Avalanches during epithelial tissue growth; Uniform Growth and a drosophila eye disc model.

Epithelial tissues constitute an exotic type of active matter with non-linear properties reminiscent of amorphous materials. In the context of a proliferating epithelium, modeled by the quasistatic vertex model, we identify novel discrete tissue scale rearrangements, i.e. cellular rearrangement avalanches, which are a form of collective cell movement. During the avalanches, the vast majority of cells retain their neighbors, and the resulting cellular trajectories are radial in the periphery, a vortex in the core. After the onset of these avalanches, the epithelial area grows discontinuously. The avalanches are found to be stochastic, and their strength is correlated with the density of cells in the tissue. Overall, avalanches redistribute accumulated local spatial pressure along the tissue. Furthermore, the distribution of avalanche magnitudes is found to obey a power law, with an exponent consistent with sheer induced avalanches in amorphous materials. To understand the role of avalanches in organ development, we simulate epithelial growth of the Drosophila eye disc during the third instar using a computational model, which includes both chemical and mechanistic signaling. During the third instar, the morphogenetic furrow (MF), a ~10 cell wide wave of apical area constriction propagates through the epithelium. These simulations are used to understand the details of the growth process, the effect of the MF on the growth dynamics on the tissue scale, and to make predictions for experimental observations. The avalanches are found to depend on the strength of the apical constriction of cells in the MF, with a stronger apical constriction leading to less frequent and more pronounced avalanches. The results herein highlight the dependence of simulated tissue growth dynamics on relaxation timescales, and serve as a guide for in vitro experiments.

Formation, collective motion, and merging of macroscopic bacterial aggregates.

Chemotactic bacteria form emergent spatial patterns of variable cell density within cultures that are initially spatially uniform. These patterns are the result of chemical gradients that are created from the directed movement and metabolic activity of billions of cells. A recent study on pattern formation in wild bacterial isolates has revealed unique collective behaviors of the bacteria Enterobacter cloacae. As in other bacterial species, Enterobacter cloacae form macroscopic aggregates. Once formed, these bacterial clusters can migrate several millimeters, sometimes resulting in the merging of two or more clusters. To better understand these phenomena, we examine the formation and dynamics of thousands of bacterial clusters that form within a 22 cm square culture dish filled with soft agar over two days. At the macroscale, the aggregates display spatial order at short length scales, and the migration of cell clusters is superdiffusive, with a merging acceleration that is correlated with aggregate size. At the microscale, aggregates are composed of immotile cells surrounded by low density regions of motile cells. The collective movement of the aggregates is the result of an asymmetric flux of bacteria at the boundary. An agent-based model is developed to examine how these phenomena are the result of both chemotactic movement and a change in motility at high cell density. These results identify and characterize a new mechanism for collective bacterial motility driven by a transient, density-dependent change in motility.

High prevalence of gastrointestinal symptoms in patients with primary Sjögren's syndrome cannot be attributed to pancreatic exocrine insufficiency.

INTRODUCTION: Pancreatic exocrine insufficiency (PEI) results in maldigestion of fat, leading to steatorrhea, malabsorption and weight loss. Sjögren's syndrome (SS) is a chronic autoimmune rheumatic disease with unknown etiology. The exocrine pancreas and the salivary glands are functionally and histologically comparable, and pancreatic dysfunction in SS has been hypothesized. METHODS: Patients were recruited from the Department for Rheumatology at the Karolinska University Hospital in Stockholm, Sweden, between June and December 2019. PEI was assessed by fecal elastase-1 (FE-1) and 13C-mixed triglyceride breath test (13C-MTG-BT). The presence and severity of gastrointestinal symptoms were assessed by a well-established and validated survey based on a seven-point Likert scale. RESULTS: Fifty-seven patients with primary SS were included in the study, comprising 92% females with a median age of 63 years. In total, 87% of SS patients were tested for FE-1 and all had normal results. All patients who underwent a 13C-MTG-BT had a normal cumulative 13C-exhalation. Compared to the control group, significantly more patients suffered from gastrointestinal (GI) symptoms (p < .01). The same number of patients noted moderate to severe loose bowel movements or constipation (38%). Eleven GI symptom parameters were compared to controls and the highest odd ratios were noted for the following moderate to severe symptoms: bloating, feeling of incompletely emptied bowel after defecation and abdominal pain relieved by bowel action. CONCLUSION: In our study, most SS patients suffered from irritable bowel syndrome (IBS)-like GI symptoms that could not be attributed to PEI.

