23 results on '"Würger T"'
Search Results
2. Upregulation of osteoprotegerin expression correlates with bone invasion and predicts poor clinical outcome in oral cancer
- Author
-
Russmueller, G., Moser, D., Würger, T., Wrba, F., Christopoulos, P., Kostakis, G., Seemann, R., Stadler, V., Wimmer, G., Kornek, G., Psyrri, A., Filipits, M., and Perisanidis, C.
- Published
- 2015
- Full Text
- View/download PDF
3. Osteoclasts on Bone and Dentin In Vitro: Mechanism of Trail Formation and Comparison of Resorption Behavior
- Author
-
Rumpler, M., Würger, T., Roschger, P., Zwettler, E., Sturmlechner, I., Altmann, P., Fratzl, P., Rogers, M. J., and Klaushofer, K.
- Published
- 2013
- Full Text
- View/download PDF
4. ATR-FTIR in Kretschmann configuration integrated with electrochemical cell as in situ interfacial sensitive tool to study corrosion inhibitors for magnesium substrates
- Author
-
Fockaert, L.I. (author), Würger, T. (author), Unbehau, R. (author), Boelen, B. (author), Meißner, R. H. (author), Lamaka, S. V. (author), Zheludkevich, M. L. (author), Terryn, H.A. (author), Mol, J.M.C. (author), Fockaert, L.I. (author), Würger, T. (author), Unbehau, R. (author), Boelen, B. (author), Meißner, R. H. (author), Lamaka, S. V. (author), Zheludkevich, M. L. (author), Terryn, H.A. (author), and Mol, J.M.C. (author)
- Abstract
Integrated attenuated total reflection – Fourier transform infrared spectroscopy (ATR-FTIR) – Electrochemical impedance spectroscopy (EIS) measurements were used to simultaneously follow chemisorption mechanisms of organic inhibitors as well as their corrosion inhibition efficiency towards magnesium based substrates. Four carboxylic compounds, i.e. 2,5-pyridinedicarboxylic acid (PDC), 3-methylsalicylic acid (MSA), sodium salicylate (SS) and fumaric acid (FA), were selected based on their promising inhibiting capacities and were all shown to chemisorb at the MgO/Mg(OH)2 surface by carboxylate bond formation. Orientation analysis using polarized infrared light showed that carboxylate bonds established using aliphatic carboxylate compound aligned perpendicular to the magnesium surface, whereas carboxylate bonds with aromatic compounds were oriented in plane with the magnesium surface. This different orientation is associated to the involvement of π-interactions in the MgO/Mg(OH)2 – aromatic carboxylate adsorption. Additionally, DFT calculations revealed that the addition of hetero-atoms (i.e. N or OH) in the molecular structure contributes to increased adsorption energies, indicating that next to carboxylate groups also these hetero-atoms are involved in interfacial interactions. Integrating the ATR-FTIR setup with an electrochemical cell allowing for simultaneous EIS measurements lead to two surface phenomena determining the inhibition efficiency. Surface hydroxylation processes on one hand forming a MgO/Mg(OH)2 layer on one hand, and the chemisorption of carboxylate compounds on the other hand. The inhibition efficiency was found to increase in following order: FA < PDC < MSA and was mainly associated to the formation of a MgO/Mg(OH)2 layer. SS was shown to act as a corrosion accelerator rather than a corrosion inhibitor. Despite its high sensitivity for water, both surface processes could be followed in situ by me, (OLD) MSE-6
- Published
- 2020
- Full Text
- View/download PDF
5. Liver Fibrosis stage at baseline predicts outcome of metabolic surgery
- Author
-
Kienbacher, C, additional, Wakolbinger, M, additional, Traussnigg, S, additional, Kruschitz, R, additional, Würger, T, additional, Schindler, K, additional, Ferlitsch, A, additional, Prager, G, additional, Ludvik, B, additional, and Trauner, M, additional
- Published
- 2019
- Full Text
- View/download PDF
6. Upregulation of osteoprotegerin expression correlates with bone invasion and predicts poor clinical outcome in oral cancer
- Author
-
Russmueller, G. Moser, D. Würger, T. Wrba, F. Christopoulos, P. Kostakis, G. Seemann, R. Stadler, V. Wimmer, G. Kornek, G. Psyrri, A. Filipits, M. Perisanidis, C.
