Point-shear wave elastography generated by acoustic radiation force impulse in chronic pancreatitis.

BACKGROUND: Transcutaneous point-shear wave elastography (p-SWE) performed using an acoustic radiation force impulse can be used to quantify pancreatic stiffness in chronic pancreatitis (CP). We aimed to evaluate its usefulness to diagnose and monitor CP. METHODS: 175 participants were included in this prospective study including patients with CP (n = 65), liver cirrhosis (LC; n = 60), alcohol abuse (n = 10) and healthy controls (n = 40). Point-shear wave elastography of the pancreas was performed and quantified as median shear wave velocity (SWV). In the same way, p-SWE of the spleen served as a marker of portal hypertension. The M-ANNHEIM Severity score was used as global marker for disease activity in CP. RESULTS: Compared to healthy controls, pancreatic SWV was significantly elevated in CP (1.38 vs. 0.96 m/s; p < 0.0001, MWU-test). Pancreatic SWV was increased in alcoholic CP but not in hereditary CP. Receiver operating characteristic analysis revealed 1.2 m/s as the optimal cut-off to identify non-heredity-CP subjects (90% specificity; 81% sensitivity; 92% positive predictive value). Pancreatic SWV correlated significantly with the M-ANNHEIM Severity score, severity of CP-typical complications (both p < 0.05, linear regression analysis), morphological changes of the pancreas and need for hospital treatment (both p < 0.05, MWU-test) but not with exocrine or endocrine insufficiency. Pancreatic SWV >1.7 m/s was identified to predict M-ANNHEIM Severity score ≥11 points. Pancreatic SWV was also elevated in LC (1.42 m/s; p < 0.001), correlating with increased splenic SWV. CONCLUSION: Transcutaneous pancreatic p-SWE represents a bedside, cost-effective and non-invasive tool which adds valuable information to the process of diagnosing and monitoring CP. By portal hypertension, an increased pancreatic SWV must be expected.

Impact of alcohol and smoking cessation on the course of chronic pancreatitis.

OBJECTIVES: Alcohol and nicotine are the two most important risk factors of chronic pancreatitis and they often occur together. It is still unclear how much they influence the severity of the disease and which of the two addictions should be treated with priority. METHODS: We performed a single-center, retrospective, cross-sectional study in a mixed medicosurgical cohort of 870 patients diagnosed with chronic pancreatitis (CP). We analyzed the impact of the drinking pattern and abstinence for alcohol and nicotine on the course of the disease. Patients with alcoholic CP were subdivided in I) patients with "life-time drinking history" (LTDH), II) "current drinkers" with current alcohol abuse without signs of LTDH, and III) "former drinkers" who stopped or reduced alcohol intake dramatically. RESULTS: Compared to patients with LTDH, "former drinkers" had a lower rate of exocrine insufficiency (29% vs. 59%) and pseudocysts (33% vs. 49%), were more often relapse-free (37% vs. 5%) and had less abdominal pain. There was no correlation detected between the quantity of alcohol consumption and the severity or progression of the disease. Regarding nicotine, 29 pack years are the threshold for developing early stage of CP. Under nicotine abstinence, only slightly more patients were relapse-free (37% vs. 22%). In contrast, the cumulative amount of nicotine consumed correlated with overall disease severity and the development of pseudocysts. The need for surgery was increased with odds ratios of 1.8 for both, alcohol and nicotine abuse. CONCLUSIONS: Alcohol cessation in chronic pancreatitis reduces exocrine insufficiency, abdominal pain and local complications. The effect of nicotine cessation is less pronounced in our cohort. However, nicotine abuse represents an important factor for the development of the disease.

Impact of etiology on disease course in chronic pancreatitis.

BACKGROUND: Complications in chronic pancreatitis (CP) can be grouped in inflammatory (ICC) and fibrotic (FCC) clusters and pancreatic insufficiency cluster (PIC). However, the association between etiological risk factors and the development of complication clusters remains obscure. In this study, the impact of the etiology and disease duration on disease onset and development of complications was investigated. METHODS: This cross-sectional study recruited patients with CP from Mannheim/Germany (n = 870), Gießen/Germany (n = 100) und Donetsk/Ukraine (n = 104). Etiological risk factors, disease stage, age at disease onset, complications, need for hospitalization and surgery were noted. RESULTS: In 1074 patients diagnosed with CP, main risk factors were alcohol and nicotine abuse. An earlier onset of the disease was observed upon nicotine abuse (-4.0 years). Alcohol abuse was only associated with an earlier onset of the definite stage of CP. Alcohol abuse was the major risk factor for the development of ICC (p < 0.0001, multiple regression modeling). Abstinence of alcohol reduced ICC, whereas abstinence of nicotine showed no association. PIC correlated with efferent duct abnormalities and the disease duration. In contrast, FCC was mainly dependent on the disease duration (p < 0.0001; t-test). The presence of any complication cluster correlated with the need for surgery (p < 0.01; X2-test). However, only ICC correlated with a prolonged hospital stay (p < 0.05; t-test). CONCLUSIONS: ICC is mainly dependent on alcohol abuse. In contrast, FCC and PIC are mainly dependent on the disease duration. The etiology and disease duration can be used as predictors of the course of disease to provide individual treatment and surveillance strategies.

