36 results on '"Schuch K"'
Search Results
2. Polo-like kinase-1 (Plk-1) is expressed in neoplastic mast cells and is a potential new target in advanced systemic mastocytosis: V691
- Author
-
Peter, B., Gleixner, K. V., Cerny-Reiterer, S., Herrmann, H., Hadzijusufovic, E., Ferenc, V., Winter, V., Schuch, K., Willmann, M., Pickl, W. F., and Valent, P.
- Published
- 2010
3. Der Nachweis eines Virusgemisches in einer enationenkranken Süßkirsche
- Author
-
Schuch, K. and Mischke, W.
- Published
- 1960
4. Das Ring- und Bandmosaik der Süßkirsche
- Author
-
Schuch, K.
- Published
- 1959
5. Einiges über die Erdbeerblattlaus Pentatrichopus fragaefolii Cock
- Author
-
Schuch, K.
- Published
- 1955
6. Eine Klimatisierungseinrichtung für das Studium ökologischer Fragen bei Holzschädlingen
- Author
-
Schuch, K.
- Published
- 1952
7. Richtlinien für die Bekämpfung des Maikäfers in der schleswigholsteinischen Knicklandschaft unter Verwertung von Erfahrungen aus dem Flugjahr 1934
- Author
-
Schuch, K.
- Published
- 1935
- Full Text
- View/download PDF
8. Zur Hausbockkäferbekämpfung
- Author
-
Schuch, K.
- Published
- 1939
- Full Text
- View/download PDF
9. Über die Bestimmung des Fluors im Holz
- Author
-
Schuch, K.
- Published
- 1953
- Full Text
- View/download PDF
10. Die dem Obstbau durch Viruskrankheiten drohende Gefahr und ihre Abwehr
- Author
-
Schuch, K.
- Published
- 1958
- Full Text
- View/download PDF
11. Polo-like kinase-1 as a novel target in neoplastic mast cells: demonstration of growth-inhibitory effects of small interfering RNA and the Polo-like kinase-1 targeting drug BI 2536
- Author
-
Peter, B., primary, Gleixner, K. V., additional, Cerny-Reiterer, S., additional, Herrmann, H., additional, Winter, V., additional, Hadzijusufovic, E., additional, Ferenc, V., additional, Schuch, K., additional, Mirkina, I., additional, Horny, H.-P., additional, Pickl, W. F., additional, Mullauer, L., additional, Willmann, M., additional, and Valent, P., additional
- Published
- 2011
- Full Text
- View/download PDF
12. Mangan
- Author
-
Muller, J. A., Centnerszwer, M., Szedrowicz, J., Walde, H., and Schuch, K. A.
- Published
- 1942
- Full Text
- View/download PDF
13. NI-1: a novel canine mastocytoma model for studying drug resistance and Ig ER-dependent mast cell activation.
- Author
-
Hadzijusufovic, E., Peter, B., Herrmann, H., Rülicke, T., Cerny-Reiterer, S., Schuch, K., Kenner, L., Thaiwong, T., Yuzbasiyan-Gurkan, V., Pickl, W. F., Willmann, M., and Valent, P.
- Subjects
MAST cell tumors ,GENETIC mutation ,EXONS (Genetics) ,DRUG resistance in cancer cells ,PROTEIN-tyrosine kinases ,ENZYME inhibitors ,CELL differentiation ,RAPAMYCIN ,TARGETED drug delivery - Abstract
Background Advanced mast cell ( MC) disorders are characterized by uncontrolled growth of neoplastic MC in various organs, mediator-related symptoms, and a poor prognosis. Kit mutations supposedly contribute to abnormal growth and drug resistance in these patients. Methods We established a novel canine mastocytoma cell line, NI-1, from a patient suffering from MC leukemia. Results NI-1 cells were found to form mastocytoma lesions in NOD/ SCID IL-2 Rgamma
null mice and to harbor several homozygous Kit mutations, including missense mutations at nucleotides 107( C→ T) and 1187( A→ G), a 12-bp duplication (nucleotide 1263), and a 12-bp deletion (nucleotide 1550). NI-1 cells expressed several MC differentiation antigens, including tryptase, Kit, and a functional Ig E receptor. Compared to the C2 mastocytoma cell line harboring a Kit exon 11 mutation, NI-1 cells were found to be less responsive against the Kit tyrosine kinase inhibitors ( TKI) masitinib and imatinib, but were even more sensitive against proliferation-inhibitory effects of the mammalian target of rapamycin ( mTOR) blocker RAD001 and PI3-kinase/ mTOR blocker NVP- BEZ235. The Kit-targeting multikinase inhibitors PKC412 and dasatinib were also found to override TKI resistance in NI-1 cells, and produced growth inhibition with reasonable IC50 values (<0.1 μM). Conclusion NI-1 may serve as a useful tool to investigate Ig E-dependent reactions and mechanisms of abnormal growth and drug resistance in neoplastic MC in advanced mastocytosis. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
14. Untersuchungen über eine viröse Triebtachung des Pfirsichs.
- Author
-
Mischke, W. and Schuch, K.
- Published
- 1962
- Full Text
- View/download PDF
15. Untersuchungen über die Triebsucht des Apfels.
- Author
-
Schuch, K.
- Published
- 1961
- Full Text
- View/download PDF
16. Zur Methodik der Fluorbestimmung in der Holzschutzforschung.
- Author
-
Schuch, K.