Patient reported exposure to smoking and alcohol abuse are associated with pain and other complications in patients with chronic pancreatitis.

BACKGROUND/OBJECTIVES: Smoking and alcohol abuse are established risk factors for chronic pancreatitis (CP). Few studies have examined how exposure to smoking and alcohol abuse act as risk factors for complications in CP. Our aim was to examine associations between patient reported exposure to smoking and alcohol abuse and complications in CP in a large cohort of patients from the Scandinavian and Baltic countries. METHODS: We retrieved data on demographics, CP related complications and patients' histories of exposure to smoking and alcohol abuse from the Scandinavian Baltic Pancreatic Club database. Associations were investigated by univariate and multivariate logistic regression analyses. Results are presented as odds ratios (OR) with 95% confidence intervals. RESULTS: A complete history of smoking and alcohol exposure was available for 932 patients. In multivariate regression analyses, the presence of pain and exocrine pancreatic insufficiency were both significantly associated with history of smoking (OR 1.94 (1.40-2.68), p < 0.001 and OR 1.89 (1.36-2.62), p < 0.001, respectively) and alcohol abuse (OR 1.66 (1.21-2.26), p = 0.001 and 1.55 (1.14-2.11), p = 0.005, respectively). Smoking was associated with calcifications (OR 2.89 (2.09-3.96), p < 0.001), moderate to severe ductal changes (OR 1.42 (1.05-1.92), p = 0.02), and underweight (OR 4.73 (2.23-10.02), p < 0.001). History of alcohol abuse was associated with pseudocysts (OR 1.38 (1.00-1.90) p = 0.05) and diabetes mellitus (OR 1.44 (1.03-2.01), p = 0.03). There were significantly increased odds-ratios for several complications with increasing exposure to smoking and alcohol abuse. CONCLUSION: Smoking and alcohol abuse are both independently associated with development of complications in patients with CP. There seems to be a dose-dependent relationship between smoking and alcohol abuse and complications in CP.

Association of multiple patient and disease characteristics with the presence and type of pain in chronic pancreatitis.

BACKGROUND AND AIM: Pain is the primary symptom of chronic pancreatitis (CP) and associates with a number of patient and disease characteristics. However, the complex interrelations of these parameters are incompletely understood, and pain treatment remains unsatisfactory in a large proportion of patients. The aim of this study is to investigate multiple pain risk factors in a large population of CP patients, with a special emphasis on patients' patterns of smoking and alcohol use. METHODS: This was a multicenter, cross-sectional study including 1384 patients with CP. Patient demographics and disease characteristics, as well as current patterns of smoking and alcohol use, were compared for patients with pain (n = 801) versus without pain (n = 583). Multivariate logistic regression models were performed to assess the variables associated with the presence and type of pain (constant vs intermittent pain). RESULTS: The mean age of participants was 52.1 ± 14.6 years, and 914 (66%) were men. Active smoking (odds ratio 1.6 [95% confidence interval 1.1-2.2], P = 0.005) and alcohol consumption (odds ratio 1.8 [95% confidence interval 1.1-3.0], P = 0.03) were independently associated with the presence of pain. In addition, patients' age at diagnosis, pancreatic duct pathology, and the presence of pseudocysts, duodenal stenosis, and exocrine pancreatic insufficiency were confirmed as pain risk factors (all P ≤ 0.01). Constant pain, as opposed to intermittent pain, was more frequently reported by smokers (P = 0.03), while alcohol consumption was associated with intermittent pain (P = 0.006). CONCLUSION: Multiple patient and disease characteristics, including patterns of smoking and alcohol consumption, associate with the presence and type of pain in patients with CP.

