Dissertations / Theses on the topic 'Individual toxicity'

The use of biomarkers is considered a promising alternative, or complement, to traditional ecotoxicological assays. Toxic effects are often initially manifested at the molecular or biochemical level, biomarkers are therefore used as sensitive indicators of toxic exposure. Ideally, biomarkers would also indicate reduced fitness and possible later effects at the individual or population levels. However, implementing biomarkers in ecotoxicology is challenging and few biomarkers have an established connection to reduced individual fitness. The aim of this thesis was to increase the value and improve the interpretation of biomarker responses in ecotoxicological studies by examining the impact of confounding factors and the relationship between oxidative biomarkers and reproductive effects in crustaceans. The sensitivity of biomarkers was confirmed in paper I as toxic effects of pharmaceuticals with conserved drug target orthologs were observed at the molecular and biochemical levels both earlier and at lower concentrations than effects on mortality and reproduction. No toxic effects were observed for the pharmaceutical without identified drug target orthologs, thus stressing the importance of considering toxic mechanisms and being aware of the most likely target when evaluating toxic effects also in non-target species. Many xenobiotics and environmental stressors interfere with oxidative processes, making oxidative biomarkers interesting to study in ecotoxicology and stress ecology. Still, feeding rate was identified as a confounding factor for antioxidant capacity (assayed as oxygen radical absorbance capacity, ORAC) and lipid peroxidation in ecotoxicological studies (paper II). However, ORAC normalized to protein was independent of altered feeding rates, hence it can be applied as a suitable exposure biomarker without considering alterations and effects of feeding rate. The connection between reproduction and oxidative stress is dual, as reproduction both can be inhibited by oxidative stress and induce pro-oxidative processes. Further, a positive association was found between ORAC and the occurrence of embryo aberrations in the benthic amphipod Monoporeia affinis (paper III). An association between antioxidant defense and reproduction was also observed for Daphnia magna (paper IV). Threshold values for identification of exposed individuals and prediction of possible later reproductive effects were established for ORAC. This thesis has contributed to diminishing some of the knowledge gaps limiting the use of oxidative biomarkers in ecotoxicology, by contributing to increased understanding of how oxidative biomarkers relate to important life-traits. Moreover, ORAC has been identified as a suitable biomarker of not only exposure, but also reproductive effects. Future research should continue to establish connections between biomarker responses and effects at higher levels, and focus on providing defined threshold values to enable predictions about later effects.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

Le déoxynivalénol (DON) est une mycotoxine de type trichothécène de type B, principalement produite par le genre Fusarium. C'est l'une des mycotoxines les plus répandues, elle est largement trouvée dans les céréales et les produits dérivés des céréales. Le cadmium est un composant de la croûte terrestre et un polluant environnemental courant. C'est un métal trace non essentiel et toxique pour la santé des humains et des animaux. Bien que la toxicité individuelle du DON et du Cd ait été bien étudiée, leur effet combiné est peu étudié. L'intestin étant le premier organe ciblé par les contaminants alimentaires, le but de cette étude est d'explorer l'effet combiné du DON et du Cd sur la fonction de barrière intestinale à l'aide de modèles in vitro, in vivo et ex vivo. In vitro, des cellules épithéliales intestinales humaines Caco-2 ont été traitées avec une série de concentrations de DON et de Cd (0-30 μM) seules ou en combinaison. La fonction de barrière des cellules Caco-2 a été évaluée par la mesure de la résistance électrique transépithéliale (TEER), de la perméabilité paracellulaire et des protéines jonctionnelles. Le mélange DON, Cd et DON+Cd a diminué le TEER et augmenté la perméabilité paracellulaire de manière dépendante de la concentration. L'abondance des protéines jonctionnelles E-cadhérine et occludine a été considérablement réduite dans les cellules exposées au DON, au Cd et au DON+Cd, tandis que l'expression de ZO-1 et de claudine-3 et -4 est restée inchangée. Le mélange DON Cd a eu des effets légèrement supérieurs ou similaires à ceux du contaminant le plus toxique. In vivo, les rats ont été exposés à des aliments contaminés par du DON (8,2 mg / kg), et à de l'eau de boisson contaminée par du Cd (5 mg / L) ou au mélange DON+Cd pendant 4 semaines. Les résultats n'ont montré aucun effet sur la prise de poids corporel au cours de l'expérience. Des dommages morphologiques légers caractérisés par un oedème au niveau de la lamina propria et un aplatissement et une fusion des villosités ont été découverts chez le rat exposé à chaque contaminant. Le score lésionnel du jéjunum était plus élevé chez tous les animaux traités que chez les animaux témoins. Une diminution significative de la profondeur de la crypte jéjunale a été observée chez les rats exposés au DON, au Cd et au DON+Cd, alors que la hauteur des villosités n'était pas affectée. Une immunomarquage plus faible de l'E-cadhérine dans le jéjunum de rats exposés à des contaminants seuls ou en association a également été observée, alors que l'occludine n'a diminué que chez les rats exposés au DON et au DON+Cd. Comme indiqué in vitro, l'exposition in vivo au DON et au Cd a induit des effets similaires à ceux du contaminant le plus toxique. Des explants jéjunaux de porcs ex vivo ont été exposés au DON (0-24 μM), au Cd (0-96 μM) et à la combinaison de DON+Cd. Le DON seul et le mélange DON Cd ont stimulé la réponse immunitaire chez le jéjunum en régulant positivement l'expression d'ARNm de IL-1, IL-1, IL-8 et TNF- de manière dose-dépendante, tandis que le Cd seul n'a pas affecté ces gènes. L'expression génique des métallothionéines (MT), y compris MT1A et MT2A, était régulée positivement de manière dose-dépendante par le Cd seul et le mélange, mais n'était pas affectée par le DON seul. La régulation à la hausse des gènes de cytokines et de MT induite par le DON+Cd était similaire à celle obtenue par le DON ou le Cd seul. En conclusion, le DON et le Cd modifient tous deux la fonction de barrière intestinale et l'effet combiné est similaire avec leur effet individuel. L'effet du mélange n'a démontré aucune synergie, ce qui suggère que la réglementation sur chaque contaminant protège suffisamment les consommateurs exposés aux mélanges de DON et de Cd
