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Preclinical Development of New Alkylating Oligopeptides for Cancer TherapyGullbo, Joachim January 2003 (has links)
Oligopeptides can be used to carry cytotoxic agents in cancer chemotherapy, using tumour-associated proteins as the molecular target for selectivity. During the seventies and eighties Peptichemio, a cocktail of six alkylating oligopeptides carrying m-L-sarcolysin, was investigated in a wide variety of human malignancies. Positive clinical results were suggested to result from rapid and effective DNA-crosslinking following uptake in neoplastic cells, but also from antimetabolic properties of the drug. Although m-L-sarcolysin never reached widespread clinical use, the well established para-isomer melphalan still, after nearly fifty years, has a place in cancer chemotherapy. The present study was undertaken to synthesise the melphalan containing analogue of the tripeptide P2 (L-prolyl-m-L-sarcolysyl-p-L-fluorophenylalanine ethyl ester, the main contributor to Peptichemio’s activity) and similar compounds, preferably dipeptides. The new compounds compared favourably with melphalan, m-L-sarcolysin and P2, considering their potency in vitro. Structure activity relationship analysis showed that the activity of melphalan dipeptides depended on the amino acid composition, sequence and end group modifications, but only to a minor degree on lipophilicity. Results suggested that the dipeptides, to exert their full cytotoxic activity, had to interact with specific biomolecules such as dipeptide transporters or peptidases. Although no active transport could be demonstrated the influence of peptide hydrolysis was obvious, thereby suggesting a rationale for increased activity as well as potential tumour selectivity in comparison with melphalan. Preliminary in vivo studies in mice supported the results, despite equal alkylating capacity the dipeptide J1 (melphalanyl-p-L-fluorophenylalanine ethyl ester) and the tripeptide J3 (L-prolyl-melphalanyl-p-L-fluorophenylalanine ethyl ester) were more active than was melphalan on human tumour cells implanted in test animals although all drugs produced expected side effects, notably leukopenia, of similar magnitude. In conclusion, oligopeptide derivatives of melphalan seem to provide improved cytotoxic activity and therapeutic index. Further development of such oligopeptides for clinical use seems worthwhile.
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Cellular Pharmacology of the Novel Antitumoural Cyanoguanidine CHS 828Lövborg, Henrik January 2004 (has links)
The antitumoural cyanoguanidine CHS 828 has shown promising activity in a number of preclinical and clinical studies. However, the mechanisms underlying the cell death induced by CHS 828 has not been clarified. This thesis describes in vitro studies of the cellular pharmacology of CHS 828. CHS 828 induced cell death with necrosis like features in the lymphoma cell line U-937 GTB. Addition of 3-aminobenzamide, an inhibitor of ADP-ribosylation, resulted in a decreased sensitivity to CHS 828 and a shift in the mode of cell death towards apoptosis. Mouse fibroblasts lacking the enzyme PARP-1 were more sensitive to CHS 828 compared to normal fibroblasts. CHS 828 was able to induce p53 in normal fibroblasts but this effect does not seem to be necessary to induce cell death. Characterization of two CHS 828 resistant cell lines indicated that they were selectively resistant to cyanoguanidines. Known mechanisms of anticancer drug resistance did not seem to account for the cyanoguanidine resistance. One possible resistance mediating protein, which was upregulated in the resistant cells, was epidermal fatty acid binding protein. A novel high content screening assay was also developed. The assay was shown to be suitable both for screening of potential novel antitumoural substances as well for mechanistic studies. In the assay, CHS 828 induced caspase-3 activity and reduction in mitochondrial membrane potential, both signs of apoptosis, in U-937 GTB cells. However, nuclei in exposed cells did not show nuclear fragmentation, one of the hallmarks of apoptosis. CHS 828 was also shown to indirectly inhibit the proteasome activity in U-937 GTB cells. In conclusion, the results presented provide new insights into the metabolic and molecular events involved in cell death induced by CHS 828.
