Hereditary Hemochromatosis (HH) is an inherited recessive autosomal disorder characterized by accumulation of excess iron. When iron binding proteins become saturated, concentrations of free, or non-transferrin-bound iron (NTBI) rise, a condition thought to be responsible for the adverse effects associated with HH. To investigate that disturbing iron homeostasis plays a role in free radical injury in HH, protein carbonyls were found to be 1-7 times higher in patients with HH than in controls, with the greatest increases being observed in untreated HH patients with high ferritin and >90% transferrin saturation with iron. An Unpaired t test revealed a P value of 0.0278 (P< 0.05), which is considered to be statistically significant. Our data showed a significant positive correlation (linear relationship) between the level of carbonyl content and ferritin concentration in plasma samples from patients with HH. In vitro oxidation of transferrin and ferritin standards with hydrogen peroxide and excess iron, followed by immobilized trypsin digestion (Poroszyme), high-resolution LC-MS/MS analysis (Q-TOF Ultima, Waters) and MS/MS data processing (PEAKS, Bioinformatics Solution), identified several tryptic peptides containing oxidized Met,Trp and His residues. Mapping of the oxidized ferritin residues showed them to be located on the inner face of each sub-unit, the face directed toward the ferritin core where iron is normally stored. Using the same methodology, oxidized residues were subsequently detected in ferritin and transferrin isolated from plasma samples of patients severely affected with HH. Comparing of MS/MS spectra of in vitro oxidized samples that have most fragment ion peaks in common with oxidized peptide MS/MS spectra from samples of patients with HH revealed a significant correlation between the two. These data show that elevated NTBI may be involved in oxidative modification of the iron binding proteins, ferritin and transferrin, and that such modifications may play a significant role in the pathophysiology of HH.

Clopidogrel is an antiplatelet substance that prevents blood coagulation in the arteries. It is an inactive pro drug that becomes activated after first-pass metabolism by the liver. The active metabolite of clopidogrel is 2-oxoclopidogrel, which is unstable therefore pharmacokinetic data is obtained by measuring the inactive metabolite clopidogrel acid in plasma. Clopidogrel is taken orally in tablet form. The aim of this project was to develop a LC-MS/MS method for quantification of clopidogrel and its metabolite in plasma.   The method has been developed by optimizing the sample preparation. Different extraction procedures and extraction columns were tested, for example, by changing the extraction column from a C8 silica sorbent to Oasis HLB (a polymer sorbent). Different internal standards were evaluated as a result of discovering the signal suppression of the previous internal standard clopidogrel acid.  Flupentixol was found to be the best candidate.

Alkylphenol polyethoxylates are one of the most importantclasses of nonionic surfactants. They are widely used in the household detergents and dyeing industry. Indeed, alkylphenols have been estimated that they are persistence organic pollutions which are not easily biodegraded by microorganisms and demonstrated as endocrine disruptors. Therefore alkylphenols regard as environmental hormones. The purpose in this research is developing the method which can be used for detection and quantification of alkylphenols and alkylphenol polyethoxylates in waters and sediments. LC-MS/MS was used as the analytical instrument which can analyze alkylphenols combined with long ethoxylate chain with improved sensitivity and selectivity. The extraction is liquid-liquid extraction. The mobile phase consisting of acetonitrile, water and methanol(43/14/43%, v/v/v) with 20mM ammonium acetate added was used for HPLC separation. The recoveries of alkylphenols and alkylphenol polyethoxylates from water and sediments were 83.0~95.1% and 84.8~94.6%. Decision limit(CC£\) and detection capability(CC£]) of water were 0.10~1.65 ng/L and 0.13~2.03 ng/L. CC£\ and CC£] of sediments were 0.05~0.95 ng/g and 0.06~1.18 ng/g.