Deoxynivalenol (DON) is a type B trichothecene mycotoxin mainly produced by Fusarium genus. It is one of the most prevalent mycotoxins widely found in cereals and cereal-derived products. Cadmium is a component of earth’s crust and also a common environmental pollutant. It is a nonessential trace metal and toxic for humans and animals health. Although the individual toxicity of DON and Cd has been well investigated, their combined effect is poorly studied. As intestine is the first organ targeted by food contaminants, the aim of this study is to explore the combined effect of DON and Cd on the intestinal barrier function using in vitro, in vivo and ex vivo models. In vitro, the human intestinal epithelail cells Caco-2 were treated with a series of concentrations of DON and Cd (0-30 μM) alone or in combination. The barrier function of Caco-2 cells was assessed through the measurement of transepithelial electrical resistance (TEER), paracellular permeability and junctional proteins. DON, Cd and DON+Cd mixture decreased the TEER and increased the paracellular permeability in a concentration-dependent manner. The abundance of junctional proteins E-cadherin and occludin was considerably reduced in cells exposed to DON, Cd and DON+Cd, while the expression of ZO-1, and claudin-3 and -4 remained unchanged. The mixture DON+Cd induced slightly higher or similar effects than the most toxic contaminant. In vivo, rats were exposed to DON-contaminated feed (8.2 mg/kg feed), and Cd-contaminated drinking water (5 mg/L) or to the mixture DON+Cd for 4 weeks. The results showed no effect on body weight gain during the experiment. Mild morphological damage characterized by edema in lamina propria and villi flattening and fusion was found in rat exposed to each contaminant. The lesional score of jejunum was higher in all the treated animals than that in control animals. A significant decrease of jejunal crypt depth was observed in rats exposed to DON, Cd and DON+Cd, whereas villi height remained unaffected. A lower immunostaining of E-cadherin in the jejunum of rats exposed to contaminants alone or in combination was also observed, whereas occludin was only decreased in rats exposed to DON and DON+Cd. As shown in vitro, in vivo exposure to both DON and Cd induced similar effects than the most toxic contaminant. Ex vivo, jejunal explants of pigs were exposed to DON (0-24 μM), Cd (0-96 μM) and in combination DON+Cd. DON alone and mixture DON+Cd stimulated immune response in jejunum by upregulating mRNA expression of IL-1, IL-1, IL- 8 and TNF- in a dose-dependent manner, while Cd alone did not affect these genes. Gene expression of metallothioneins (MTs) including MT1A and MT2A was dose-dependently upregulated by Cd alone and mixture, but not affected by DON alone. The upregulation of cytokine and MTs genes induced by DON+Cd was similar than by DON or Cd alone. In conclusion, both DON and Cd alter intestinal barrier function and the combined effect is similar with their individual effect. The effect of the mixture did not demonstrate any synergy, suggesting that regulation on individual contaminant is protective enough for consumers exposed to DON and Cd mixtures

5 à 15% des 175 000 patients traités par radiothérapie (RT) chaque année sont exposés à une toxicité considérée comme « inhabituelle » pouvant entraîner des séquelles parfois graves. Les techniques innovantes de photonthérapie apportent une solution balistique pertinente mais inappropriée pour certaines tumeurs ou certains patients. Deux approches permettent d'entrevoir des solutions à ces situations. 1- Contribution au développement de l'hadronthérapie par ions carbone : Ces particules possèdent une masse et une charge qui leur confèrent un avantage balistique et biologique particulièrement intéressant. Le caractère rare des tumeurs éligibles et le très faible nombre de centres n'ont pas permis, ou justifié, à ce jour la réalisation d'études comparatives randomisées afin d'en évaluer le service rendu. Via le projet FP7 ULICE, nous avons intégré et animé plusieurs groupes à l'échelle nationale et internationale. Nous avons directement produit des procédures unifiées en terme d'immobilisation, de recueil des données élémentaires, de structuration protocolaire et de transformation des données en métadonnées échangeables. Nous avons proposé des concepts originaux permettant de décrire la dose prescrite et les volumes d'intérêt, au-delà du concept réducteur d'EBR. 2- Un nouveau biomarqueur de radiosensibilité individuelle (RSI). L'identification des patients les plus à risque de développer les réactions les plus sévères reste un enjeu majeur. Aucun test de RSI ne s'impose comme gold standard. A partir de primocultures fibroblastiques issues de patients ayant présenté un profil de toxicité inhabituel à la RT, le taux de cassures double brins résiduelles à 24h estimé par immunofluorescence indirecte (marqueur γH2AX) a permis de définir 3 groupes de RSI. Toutefois ce seul marqueur n'est pas assez robuste. Le délai de transit cyto-nucléaire de la protéine ATM semble affiner notre classification. Un nouveau modèle mécanistique a ainsi pu être développé
