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Dive into the research topics where Johann Ockenga is active.

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Featured researches published by Johann Ockenga.


Nature Genetics | 2008

Chymotrypsin C (CTRC) variants that diminish activity or secretion are associated with chronic pancreatitis.

Jonas Rosendahl; Heiko Witt; Richárd Szmola; Eesh Bhatia; Béla Ózsvári; Olfert Landt; Hans Ulrich Schulz; Thomas M. Gress; Roland H. Pfützer; Matthias Löhr; Peter Kovacs; Matthias Blüher; Michael Stumvoll; Gourdas Choudhuri; Péter Hegyi; Rene H. M. te Morsche; Joost P. H. Drenth; Kaspar Truninger; Milan Macek; Gero Puhl; Ulrike Witt; Hartmut Schmidt; Carsten Büning; Johann Ockenga; Andreas Kage; David A. Groneberg; Renate Nickel; Thomas Berg; Bertram Wiedenmann; Hans Bödeker

Chronic pancreatitis is a persistent inflammatory disease of the pancreas, in which the digestive protease trypsin has a fundamental pathogenetic role. Here we have analyzed the gene encoding the trypsin-degrading enzyme chymotrypsin C (CTRC) in German subjects with idiopathic or hereditary chronic pancreatitis. Two alterations in this gene, p.R254W and p.K247_R254del, were significantly overrepresented in the pancreatitis group, being present in 30 of 901 (3.3%) affected individuals but only 21 of 2,804 (0.7%) controls (odds ratio (OR) = 4.6; confidence interval (CI) = 2.6–8.0; P = 1.3 × 10−7). A replication study identified these two variants in 10 of 348 (2.9%) individuals with alcoholic chronic pancreatitis but only 3 of 432 (0.7%) subjects with alcoholic liver disease (OR = 4.2; CI = 1.2–15.5; P = 0.02). CTRC variants were also found in 10 of 71 (14.1%) Indian subjects with tropical pancreatitis but only 1 of 84 (1.2%) healthy controls (OR = 13.6; CI = 1.7–109.2; P = 0.0028). Functional analysis of the CTRC variants showed impaired activity and/or reduced secretion. The results indicate that loss-of-function alterations in CTRC predispose to pancreatitis by diminishing its protective trypsin-degrading activity.


Clinical Nutrition | 2006

ESPEN Guidelines on Parenteral Nutrition: Pancreas

Luca Gianotti; R Meier; Dileep N. Lobo; Claudio Bassi; Cornelis H.C. Dejong; Johann Ockenga; Øivind Irtun; John MacFie

Assessment of the severity of acute pancreatitis (AP), together with the patients nutritional status is crucial in the decision making process that determines the need for artificial nutrition. Both should be done on admission and at frequent intervals thereafter. The indication for nutritional support in AP is actual or anticipated inadequate oral intake for 5-7 days. This period may be shorter in those with pre-existing malnutrition. Substrate metabolism in severe AP is similar to that in severe sepsis or trauma. Parenteral amino acids, glucose and lipid infusion do not affect pancreatic secretion and function. If lipids are administered, serum triglycerides must be monitored regularly. The use of intravenous lipids as part of parenteral nutrition (PN) is safe and feasible when hypertriglyceridemia is avoided. PN is indicated only in those patients who are unable to tolerate targeted requirements by the enteral route. As rates of EN tolerance increase then volumes of PN should be decreased. When PN is administered, particular attention should be given to avoid overfeeding. When PN is indicated, a parenteral glutamine supplementation should be considered. In chronic pancreatitis PN may, on rare occasions, be indicated in patients with gastric outlet obstruction secondary to duodenal stenosis or those with complex fistulation, and in occasional malnourished patients prior to surgery.