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Transcription Factor AP-2 in Relation to Personality and Antidepressant DrugsBerggård, Cecilia January 2004 (has links)
The CNS monoaminergic systems are considered as the head engine regulating neuropsychiatric functions and personality. Transcription factor AP-2 is known to be essential for the development of the brainstem including the monoaminergic nuclei, and has the ability to regulate many genes in the monoaminergic systems. The ability of transcription factors to regulate specific gene expression, has lately made them hot candidates as drug targets. In this thesis, results indicating a role of AP-2 in the molecular effects of the antidepressant drugs citalopram and phenelzine, are presented. A polymorphism in the second intron of the gene encoding AP-2ß has previously been associated with anxiety-related personality traits as estimated by the Karolinska Scales of Personality (KSP). In this thesis, results confirming this association, gained by using a larger material and several different personality scales, are presented. Furthermore, data is presented showing an association between the activity of platelet monoamine oxidase, a trait-dependent marker for personality, and the genotype of the AP-2ß intron 2 polymorphism. The functional importance of the AP-2ß intron 2 polymorphism has not yet been elucidated. Included in this thesis are results showing that the AP-2ß intron 2 polymorphism is not in linkage disequilibrium with the only other described polymorphism in the AP-2ß gene, i.e. in the AP-2ß promoter (-67 G/A). Introns have in several studies been shown to include binding sites for regulatory proteins, and thus, to be important in transcriptional regulation. Results are presented demonstrating that one human brain nuclear protein binds only to the long variant of the AP-2ß intron 2 polymorphism. If this protein is involved in the regulation of the AP-2ß gene, it would affect the expression levels of the AP-2ß protein. In general, this thesis further establishes the role of transcription factor AP-2 as a regulatory factor of importance for personality and monoaminergic functions.
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Semicarbazide-sensitive Amine Oxidase (SSAO) – Regulation and Involvement in Blood Vessel Damage with Special Regard to Diabetes : A Study on Mice Overexpressing Human SSAOGöktürk, Camilla January 2004 (has links)
Semicarbazide-sensitive amine oxidase (SSAO, EC 1.4.3.6) belongs to a family of copper-containing amine oxidases. SSAO exists as a membrane bound protein in endothelial-, smooth muscle-, and adipose cells as well as soluble in plasma. SSAO catalyses oxidative deamination of primary monoamines, which results in the production of corresponding aldehydes, hydrogen peroxide and ammonia. These compounds are very reactive and potentially cytotoxic, and are able to induce vascular damage if produced in high levels. Patients with diabetes mellitus, and with diabetic complications in particular, have a higher SSAO activity in plasma compared to healthy controls. It has therefore been speculated that high SSAO activity is involved in the development of vascular complications associated with diabetes. The aim of this thesis is to investigate the importance of SSAO in the development of disorders of a vascular origin. We have studied the transcriptional regulation of the SSAO gene, by inducing diabetes in NMRI and in transgenic mice, overexpressing the human form of SSAO in smooth muscle cells. We found that the increase in SSAO activity in diabetes is accompanied by reduced mRNA levels of the endogenous mouse gene, suggesting a negative feedback on the transcription of the SSAO gene. In addition, the transgenic mice exhibited an abnormal phenotype in the elastic tissue of aorta and renal artery. These mice have a lower mean artery pressure and an elevated pulse pressure. These results indicate that high SSAO activity in smooth muscle cells is associated with a change in the morphology of large arteries. This is likely contributing to the development of vascular complications in diabetes.
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Methods for Preclinical Evaluation of Cytotoxic Drugs : With Special Reference to the Cyanoguanidine CHS 828 and Hollow Fiber MethodHassan, Saadia Bashir January 2004 (has links)
The novel cyanoguanidine CHS 828 has shown promising antitumor activity in many in vitro and in vivo studies. The long-term 14 days in vitro hollow fiber cultures, where tumor cells from different tumor cell lines were cultured inside semipermeable fibers, were more resistant to CHS 828 and other cytotoxic drugs than the shorter-term 3 days cultures. CHS 828 was generally more effective against haematological than solid tumor cells from both cell lines and patients samples. In vivo, the hollow fibers were implanted into immunocompetent rats and the pharmacokinetics, tumor response and/or toxicity (pharmacodynamics) of CHS 828 were successfully assayed. CHS 828 showed higher activity in this model when a more protracted schedule was used. The quantitative relationships between dose, plasma concentration and response (PK/PD model) developed for CHS 828 explained this phenomenon partly by dose-dependent fraction absorbed and partly by a schedule-dependent pharmacodynamic effect. Modelling of the in vitro CHS 828 and standard cytotoxic drugs concentration-time effect data in different tumor cell types and characterization of pattern of change of the potency and the slope of the concentration-time effect curves were performed. The results suggest two different mechanisms of action for CHS 828 and that CHS 828 cytotoxicity may depend on the schedule used. The NF-kB pathway that regulates the transcription of anti-apoptotic genes proved to be inhibited by CHS 828 in different tumor cell lines and the inhibition was correlated to the cell death induced by this agent. CHS 828 did not seem to induce the NF-kB inhibition by affecting the proteasome activity. The in vitro and in vivo hollow fiber methods were also used successfully to evaluate the new paclitaxel formulation, Pacliex. Pacliex had a similar activity to that of the clinically used formulation Taxol®.
