Für die Therapie maligner intranasaler Neoplasien beim Hund existieren nur mäßig be-friedigende Behandlungsstrategien. Als Therapiemodalität der Wahl wird die Radiothe-rapie angesehen, die gegenwärtig v.a. in Form einer perkutanen Bestrahlung (Telethe-rapie) mit aufwendigen, bis zu 20 Fraktionen umfassenden Protokollen kurativer Intenti-on angewendet wird. Die erreichbaren Überlebenszeiten sind meist limitiert durch das Auftreten eines Rezidivs des Nasentumors innerhalb des Bestrahlungsfeldes, sodass eine Erhöhung der applizierten Gesamtdosis nötig erscheint. Dies ist jedoch im Rahmen einer Teletherapie aufgrund nicht vertretbarer akuter Nebenwirkungen nicht möglich. Alternativ steht die Brachytherapie zur Verfügung, die aufgrund ihrer physikalischen Charakteristika zur besseren Schonung des umliegenden Normalgewebes beiträgt. Ge-genwärtig existieren keine anderen Untersuchungen zur Anwendung der fraktionierten High-Dose-Rate-Brachytherapie bei Nasentumoren des Hundes. Ziel dieser Studie war es daher, die Durchführbarkeit dieser Therapiemodalität beim Hund erstmals zu unter-suchen und die akuten und chronischen Nebenwirkungen sowie die erzielbare progres-sionsfreie Zeit und die Überlebenszeit zu dokumentieren. Im Zeitraum von 2001 bis 2007 gingen 18 Hunde in die Studie ein. Das diagnostische Vorgehen beinhaltete neben einer klinischen Untersuchung und der Röntgenuntersu-chung von Nase und Thorax auch die kernspintomographische Beurteilung der Nasen-höhlen und eine nachfolgende Rhinoskopie inklusive Biopsie. Die Therapie bestand aus zwei wöchentlichen Fraktionen, bei denen in Vollnarkose über einen in der Nasenhöhle applizierten Katheter mithilfe des Radioisotops 192Iridium jeweils 5 Gy appliziert wurden. Die damit über vier Wochen erreichte Gesamtdosis lag bei 40 Gy, und entsprach damit der biologischen Effizienz einer perkutan applizierten konventionell fraktionierten Ge-samtdosis von circa 60 Gy. Im Anschluss an die Therapie wurden die Hunde monatlich klinisch untersucht und die auftretenden Nebenwirkungen anhand des Radiation Morbi-dity Scores der VRTOG beschrieben. Es wurden außerdem weiterführende Untersu-chungen in Form von MRT, Rhinoskopie und Biopsie durchgeführt. Die aufgetretenen Nebenwirkungen waren mit denen in der Literatur nach Teletherapie beschriebenen vergleichbar, beziehungsweise fielen im Bereich von Augen und Maulschleimhaut ge-ringer aus. Nebenwirkungen im Bereich der Haut traten in Form von Alopezie, Hyper-pigmentation oder Leukotrichie auf. Im Bereich der Nasenschleimhaut zeigten fast alle Hunde eine leichte chronische Rhinitis. Als problematische Nebenwirkungen traten bei drei Patienten Osteoradionekrosen auf, die einer aufwendigeren chirurgischen Versor-gung bedurften. Die mediane progressionsfreie Zeit lag bei 13 Monaten, die mediane Überlebenszeit bei 17 Monaten. Die Adenokarzinome wiesen die längste Überlebens-zeit auf, dies war jedoch aufgrund der insgesamt kleinen Patientenzahl nicht signifikant. Ein Zusammenhang zwischen dem Tumorstadium und der progessionsfreien Zeit oder Überlebenszeit bestand nicht. Bei dem beschriebenen Protokoll handelt es sich um eine unter klinischen Bedingungen praktikable Therapieform, die mit ihren insgesamt acht Fraktionen für Besitzer und Tier wesentlich weniger belastend ist als teletherapeutische kurative Protokolle mit 12-20 Fraktionen. Gleichzeitig gelingt es, eine Gesamtdosis von verhältnismäßig hoher biolo-gischer Effizienz zu applizieren, ohne jedoch stärkere Nebenwirkungen in Kauf nehmen zu müssen. Im Bereich von Auge und Maulschleimhaut sind die Nebenwirkungen sogar geringer. Bei einem kleinen Teil der Patienten treten jedoch auch hier, ebenso wie nach teletherapeutischen Protokollen, problematische chronische Nebenwirkungen auf, die die Lebensqualität der betroffenen Tiere beeinträchtigen und die einer aufwendigeren Therapie zwingend bedürfen. Die mit diesem Protokoll erreichten Remissions- und Ü-berlebenszeiten sind mit denen aus der Literatur vergleichbar bis tendenziell besser. Aufgrund der oben genannten Vorteile erscheint die vorgestellte Therapie daher als Al-ternative zu Teletherapie bei der Behandlung kaniner Nasentumoren durchaus geeig-net. Weitere Studien mit größeren Patientenzahlen unter Einbeziehung einer anders therapierten Kontrollgruppe sind jedoch notwendig

