects and obtained no change or sometimes increased food intake, despite use of the same experimental conditions (i.e. adaptation protocols, routes of drug administration and doses, rodent strains, diets, drug vendors, light cycles, room temperatures). Among studies by authors in the original study, procedural caveats are reported under which positive effects may be obtained. Currently, data speak against a sustained decrease in food intake, body fat, or body weight gain following PYY3-36 administration and make the previously suggested role of the hypothalamic melanocortin system unlikely as is the existence of PYY deficiency in human obesity. We review the studies that are in the public domain which support or challenge PYY3-36 as a potential anti-obesity target.

'Diaphragmlike' stricture and ulcer of the colon during diclofenac treatment.

Diclofenac sodium is a widely used enteric-coated nonsteroidal anti-inflammatory drug. We describe a woman with Hemoccult-positive stools and iron deficiency anemia who developed both a colonic ulcer and a "diaphragm-like" colonic stricture while taking enteric-coated diclofenac. These lesions were evident on colonoscopy but not on barium studies. Biopsy specimens of the ulcer and stricture revealed particulate matter that was indistinguishable from diclofenac pill fragments by electron microscopy. Discontinuation of diclofenac therapy resulted in resolution of anemia and Hemoccult-positive stools. We conclude that (1) enteric-coated diclofenac is associated with both colonic ulcers and diaphragm-like colonic strictures; (2) the pathophysiologic mechanism for the development of both ulcers and strictures may involve a direct action of diclofenac within these lesions; (3) colonoscopy may be superior to barium studies in evaluating patients receiving diclofenac who have iron deficiency anemia and/or Hemoccult-positive stools.

Rat mitochondrial ATP synthase ATP5G3: cloning and upregulation in pancreas after chronic ethanol feeding.

Individuals with chronic excessive alcohol ingestion are put at the risk of acute and chronic pancreatitis. Underlying molecular mechanisms are unknown. Differential gene expression in the pancreas was profiled using mRNA differential display by comparison between control and ethanol-consuming rats. Male Wistar rats were fed with diets containing 6.7% (vol/vol) ethanol for 4 wk. A cDNA tag that was overexpressed in the pancreas of rats fed ethanol was isolated. A 723-bp cDNA was cloned from a rat pancreatic cDNA library, which encodes a novel rat mitochondrial ATP synthase subunit 9, isoform 3 (ATP5G3), which is homologous to a human ATP5G3 gene. Real-time PCR demonstrated that all three nuclear gene isoforms (ATP5G1, ATP5G2, and ATP5G3) were consistently upregulated in the pancreas of alcohol-consuming rats, parallel with mitochondrial injury. The cellular response to mitochondrial damage and metabolic stress may reflect an adaptive process for mitochondrial repair in pancreatic acinar cells during chronic ethanol ingestion.

Results of high dose intravenous urokinase for acute myocardial infarction.

To determine the outcome of patients after treatment with high-dose intravenous urokinase (3 million U) 102 patients were prospectively evaluated in the setting of acute myocardial infarction. The first 61 patients received intravenous urokinase as a continuous infusion and the last 41 patients were treated with an initial 1.5 million U intravenous bolus. Sixty-two percent of all patients had patent infarct-related arteries by the time of immediate angiography (median time 2.2 hours), which was performed in all patients. There was no significant difference in patency rates between patients treated with or without an initial intravenous bolus. Twenty-eight (28%) patients developed clinical evidence of recurrent ischemia (death, reocclusion, emergency angioplasty, urgent bypass surgery) during hospitalization, whereas only 7 (7%) developed angiographically documented reocclusion. Of 28 patients who failed to achieve successful reperfusion at the time of immediate catheterization, rescue angioplasty was technically successful in establishing reperfusion in all but 1 patient. No significant improvement in median global left ventricular function was seen between immediate (48%) and follow-up catheterization (48%). Significant bleeding complications were unusual except in 1 patient who experienced an intracranial hemorrhage. Eight (8%) patients died during hospitalization. Therefore, the use of high-dose intravenous urokinase in patients with acute myocardial infarction is associated with a 62% patency rate, a low incidence of reocclusion and bleeding complications and a high technical success rate with rescue angioplasty at the time of immediate catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Hereditary pancreatitis and pancreatic carcinoma.

Few risk factors for pancreatic cancer have emerged except for chronic pancreatitis. Recently, hereditary pancreatitis was estimated to carry a standardized incidence ratio of 53, a risk about 25 times higher than smoking. A review of the ongoing hereditary pancreatitis study of the Midwest Multicenter Pancreatic Study Group suggests that the risk of pancreatic cancer is related to long-standing pancreatitis rather than to the cationic trypsinogen mutations. No recommendations can be made on screening patients with hereditary pancreatitis for pancreatic cancer at this time. However, prospective data, serum, and pancreatic juice should be collected and banked on consenting patients at risk as part of prospective, multicenter trials so that evidence-based recommendations for hereditary pancreatitis and other types of chronic pancreatitis can be made in the future.

Electron microscope characterization of AgBr heterojunctions with silver carboxylates and their influence on the morphology of developed silver particles in thermally developed photomaterials.