5 to 15% of the 175,000 patients treated with radiation therapy (RT) annually are exposed to toxicity considered "unusual" that can lead to serious sequelae. Innovative photon RT techniques provide relevant but inappropriate ballistic solution for certain tumors or certain patients. Two approaches guide solutions to these situations.1- Contribution to the development of carbon ion RT. These particles possess a mass and a charge that give them particularly interesting ballistics and biological properties. The rarity of eligible tumors and the low care offer have failed conducting randomized controlled trials to evaluate its cost-effectiveness. Throughout the FP7-ULICE project, we directly produced standard operating procedures in terms of basic data collection, protocol structuring and processing of metadata. We proposed original concepts to describe and report the dose and volume of interest, beyond the restricted concept of RBE. 2- A novel biomarker of individual radiosensitivity (IRS). The identification of the patients the most at risk of developing the most severe reactions remains a major challenge. There is no gold standard in the field of IRS assays.From fibroblasts primocultures sampled from patients with an unusual toxicity, the number of residual DNA double-stand breaks 24h after radiation and estimated by indirect immunofluorescence (marker γH2AX) allows to identify three groups of IRS. However this single marker is not robust enough. The delay of ATM nucleoshuttling appears to refine our classification. A new mechanistic model has been developed

To protect the environment from contaminants, environmental risk assessment (ERA) evaluates the risk of adverse effects to populations, communities and ecosystems. Environmental management decisions rely on ERAs, which commonly are based on a few endpoints at the individual organism level. To bridge the gap between what is measured and what is intended for protection, individual-level effects can be integrated in population models, and translated to the population level. The general aim of this doctoral thesis was to extrapolate individual-level effects of harpacticoid copepods to the population level by developing and using population models. Matrix models and individual based models were developed and applied to life-history data of Nitocra spinipes and Amphiascus tenuiremis, and demographic equations were used to calculate population-level effects in low- and high-density populations. As a basis for the population models, individual-level processes were studied. Development was found to be more sensitive compared to reproduction in standard ecotoxicity tests measuring life-history data. Additional experimental animals would improve statistical power for reproductive endpoints, but at high labor and cost. Therefore, a new test-design was developed in this thesis. Exposing animals in groups included a higher number of animals without increased workload. The number of reproducing females was increased, and the statistical power of reproduction was improved. Individual-level effects were more or equally sensitive compared to population-level effects, and individual-level effects were translated to the population level to various degrees by population models of different complexities. More complex models showed stronger effects at the population level compared to the simpler models. Density dependence affected N. spinipes populations negatively so that toxicant effects were stronger at higher population densities. The tools presented here can be used to assess the toxicity of environmental contaminants at the individual and population level, improve ERA, and thereby the basis for environmental management.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Manuscript.

Se evaluó la toxicidad individual y binaria de los plaguicidas metomilo y rotenona en la macrofita Lemna minor (Linnaeus, 1753) para determinar la acción sinérgica o antagónica de una mezcla equitóxica. Los ensayos se realizaron bajo condiciones de laboratorio (T 29 ± 2°C; H 48,6 ± 9,4 %) y los resultados fueron analizados con los programas estadísticos BMDS® y Probit para calcular la concentración efectiva media (CE50) a través de los parámetros Área de la Fronda (AF) y Nuevas Frondas (NF). Los resultados sugieren una mayor precisión al utilizar el Método del Punto de Referencia del programa BMDS® para el cálculo de la concentración efectiva. Adicionalmente, se calculó la concentración total de clorofila (CTC) y peso húmedo (PH) para determinar la inhibición del crecimiento (Ir). Del mismo modo, se realizó una comparación entre los valores NOAEL (nivel de efecto no observado) y LOAEL (nivel bajo de efecto observado) versus los valores de BMDL (límite inferior del punto de referencia) y BMD (nivel de variación en el punto de referencia), respectivamente. El análisis muestra que existe una mayor precisión al emplear los valores BMD y BMDL. La acción fitotóxica varió según el parámetro analizado. La CE50 mostró mayores valores en el parámetro NF (1079,22 mg·L-1 para rotenona; 7147,42 mg·L-1 para metomilo; 597,904 mg·L-1 mezcla binaria: metomilo y 298,93 mg·L-1 mezcla binaria: rotenona) que en el parámetro AF (782,173 mg·L-1 para rotenona; 6919,79 mg·L-1 para metomilo; 629,513 mg·L-1 mezcla binaria: metomilo y 314,754 mg·L-1 mezcla binaria: rotenona). Finalmente, el modelo de concentración-adición mostró que la acción fitotóxica de la mezcla de ambos plaguicidas en Lemna minor tiene un efecto sinérgico. Macrophyte Lemna minor (Linnaeus, 1753) was used to evaluate the phytotoxicity of the individual and mix action of methomyl and rotenone pesticides under laboratory conditions (Temperature 29 ± 2°C; Humidity 48,6 9,4 %). The taken measures to establish half effective concentration (EC50) were the frond area (AF) and production of new fronds (NF). In this study, BMDS® and Probit stadistical data analyses were used to compare the results about effective concentration. Results suggest Benchmark dose method of BMDS® program was more effective than Probit program when EC50 were determined. Additionally, total chlorophyll concentration (CTC) and humidity weight (PH) parameters were calculated to determinate the growth inhibition (Ir). Likewise, NOAEL (no observed adverse effect level) and LOAEL (low observer adverse effect level) were compared with BMDL (lower bench mark dose) and BMD (Bench mark dose), respectively. BMD and BMDL values were more accurate than NOAEL and LOAEL values. Phytotoxic action varied according the parameter. EC50 values of Lemna minor showed poor sensibility to methomyl pesticide with an elevated concentration in both parameters (6919,79 mg•L-1 and 7147,42 mg•L-1 for AF and NF, respectively). Results of rotenone pesticide were lower than methomyl, with 1079,22 mg•L-1 (NF) and 782,173 mg•L-1 (AF). Finally, the mix toxicity was 597,904 mg•L-1 (methomyl: NF), 298,93 mg•L-1 (rotenone: NF), 629,513 mg•L-1 (methomyl: AF) and 314,754 mg•L-1 (rotenone: AF). For synergy calculation, Concentration-Adition value was used, concluding a higher synergism.