Le cetuximab (CTX) est un anticorps monoclonal anti-EGFR indiqué dans les cancers ORL dont les modalités de prescription pourraient être améliorées. Après chimiothérapie d’induction (étude Tremplin), en comparaison au cisplatine, il était moins toxique mais sans améliorer la préservation laryngée. À la première injection, le CTX peut déclencher un choc anaphylactique lié à la préexistence d’IgE anti-αGal. Des tests prédictifs détectant ces IgE ont été développés et réalisés chez 41 patients avec une sensibilité et une valeur prédictive négative de 100%. La relation entre concentrations sériques et efficacité/toxicité a été étudiée chez 34 patients. La pharmacocinétique a été décrite à l’aide d’un modèle combinant des mécanismes d’élimination non saturable (CL) et saturable (k0). La clairance globale du CTX, reflet de l’exposition des patients, était reliée aux survies sans progression et globale (SG). Le grade de radiodermite était associé à la SG. Une simulation pharmacocinétique suggère, qu’en comparaison à l’injection standard de CTX, une injection toutes les trois semaines entrainera des AUC proches mais des concentrations résiduelles différentes. / Cetuximab (CTX) is an anti-EGFR monoclonal antibody approved in head and neck cancer, which prescription modalities may be improved. After induction chemotherapy (Tremplin study), compared to cisplatin, CTX was less toxic but did not improve larynx preservation. During first infusion, CTX can induce an anaphylaxis reaction due to the presence of preexisting anti-αGal IgE. Predictive assays detecting these IgE were developed and tested in 41 patients, with sensitivity and negative predictive values of 100%. Relationship between serum concentrations and efficacy/toxicity was studied in 34 patients. CTX pharmacokinetics was described using a model combining non-saturable (CL) and saturable (k0) eliminations. Global clearance, which reflects patient exposure, was related to progression free and overall (OS) survivals. Severe radiation dermatitis was also associated with OS. A pharmacokinetic simulation suggests that, in comparison to standard CTX infusion, an infusion every three weeks will lead to similar AUC but to different residual concentrations.

Les anticorps monoclonaux ont révolutionné le traitement de nombreuses pathologies. Cependant, leur pharmacocinétique (PK) et l’influence de leur concentration sur la réponse clinique restent mal connues. Nous avons étudié les sources de variabilité interindividuelle de la PK du cetuximab, un anticorps anti- EGFR, ainsi que l’influence de l’exposition à cet anticorps sur la réponse. Nous avons validé une méthode ELISA de dosage du cetuximab. Dans un modèle murin, nous avons étudié l’absorption pulmonaire du cetuximab. Nous avons étudié la PK du cetuximab chez un patient hémodialysé. Nous avons décrit la PK du cetuximab chez des patients traités pour cancer colorectal métastatique, à l’aide d’un modèle combinant des éliminations d’ordre 0 et 1. Enfin, nous avons identifié la clairance globale du cetuximab, paramètre pouvant être estimé précocement par la concentration résiduelle à J14, comme un facteur influençant la survie sans progression des patients. Nos travaux montrent qu’une description de la PK d’un anticorps par approche compartimentale permet d’identifier les sources de variabilité et d’étudier l’impact de la PK sur la réponse clinique. / Monoclonal antibodies have profoundly modified the treatment of many diseases. However, their pharmacokinetics (PK) and the influence of their concentrations on the clinical response are poorly known. We studied the sources of the interindividual variability of PK of cetuximab, an anti-EGFR, and the influence of the exposure to this antibody on the response. We validated an ELISA technique to measure cetuximab concentrations. We studied the pulmonary absorption of cetuximab in a murine model. We studied cetuximab PK in a hemodialysed patient. In metastatic colorectal cancer patients, we described cetuximab PK with the help of a model combining zero- and first-order eliminations. Finally, we identified the global clearance of cetuximab, a parameter which can be estimated by residual concentration on day 14, as a factor influencing progression-free survival of the patients. Our work shows that the description of the PK of an antibody by compartmental approach allows to identify sources of variability and to study the impact of PK on the clinical response.