Silver halide crystals formed during in situ treatment of silver stearate crystals with various halidizing agents are observed by scanning and transmission electron microscopy to form on the lateral edges of the silver carboxylate crystals. The location of the silver halide phase on the crystal edge is dictated by the anisotropic structure of the silver stearate crystal lattice, specifically, the layered structure in which silver ion layers are separated by long-chain hydrocarbon groups. The formation of AgBr on the lateral faces of these crystals is proposed to be typical not only of the formation of silver halide on silver stearate but also for all silver carboxylates of the general formula [AgCnH2(n-1)O2]2 when the crystals of these silver carboxylates have anisotropic, layered structures. The silver bromide/silver carboxylate heterojunction in an in situ system has been clearly observed by transmission electron microscopy. The heterojunction is comprised of a distorted silver carboxylate lattice, which accommodates the misalignment between the AgBr and [Ag(O2CR)]2 crystal lattices. The nature of heterojunction between the AgBr and the silver carboxylate when the AgBr is prepared separately from the preparation of the silver carboxylate differs from the in situ heterojunction. In this case, a layered compound, proposed to have a Ag1-xNaxSt composition, forms between the AgBr and the silver stearate which is a unique feature of this interface. The differences in the structure of interfaces formed between the silver halide and the silver fatty acid complex result in different silver particle morphologies during thermal development of exposed photothermographic films. The developed silver is generally filamentary when the photothermographic material contains silver halide prepared by the in situ exchange reaction between silver carboxylate and a brominating agent. If the photothermographic material is prepared from previously synthesized silver halide crystals, the preformed AgBr route, the developed silver generally crystallizes as dendritic crystals.

The area postrema lesions alter the inhibitory effects of peripherally infused pancreatic polypeptide on pancreatic secretion.

Circulating PP binds to specific receptors in the DVC through the AP, but the mechanism through which these brain receptors affect pancreatic secretion is not clear. We hypothesize that the removal of the AP (APX) will alter the effects of PP on pancreatic secretion. APX or sham procedures were performed in anesthetized male Wistar rats. After a 1-month recovery, one group of rats were infused with either PP (30 or 100 pmol/kg per h) or vehicle under basal or 2-DG-stimulated (75 mg/kg, i.v. bolus) conditions for studying pancreatic exocrine secretion. A second parallel group was sacrificed for examination of PP receptor binding in the brain stem. A third group received an intraperitoneal injection of PP at the dose of 4.15x10(4) pmol/kg (200 microg/kg) and c-fos expression in the brain stem was examined. APX eliminated PP binding sites in the DVC as assessed by autoradiography. PP infusion caused a dose-dependent decrease in basal protein secretion. APX partially reversed PP inhibition of basal protein secretion when infused at 30 pmol/kg per h, and at 100 pmol/kg per h stimulated pancreatic fluid secretion and reversed the inhibition of protein secretion. During 2-DG stimulation the effects of PP and 2-DG on pancreatic fluid and protein secretion were parallel. PP dose-dependently inhibited 2-DG-stimulated secretion in sham rats. APX reduced the pancreatic fluid (54%) and protein (46%) secretory response to 2-DG. However, PP at 30 pmol/kg per h remained a potent inhibitor of 2-DG-stimulated pancreatic secretion in APX rats. This effect was blunted with PP at 100 pmol/kg per h in APX rats, possibly related to the stimulatory effect of high-dose PP in APX rats without 2-DG. Furthermore, i.p. PP induced significantly greater c-fos activation of NTS neurons in APX rats than sham rats, despite the apparent absence of PP binding sites in the DVC. We conclude that in awake rats, PP inhibits basal secretion, in part, through the AP. Furthermore, and unlike PYY, PP inhibits 2-DG-stimulated pancreatic secretion, and it does so through an AP-independent mechanism. The possibility that the mechanism may involve the DVC cannot be excluded since i.p. injection of PP activates c-fos expression in DVC neurons. Thus, PP and PYY may regulate different components of the pancreatic secretory control system through unique pathways.

Distribution of pancreatic polypeptide receptors in the rat brain.

Pancreatic polypeptide (PP) is a regulatory peptide that modulates gastrointestinal function. Previously we demonstrated PP receptors in the brainstem and interpeduncular nucleus, and the PP receptors in the brainstem appear to modulate gastric motility and pancreatic exocrine secretion. The purpose of this study is to extend our understanding of the distribution of PP receptors in the rat brain in order to determine the systems that are potentially modulated by PP. Rat brains were studied using 125I-PP receptor autoradiography on cryostat sections of the entire brain cut in three planes (horizontal, sagittal, and coronal). Brain regions exhibiting PP binding sites were confirmed when identified in all three planes of section. Saturable PP binding was identified in the hypothalamus (arcuate and paraventricular n), the rostral forebrain (medial preoptic area, anterior olfactory nucleus, islands of Calleja, the dorsal endopiriform n, piriform cortex, and the bed n of the stria terminalis), medial amygdaloid n; the thalamus (anteromedial thal. n; reuniens thal. n; and paraventricular thal n), the interpeduncular red nucleus, substantia nigra, parabrachial n; locus coeruleus, mesencephalic trigeminal n, dorsal motor n of the vagus, the n solitary tract, and the area postrema. We conclude that PP receptors are distributed widely throughout the rat brain. The distribution of many of these PP binding sites corresponds to brain regions regulating digestion and autonomic function. We speculate, based on the patterns of binding in the olfactory and limbic systems, that PP receptors might be involved in positive reinforcement of ingestion behavioral as well as modulation of gastrointestinal function.