The primary objectives of this thesis are to develop a systematic method for patients to self-report pelvic radiotherapy adverse events (AE) using electronically collected patient reported outcomes (PROs) in clinical practice and to evaluate patient-reported toxicity in association with radiotherapy dosimetric data and clinical factors. Before testing the research objectives in two observational studies, important practical and methodological issues were addressed. Analysis from systematic and literature reviews, content analysis of three validated PRO systems and interviews with health professionals found the European-Organisation-for-Research-and-Treatment-of-Cancer-Quality-of-Life-Questionnaires (EORTC-QLQ) C30 and cancer-specific modules to have the most effective coverage of acute and late AE for patient treated with radiotherapy for anal, rectal, endometrial and cervical cancer. Qualitative analysis of patient cognitive interviews found the EORTC-QLQ system was acceptable to patients and revealed discrepancies in toxicity grading between patient and clinician (using the Common-Terminology-Criteria-of-Adverse-Events (CTCAE)) might be due to inherent differences in the grading descriptions between the scoring systems. Electronic methods for collection and presentation of PRO data were developed alongside technology to improve clinical data capture from electronic health records (EHR). A pilot study of 31 patients proved it was feasible to collect electronic and paper PRO data and integrate results into individual EHRs. A protocol for organ at risk (OAR) contouring and methods used for dose-volume-histogram (DVH) export were developed. The cross sectional (n=315) and prospective studies (n=129) found bowel urgency and sexual dysfunction to be the late AE most commonly reported by patients. The cross sectional study piloted the application of principal component analysis to describe DVH data from patients treated with multiple radiation techniques and demonstrated associations between PRO late toxicity and dosimetric and clinical data. The prospective study interim analysis found resolution of many treatment-related symptoms by six-months and provided encouraging findings for the use of longitudinal PRO collection in routine practice.

Ces travaux de thèse s’inscrivent dans le contexte de la prédiction de la toxicité en radiothérapie du cancer de la prostate. Dans l'objectif d'analyser les corrélations spatiales entre la dose et les effets secondaires cette problématique est abordée dans un cadre d'analyse de population. La mise en correspondance inter-individus de l'anatomie et de la distribution de dose planifiée soulève des difficultés liées aux fortes variabilités anatomiques et au faible contraste des images CT considérées. Nous avons envisagé différentes stratégies de recalage non-rigide exploitant les informations relatives aux structures anatomiques, aux combinaisons intensité-structure, ou aux relations inter-structures. Les méthodes proposées s'appuient notamment sur l’utilisation de descripteurs structurels des organes tels que les cartes de distances euclidiennes ou du champ scalaire solution de l’équation de Laplace. Ces méthodes ont permis d'améliorer significativement la précision de la mise en correspondance, tant au niveau anatomique que dosimétrique. Les plus performantes ont été utilisées pour analyser une population de 118 individus. Les comparaisons statistiques des distributions de dose entre les patients souffrant ou non de saignements rectaux ont permis d’identifier une sous-région du rectum où la dose semble corrélée à la toxicité. La sous-région rectale identifiée apparaît potentiellement impliquée et hautement prédictive du risque de saignement. L'approche proposée permet d’améliorer les performances des modèles mathématiques de prédiction de la toxicité
This thesis deals with the issue of predicting the toxicity within the context of prostate cancer radiotherapy. With the aim of analyzing the spatial correlations between dose and side effects, this problem is addressed in a population analysis framework. Inter-individual matching of both the anatomy and planned dose distribution raises difficulties related to high anatomical variability and low contrast in the CT images. We considered different strategies for non-rigid registration involving the use of information on anatomical structures, intensity-structure combinations, or inter-structures relations. The proposed methods are primarily based on the use of structural descriptors of organs such as Euclidean distance maps or scalar field solution of the Laplace equation. These methods allowed us to significantly improve the accuracy of the matching, at both the dosimetric and the anatomical level. The most accurate matching strategy has been used for analyzing a population of. Statistical comparisons of dose distributions between patients with or without rectal bleeding have been used to identify a rectal sub-region likely correlated with toxicity. The identified rectal sub-region appears potentially involved in side effects and highly predictive of the risk of bleeding. The proposed approach makes it possible to improve the performance of mathematical models for predicting the toxicity