In this study, a LC/MS/MS method for the determination of ampicillin antibiotic in fish muscle tissue was developed and accredited according to Commission Decision 2002/657/EC. The metabolism of ampicillin in tilapia was them studied in serum, liver and muscle. The homogenized fish tissue was first extracted with MeOH-H2O(4:1), C18 sorbent was added to remove lipids and impurities, the extract was then evaporated to dryness with a steam of nitrogen gas at 38 ¢XC. The residue was redissolved with H2O, filtered and analyzed by LC/MS/MS equipped with an Agilient HC-C18(5£gm, 150mm ¡Ñ4.6mm), the mobile phase A was 10mM ammonium acetate containing 0.1% formic acid, while the mobile phase B was methanol. The determination of ampicillin was performed with electrospray ionization-tandem mass spectrometry in positive mode using multiple reation monitoring(MRM) for detection. Average recoveries were 81¡V86%, the limit of detection was 6.00 £gg kg-1¡Adecision limit(CC£\) of ampicillin in fish muscle sample was 63.65 ¡Ó 7.99 £gg kg-1. In the metabolism study, the oral administered dose to talipia was 20 mg/kg¡DBW. The maximum concentration of ampicillin in each tissues was obserned at 0.5 hour after oral administration, the maximum concentration in serum, liver and muscle was 27.53 mg L-1, 66.75 mg kg-1 and 1.33 mg kg-1, respectively. The concentration of ampicillin in muscle was 0.04 mg kg-1 24 hours after oral administration, which is lower than the 0.05 mg kg-1 MRL value of European Union resolutions. No residual ampicillin was detected in tilapia 48 hours after oral treatment, which conformed to the drug regulations for aquaculture ainmals in Taiwan.

The purpose of this research is that investigate the effects of time and concentration of exposure for the accumulation and depletion of malachite green and leucomalachite green in tilapia by pharmacokinetics. LC-MS/MS was used as the analytical instrument in this research, and the detection limit of malachite green and leucomalachite green is 0.51 ppb and 0.48 ppb. The results show that malachite green is unstable at high temperature. Addition of TMPD into the standard can stabilize malachite green. The malachite green in exposure water is easy to adhere to the fiberglass tub and cause the decreases of concentration of malachite green in water. The concentrations of malachite green and leucomalachite green in tilapia are positive related to the time and concentration of exposure. In experiments of exposure of malachite green, the highest concentration of malachite green occurs in liver, accumulation rate constant is 21.62 h-1. Liver is also the major organ for transforming malachite green into leucomalachite green, the net leucomalachite green accumulation rate constant is 213.67 h-1. In the period of water bath, Gill is the fastest organ for eliminating malachite green and leucomalachite green, the elimination rate constant is 0.7799 h-1 and 0.4658 h-1; the leucomalachite green concentration in fat is still increase until 6h of water bath.