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Ribosome Associated Factors Recruited for Protein Export and FoldingRaine, Amanda January 2005 (has links)
Protein folding and export to the membrane are crucial events in the cell. Both processes may be initiated already at the ribosome, assisted by factors that bind to the polypeptide as it emerges from the ribosome. The signal recognition particle (SRP) scans the ribosome for nascent peptides destined for membrane insertion and targets these ribosomes to the site for translocation in the membrane. Trigger factor (TF) is a folding chaperone that interacts with nascent chains to promote their correct folding, prevent misfolding and aggregation. In this thesis, we first investigated membrane targeting and insertion of two heterologous membrane proteins in E. coli by using in vitro translation, membrane targeting and cross-linking. We found that these proteins are dependent on SRP for targeting and that they initially interact with translocon components in the same way as native nascent membrane proteins. Moreover we have characterised the SRP and TF interactions with the ribosome both with cross-linking experiments and with quantitative binding experiments. Both SRP and TF bind to ribosomal L23 close to the nascent peptide exit site where they are strategically placed for binding to the nascent polypeptide. Quantitative analysis of TF and SRP binding determined their respective KD values for binding to non translating ribosomes and reveals that they bind simultaneously to the ribosome, thus having separate binding sites on L23. Finally, binding studies on ribosome nascent chain adds clues as to how TF functions as a chaperone.
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Hazards of Drug Therapy : On the Management of Adverse Drug Reactions: From Signal Detection and Evaluation to Risk MinimizationHedenmalm, Karin January 2005 (has links)
Spontaneous reporting systems (SRSs) for adverse drug reactions (ADRs) have been developed as a result of the thalidomide disaster, whereby thousands of children world-wide were born with birth defects. The Swedish Adverse Drug Reactions Advisory Committee was established in 1965. Since 1975, reporting has been compulsory for all suspected serious or new ADRs. International collaboration started in 1968 with countries contributing their ADR reports to an international database set up by the World Health Organization. ADRs represent the negative side of the benefit-to-risk balance that in theory needs to be counteracted by perceived or established positive drug effects. All drugs are subject to preclinical and clinical testing prior to marketing authorization. However, these studies are insufficient to detect rare ADRs, ADRs that occur after long-term administration or with latency, ADRs that occur in special patient groups such as children, the elderly, patients with renal or hepatic insufficiency or patients on concomitant drug treatment, and ADRs that represent a modest increase in the risk of diseases (including mortality) that are prevalent in the study population. Postmarketing surveillance of drugs is therefore essential, and regulatory action may be needed on the basis of new ADR information. SRSs are important sources of ADR information as exemplified here by the evaluation of peripheral sensory disturbances with fluoroquinolones, hyponatremia with antidepressants, blood dyscrasias with dipyrone, glucose intolerance with atypical antipsychotics, pulmonary embolism with combined oral contraceptives and extrapyramidal symptoms with selective serotonin reuptake inhibitors. SRSs can be used to study clinical manifestations of ADRs (that can give insights into potential ADR mechanisms), risk factors for the ADR or for specific outcomes of the ADR, and ADR reporting incidences when combined with sales data. Signals from SRSs may need to be studied further e.g., by use of large-scale epidemiologic studies based on record linkage between drug prescription databases and health databases. Owing to the rapid availability of information, however, SRSs are likely to remain of major importance for the post-marketing surveillance of drugs.
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Pharmacology of Palmitoylethanolamide and Related CompoundsJonsson, Kent-Olov January 2005 (has links)
Anandamide (AEA) is an endogenous fatty acid which activates the same cannabinoid receptors as ∆9-tetrahydrocannabinol, the psychoactive substance in marijuana. In vivo, anandamide exerts a number of actions including effects upon pain and inflammation. However, AEA has a short duration of action since it is rapidly metabolised, primarily by the intracellular enzyme fatty acid amide hydrolase (FAAH). The general aim of this thesis has been to identify and characterize compounds capable of preventing the metabolism of anandamide. The chemical approach was based on the endogenous anti-inflammatory compound palmitoylethanolamide (PEA), a compound related to anandamide with the ability to inhibit anandamide degradation by substrate competition, but without the ability to directly activate cannabinoid receptors. A number of compounds were identified as inhibitors of rat brain FAAH in the initial in vitro studies, without having major affinity for the cannabinoid receptors. In particular, palmitoylisopropylamide (PIA) was found to reduce the metabolism of AEA in intact C6 glioma cells with potency similar to the prototypical AEA reuptake inhibitor AM404. This compound was in addition found to exert less effect upon C6 glioma cell proliferation than either AM404 or the closely related uptake inhibitor VDM11. To evaluate if PIA was effective in vivo, a model of mast cell dependent inflammation, oedema of the ear following local injection of compound 48/80, was set up using anaesthetised mice. Initially, a CB2 cannabinoid receptor selective agonist was used to probe the model and demonstrated to produce an anti-oedema effect. In contrast, the compound was inactive in vitro in skin slice preparations. PIA showed a similar pattern, although there was a large variation in responses which affected the significance of the result obtained, as did the vehicle used to dissolve the compound. Taken together, the present data would suggest that PIA can inhibit the degradation of AEA without having deleterious effects upon cell proliferation or affinity for the cannabinoid receptors. Further experimentation is necessary to elucidate the usefulness of this compound in vivo.