La radiothérapie et la chimiothérapie sont deux des traitements recommandés pour traiter les cancers ORL localement avancés. La radiothérapie conventionnelle consiste en l’administration de 70 Grays en 35 fractions sur 7 semaines (fractionnement dit « conventionnel »). La chimiothérapie peut être administrée avant (induction), en même temps (concomitant) ou après (adjuvant) le traitement locorégional (chirurgie et/ou radiothérapie). Des essais randomisés ont étudié l’efficacité d’une modification du fractionnement et d’autres l’ajout d’une chimiothérapie à un traitement locorégional. Les méta-analyses sur données individuelles consistent à recueillir les bases de données de ces essais, les vérifier et ensuite les analyser ensemble, permettant ainsi des analyses plus poussées comme la variation de l’effet selon des caractéristiques des essais ou des patients. Cette thèse avait pour objectifs :1/ La première actualisation de la méta-analyse MARCH qui a inclus 34 essais et 11 969 patients afin de déterminer si la radiothérapie à fractionnement modifié était plus efficace que le fractionnement conventionnel sur la survie. Une analyse de la toxicité a également été réalisée. La question secondaire était de savoir si le fractionnement modifié seul était plus efficace que le fractionnement conventionnel associé à une chimiothérapie concomitante.2/ La seconde actualisation de la méta-analyse MACH-NC qui a inclus 105 essais et 19 511 patients afin d’estimer l’efficacité de l’ajout d’une chimiothérapie à un traitement locorégional. La question secondaire concernait la comparaison de l’efficacité de l’ajout d’une chimiothérapie concomitante à celui d’une chimiothérapie d’induction
Radiotherapy and chemotherapy are both recommended treatments for locally advanced head and neck cancers. During conventional radiotherapy, 70 Grays are given in 35 fractions over 7 weeks (called « conventional fractionation »). Chemotherapy may be given before (induction), at the same time (concomitant) or after (adjuvant) locoregional treatment (surgery and/or radiotherapy). Many randomized clinical trials studied the efficacy of altered fractionated radiotherapy and others studied the addition of chemotherapy to locoregional treatment. Individual patient data meta-analysis consists in the collection of the databases of the trials, the check and the analysis, together. It allows to perform advanced analyses like variation of the treatment effect over trials’ or patient’s characteristics. The objectives of the present work were:1/ The first update of the MARCH meta-analysis, which included 34 trials (from 1979 to 2010) and 11,969 patients in order to study the efficacy of altered fractionated radiotherapy compared to conventional fractionation. A toxicity analysis has also been performed. A secondary question was the efficacy of altered fractionation alone compared to conventional fractionation plus concomitant chemotherapy.2/ The second update of the MACH-NC meta-analysis, which included 105 trials (1965-2010) and 19,511 patients in order to study the efficacy of the addition of chemotherapy compared to locoregional treatment. A secondary question was the efficacy of the addition of concomitant chemotherapy compared to the addition of induction chemotherapy

Ce travail de thèse est une contribution à l'évaluation de l'impact des insecticides sur les entomophages parasitoi͏̈des de pucerons. Nous avons principalement étudié les effets sublétaux et populationnels des insecticides sur les parasitoi͏̈des de pucerons sur colza. Dans une première partie, nous avons tout d'abord déterminé grâce à un inventaire faunistique, que les parasitoi͏̈des de pucerons, Aphidius matricariae, Diaeretiella rapae et Aphidius ervi, étaient majoritaires sur les pucerons du colza en France. Dans une deuxième partie, nous avons mis en évidence au laboratoire que les insecticides sont hautement toxiques pour les parasitoi͏̈des et présentent un risque important pour ces insectes auxiliaires. Les effets sublétaux de différents insecticides ont été recherchés sur le comportement d'orientation olfactive et le comportement de ponte. Nous avons observé deux types d'effets sur le comportement d'orientation olfactive. Dans le cas de la lambda-cyhalothrine, une relation dose-réponse inverse (hormesis) est apparu, une DL0. 1 provoquant un effet négatif sur ce comportement alors que la dose DL20 n'en a pas eu. Dans le cas du triazamate, nous avons constaté une relation-dose réponse croissante. Les autres insecticides (pyrimicarbe, chlorpyriphos-éthyl et deltaméthrine) n'ont pas eu d'effet sur l'orientation olfactive. Nous avons aussi mesuré l'impact de deux pyréthrinoi͏̈des (lambda-cyhalothrine et deltaméthrine) sur le comportement de ponte des parasitoi͏̈des de pucerons. Nous avons mis en évidence un effet de la lambda- cyhalothrine sur ce comportement mais pas de la deltaméthrine. Dans une troisième partie, en conditions semi-naturelles sur colza en automne, nous avons montré l'absence d'effets de résidus de la deltaméthrine utilisée à une dose contre les altises, sur l'action des parasitoi͏̈des sur les populations du puceron Myzus persicae (dans le cas de parasitoi͏̈des introduits après traitement). Les effets de la deltaméthrine et des parasitoi͏̈des sur les populations de pucerons se sont avérés additifs
