Orientador: Gilberto de Nucci / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-14T20:52:52Z (GMT). No. of bitstreams: 1 Silva_RenatoMedeiros_M.pdf: 5432076 bytes, checksum: abb10d1ceb928cd0c634eae336f2d154 (MD5) Previous issue date: 2009 / Resumo: Esta dissertação irá focar na avaliação da bioequivalência de duas formulações do Losartan Potássico (50mg) comprimidos de liberação imediata (Losartan do Laboratório Cristália Ltda, Brasil, como formulação teste e Cozaar® da Merck Sharp & Dohme Farmacêutica Brasil como formulação referência). A bioequivalência foi conduzida usando um estudo aberto, randomizado, cruzado de duas fases com um intervalo de washout de 1 semana. Foram utilizados 25 voluntários de ambos os sexos. As amostras de plasma foram obtidas sobre um período de 24 horas. As concentrações plasmáticas do Losartan e seu metabolito ativo Losartan Ácido foram determinadas por cromatografia líquida de fase reversa acoplada à espectrometria de massa (LC-MS-MS), com modo de ionização electrospray negativo usando o monitoramento de múltiplas reações (MRM). Das curvas de concentração plasmática versus o tempo para Losartan e Losartan Ácido, os seguintes parâmetros farmacocinéticos foram obtidos: AUClast, AUCo-inf e Cmax. Resultados: A média geométrica e o respectivo intervalo de confiança de 90% Losartan / Cozaar® para o Losartan foram: 92,9% (82,2 - 105,0%) para Cmax,, 99,0% (92,5 -105,9%) para AUClast, e 99,1% (92,7 - 105,8%) para AUC0-M,. Alem disso, a média geométrica e a respectivo intervalo de confiança de 90% Losartan / Cozaar® para o Losartan Ácido foram: 98,5% (91,5 - 106,0%) para Cmax, 97,9% (93,3 - 102,7%) para AUClast, e 98,1% (93,5 - 102,9%) para AUC0-M Utilizando um IC de 90% para AUClast, AUC0-M e Cmax dentro do intervalo de 80125% proposto pelo FDA (USA). As duas formulações foram bioequivalentes para a taxa e velocidade de absorção, para o medicamento Losartan 50 mg comprimidos de liberação imediata. Além disso, não foi apresentada nenhuma diferença significante entre a determinação de bioequivalência entre o Losartan e o Losartan Ácido, portanto, futuras bioequivalências, deste medicamento, poderão ser realizadas apenas para o Losartan, sendo assim mais discriminatório / Abstract: This dissertation focus in the evaluation of the bioavailability of two formulations of potassium losartan immediate release tablet 50mg (Losartan from Laboratórios Cristália Ltd., Brazil, as a test formulation and Cozaar® from Merck Sharp & Dohme Farmacêutica Ltd., Brazil as a reference formulation). The bioequivalence study was conducted using an open, randomized, in a two-period crossover design and a one week washout period. Plasma samples were obtained over a 24hour interval. The concentrations of losartan and its active metabolite losartan acid were analyzed by combined reversed phase liquid chromatography and tandem mass spectrometry (LC-MS-MS) with negative ion electrospray ionization using a selected ion monitoring method. From the losartan and losartan acid plasma concentrations vs. time curves the following pharmacokinetic parameters were obtained: AUClast, AUC0-inf and Cmax. Results: the geometric mean and respective 90% confidence interval (CI) of Losartan / Cozaar® losartan percent ratios were 92.9% (82.2 - 105.0%) for Cmax, 99.0 (92.5 - 105.9%) for AUClast, and 99.1% (92.7 - 105.8%) for AUC0-M. Furthermore, the geometric mean and respective 90% confidence interval (CI) of Losartan / Cozaar® losartan acid percent ratios were 98.5% (91.5 - 106.0%) for Cmax, 97.9 (93.3 - 102.7%) for AUClast, and 98.1% (93.6 -102.9%) for AUC0 -inf. Since the 90% CI for Cmax, AUClast and AUC0-M were within the 80-125% interval proposed by the US-Food and Drug Administration. It was concluded that the potassium losartan immediate release 50 mg tablet was bioequivalent to the Cozaar® immediate release 50 mg tablet, according to both the rate and extent of absorption. Since there were no significant differences in the bioequivalence assessed by either losartan or losartan acid, future bioequivalence studies on losartan may be performed by quantifying losartan alone as the parent compound is more discriminative / Mestrado / Mestre em Farmacologia

A ifosfamida é um pró-fármaco que apresenta um átomo de fósforo quiral, disponível na clínica como mistura racêmica dos enantiômeros(+)-(R)-ifosfamida e (-)-(S)-ifosfamida para a utilização na quimioterapia. O objetivo do presente estudo foi o de avaliar a disposição cinética dos enantiômeros da ifosfamida em plasma de pacientes portadoras de câncer de colo do útero. As pacientes investigadas (n=6) receberam 2,5 g/m2 de ifosfamida racêmica administrada como infusão de 12 horas, sendo coletadas amostras de sangue imediatamente antes da administração e em 6, 10, 11, 12, 13, 14, 16, 18, 20 e 22 horas após a administração do fármaco. Os enantiômeros da ifosfamida foram quantificados por LC-MS/MS, sendo separados na coluna OD-R em aproximadamente 14 min empregando como fase móvel mistura de acetonitrila e água (20:80) adicionada de 0,2% de ácido fórmico. O método é linear no intervalo de 1-100 ?g de cada enantiômero/mL de plasma a partir de extrações de alíquotas de 25 ?L de plasma, compatíveis com a aplicação em farmacocinética de infusão de curta duração da ifosfamida em pacientes com câncer de colo do útero.A disposição cinética da ifosfamidaéenantiosseletiva, com observação de maiores valores de AUC (437,31 vs349,18 h.?g/mL) e menores valores de clearance(4,17 vs5,22 L/h) para o enantiômero(+)-(R)-ifosfamida. / The prodrugifosfamide has a chiral phosphorus atom, and is available clinically as a racemic mixture of the enantiomers (+)-(R)-ifosfamide and (-)-(S)-ifosfamide for use in chemotherapy. The aim of this study was to evaluate the kinetic disposition of the enantiomers of ifosfamide in plasma of patients with cancer of the cervix. The investigated patients (n = 6) received 2.5 g/m2 of racemic ifosfamide administered as infusion of 12 hours and blood samples were collected immediately before administration and at 6, 10, 11, 12, 13, 14, 16, 18, 20 and 22 hours after drug administration. The enantiomers of ifosfamide were quantified by LC-MS/MS and were separated in an OD-R column in about 14 min using as mobile phase a mixture of acetonitrile and water (20:80) plus 0.2% of formic acid. The method is linear within the range of 1-100 mg of each enantiomer/mL of plasma from extractions of 25 mL aliquots of plasma, suitable for the application in pharmacokinetics of short duration infusion of ifosfamide in patients with cervical cancer. The kineticdisposition of ifosfamide is enantioselective, with observation of higher values of AUC (437.31 vs 349.18 h.?g/mL) and lower values of clearance (4.17 vs 5.22 L/h) for the enantiomer (+)-(R)-ifosfamide.

Trombin är ett trypsinliknande serinproteas som har stor del i kroppens reglering av blodets fluiditet och koagulation genom att det klyver faktorer som slutligen leder till att blodet kan koagulera och fibrin bildas. Syftet med det här projektet har varit att syntetisera fragment som designats med datorgrafiska metoder på Astra Zeneca och sedan analysera fragmenten med affinitetskromatografi med trypsin immobiliserad på kiselgelspartiklar. I projektet har även ett nytt koncept prövats, nämligen att analysera reaktionsblandningarna direkt med hjälp av trypsinkolonnen utan att först isolera och rena föreningarna. De designade fragmenten har syntetiserats med standardmetoder, bl.a. har N,N’dicyklohexylkarbodiimid (DCC) använts. DCC är ett kopplingsreagens som kopplar ihop aminer med karboxylsyror genom skapande av en amidbindning, peptidbindning. Ibland då lite mer komplicerade peptider skall göras, kan aminoänden eller karboxyländen skyddas med en skyddsgrupp, för att dessa inte ska reagera under reaktionssteget och för att man ska få den peptiden man är ute efter. Vätskekromatografi-masspektrometri, LC-MS har använts för identifiering av reaktionblandningarna (substanserna). Resultaten visade att två av de framställda föreningarna retarderades på trypsinkolonnen, vilket innebär att de växelverkar med trypsin och att s.k. hits, träffar erhållits. Synteserna verkar ha gått bra, då LC-MS har visat att det är rätt produkt som finns i kolven. Projektet har visat att det går att designa fragment som man syntetiserar och sen analyserar med AFC-MS. AFC-MS har dessutom visat vara en lämplig metod för screening av svagt bindande fragment. / Through different, intricate mechanisms, the body regulates the coagulation and the fluidity of the blood. This is an important part of the hemostasis if for example bleeding occurs, or to provide the body with oxygen and nutrition. Thrombin is a trypsin like serine protease that plays an important role in this process since it is cleaving factors that eventually lead to coagulation of the blood and production of fibrin. The aim of this project has been to synthesize fragments that have been designed with computer graphical methods by Astra Zeneca and then to analyze the fragments with affinity chromatography that has trypsin immobilized on silica particles. The project also introduces a new concept i.e. to analyze reaction mixtures on the trypsin column without first isolating and purifying the compounds. The design fragments are synthesized by earlier reported standard methods. N, N'-dicyclohexylcarbodiimide (DCC) was used as coupling reagents to form amide or peptide bonds between carboxylic acids and amines. In some of the reactions the amino group or the carboxylic groups of the amino acid were protected, to prevent these from interfering in the reaction and avoid to formation of unwanted substances. After the reactions the protecting groups were removed in different ways. If it is attached to the amine as a Boc-group (the most common protecting group to protect amino groups) it would be removed with trifluoracetic acid, and if the carboxyl group was protected, the protecting group would be removed with catalytical hydrogenolysis, for example by adding sodium hydroxide. To analyze if the right product has been acquired, analyzes with liquid chromatography-masspectrometry has been performed. The results showed that two of the prepared fragments were retarded on the trypsin column meaning that they interact with trypsin i.e. hits were obtained. The results showed that the two fragments that were analyzed with the trypsin column did retard a bit, which implies that they interact with trypsin. The synthesis seems to have been successful since the liquid-chromatography has shown that the right product has been made. This project has proven that it is possible to design fragments with computer graphical methods before synthesizing and analyzing with AFC-MS. AFC-MS has also been shown to be a suitable method for screening of weak binding fragments.

No description available.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this study analytical methods using liquid chromatography coupled to mass spectrometry with atmospheric pressure chemical ionization (LC-APCI-MS) were developed for the determination of polycyclic aromatic hydrocarbons in asphalt fractions. Fourteen polycyclic aromatic hydrocarbons (PAHs) 7 nitrogenated derivatives (NHPAs) and 5 oxygenated derivatives (OHPAs) were determined. These compounds are characterized by having two or more condensed aromatic rings, they have mutagenic and carcinogenic activity, and are widely distributed as constituents of complex mixtures in many environments. APCI interface parameters were optimized in order to obtain the highest sensitivity for all compounds. The detection limits of the methods ranged from 0,5 to 346,5 μg L-1 -1 for PAHs, from 0.1 to 57.3 μgL-1 for NHPAs and 0.1 to 6.6 μgL-1 for OHPAs. The limits of quantification were in the range from 1.7 to 1550 μg L-1 for PAHs, from 4.6 to 191 μg L-1 for NHPAs and finally 0.3 to 8.9 μg L-1 for OHPAs. The analytical methods developed were applied to brazilian asphalt samples after their fractionation according to ASTM D4124 and Green method. The concentration of PAHs in this sample ranged from 0.86 to 647 mg kg-1, and NHPAs were 9.26 to 2146 mg kg-1, the OPAHs were not detected. / Neste trabalho, métodos analíticos utilizando cromatografia líquida acoplada à espectrometria de massas com ionização química a pressão atmosférica (LC-APCIMS), foram desenvolvidas para a determinação de hidrocarbonetos policíclicos aromáticos em frações do asfalto. Foram determinados 14 hidrocarbonetos policíclicos aromáticos (HPAs), 7 derivados nitrogenados (NHPAs) e 5 derivados oxigenados (OHPAs). Estes compostos caracterizam-se por possuírem dois ou mais anéis aromáticos condensados, atividade carcinogênica e mutagênica, e por estarem amplamente distribuídos como constituintes de misturas complexas em muitos ambientes. Os parâmetros da interface de ionização química a pressão atmosférica (APCI) foram otimizados com o objetivo de obter a maior sensibilidade possível para todos os compostos. Os limites de detecção dos métodos variaram de 0,5 a 346,5 μg L-1 para os HPAs, 0,1 a 57,3 μg L-1 para os NHPAs e 0,1 a 6,6 μg L-1 para os OHPAs. Já os limites de quantificação ficaram na faixa de 1,7 a 1550 μg L-1 para os HPAs, 4,6 a 191 μg L-1 para os NHPAs e por fim 0,3 a 8,9 μg L-1 para os OHPAs. Os métodos analíticos desenvolvidos foram aplicados em amostras de asfalto brasileiro, após seu fracionamento segundo a ASTM D4124 e o método de Green. As concentrações dos HPAs quantificados na amostra variaram de 0,86 a 647 mg Kg-1, a concentração de NHPAs foi de 9,26 a 2146 mg Kg-1 e a presença de OHPAs não foi detectada.

The concern for pharmaceutically active compounds (PhACs) as contaminants in the environment and the need to assess their environmental risk have greatly increased since the early nineties. Among PhACs, antibiotics and antiviral drugs are of important concern due to their role in growing antibiotic and antiviral drugs resistance among pathogenic bacteria and influenza viruses, respectively. Besides resistance issue, the compounds may upset sensitive ecosystems as they are designed to be highly bioactive. Clinically-important antibiotics are virtually ubiquitous contaminants in sewage water and surface water. Notably, recent emergence of novel influenza and use of anti-influenza drugs (specially Tamiflu®) during seasonal influenza、 influenza epidemics and for future pandemic are of emerging concern. Every year seasonal influenza epidemic causes tens of millions of respiratory illnesses and 250, 000 to 500, 000 deaths worldwide. WHO (World Health Organization) recommend the use of antiviral drug Tamiflu® during pandemic, as they are easy to use. Currently only Japan uses over eighty percent of Tamiflu® prescribed globally during common seasonal influenza. It is a fact that a huge amount of antiviral drugs and antibiotics ( for post infection cure of respiratory illness) will be used during an influenza pandemic and will arrive to sewage treatment plants (STPs).Unfortunately, these compounds behaviors are mostly unknown in both conventional and advanced STPs. The exposure of antiviral drug in the wild fowl gut and its implications for hastening the generation of antiviral-resistance in avian influenza viruses are also an emerging issue. The major objective of this thesis work was to investigate the occurrence of antibiotics and antiviral drugs in sewage treatment plants and their fate in different sewage treatment plants. The specific objectives were as follows: (a) to established appropriate analytical method for the selected antibiotics and antiviral drugs in sewage treatment plants, (b) to investigate the occurrence and removal of antibiotics and antiviral drugs in sewage treatment plants differ in technology and operation conditions; and (c) to predicts environmental concentration of the target compounds during a pandemics and appraisal of appropriate technology to reduce the risk associated with widespread use under pandemic conditions. In this study we selected twenty antibiotics: one beta-lactam: ampicillin; four macrolides: azithromycin, clarithromycin and roxithromycin; five quinolones: ciprofloxacin, enrofloxacin, levofloxacin, nalidixic acid and norfloxacin; two tetracycline: tetracycline and oxytetracycline; five sulfonamides: sulfadimethoxine, sulfadimizine, sulfamerazine, sulfam- ethoxazole and sulfamonomethoxine; and four others: lincomycin, novobiocin, salinomycin and trimethoprim. Oseltamivir Carboxylate (OC), the active metabolite of oseltamivir phosphate (Tamiflu®) and amantadine (AMN) were selected as antiviral drugs. This dissertation consists of nine chapters: Chapter I describe the background and objective of the study and chapter II represent a brief literature review. In Chapter III, analytical methods for selected antibiotics and antiviral drugs (for the first time) in water and wastewater were described. In Chapter IV, the occurrences and fate of antibiotics in sewage treatment plants were investigated in Japan and China. Clarithromycin was detected in the highest concentration in influent (1129 to 4820　ng/L), followed by azithromycin (160 to 1347　ng/L), levofloxacin (255 to 587　ng/L) and norfloxacin ( 155 to 486 ng/L) and sulfamethoxazole (159 to 176ng/L) in Japan. Ozonation as tertiary treatment of secondary effluent for wastewater reclamation provided significant elimination of antibiotics. Fifty present of the selected antibiotics were removed over eighty percent during ozonation. There was no elimination of antibiotics in dissolve phase during ultra filtration. From Chapter IV a hypothesis was drawn on antibiotics removal and its relation with longer sludge retention time (SRT) in STPs and in Chapter V the role of nitrifier in antibiotics removal was evaluated to verify the hypothesis established from Chapter IV. Nitrifying activated sludge (NAS) can biodegrade the tested antibiotics with different biodegradation rate between　2.74 to 9.95 L/gSS/d. Sulfamethoxazole and sulfamerazine degraded faster than trimethoprim, clarithromycin and enrofloxacin. In Chapter VI, occurrence of antiviral drugs in sewage water discharge and in river water in Japan was conducted during seasonal influenza epidemic and their fate in different sewage treatment facilities were evaluated in Chapter VII. This is the fist findings of antiviral (anti-influenza) drugs in the environment in the world and for the first time the removal mechanism in STPs was elucidated. Finally, it was observed that only primary and secondary treatment processes in STPs were not sufficient to remove these compounds significantly. Overall OC and AMN removal in STP with ozonation as tertiary treatment was 90% and 96% respectively. In ozonation batch experiment, Chapter VIII, ( feed ozone gas concentration 4.0mg/L, ozone gas flow rate 0.23L/min to maintain ozone feed rate of 0.6 mg/L/min), it was observed that AMN and OC concentration decreased linearly with time in all the experiments conducted and it can be, therefore, said that the degradation reactions follow pseudo first-order reaction. The k'O3 (pseudo first-order rate constant for O3) of AMN was 0.596/min (0.00993/sec), and OC was 0.524 /min (0.008725/sec) and over 99% removal within 10min. Chapter VIII described the predicted OC and antibiotics concentration in STPs influent, secondary effluent, after advance tertiary treatment (ozonation) and receiving water during a pandemic with three expected infection scenario ( according to US CDC FluAid model 2.0) in Kyoto city. Both antiviral drugs and antibiotics pose an environmental risk associated to there widespread use during a future pandemic. Ozonation as tertiary treatment can provide a technological solution to reduce the ecotoxicological effect of antibiotics and antiviral drugs uses during a pandemic. In a full scale STP, the antiviral drugs (OC and AMN) reduction were over 90% from secondary effluent after ozonation during seasonal influenza outbreak in Kyoto city in 2008/2009. Finally, (1) analytical methods for commonly used antibiotics and antiviral drugs in water sample was developed with an excellent precision and accuracies, (2) both antibiotics and antiviral drugs were detected in environmental sample, and their behavior in STPs were elucidated. Antivirals in this study were the first time findings in sewage water. This study will provide a surrogate for planning a pandemic preparedness action plan for sewage treatment pants for ecotoxicological risk management. / Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14931号 / 工博第3158号 / 新制||工||1474(附属図書館) / 27369 / UT51-2009-M845 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 伊藤 禎彦, 教授 藤井 滋穂 / 学位規則第4条第1項該当

Introduction: Nausea and vomiting are the most common and distressing side effects of chemotherapy because they negatively impact on quality of life and treatment compliance. Adequate control of nausea and vomiting in children receiving chemotherapy is imperative. Currently, the first-line drug for the prophylaxis and treatment of chemotherapy-induced nausea and vomiting (CINV) in paediatric patients is the serotonin (5HT3) receptor antagonist, ondansetron, administered intravenously. However, the parenteral route of administration of this drug is now being questioned as it is inconvenient for children and there is pressure to switch to an available oral formulation. The aim of this study was to evaluate the ease of administration, efficacy and cost-effectiveness of intravenous (IV) and oral tablet (OT) formulations of ondansetron