- Published
- 1953
17. Untersuchungen über den quantitativen Nachweis der Feuerschutzmittel auf Phosphatbasis.
- Author
-
Schuch, K.
- Published
- 1951
18. Der Nachweis des cherry leaf-roll virus in einer pfeffingerkranken Süßkirsche
- Author
-
Mischke, W., primary and Schuch, K., additional
- Published
- 1963
- Full Text
- View/download PDF
19. Viruskrankheiten und aũnliche Erscheinungen bei Obstgewächsen
- Author
-
SCHUCH, K., primary
- Published
- 1958
- Full Text
- View/download PDF
20. Towards the modeling of dissociated cortical tissue in the liquid state machine framework.
- Author
-
Goswami, D., Schuch, K., Yi Zheng, DeMarse, T., and Principe, J.C.
- Published
- 2005
- Full Text
- View/download PDF
21. Extracellular Vesicles May Predict Response to Atezolizumab Plus Bevacizumab in Patients with Advanced Hepatocellular Carcinoma.
- Author
-
Egerer M, Schuch K, Schöler D, Artusa F, Püngel T, Holtman TM, Loosen SH, Demir M, Wree A, Luedde T, Tacke F, Roderburg C, and Mohr R
- Abstract
Background and Aims: Treatment with atezolizumab and bevacizumab has been approved as one of the standards of care for patients with advanced hepatocellular carcinoma (HCC). The median overall survival (OS) upon available treatments still remains below 2 years, urgently suggesting better stratification tools to identify ideal candidates for this treatment and potentially allowing personalized approaches. In this study, we evaluated the potential role of extracellular vesicles (EVs) as a novel biomarker in patients receiving atezolizumab and bevacizumab for HCC., Methods: We characterized EVs in 212 longitudinal serum samples from an observational cohort of 53 individuals with advanced HCC, who started therapy with atezolizumab plus bevacizumab at our center between January 2020 and March 2022., Results: In our cohort, the overall efficacy of atezolizumab and bevacizumab was comparable to previously published phase III data. We detected significantly smaller EVs in treatment responders, while enlarged EVs were associated with significantly decreased efficacy of atezolizumab and bevacizumab in terms of OS. A decrease in vesicle size during immunotherapy was related to a longer progression-free survival (PFS). A univariate Cox regression analysis including various clinicopathological parameters (e.g., tumor stage, markers of inflammation, organ dysfunction, or tumor markers) revealed vesicle size as an independent prognostic marker in HCC patients receiving atezolizumab and bevacizumab. Moreover, higher vesicle concentrations and lower zeta potentials were identified as a positive prognostic factor throughout treatment., Conclusions: Distinct EV characteristics such as vesicle size, concentration, and zeta potential represent promising novel biomarkers in patients with advanced HCC receiving atezolizumab and bevacizumab, potentially helping to identify optimal candidates for checkpoint inhibitor-based treatments.
- Published
- 2024
- Full Text
- View/download PDF
22. Clinical Application of ISO and CEN/TS Standards for Liquid Biopsies-Information Everybody Wants but Nobody Wants to Pay For.
- Author
-
Bonstingl L, Skofler C, Ulz C, Zinnegger M, Sallinger K, Schönberger J, Schuch K, Pankratz K, Borrás-Cherrier A, Somodi V, Abuja PM, Oberauner-Wappis L, Moser T, Heitzer E, Bauernhofer T, Kroneis T, and El-Heliebi A
- Subjects
- Humans, Liquid Biopsy standards, Male, Biomarkers, Tumor blood, Prostatic Neoplasms pathology, Neoplastic Cells, Circulating pathology, Circulating Tumor DNA blood, Hemolysis
- Abstract
Background: Liquid biopsies are emerging as valuable clinical biomarkers for cancer monitoring. Although International Organization for Standards (ISO) and Technical Specifications from the European Committee for Standardization (CEN/TS) standardized workflows exist, their implementation in clinical practice is underdeveloped. We aimed to assess the applicability of ISO and CEN/TS standards in a real-world clinical setting, with a particular focus on evaluating the impact of preanalytical parameters and hemolysis on liquid biopsy analysis., Methods: We evaluated 659 peripheral blood samples from advanced prostate cancer patients against ISO and CEN/TS standards and documented all essential criteria, including tube draw order, filling level, temperature, and time tracking from blood draw to storage. We assessed hemolysis and its effect on circulating tumor DNA (ctDNA) and circulating tumor cell (CTC) analysis., Results: Our results demonstrated a high compliance rate, with 96.2% (634/659) of samples meeting essential ISO and CEN/TS criteria. We did not observe a significant impact on ctDNA or CTC detection rates between hemolytic and nonhemolytic samples. Hemolysis was identified in 12.9% (40/311) of plasma samples from our advanced prostate cancer cohort, and within the draw order of 5 blood collection tubes, hemolysis did not significantly increase from tube 1 to 5. In total, 83.8% (552/659) of blood collection tubes had high fill levels above 80% of nominal filling level., Conclusions: Our study demonstrates the feasibility and benefits of adhering to ISO and CEN/TS standards in a clinical liquid biopsy study. The standards revealed that hemolysis occurred frequently but did not impair downstream ctDNA and CTC analysis in our cohort of advanced prostate cancer patients., (© Association for Diagnostics & Laboratory Medicine 2024.)
