La maladie d’Alzheimer (MA) est une pathologie neurodégénérative communément caractérisée par une perte progressive de la mémoire. L’étiologie de la MA demeure incertaine à ce jour ce qui complique l’élaboration de stratégies thérapeutiques permettant de l’éradiquer. L’accumulation des échecs thérapeutiques pourrait en partie s’expliquer par le fait que l’hypothèse amyloïde, qui met en avant l’implication prépondérante du peptide bêta-amyloïde (Aβ) dans la physiopathologie de la MA, serait incomplète. En utilisant un modèle murin transgénique de la MA, la souris TgCRND8, j’ai pu compléter l’hypothèse amyloïde en proposant l’implication, en plus de l’Aβ, du fragment carboxy-terminal bêta (β-CTF). Ces deux métabolites amyloïdogéniques de l’APP seraient responsables de l’altération de formes différentes de mémoire. Le dosage de ces métabolites dans l’hippocampe, suite au traitement chronique des souris avec un inhibiteur de β ou de γ-secrétase, a mis en évidence que le β-CTF serait responsable de l’atteinte de la mémoire impliquée dans la détection du remplacement d’un objet, alors que l’Aβ perturberait la mémoire permettant la détection du déplacement d’un objet. Ces travaux suggèrent qu’il serait judicieux de développer de nouvelles stratégies thérapeutiques qui diminuent à la fois les niveaux cérébraux des deux fragments amyloïdogéniques, le β-CTF et l’Aβ. / Alzheimer’s disease (AD) is a neurodegenerative pathology commonly characterized by a progressive memory loss. To these days, AD’s etiology has remained unclear which complicates the development of therapeutic strategies enabling to eradicate the pathology. The accumulation of therapeutic failures could partly be explained by the fact that the amyloid hypothesis, which highlights the leading involvement of the amyloid beta peptide (Aβ) in the physiopathology of AD, could be incomplete. Using a transgenic mouse model of AD, the TgCRND8 mice strain, I expanded the amyloid hypothesis, suggesting the involvement of the beta carboxy-terminal fragment (β-CTF), in addition to Aβ. These two amyloidogenic metabolites could be responsible for the alteration of different forms of memory. The dosage of these metabolites, after mice chronic treatment with either a β- or a γ-secretase inhibitor, highlighted the fact that β-CTF could be responsible for the deterioration of the memory involved in the detection of the replacement of an object. As for Aβ, it could disrupt the memory allowing the detection of the displacement of an object. This work suggests that it would be judicious to develop therapeutic strategies reducing brain levels of both amyloid fragments, β-CTF and Aβ.

Nonsteroidal anti-inflammatory substances became a very frequently used and constantly evolved group of the drugs, particularly in a human medicine. The risk of their penetration into the environment, especially to the water environment, is rising during the recent years. The diploma thesis is focused on a selection of appropriate separation method and optimization of analytical procedure for the identification and determination of the non-steroidal anti-inflammatory drugs in sewage and surface waters. Salicylic acid, ketoprofen, diclofenac and ibuprofen were chosen from the wide range of NSAIDs as the most widespread agents of this drugs group in the medical practice. The method was optimized and elaborated using the model water samples. This method was used for determination of the analytes contained in the real water samples. Waste water samples were taken from the large-scale wastewater treatment plant in Brno-Modřice and surface water samples were taken from the Highlands river Křetínka. Solid phase extraction (SPE) was used for the real samples treatment and preconcentration, the determination was performed using the high performance liquid chromatography with mass spectroscopy method (LC-MS).

This work is based on the current issue of increasing concentrations of pharmaceutical residues in various components of the environment. These new environmental contaminants continuously enter the environment. The most affected environmental component is the aquatic environment. This study is focused on the development and optimization of reliable analytical method, which can determine selected drugs in the aquatic environment (waste waters and surface waters) qualitatively and quantitatively. The target compounds were selected mainly from the group of non-steroidal anti-inflammatory drugs (NSAID): salicylic acid, acetylsalicylic acid, clofibric acid, ibuprofen, acetaminophen, caffeine, naproxen, mefenamic acid, ketoprofen and diclofenac. NSAIDs are one of the most used drugs in Czech Republic. For the final analysis of this study was used the comprehensive two-dimensional gas chromatography with mass spectrometric detection Time-of-Flight (GCxGC-TOF MS). It is a very sensitive and reliable analytical method for trace and ultra-trace analysis. Simultaneously, solid phase extraction (SPE) and derivatization are optimized in this work. Optimized analytical method including SPE, derivatization with MSTFA (N-methyl-N-(trimethylsilyl) trifluoroacetamide) and final analysis by GCxGC-TOF MS were applied successfully for the analysis of real samples. Samples of waste water were collected from the waste water treatment plant in Brno – Modřice and samples of surface water were collected from two river streams Svratka and Svitava in Moravian region. The range of concentrations of selected drug residues varied from one to tens of g/L in wastewater and from tens to hundreds of ng/L in surface waters. The degree of wastewater and surface waters contamination by drug residues is assessed in conclusions of the work. Simultaneously, spontaneous degradation of selected drugs in water and removal efficiency of the wastewater treatment plant is assessed in conclusions of the work. The developed method is usable for monitoring and environmental analysis of water ecosystems. It is usable not only for selected drugs, but even for other organic compounds with similar properties.

Modifying the metabolism of the body’s own endocannabinoids is a novel approach for analgesia. Two key catabolic enzymes are fatty acid amide hydrolase (FAAH) and inflammation-inducible cyclooxygenase 2 (COX-2). The cellular uptake of the key endocannabinoid anandamide (AEA) has been found to be regulated by its FAAH-catalysed intracellular degradation, but COX-2 has not been investigated in this respect. We aimed to find out whether or not COX-2 in an in vitro inflammation setting would be able to gate AEA uptake. To achieve this, C6 cells and Raw 264.7 cells were stimulated with LPS/INF-γ and lysates then analyzed by immunoblot in order to verify COX-2 expression. AEA cellular uptake was quantified using a radioassay with [3H]-AEA. It was found that COX-2 was not inducible in C6 cells using the LPS/INF-γ conditions studied, while it was inducible in Raw 264.7 cells. AEA uptake in the COX-2-induced Raw 264.7 cells was not reduced by inhibitors of this enzyme. FAAH appeared to be down-regulated in the stimulated Raw 264.7 cells, and this was reflected in an overall lower AEA uptake. Our interpretation of the data points to FAAH as gating AEA uptake. Additional experiments are required to validate our findings by verifying significance.