Mammalian estrogens and estrogen-like compounds known as xeno-estrogens are being found in and excreted into the environment in ever increasing amounts. The xeno-estrogen DDE has been found at high concentrations of 1-5 mg/kg of soil (Aislabie et. al, 1997). These estrogens and xeno-estrogens are having a devastating effect on animal-life, yet little is known or understood on the effects of estrogens on plant-life. Thus it is important to determine what effects (if any) estrogens may have on plants. Other research has shown that estrogen has an effect on plants grown in vitro (Janeczko and Skoczowski, 2005). This research aims to help increase the amount of information on what effects estrogens may have on plants. In this study, the effects of mammalian estrogens (17-β-estradiol, estrone and estriol) on the growth and tuberization of potato plants (Solanum tuberosum L. cv 'Iwa') grown in liquid tissue culture medium are presented. It was found that at even 0.1 mg/L of estrogen, root growth of the plants was diminished and at 10 mg/L of estrogen, plant deformity was apparent and callus growth induced. Acid phosphatase activity of the plants was increased with the addition of 0.1 mg/L and 1 mg/L of estrogen but then decreased with the addition of 10 mg/L of estrogen. Tuber production was slightly reduced in plants treated with estrogen compared to the control.

<p>I developed a precision-cut adrenal slice culture procedure to investigate cytochrome P450 (CYP) catalysed irreversible binding and adrenocorticolytic effects in human, rodent, and fish adrenal tissue, <i>ex vivo</i>. Autoradiography and radioluminography of exposed tissue slices showed that the potent adrenal toxicant 3-methylsulphonyl-2,2´-bis(4-chlorophenyl)-1,1´-dichloroethene (MeSO₂-DDE) causes a selective metabolite binding in <i>zona fasciculata</i> (<i>ZF</i>), which is diminished by the CYP11B1 inhibitor metyrapone. MeSO₂-DDE also reduces corticosterone secretion, increases 11-deoxycorticosterone secretion and causes mitochondrial degeneration in <i>ZF</i> cells in cultured mouse adrenal slices. ACTH treatment of mice induces CYP11B1 and increases irreversible MeSO₂-DDE binding and toxicity in <i>ZF</i> cells. Metyrapone-sensitive binding of MeSO₂-DDE is also observed in human <i>zona fasciculata/reticularis</i> (<i>ZF/ZR</i>) and 11-deoxycorti- sol/corticosterone secretion increases in MeSO₂-DDE-exposed cultured human adrenal slices. The adrenocorticolytic drug 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichlorethane (o,p´- DDD, Mitotane^®) is also bound in <i>ZF/ZR </i>but does not to impair hormone secretion in human adrenal slices at equimolar concentration. A targeted, presumably CYP1B1-catalysed irreversible binding of the adrenocorticolytic carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) in <i>ZF/ZR </i>occurs in rat adrenal slices, whereas presumably CYP1A1-catalysed irreversible binding in endothelial cells is observed in CYP1-induced rats and mice. The rat-specific adrenocorticolytic activity of DMBA may rely on two independent pathological processes resulting in cell death and haemorrhage in the adrenal cortex. In Atlantic cod, selective binding of o,p´-DDD is observed in interrenal cells in cultured anterior kidney slices.</p><p>In conclusion, precision-cut adrenal slice culture is a simple <i>ex vivo</i> test system with which to investigate CYP-catalysed metabolite binding, alteredsteroid hormone secretion and target cell ultrastructure in human, experimental and wild animal tissue. The results imply that organisms under stress could be at increased risk of MeSO₂-DDE induced adrenal toxicity. MeSO₂-DDE is an expected human adrenal toxicant, which should be evaluated as a possible alternative in the therapy of adrenocortical hypersecretion and tumour growth.</p>