Chronic Pancreatitis Is Characterized by Distinct Complication Clusters That Associate With Etiological Risk Factors.

OBJECTIVES: Chronic pancreatitis (CP) is characterized by several disease-related complications and multiple etiological risk factors. Past studies of associations between complications and risk factors have mostly been limited to single complications or highly focused on single etiologies. Using an objective data-driven approach (cluster analysis), we characterized complication clusters and their associations with etiological risk factors in a large cohort of patients with CP. METHODS: This was a multicenter, cross-sectional study including 1,071 patients with CP from the Scandinavian and Baltic countries. Complications to CP were classified according to the M-ANNHEIM system, and treelet transform was used to derive complication clusters. Cluster complication frequencies were analyzed for their association with main etiological risk factors (smoking and alcohol). RESULTS: The mean age of participants was 57 years and 66% were men. Alcohol (55%) and smoking (53%) were the most common etiological risk factors and seen in combination in 36% of patients. Cluster analysis identified 3 distinct complication clusters characterized by inflammation, fibrosis, and pancreatic insufficiencies. An independent association between inflammatory complications and alcoholic etiology was seen (odds ratio [OR] 2.00 [95% CI [confidence interval], 1.38-2.90], P < 0.001), whereas smoking was associated with fibrosis-related complications (OR 2.23 [95% CI, 1.56-2.3.20], P < 0.001) and pancreatic insufficiencies (OR 1.42 [95% CI, 1.00-2.01], P = 0.046). DISCUSSION: Three distinctive clusters of complications to CP were identified. Their differing associations with alcoholic and smoking etiology indicate distinct underlying disease mechanisms.

Pancreatic calcifications associate with diverse aetiological risk factors in patients with chronic pancreatitis: A multicentre study of 1500 cases.

BACKGROUND: Pancreatic calcifications is a common finding in patients with chronic pancreatitis (CP), but the underlying pathophysiology is incompletely understood. Past studies for risk factors of calcifications have generally been focused on single parameters or limited by small sample sizes. The aim of this study was to explore several patient and disease characteristics and their associations with pancreatic calcifications in a large cohort of CP patients with diverse aetiological risk factors. METHODS: This was a multicentre, cross-sectional study including 1509 patients with CP. Patient and disease characteristics were compared for patients with calcifications (n = 912) vs. without calcifications (n = 597). Multivariable logistic regression was performed to assess the parameters independently associated with calcifications. RESULTS: The mean age of patients was 53.9 ±â€¯14.5 years and 1006 (67%) were men. The prevalence of calcifications was 60.4% in the overall patient cohort, but highly variable between patients with different aetiological risk factors (range: 2-69%). On multivariate analysis, alcoholic aetiology (OR 1.76 [95% CI, 1.39-2.24]; p < 0.001) and smoking aetiology (OR 1.77 [95% CI, 1.39-2.26], p < 0.001) were positively associated with the presence of calcifications, while an autoimmune aetiology was negatively associated with calcifications (OR 0.15 [95% CI, 0.08-0.27], p < 0.001). Patients with pancreatic calcifications were more likely to have undergone pancreatic duct stenting (OR 1.59 [95%CI, 1.16-2.19], p = 0.004). CONCLUSION: The presence of pancreatic calcifications is associated with diverse aetiological risk factors in patients with CP. This observation attest to the understanding of CP as a complex disease and may have implications for disease classification.

Diagnostic performance of a stepwise cytological algorithm for biliary malignancy in primary sclerosing cholangitis.