- Published
- 2024
- Full Text
- View/download PDF
23. Disrupted autophagy and neuronal dysfunction in C. elegans knockin models of FUS amyotrophic lateral sclerosis.
- Author
-
Baskoylu SN, Chapkis N, Unsal B, Lins J, Schuch K, Simon J, and Hart AC
- Subjects
- Amyotrophic Lateral Sclerosis pathology, Animals, Caenorhabditis elegans, Disease Models, Animal, Gene Knock-In Techniques, Mutation, Amyotrophic Lateral Sclerosis genetics, Amyotrophic Lateral Sclerosis physiopathology, Autophagy physiology, Motor Neurons pathology, RNA-Binding Protein FUS genetics
- Abstract
How mutations in FUS lead to neuronal dysfunction in amyotrophic lateral sclerosis (ALS) patients remains unclear. To examine mechanisms underlying ALS FUS dysfunction, we generate C. elegans knockin models using CRISPR-Cas9-mediated genome editing, creating R524S and P525L ALS FUS models. Although FUS inclusions are not detected, ALS FUS animals show defective neuromuscular function and locomotion under stress. Unlike animals lacking the endogenous FUS ortholog, ALS FUS animals have impaired neuronal autophagy and increased SQST-1 accumulation in motor neurons. Loss of sqst-1, the C. elegans ortholog for ALS-linked, autophagy adaptor protein SQSTM1/p62, suppresses both neuromuscular and stress-induced locomotion defects in ALS FUS animals, but does not suppress neuronal autophagy defects. Therefore, autophagy dysfunction is upstream of, and not dependent on, SQSTM1 function in ALS FUS pathogenesis. Combined, our findings demonstrate that autophagy dysfunction likely contributes to protein homeostasis and neuromuscular defects in ALS FUS knockin animals., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
24. Single copy/knock-in models of ALS SOD1 in C. elegans suggest loss and gain of function have different contributions to cholinergic and glutamatergic neurodegeneration.
- Author
-
Baskoylu SN, Yersak J, O'Hern P, Grosser S, Simon J, Kim S, Schuch K, Dimitriadi M, Yanagi KS, Lins J, and Hart AC
- Subjects
- Amino Acid Sequence, Amyotrophic Lateral Sclerosis pathology, Animals, Animals, Genetically Modified, Base Sequence, CRISPR-Cas Systems, Cholinergic Neurons metabolism, Disease Models, Animal, Gain of Function Mutation, Gene Frequency, Gene Knock-In Techniques, Glutamic Acid metabolism, Humans, Loss of Function Mutation, Motor Neurons metabolism, Amyotrophic Lateral Sclerosis genetics, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins genetics, Cholinergic Neurons pathology, Motor Neurons pathology, Superoxide Dismutase genetics, Superoxide Dismutase-1 genetics
- Abstract
Mutations in Cu/Zn superoxide dismutase 1 (SOD1) lead to Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease that disproportionately affects glutamatergic and cholinergic motor neurons. Previous work with SOD1 overexpression models supports a role for SOD1 toxic gain of function in ALS pathogenesis. However, the impact of SOD1 loss of function in ALS cannot be directly examined in overexpression models. In addition, overexpression may obscure the contribution of SOD1 loss of function in the degeneration of different neuronal populations. Here, we report the first single-copy, ALS knock-in models in C. elegans generated by transposon- or CRISPR/Cas9- mediated genome editing of the endogenous sod-1 gene. Introduction of ALS patient amino acid changes A4V, H71Y, L84V, G85R or G93A into the C. elegans sod-1 gene yielded single-copy/knock-in ALS SOD1 models. These differ from previously reported overexpression models in multiple assays. In single-copy/knock-in models, we observed differential impact of sod-1 ALS alleles on glutamatergic and cholinergic neurodegeneration. A4V, H71Y, G85R, and G93A animals showed increased SOD1 protein accumulation and oxidative stress induced degeneration, consistent with a toxic gain of function in cholinergic motor neurons. By contrast, H71Y, L84V, and G85R lead to glutamatergic neuron degeneration due to sod-1 loss of function after oxidative stress. However, dopaminergic and serotonergic neuronal populations were spared in single-copy ALS models, suggesting a neuronal-subtype specificity previously not reported in invertebrate ALS SOD1 models. Combined, these results suggest that knock-in models may reproduce the neurotransmitter-type specificity of ALS and that both SOD1 loss and gain of toxic function differentially contribute to ALS pathogenesis in different neuronal populations., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