Journal of Hepatology | 1997

Hepatitis B and C in HIV-infected patients: Prevalence and prognostic value

Johann Ockenga; Hans L. Tillmann; Christian Trautwein; Matthias Stoll; Michael P. Manns; Reinhold E. Schmidt

BACKGROUND/AIMS There is only limited information on the prevalence and influence of coinfection with either hepatitis B or C on the clinical course in patients infected with the human immunodeficiency virus (HIV). METHODS Follow-up was available in 232 HIV-infected patients (age 37+/-8 years, CD4 count 167+/-167 microl; 46% had AIDS). Samples were investigated for markers of HBV and HCV infection (HBsAg, HBeAg, HBV-DNA, Anti-HBs, anti-HBc, anti-HCV, HCV-RNA). RESULTS 60/232 patients (23%) were anti-HCV positive. 78% of these sera were positive for HCV-RNA. 22/232 patients (9%) suffered from chronic HBV infection (HBsAg positive), 18/22 (82%) of these sera had detectable HBeAg and 19/22 (86%) HBV-DNA. Presence of HCV-RNA, HBeAg and amount of HBV-DNA were related to the degree of immunodeficiency. In contrast to the control group without HBV or HCV infection, patients infected with HIV and either HBV or HCV showed a direct correlation between a reduction in CD4 counts and decreased cholinesterase activity. In patients with AIDS, coinfection with HBV or HCV was associated with a reduced survival compared to controls (HBV: 212 days, 95%CI, 106-317; HCV: 267, 95%CI, 112-396; controls: 439 days, 95%CI, 364-513). CONCLUSIONS Coinfection of HIV and HBV or HCV is frequently observed. Our results suggest that with prolonged survival of HIV-infected patients, coinfection with either HBV or HCV correlates with a reduced survival rate.


Hepatology | 2013

Extracorporeal albumin dialysis with the molecular adsorbent recirculating system in acute‐on‐chronic liver failure: The RELIEF trial

Rafael Bañares; Frederik Nevens; Fin Stolze Larsen; Rajiv Jalan; Agustín Albillos; Matthias Dollinger; Faouzi Saliba; Tilman Sauerbruch; Sebastian Klammt; Johann Ockenga; Albert Parés; Julia Wendon; Tanja Brünnler; Ludwig Kramer; Philippe Mathurin; Manuel de la Mata; Antonio Gasbarrini; Beat Müllhaupt; Alexander Wilmer; Wim Laleman; Martin Eefsen; Sambit Sen; Alexander Zipprich; Teresa Tenorio; Marco Pavesi; Hartmut Schmidt; Steffen Mitzner; Roger Williams; Vicente Arroyo

Acute‐on‐chronic liver failure (ACLF) is a frequent cause of death in cirrhosis. Albumin dialysis with the molecular adsorbent recirculating system (MARS) decreases retained substances and improves hemodynamics and hepatic encephalopathy (HE). However, its survival impact is unknown. In all, 189 patients with ACLF were randomized either to MARS (n = 95) or to standard therapy (SMT) (n = 94). Ten patients (five per group) were excluded due to protocol violations. In addition, 23 patients (MARS: 19; SMT: 4) were excluded from per‐protocol (PP) analysis (PP population n = 156). Up to 10 6‐8‐hour MARS sessions were scheduled. The main endpoint was 28‐day ITT and PP survival. There were no significant differences at inclusion, although the proportion of patients with Model for Endstage Liver Disease (MELD) score over 20 points and with spontaneous bacterial peritonitis (SBP) as a precipitating event was almost significantly greater in the MARS group. The 28‐day survival was similar in the two groups in the ITT and PP populations (60.7% versus 58.9%; 60% versus 59.2% respectively). After adjusting for confounders, a significant beneficial effect of MARS on survival was not observed (odds ratio [OR]: 0.87, 95% confidence interval [CI] 0.44‐1.72). MELD score and HE at admission and the increase in serum bilirubin at day 4 were independent predictors of death. At day 4, a greater decrease in serum creatinine (P = 0.02) and bilirubin (P = 0.001) and a more frequent improvement in HE (from grade II‐IV to grade 0‐I; 62.5% versus 38.2%; P = 0.07) was observed in the MARS group. Severe adverse events were similar. Conclusion: At scheduled doses, a beneficial effect on survival of MARS therapy in patients with ACLF could not be demonstrated. However, MARS has an acceptable safety profile, has significant dialysis effect, and nonsignificantly improves severe HE. (HEPATOLOGY 2013)


