No description available.

Introducción: Los pólipos gástricos adenomatosos son poco frecuentes y generalmente se encuentran en el examen endoscópico de rutina. La intususcepción gastroduodenal es una com- plicación poco frecuente de los pólipos gástricos y ha sido raramente descrita como una causa de pancreatitis aguda. Caso clínico: Presentamos el caso de un varón de 68 anos ̃ el cual ingresa de urgencia con dolor abdominal, náuseas y vómitos catalogados en un inicio como pancreatitis aguda de etiología biliar; incidentalmente se descubre un pólipo gástrico pediculado intususceptado a duodeno como causa de la pancreatitis aguda. Se realizó tratamiento endoscópico de urgencia y trata- miento definitivo con cirugía abierta.

Introduction: Derangement of systemic and mucosal immunity, which are the integral components of the immune system, increases the risk of septic complications in patients postoperatively. The aims of this study were to investigate the integrity of systemic immunity as well as the mucosal immune system in patients with pancreatic cancer (PC), chronic pancreatitis (CP) and obstructive jaundice (OJ).Method: Healthy controls, as well as four groups of patients were studied. These included; jaundiced patients with PC, jaundiced patients secondary to benign disease (choledocholithiasis), non-jaundiced patients with PC and non-jaundiced patients with CP. The study evaluated the nutritional status including anthropometric measurements and the serum proteins: retinal binding protein (RBP), transferrin (TRF) and prealbumin (PALB). This study also evaluated systemic immunity in terms of total lymphocyte count, lymphocyte subsets (CD4+, CD8+, CD25+and CD56+), tumour necrosis factor alpha (TNF- alpha), interleukin-1alpha (IL-1 alpha) and complement components; and mucosal immunity in terms of CD3+, CD4+, CD8+, CD20+, CD57+, CD68+ and mast cells. Results: 78 patients were recruited (including 39 males) as follows: normal controls (n=17), benign OJ (n=9), patients with PC with jaundice (n=23), non-jaundiced patients with PC (n=20) and CP (n=9). Circulating CD25+ and CD4+ were significantly lower in the PC group whereas CD8+ showed increased levels in the same patients with a significant decrease in OJ patients when compared with controls. Circulating CD56+ showed no statistically significant difference between all four groups. In addition, IL-1 and TNF-alpha showed no statistically significant difference in all groups when compared with the control group. Also, C3 and CH50 showed significantly raised levels in PC with jaundice when compared with the control group. On the other hand mucosal lymphocyte subsets showed no statistically significant difference among all groups in comparison with the control group. As for prealbumin and transferrin, both showed significantly low levels in OJ, PC with jaundice and with PC when compared to healthy controls. Survival analysis for both PC groups was carried out and showed no difference in terms of age, however PC patients who survived over 13 months showed increased levels of prealbumin as well as low levels of CH50.Conclusion: Patients with PC both with and without jaundice showed some signs of altered and dysfunctional systemic immunity as well as a reduction in serum proteins. These findings may have implications on the disease progression and postoperative complications. This may warrant therapeutic interventions to restore nutrition and improve immunity before major surgical intervention is planned which could result in improving prognosis.

Distinct membrane fusion events in the polarized pancreatic acinar cell involve highly specific interactions between distinct sets of SNARE proteins forming exocytotic complexes, whose assembly is modulated by distinct Munc18 proteins. The Munc18 isoform responsible for these exocytotic events in the acinar cell is unknown. Here, I postulate Munc18b to regulate apical exocytosis in the acinar cell. Current dogma for the pathogenesis of acute pancreatitis, including alcoholic pancreatitis, is mis-targeting and deregulated fusion of zymogen granules with lysosomal bodies in the acinar cells. This derangement results in premature activation of proteolytic zymogens and autophagic digestion of cellular contents. I have hypothesized an alternate mechanism, which is pathologic exocytosis occurring at the basolateral plasma membrane, and further propose Munc18c to mediate this process in alcoholic pancreatitis. The aims of this thesis are to demonstrate the roles of Munc18b and Munc18c in regulated apical exocytosis and pathologic basolateral exocytosis underling alcoholic pancreatitis, respectively. In Chapter Three, using both real-time and static imaging techniques and biochemical tools, I demonstrated that Munc18c is dissociated from the acinar basal plasma membrane (BPM) when stimulated with postprandial CCK8 preceding preincubation of acini with postprandial 20-50mM ethanol concentrations. This activated Syntaxin (Syn)-4 and SNAP-23 on the BPM to complex with VAMP proteins on the granule to form the exocytotic SNARE complex that triggered basolateral exocytosis. This molecular mechanism of pathologic basolateral exocytosis was recapitulated in an Ethanol-diet rat model of pancreatitis. In Chapter Four, I determined Munc18b to be in the apical pole of the acinar cell to appropriately bind cognate Syn-2 and Syn-3 in the apical PM and ZGs. Here, I examined the structure-function of Munc18b on amylase secretion by employing Munc18b mutants with distinct affinities to Syn-2 and Syn-3. In Chapter Five, I discovered a novel EF-hand Ca2+-binding protein called Cab45b, which binds Munc18b to regulate its membrane targeting and interactions with Syntaxins in the acinar cell in a manner that influenced Ca2+-induced amylase release. Taken together, these studies clarify our understanding of the role of Munc18 proteins involved in regulated and pathologic membrane fusion events underlying physiologic digestive enzyme secretion and clinical alcoholic pancreatitis.