This work is a contribution to the evaluation of the impact of insecticides on aphid parasitoids. In particular, we have studied the sublethal effects on behaviour and effect on population dynamic of insecticides on the aphid parasitoids on oilseed rape. In a first part, we carried out a survey of the aphid parasitoids species present on oilseed rape in France. Our results highlighted two major species, Aphidius matricariae and Diaeretiella rapae on Myzus persicae and D. Rapae on Brevicoryne brassicae. Aphidius ervi was also found but in a lesser extent. In a second part, acute toxicity tests showed that insecticides used in oilseed rape induced a high toxicity. We found a high risk of mortality for aphid parasitoids at the field application rate. The sublethal effects of various insecticides on the orientation and oviposition behaviour were investigated. We found two types of effects on the orientation behaviour. In the case of the lambda-cyhalothrine, an inverted dose-response relationship (hormesis) were found. The response of females decreased after an exposure to LD0. 1 but not to LD20. In the case of the triazamate, we found a perturbation of orientation behaviour proportional to the dose of insecticide received. Other insecticides (pirimicarb, chlopyrifos-ethyl and deltamethrin) did not perturb orientation behaviour. We also evaluated the impact of two pyrethroids (lambda-cyhalothrin and deltamethrin) on the oviposition behaviour of aphid parasitoids. We showed an effect of the lambda-cyhalothrin on this behaviour but not for deltamethrin. In a third part, in semi-field conditions, we showed that aphid parasitoids could limit populations of M. Persicae in Fall even after a pyrethroid treatment against Coleoptera because the presence of deltamethrin residues has little impact on the parasitoid. We observed that both pesticide and parasitoid reduced the aphid population growth and that their effect added up

The application of pesticides in agricultural fields leads to inevitable contamination of adjacent freshwater systems, representing a serious threat to non-target aquatic invertebrate communities. The study of the impact of these stressors on ecologically relevant species is crucial for risk assessment. Traditionally, toxicity testing focuses on organism and population-level responses (e.g. mortality, growth, behavior, and reproduction). However, these responses are often preceded by changes at lower levels of biological organization. In this sense, there is a need to develop sensitive tools that can be used to predict ecological adverse effects of sub-lethal concentrations of pesticides. Assessing sub-organismal endpoints may therefore provide early indicators of pesticide exposure and their possible impacts on natural populations. In this thesis, larvae of Chironomus riparius (Meigen) were exposed to four insecticides with distinct modes of action: amitraz, spinosad, indoxacarb, and fipronil, and their effects evaluated in terms of life-history responses using standard laboratory ecotoxicological tests, and at biochemical level by monitoring specific oxidative stress, neuronal, and energy metabolism biomarkers. Moreover, the effects of spinosad, indoxacarb, and fipronil were assessed at the molecular level using proteomic tools, to determine if proteomics and biochemical biomarkers can be used as reliable and sensitive tools in ecological risk assessment. The results presented here indicate that environmentally relevant concentrations of the insecticides tested can significantly affect several C. riparius life-history traits, with reductions in the larval growth and impairment of emergence endpoints observed for all compounds tested, which ought to compromise the ecological integrity of freshwater ecosystems. At the biochemical level, very distinct responses were observed for each pesticide, probably due to their distinct modes of action. Nonetheless, evidences of high metabolic costs (as indicated by the increase of electron transport system (ETS) and/or lactate dehydrogenase (LDH) activities) were observed for all insecticides, which are probably associated with the activation of antioxidant defenses and detoxification processes. Additionally, evidences of oxidative damage were found in C. riparius larvae under exposure to amitraz and spinosad, as indicated by the increase in lipid peroxidation (LPO) levels. At the proteome level, no significant changes were found in C. riparius proteome between exposed and non-exposed larvae for the concentrations of indoxacarb tested. Fipronil exposure induced alterations in the expression of globins, cytoskeleton and motor proteins, as well as in proteins involved in protein synthesis. Exposure to spinosad resulted in alterations in globins, actin, and cuticle proteins’ expression. These changes observed at the proteome level revealed potential mechanisms of action that lead to the effects observed at the individual level. The potential of C. riparius globins expression in environmental monitoring studies has been previously stated and are here sustained. The generalized downregulation of these proteins observed under exposure to spinosad and fipronil may be related to the toxic effects of these insecticides. This study highlights the importance of complementing standard ecotoxicological approaches with biochemical and molecular tools in an integrative manner. The analyses of biochemical biomarkers and of the proteome can be useful in risk assessment, contributing to the knowledge of the sub-lethal effects of pesticides, thus aiding the comprehensive and mechanistically understanding of the mechanisms that lead to higher level responses. It is also demonstrated that the pesticides tested here pose a potential risk to non-target aquatic invertebrates, and therefore their application near freshwater systems should be reviewed. Chironomus riparius, a model organism in aquatic toxicology, is also presented as a promising model organism for environmental proteomics.