Differences in junction-associated gene expression changes in three rat models of diabetic retinopathy with similar neurovascular phenotype.

Diabetic retinopathy, also defined as microvascular complication of diabetes mellitus, affects the entire neurovascular unit with specific aberrations in every compartment. Neurodegeneration, glial activation and vasoregression are observed consistently in models of diabetic retinopathy. However, the order and the severity of these aberrations varies in different models, which is also true in patients. In this study, we analysed rat models of diabetic retinopathy with similar phenotypes to identify key differences in the pathogenesis. For this, we focussed on intercellular junction-associated gene expression, which are important for the communication and homeostasis within the neurovascular unit. Streptozotocin-injected diabetic Wistar rats, methylglyoxal supplemented Wistar rats and polycystin-2 transgenic (PKD) rats were analysed for neuroretinal function, vasoregression and retinal expression of junction-associated proteins. In all three models, neuroretinal impairment and vasoregression were observed, but gene expression profiling of junction-associated proteins demonstrated nearly no overlap between the three models. However, the differently expressed genes were from the main classes of claudins, connexins and integrins in all models. Changes in Rcor1 expression in diabetic rats and Egr1 expression in PKD rats confirmed the differences in upstream transcription factor level between the models. In PKD rats, a possible role for miRNA regulation was observed, indicated by an upregulation of miR-26b-5p, miR-122-5p and miR-300-3p, which was not observed in the other models. In silico allocation of connexins revealed not only differences in regulated subtypes, but also in affected retinal cell types, as well as connexin specific upstream regulators Sox7 and miR-92a-3p. In this study, we demonstrate that, despite their similar phenotype, models for diabetic retinopathy exhibit significant differences in their pathogenic pathways and primarily affected cell types. These results underline the importance for more sensitive diagnostic tools to identify pathogenic clusters in patients as the next step towards a desperately needed personalized therapy.

Protective Effects of Transient Glucose Exposure in Adult C. elegans.

C. elegans are used to study molecular pathways, linking high glucose levels (HG) to diabetic complications. Persistent exposure of C. elegans to a HG environment induces the mitochondrial formation of reactive oxygen species (ROS) and advanced glycation endproducts (AGEs), leading to neuronal damage and decreased lifespan. Studies suggest that transient high glucose exposure (TGE) exerts different effects than persistent exposure. Thus, the effects of TGE on ROS, AGE-formation and life span were studied in C. elegans. Four-day TGE (400 mM) as compared to controls (0mM) showed a persistent increase of ROS (4-days 286 ± 40 RLUs vs. control 187 ± 23 RLUs) without increased formation of AGEs. TGE increased body motility (1-day 0.14 ± 0.02; 4-days 0.15 ± 0.01; 6-days 0.16 ± 0.02 vs. control 0.10 ± 0.02 in mm/s), and bending angle (1-day 17.7 ± 1.55; 3-days 18.7 ± 1.39; 6-days 20.3 ± 0.61 vs. control 15.3 ± 1.63 in degree/s) as signs of neuronal damage. Lifespan was increased by 27% (21 ± 2.4 days) after one-day TGE, 34% (22 ± 1.2 days) after four-days TGE, and 26% (21 ± 1.4 days) after six-days TGE vs. control (16 ± 1.3 days). These experiments suggest that TGE in C. elegans has positive effects on life span and neuronal function, associated with mildly increased ROS-formation. From the perspective of metabolic memory, hormetic effects outweighed the detrimental effects of a HG environment.

Glucosamine protects against neuronal but not vascular damage in experimental diabetic retinopathy.

OBJECTIVE: Glucosamine, an intermetabolite of the hexosamine biosynthesis pathway (HBP), is a widely used nutritional supplement in osteoarthritis patients, a subset of whom also suffer from diabetes. HBP is activated in diabetic retinopathy (DR). The aim of this study is to investigate the yet unclear effects of glucosamine on DR. METHODS: In this study, we tested the effect of glucosamine on vascular and neuronal pathology in a mouse model of streptozotocin-induced DR in vivo and on cultured endothelial and Müller cells to elucidate the underlying mechanisms of action in vitro. RESULTS: Glucosamine did not alter the blood glucose or HbA1c levels in the animals, but induced body weight gain in the non-diabetic animals. Interestingly, the impaired neuronal function in diabetic animals could be prevented by glucosamine treatment. Correspondingly, the activation of Müller cells was prevented in the retina as well as in cell culture. Conversely, glucosamine administration in the normal retina damaged the retinal vasculature by increasing pericyte loss and acellular capillary formation, likely by interfering with endothelial survival signals as seen in vitro in cultured endothelial cells. Nevertheless, under diabetic conditions, no further increase in the detrimental effects were observed. CONCLUSIONS: In conclusion, the effects of glucosamine supplementation in the retina appear to be a double-edged sword: neuronal protection in the diabetic retina and vascular damage in the normal retina. Thus, glucosamine supplementation in osteoarthritis patients with or without diabetes should be taken with care.