The study felld into three sections. The first section that a liquid chromatography method with fluorescence detection was developed for simultaneous determination of 11 quinolones (QNs; marbofloxacin, norfloxacin, ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin, difloxacin, oxolinic acid, nalidixic acid and flumequine) in chicken, pork, fish and shrimp. The analytes were extracted with 0.3% metaphosphoric acid: acetonitrile (1:1, v/v), followed by a HLB cartridge clean-up procedure. The HPLC separation was carried out on a symmetry column C18 (250 mm x 4.5 mm i.d., 5 £gm) with linear gradient elution of 0.1% formic acid: acetonitrile as mobile phase and programmable fluorescence detection. The method was validated by spiking blank animals tissues at three different levels (25, 50 and 250 ng/g; except 6.25, 12.5 and 62.5 ng/g for DAN) and linearity, detection limit, quantification limit, precision and accuracy were checked. Mean recoveries of 11 QNs from edible animal tissues were 71.7-105.3%. The limits of quantification in different muscle tissues ranged from 5.0 to 28.0 ng/g. The results showed it was simple, rapid, sensitive and suitable for routine test. The second section that a LC-ESI-MS/MS method was developed for determining 18 (fluoro)quinolone (QNs) residues in milk, chicken, pork, fish and shrimp. This method is capable of screening and confirming the presence of 12 amphoteric QNs (marbofloxacin, norfloxacin, enrofloxacin, ciprofloxacin, desethylene ciprofloxacin, lomefloxacin, danofloxacin, sarfloxacin, difloxacin, ofloxacin, orbifloxacin and enoxacin) and 6 acidic QNs (oxolinic acid, nalidixic acid, flumequine, cinoxacin, piromidic acid and pipemidic acid). The drugs were extracted from matrix using acetonitrile with 1% formic acid, diluted in 10% acetonitrile and defatted by extraction with hexane. The LC separation was conducted on a XDB C8 (150 x 4.6 mm, 5£gm) column with gradient elution of 20 mM ammonium formate with 0.1% formic acid¡Vacetonitrile as the mobile phase. Mass spectral acquisition was completed in the positive ion mode by applying multiple reaction mode (MRM). The decision limit (CC£\) and detection capability (CC£]) stated in the Decision No. 2002/657/EC and the ISO standard No.11843, has been calculated in the case of the nonauthorized substance. The values of CC£\ ranged from 0.18 to 0.68 ng/g and CC£] ranged from 0.24 to 0.96 ng/g under specified conditions. The third section that the pharmacokinetics of ENR and its active metabolite (CIP and des-CIP) were estimated in tilapia after intravenous (i.v.) and oral (p.o.) administration of a single dose of 2.5 and 10 mg/kg body weigh, respectively. At prefixed time points, from 0.25 h to 7 days after administration, whole blood and main tissue (liver, kidney, bile and muscle) from 4 individuals in each were collected. The concentration of ENR and its active metabolites in the main tissue were simultaneously detected by LC/MS/MS method. Limited of quantitation (LOQ) of this method were 0.01£gg/g. Pharmacokinetic parameters from both routes were described to have a two- compartment open model with first-order elimination. After i.v. administration, the area under the drug concentration-time (AUC), elimination half-life (t1/2£]), maximum plasma concentration (Cmax ), total body clearance (Cltot) and apparent volume of distribution at steady-state (Vss) of ENR were 109.6 ¡Ó 31.33 £gg.h/mL, 55.17 ¡Ó 22.84 h, 4.70 ¡Ó 0.36 £gg/mL, 14.82 ¡Ó 4.24 L/h/kg, 1105 ¡Ó 223.40 L/kg ,respectively. After oral administration, the AUC , t1/2£], Tmax , Cmax of ENR were 599.42 ¡Ó 76.19£gg.h/mL , 75.95 ¡Ó 12.94 h, 0.601¡Ó0.06h, 9.75 ¡Ó 0.46£gg/mL, respectively. After p.o. administration, CIP could be detected in liver, kidney and bile. Regarding des-CIP, the main active metabolite of CIP, could be detected in 120¡ã168 h bile among tissue. ENR and CIP had significance enterohepatic cycle in Tilapia and easily accumulated in bile. It seems reasonable to explain the phenomenon of ENR and CIP maintenance of high concentration in blood and muscle during the test time.