- Subjects
musculoskeletal diseases ,stomatognathic diseases - Abstract
Objectives We aimed to determine the prognostic significance of receptor activator of nuclear factor kappa-B ligand (RANKL), RANK and osteoprotegerin (OPG) in patients with oral squamous cell carcinoma (OSCC). Materials and methods The protein expression of RANKL, RANK and OPG was assessed by immunohistochemistry on pretreatment biopsies of 93 patients with locally advanced OSCC who received preoperative chemoradiotherapy (CRT). The primary endpoint was cancer-specific survival. Secondary endpoints were correlation of biomarkers with bone invasion and pathological tumor response. Kaplan-Meier curves and Cox regression models were used for survival analyses. Results A significantly higher OPG expression was demonstrated in patients with malignant bone invasion and non-responders to CRT as compared to patients without bone invasion and responders (p = 0.032 and p = 0.033, respectively). Multivariate analysis revealed that higher OPG expression was independently associated with shorter cancer-specific survival (p = 0.04). The expression status of RANKL and RANK was not significantly related to clinicopathological characteristics and had no impact on survival of OSCC patients. Conclusion Upregulation of OPG expression is associated with bone invasion, poor pathological tumor regression to neoadjuvant CRT, and worse long-term cancer-specific survival in patients with locally advanced OSCC. Our results indicate that OPG may be a novel prognostic biomarker in oral cancer. © 2014 Elsevier Ltd. All rights reserved.
- Published
- 2015
7. Verstärkte hepatische Expression neuer MicroRNA bei ABCB4-/- Mäusen im Langzeitmodell
- Author
-
Würger, T, primary, Churin, Y, additional, Roderfeld, M, additional, and Roeb, E, additional
- Published
- 2015
- Full Text
- View/download PDF
8. Direkte zytotoxische Effekte des Hepatitis B Virus Oberflächenproteins in der Leber
- Author
-
Churin, Y, primary, Würger, T, additional, Roderfeld, M, additional, Stiefel, J, additional, Reifenberg, K, additional, Mollenkopf, HJ, additional, Schröder, D, additional, Montalbano, R, additional, Ocker, M, additional, Glebe, D, additional, and Roeb, E, additional
- Published
- 2013
- Full Text
- View/download PDF
9. Osteoclasts on bone and dentin in vitro: Mechanism of degradation and comparison of resorption behaviour
- Author
-
Würger, T., primary, Roschger, P., additional, Zwettler, E., additional, Fratzl, P., additional, Rogers, M.J., additional, Klaushofer, K., additional, and Rumpler, M., additional
- Published
- 2012
- Full Text
- View/download PDF
10. HCRP1 expression status is a significant prognostic marker in oral and oropharyngeal cancer
- Author
-
Perisanidis, C, primary, Savarese‐Brenner, B, additional, Würger, T, additional, Wrba, F, additional, Huynh, A, additional, Schopper, C, additional, Kornek, G, additional, Selzer, E, additional, Ewers, R, additional, Psyrri, A, additional, Krainer, M, additional, and Filipits, M, additional
