Structure-activity relationship analysis of cytotoxic cyanoguanidines: selection of CHS 828 as candidate drug

<p>Abstract</p> <p>Background</p> <p><it>N</it>-(6-(4-chlorophenoxy)hexyl)-<it>N</it>'-cyano-<it>N''</it>-4-pyridyl guanidine) (CHS 828) is the first candidate drug from a novel group of anti-tumour agents – the pyridyl cyanoguanidines, shown to be potent compounds interfering with cellular metabolism (inhibition of nicotinamide phosphoribosyl transferase) and NF-κB signalling. Substituted cyanoguanidines are also found in anti-hypertensive agents such as the potassium channel opener pinacidil (<it>N</it>-cyano-<it>N'</it>-(4-pyridyl)-<it>N''</it>-(1,2,2-trimethylpropyl)guanidine) and histamine-II receptor antagonists (e.g. cimetidine, <it>N</it>-cyano-<it>N'</it>-methyl-<it>N''</it>-[2-[[(5-methylimidazol-4-yl]methyl]thio]ethyl)guanidine). In animal studies, CHS 828 has shown very promising activity, and phase I and II studies resulted in further development of a with a water soluble prodrug.</p> <p>Findings</p> <p>To study the structural requirements for cyanoguanidine cytotoxicity a set of 19 analogues were synthesized. The cytotoxic effects were then studied in ten cell lines selected for different origins and mechanisms of resistance, using the fluorometric microculture cytotoxicity assay (FMCA). The compounds showed varying cytotoxic activity even though the dose-response curves for some analogues were very shallow. Pinacidil and cimetidine were found to be non-toxic in all ten cell lines. Starting with cyanoguanidine as the crucial core it was shown that 4-pyridyl substitution was more efficient than was 3-pyridyl substitution. The 4-pyridyl cyanoguanidine moiety should be linked by an alkyl chain, optimally a hexyl, heptyl or octyl chain, to a bulky end group. The exact composition of this end group did not seem to be of crucial importance; when the end group was a mono-substituted phenyl ring it was shown that the preferred position was 4-substitution, followed by 3- and, finally, 2-substitution as the least active. Whether the substituent was a chloro, nitro or methoxy substituent seemed to be of minor importance. Finally, the activity patterns in the ten cell lines were compared. Substances with similar structures correlated well, whilst substances with large differences in molecular structure demonstrated lower correlation coefficients.</p> <p>Conclusion</p> <p>According to this structure-activity relationship (SAR) study, CHS 828 meets the requirements for optimal cytotoxic activity for this class of compounds.</p

Development of the Liverpool Adverse Drug Reaction Avoidability Assessment Tool

Aim To develop and test a new tool to assess the avoidability of adverse drug reactions that is suitable for use in paediatrics but which is also applicable to a variety of other settings. Methods The study involved multiple phases. Preliminary work involved using the Hallas scale and a modification of the existing Hallas scale, to assess two different sets of adverse drug reaction (ADR) case reports. Phase 1 defined, modified and refined a new tool using multidisciplinary teams. Phase 2 involved the assessment of 50 ADR case reports from a prospective study of paediatric inpatients by individual assessors. Phase 3 compared assessments with the new tool for individuals and groups in comparison to the ‘gold standard’ (the avoidability outcome set by a panel of senior investigators: an experienced clinical pharmacologist, paediatrician and pharmacist). Main Outcome Measures Inter-rater reliability (IRR), measure of disagreement and utilization of avoidability categories. Results Preliminary work—Pilot phase: results for the original Hallas cases were fair and pairwise kappa scores ranged from 0.21 to 0.36. Results for the modified Hallas cases were poor, pairwise kappa scores ranged from 0.06 to 0.16. Phase 1: on initial use of the new tool, agreement between the two multidisciplinary groups was found on 13/20 cases with a kappa score of 0.29 (95% CI -0.04 to 0.62). Phase 2: the assessment of 50 ADR case reports by six individual reviewers yielded pairwise kappa scores ranging from poor to good 0.12 to 0.75 and percentage exact agreement (%EA) ranged from 52–90%. Phase 3: Percentage exact agreement ranged from 35–70%. Overall, individuals had better agreement with the ‘gold standard’. Conclusion Avoidability assessment is feasible but needs careful attention to methods. The Liverpool ADR avoidability assessment tool showed mixed IRR. We have developed and validated a method for assessing the avoidability of ADRs that is transparent, more objective than previous methods and that can be used by individuals or groups