O uso de pesticidas em campos agrícolas resulta na inevitável contaminação dos sistemas de água doce adjacentes, representando uma séria ameaça para as comunidades de invertebrados aquáticos não alvo. O estudo do impacto destes compostos em espécies ecologicamente relevantes é crucial para a avaliação de risco. Tradicionalmente, os testes ecotoxicológicos baseiam-se em respostas ao nível do organismo e da população (ex. mortalidade, crescimento, comportamento e reprodução). No entanto, estas respostas observadas ao nível do organismo e população são usualmente precedidas por alterações nos níveis mais baixos de organização biológica. Nesse sentido, existe a necessidade de desenvolver ferramentas sensíveis que possam ser usadas para prever potenciais efeitos adversos ecológicos de concentrações sub-letais de inseticidas. A avaliação de efeitos ao nível subindividual pode assim fornecer informação prévia da exposição a pesticidas e os seus possíveis impactos em populações naturais. Nesta tese, larvas da espécie modelo em ecotoxicologia Chironomus riparius (Meigen) foram expostas a quatro inseticidas com diferentes modos de ação: amitraz, spinosad, indoxacarb e fipronil, e os seus efeitos avaliados em termos de respostas do ciclo de vida utilizando testes ecotoxicológicos padronizados, e ao nível bioquímico monitorizando biomarcadores específicos de stress oxidativo, neurotoxicidade e metabolismo energético. Além disso, os efeitos do spinosad, indoxacarb e fipronil ao nível molecular foram avaliados usando ferramentas de proteómica, com o objetivo de determinar se a proteómica e os marcadores bioquímicos podem ser ferramentas sensíveis na avaliação de risco ecológico. Os resultados aqui apresentados indicam que concentrações ambientalmente relevantes dos pesticidas testados, podem comprometer significativamente vários indicadores do ciclo de vida de C. riparius. Foram observadas reduções no crescimento larval e alterações nos parâmetros relacionados com a emergência dos insectos em resposta à exposição a todos os inseticidas testados, o que pode comprometer a integridade ecológica dos ecossistemas de água doce. Ao nível bioquímico, foram observadas respostas muito distintas para cada pesticida, provavelmente devido aos seus diferentes modos de ação. No entanto, foram observados indícios de elevados custos metabólicos (indicados pelo aumento das atividades da cadeia transportadora de eletrões (ETS) e/ou da enzima lactato desidrogenase (LDH) para todos os inseticidas. Estes aumentos estão provavelmente relacionados com a ativação de mecanismos de defesa antioxidantes e de processos de destoxificação. Além disso, foram observados indícios de dano oxidativo em larvas expostas a amitraz e spinosad, indicado pelo aumento nos níveis de peroxidação lipídica (LPO). Ao nível do proteoma, não foram observadas alterações significativas nas larvas expostas a indoxacarb em comparação com larvas não expostas. A exposição ao fipronil causou alterações na expressão de globinas, de proteínas motoras e do citoesqueleto, bem como em proteínas envolvidas na síntese proteica. A exposição ao spinosad resultou em alterações na expressão de globinas, actinas e de proteínas da cutícula. Estas alterações observadas ao nível do proteoma revelaram potenciais mecanismos de ação que levam aos efeitos observados ao nível do organismo. O potencial da expressão das globinas de C. riparius em estudos de monitorização ambiental foi previamente afirmado e é aqui sustentado. O decréscimo generalizado observado na expressão destas proteínas sob exposição ao spinosad e ao fipronil pode estar relacionado com os efeitos tóxicos destes inseticidas. Esta tese destaca a importância de complementar de uma forma integrada os ensaios ecotoxicológicos padronizados com ferramentas bioquímicas e moleculares. A análise de marcadores bioquímicos e do proteoma pode ser útil na avaliação de risco, contribuindo para o conhecimento dos efeitos sub-letais dos pesticidas, auxiliando na compreensão dos mecanismos que conduzem às respostas observadas nos níveis mais elevados de organização biológica. Este estudo revela também que os pesticidas testados representam um risco para os invertebrados aquáticos não alvo, e, portanto, a sua aplicação próxima de sistemas de água doce deve ser revista. Chironomus riparius, um organismo modelo em toxicologia aquática, é também aqui apresentando como um modelo promissor em estudos de proteómica ambiental.
Programa Doutoral em Biologia

The Canada-wide Standards for Petroleum Hydrocarbons (PHC CWS) in soils are remedial standards based on four petroleum distillates (Fraction 1 [F1; ECN C6-C10], Fraction 2 [F2; ECN >C10-C16], Fraction 3 [F3; ECN >C16-C34], and Fraction 4 [F4; ECN >C34-C50]). Knowledge gaps regarding petroleum toxicity to soil organisms were identified including concerns that the ecological values for F3 were overly conservative, possibly due to differences in toxicity between the low and high boiling point constituents of this distillate, and unexpected less-than-concentration-additive toxicity of binary mixtures of distillates to earthworms. An understanding of petroleum toxicokinetics with soil organisms was also needed to interpret toxicity results. Toxicity studies with one plant and two invertebrate (earthworm and collembolan) species were conducted with F3 and two subfractions of F3, F3a (ECN >C16-C22) and F3b (ECN >C22-C34), to determine if the toxicities of F3a and F3b were sufficiently different to recommend regulating the two separately. The difference in toxicities between the two was generally within the range of variability noted for the toxicity tests and thus it was not recommended to regulate the two separately. The toxicity data indicated that the exposure duration of standard test methods may be insufficient for determining the toxicity of higher distillate ranges. Toxicokinetic studies conducted with earthworms and F2, F3a, and F3b confirmed that standard test durations generally were not of sufficient duration to attain maximum body residues with F3b and sometimes F3a. Internal exposure scenarios also differed among distillates, with various accumulation curves noted and attributed to differences in loss of distillate from the soil and changes in bioavailability. Aromatics were disproportionally accumulated by earthworms relative to the ratio of aromatics to aliphatics in soil, suggesting that aromatics were the main contributors to earthworm toxicity. Toxicity and toxicokinetic studies with binary combinations of F2, F3a, and/or F3b and earthworms demonstrated that, on a soil concentration basis, toxicity was less-than-additive. Toxicokinetics indicated that this was due to a decrease in the bioavailability of distillates when a second distillate was present presumably as a non-aqueous phase liquid. However, on an internal tissue concentration basis, results were closer in agreement with concentration-addition.