No description available.

Distinct membrane fusion events in the polarized pancreatic acinar cell involve highly specific interactions between distinct sets of SNARE proteins forming exocytotic complexes, whose assembly is modulated by distinct Munc18 proteins. The Munc18 isoform responsible for these exocytotic events in the acinar cell is unknown. Here, I postulate Munc18b to regulate apical exocytosis in the acinar cell. Current dogma for the pathogenesis of acute pancreatitis, including alcoholic pancreatitis, is mis-targeting and deregulated fusion of zymogen granules with lysosomal bodies in the acinar cells. This derangement results in premature activation of proteolytic zymogens and autophagic digestion of cellular contents. I have hypothesized an alternate mechanism, which is pathologic exocytosis occurring at the basolateral plasma membrane, and further propose Munc18c to mediate this process in alcoholic pancreatitis. The aims of this thesis are to demonstrate the roles of Munc18b and Munc18c in regulated apical exocytosis and pathologic basolateral exocytosis underling alcoholic pancreatitis, respectively. In Chapter Three, using both real-time and static imaging techniques and biochemical tools, I demonstrated that Munc18c is dissociated from the acinar basal plasma membrane (BPM) when stimulated with postprandial CCK8 preceding preincubation of acini with postprandial 20-50mM ethanol concentrations. This activated Syntaxin (Syn)-4 and SNAP-23 on the BPM to complex with VAMP proteins on the granule to form the exocytotic SNARE complex that triggered basolateral exocytosis. This molecular mechanism of pathologic basolateral exocytosis was recapitulated in an Ethanol-diet rat model of pancreatitis. In Chapter Four, I determined Munc18b to be in the apical pole of the acinar cell to appropriately bind cognate Syn-2 and Syn-3 in the apical PM and ZGs. Here, I examined the structure-function of Munc18b on amylase secretion by employing Munc18b mutants with distinct affinities to Syn-2 and Syn-3. In Chapter Five, I discovered a novel EF-hand Ca2+-binding protein called Cab45b, which binds Munc18b to regulate its membrane targeting and interactions with Syntaxins in the acinar cell in a manner that influenced Ca2+-induced amylase release. Taken together, these studies clarify our understanding of the role of Munc18 proteins involved in regulated and pathologic membrane fusion events underlying physiologic digestive enzyme secretion and clinical alcoholic pancreatitis.

Ausgangslage: Die genetischen Grundlagen der chronischen Pankreatitis sind zum heutigen Zeitpunkt nur unzureichend erforscht. Mutationen im Gen des Serinprotease-Inhibitors Kazal Type 1 (SPINK1) und heterozygote Mutationen im CFTR-Gen wurden in zahlreichen Untersuchungen gehäuft bei Patienten mit chronischer Pankreatitis nachgewiesen. Methodik: Es wurden retrospektiv anhand der Daten der Pankcourse Studie (2004-2007) Untersuchungen bei Patienten mit chronischer Pankreatitis zur Häufigkeit von SPINK1- und CFTR-Mutationen sowie zum Manifestationszeitpunkt der Erkrankung durchgeführt. In Fall-Kontroll-Analysen wurde untersucht, ob sich Unterschiede in den jeweiligen Krankheitsverläufen nachweisen lassen. Ergebnisse: Eine heterozygote SPINK1-Mutation (N34S) konnte bei 11,5% und eine CFTR-Mutationen bei 24% der untersuchten Patienten nachgewiesen werden. Bei Patienten mit SPINK1-Mutation fand sich im Gegensatz zu Patienten mit CFTR-Mutation eine signifikant frühere Krankheitsmanifestation als bei Patienten ohne Mutationsnachweis. Patienten mit SPINK1-Mutation mussten zudem seltener und später operiert werden als Patienten ohne Mutation. Bei Patienten mit CFTR-Mutation zeigte sich ein signifikant früheres Auftreten von Stenosierungen und Konkrementen des D. pancreaticus im Vergleich zur Kontrollgruppe. Schlussfolgerung: Die ätiologische Bedeutung von SPINK1- und CFTR-Mutationen konnte bestätigt werden. Es fanden sich einzelne Hinweise auf einen durch die jeweilige Mutation verursachten charakteristischen Krankheitsverlauf, was durch weitergehende Untersuchungen bestätigt werden muss.