- Published
- 2012
- Full Text
- View/download PDF
11. HCRPI expression status is a significant prognostic marker in oral and oropharyngeal cancer.
- Author
-
Perisanidis, C, Savarese‐Brenner, B, Würger, T, Wrba, F, Huynh, A, Schopper, C, Kornek, G, Selzer, E, Ewers, R, Psyrri, A, Krainer, M, and Filipits, M
- Subjects
ACADEMIC medical centers ,MOUTH tumors ,CONFIDENCE intervals ,IMMUNOHISTOCHEMISTRY ,MULTIVARIATE analysis ,PROTEINS ,SURVIVAL analysis (Biometry) ,TUMOR markers ,U-statistics ,PROPORTIONAL hazards models ,DATA analysis software ,KAPLAN-Meier estimator ,PROGNOSIS ,DIAGNOSIS - Abstract
OBJECTIVE: The hepatocellular carcinoma-related protein 1 (HCRPI) is a key factor in the degradation of the epidermal growth factor receptor. In this study, we assessed the prognostic significance of HCRP1 expression in patients with oral and oropharyngeal squamous cell carcinoma (OOSCC). METHODS: HCRP1 expression was determined by immunohistochemistry on tissue biopsy sections of III patients with locally advanced OOSCC undergoing neo-adjuvant chemoradiotherapy followed by surgery. The Kaplan-Meier method and Cox regression models were used for survival analyses. RESULTS: Low HCRP1 expression was associated with poor recurrence-free survival (P = 0.046) and overall survival (P = 0.03). Multivariate analysis revealed that low HCRP1 expression remained an independent risk factor for relapse (HR 2.98, 95% CI 1.19-7.49, P = 0.02) and death (HR 3.04, 95% CI 1.19-7.79, P = 0.02). CONCLUSION: Low HCRP1 expression was found to be of adverse prognostic significance in patients with OOS-CC who received preoperative chemoradiotherapy. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
12. Microcracks and osteoclast resorption activity in vitro
- Author
-
Rumpler, M., Wuerger, T., Roschger, P., Zwettler, E., Peterlik, H., Fratzl, P., and Klaushofer, K.
- Published
- 2011
- Full Text
- View/download PDF
13. Transient dysfunction of leadless pacemaker system after cardioversion.
- Author
-
Nies M, Fluschnik N, Würger T, Nikorowitsch J, and Tönnis T
- Published
- 2023
- Full Text
- View/download PDF
14. Characteristics and Prognostic Relevance of Ventricular Arrhythmia in Patients with Myocarditis.
- Author
-
Kahle AK, Güde R, Schwarzl JM, Münkler P, Akbulak RÖ, Jahnke C, Bohnen S, Würger T, Schwarzl M, Willems S, Radunski UK, and Meyer C
- Abstract
Myocarditis is characterized by various clinical manifestations, with ventricular arrhythmia (VA) as a frequent symptom at initial presentation. Here, we investigated characteristics and prognostic relevance of VA in patients with myocarditis. The study population consisted of 76 patients with myocarditis, verified by biopsy and/or cardiac magnetic resonance (CMR) imaging, including 38 consecutive patients with VA (45 ± 3 years, 68% male) vs. 38 patients without VA (NVA) (38 ± 2 years, 84% male) serving as a control group. VA was monomorphic ventricular tachycardia in 55% of patients, premature ventricular complexes in 50% and ventricular fibrillation in 29%. The left ventricular ejection fraction at baseline was 47 ± 2% vs. 40 ± 3% in VA vs. NVA patients (p = 0.069). CMR showed late gadolinium enhancement more often in VA patients (94% vs. 69%; p = 0.016), incorporating 17.6 ± 1.8% vs. 8.2 ± 1.3% of myocardial mass (p < 0.001). Radiofrequency catheter ablation for VA was initially performed in nine (24%) patients, of whom five remained free from any recurrence over 24 ± 3 months. Taken together, in patients with myocarditis, reduced left ventricular ejection fraction does not predict VA occurrence but CMR shows late gadolinium enhancement more frequently and to a larger extent in VA than in NVA patients, potentially guiding catheter ablation as a reasonable treatment of VA in this population.
- Published
- 2022
- Full Text
- View/download PDF
15. Atomistic Insight into the Hydration States of Layered Double Hydroxides.
- Author
-
Li X, Würger T, Feiler C, Meißner RH, Serdechnova M, Blawert C, and Zheludkevich ML
- Abstract
Effective protective coatings are an essential component of lightweight engineering materials in a large variety of applications as they ensure structural integrity of the base material throughout its whole service life. Layered double hydroxides (LDHs) loaded with corrosion inhibitors depict a promising approach to realize an active corrosion protection for aluminum and magnesium. In this work, we employed a combination of density functional theory and molecular dynamics simulations to gain a deeper understanding of the influence of intercalated water content on the structure, the stability, and the anion-exchange capacity of four different LDH systems containing either nitrate, carbonate, or oxalate as potential corrosion inhibiting agents or chloride as a corrosion initiator. To quantify the structural change, we studied the atom density distribution, radial distribution function, and orientation of the intercalated anions. Additionally, we determined the stability of the LDH systems by calculating their respective hydration energies, hydrogen-bonded network connected to the intercalated water molecules, as well as the self-diffusion coefficients of the intercalated anions to provide an estimate for the probability of their release after intercalation. The obtained computational results suggest that the hydration state of LDHs has a significant effect on their key properties like interlayer spacing and self-diffusion coefficients of the intercalated anions. Furthermore, we conclude from our simulation results that a high self-diffusion coefficient which is linked to the mobility of the intercalated anions is vital for its release via an anion-exchange mechanism and to subsequently mitigate corrosion reactions. Furthermore, the presented theoretical study provides a robust force field for the computer-assisted design of further LDH-based active anticorrosion coatings., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)
