Auf die Stärken kommt es an? Spannungsverhältnisse im Spiegel der Pädagogik mit Menschen im Autismus-Spektrum

Die Frage nach der (Nicht-)Teilhabe von Menschen im Autismus-Spektrum an den gesellschaftlichen Lebensbereichen nimmt eine zentrale Rolle in den fachlichen Debatten um Neurodiversität sowie den Beiträgen autistischer Menschen aus eigener Perspektive hierzu ein. Gefordert wird die Überwindung defizitorientierter, pathologisierender Deutungsmuster von Autismus zugunsten einer Stärken-Perspektive. Im Kontext der Pädagogik stellt der Diskurs um die Defizit- vs. Stärkenorientierung allgemein keine Neuerung dar – ebenso wenig wie die Hinwendung zu stärkenorientierten Ansätzen. Dennoch zeigt die (2) Stärken-Perspektive in der Pädagogik mit Menschen im Autismus-Spektrum Besonderheiten auf, die es nachfolgend hinsichtlich ihrer (3) Spannungen und Widersprüche zu diskutieren gilt. Mit der (4) rehistorisierenden Betrachtung wird abschließend auf einen theoretischen Ansatz verwiesen, dessen Fokus nicht auf der Zuschreibung von Fähigkeitseigenschaften (‚Defiziten‘ oder ‚Stärken‘), sondern auf der Rekonstruktion von Sinn- und Bedeutungszusammenhängen von autistischen Verhaltensweisen liegt. (DIPF/Orig.

Entwicklung eines Patientenmoduls für eine internationale medizinische Datenbank

Seit ihrer Gründung im Jahr 2006 forscht die Tinnitus Research Initiative über Tinnitus. Betroffene hören Geräusche oder Töne, ohne dass eine externe Quelle existiert. Um Tinnitus besser verstehen und behandeln zu können, wurde die Tinnitus- Database entwickelt. Diese sammelt Daten von Patienten mit Tinnitus und nutzt diese Daten in der Forschung. Dabei müssen Patienten Fragebögen ausfüllen, die Auskunft über die Art des Tinnitus geben können. Bisher müssen aber Patienten und Ärzte diese Fragebögen gemeinsam ausfüllen. Ziel dieser Arbeit ist es, ein Patientenmodul zu entwickeln, mit dessen Hilfe Patienten Fragebögen selbstständig ausfüllen können. Dabei wurden verschiedene Komponenten entwickelt, die von verschiedenen Nutzern, meist Ärzte und Patienten, genutzt werden. In dieser Arbeit werden die Anforderungen, der Entwurf und die Implementation einiger Aspekte der Entwicklung des Patientenmoduls behandelt

Role of glutathione S-transferases and the mercapturic acid pathway in the biotransformation potential of two zebrafish (Danio rerio) test systems: early life stages and PAC2 cells