BACKGROUND AND AIMS: Detection of early cholangiocarcinoma (CCA) in primary sclerosing cholangitis (PSC) is challenging. The aim of this study was to evaluate the diagnostic accuracy of a stepwise approach to biliary brush cytology with sequential use of fluorescence in-situ hybridization (FISH) for the detection of biliary malignancy in PSC. METHOD: We retrospectively studied consecutive patients with PSC who underwent biliary brushings at Karolinska University Hospital between 2009 and 2015 (n = 208). Brush samples were categorized as benign, equivocal (atypical or suspicious) and malignant. Equivocal cases were further analysed with FISH. Samples with a malignant cytology or positive FISH were considered positive. The diagnosis was determined after 12 months of follow-up. RESULTS: The diagnosis CCA was confirmed in 15 patients (7%), high-grade dysplasia in three patients, and low-grade dysplasia in five patients at follow-up. Using the diagnostic algorithm, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) for a diagnosis of CCA were 80% (95%CI 52%-96%), 96% (95%CI 92%-98%), 60% (95%CI 36%-81%) and 98% (95% CI 95%-100%). In patients with equivocal cytology (n = 61), the sensitivity for CCA diagnosis increased to 100% (95%CI 72%-100%) with a lower PPV of 58% (95%CI 34%-78%). The diagnostic accuracy for detection of CCA in all patients was 95% (95%CI 91%-97%). CONCLUSION: Biliary brush cytology with sequential use of FISH in equivocal cases seems to be a highly predictive diagnostic test for CCA in PSC. These results support the use of FISH when cytology is equivocal for detection of biliary malignancy in PSC.

RCAN1 is a marker of oxidative stress, induced in acute pancreatitis.

BACKGROUND: To date, there still is a lack of specific acute pancreatitis markers and specifically an early marker that can reliably predict disease severity. The inflammatory response in acute pancreatitis is mediated in part through oxidative stress and calcineurin-NFAT (Nuclear Factor of Activated T-cells) signaling, which is inducing its own negative regulator, regulator of calcineurin 1 (RCAN1). Caerulein induction is a commonly used in vivo model of experimental acute pancreatitis. Caerulein induces CN-NFAT signaling, reactive oxygen species and inflammation. METHODS: To screen for potential markers of acute pancreatitis, we used the caerulein model of experimental acute pancreatitis (AP) in C57Bl/6 J mice. Pancreata from treated and control mice were used for expression profiling. Promising gene candidates were validated in cell culture experiments using primary murine acinar cells and rat AR42J cells. These candidates were then further tested for their usefulness as biomarkers in mouse and human plasma. RESULTS: We identified a number of novel genes, including Regulator of calcineurin 1 (Rcan1) and Sestrin 2 (Sesn2) and demonstrated that they are induced by oxidative stress, by stimulation with H2O2 and by inhibiting caerulein stimulated expression with the antioxidant N-acetylcysteine. We found Rcan1 protein to be significantly elevated in AP-induced mouse plasma as well as in plasma from AP patients. CONCLUSION: We demonstrated that Rcan1 is regulated by oxidative stress and identified RCAN1 as a potential diagnostic marker of AP.

Diagnosis, treatment and long-term outcome of autoimmune pancreatitis in Sweden.