Nature Genetics | 2006

A degradation-sensitive anionic trypsinogen (PRSS2) variant protects against chronic pancreatitis

Heiko Witt; Miklós Sahin-Tóth; Olfert Landt; Jian-Min Chen; Thilo Kähne; Joost P. H. Drenth; Zoltán Kukor; Edit Szepessy; Walter Halangk; Stefan Dahm; Klaus Rohde; Hans Ulrich Schulz; Cédric Le Maréchal; Nejat Akar; Rudolf W. Ammann; Kaspar Truninger; Mario Bargetzi; Eesh Bhatia; Carlo Castellani; Giulia Martina Cavestro; Milos Cerny; Giovanni Destro-Bisol; Gabriella Spedini; Jan B.M.J. Jansen; Monika Koudova; Eva Rausova; Milan Macek; Núria Malats; Francisco X. Real; Hans Jürgen Menzel

Chronic pancreatitis is a common inflammatory disease of the pancreas. Mutations in the genes encoding cationic trypsinogen (PRSS1) and the pancreatic secretory trypsin inhibitor (SPINK1) are associated with chronic pancreatitis. Because increased proteolytic activity owing to mutated PRSS1 enhances the risk for chronic pancreatitis, mutations in the gene encoding anionic trypsinogen (PRSS2) may also predispose to disease. Here we analyzed PRSS2 in individuals with chronic pancreatitis and controls and found, to our surprise, that a variant of codon 191 (G191R) is overrepresented in control subjects: G191R was present in 220/6,459 (3.4%) controls but in only 32/2,466 (1.3%) affected individuals (odds ratio 0.37; P = 1.1 × 10−8). Upon activation by enterokinase or trypsin, purified recombinant G191R protein showed a complete loss of trypsin activity owing to the introduction of a new tryptic cleavage site that renders the enzyme hypersensitive to autocatalytic proteolysis. In conclusion, the G191R variant of PRSS2 mitigates intrapancreatic trypsin activity and thereby protects against chronic pancreatitis.


The Journal of Infectious Diseases | 1998

GB Virus C/Hepatitis G Virus Infection: A Favorable Prognostic Factor in Human Immunodeficiency Virus-Infected Patients?

Stefan Heringlake; Johann Ockenga; Hans L. Tillmann; Christian Trautwein; Dörte Meissner; Matthias Stoll; Jeffrey C. Hunt; Cynthia Jou; Natalie Solomon; Reinhold E. Schmidt; Michael P. Manns

To investigate a possible influence of GB virus C (GBV-C) in immunocompromised patients, the prevalences of GBV-C RNA and anti-E2 antibody in 197 human immunodeficiency virus (HIV)-infected patients and in 120 control blood donors were studied. GBV-C RNA was detected in 33 of 197 HIV-infected patients (16.8%) compared with 1 in 120 blood donors (0.8%) (P < .001). Previous exposure to GBV-C (anti-E2 antibody-positive) was shown in 56.8% of HIV patients and in 9% of blood donors. GBV-C viremia was not associated with hepatitis. Despite approximately equal duration of HIV infection in all subgroups, the CD4 cell counts were significantly higher in GBV-C-viremic patients (344 cells/microL) compared with exposed (259 cells/microL) and unexposed (170 cells/microL) patients (P = .017 and P < .001). Furthermore, Kaplan-Meier analysis demonstrated significantly better cumulative survival in GBV-C RNA-positive HIV-infected patients, suggesting that GBV-C might be a favorable prognostic factor in HIV disease.