Résumé: Les dommages à la cytosine, spontanés et induits par des oxydants, sont probablement la principale cause des transitions GC vers AT, la mutation du génome la plus commune chez les organismes aérobiques. Ces dommages sont impliqués dans le processus de mutagenèse, dans le vieillissement et dans le cancer. Les dommages à la cytosine par les oxydants et les radicaux libres sont nombreux et ont été découverts et étudiés dans les monomères de cytosines et dans de courts oligonucléotides. Dans cette étude, nous avons développé une méthode d'analyse par HPLC-MS/MS des plus importants produits d'oxydation de la cytosine dans l'ADN. Cette méthode permet l'analyse de la formation de 5-hydroxy-2'-désoxycytidine (5-OH-dC), de 5,6-dihydroxy-5,6-dihydro-2'-désoxyuridine (dUg), de 1-(2-désoxyribose)-5-hydroxyhydantoïne (HdU) et de 3-(2-désoxyribose)-1-carbamoy1-4,5-dihydroxy-2-oxo-imidazolidine (C422-dC) lors d'irradiation aux rayons gamma par réaction de type fenton et par ozonolyse. Les résultats de l'irradiation de l'ADN aux rayons gamma (en modifications/106bases/Gy) sont de 1.62 pour la 5-OH-dC, de 1.48 pour le dUg, de 7.43 pour la HdU et de 1.38 pour la C422-dC. La réaction de type fenton avec le cuivre donne une formation de dommages environ 25 fois plus grande qu'avec le fer et les deux types (cuivre et fer) donnent des ratios de produits semblables à ceux par les rayons gamma avec une augmentation de la 5- OH-dC et une diminution de la HdU. L'exposition .de l'ADN à l'ozone donne une très grande formation de la HdU et une faible formation des autres produits d'oxydation.//Abstract: The damages to cytosine, spontaneous and inducted by oxidants, are probably the principal cause of the GC to AT transition, the most important mutation of the genome for the aerobic organisms. Those damages are involved in the process of mutagenesis, aging and cancer. The damages to cytosine by oxidants and fre radicals are numerous and have been discovered and studied in monomers of cytosine and in short oligonucleotides. In this study, we have developed a analysis method of the most important oxidation products of cytosine in DNA by HPLC-MS/MS. This method allows the analysis of the formation of 5-hydroxy-2'-deoxycytidine (5-OH-dC), de 5,6-dihydroxy-5,6-dihydro-2'-desxyuridine (dUg), de 1-(2-deoxyribose)-5-hydroxyhydantoin (HdU) et de 3-(2-deoxyribose)- 1-carbamoyl-4,5-dihydroxy-2-oxo-imidazolidine (C422-dC) after irradiation by gamma rays, by fenton type reaction and ozonolysis. The results of the irradiation of DNA by gamma rays (in modifications10[indice supérieur 6] bases/Gy) are of 1.62 for 5-OH-dC, of 1.48 for dUg, of 7.43 for HdU and of 1.38 for C422-dC. The fenton type reaction with copper gives a formation of damages about 25 times higher than with ferrous and both kind gives a ratio of formation similar to the the ones by gamma rays with a increase of 5-OH-dC and a decrease of HdU. The exposition of DNA to ozone gives a strong formation of HdU and a small formation of the other modifications. [symboles non conformes]

The study of leptospiral pathogenesis is hampered by the lack of efficient mutagenesis methodologies. Thus research has focused on alternative approaches including genome sequencing, comparative genomics, transcriptomics and proteomics. In this thesis a comparative proteomic approach was used to identify leptospiral proteins with a potential role in the leptospiral infection process. Identification of proteins was followed by characterization of target proteins with potential roles in the infection process and ultimately led to the identification of a novel leptospiral virulence factor. Specifically, comparative proteomics using isobaric tags for relative and absolute quantitation complemented with two-dimensional gel electrophoresis were used for mass spectrometry-based protein identification and quantitation. These methodologies were utilised to identify and quantitate leptospiral proteins altered in expression in response to growth media limited in iron supply and/or supplemented with serum. These conditions were designed to mimic a subset of variables encountered by the bacteria within the host. These experiments led to the identification of five proteins with potentially novel roles in the leptospiral infection process. One of these proteins was further characterized as a periplasmic catalase, KatE. Using insertion mutagenesis it was demonstrated that KatE enhances extracellular H2O2 resistance and is required for virulence in guinea pigs and hamsters. Proteomic analyses also led to the identification of glutamic acid methylation of a protein that was further characterised to be surface exposed and expressed during leptospiral colonization of hamster liver and kidneys. This was the first description of glutamic acid methylation of a surface exposed protein in Leptospira. / Graduate