INTRODUCTION: Autoimmune pancreatitis (AIP) is a pancreatic inflammatory process characterized by a strong inflammatory cell infiltration and two histopathologically distinct subtypes: type 1 and type 2. Diagnosis is often challenging and requires a combination of clinical, laboratory and imaging data. AIP can mimic pancreatic tumours leading to unnecessary resections if not correctly diagnosed. Short- and long-term outcomes of AIP have been poorly investigated so far and no large series have been previously reported from Sweden. METHODS: A single-centre, retrospective, cohort study of patients with histologically confirmed or highly probable diagnosis of AIP according to ICDC criteria. Demographic, clinical and radiological characteristics, type of treatment and its outcomes were collected and analysed. RESULTS: Seventy-one patients with AIP (87% with type 1), were evaluated at Karolinska University Hospital between 2004 and 2018; 49% males, mean age 49 years (range 44-53). Among them, 28% were histologically confirmed, 35% presented with jaundice, 22% with acute pancreatitis, 39% had non-specific symptoms such as weight loss or abdominal pain, 84% showed other organ involvement (OOI). Radiologically, 76% showed a focal pancreatic enlargement, 27% diffuse enlargement, 27% signs of acute pancreatitis and 10% of chronic pancreatitis. Overall, 58 patients (81%) underwent treatment with different medications: 46 (79%) cortisone, 7 (12%) azathioprine, 5 (8%) other immunosuppressive drugs. Twenty-six (36%) underwent biliary stenting and 12 (16%) were given surgery. In total, 47% of patients developed pancreatic exocrine insufficiency (PEI), of whom 76% had a severe form (faecal elastase-1 < 100 µg/g) and 21% of patients developed diabetes mellitus (pancreatic endocrine insufficiency), of whom 73% required insulin. CONCLUSIONS: AIP is a challenging disease for diagnosis and treatment. Cortisone treatment is generally successful and provides clinical remission in the large majority of patients (>90%). In the further course of the disease, a considerable number of patients develop PEI and diabetes. Only one-quarter of patients exhibit on imaging the characteristic "sausage-like" pancreas (diffuse enlargement), approximately three-quarters had a focal mass that could be misdiagnosed as pancreatic malignancy.

Bose glass and Mott glass of quasiparticles in a doped quantum magnet.

The low-temperature states of bosonic fluids exhibit fundamental quantum effects at the macroscopic scale: the best-known examples are Bose-Einstein condensation and superfluidity, which have been tested experimentally in a variety of different systems. When bosons interact, disorder can destroy condensation, leading to a 'Bose glass'. This phase has been very elusive in experiments owing to the absence of any broken symmetry and to the simultaneous absence of a finite energy gap in the spectrum. Here we report the observation of a Bose glass of field-induced magnetic quasiparticles in a doped quantum magnet (bromine-doped dichloro-tetrakis-thiourea-nickel, DTN). The physics of DTN in a magnetic field is equivalent to that of a lattice gas of bosons in the grand canonical ensemble; bromine doping introduces disorder into the hopping and interaction strength of the bosons, leading to their localization into a Bose glass down to zero field, where it becomes an incompressible Mott glass. The transition from the Bose glass (corresponding to a gapless spin liquid) to the Bose-Einstein condensate (corresponding to a magnetically ordered phase) is marked by a universal exponent that governs the scaling of the critical temperature with the applied field, in excellent agreement with theoretical predictions. Our study represents a quantitative experimental account of the universal features of disordered bosons in the grand canonical ensemble.

Diagnosing autoimmune pancreatitis with the Unifying-Autoimmune-Pancreatitis-Criteria.

BACKGROUND/OBJECTIVES: We had developed the Unifying-Autoimmune-Pancreatitis-Criteria (U-AIP) to diagnose autoimmune pancreatitis (AiP) within the M-ANNHEIM classification of chronic pancreatitis. In 2011, International-Consensus-Diagnostic-Criteria (ICDC) to diagnose AiP have been published. We had applied the U-AIP long before the ICDC were available. The aims of the study were, first, to describe patients with AiP diagnosed by the U-AIP; second, to compare diagnostic accuracies of the U-AIP and other diagnostic systems; third, to evaluate the clinical applicability of the U-AIP. METHODS: From 1998 until 2008, we identified patients with AiP using U-AIP, Japanese-, Korean-, Asian-, Mayo-HISORt-, Revised-Mayo-HISORt- and Italian-criteria. We retrospectively verified the diagnosis by ICDC and Revised-Japanese-2011-criteria, compared diagnostic accuracies of all systems and evaluated all criteria in consecutive patients with pancreatitis (2009 until 2010, Pancreas-Outpatient-Clinic-Cohort, n = 84). We retrospectively validated our diagnostic approach in consecutive patients with a pancreatic lesion requiring surgery (Surgical-Cohort, n = 98). RESULTS: Overall, we identified 21 patients with AiP. Unifying-Autoimmune-Pancreatitis-Criteria and ICDC presented the highest diagnostic accuracies (each 98.8%), highest Youden indices (each 0.95238), and highest proportions of diagnosed patients (each n = 20/21, U-AIP/ICDC vs. other diagnostic systems, p < 0.05, McNemar test). In the Pancreas-Outpatient-Clinic-Cohort, seven patients were diagnosed with AiP (n = 6 by U-AIP, n = 1 by Asian-criteria). International-Consensus-Diagnostic-Criteria confirmed the diagnosis in these individuals. Based on partial fulfillment of U-AIP, AiP was initially suspected in 13% (n = 10/77) of remaining patients from the Pancreas-Outpatient-Clinic-Cohort. In the Surgical-cohort, we identified one patient with AiP by U-AIP and ICDC. CONCLUSIONS: Unifying-Autoimmune-Pancreatitis-Criteria revealed a satisfactory clinical applicability and offered an additional approach to diagnose AiP.

K+ Block Is the Mechanism of Functional Asymmetry in Bacterial Na(v) Channels.

Crystal structures of several bacterial Na(v) channels have been recently published and molecular dynamics simulations of ion permeation through these channels are consistent with many electrophysiological properties of eukaryotic channels. Bacterial Na(v) channels have been characterized as functionally asymmetric, and the mechanism of this asymmetry has not been clearly understood. To address this question, we combined non-equilibrium simulation data with two-dimensional equilibrium unperturbed landscapes generated by umbrella sampling and Weighted Histogram Analysis Methods for multiple ions traversing the selectivity filter of bacterial Na(v)Ab channel. This approach provided new insight into the mechanism of selective ion permeation in bacterial Na(v) channels. The non-equilibrium simulations indicate that two or three extracellular K+ ions can block the entrance to the selectivity filter of Na(v)Ab in the presence of applied forces in the inward direction, but not in the outward direction. The block state occurs in an unstable local minimum of the equilibrium unperturbed free-energy landscape of two K+ ions that can be 'locked' in place by modest applied forces. In contrast to K+, three Na+ ions move favorably through the selectivity filter together as a unit in a loose "knock-on" mechanism of permeation in both inward and outward directions, and there is no similar local minimum in the two-dimensional free-energy landscape of two Na+ ions for a block state. The useful work predicted by the non-equilibrium simulations that is required to break the K+ block is equivalent to large applied potentials experimentally measured for two bacterial Na(v) channels to induce inward currents of K+ ions. These results illustrate how inclusion of non-equilibrium factors in the simulations can provide detailed information about mechanisms of ion selectivity that is missing from mechanisms derived from either crystal structures or equilibrium unperturbed free-energy landscapes.

The Scandinavian baltic pancreatic club (SBPC) database: design, rationale and characterisation of the study cohort.

OBJECTIVES: Chronic pancreatitis (CP) is a multifaceted disease associated with several risk factors and a complex clinical presentation. We established the Scandinavian Baltic Pancreatic Club (SBPC) Database to characterise and study the natural history of CP in a Northern European cohort. Here, we describe the design of the database and characteristics of the study cohort. METHODS: Nine centres from six different countries in the Scandinavian-Baltic region joined the database. Patients with definitive or probable CP (M-ANNHEIM diagnostic criteria) were included. Standardised case report forms were used to collect several assessment variables including disease aetiology, duration of CP, preceding acute pancreatitis, as well as symptoms, complications, and treatments. The clinical stage of CP was characterised according to M-ANNNHEIM. Yearly follow-up is planned for all patients. RESULTS: The study cohort comprised of 910 patients (608 men: 302 women; median age 58 (IQR: 48-67) years with definite 848 (93%) or probable CP 62 (7%). Nicotine (70%) and alcohol (59%) were the most frequent aetiologies and seen in combination in 44% of patients. A history of recurrent acute pancreatitis was seen in 49% prior to the development of CP. Pain (69%) and exocrine pancreatic insufficiency (68%) were the most common complications followed by diabetes (43%). Most patients (30%) were classified as clinical stage II (symptomatic CP with exocrine or endocrine insufficiency). Less than 10% of the patients had undergone pancreatic surgery. CONCLUSION: The SBPC database provides a mean for future prospective, observational studies of CP in the Northern European continent.