Abstract Fluoroscopically guided procedures are currently an area of special concern in relation to radiation protection, as they may produce a high radiation dose to patients and increase the risk of skin injury. ERCP is a gastrointestinal procedure used as a gold standard in the treatment of pancreatobiliary disorders. It is performed under endoscopic and fluoroscopic guidance. Recently, both the number and the complexity with associated increased technical difficulty of therapeutic ERCP procedures have significantly increased. The present study aimed to assess the medical use of radiation in ERCP, with special emphasis on optimisation of radiation protection of patients. For this purpose, the level of patient radiation exposure during ERCP was evaluated by registering the radiation dose indices in Finnish hospitals. The entrance surface dose was measured by thermoluminescent dosimeters and the effective dose was estimated using conversion coefficients. For dose optimisation and for quality assurance, the local diagnostic reference levels (DRL) for ERCP were established and reviewed after five years. A single centre prospective analysis was conducted to identify patient-, procedure- and operator-related factors affecting dose area product (DAP) and fluoroscopy time (FT). The results showed a large variation of dose indices in overall, as among participating hospitals due to differences in patient characteristics, operator, equipment and procedural complexity. The risk of radiation-induced skin injury and the lifetime cancer risk seems to be reasonably low, indicating ERCP to be a low-dose study. Local DRL is an effective tool in the optimisation process, as a certain degree of dose reduction was achieved during the years. Multiple factors were found to affect DAP and FT in ERCP. The awareness of these factors may help to predict possible prolonged procedures that cause a higher radiation dose to the patient and thus facilitate the use of appropriate precautions. / Tiivistelmä Säteilysuojelun näkökulmasta läpivalaisuohjauksessa tehtävät toimenpiteet ovat erityisen huolen aiheena, koska ne voivat aiheuttaa potilaille suuria säteilyannoksia ja siten lisätä ihovaurion riskiä. ERCP on ruoansulatuskanavan endoskopiatoimenpide, jota käytetään haima- ja sappitiesairauksien hoidossa kultaisena standardina. ERCP suoritetaan duodenoskoopilla läpivalaisukontrollissa. Viime vuosina ERCP toimenpiteiden määrät ja toimenpiteiden monimutkaisuus ovat kasvaneet merkittävästi lisääntyneen teknisen haastavuuden vuoksi. Tutkimuksen tarkoituksena oli arvioida säteilyn lääketieteellistä käyttöä ERCP:ssa, kiinnittäen eritystä huomiota potilaan säteilysuojelun optimointiin. Potilaan säteilyaltistuksen tasoa ERCP:ssa arvioitiin keräämällä potilasannoksia suomalaisista sairaaloista, pinta-annokset mitattiin termoloistedosimetreilla ja efektiivinen annos laskettiin muuntokertoimilla. Säteilyaltistuksen optimointi- ja laadunvalvonnan työkaluksi ERCP:lle asetettiin paikalliset vertailutasot ja ne tarkistettiin 5 vuoden kuluttua. Potilaaseen, toimenpiteeseen ja toimenpiteen suorittajaan liittyvät tekijät, jotka vaikuttavat annoksen ja pinta-alan tuloon (DAP) sekä läpivalaisuaikaan, selvitettiin retrospektiivisesti yhdessä sairaalassa. Tutkimuksen tulokset osoittivat, että potilaan säteilyannoksissa oli suurta vaihtelua niin yleisesti, kuin osallistuvien sairaaloiden välillä. Vaihtelu johtui potilaan ominaisuuksista, erilaisista läpivalaisulaitteista, toimenpiteen suorittajista ja ERCP toimenpiteiden vaikeusasteesta. Säteilyn aiheuttaman ihovaurion riski ja elinikäinen syöpäriski näyttäisi tulosten perusteella olevan kohtuullisen alhainen, mikä osoittaa, että ERCP on matala-annostutkimus. Paikallinen vertailutaso osoittautui tehokkaaksi optimointityökaluksi, sillä annostason lasku ERCP:ssa saavutettiin vuosien kuluessa. Useiden tekijöiden todettiin vaikuttavan DAP:n ja läpivalaisuaikaan ERCP:ssa. Näiden tekijöiden tiedostaminen voi auttaa tunnistamaan etukäteen ne haastavat ERCP toimenpiteet, jotka voivat aiheuttaa suuria säteilyannoksia potilaille, ja siten mahdollistaa niihin varautumisen.