- Published
- 2022
- Full Text
- View/download PDF
16. A first-principles analysis of the charge transfer in magnesium corrosion.
- Author
-
Würger T, Feiler C, Vonbun-Feldbauer GB, Zheludkevich ML, and Meißner RH
- Abstract
Magnesium is the lightest structural engineering material and bears high potential to manufacture automotive components, medical implants and energy storage systems. However, the practical use of untreated magnesium alloys is restricted as they are prone to corrosion. An essential prerequisite for the control or prevention of the degradation process is a deeper understanding of the underlying corrosion mechanisms. Prior investigations of the formation of gaseous hydrogen during the corrosion of magnesium indicated that the predominant mechanism for this process follows the Volmer-Heyrovský rather than the previously assumed Volmer-Tafel pathway. However, the energetic and electronic states of both reaction paths as well as the charge state of dissolved magnesium have not been fully unraveled yet. In this study, density functional theory calculations were employed to determine these parameters for the Volmer, Tafel and Heyrovský steps to gain a comprehensive understanding of the major corrosion mechanisms responsible for the degradation of magnesium.
- Published
- 2020
- Full Text
- View/download PDF
17. Prevalence of Liver Fibrosis and its Association with Non-invasive Fibrosis and Metabolic Markers in Morbidly Obese Patients with Vitamin D Deficiency.
- Author
-
Luger M, Kruschitz R, Kienbacher C, Traussnigg S, Langer FB, Schindler K, Würger T, Wrba F, Trauner M, Prager G, and Ludvik B
- Subjects
- Adult, Biomarkers blood, Biopsy, Fine-Needle, Female, Gastric Bypass, Humans, Liver Cirrhosis complications, Male, Metabolic Syndrome complications, Middle Aged, Non-alcoholic Fatty Liver Disease complications, Obesity, Morbid complications, Obesity, Morbid metabolism, Prevalence, Prospective Studies, Risk Factors, Vitamin D Deficiency complications, Liver Cirrhosis pathology, Metabolic Syndrome metabolism, Non-alcoholic Fatty Liver Disease pathology, Obesity, Morbid surgery, Vitamin D Deficiency metabolism
- Abstract
Background: Morbidly obese patients are at risk for non-alcoholic fatty liver disease (NAFLD) and vitamin D deficiency (VDD). Non-alcoholic steatohepatitis (NASH) is the progressive variant of NAFLD and can advance to fibrosis, cirrhosis, and liver cancer. We aimed to examine prevalence of liver fibrosis and its non-invasive predictors in bariatric patients with VDD (<75 nmol/l)., Methods: Baseline liver biopsy of a randomized controlled trial was performed in 46 patients with omega loop gastric bypass. Clinical, laboratory, and histological data were examined and tested with univariate and multivariable analysis., Results: In total, 80 % were females, aged 42 (SD 13) years with BMI 44 (4) kg/m(2). Twenty-six percent had diabetes mellitus (DM) and 44 % metabolic syndrome (MeS). Seventy-two percent had NASH, 11 % simple steatosis, and 17 % normal liver. In total, 30 % demonstrated significant fibrosis (F ≥ 2) with 9 % of advanced (F3) and 4 % cirrhosis (F4). Increased stages of fibrosis were primarily associated with higher levels of HOMA2-insulin resistance (IR), procollagen type I propeptide (P1NP), lower osteocalcin, albumin-corrected calcium, parathyroid hormone, vitamin D, male sex, and higher age. Other independent risk factors for advanced fibrosis were MeS (OR = 9.3 [0.99-87.5], p = 0.052) and DM (OR = 12.8 [1.2-137.4], p = 0.035). The fibrosis FIB-4 index <10.62 and NAFLD fibrosis score <-26.93 had a negative predictive value of 100 and 96 %, respectively., Conclusions: Liver fibrosis is frequent in morbidly obese patients with concurrent DM and/or MeS. Increased serum levels of IR, P1NP, lower osteocalcin, and VDD are clinically relevant predictors of fibrosis. Consequently, we suggest that patients with preoperative presence of these markers are at increased risk for liver