Zebrafish (Danio rerio) early life stages provide an important model for chemical risk assessment due to their genetic similarity to humans and the availability of well-established high-throughput techniques. Cells isolated from zebrafish conserve all these advantages and can, in addition, be multiplied in the laboratory to an unlimited extend. However, the biotransformation capacities of both systems have not been fully charac-terized. One biotransformation pathway, which is of utmost importance for the clearance of electrophilic compounds and phase I biotransformation products, is the mercapturic acid pathway. Its first step is the conjugation of the electrophile with glutathione, catalyzed by glutathione S-transferases (GSTs). The gluta-thione conjugates are usually further biotransformed within the mercapturic acid pathway by sequential re-moval of the glutamyl- and glycyl-moieties and an acetylation step followed by elimination of the mercap-turate. Considering the significance of this biotransformation route for the outcome of toxicological investi-gations, this thesis aims to close some major knowledge gaps regarding the protein expression of GSTs and the functionality of the mercapturic acid pathway in two test systems, zebrafish early life stages and the embryo-derived cell line PAC2. To investigate the repertoire of cytosolic GSTs and their expression dynamics, a targeted proteomics meth-od using electrospray ionization (ESI) was developed. Zebrafish embryos showed a basal expression of GST isoenzymes belonging to the classes alpha, mu, pi and rho as early as 4 hours post fertilization, indi-cating maternal transfer. After hatching, all cytosolic GST classes could be detected in the free-swimming larvae. The embryo-derived cell line PAC2 also expressed all cytosolic GST classes, except class alpha. Motivated by the abundant expression of GSTs in the zebrafish models, focus was set on the potential of GSTs to biotransform a model substrate (1-chloro-2,4-dinitrobenzene, CDNB) and to initiate its further bio-transformation within the mercapturic acid pathway. Since CDNB has no acid/base properties, an atmos-pheric pressure chemical ionization (APCI) method based on electron capture was developed for CDNB analysis at and below the nontoxic concentrations. For the determination of CDNB biotransformation prod-ucts of the mercapturic acid pathway, an ESI method was developed. In both test systems, the expression of cytosolic GSTs was not affected by non-toxic concentrations of the model substrate CDNB. Further-more, both test systems disclosed a fully functional mercapturic acid pathway with the first (glutathione conjugate) and last (mercapturate) biotransformation product being produced and excreted in zebrafish early life stages and PAC2 cells. To conclude, this thesis reveals the expression of a large GST repertoire and a functional mercapturic acid pathway in zebrafish early life stages and PAC2 cells. The presence of this important chemical activa-tion/deactivation and clearance route supports the application of these test systems as alternative models in toxicology and chemical hazard assessment

LC-APCI(-)-MS Determination of 1-Chloro-2,4-dinitrobenzene, a Model Substrate for Glutathione S-Transferases

1-Chloro-2,4-dinitrobenzene (CDNB) is widely used as a model substrate for measuring the enzyme activity of glutathione S-transferases in toxicity studies and in studies focusing on the metabolic capacity of different test systems. To allow the quantification of CDNB at low, nontoxic concentrations, we developed a sensitive liquid chromatography mass spectrometry (LC-MS) technique, which is based on electron capture ionization using atmospheric pressure chemical ionization (APCI) in negative ion mode. Gas-phase reactions occurring under atmospheric pressure produce specific ions that allow direct CDNB quantification down to 17 ng/mL in water. Using the new technique, we were able to verify CDNB exposure concentrations applied in two typical toxicity studies with early life stages of the common model organisms, zebrafish (Danio rerio) and a zebrafish embryonic cell line (PAC2)

Glutathione S-Transferase Protein Expression in Different Life Stages of Zebrafish (Danio rerio)

Zebrafish is a widely used animal model in biomedical sciences and toxicology. Although evidence for the presence of phases I and II xenobiotic defense mechanisms in zebrafish exists on the transcriptional and enzyme activity level, little is known about the protein expression of xenobiotic metabolizing enzymes. Given the important role of glutathione S-transferases (GSTs) in phase II biotransformation, we analyzed cytosolic GST proteins in zebrafish early life stages and different organs of adult male and female fish, using a targeted proteomics approach. The established multiple reaction monitoring-based assays enable the measurement of the relative abundance of specific GST isoenzymes and GST classes in zebrafish through a combination of proteotypic peptides and peptides shared within the same class. GSTs of the classes alpha, mu, pi and rho are expressed in zebrafish embryo as early as 4 h postfertilization (hpf). The majority of GST enzymes are present at 72 hpf followed by a continuous increase in expression thereafter. In adult zebrafish, GST expression is organ dependent, with most of the GST classes showing the highest expression in the liver. The expression of a wide range of cytosolic GST isoenzymes and classes in zebrafish early life stages and adulthood supports the use of zebrafish as a model organism in chemical-related investigations

Data from: Glutathione S-transferase protein expression in different life stages of zebrafish (Danio rerio)