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-08-08T21:28:55Z No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-08-17T22:39:03Z (GMT) No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-08-17T22:41:07Z (GMT) No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) / Made available in DSpace on 2017-08-17T22:41:14Z (GMT). No. of bitstreams: 1 EdigleyceLC_DISSERT.pdf: 1495589 bytes, checksum: 331e814fbf35fd0903ce95ef191653df (MD5) Previous issue date: 2015-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Aspidosperma pyrifolium Mart species. it is used in feed for farm ani-mals. However, there are few studies on the toxicity of this plant. This study aimed to iden-tify the existence of toxic effect, cytotoxic and mutagenic leaves of A. pyrifolium the test system Allium cepa and mice. It was made growth analysis of roots, inhibition relative and mitotic index with the Allium cepa test. For the LD50 they were used of groups mice were observed for 14 days to determine the number of dead and surviving animals. For the mi-cronucleus test and binucleated cells was done extracting bone marrow of animals. Bioas-says performed with the Allium cepa revealed that the aqueous extract of dried leaves showed no toxic effects, however, stimulated cell division in a concentration of 50 mg/L, is indicative of formation of tumor cells. The fresh leaves were toxic at the concentration of 300 mg/L and had a effect toxic sublethal on concentration of 5 mg/L.. In mice, the median lethal dose was 750.63 mg/kg with the aqueous extract of fresh leaves, and lethal concen-trations tested from the concentration 900 mg/kg in males and females. The evaluated ani-mals showed behavioral changes in the nervous system and change in average total weight. The concentrations tested indicated are not mutagenic or not cytotoxic in the overall analy-sis of micronucleus frequency and binucleated cells, respectively. But, this work provides data toxicity; cytotoxicity and mutagenicity still have not investigated for the species A. pyrifolium / A espécie Aspidosperma pyrifolium Mart. é utilizada na alimentação por animais de produção. No entanto, são escassos os estudos sobre a toxicidade dessa planta. Este trabalho objetivou identificar a existência de efeito tóxico, citotóxico e mutagênico de folhas de A. pyrifolium no sistema teste Allium cepa e em camundongos. Foi feita a análise de crescimento de raízes, inibição relativa e índice mitótico com o teste Allium cepa. Para a DL50 foram utilizados grupos de camundongos, observados por 14 dias para determinar a quantidade de mortos, doentes e sobreviventes. Para o teste de micronúcleo e células binucleadas foi feita a extração da medula óssea dos animais. Os bioensaios com o Allium cepa realizados revelaram que o extrato aquoso das folhas secas não mostrou efeito tóxico, contudo, estimulou a divisão celular na concentração de 50 mg/L, sendo indicativo de formação de células tumorais. As folhas frescas foram tóxicas na concentração de 300 mg/L e teve efeito tóxico subletal na concentração de 5 mg/L. Nos camundongos, a dose letal mediana foi de 750,63 mg/Kg com o extrato aquoso de folhas frescas, sendo letal nas concentrações testadas a partir da concentração de 900 mg/Kg em machos e fêmeas. Os animais avaliados apresentaram alterações comportamentais no sistema nervoso e alteração no peso médio total. As concentrações testadas indicaram não serem mutagênicas e nem citotóxicas na análise geral das frequências de micronúcleo e células binucleadas, respectivamente. Mas, este trabalho fornece dados de toxicidade, citotoxicidade e mutagenicidade ainda não investigados para a espécie A. pyrifolium / 2017-08-08

Orientador: Vania dos Santos Nunes Nogueira / Abstract: Although being controversial, some services use Whole Body Imaging (WBI) with 131I prior to the ablative dose with this radiopharmaceutical in the treatment of differentiated thyroid cancers (DTC). Proponents of this approach argue for a better optimization of the ablative dose, and opponents argue that this WBI could lead to the "stunning effect" characterized by reduced tissue uptake of 131I in ablative dose treatment, thereby compromising treatment and prognosis of these individuals. Objective: To evaluate whether WBI with 131I, ablative pre-dose, interferes with the efficacy of the therapeutic dose of iodine as remission of the disease after total or near total thyroidectomy in individuals with DTC. Methodology: A systematic review of the literature was conducted in which randomized, non-randomized and observational studies were included in which the patients were in the late postoperative period of total or subtotal thyroidectomy due to one of the DCT and were assigned the diagnostic WBI with I131 before the ablative dose (intervention) or they performed WBI with 123I before the ablative dose, or non-performance of the diagnostic WBI (directly ablative dose with 131I) (control). The primary outcome was disease remission assessed by the ablative success rate at least six months after follow-up. Results: After performing the searches in the following electronic databases Embase (1980-25/04/2017), Pubmed (1966-25/04/2017), CENTRAL (Cochrane Controlled Trials Register) (04/2... (Complete abstract click electronic access below) / Resumo: Apesar de existirem controvérsias, alguns serviços utilizam a pesquisa de corpo inteiro (PCI) com 131I previamente a dose terapêutica com esse radionuclídeo no tratamento dos cânceres diferenciados da tiroide (CDT). Os defensores dessa conduta argumentam uma melhor otimização da dose ablativa, e os contrários afirmam que essa PCI poderia ocasionar o “efeito stunning”, caracterizado pela redução da captação tecidual do 131I no tratamento com a dose ablativa, comprometendo com isso o tratamento e o prognóstico desses indivíduos. Objetivo: avaliar se a PCI com 131I, pré-dose ablativa, interfere na eficácia da dose terapêutica de iodo quanto a remissão da doença após a tireoidectomia total ou quase total em indivíduos com CDT. Metodologia: foi realizada uma revisão sistemática da literatura na qual foram incluídos estudos controlados randomizados, não randomizados e observacionais, nos quais os pacientes estavam em pós-operatório de tireoidectomia total ou subtotal devido um dos CDT, e foram alocados a um dos dois grupos: PCI diagnóstica com 131I realizada antes da dose terapêutica com I131(intervenção), ou a PCI realizada com 123I antes da dose ablativa, ou não realização da PCI diagnóstica antes da dose terapêutica (ambos controle). O desfecho principal foi a remissão da doença avaliada pela taxa de sucesso ablativo em pelo menos seis meses de seguimento. Resultados: depois de realizadas as pesquisas nas bases eletrônicas Embase (1980–25/04/2017), Pubmed (1966–25/04/2017), CENT... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

The screening mammography programme has been running succesfully in the Czech republic for 13 years. Due to its ability to uncover earlystages of breast cancer, it helps to fight this serious disease. Although the positive outcome of this programme in the Czech republic has been already proved, there is only approximately 50% of women who have been regularly treated with it.One of the major reasons for this fact is a fear of cancer induction caused by the use of X-rays during the mammography. The main goal of this thesis is to calculate the risk of breast cancer induction caused by the mammography and to compare benefits of the screening programme for a woman who goes for regular checkups and a woman who does not. The measurement of concrete doses was made in one screening centre center located in western bohemia region. The group of observed patients at the age of 45-59 was divided into three categories. The object of measurement was an average dose received during the screening mammography, plus an average dose received during an additional mammography, which may sometimes occure during the examination. These data was studied through a statistic investigation to prove that the received dose is not dependent on the patient´s age. In the theoretical part of this work main principals of the screening mammography programme and mammography itself are repeated. The methods of statistic investigation and the methodology for estimating breast cancer risks based on recommendations of ICRP Publication 103. In the practical part was proved, that the average dose received during the classical mammography does not depend on the age of the patient. This could not be proved for an additional mammography dose, because of not sufficient group of statistic data. The main hypothesis, that regular checkups using the mammographical screening programme is benefical for women , was verified.