Nutrition | 2008

Malnutrition and impaired muscle strength in patients with Crohn's disease and ulcerative colitis in remission

Luzia Valentini; Carsten Büning; Susanne Hengstermann; Thomas Koernicke; Wolfgang Tillinger; Francesco William Guglielmi; Kristina Norman; Sabine Buhner; Johann Ockenga; Matthias Pirlich; Herbert Lochs

OBJECTIVE This prospective, controlled, and multicentric study evaluated nutritional status, body composition, muscle strength, and quality of life in patients with inflammatory bowel disease in clinical remission. In addition, possible effects of gender, malnutrition, inflammation, and previous prednisolone therapy were investigated. METHODS Nutritional status (subjective global assessment [SGA], body mass index, albumin, trace elements), body composition (bioelectrical impedance analysis, anthropometry), handgrip strength, and quality of life were assessed in 94 patients with Crohns disease (CD; 61 female and 33 male, Crohns Disease Activity Index 71 +/- 47), 50 patients with ulcerative colitis (UC; 33 female and 17 male, Ulcerative Colitis Activity Index 3.1 +/- 1.5), and 61 healthy control subjects (41 female and 20 male) from centers in Berlin, Vienna, and Bari. For further analysis of body composition, 47 well-nourished patients with inflammatory bowel disease were pair-matched by body mass index, sex, and age to healthy controls. Data are presented as median (25th-75th percentile). RESULTS Most patients with inflammatory bowel disease (74%) were well nourished according to the SGA, body mass index, and serum albumin. However, body composition analysis demonstrated a decrease in body cell mass (BCM) in patients with CD (23.1 kg, 20.8-28.7, P = 0.021) and UC (22.6 kg, 21.0-28.0, P = 0.041) compared with controls (25.0 kg, 22.0-32.5). Handgrip strength correlated with BCM (r = 0.703, P = 0.001) and was decreased in patients with CD (32.8 kg, 26.0-41.1, P = 0.005) and UC (31.0 kg, 27.3-37.8, P = 0.001) compared with controls (36.0 kg, 31.0-52.0). The alterations were seen even in patients classified as well nourished. BCM was lower in patients with moderately increased serum C-reactive protein levels compared with patients with normal levels. CONCLUSION In CD and UC, selected micronutrient deficits and loss of BCM and muscle strength are frequent in remission and cannot be detected by standard malnutrition screening.


Journal of Clinical Investigation | 2002

Impaired glucose phosphorylation and transport in skeletal muscle cause insulin resistance in HIV-1–infected patients with lipodystrophy

Georg M. N. Behrens; Anne-Rose Boerner; Klaus Weber; Joerg van den Hoff; Johann Ockenga; Georg Brabant; Reinhold Schmidt

Insulin resistance is a frequently observed side effect of highly active antiretroviral therapy (HAART). Currently, very little is known about the mechanisms or specific tissues involved. We aimed to identify possible defects in skeletal muscle glucose uptake and metabolism in HIV patients receiving HAART. Whole-body glucose disposal and oxidation were determined by combination of the euglycemic-hyperinsulinemic clamp technique and indirect calorimetry. Muscle glucose uptake of the thighs was measured simultaneously by dynamic 2[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography. Patients receiving HAART had signs of lipodystrophy as confirmed by dual energy x-ray absorptiometry. Whole-body glucose disposal was significantly reduced in these patients compared with untreated patients. Analysis of kinetic constants using a three-compartment model indicated reduced skeletal glucose uptake caused by significantly impaired glucose transport and phosphorylation. Skeletal muscle glucose uptake was reduced by 66% in treated patients and explained 46% and 43% of whole-body glucose disposal in patients on HAART and therapy-naive patients, respectively. Insulin-stimulated whole-body oxidative and nonoxidative glucose disposal was significantly lower in the treated group, as was suppressive insulin action on lipolysis. To our knowledge, this is the first report providing in vivo evidence that, in lipodystrophic HIV patients, impaired glucose transport and phosphorylation cause reduced insulin-mediated glucose uptake.