- Full Text
- View/download PDF
25. Osteopontin affects macrophage polarization promoting endocytic but not inflammatory properties.
- Author
-
Schuch K, Wanko B, Ambroz K, Castelo-Rosa A, Moreno-Viedma V, Grün NG, Leitner L, Staffler G, Zeyda M, and Stulnig TM
- Subjects
- Adipocytes physiology, Adipose Tissue metabolism, Animals, Diet, High-Fat, Inflammation physiopathology, Insulin Resistance, Male, Mice, Mice, Inbred C57BL, Phagocytosis physiology, Phenotype, Tumor Necrosis Factor-alpha metabolism, Macrophages physiology, Obesity physiopathology, Osteopontin metabolism
- Abstract
Objective: Macrophages are the main drivers of obesity-induced adipose tissue (AT) inflammation that causes insulin resistance. Macrophages polarize toward different inflammatory (M1) or protective (M2) phenotypes. Osteopontin (OPN) is an inflammatory cytokine highly expressed in AT in obesity and known to be involved in chronic inflammatory processes. It was hypothesized that OPN polarizes macrophages into a proinflammatory phenotype., Methods: AT macrophages (ATMs) of OPN-deficient (Spp1(-/-) ) and wild-type C57BL/6 (WT) mice with obesity and bone marrow-derived macrophages (BMDMs) of Spp1(-/-) and WT mice as well as human monocyte-derived macrophages (MDMs) polarized in the presence of OPN were investigated., Results: While ATM infiltration was lower in Spp1(-/-) upon high-fat diet, Spp1(-/-) ATMs expressed more M1 and less M2 markers but less tumor necrosis factor-α compared with WT. There was no effect of OPN deficiency on BMDM polarization. In human MDMs, the presence of OPN during polarization ambiguously altered M1/M2-related marker expression and diminished LPS-induced inflammatory cytokine production. Strikingly, phagocytic activity was elevated by the presence of OPN during polarization in both human MDMs and murine BMDMs., Conclusions: In contradiction to our hypothesis, data indicated that OPN does not induce inflammatory macrophages but was a signal to induce phagocytosis, which may be required due to increased adipocyte death in obesity., (© 2016 The Obesity Society.)
- Published
- 2016
- Full Text
- View/download PDF
26. Immunological blockade of adipocyte inflammation caused by increased matrix metalloproteinase-cleaved osteopontin in obesity.
- Author
-
Leitner L, Schuch K, Jürets A, Itariu BK, Keck M, Grablowitz V, Aszmann OC, Prager G, Staffler G, Zeyda M, and Stulnig TM
- Subjects
- Adipose Tissue metabolism, Humans, Insulin Resistance, Obesity physiopathology, Obesity prevention & control, Adipocytes metabolism, Matrix Metalloproteinase 9 metabolism, Obesity immunology, Osteopontin metabolism
- Abstract
Objective: Osteopontin (OPN) is upregulated in adipose tissue (AT) in obesity and contributes to subclinical inflammation, adipocyte dysfunction, and insulin resistance. OPN effects can be increased by cleavage by matrix metalloproteinases (MMP). This study aimed at investigating the presence of OPN cleavage products in human AT in obesity and their impact on adipocyte function and immunological blockade of these effects., Methods: AT of severely obese and control donors was investigated for OPN and MMP expression and the presence of OPN cleavage fragments. Primary adipocytes were isolated from human donors for in vitro investigation of cleaved OPN effects., Results: OPN and MMP-9 expression was highly correlated in AT from obese donors, and increased levels of cleaved OPN were detected in AT from obese individuals. The in vitro effect of OPN on adipocyte inflammation and insulin resistance was enhanced by protease cleavage, which could finally be blocked with a monoclonal antibody directed against the MMP cleavage site of OPN., Conclusions: These findings show that MMP cleavage of OPN in AT occurs in obesity, thereby enhancing OPN's inflammatory and pro-diabetic activity on adipocytes. Specifically targeting MMP-cleaved OPN opens avenues for prevention and treatment of obesity-induced type 2 diabetes., (© 2015 The Obesity Society.)
- Published
- 2015
- Full Text
- View/download PDF
27. The pan-Bcl-2 blocker obatoclax promotes the expression of Puma, Noxa, and Bim mRNA and induces apoptosis in neoplastic mast cells.
- Author
-
Peter B, Cerny-Reiterer S, Hadzijusufovic E, Schuch K, Stefanzl G, Eisenwort G, Gleixner KV, Hoermann G, Mayerhofer M, Kundi M, Baumgartner S, Sperr WR, Pickl WF, Willmann M, and Valent P
- Subjects
- Adult, Aged, Aged, 80 and over, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Bcl-2-Like Protein 11, Cell Line, Tumor, Cell Proliferation drug effects, Drug Resistance, Neoplasm genetics, Drug Synergism, Female, Humans, Indoles, Male, Mast-Cell Sarcoma drug therapy, Mast-Cell Sarcoma mortality, Middle Aged, Myeloid Cell Leukemia Sequence 1 Protein genetics, Pyrroles therapeutic use, RNA, Messenger genetics, bcl-X Protein genetics, Apoptosis drug effects, Apoptosis Regulatory Proteins genetics, Gene Expression Regulation, Neoplastic drug effects, Mast-Cell Sarcoma genetics, Membrane Proteins genetics, Proto-Oncogene Proteins genetics, Proto-Oncogene Proteins c-bcl-2 genetics, Pyrroles pharmacology
- Abstract
Advanced SM is an incurable neoplasm with short survival time. So far, no effective therapy is available for these patients. We and others have shown recently that neoplastic MC in ASM and MCL express antiapoptotic Mcl-1, Bcl-2, and Bcl-xL. In this study, we examined the effects of the pan-Bcl-2 family blocker obatoclax (GX015-070) on primary neoplastic MC, the human MC leukemia cell line HMC-1, and the canine mastocytoma cell line C2. Obatoclax was found to inhibit proliferation in primary human neoplastic MC (IC₅₀: 0.057 μM), in HMC-1.2 cells expressing KIT D816V (IC₅₀: 0.72 μM), and in HMC-1.1 cells lacking KIT D816V (IC₅₀: 0.09 μM), as well as in C2 cells (IC₅₀: 0.74 μM). The growth-inhibitory effects of obatoclax in HMC-1 cells were accompanied by an increase in expression of Puma, Noxa, and Bim mRNA, as well as by apoptosis, as evidenced by microscopy, TUNEL assay, and caspase cleavage. Viral-mediated overexpression of Mcl-1, Bcl-xL, or Bcl-2 in HMC-1 cells was found to introduce partial resistance against apoptosis-inducing effects of obatoclax. We were also able to show that obatoclax synergizes with several other antineoplastic drugs, including dasatinib, midostaurin, and bortezomib, in producing apoptosis and/or growth arrest in neoplastic MC. Together, obatoclax exerts major growth-inhibitory effects on neoplastic MC and potentiates the antineoplastic activity of other targeted drugs. Whether these drug effects can be translated to application in patients with advanced SM remains to be determined.
- Published
- 2014
- Full Text
- View/download PDF
28. 5-azacytidine and decitabine exert proapoptotic effects on neoplastic mast cells: role of FAS-demethylation and FAS re-expression, and synergism with FAS-ligand.
- Author
-
Ghanim V, Herrmann H, Heller G, Peter B, Hadzijusufovic E, Blatt K, Schuch K, Cerny-Reiterer S, Mirkina I, Karlic H, Pickl WF, Zöchbauer-Müller S, and Valent P
- Subjects
- Adult, Aged, Base Sequence, Cell Line, Tumor drug effects, CpG Islands, DNA Methylation drug effects, DNA, Neoplasm metabolism, Decitabine, Drug Synergism, Fas Ligand Protein physiology, Female, Humans, Male, Mast Cells pathology, Methylation drug effects, Middle Aged, Molecular Sequence Data, Neoplasm Proteins metabolism, Point Mutation, Promoter Regions, Genetic genetics, Proto-Oncogene Proteins c-kit genetics, RNA, Small Interfering pharmacology, fas Receptor antagonists & inhibitors, fas Receptor genetics, Antimetabolites, Antineoplastic pharmacology, Apoptosis drug effects, Azacitidine analogs & derivatives, Azacitidine pharmacology, Leukemia, Mast-Cell pathology, Mast Cells drug effects, Mastocytosis, Systemic pathology, Protein Processing, Post-Translational drug effects, fas Receptor metabolism
- Abstract
Aggressive systemic mastocytosis (ASM) and mast cell leukemia (MCL) are advanced hematopoietic neoplasms with poor prognosis. In these patients, neoplastic mast cells (MCs) are resistant against various drugs. We examined the effects of 2 demethylating agents, 5-azacytidine and decitabine on growth and survival of neoplastic MCs and the MC line HMC-1. Two HMC-1 subclones were used, HMC-1.1 lacking KIT D816V and HMC-1.2 exhibiting KIT D816V. Both agents induced apoptosis in HMC-1.1 and HMC-1.2 cells. Decitabine, but not 5-azacytidine, also produced a G(2)/M cell-cycle arrest in HMC-1 cells. Drug-induced apoptosis was accompanied by cleavage of caspase-8 and caspase-3 as well as FAS-demethylation and FAS-re-expression in neoplastic MCs. Furthermore, both demethylating agents were found to synergize with the FAS-ligand in inducing apoptosis in neoplastic MCs. Correspondingly, siRNA against FAS was found to block drug-induced expression of FAS and drug-induced apoptosis in HMC-1 cells. Neither 5-azacytidine nor decitabine induced substantial apoptosis or growth arrest in normal MCs or normal bone marrow cells. Together, 5-azacytidine and decitabine exert growth-inhibitory and proapoptotic effects in neoplastic MCs. These effects are mediated through "FAS-re-expression" and are augmented by the FAS-ligand. Whether epigenetic drugs produce antineoplastic effects in vivo in patients with ASM and MCL remains to be determined.
- Published
- 2012
- Full Text
- View/download PDF
29. Human TCR transgenic Bet v 1-specific Th1 cells suppress the effector function of Bet v 1-specific Th2 cells.
- Author
-
Neunkirchner A, Leb-Reichl VM, Schmetterer KG, Mutschlechner S, Kueng HJ, Haiderer D, Schuch K, Wallner M, Jahn-Schmid B, Bohle B, and Pickl WF
- Subjects
- Amino Acid Sequence, Base Sequence, Cell Separation, Cross Reactions immunology, Flow Cytometry, Fluorescent Antibody Technique, Food Hypersensitivity immunology, HEK293 Cells, Humans, Immunodominant Epitopes immunology, Jurkat Cells, Lymphocyte Activation immunology, Molecular Sequence Data, Receptors, Antigen, T-Cell, alpha-beta genetics, Reverse Transcriptase Polymerase Chain Reaction, Transduction, Genetic, Transgenes, Antigens, Plant immunology, Receptors, Antigen, T-Cell, alpha-beta immunology, Rhinitis, Allergic, Seasonal immunology, Th1 Cells immunology, Th2 Cells immunology
- Abstract
Pollinosis to birch pollen is a common type I allergy in the Northern Hemisphere. Moreover, birch pollen-allergic individuals sensitized to the major birch pollen allergen Bet v 1 frequently develop allergic reactions to stone fruits, hazelnuts, and certain vegetables due to immunological cross-reactivity. The major T cell epitope Bet v 1(142-153) plays an important role in cross-reactivity between the respiratory allergen Bet v 1 and its homologous food allergens. In this study, we cloned and functionally analyzed a human αβ TCR specific for the immunodominant epitope Bet v 1(142-153). cDNAs encoding TCR α- and β-chains were amplified from a Bet v 1(142-153)-specific T cell clone, introduced into Jurkat T cells and peripheral blood T lymphocytes of allergic and nonallergic individuals, and evaluated functionally. The resulting TCR transgenic (TCRtg) T cells responded in an allergen-specific and costimulation-dependent manner to APCs either pulsed with Bet v 1(142-153) peptide or coexpressing invariant chain::Bet v 1(142-153) fusion proteins. TCRtg T cells responded to Bet v 1-related food and tree pollen allergens that were processed and presented by monocyte-derived dendritic cells. Bet v 1(142-153)-presenting but not Bet v 1(4-15)-presenting artificial APCs coexpressing membrane-bound IL-12 polarized allergen-specific TCRtg T cells toward a Th1 phenotype, producing high levels of IFN-γ. Coculture of such Th1-polarized T cells with allergen-specific Th2-differentiated T cells significantly suppressed Th2 effector cytokine production. These data suggest that human allergen-specific TCR can transfer the fine specificity of the original T cell clone to heterologous T cells, which in turn can be instructed to modulate the effector function of the disease initiating/perpetuating allergen-specific Th2-differentiated T cells.
- Published
- 2011
- Full Text
- View/download PDF
30. Statistical comparison of spike responses to natural stimuli in monkey area V1 with simulated responses of a detailed laminar network model for a patch of V1.
- Author
-
Rasch MJ, Schuch K, Logothetis NK, and Maass W
- Subjects
- Animals, Computer Simulation, Data Interpretation, Statistical, Macaca mulatta, Models, Statistical, Action Potentials physiology, Evoked Potentials, Visual physiology, Models, Neurological, Nerve Net physiology, Visual Cortex physiology, Visual Perception physiology
- Abstract
A major goal of computational neuroscience is the creation of computer models for cortical areas whose response to sensory stimuli resembles that of cortical areas in vivo in important aspects. It is seldom considered whether the simulated spiking activity is realistic (in a statistical sense) in response to natural stimuli. Because certain statistical properties of spike responses were suggested to facilitate computations in the cortex, acquiring a realistic firing regimen in cortical network models might be a prerequisite for analyzing their computational functions. We present a characterization and comparison of the statistical response properties of the primary visual cortex (V1) in vivo and in silico in response to natural stimuli. We recorded from multiple electrodes in area V1 of 4 macaque monkeys and developed a large state-of-the-art network model for a 5 × 5-mm patch of V1 composed of 35,000 neurons and 3.9 million synapses that integrates previously published anatomical and physiological details. By quantitative comparison of the model response to the "statistical fingerprint" of responses in vivo, we find that our model for a patch of V1 responds to the same movie in a way which matches the statistical structure of the recorded data surprisingly well. The deviation between the firing regimen of the model and the in vivo data are on the same level as deviations among monkeys and sessions. This suggests that, despite strong simplifications and abstractions of cortical network models, they are nevertheless capable of generating realistic spiking activity. To reach a realistic firing state, it was not only necessary to include both N-methyl-d-aspartate and GABA(B) synaptic conductances in our model, but also to markedly increase the strength of excitatory synapses onto inhibitory neurons (>2-fold) in comparison to literature values, hinting at the importance to carefully adjust the effect of inhibition for achieving realistic dynamics in current network models.
- Published
- 2011
- Full Text
- View/download PDF
31. Bet v 1-specific T-cell receptor/forkhead box protein 3 transgenic T cells suppress Bet v 1-specific T-cell effector function in an activation-dependent manner.
- Author
-
Schmetterer KG, Haiderer D, Leb-Reichl VM, Neunkirchner A, Jahn-Schmid B, Küng HJ, Schuch K, Steinberger P, Bohle B, and Pickl WF
- Subjects
- Allergens genetics, Allergens immunology, Antigens, Plant immunology, Betula, Cell Separation, Flow Cytometry, Forkhead Transcription Factors immunology, Genetic Vectors, HEK293 Cells, Humans, Lymphocyte Activation immunology, Pollen, Receptors, Antigen, T-Cell, alpha-beta immunology, Retroviridae, T-Lymphocytes, Regulatory metabolism, Transduction, Genetic, Transfection, Transgenes, Antigens, Plant genetics, Forkhead Transcription Factors genetics, Genetic Engineering methods, Receptors, Antigen, T-Cell, alpha-beta genetics, T-Lymphocytes, Regulatory immunology
- Abstract
Background: Regulatory T (Treg) cells establish and maintain tolerance to self-antigens and many foreign antigens, such as allergens, by suppressing effector T-cell proliferation and function. We have previously shown that human T-cell receptor (TCR) αβ-chains specific for allergen-derived epitopes confer allergen specificity on peripheral blood T cells of individuals with and without allergy., Objective: To study the feasibility of generating allergen-specific human Treg cells by retroviral transduction of a transcription unit encoding forkhead box protein 3 (FOXP3) and allergen-specific TCR αβ-chains., Methods: cDNAs encoding the α and β-chains of a Bet v 1(142-153)-specific TCR (TCR alpha variable region 6/TCR beta variable region 20) and human FOXP3 were linked via picornaviral 2A sequences and expressed as single translational unit from an internal ribosomal entry site-green fluorescence protein-containing retroviral vector. Retrovirally transduced peripheral blood T cells were tested for expression of transgenes, Treg phenotype, and regulatory capacity toward allergen-specific effector T cells., Results: Transduced T cells displayed a Treg phenotype with clear-cut upregulation of CD25, CD39, and cytotoxic T-lymphocyte antigen 4. The transduced cells were hyporesponsive in cytokine production and secretion and, like naturally occurring Treg cells, did not proliferate after antigen-specific or antigen-mimetic stimulation. However, proliferation was inducible upon exposure to exogenous IL-2. In coculture experiments, TRAV6(+)TRBV20(+)FOXP3(+) transgenic T cells, unlike FOXP3(+) single transgenic T cells or naturally occurring Treg cells, highly significantly suppressed T cell cytokine production and proliferation of corresponding allergen-specific effector T cells in an allergen-specific, dose-dependent manner., Conclusion: We demonstrate a transgenic approach to engineer human allergen-specific Treg cells that exert their regulatory function in an activation-dependent manner. Customized Treg cells might become useful for tolerance induction therapies in individuals with allergic and other immune-mediated diseases., (Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
32. Compensating Inhomogeneities of Neuromorphic VLSI Devices Via Short-Term Synaptic Plasticity.
- Author
-
Bill J, Schuch K, Brüderle D, Schemmel J, Maass W, and Meier K
- Abstract
Recent developments in neuromorphic hardware engineering make mixed-signal VLSI neural network models promising candidates for neuroscientific research tools and massively parallel computing devices, especially for tasks which exhaust the computing power of software simulations. Still, like all analog hardware systems, neuromorphic models suffer from a constricted configurability and production-related fluctuations of device characteristics. Since also future systems, involving ever-smaller structures, will inevitably exhibit such inhomogeneities on the unit level, self-regulation properties become a crucial requirement for their successful operation. By applying a cortically inspired self-adjusting network architecture, we show that the activity of generic spiking neural networks emulated on a neuromorphic hardware system can be kept within a biologically realistic firing regime and gain a remarkable robustness against transistor-level variations. As a first approach of this kind in engineering practice, the short-term synaptic depression and facilitation mechanisms implemented within an analog VLSI model of I&F neurons are functionally utilized for the purpose of network level stabilization. We present experimental data acquired both from the hardware model and from comparative software simulations which prove the applicability of the employed paradigm to neuromorphic VLSI devices.
- Published
- 2010
- Full Text
- View/download PDF
33. H1-receptor antagonists terfenadine and loratadine inhibit spontaneous growth of neoplastic mast cells.
- Author
-
Hadzijusufovic E, Peter B, Gleixner KV, Schuch K, Pickl WF, Thaiwong T, Yuzbasiyan-Gurkan V, Mirkina I, Willmann M, and Valent P
- Subjects
- Animals, Apoptosis drug effects, Blotting, Western, Caspase 3 metabolism, Cats, Cell Line, Tumor, Dasatinib, Dogs, Dose-Response Relationship, Drug, Drug Synergism, Flow Cytometry, Humans, Inhibitory Concentration 50, Mastocytoma drug therapy, Mastocytoma metabolism, Mastocytoma pathology, Mastocytosis, Systemic drug therapy, Mastocytosis, Systemic metabolism, Mastocytosis, Systemic pathology, Proto-Oncogene Proteins c-kit metabolism, Pyrimidines pharmacology, Staurosporine analogs & derivatives, Staurosporine pharmacology, Thiazoles pharmacology, Tumor Cells, Cultured, Cell Proliferation drug effects, Histamine H1 Antagonists, Non-Sedating pharmacology, Loratadine pharmacology, Terfenadine pharmacology
- Abstract
Objective: In mast cell (MC) neoplasms, clinical problems requiring therapy include local aggressive and sometimes devastating growth of MCs and mediator-related symptoms. A key mediator of MCs responsible for clinical symptoms is histamine. Therefore, use of histamine receptor (HR) antagonists is an established approach to block histamine effects in these patients., Materials and Methods: We screened for additional beneficial effects of HR antagonists and asked whether any of these agents would also exert growth-inhibitory effects on primary neoplastic MCs, the human MC line HMC-1, and on two canine MC lines, C2 and NI-1., Results: We found that the HR1 antagonists terfenadine and loratadine suppress spontaneous growth of HMC-1, C2, and NI-1 cells, as well as growth of primary neoplastic MCs in all donors tested (human patients, n = 5; canine patients, n = 8). The effects of both drugs were found to be dose-dependent (IC(50): terfenadine, 1-20 μM; loratadine, 10-50 μM). Both agents also produced apoptosis in neoplastic MCs and augmented apoptosis-inducing effects of two KIT-targeting drugs, PKC412 and dasatinib. The other HR1 antagonists (fexofenadine, diphenhydramine) and HR2 antagonists (famotidine, cimetidine, ranitidine) tested did not exert substantial growth-inhibitory effects on neoplastic MCs. None of the histamine receptor blockers were found to modulate cell-cycle progression in neoplastic MCs., Conclusions: The HR1 antagonists terfenadine and loratadine, in addition to their antimediator activity, exert in vitro growth-inhibitory effects on neoplastic MCs. Whether these drugs (terfenadine) alone, or in combination with KIT inhibitors, can also affect in vivo neoplastic MC growth remains to be determined., (Copyright © 2010 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
34. In vitro and in vivo growth-inhibitory effects of cladribine on neoplastic mast cells exhibiting the imatinib-resistant KIT mutation D816V.
- Author
-
Böhm A, Sonneck K, Gleixner KV, Schuch K, Pickl WF, Blatt K, Peter B, Herrmann H, Schernthaner GH, Pehamberger H, Rabitsch W, Sperr WR, and Valent P
- Subjects
- Adult, Aged, Amino Acid Substitution, Apoptosis drug effects, Apoptosis genetics, Benzamides, Caspases metabolism, Cell Line, Tumor, Drug Resistance, Neoplasm genetics, Female, Gene Expression Regulation, Neoplastic drug effects, Gene Expression Regulation, Neoplastic genetics, Humans, Imatinib Mesylate, Male, Mast Cells pathology, Mastocytosis, Systemic genetics, Mastocytosis, Systemic pathology, Middle Aged, Proto-Oncogene Proteins c-kit genetics, Tryptases blood, Antineoplastic Agents administration & dosage, Cladribine administration & dosage, Drug Resistance, Neoplasm drug effects, Mast Cells enzymology, Mastocytosis, Systemic drug therapy, Mastocytosis, Systemic enzymology, Mutation, Missense, Piperazines pharmacology, Proto-Oncogene Proteins c-kit metabolism, Pyrimidines pharmacology
- Abstract
Objective: In most patients with systemic mastocytosis (SM), including aggressive SM (ASM) and mast cell (MC) leukemia (MCL), neoplastic cells express the oncogenic KIT mutation D816V, which confers resistance to imatinib. Cladribine (2CdA) is a nucleoside analog that has been introduced as a promising agent for treatment of advanced SM., Materials and Methods: We examined the in vitro effects of 2CdA on growth of neoplastic MC, and the in vivo effects of 2CdA (0.13 mg/kg/day intravenously, days 1-5; three to eight cycles) in seven patients with advanced SM., Results: Cladribine was found to inhibit growth of primary MC and the MC line HMC-1 in a dose-dependent manner, with lower IC(50) values recorded in HMC-1.2 cells harboring KIT D816V (IC(50): 10 ng/mL) compared to HMC-1.1 cells lacking KIT D816V (IC(50): 300 ng/mL). In two patients with progressive smoldering SM, 2CdA produced a long-lasting response with a sustained decrease in serum tryptase levels, whereas in patients with progressive ASM or MCL, 2CdA showed little if any effects. The drug was well-tolerated in most cases. However, one patient developed a massive generalized purulent long-lasting skin rash. The antiproliferative effects of 2CdA on MC were found to be associated with morphologic signs of apoptosis and caspase cleavage. Cladribine did not counteract the kinase activity of KIT D816V or KIT-downstream signaling molecules., Conclusions: Cladribine may be a promising agent for treatment of progressive smoldering KIT D816V(+) SM. In rapidly progressing ASM or MCL, additional or alternative drugs are required to induce long-lasting antineoplastic effects.
- Published
- 2010
- Full Text
- View/download PDF
35. [Not Available].
- Author
-
Pecevski D, Natschläger T, and Schuch K
- Abstract
The Parallel Circuit SIMulator (PCSIM) is a software package for simulation of neural circuits. It is primarily designed for distributed simulation of large scale networks of spiking point neurons. Although its computational core is written in C++, PCSIM's primary interface is implemented in the Python programming language, which is a powerful programming environment and allows the user to easily integrate the neural circuit simulator with data analysis and visualization tools to manage the full neural modeling life cycle. The main focus of this paper is to describe PCSIM's full integration into Python and the benefits thereof. In particular we will investigate how the automatically generated bidirectional interface and PCSIM's object-oriented modular framework enable the user to adopt a hybrid modeling approach: using and extending PCSIM's functionality either employing pure Python or C++ and thus combining the advantages of both worlds. Furthermore, we describe several supplementary PCSIM packages written in pure Python and tailored towards setting up and analyzing neural simulations.
- Published
- 2009
- Full Text
- View/download PDF
36. Motif distribution, dynamical properties, and computational performance of two data-based cortical microcircuit templates.
- Author
-
Haeusler S, Schuch K, and Maass W
- Subjects
- Animals, Humans, Neural Networks, Computer, Computer Simulation, Models, Neurological, Neocortex physiology, Nerve Net physiology, Nonlinear Dynamics
- Abstract
The neocortex is a continuous sheet composed of rather stereotypical local microcircuits that consist of neurons on several laminae with characteristic synaptic connectivity patterns. An understanding of the structure and computational function of these cortical microcircuits may hold the key for understanding the enormous computational power of the neocortex. Two templates for the structure of laminar cortical microcircuits have recently been published by Thomson et al. and Binzegger et al., both resulting from long-lasting experimental studies (but based on different methods). We analyze and compare in this article the structure of these two microcircuit templates. In particular, we examine the distribution of network motifs, i.e. of subcircuits consisting of a small number of neurons. The distribution of these building blocks has recently emerged as a method for characterizing similarities and differences among complex networks. We show that the two microcircuit templates have quite different distributions of network motifs, although they both have a characteristic small-world property. In order to understand the dynamical and computational properties of these two microcircuit templates, we have generated computer models of them, consisting of Hodgkin-Huxley point neurons with conductance based synapses that have a biologically realistic short-term plasticity. The performance of these two cortical microcircuit models was studied for seven generic computational tasks that require accumulation and merging of information contained in two afferent spike inputs. Although the two models exhibit a different performance for some of these tasks, their average computational performance is very similar. When we changed the connectivity structure of these two microcircuit models in order to see which aspects of it are essential for computational performance, we found that the distribution of degrees of nodes is a common key factor for their computational performance. We also show that their computational performance is correlated with specific statistical properties of the circuit dynamics that is induced by a particular distribution of degrees of nodes.
- Published
- 2009
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.