Os aminoglicosídeos permanecem sendo um dos principais antibióticos no tratamento de infecções causadas por bactérias gram-negativas, apesar do surgimento de novos antibióticos. Na Unidade de Endoscopia Digestiva do Hospital de Clínicas de Porto Alegre os aminoglicosídeos, combinados com antibióticos ß-lactâmicos, têm sido utilizados no tratamento de infecções das vias biliares e como antibiótico profilático em procedimento como a colangiopancreatografia endoscópica retrógrada. O objetivo do presente estudo foi comparar a eficácia terapêutica da dose única total diária com dose fracionada diária de gentamicina no tratamento da infecção das vias biliares, baseando-se na concentração biliar de gentamicina obtida nesses dois regimes terapêuticos e sua relação com a concentração inibitória mínima das principais bactérias isoladas na bile de pacientes com infecção do trato biliar. Os pacientes selecionados foram randomizados para tratamento com gentamicina na dose de 4mg/kg de peso por meio intravenoso sendo divididos em 2 grupos: grupo 1 recebeu dose única diária dividida em 3 horários (8 / 8 horas) e o grupo 2 recebeu o fármaco como dose única total diária. Os resultados do estudo evidenciaram que os níveis biliares de gentamicina nos pacientes tratados com dose única diária de gentamicina (grupo 2) ultrapassaram de 3 a 6 vezes as concentrações inibitórias mínimas das bactérias gram-negativas isoladas, enquanto que os níveis de gentamicina à nível biliar nos pacientes tratados com dose fracionada de gentamicina (grupo 1) conseguiram igualar ou ultrapassar no máximo e 3 vezes, dependendo da bactéria gram-negativa testada, as concentrações inibitórias. Além disto, os níveis biliares de gentamicina dos pacientes tratados com dose única diária permaneceram por intervalo superior a 14 horas acima das concentrações inibitórias mínimas destas bactérias, reforçando ainda mais o efeito pós-antibiótico obtido no intervalo de tempo onde não são detectados mais níveis de gentamicina na bile. Baseado nos efeitos bactericida dependente da concentração e efeito pós-antibiótico dos aminoglicosídeos,os resultados deste estudo sugerem que a dosagem única diária de gentamicina apresenta maior eficácia terapêutica que a dosagem fracionada diária no tratamento da infecção das vias biliares.

Le cadmium (Cd) est un élément toxique. Les activités humaines ont contaminé un large éventail de sols agricoles. L'exposition de l'homme au Cd se fait majoritairement par voie alimentaire, notamment à travers les aliments de base tels que les céréales. Le blé dur accumule naturellement plus de Cd dans ses grains que les autres céréales. Une fraction significative de la production française de blé dur dépasse la limite réglementaire européenne fixée pour le Cd. Il est donc nécessaire de réduire l'accumulation de Cd dans les grains de blé dur. Cette thèse portant sur l'écophysiologie de l'allocation du Cd aux grains chez le blé dur a pour ambition d'aider au développement de stratégies agronomiques visant à réduire le niveau de contamination en Cd du blé dur et de ses dérivés.Dans un premier temps, nous avons étudié la relation entre la structure de la biomasse aérienne et l'allocation de Cd aux grains. Nous avons fait l'hypothèse que la répartition de la biomasse aérienne entre pailles et grains était un facteur déterminant de l'allocation du Cd aux grains. Huit cultivars Français de blé dur - de hauteur de paille contrastée - ont été cultivés en présence de Cd. Comme prévu, le principal facteur expliquant la différence d'accumulation de Cd dans le grain était la structure de la biomasse aérienne. Les cultivars allouant une plus grande proportion de leur biomasse aérienne aux pailles - autrement dit les cultivars à longue tige - avaient tendance à accumuler moins de Cd dans leurs grains, car les tiges et les feuilles sont des puits de Cd en concurrence avec les grains lors de leur remplissage.Les minéraux importés dans les grains proviennent soit de leur absorption directe par la racine après l'anthèse, soit de leur remobilisation depuis des réserves constituées avant l'anthèse. La deuxième partie de ce travail a été consacrée à déterminer l'importance quantitative de ces deux « sources » pour le Cd chez le blé dur, et de préciser comment leur contribution relative varie entre cultivars et avec le niveau d'azote (N). Le traçage isotopique a été utilisé pour suivre