in paediatric cancer patients receiving moderately emetogenic chemotherapy at the Steve Biko Academic Hospital in Pretoria, Gauteng (South Africa).Methods: It was an open-label, parallel, randomized trial. Thirty (30) patients scheduled to receive moderately emetogenic chemotherapy were recruited from the paediatric oncology department of the hospital. These patients were randomized to receive the same dose of either IV or OT ondansetron for the prophylaxis of CINV for one chemotherapy cycle. The efficacy of the agents was determined using a visual analogue scale (VAS) completed by the paediatric patients, which was compared to a one page questionnaire completed by the parents of the patients. Both questionnaires were completed at the end of chemotherapy (treatment period) as well as after a week without chemotherapy treatment (follow-up period). The patients’ plasma concentrations of ondansetron at four different time points were quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS). The ondansetron plasma concentrations obtained in the IV group were compared to those obtained in the OT group. The cost-effectiveness calculations included the direct costs of antiemetic prophylaxis and treatment, the use of any rescue medication and the length of hospital stay. Results: The VAS revealed that patients who were given antiemetic prophylaxis with OT ondansetron experienced less acute and delayed nausea than the patients in the IV ondansetron group; however, these differences were not statistically significant (p=0.538). Vomiting was similar in the two groups (p=1). There was a statistically significant difference between the patients and their parents in the perception of acute nausea (p=0.018), with parents overstating the level of acute nausea felt by their children. The plasma concentrations of ondansetron in patients on the IV formulation were higher than the ones in patients on the OT formulation at all the time points investigated. At 30 minutes post-dosing the mean plasma concentration of ondansetron in the IV group was significantly higher than in the OT group (p=0.0015), but the differences in plasma concentrations between the two groups from 2 hours were fairly comparable. The cost of antiemetic prophylaxis for IV ondansetron was significantly higher than the cost of antiemetic prophylaxis using the equivalent OT dose (p=0.0351). Conclusion: For the prevention of CINV, OT ondansetron, a 5HT3 receptor antagonist, proved to be an easy to use and cost-effective alternative to IV ondansetron in paediatric cancer patients receiving moderately emetogenic chemotherapy treatment. / Dissertation (MSc)--University of Pretoria / Pharmacology / unrestricted

A LLE-GC-MS method was developed to detect PPCPs in surface water samples from Big Cypress National Park, Everglades National Park and Biscayne National Park in South Florida. The most frequently found PPCPs were caffeine, DEET and triclosan with detected maximum concentration of 169 ng/L, 27.9 ng/L and 10.9 ng/L, respectively. The detection frequencies of hormones were less than PPCPs. Detected maximal concentrations of estrone, 17β-estradiol, coprostan-3-ol, coprostane and coprostan-3-one were 5.98 ng/L, 3.34 ng/L, 16.5 ng/L, 13.5 ng/L and 6.79 ng/L, respectively. An ASE-SPE-GC-MS method was developed and applied to the analysis of the sediment and soil area where reclaimed water was used for irrigation. Most analytes were below detection limits, even though some of analytes were detected in the reclaimed water at relatively high concentrations corroborating the fact that PPCPs do not significantly partition to mineral phases. An online SPE-HPLC-APPI-MS/MS method and an online SPE-HPLC-HESI-MS/MS method were developed to analyze reclaimed water and drinking water samples. In the reclaimed water study, reclaimed water samples were collected from the sprinkler for a year-long period at Florida International University Biscayne Bay Campus, where reclaimed water was reused for irrigation. Analysis results showed that several analytes were continuously detected in all reclaimed water samples. Coprostanol, bisphenol A and DEET’s maximum concentration exceeded 10 µg/L (ppb). The four most frequently detected compounds were diphenhydramine (100%), DEET (98%), atenolol (98%) and carbamazepine (96%). In the study of drinking water, 54 tap water samples were collected from the Miami-Dade area. The maximum concentrations of salicylic acid, ibuprofen and DEET were 521 ng/L, 301 ng/L and 290 ng/L, respectively. The three most frequently detected compounds were DEET (93%), carbamazepine (43%) and salicylic acid (37%), respectively. Because the source of drinking water in Miami-Dade County is the relatively pristine Biscayne aquifer, these findings suggest the presence of wastewater intrusions into the delivery system or the onset of direct influence of surface waters into the shallow aquifer.

Anatoxin-a (ANTX) is a neurotoxin produced by several freshwater cyanobacteria and has been implicated in the death of livestock and domestic animals from consumption of tainted surface waters. ANTX is unstable under normal conditions and is somewhat problematic to extract and study. Accelerated solvent extraction (ASE) combined with liquid chromatography-mass spectrometry (LC/MS) was used to develop an efficient extraction and analytical method for both ANTX and the more commonly encountered hepatotoxic microcystins produced by cyanobacteria. The effects of nitrogen supply on the cellular production and release of ANTX was investigated in Aphanizomenon issatschenkoi (Ussaczew) Proschkina-Lavrenko (Nostocales). In contrast to the predictions of the carbonnutrient balance hypothesis, the maximum production was observed under moderate N stress. In addition, steady state fugacity-based models were employed to investigate ANTX’s distribution and fate in freshwater ecosytems. ANTX was not found to be very persistent in aquatic ecosystems and did not appear to bioaccumulate in fish, at least not from the dissolved phase.

Many diseases are caused by proteins or peptides folding incorrectly and aggregating into fibrils or plaques, including Alzheimer’s disease, Parkinson's disease and type II diabetes. Amyloid formation in the human pancreas occurs via the aggregation of a 37 amino acid peptide called amylin or IAPP which is shown to be toxic to pancreatic β cells. Amylin (IAPP) aggregation initiates a large number of events, leading ultimately to cell death. However the exact cytotoxic action of human IAPP and also the underlying molecular events leading from amylin (IAPP) aggregation to β cell death is still unknown. The toxic effect of human amylin (IAPP) is thought to involve changes in the expression of several genes and proteins. Further transcriptional and proteomics studies in this field can therefore facilitate the identifications of new targets whose expression are affected by amylin (IAPP). These information could be further used to construct an integrated model of the signalling and regulatory pathways through which amylin (IAPP) interacts with cellular metabolism.To investigate the effects of amylin (IAPP) aggregation on the islets proteome in this study, rat Rin-5F cell line, reported as a model of pancreatic β cell, was used. MTT assay was initially performed to determine the effect of IAPP on the cell viability at different time points. The isolated proteins form the untreated and IAPP treated Rin-5F cells were then fractionated by off gel electrophoresis and analysed by quantitative label free LC- MS/MS approach.Label free quantification of IAPP treated Rin-5F cells has identified the altered expression of many proteins, some of which were previously suggested in the literature to be involved in the pathogenesis of type 2 diabetes. These proteins were map to several pathways (including glycolysis and proteasome) whose expressions were significantly affected upon amylin (IAPP) exposure. The IAPP responsive proteins were also structured into a well connected network. Some of the hub proteins identified in this network were greatly affected as the result of IAPP treatments of RIN-5F cells. Our data therefore revealed the effect of IAPP on several proteins and pathways that might be important in the pathogenesis of type 2 diabetes.