Orientador: Pedro de Magalhães Padilha / Resumo: Devido a sua grande concentração de nutrientes, tais como proteínas, vitaminas e minerais, o peixe é considerado um dos alimentos mais saudáveis que se pode encontrar na natureza. No entanto, a ingestão de peixes é considerada a forma predominante de via de exposição do ser humano ao mercúrio (Hg), principalmente para as populações que vivem às margens dos rios, onde o peixe constitui a principal fonte de proteína. Na tentativa de elucidar os mecanismos de toxicidade das espécies mercuriais, o teor desse metal tem sido estudado intensamente pela comunidade científica nas últimas décadas em amostras de solo, sedimentos, humanos e peixes na Amazônia brasileira. Sabe-se que as espécies mercuriais bioacumuladas nos tecidos dos seres vivos ligam-se a metaloproteínas, e quando há uma concentração alta de metal tóxico nos organismos, esses passam a expressar proteínas de defesa, denominadas metalotioneínas (MTs) responsáveis pelo transporte e eliminação de metais tóxicos. Apesar de estudos mostrarem o aumento das metalotioneínas em animais expostos a metais potencialmente tóxicos, essas proteínas não foram caracterizadas para confirmação de sua veridicidade, são analisadas por métodos indiretos, esse fato leva a necessidade de técnicas mais precisas na identificação de metalotioneínas. Levando em consideração o exposto esse estudo teve como objetivo otimizar métodos de quantificação de mercúrio e técnica de eletroforese para identificação de possíveis metalotioneínas biomarcadoras d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to its high concentration of nutrients, such as proteins, vitamins and minerals, fish is considered one of the healthiest foods that one can find in nature. However, fish intake is considered to be the predominant human exposure pathway to mercury (Hg), especially for populations living along riverbanks where fish are the main source of protein. In the attempt to elucidate the toxicity mechanisms of mercurial species, the content of this metal has been intensively studied by the scientific community in recent decades in soil, sediment, human and fish samples in the Brazilian Amazon. It is known that mercurial species bioaccumulated in the tissues of living beings bind to metalloproteins, and when there is a high concentration of toxic metal in organisms, they begin to express defense proteins, called metallothioneins (MTs) responsible for the transport and elimination of Toxic metals. Although studies have shown the increase of metallothioneins in animals exposed to potentially toxic metals, these proteins have not been characterized to confirm their veridicity, are analyzed by indirect methods, this fact leads to the need for more precise techniques in the identification of metallothioneins. Taking into account the above, this study aimed to optimize mercury quantification methods and electrophoresis technique for identification of possible mercury biomarkers metallothionein in muscular and hepatic tissue of fish of economic interest, Tucunaré (Cichla spp.), Filhote (Bra... (Complete abstract click electronic access below) / Doutor

Orientador: Pedro de Magalhães Padilha / Resumo: O peixe é uma importante fonte de proteínas de alto valor biológico, vitaminas e minerais. Porém, este alimento é também uma das principais vias de exposição humana a contaminantes tóxicos como o metilmercúrio (MeHg). Assim a sua acumulação no peixe pode predispor sérios riscos para a saúde humana. As altas concentrações de mercúrio encontrados em solo, sedimentos, peixes e humanos na Amazônia brasileira têm sido estudados intensamente pela comunidade científica nas últimas décadas, procurando-se elucidar os mecanismos de toxicidade das espécies mercuriais. As espécies mercuriais ligam-se preferencialmente às proteínas. Podendo significar que a fração biodisponível das espécies mercuriais nas diferentes espécies de peixes pode ser dependente da forma como estas estão ligadas a essas proteínas. Portanto esta proposta de trabalho buscou otimizar procedimentos eletroforéticos por 2D-PAGE para fracionamento e identificação de proteínas responsáveis pelo transporte de mercúrio em amostras de tecido muscular e hepático de peixes coletados no reservatório da Usina Hidrelétrica de Jirau – no rio Madeira; utilizando o método de espectrometria de absorção atômica em forno de grafite (GFAAS), para determinação de mercúrio nos tecidos e spots proteicos obtidos; avaliou o estresse oxidativo dos peixes contaminados com mercúrio por meio das atividades das enzimas catalase (CAT), glutationa peroxidase (GSH-Px) e superóxido dismutase (SOD), bem como das concentrações de hidroperóxido de lipí... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor