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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

IRINOTECANTOXICITY RELATED TO GILBERT´S SYNDROME   - COMPARISON OF THREE METHODS FOR GENOTYPING OF UGT1A1 (TA)n

Fredriksson, Lena January 2009 (has links)
Gilbert’s syndrome (GS) occurs in approximately 10% of the European population. The most common cause is homozygosity for UGT1A1*28, which is a TA repeat expansion in the promoter of UGT1A1. It is characterised by intermittent hyperbilirubinemia due to reduced hepatic activity of the  enzyme UDP-glucuronosyl-transferase 1A1(UGT1A1). GS also  alteres the pharmacokinetics of some drugs and increases the risk of drug toxicity. Irinotecan (Camptosar®, Campto®) is used in metastatic colorectal cancer and the active metabolite is inactivated by UGT1A1. Studies have shown that GS can be a risk factor for toxicity during irinotecan therapy. Three different methods for genotyping of UGT1A1*28 have been tested. PCR with electrophoresis used for size separation, melting temperature analysis and fluorescent PCR followed by fragment analysis on a capillary sequencer. The last method was found to be superior. This method was used for genotyping of patients with colorectal cancer treated with irinotecan and 5-fluorouracil in the Nordic VI study. A significant association between UGT1A1 genotype and plasma bilirubin level before the start of irinotecan treatment was seen (ANOVA p<0.0001). Patients with GS had an overall increased risk of adverse drug reactions (Fishers Exact test p=0.02). Gilbert’s syndrome can be diagnosed by genotyping UGT1A1*28 with a fragment analysis method. Genotyping of UGT1A1*28 can be used to identify patients with an increased risk of adverse reactions to irinotecan. / Gilberts syndrom (GS) drabbar upp till 10% av befolkningen i Västeuropa. GS beror på nedsatt aktivitet av enzymet UDP-glukuronosyltransferas 1A1 (UGT1A1) i levern. Den vanligaste orsaken är att individen är homozygot för en insertion av två baser i promotorn för genen UGT1A1. Denna genvariant kallas (TA)7TAA  eller UGT1A1*28. GS leder till intermittent stegring av bilirubin vid infektioner, men bilirubinstegring kan förekomma även utan utlösande agens. GS kan också leda till bilirubinstegring vid viss läkemedelsbehandling. Irinotekan (Campto®) används vid metastaserande colorektal cancer och dess aktiva metabolit inaktiveras av UGT1A1. Det finns rapporter om att GS ger ökad risk för toxiska biverkningar av irinotekan. Tre metoder för att bestämma UGT1A1 har jämförts: PCR med elfores, PCR med smältpunktsanalys och PCR med fragmentanalys på sekvensator. Den sista metoden var bäst och användes för att genotypa UGT1A1 hos patienter med colorektal cancer från Nordic VI-studien. De behandlades med irinotekan i kombination med bolusinjektion eller infusion av 5-fluorouracil. Vi fann att  patienter med GS hade signifikant högre S-bilirubin före behandling jämfört med övriga patienter. De hade även ökad frekvens biverkningar av irinotekan (Fishers exakta test p=0,02). Genotypning av UGT1A1 kan således användas för att diagnostisera Gilberts syndrom hos patienter med oförklarad bilirubinstegring. Det kan även användas för att identifiera patienter med ökad risk för biverkningar av irinotekan.
52