le flux de Cd absorbé après l'anthèse. L'impact du niveau d'azote a été testé en privant la moitié des plantes de N après l'anthèse, sur deux cultivars montrant une capacité contrastée à accumuler le Cd dans leurs grains. La contribution de la remobilisation a été estimé à 50%, ce qui signifie que la moitié du Cd accumulé dans les grains provenait du Cd prélevé après l'anthèse. Le Cd a été remobilisé à partir des tiges, peut-être des racines, mais pas à partir des feuilles. La contribution de la remobilisation n'a pas varié entre les deux cultivars, de sorte qu'aucune relation entre la « source » de Cd et son niveau d'accumulation dans le grain n'a été mise en évidence. La privation d'azote en phase de remplissage a stimulé la remobilisation de N sans affecter celle de Cd, ce qui suggère que la remobilisation de Cd est un processus indépendant de la sénescence.En troisième lieu, nous avons examiné comment les caractéristiques d'allocation de Cd aux grains étaient modulées par le niveau d'exposition au Cd. [...]Enfin, nous nous sommes intéressés à la localisation de Cd dans le grain. [...] Ce travail a fourni la première carte de localisation de Cd dans un grain de blé dur. La distribution de Cd s'est caractérisée par une forte accumulation de Cd dans le sillon et par une dissémination dans l'endosperme amylacé plus prononcée que celle de Fe et Zn. / Cadmium (Cd) is a toxic element. Human activities have contaminated a wide range of agricultural soils. Most of Cd entering human bodies is through the dietary intake, and especially through staple food like cereals. Durum wheat naturally accumulates more Cd in its grains than other cereals. A significant fraction of the French durum wheat production has been found to exceed the European regulatory limit set for Cd. There is thus a need to reduce the accumulation of Cd in durum wheat grains. This thesis is dedicated to a better understanding of the ecophysiology of Cd allocation to the grains in durum wheat, with the ambition of helping to find agronomic strategies to reduce the Cd contamination level of durum wheat products.In first, we investigated the relationship between the aboveground partitioning of Cd and the shoot allometry. We hypothesized that the partitioning of shoot biomass between grains and straws is a driver of the allocation of Cd to the grains. Eight French durum wheat cultivars differing in their stem height were grown in presence of Cd. As expected, the main factor explaining the difference in their grain Cd was the shoot biomass partitioning. Cultivars allocating a higher proportion of their aerial biomass to the straws, i.e. long-stem cultivars, tended to accumulate less Cd in their grains because stems and leaves are sinks for Cd in competition with developing grains.Minerals imported into cereal grains originate from either direct post-anthesis root uptake or from the remobilization of pre-anthesis stores. The second part of this work was dedicated to determine the quantitative importance of these two pathways for Cd in durum wheat, and how their relative contribution vary between cultivars and with the level of nitrogen (N) supply. Stable isotopic labelling was used to trace the flux of Cd taken up post-anthesis. The impact of N supply was tested by depriving half of the plants of N after anthesis, in two cultivars showing a contrasted ability to accumulate Cd in their grains. The contribution of Cd remobilization was around 50%, which means that half of Cd in grains originated from Cd taken up pre-anthesis. Cd was remobilized from stems, possibly from roots, but not from leaves. The contribution of remobilization did not vary between the two cultivars so that no relationship between the pathway and the level of accumulation of Cd in grain was evidenced. Post-anthesis N deprivation triggered the remobilization of N without affecting that of Cd, which suggests that Cd remobilization is a senescent-independent process.In third, we investigated how the characteristics of Cd allocation to the grains was affected by the level of Cd exposure. [...]In last, we focused on how Cd was distributed within durum wheat grains. [...] This work provided the first map of Cd localization in durum wheat grains. Cd distribution was characterized by a strong accumulation of Cd in the crease and by a non-negligible dissemination in the starchy endosperm, as compared to Fe and Zn.