Nutrition | 2009

Circulating adipokines and the protective effects of hyperinsulinemia in inflammatory bowel disease.

Luzia Valentini; Eva K. Wirth; Ulrich Schweizer; Susanne Hengstermann; Thomas Koernicke; Ekkehart Dietz; Kristina Norman; Carsten Büning; Brigitte M. Winklhofer-Roob; Herbert Lochs; Johann Ockenga

OBJECTIVE Adipokines are fat-derived hormones and cytokines with immune-modulating and metabolic properties. Most of them are associated with insulin resistance. The aim of the present investigation was to evaluate circulating levels of adipokines and glucose homeostasis in patients with inflammatory bowel disease (IBD) and to evaluate possible associations with the course and characteristics of the disease. METHODS Serum leptin, resistin, visfatin, retinol-binding protein-4, adiponectin, glucose, insulin, and inflammatory parameters were analyzed in 93 patients with inactive IBD (49 with Crohns disease [CD], 44 with ulcerative colitis [UC]), 35 patients with active IBD (18 with CD, 17 with UC), and 37 age- and body mass index-matched healthy controls. Ninety-two patients were followed for 6 mo. RESULTS Leptin was similar in patients with IBD and controls, whereas resistin and visfatin were increased in patients with active disease but not in those in remission. In active and inactive disease, adiponectin was decreased (P < 0.001) and retinol-binding protein-4 was increased (P < 0.001) compared with controls. About 60% of patients with IBD showed increased levels of insulin, whereas serum glucose remained normal, resulting in increased homeostasis model assessment values in most patients. Hyperinsulinemia was associated with the decrease in adiponectin (r = -0.572, P < 0.001) and proved to be an independent protective factor for 6-mo maintenance of remission (P = 0.016). CONCLUSION IBD led to largely similar alterations in circulating adipokines and hyperinsulinemia in patients with CD and those with UC. The unexpected protective effect of hyperinsulinemia on relapse rate denotes the role of the metabolic-inflammatory response as a modulator in IBD.


European Journal of Clinical Nutrition | 2005

Glutamine-enriched total parenteral nutrition in patients with inflammatory bowel disease

Johann Ockenga; Kersten Borchert; E. Stüber; Herbert Lochs; Michael P. Manns; Stephan C. Bischoff

Background:Studies in animal models of inflammatory bowel disease (IBD) suggest that supplementation of total parenteral nutrition with glutamine (gln), a conditionally essential amino acid in catabolic conditions, increases gln plasma concentrations, reduces intestinal damage, improves nitrogen balance and may improve the course of the disease. However, human data supporting this assumption are missing.Methods:A total of 24 consecutive patients with an acute exacerbation of IBD (19 Crohns disease; five ulcerative colitis) and scheduled for total parenteral nutrition (TPN) (>7 days) were randomised. Parallel to a standardised anti-inflammatory therapy, the patients received either a TPN with 1.5 g/kg body weight of a standard amino acid or an isonitrogenic, isocaloric TPN with 1.2 g/kg body weight of a standard amino acid and 0.3 g/kg L-alanine-L-glutamine. Primary end points were gln plasma concentrations and intestinal permeability assessed by urinary lactulose and D-xylose ratio.Results:Gln plasma levels did not differ significantly in either group throughout the study. Intestinal permeability did not change within 7 days either with or without gln supplementation (Δ-lactulose/xylose ratio: 0.01±0.05 (gln+) vs 0.02±0.1 (gln−)). The observed changes in inflammatory and nutritional parameters, and also disease activity, length of TPN and hospital stay, were independent of glutamine substitution. Five (41%) patients in the gln+ group and three (25%) patients in the gln− group needed surgical intervention.Conclusion:Although limited by the sample size, these results do not support the hypothesis that glutamine substitution has an obvious biochemical or clinical benefit in patients with active IBD scheduled for total parenteral nutrition.

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