Hälsorisker med Bisfenol A / Health risks of Bisphenol-A

Elm, Niklas January 2012 (has links)
Bisfenol A (BPA) är ett propanderivat med två fenolgrupper. Det syntetiserades för första gången år 1905 av Thomas Zincke vid Marburgs universitet. När en polymerkemist upptäckte att det kunde användas för att bilda polykarbonatplaster växte dess popularitet. Idag är BPA-industrin en miljardindustri och många av oss använder dagligen plaster där denna kemikalie ingår. Nu har det gjorts nya toxikologiska undersökningar som visar att BPA kanske inte är så ofarligt som man tidigare trott. Vårt största intag av föreningen sker via mag-tarmkanalen genom att det kan läcka från olika slags plastföremål i kontakt med livsmedel. Enligt en panel sammansatt av USA:s National Institutes of Health finns det en risk för negativa effekter på hjärna och beteende hos barn. Reaktionerna på riskbedömningarna har varierat och detta examensarbete vill presentera några argument för vikten av att undersöka BPA: s hälsorisker mer. Syftet med detta examensarbete är att med en litteraturstudie undersöka en del av vad som finns dokumenterat om BPA: s hälsorisker för människan, typ av genomförda toxikologiska undersökningar och hur dessa resultat har påverkat företag och länder. Denna litteraturstudie visar att det finns stor bredd på tolkningen av de toxikologiska studiernas resultat och därmed är det osäkert om det finns hälsorisker eller inte. Det finns omdebatterade resultat som tyder på en ökad risk av toxikologiska effekter, till exempel skada på hjärta hos barn men det finns ingen fastställd hälsorisk för människor. Mer standardisering behövs i forskningen för att ge den en högre kvalitet och göra studier mer jämförbara. / Bisphenol-A (BPA) is a propane derivative with two phenol groups. It was synthetisized for the first time in the year of 1905 by Thomas Zincke at the Marburg University. When a polymer chemist discovered that it could be used to form polycarbonate plastics its popularity grew. Today the chemistry of BPA is a billion industry and many of us use daily plastics in which this chemical is used for. Many new toxicological studies have shown that BPA maybe is not as friendly as before thought. Our biggest exposure to it is orally because it can leak from different plastics with contact to food. According to a panel assembled by USA’s National Institutes of Health there is a risk of negative effects on brain and behaviour on children. The reactions of the risk assessment have been different and this thesis wants to show some arguments for the importance of exploring the health risks of BPA more. The purpose of this thesis is to use a literature study to investigate a part of what is documented about the health effects of BPA on humans, the kind of toxicological studies performed and how their results have affected companies and countries. The literature study shows that the width of interpretation of the toxicological studies’ results is big and thus that it is uncertain if there are health effects or not. There are some uncertain results facts funded on conflict that show a heightened risk for toxicological effects, for example damage on heart and changes in behavior in infants but there is no empirically stated health risk in humans. More standardization in research is needed for giving it a higher quality and thus making it more comparable.
53

Neuropeptide Receptors as Treatment Targets in Alcohol Use Disorders

Aziz, Abdul Maruf Asif January 2017 (has links)
Alcohol use disorder (AUD) is a complex disorder with multiple pathophysiological processes contributing to the initiation, progression and development of the disease state. AUD is a chronic relapsing disease with escalation of alcohol-intake over time in repeated cycles of tolerance, abstinence and relapse and hence, it is very difficult to treat. There are only a few currently available treatments with narrow efficacy and variable patient response. Thus it is important to find new, more effective medications to increase the number of patients who can benefit from pharmacological treatment of AUD. The research presented in this thesis work focuses on the critical involvement of central neuropeptides in alcohol-related behaviors. The overall aim was to evaluate the nociceptin/orphanin FQ (NOP) receptor, the neuropeptide Y (NPY) Y2 receptor and the melanin-concentrating hormone (MCH) receptor 1 as novel and potential pharmacological treatment targets for AUD by testing the NOP receptor agonist SR-8993, the NPY-Y2 receptor antagonist CYM-9840 and the MCH1 receptor antagonist GW803430 in established animal models. In the first study (Paper I), the novel and selective NOP agonist SR-8993 was assessed in rat models of motivation to obtain alcohol and relapse to alcohol seeking behavior using the operant self-administration (SA) paradigm. Firstly, treatment with SR-8993 (1 mg/kg) showed a mildly anxiolytic effect and reversed acute alcohol withdrawal-induced “hangover” anxiety in the elevated plus-maze (EPM). Next, it potently attenuated alcohol SA and motivation to obtain alcohol in the progressive ratio responding (PRR) and reduced both alcohol cue-induced and yohimbine stress-induced reinstatement of alcohol seeking, without affecting the pharmacology and metabolism of alcohol nor other control behaviors. To extend these findings, SR-8993 was evaluated in escalated alcohol-intake in rats.  Treatment with SR-8993 significantly suppressed alcohol-intake and preference in rats that were trained to consume high amounts of alcohol in the two-bottle free choice intermittent access (IA) paradigm. SR-8993 also blocked operant SA of alcohol in rats that showed robust escalation in operant alcohol SA following chronic IA exposure to alcohol. In the second study (Paper II), SR-8993 was further evaluated in a model for escalated alcohol-intake induced by long-term IA exposure to alcohol. The effect of previous experience on operant alcohol SA on two-bottle free choice preference drinking was evaluated and sensitivity to treatment with SR-8993 was tested in rats selected for escalated and non-escalated alcohol seeking behavior. We found that rats exposed to the combined SA-IA paradigm showed greater sensitivity to SR-8993 treatment. In addition, acute escalation of alcohol SA after a three-week period of abstinence was completely abolished by pretreatment with SR-8993. In the third study (Paper III), the effects of the novel, small molecule NPY-Y2 antagonist CYM-9840 were tested in operant alcohol SA, PRR which is a model for motivation to work for alcohol and reinstatement of alcohol-seeking behavior. Treatment with CYM-9840 (10 mg/kg) potently attenuated alcohol SA, progressive ratio responding and stress-induced reinstatement using yohimbine as the stressor, while alcohol cue-induced reinstatement was unaffected. Moreover, a range of control behaviors including taste sensitivity, locomotor and pharmacological sensitivity to the sedative effects of alcohol remained unaffected by CYM-9840 pretreatment, indicating that its effects are specific to the rewarding and motivational aspects of alcohol-intake and related behaviors. CYM-9840 also reversed acute alcohol withdrawal-induced “hangover” anxiety measured in the EPM and reduced alcohol-intake in the 4 hour limited access two-bottle free choice preference drinking model. Finally, in the fourth study (Paper IV), the selective MCH1-R antagonist GW803430 was tested in rat models of escalated alcohol-intake. Pretreatment with GW803430 (effective at 10 & 30 mg/kg) dose-dependently reduced alcohol and food-intake in rats that consumed high amounts of alcohol during IA, while it only decreased food-intake in rats that consumed low amounts of alcohol during IA, likely due to a floor effect. Upon protracted abstinence following IA, GW803430 significantly reduced operant alcohol SA and this was associated with adaptations in MCH and MCH1-R gene-expression. In contrast, GW803430 did not affect escalated alcohol SA induced by chronic alcohol vapor exposure and this was accompanied by no change in MCH or MCH1-R gene expression. Overall, these results suggest that the MCH1-R antagonist affects alcohol-intake through regulation of both motivation for caloric-intake and the rewarding properties of alcohol. In conclusion, our results suggest critical roles for these central neuropeptides in the regulation of anxiety and of alcohol reward, making them potential pharmacological targets in the treatment of AUD.
54