Altered bone metabolism and bone density in patients with chronic pancreatitis and pancreatic exocrine insufficiency.

CONTEXT: Due to maldigestion, pancreatic exocrine insufficiency (PEI) in chronic pancreatitis may lead to deficiencies in fat-soluble vitamins, including vitamin D. This may, in turn, can cause disturbances in bone metabolism and reduce bone mineral density. OBJECTIVE: To conduct a prospective study of maldigestion, bone metabolism, and bone mineral density in a group of patients with chronic pancreatitis. METHODS: A total of 50 male patients with proven chronic pancreatitis (36/50 alcohol; 42/50 smokers) were studied. Pancreatic exocrine function was assessed using the fecal elastase-1 test. Blood and urine samples were analyzed for parameters related to pancreatitis, nutrition, endocrine status, and bone metabolism. Bone mineral density was measured with dual-energy X-ray absorption (DXA) and conventional vertebral X-rays. A standardized questionnaire for osteoporosis was given. RESULTS: Twenty-eight of the patients had PEI (fecal elastase-1 <200 µg/g), 25 had bone pain, and 21 had a history of bone fractures. Serum 25-OH-cholecalciferol and urine calcium were decreased and deoxypyridinoline concentrations were increased in urine. Serum calcium, bone-specific alkaline phosphatase, and parathyroid hormone were within normal limits. There was no statistical correlation between three classes of fecal elastase-1 (<100 µg/g; 100-200 µg/g; >200 µg/g) and calcium, 25-OH-cholecalciferol, or deoxypyridinoline. Of the 15 patients who underwent DXA, 5 had normal bone mineral density (T score >-1), 9 had osteopenia (T score from -1 to - 2.5), and 1 had osteoporosis (T score <-2.5). There was a trend toward a correlation between low fecal elastase-1 and low T scores (P=0.065). Low fecal elastase-1 correlated with low bone mineral density in conventional X-rays (P<0.05). Patients receiving pancreatic enzyme replacement therapy (PERT) had significantly higher DXA values (P<0.05). CONCLUSIONS: Patients with chronic pancreatitis have osteoporosis, along with abnormal bone metabolism and reduced bone mineral density as measured by DXA and X-ray. PERT is associated with less osteopathy.

Crossover physics in the nonequilibrium dynamics of quenched quantum impurity systems.

A general framework is proposed to tackle analytically local quantum quenches in integrable impurity systems, combining a mapping onto a boundary problem with the form factor approach to boundary-condition-changing operators introduced by Lesage and Saleur [Phys. Rev. Lett. 80, 4370 (1998)]. We discuss how to compute exactly the following two central quantities of interest: the Loschmidt echo and the distribution of the work done during the quantum quench. Our results display an interesting crossover physics characterized by the energy scale T(b) of the impurity corresponding to the Kondo temperature. We discuss in detail the noninteracting case as a paradigm and benchmark for more complicated integrable impurity models and check our results using numerical methods.

Rapid progression of a splenic aneurysm due to segmental arterial mediolysis: a rare cause of acute pancreatitis.