fibrosis and should be monitored closely., Competing Interests: Compliance with Ethical StandardsInformed consent was obtained from each patient included in the study. The trial was approved by the local Ethical Committee of the Medical University of Vienna (Ref No.: 1899/2013) and the Austrian Competent Authority (Ref. No.: LCM-718280-0001) and conforms to the ethical guidelines of the 1975 Declaration of Helsinki [12]. Furthermore, the protocol was registered at clinicaltrials.gov (NCT02092376) and the European Clinical Trials Database (EudraCT: 2013-003546-16). The study methods are in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines for reporting randomized trials [13].DisclosuresThe authors ML, RK, CK, ST, FL, KS, TW, FW, and BL have no commercial associations that might be a conflict of interest in relation to this article. MT reports grants and personal fees from Albireo, Gilead, MSD, Falk, and Intercept, personal fees from Janssen and Novartis, and grants from Takeda outside the submitted work. In addition, MT is listed as a co-inventor in a patent on the Medical use of nor-UDCA licensed to Med Univ Graz. GP reports educational grant from Medtronic outside the submitted work.
- Published
- 2016
- Full Text
- View/download PDF
18. Clinical Neuropathology image 5-2016: nNeurofibrillary tangle-rich ganglioglioma.
- Author
-
Gelpi E, Höftberger R, Würger T, Kerschbaumer J, Freyschlag CF, Djurdjevic T, and Hainfellner JA
- Subjects
- Biomarkers, Tumor analysis, Brain Neoplasms diagnostic imaging, Female, Ganglioglioma diagnostic imaging, Humans, Immunohistochemistry, Incidental Findings, Magnetic Resonance Imaging, Middle Aged, Brain Neoplasms pathology, Ganglioglioma pathology, Neurofibrillary Tangles pathology
- Abstract
*Both authors contributed equally.
- Published
- 2016
- Full Text
- View/download PDF
19. The link between obesity and vitamin D in bariatric patients with omega-loop gastric bypass surgery - a vitamin D supplementation trial to compare the efficacy of postoperative cholecalciferol loading (LOAD): study protocol for a randomized controlled trial.
- Author
-
Luger M, Kruschitz R, Marculescu R, Haslacher H, Hoppichler F, Kallay E, Kienbacher C, Klammer C, Kral M, Langer F, Luger E, Prager G, Trauner M, Traussnigg S, Würger T, Schindler K, and Ludvik B
- Subjects
- Administration, Oral, Biomarkers blood, Cholecalciferol adverse effects, Clinical Protocols, Double-Blind Method, Drug Administration Schedule, Female, Gastric Bypass adverse effects, Humans, Male, Obesity diagnosis, Postoperative Care, Prospective Studies, Research Design, Time Factors, Treatment Outcome, Vitamin D analogs & derivatives, Vitamin D blood, Vitamin D Deficiency blood, Vitamin D Deficiency diagnosis, Cholecalciferol administration & dosage, Dietary Supplements adverse effects, Gastric Bypass methods, Obesity surgery, Vitamin D Deficiency drug therapy
- Abstract
Background: Beyond its classical role in calcium homoeostasis and bone metabolism, vitamin D deficiency has been found to be associated with several diseases, including diabetes, non-alcoholic fatty liver disease, and even obesity itself. Importantly, there are limited data on therapeutic strategies for vitamin D deficiency in bariatric patients, and the procedure-specific guidelines may not be sufficient. To improve long-term outcomes, nutritional screening and appropriate supplementation to prevent nutrient deficiencies are urgently needed. Therefore, the aim of this study is to examine effects and safety of a forced dosing regimen of vitamin D versus conventional dose supplementation on vitamin D levels and other parameters in bariatric patients., Methods/design: The study includes loading plus repeat dosing compared with repeated administration of vitamin D without a loading dose, according to guidelines, in a prospective, double-blind, randomized controlled trial. Up to a triple oral loading dose is given on day 1, then 2 and 4 weeks after surgery (100,000 IU dose each time), followed by an oral maintenance dose (3420 IU/day). The control group (n = 25) will receive placebo, followed by administration of a standard dose (3420 IU/day). We hypothesize that a significant increase in vitamin D levels will occur in patients in the treatment group (n = 25) by 24 weeks after surgery. Further measurements are aimed at evaluating changes in inflammation, bone turnover, insulin resistance, blood pressure, liver, mental health, and gut microbiota of patients undergoing omega-loop gastric bypass surgery. Furthermore, possible associations between concentrations of vitamin D, the involved enzymes, or vitamin D receptor in adipose and/or liver tissues will be determined., Discussion: To our knowledge, this trial is the first of its kind with this type of vitamin D supplementation in bariatric patients. Its major strength is the design and implementation of evaluation of influencing factors such as liver function, bone health, inflammation, insulin resistance, blood pressure, symptoms of depression, or microbiota. This alternative vitamin D dosing regimen has the potential to be a safe, fast, evidence-based treatment of vitamin D deficiency in bariatric patients. Owing to the increasing number of bariatric patients, it is also of interest to elucidate the link between obesity and vitamin D., Trial Registration: ClinicalTrials.gov identifier: NCT02092376 . Registered on 17 March 2014.
- Published
- 2015
- Full Text
- View/download PDF
20. Correction: pathological impact of hepatitis B virus surface proteins on the liver is associated with the host genetic background.
- Author
-
Churin Y, Roderfeld M, Stiefel J, Würger T, Schröder D, Matono T, Mollenkopf HJ, Montalbano R, Pompaiah M, Reifenberg K, Zahner D, Ocker M, Gerlich W, Glebe D, and Roeb E
- Published
- 2015
- Full Text
- View/download PDF
21. Mineral oil in human tissues, part II: characterization of the accumulated hydrocarbons by comprehensive two-dimensional gas chromatography.
- Author
-
Biedermann M, Barp L, Kornauth C, Würger T, Rudas M, Reiner A, Concin N, and Grob K
- Subjects
- Chromatography, Gas, Humans, Spleen metabolism, Adipose Tissue metabolism, Environmental Pollutants metabolism, Mineral Oil metabolism
- Abstract
Mineral oil hydrocarbons are by far the largest contaminant in the human body. Their composition differs from that in the mineral oils humans are exposed to, and varies also between different tissues of the same individual. Using the presently best technique for characterizing the composition of mineral oil hydrocarbons, comprehensive two-dimensional gas chromatography (GC×GC), the hydrocarbons in human tissues were compared to those of various mineral oils. This provided information about the strongly accumulated species and might give hints on the flow path through the human body. The selectivity of accumulation is probably also of interest for the risk assessment of synthetic hydrocarbons (polyolefins). GC×GC grouped the MOSH into classes of n-alkanes, paraffins with a low degree of branching, multibranched paraffins and naphthenes (alkylated cyclic hydrocarbons) with 1-4 rings. Metabolic elimination was observed for constituents of all these classes, but was selective within each class. The MOSH in the subcutaneous abdominal fat tissues and the mesenteric lymph nodes (MLN) had almost the same composition and included the distinct signals observed in mineral oil, though in reduced amounts relative to the cloud of unresolved hydrocarbons. The MOSH in the liver and the spleen were different from those in the MLN and fat tissue, but again with largely identical composition for a given individual. Virtually all constituents forming distinct signals were eliminated, leaving an unresolved residue of highly isomerized hydrocarbons., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
22. Pathological impact of hepatitis B virus surface proteins on the liver is associated with the host genetic background.