Assessment of embryotoxicity of the antiandrogenic drugs flutamide and bicalutamide in zebrafish (Danio rerio)

Holmlund, Josefin January 2020 (has links)
Introduction: Prostate cancer is the most common type of cancer in Sweden and is often treated using antiandrogenic drug therapy. Two substances belonging to this class of pharmaceuticals are bicalutamide and flutamide. After excretion from the human body, the drug molecules enter the wastewater treatment plant (WWTP). The WWTPs are not effective enough to completely remove pharmaceutical residues, why presence of both bicalutamide and flutamide can be detected in WWTP effluent water. Previous findings: Antiandrogens have been reported to affect reproduction in adult fish, but studies regarding possible effects on the embryonic development of fish are few. Aim: The present study sought to investigate if exposure to bicalutamide or flutamide cause toxicity in the early developmental stages of zebrafish embryos, and whether negative effects occur within concentrations relevant to measured environmental levels. Method: A modified OECD FET-test was used, where additional sublethal endpoints were included and the time period for assessment extended to 144 hours post fertilization (hpf). In addition, a locomotor activity assay was performed at 144 hpf in order to observe any sub-lethal swimming behavioral effects. Results: High doses (10 mg/L) of flutamide led to 100% lethality of the zebrafish embryos but the results suggest no acute toxic effects in the high dose treatment group of bicalutamide, or of either flutamide or bicalutamide within in the low (0.1 mg/L) or intermediate (1 mg/L) treatment groups. Neither did the locomotor activity assay result in statistically significant results, although the pattern of swimming activity in the low dose groups suggests that behavioral developmental effects could be present. Conclusions: High doses of flutamide caused mortality of the embryos, but no lethal or sublethal effects were present at environmentally relevant concentrations. The modest outcome of present study however suggests that further investigation of behavioral developmental effects of antiandrogens could be of future relevance. Analysis of the expression of genes related to neuronal growth, memory and other cognitive behaviors associated with behavioral changes, would then be of interest for further studies.
55

Population Pharmacokinetics of Linezolid for Optimization of the Treatment for Multidrug Resistant Tuberculosis