BACKGROUND: The etiology of acute pancreatitis can be manifold, beside the usual causes. We are reporting an unusual cause that triggered acute pancreatitis. PATIENT & RESULTS: A 50 year-old male experienced attacks of acute pancreatitis (abdominal pain and elevated amylase and lipase) during sexual arousal. Serial imaging showed a rapidly-progressing, partly-thrombosed splenic artery aneurysm, with local compression of the pancreas. After angiographic coiling, the attacks subsided. Further angiography revealed additional aneurysms consistent with segmental arterial mediolysis at other sites of the body. Molecular analysis regarding Ehlers-Danlos-syndrome and genetic factors for pancreatitis, autoantibodies and Syphilis serology was negative. CONCLUSIONS: Acute pancreatitis was triggered by a transient rise in blood pressure during sexual stimulation, which caused rapid progression of a splenic artery aneurysm as part of systemic segmental arterial mediolysis.

Dissecting the genetic heterogeneity of gastric cancer.

BACKGROUND: Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture. METHODS: We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO. FINDINGS: Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level. INTERPRETATION: Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO. FUNDING: German Research Foundation (DFG).

Alcohol consumption and digestive tract cancer.

PURPOSE OF REVIEW: The data indicating that alcohol is an important factor increasing the risk to develop gastrointestinal cancer are consolidating. The purpose of this review is to summarize current evidence. RECENT FINDINGS: Acetaldehyde is the first metabolite of ethanol metabolism and has direct carcinogenic and mutagenic effects by modifying DNA via generation of DNA adducts. Oxidative stress has a prominent role in triggering chronic inflammation and carcinogenesis through formation of reactive oxygen species. Recently published large prospective cohort studies with sufficient statistical power and meta-analyses could refine the knowledge regarding the impact of alcohol on gastrointestinal cancer. Functional genetic variants of alcohol-metabolizing enzymes proved to be associated with increased risk for esophageal and gastric cancer.The highest risk increase for malignancy was observed in the upper aerodigestive tract (oral cavity, pharynx, larynx) and esophagus (squamous cell carcinoma), weaker correlations were established regarding gastric, pancreatic, and colorectal neoplasias. SUMMARY: Alcohol overconsumption is a serious avoidable risk factor for the development of gastrointestinal tract cancer, both alone but even more in combination with other risk factors such as tobacco and obesity.

Glucagon and Liver Fat are Downregulated in Response to Very Low-calorie Diet in Patients with Obesity and Type-2 Diabetes.

BACKGROUND AND STUDY AIMS: In patients with obesity and type-2 diabetes, short-time very low-calorie diet may ameliorate hyperglycemia and hepatic steatosis. Whether this also implies the glucose-regulating hormone glucagon remains to be elucidated. This study investigated the effects of a very low-calorie diet on plasma levels of glucagon and liver fat in obese patients with type-2 diabetes. PATIENTS AND METHODS: Ten obese patients with type-2 diabetes, 6 men and 4 women, were included. At baseline, fasting plasma glucagon, insulin and glucose were determined, and liver fat and stiffness evaluated by transient elastography. The subjects were then prescribed a very low-calorie diet of maximum 800 kcal/day for 7 weeks and reexamined after 7 weeks and 12 months. RESULTS: At baseline, BMI was 42±4 kg/m2 and fasting glucose 10.6±3.4 mmol/l. All patients had hepatic steatosis. Plasma glucagon was strongly related to liver fat (r2=0.52, p=0.018). After 7 weeks of very low-calorie diet, plasma glucagon was significantly decreased by nearly 30% (p=0.004) along with reductions of BMI (p<0.0001), glucose (p=0.02), insulin (p=0.03), liver fat (p=0.007) and liver stiffness (p=0.05). At 12 months follow-up, both glucagon and liver fat increased and were not different to basal levels, despite persistent reductions of BMI (p<0.002) and glucose (p=0.008). CONCLUSION: In obese type-2 diabetic subjects, plasma glucagon and liver fat are correlated and similarly affected by a very low-calorie diet, supporting a role of hepatic steatosis in glucagon metabolism.