Made available in DSpace on 2016-04-04T12:26:00Z (GMT). No. of bitstreams: 2 2.pdf: 3729000 bytes, checksum: 78661b59dc7c742033ca6ce5a153cc47 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2013 / Fundação Oswaldo Cruz. Instituto de Tecnologia em Fármacos/Farmanguinhos. Rio de Janeiro, RJ, Brasil. / O crescimento do número de casos de tuberculose no Brasil fez com que o Governo Federal desenvolvesse uma política nacional de controle da tuberculose que possibilitasse melhorar e prolongar a qualidade de vida dos indivíduos infectados. Esta política inclui, entre várias outras iniciativas, o aumento na adesão de pacientes com um tratamento terapêutico adequado utilizando Formulações de Doses Fixas Combinadas (FDC), contendo os fármacos aos quais o bacilo de Koch é mais sensível. Um dos pontos críticos para o desenvolvimento de tuberculostáticos é o desenvolvimento de metodologias analíticas para seu controle que sejam viáveis, eficazes e robustas, uma vez que a rifampicina um dos insumos farmacêuticos ativos (IFAs) da associação apresenta características peculiares como a sua baixa estabilidade em solução, o que pode levar à formação de muitos produtos de degradação. O presente estudo tem por objetivo otimizar e validar uma metodologia analítica que seja adequada à rotina de um laboratório de controle de qualidade para a determinação dos fármacos isoniazida e rifampicina (ambos IFAs da formulação) e suas substâncias relacionadas, associados em comprimidos de dose fixa combinada para serem utilizados no tratamento dos casos da tuberculose e serem distribuídos pelo Sistema Único de Saúde. Para tanto, foi otimizada e validada uma metodologia analítica utilizando a técnica de cromatografia líquida de alta eficiência (CLAE) capaz de determinar não só o teor dos insumos farmacêuticos ativos (IFAs) presentes na formulação, mas também de quantificar as suas substâncias relacionadas. Um estudo de estabilidade de longa e acelerada durações também foi conduzido e a metodologia analítica otimizada e validada foi usada para avaliação dos comprimidos, mostrando sua capacidade de detectar o esperado decaimento do teor dos IFAs e o aumento no teor de suas substâncias relacionadas. Posteriormente, houve a transferência do método para a técnica de cromatografia líquida de ultraeficiência (CLUE), visando uma análise cromatográfica em tempo mais curto e uma maior sensibilidade do método. Essa metodologia utilizando a técnica de CLUE também foi validada. / As the number of tuberculosis (TB) cases in Brazil is rising, the brazilian Government implemented a national policy for TB control that would enable to improve and endure the quality of life in infected individuals. This policy includes, among many actions, the increase of the patient’s adhesion by a therapeutic treatment using suitable formulations of Fixed Dose Combination (FDC) including drugs to which M. tuberculosis is more sensitive. One critical point for FDC formulation development is the establishment of viable, effective and robust analytical methods for its quality control, since rifampicin – one of the formulation’s active pharmaceutical ingredient (API) – has particular characteristics such as its low stability in aqueous solution, which can lead to formation of many degradation products. This study aims to optimize and validate an analytical methodology for the determination of isoniazid and rifampicin (both APIs in the formulation) and their related substances en tablets with fixed dose. This medicines will be distributed by the national health system for the treatment of tuberculosis patients. Therefore, an analytical method was optimized and validated using the technique of high performance liquid chromatography (HPLC) that can evaluate not only the dosage of APIs in the formulation, but also to determine their related substances. A stability study of accelerated and long durations was also conducted and the optimized analytical method was used to evaluate the tablet, showing its ability to detect the expected reduction of API dosage and the increase in the amount of its related products. Later, an upgrade of the optimized and validated method to ultra-high performance liquid chromatography (UPLC) was succefully performed, with the reduced chromatographic analysis time and increased sensitivity. This UPLC methodology has also been validated.