Hansen, Viktor January 2022 (has links)
Tuberculosis is one the leading causes of death globally and was before the COVID-19 pandemic the leading cause of death from a single infectious agent. Developing active tuberculosis is life threatening and therefore is the rise of drug-resistant tuberculosis alarming as this risk causing current treatments to become ineffective. Linezolid is a promising drug for treatment of drug-resistant pulmonary tuberculosis, but the effect of linezolid treatment for pulmonary tuberculosis subjects is still not understood well enough and the World Health Organization has requested this knowledge gap to be filled. In this project we support the closing of this knowledge gap by describing the pharmacokinetics of linezolid for treatment of pulmonary tuberculosis using data collected from a phase two clinical trial in a South African population. This was done by creating a pop-PK model and resulted in the PK of linezolid in pulmonary tuberculosis patients from South Africa was best described using a one-compartment model, with first-order absorption process preceded by a series of transit compartments and saturable elimination. However, the diagnostics of the model still show that there are room for improvements and future work is necessary to further optimize the model.
56

Digital Image Analysis using Qupath to determine immune cell content in formalin-fixed, paraffin-embedded murine neuroblastoma tumors

Bergström Holm, Anton January 2023 (has links)
Neuroblastoma (NB), an extracranical solid tumor, is among the most prevalent cancers affecting children, particularly those under the age of five. High-risk NB presents a survival rate just below 50 %. Angiogenesis, a crucial process in NB, is induced by various pro-angiogenic factors. The compound SU11657 has demonstrated efficacy in inhibiting angiogenesis and tumor progression. Tumor-associated macrophages (TAMs) and Tumor-associated neutrophils (TANs) contribute to tumor progression, including angiogenesis, and their heightened levels within the tumor has been correlated with a poor clinical prognosis. This study aimed to quantify TANs and TAMs in NB tumors through manual assessment and the development of an automated digital image analysis. Unfortunately, due to time constraints, TAMs were not subjected to detailed analysis. Immunohistochemistry using antibody ab2557 and DAB staining was employed, and cell content analysis was performed through both manual assessment and digital analysis using QuPath. Successful differentiation of TANs was achieved with ab2557. The manual assessment observed a decrease of TANs between the control and treatment groups in UB7 and UB8, with UB7 being statistically significant (p<0.05), based on a two-tailed t-test. QuPath analysis noted increases in the percentages of TANs between the control and treatment groups, with the t-tests being non-significant (p>0.05). While digital image analysis is gaining importance in clinical applications, imperfections persist, underscoring the imperative for further research and development to accurately distinguish biomarkers.
57

Management of chemical risk through occupational exposure limits

Schenk, Linda January 2009 (has links)
Occupational Exposure Limits (OELs) are used as an important regulatory instrument to protect workers’ health from adverse effects of chemical exposures. The OELs mirror the outcome of the risk assessment and risk management performed by the standard setting actor. In paper I the OELs established by 18 different organisations or national regulatory agencies from the industrialised world were compared. The comparison concerned: (1) what chemicals have been selected and (2) the average level of exposure limits for all chemicals. In paper II the OELs established by 7 different national regulatory agencies of EU member states are compared to those of the European Commission (EC). In addition to the same comparisons as performed in the first study a comparison level was introduced (3) the similarity between the OELs of these EU member states and the OELs recommended by the EC. List of OELs were collected through the web-pages of, and e-mail communication with the standard-setting agencies. The selection of agencies was determined by availability of the lists. The database of paper I contains OELs for a total of 1341 substances; of these 25 substances have OELs from all 18 organisations while more than one third of the substances are only regulated by one organisation alone. In paper II this database was narrowed down to the European perspective.  The average level of OELs differs substantially between organisations; the US OSHA exposure limits are (on average) nearly 40 % higher than those of Poland. Also within Europe there was a nearly as large difference. The average level of lists tends to decrease over time, although there are exceptions to this. The similarity index in paper II indicates that the exposure limits of EU member states are converging towards the European Commission’s recommended OELs. These two studies also showed that OELs for the same substance can vary significantly between different standard-setters. The work presented in paper III identifies steps in the risk assessment that could account for these differences. Substances for which the level of OELs vary by a factor of 100 or more were identified and their documentation sought for further scrutiny. Differences in the identification of the critical effect could explain the different level of the OELs for half of the substances. The results reported in paper III also confirm the tendency of older OELs generally being higher. Furthermore, several OELs were more than 30 years old and were based on out-dated knowledge. But the age of the data review could not account for all the differences in data selection, only one fifth of the documents referred to all available key studies. Also the evaluation of the key studies varied significantly.
58

Systemic and local regulation of experimental arthritis by IFN-α, dendritic cells and uridine