Yes
Electron‐deficient half‐sandwich complexes are a class of under‐studied organometallics with demonstrated potential as metallodrug candidates. The present study investigates the effect of two 16‐electron organoruthenium complexes ([( p‐ cym)Ru(benzene‐1,2‐dithiolato)] ( 1 ) and [( p ‐cym)Ru(maleonitriledithiolate)] ( 2 )) on the cell viability of non‐immortalised human lymphocytes from healthy individuals. The genotoxic effects of 1 and 2 in lymphocytes using the Comet and cytokinesis‐block micronucleus assays is also investigated. Gene expression studies were carried out on a panel of genes involved in apoptosis and DNA damage repair response. Results show that the two 16‐electron complexes do not have significant effect on the cell viability of human lymphocytes from healthy individuals. However, an increase in DNA damage is induced by both compounds, presumably through oxidative stress production.
This project was supported by the Royal Society (University Research Fellowship No. UF150295 to NPEB), the University of Bradford (RDF Award), and by the Academy of Medical Sciences/the Wellcome Trust/ the Government Department of Business, Energy and Industrial Strategy/ the British Heart Foundation Springboard Award [SBF003\1170 to NPEB].
The full-text of this article will be released for public view at the end of the publisher embargo on 30 Oct 2021.

碩士
國立臺灣大學
獸醫學研究所
97
The fish aquaculture was rapid development in Taiwan and the high density caused the highly risks for suffering several diseases. In order to treatment the diseases of fish, not only improving the cultivating environments and techniques, but also tried various chemical therapy drugs widely. Danofloxacin is an antibacterial drug of the fluoroquinolone group developed for use in veterinary medicine. Copper sulfate and potassium permanganate were enabled to use for keeping away the harmful organism as surface parasite, bacteria, alga and other harmful living organisms in water. The danofloxacin, copper sulfate and potassium permanganate were non- legal aquaculture drugs for fishery at present in Taiwan, but in fact the drugs were used commonly in aqua-cultured field and they used them mostly consult the foreign literature report. The purpose of this research provided the residues and acute toxicity of danofloxacin, copper sulfate and potassium permanganate individually to tilapia and grouper for fishery references. After single oral administration (10 mg/kg b.w.), the plasma, kidney, liver and muscle were collected, then the danofloxacin concentration of samples was determined by using high performance liquid chromatography. In tilapia, the result indicated that the maximal plasma, kidney and liver concentration were 1.438 μg/mL, 13.178 μg/g and 12.477 μg/g, respectively, at 6 h after administration. The maximal muscle concentration was 2.153 μg/g at 12 h after administration. The elimination half-time of plasma, muscle, kidney and liver were 28.76 h, 33.48 h, 43.58 h and 48.46 h, respectively. In grouper, the result indicated that the maximal plasma, kidney and liver concentration were 2.781 μg/mL, 5.020 μg/g and 0.753 μg/g, respectively, at 1 h after administration. The maximal muscle concentration was 0.450 μg/g at 4 h after administration. The elimination half-time of plasma, muscle, kidney and liver were 47.14 h, 28.06 h, 32.08 h and 41.50 h, respectively. The ED50 of danofloxacin in tilapia and grouper were respectively determined after examined by histopathological section. The ED50 of danofloxacin in tilapia were 37.5 ppm and 81.67 ppm, after administration for 3 days and 7days, respectively. The ED50 of danofloxacin in grouper were 173.33 ppm and 94.33 ppm, after administration for 3 days and 7days, respectively. By utilizing the atomic absorption spectrophotometer to determine the fish''s body residues of amount of copper and manganese. After 24h drug bath of copper sulfate and then transferred to clean water for 10 days, the residues of copper in muscle and liver of tilapia were 0.2087 ppm and 2.5373 ppm, respectively. On the other hand, the residues of copper in muscle and liver of grouper were 0.1769 ppm and 2.4583 ppm, respectively. After 4h drug bath of potassium permanganate and then transferred to clean water for 10 days, the residues of manganese in muscle and liver of tilapia were 0.2836 ppm and 1.9741 ppm, respectively. On the contrary, the residues of manganese in muscle and liver of grouper were 0.2024 ppm and 1.7524 ppm, respectively. The 96h LC50 of copper sulfate in tilapia and grouper were 30.5 ppm and 1.36 ppm, respectively. The 96h LC50 of potassium permanganate in tilapia and grouper were 3.60 ppm and 1.42 ppm, respectively.