Zebrafish is a widely used animal model in biomedical sciences and toxicology. Although evidence for the presence of phase I and phase II xenobiotic defense mechanisms in zebrafish exists on the transcriptional and enzyme activity level, little is known about the protein expression of xenobiotic metabolizing enzymes. Given the important role of glutathione S-transferases (GSTs) in phase II biotransformation, we analyzed cytosolic GST proteins in zebrafish early life stages and different organs of adult male and female fish, using a targeted proteomics approach. The established Multiple Reaction Monitoring-based assays enable the measurement of the relative abundance of specific GST isoenzymes and GST classes in zebrafish through a combination of proteotypic peptides and peptides shared within the same class. GSTs of the classes alpha, mu, pi and rho are expressed in zebrafish embryo as early as 4 hours post fertilization (hpf). The majority of GST enzymes are present at 72 hpf followed by a continuous increase in expression thereafter. In adult zebrafish, GST expression is organ dependent, with most of the GST classes showing the highest expression in the liver. The expression of a wide range of cytosolic GST isoenzymes and classes in zebrafish early life stages and adulthood supports the use of zebrafish as a model organism in chemical-related investigations

Biotransformation Capacity of Zebrafish (Danio rerio) Early Life Stages: Functionality of the Mercapturic Acid Pathway

Zebrafish (Danio rerio) early life stages offer a versatile model system to study the efficacy and safety of drugs or other chemicals with regard to human and environmental health. This is because, aside from the well-characterized genome of zebrafish and the availability of a broad range of experimental and computational research tools, they are exceptionally well suited for high-throughput approaches. Yet, one important pharmacokinetic aspect is thus far only poorly understood in zebrafish embryo and early larvae: their biotransformation capacity. Especially, biotransformation of electrophilic compounds is a critical pathway because they easily react with nucleophile molecules, such as DNA or proteins, potentially inducing adverse health effects. To combat such adverse effects, conjugation reactions with glutathione and further processing within the mercapturic acid pathway have evolved. We here explore the functionality of this pathway in zebrafish early life stages using a reference substrate (1-chloro-2,4-dinitrobenzene, CDNB). With this work, we show that zebrafish embryos can biotransform CDNB to the respective glutathione conjugate as early as 4h postfertilization. At all examined life stages, the glutathione conjugate is further biotransformed to the last metabolite of the mercapturic acid pathway, the mercapturate, which is slowly excreted. Being able to biotransform electrophiles within the mercapturic acid pathway shows that zebrafish early life stages possess the potential to process xenobiotic compounds through glutathione conjugation and the formation of mercapturates. The presence of this chemical biotransformation and clearance route in zebrafish early life stages supports the application of this model in toxicology and chemical hazard assessment

Characterization of the Mercapturic Acid Pathway, an Important Phase II Biotransformation Route, in a Zebrafish Embryo Cell Line

In view of the steadily increasing number of chemical compounds used in various products and applications, high-throughput toxicity screening techniques can help meeting the needs of 21st century risk assessment. Zebrafish (Danio rerio), especially its early life stages, are increasingly used in such screening efforts. In contrast, cell lines derived from this model organism have received less attention so far. A conceivable reason is the limited knowledge about their overall capacity to biotransform chemicals and the spectrum of expressed biotransformation pathways. One important biotransformation route is the mercapturic acid pathway, which protects organisms from harmful electrophilic compounds. The fully functional pathway involves a succession of several enzymatic reactions. To investigate the mercapturic acid pathway performance in the zebrafish embryonic cell line, PAC2, we analyzed the biotransformation products of the reactions comprising this pathway in the cells exposed to a nontoxic concentration of the reference substrate, 1-chloro-2,4-dinitrobenzene (CDNB). Additionally, we used targeted proteomics to measure the expression of cytosolic glutathione S-transferases (GSTs), the enzyme family catalyzing the first reaction in this pathway. Our results reveal that the PAC2 cell line expresses a fully functional mercapturic acid pathway. All but one of the intermediate CDNB biotransformation products were identified. The presence of the active mercapturic acid pathway in this cell line was further supported by the expression of a large palette of GST enzyme classes. Although the enzymes of the class alpha, one of the dominant GST classes in the zebrafish embryo, were not detected, this did not seem to affect the capacity of the PAC2 cells to biotransform CDNB. Our data provide an important contribution toward using zebrafish cell lines, specifically PAC2, for animal-free high-throughput screening in toxicology and chemical hazard assessment