Chenna Narendra, Sudeep January 2017 (has links)
In this thesis, we have studied the immunological processes of joint inflammation that may be targets for future treatment of patients with arthritis. We focus on the immune-modulating properties of interferon-α (IFN-α) and uridine in experimental arthritis. The nucleoside uridine, which is regarded a safe treatment has anti-inflammatory properties notably by inhibiting tumor necrosis factor (TNF) release. Because the inflamed synovium in rheumatoid arthritis (RA) is characterised by pathogenic TNF-production, uridine could potentially be away to ameliorate arthritis. Systemic administration of uridine had no effect on antigeninduced arthritis (AIA), which is a T-cell dependent model where animals are immunized twice (sensitization) with bovine serum albumin (mBSA), before local triggering of arthritis by intra-articular antigen (mBSA) re-challenge. In contrast, intra-articular administration of uridine clearly down modulated development of AIA in a dose dependent manner and inhibited the expression of synovial adhesion molecules, influx of inflammatory leukocytes and synovial expression of TNF and interleukin 6, but did not affect systemic levels of proinflammatory cytokines or antigen-specific T-cell responses. Local administration of uridine may thus be a viable therapeutic option for treatment of arthritis in the future. Viral double-stranded deoxyribonucleic acid (dsRNA), a common nucleic acid found in most viruses, can be found in the joints of RA patients and local deposition of such viral dsRNA induces arthritis by activating IFN-α. Here we show that arthritis induced by dsRNA can be mediated by IFN-producing dendritic cells in the joint and this may thus explain why viral infections are sometimes associated with arthritis. Earlier, to study the effect of dsRNA and IFN-α in an arthritis model, that like RA, is dependent on adaptive immunity, dsRNA and IFN-α were administered individually during the development of AIA. Both molecules clearly protected against AIA in a type I IFN receptor-dependent manner but were only effective if administered in the sensitization phase of AIA. Here we show that the anti-inflammatory effect of IFN-α is critically dependent on signalling via transforming growth factor β (TGF-β) and the enzymatic activity of indoleamine 2,3 dioxygenase 1 (IDO). The IDO enzyme is produced by plasmacytoid DC and this cell type was critically required both during antigen sensitization and in the arthritis phase of AIA for the protective effect of IFN-α against AIA. In contrast, TGF-β and the enzymatic activity of IDO were only required during sensitization, which indicate that they are involved in initial steps of tolerogenic antigen sensitization. In this scenario, IFN- α first activates the enzymatic activity of IDO in pDC, which converts Tryptophan to Kynurenine, which thereafter activates TGF-β. Common for IDO-expressing pDC, Kyn and TGF-β is their ability to induce development of regulatory T cells (Tregs). We found that Tregs were crucial for IFN-α-mediated protection against AIA, but only in the arthritis phase. In line with this, adoptive transfer of Tregs isolated from IFN-α treated mice to recipient animals in the arthritis phase clearly protected against AIA. The numbers of Tregs were not significantly altered by IFN-α but IFN-α increased the suppressive capacity of Tregs against antigen-induced proliferation. This enhanced suppressive activity of Tregs in the arthritis phase was dependent on the earlier activated enzyme IDO1 during the sensitization phase of AIA. Thus, presence of IFN-α at the time of antigen sensitization activates the enzymatic activity of IDO, which generates Tregs with enhanced suppressive capacity that upon antigen re-challenge prevents inflammation. We have thus identified one example of how immune tolerance can be developed, that may be a future way to combat autoimmunity.
59

Studies on anti-leukemic terpenoids from medicinal mushrooms and marine sponges with ChemGPS-NP-based targets investigation of lead compounds