Démonétisation en Russie:Un arbitrage favorable au maintien de l’emploi

Un arbitrage favorable au maintien de l'emploi La démonétisation de l'économie russe est le produit d'une politique monétaire restrictive conjuguée au maintien de la contrainte budgétaire douce. L'État, qui autorise les arriérés fiscaux ou l'acquittement des impôts en nature, et les entreprises, qui accumulent des arriérés salariaux, arbitrent à court terme en faveur du maintien de l'emploi dans des entreprises qui diffèrent la restructuration. Le chômage est corrélé positivement à long terme aux arriérés fiscaux et salariaux, mais à court terme l'augmentation de ces derniers influence positivement l'évolution de l'emploi.The increase in non-monetary payments in Russia is the output of both a tight monetary policy and the persistence of the soft budget constraint. The State, by allowing fiscal arrears and in-kind payments, and the enterprises, by using wage arrears as a way of accommodating the budget constraint, make a short term arbitrage which favours the level of employment and further delay in restructuring. Unemployment is positively correlated in the long run with fiscal and wage arrears, but in the short run, any increase in the latter has a positive impact on the fluctuation of employment

A conceptually new treatment approach for relapsed glioblastoma: Coordinated undermining of survival paths with nine repurposed drugs (CUSP9) by the International Initiative for Accelerated Improvement of Glioblastoma Care.

To improve prognosis in recurrent glioblastoma we developed a treatment protocol based on a combination of drugs not traditionally thought of as cytotoxic chemotherapy agents but that have a robust history of being well-tolerated and are already marketed and used for other non-cancer indications. Focus was on adding drugs which met these criteria: a) were pharmacologically well characterized, b) had low likelihood of adding to patient side effect burden, c) had evidence for interfering with a recognized, well-characterized growth promoting element of glioblastoma, and d) were coordinated, as an ensemble had reasonable likelihood of concerted activity against key biological features of glioblastoma growth. We found nine drugs meeting these criteria and propose adding them to continuous low dose temozolomide, a currently accepted treatment for relapsed glioblastoma, in patients with recurrent disease after primary treatment with the Stupp Protocol. The nine adjuvant drug regimen, Coordinated Undermining of Survival Paths, CUSP9, then are aprepitant, artesunate, auranofin, captopril, copper gluconate, disulfiram, ketoconazole, nelfinavir, sertraline, to be added to continuous low dose temozolomide. We discuss each drug in turn and the specific rationale for use- how each drug is expected to retard glioblastoma growth and undermine glioblastoma's compensatory mechanisms engaged during temozolomide treatment. The risks of pharmacological interactions and why we believe this drug mix will increase both quality of life and overall survival are reviewed

Identification of molecular mechanisms for cellular drug resistance by combining drug activity and gene expression profiles

Acquired drug resistance is a major problem in cancer treatment. To explore the genes involved in chemosensitivity and resistance, 10 human tumour cell lines, including parental cells and resistant subtypes selected for resistance against doxorubicin, melphalan, teniposide and vincristine, were profiled for mRNA expression of 7400 genes using cDNA microarray technology. The drug activity of 66 cancer agents was evaluated on the cell lines, and correlations between drug activity and gene expression were calculated and ranked. Hierarchical clustering of drugs based on their drug–gene correlations yielded clusters of drugs with similar mechanism of action. Genes correlated with drug sensitivity and resistance were imported into the PathwayAssist software to identify putative molecular pathways involved. A substantial number of both proapoptotic and antiapoptotic genes such as signal transducer and activator of transcription 1, mitogen-activated protein kinase 1 and focal adhesion kinase were found to be associated to drug resistance, whereas genes linked to cell cycle control and proliferation, such as cell division cycle 25A and signal transducer of activator of transcription 5A, were associated to general drug sensitivity. The results indicate that combined information from drug activity and gene expression in a resistance-based cell line panel may provide new knowledge of the genes involved in anticancer drug resistance and become a useful tool in drug development

Increase the web accessibility through WCAG's standards for users with disabilities : An implementation of accessible code in LenaSys

Webben har stor betydelse för vårt samhälle, och det är därför viktigt att den är tillgänglig för alla. Personer med någon form av funktionsvariation är en grupp som tidigare inte inkluderats i utformningen och utvecklingen av webben, men det finns idag en lagstiftning om digital tillgänglighet. I den här studien har lagstiftningen inspirerat till idén om att alla studerande ska ha samma utbildningsmöjligheter. Studien syftar till att skapa en tillgängligare webb för studerande, genom att undersöka två aspekter av tillgänglighet på webben. LenaSys, Högskolan i Skövdes lärplattform, har använts föratt undersöka vilken påverkan tillgänglighetsanpassad kod kommer att ha på den ursprungliga programkoden, och vilken påverkan tillgänglighetsanpassningen kommer ha på webbsidans svarstid. Resultatet indikerade att tillämpning av tillgänglighetsanpassad programkod ökade mängden data på sidan och gav en längre svarstid. Samtidigt innebär implementering av tillgänglighetsanpassad kod små förändringar för en utvecklare men stora förbättringar för en person med en funktionsvariation

Cellular Pharmacology of the Novel Antitumoural Cyanoguanidine CHS 828

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

Cellular Pharmacology of the Novel Antitumoural Cyanoguanidine CHS 828

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