- Author
-
Churin Y, Roderfeld M, Stiefel J, Würger T, Schröder D, Matono T, Mollenkopf HJ, Montalbano R, Pompaiah M, Reifenberg K, Zahner D, Ocker M, Gerlich W, Glebe D, and Roeb E
- Subjects
- Animals, Female, Gene Expression Regulation, Hepatitis B metabolism, Hepatitis B pathology, Liver metabolism, Liver Cirrhosis etiology, Liver Cirrhosis genetics, Liver Neoplasms etiology, Liver Neoplasms genetics, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Transgenic, Phosphorylation, Signal Transduction, eIF-2 Kinase metabolism, Hepatitis B complications, Hepatitis B genetics, Hepatitis B virus physiology, Host-Pathogen Interactions, Liver pathology, Liver virology, Viral Structural Proteins genetics
- Abstract
Background: While the immune pathogenesis caused by hepatitis B virus (HBV) infection has been studied extensively, little is known about direct pathogenic effects of HBV surface proteins. Here, we have investigated pathological cellular effects of HBV surface protein expression in the liver of transgenic mice with different genetic background., Methods: The impact of HBV surface protein expression on the liver was studied in two mouse strains, BALB/c and C57BL/6. Histology and hydroxyproline assays were performed to investigate liver morphology and fibrosis. Gene expression and signaling were analyzed by microarray, qPCR and Western blotting., Results: Expression of HBV surface proteins in the liver of transgenic mice induced activation of protein kinase-like endoplasmic reticulum kinase (PERK) and eukaryotic initiation factor 2α (eIF2α) phosphorylation. Phosphorylation of eIF2α resulted in activation of the ER stress markers glucose regulated protein (GRP) 78 and pro-apoptotic C/EBP homologous protein (CHOP) in transgenic mice on BALB/c genetic background leading to stronger liver injury and fibrosis in comparison with transgenic mice on C57BL/6 background. Hepatic stellate cells represented the main collagen-producing liver cells in HBV transgenic mice. The key regulators of hepatocyte proliferation, transcription factors c-Jun and STAT3 were activated in HBV transgenic mice. Tumour incidence in transgenic mice was strain- and sex-dependent., Conclusions: Extent of liver injury, fibrosis, and tumour development induced by hepatic HBV surface protein expression considerably depends on host genetic background.
- Published
- 2014
- Full Text
- View/download PDF
23. Microcracks and osteoclast resorption activity in vitro.
- Author
-
Rumpler M, Würger T, Roschger P, Zwettler E, Peterlik H, Fratzl P, and Klaushofer K
- Subjects
- Bone Matrix cytology, Bone Matrix metabolism, Bone Regeneration physiology, Bone and Bones cytology, Collagen metabolism, Dentin cytology, Dentin metabolism, Fractures, Bone physiopathology, Humans, Osteoclasts cytology, Osteocytes metabolism, Primary Cell Culture, Bone Remodeling physiology, Bone Resorption metabolism, Bone and Bones metabolism, Fractures, Bone metabolism, Osteoclasts metabolism
- Abstract
During bone remodeling osteoclasts resorb bone, thus removing material, e.g., damaged by microcracks, which arises as a result of physiological loading and could reduce bone strength. Such a process needs targeted bone resorption exactly at damaged sites. Osteocytic signaling plays a key role in this process, but it is not excluded that osteoclasts per se may possess toposensitivity to recognize and resorb damaged bone since it has been shown that resorption spaces are associated with microcracks. To address this question, we used an in vitro setup of a pure osteoclast culture and mineralized substrates with artificially introduced microcracks and microscratches. Histomorphometric analyses and statistical evaluation clearly showed that these defects had no effect on osteoclast resorption behavior. Osteoclasts did not resorb along microcracks, even when resorption started right beside these damages. Furthermore, quantification of resorption on three different mineralized substrates, cortical bone, bleached bone (bone after partial removal of the organic matrix), and dentin, revealed lowest resorption on bone, significantly higher resorption on bleached bone, and highest resorption on dentin. The difference between native and bleached bone may be interpreted as an inhibitory impact of the organic matrix. However, the collagen-based matrix could not be the responsible part as resorption was highest on dentin, which contains collagen. It seems that osteocytic proteins, stored in bone but not present in dentin, affect osteoclastic action. This demonstrates that osteoclasts per se do not possess a toposensitivity to remove microcracks but may be influenced by components of the organic bone matrix.
- Published
- 2012
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.