Lai, Kuei-Hung January 2017 (has links)
This thesis investigates the anti-leukemic activity of terpenoids isolated from medicinal mushrooms and marine sponges, as well as their possible targets and mechanisms of action. In the first section, we focused on studying the triterpenoidal components of three triterpenoid-enriched medicinal mushrooms Antrodia cinnamomea, Ganoderma lucidum, and Poria cocos, which have been used in folk medicine for centuries and also developed into several contemporary marketed products. We isolated the major and characteristic triterpenoids from these mushrooms, together with six new lanostanoids (II-1–II-6). The anti-leukemic activity of the isolates was evaluated in vitro using MTT proliferative assay and seven of them exhibited potential anti-leukemic effect. The active lead compounds were further subjected to computational analyses utilizing the ChemGPS-NP tool. We established a database for the anti-leukemic relevant chemical space of triterpenoids isolated from these three medicinal mushrooms, which could be used as a reference database for further research on anti-leukemic triterpenoids. Our results indicated that the anti-leukemic effect of the active lead compounds was mediated not only through topoisomerases inhibition but also through inhibiting DNA polymerases. The second and third sections focused on isolation of anti-leukemic sesterterpenoids from sponges. The investigation of Carteriospongia sp. led to the isolation of two new scalarane-type sesterterpenoids (III-1 and III-2) and one known tetraprenyltoluquinol-related metabolite (III-3). All isolates exhibit an apoptotic mechanism of action against Molt 4 cells, found to be mediated through the disruption of the mitochondrial membrane potential (MMP) and inhibition of topoisomerase IIα expression. Detailed investigation of the apoptotic mechanism of action using molecular docking analysis revealed that compound III-1 might target Hsp90 protein. The apoptotic-inducing effect of III-3 was supported by in vivo experiment by suppressing the volume of xenograft tumor growth (47.58%) compared with the control. In the final section of this thesis we studied manoalide and its derivatives, sesterterpenoids isolated from the sponge Luffariella sp.. Manoalide has been studied as a potential anti-inflammatory agent for the last thirty years with more than 200 publications and 40 patents. However, the configurations at positions 24 and 25 were never revealed. In the current study, ten manoalide-type sesterterpenoids (IV-1–IV-10) were isolated from Luffariella sp. and their stereoisomers at positions 24 and 25 were identified and separated for the first time. The configuration at positions 24 and 25 showed to have a significant effect on the anti-leukemic activity of manoalide derivatives, with the 24R,25S-isomer exhibiting the most potent anti-leukemic activity. The apoptotic mechanism of action of compound IV-7 against Molt 4 cells was investigated, and the compound was found to trigger MMP disruption and intracellular reactive oxygen species (ROS) generation. Compound IV-7 also inhibited activity against both human topoisomerases, I and II. The in vivo experiment further supported the anti-leukemic effect of IV-7 with a 66.11% tumor volume suppression compared to the control.
60

In vitro cellular models for neurotoxicity studies : neurons derived from P19 cells

Popova, Dina January 2017 (has links)
Humans are exposed to a variety of chemicals including environmental pollutants, cosmetics, food preservatives and drugs. Some of these substances might be harmful to the human body. Traditional toxicological and behavioural investigations performed in animal models are not suitable for the screening of a large number of compounds for potential toxic effects. There is a need for simple and robust in vitro cellular models that allow high-throughput toxicity testing of chemicals, as well as investigation of specific mechanisms of cytotoxicity. The overall aim of the thesis has been to evaluate neuronally differentiated mouse embryonal carcinoma P19 cells (P19 neurons) as a model for such testing. The model has been compared to other cellular models used for neurotoxicity assessment: retinoic acid-differentiated human neuroblastoma SH-SY5Y cells and nerve growth factor-treated rat pheochromocytoma PC12 cells. The chemicals assessed in the studies included the neurotoxicants methylmercury, okadaic acid and acrylamide, the drug of abuse MDMA (“ecstasy”) and a group of piperazine derivatives known as “party pills”. Effects of the chemicals on cell survival, neurite outgrowth and mitochondrial function have been assessed. In Paper I, we describe a fluorescence-based microplate method to detect chemical-induced effects on neurite outgrowth in P19 neurons immunostained against the neuron-specific cytoskeletal protein βIII-tubulin. In Paper II, we show that P19 neurons are more sensitive than differentiated SH-SY5Y and PC12 cells for detection of cytotoxic effects of methylmercury, okadaic acid and acrylamide. Additionally, in P19 neurons and differentiated SH-SY5Y cells, we could demonstrate that toxicity of methylmercury was attenuated by the antioxidant glutathione. In Paper III, we show a time- and temperature-dependent toxicity produced by MDMA in P19 neurons. The mechanisms of MDMA toxicity did not involve inhibition of the serotonin re-uptake transporter or monoamine oxidase, stimulation of 5-HT2A receptors, oxidative stress or loss of mitochondrial membrane potential. In Paper IV, the piperazine derivatives are evaluated for cytotoxicity in P19 neurons and differentiated SH-SY5Y cells. The most toxic compound in both cell models was TFMPP. In P19 neurons, the mechanism of action of TFMPP included loss of mitochondrial membrane potential. In conclusion, P19 neurons are a robust cellular model that may be useful in conjunction with other models for the assessment of chemical-induced neurotoxicity.

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