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Fatty acid amide hydrolase - A target for anti-inflammatory therapies? / Fettsyraamidohydrolas - Ett mål för antiinflammatoriska läkemedel?Holt, Sandra January 2005 (has links)
Anti-inflammatory drugs are a widely used class of therapeutic agents, but the use of non-steroidal anti-inflammatory drugs (NSAID) is hampered by their gastrointestinal side-effects. Recent reports that cyclooxygenase-2 inhibitors may cause cardiovascular events underline the importance of identifying new therapeutic strategies for the treatment of inflammation. One such target could be agents modifying the endogenous cannabinoid (endocannabinoid) system, since there is evidence that this system plays a role in our natural defence against inflammation. The levels of the endocannabinoid anandamide (arachidonoyl ethanolamide, AEA) are low under normal conditions, and stand under strict regulatory control of synthesising and degrading enzymes. Fatty acid amide hydrolase (FAAH) is the main enzyme degrading AEA, hydrolysing it to ethanolamine and arachidonic acid. The focus of this thesis lies in exploring the pharmacology of FAAH to evaluate its possibilities as a target for new anti-inflammatory drugs. In Papers I and II, the effects of the ambient pH on the properties of FAAH were investigated, since tissue pH is known to decrease under inflammatory conditions. In homogenates, it was found that the activity of FAAH decreased as the assay pH was decreased, consistent with the known pH profile of the enzyme. More importantly, the sensitivity of the enzyme to inhibition by FAAH inhibitors changed. In particular, the sensitivity of the enzyme to inhibition by the NSAID ibuprofen increased seventeen-fold as the assay pH decreased from 8.37 to 5.28. A similar pattern was found using intact C6 glioma cells when the extracellular, but not the intracellular pH was reduced. Thus, at an extracellular pH value of 6.2, (R)-ibuprofen, (S)-flurbiprofen and (R,S)-flurbiprofen inhibited the metabolism of AEA with IC50 values of 26, 14 and 15 µM, respectively. These values are in theory reachable upon normal dosing of the compounds. In Paper III, the effect of the selective FAAH inhibitor URB597 and the NSAID indomethacin were investigated in vivo upon the oedema response to carrageenan administration in the paw of anaesthetised mice. Both compounds reduced the oedema in a manner completely blocked by the CB2 receptor antagonist SR144528. In Paper IV, the effect of inflammation upon endocannabinoid synthesis was investigated in mice. Lipopolysaccharide-induced pulmonary inflammation was found not to affect the release of AEA to any obvious extent, and did not change the activities of the AEA synthesising enzymes N-acyl transferase or N-acyl phosphatidylethanolamine phospholipase D, or of FAAH in lung tissue. The results of this thesis would suggest that FAAH inhibitors can produce anti-inflammatory effects, and that the endocannabinoid system contributes to the actions of the NSAID indomethacin in the carrageenan model of inflammation, but that an increased endocannabinoid synthesis (a prerequisite for FAAH inhibition as a therapeutic strategy) is not an obligatory response to an inflammatory stimulus.
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Individers erfarenhet av icke farmakologisk behandling vid långvarig smärta : En litteraturöversiktGedda, Hanna, Krantz, Karolina January 2013 (has links)
Aim: The aim of this study was to highlighting the experiences of individuals of non-pharmacological treatment for chronic pain. Method: The study was designed as a literature review with aim to review and compile the articles results. This study has been based on a systematic literature search of supplementing out of an unsystematic search were 11 articles were found. Results: The participants in the studies had experienced a good effect out of non-pharmacological treatments for their pain and a improved quality of life. Based on participants´ experiences of treatment two categories occurred: body awareness and relaxation. Body awareness arose through treatments like yoga, mindfulness meditation and CBT. Relaxation occurred through treatments, like music, heat, massage and meditation. Conclusion: This study highlights how non-pharmacological treatments is experienced by individuals with chronic pain and two key areas have been identified. This study thereby contributes with important knowledge for nurses in their nursing with individuals suffering from chronic pain.
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