Die chronische Pankreatitis (CP) ist eine wiederkehrende, entzündliche Erkrankung des Pankreas. In den letzten Jahren wurden mehrere Kandidatengene, die zur Entstehung einer CP prädisponieren, identifiziert. Zu diesen Genen gehören PRSS1, PRSS2, SPINK1, CFTR und CTRC. Der Pathogenese der genetisch bedingten CP scheint dabei eine frühzeitige, intrapankreatische Aktivierung von Trypsin zugrunde zu liegen. Cathepsin B (CTSB), eine in Lysosomen vorkommenden Protease, ist in der Lage Trypsinogen zu aktivieren. Genetisch zeigte sich eine Assoziation der p.L26V Variante bei tropisch-kalzifizierender CP, welche bei idiopathischer CP nicht bestätigt wurde. Neben CTSB ist CTSL die am zweithäufigsten vorkommende lysosomale Protease. Funktionelle Untersuchungen zeigten, dass CTSL ein inaktives Trypsin freisetzt. Im Mausmodell zeigten sich bei Ctsl-/- Tieren bei experimentell induzierter Pankreatitis zwei Effekte. Zum einen war die Trypsinaktivität erhöht, zum anderen verlief die Pankreatitis milder, da vermehrt Apoptose anstelle von Nekrose der Azinuszellen auftrat. In dieser Studie wurde mittels uni-direktionaler DNA-Sequenzierung das gesamte CTSL1 untersucht. Dabei fanden wir insgesamt drei seltene nicht-synonyme Varianten. Die Variante c.5A>C (p.N2T, rs112682750) fanden wir bei einem Patienten, wobei diese Variante bereits bei Kontrollen beschrieben wurde. Die Varianten c.126+1G>A und c.915A>C (p.E305D) lagen bei jeweils einer Kontrolle vor. Sowohl seltene als auch häufige Varianten und die berechneten Haplotypen zeigten keinen signifikanten Verteilungsunterschied zwischen Patienten und Kontrollen. Demnach besteht keine Assoziation von Varianten des CTSL1 und CP.

No description available.

Human enteroviruses (HEVs), particularly Coxsackie B viruses (CVBs), might trigger the onset of type 1 diabetes (T1D), either by direct infection of the insulin-producing beta-cells or by an indirect inflammatory response. The overall aim of this thesis was to study the tropism of HEVs in isolated human pancreatic cell clusters in vitro including virus effects on islet function, gene-expression and ultrastructure. Furthermore, the expression of the major CVB-receptor, CAR, was investigated in pancreatic tissue from T1D-related subjects and CVB-infected islets. Also, tissues and isolated islets from two adult organ-donors who died close to disease onset were studied.The results showed that beta-cells were destroyed through lytic infections with different strains of CVBs and that islets function did not depend on replication per se but on the degree of islet destruction. Virus particles were observed in beta-cells in association with insulin granules, however no virus replication or particles could be observed in the exocrine cell clusters, as opposed to in mice models. The virus-infected islets had a decreased expression of insulin mRNA and CAR mRNA/protein, possibly reflecting virus-killed beta-cells. Infected beta-cells contained a high number of insulin granules, which might indicate an impaired function.The in vivo studies showed presence of virus proteins in the islets of both donors who died close to onset of T1D and elevated expression of innate immunity genes, potentially indicating viral infection, but direct evidence is lacking. Both donors were immune-reactive for insulin but the isolated islets had an impaired or completely lacking glucose response. Ultrastructural analysis showed both damaged beta-cells and normal-looking beta-cells, indicating that the latter might still have the potential to function but were blocked. CAR-expression was significantly increased in T1D-related subjects which might indicate tissue damage and/or inflammation in these subjects.To conclude, these results showed that CVBs could infect human primary beta-cells, likely by binding to CAR and lead to functional abnormalities, indicating that they could cause T1D in vivo. Exocrine cells were not permissive to CVB, which raises the question if mice-models should be used to study human pancreatitis. Also, unique materials from two T1D organ-donors were described.