I developed a precision-cut adrenal slice culture procedure to investigate cytochrome P450 (CYP) catalysed irreversible binding and adrenocorticolytic effects in human, rodent, and fish adrenal tissue, ex vivo. Autoradiography and radioluminography of exposed tissue slices showed that the potent adrenal toxicant 3-methylsulphonyl-2,2´-bis(4-chlorophenyl)-1,1´-dichloroethene (MeSO2-DDE) causes a selective metabolite binding in zona fasciculata (ZF), which is diminished by the CYP11B1 inhibitor metyrapone. MeSO2-DDE also reduces corticosterone secretion, increases 11-deoxycorticosterone secretion and causes mitochondrial degeneration in ZF cells in cultured mouse adrenal slices. ACTH treatment of mice induces CYP11B1 and increases irreversible MeSO2-DDE binding and toxicity in ZF cells. Metyrapone-sensitive binding of MeSO2-DDE is also observed in human zona fasciculata/reticularis (ZF/ZR) and 11-deoxycorti- sol/corticosterone secretion increases in MeSO2-DDE-exposed cultured human adrenal slices. The adrenocorticolytic drug 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichlorethane (o,p´- DDD, Mitotane®) is also bound in ZF/ZR but does not to impair hormone secretion in human adrenal slices at equimolar concentration. A targeted, presumably CYP1B1-catalysed irreversible binding of the adrenocorticolytic carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) in ZF/ZR occurs in rat adrenal slices, whereas presumably CYP1A1-catalysed irreversible binding in endothelial cells is observed in CYP1-induced rats and mice. The rat-specific adrenocorticolytic activity of DMBA may rely on two independent pathological processes resulting in cell death and haemorrhage in the adrenal cortex. In Atlantic cod, selective binding of o,p´-DDD is observed in interrenal cells in cultured anterior kidney slices. In conclusion, precision-cut adrenal slice culture is a simple ex vivo test system with which to investigate CYP-catalysed metabolite binding, alteredsteroid hormone secretion and target cell ultrastructure in human, experimental and wild animal tissue. The results imply that organisms under stress could be at increased risk of MeSO2-DDE induced adrenal toxicity. MeSO2-DDE is an expected human adrenal toxicant, which should be evaluated as a possible alternative in the therapy of adrenocortical hypersecretion and tumour growth.

The DDT metabolite 3-methylsulfonyl-DDE (3-MeSO2-DDE) is bioactivated by cytochrome P450 11B1 (CYP11B1) in the adrenal cortex of mice and forms irreversibly bound protein adducts, reduces glucocorticoid secretion, and induces cell death selectively in cortisol-producing adrenocortical cells. 3-MeSO2-DDE has therefore been proposed as a lead compound for an improved adrenocortical carcinoma (ACC) therapy. The aims of this thesis were to (1) develop in vitro test systems based on murine and human adrenocortical cell lines and to (2) investigate the mechanisms behind 3-MeSO2-DDE toxicity in adrenocortical cells. The cytotoxic and endocrine-modulating effects of 3-MeSO2-DDE were compared to those of o,p′-DDD (mitotane), the current ACC therapy, and to those of several structurally analogous compounds in both murine and human cell lines. 3-MeSO2-DDE bioactivation and cytotoxicity proceeded in a similar manner in the murine adrenocortical Y-1 cell line as in mice in vivo. The effects were highly structure-specific. Moreover, 3-MeSO2-DDE formed irreversibly bound protein adducts and caused cell death also in the human H295R cell line, and was slightly more cytotoxic than o,p′-DDD. However, 3-MeSO2-DDE toxicity in human cells was not affected by the CYP11B1 inhibitor etomidate, suggesting that bioactivation in human cells is performed by additional/other enzyme(s) than CYP11B1. 3-MeSO2-DDE generated biphasic responses in cortisol and aldosterone secretion and in expression levels of the steroidogenic genes CYP11B1, CYP11B2, and StAR. Such hormesis-like responses were not seen for o,p′-DDD or the precursor DDT metabolite p,p′-DDE. In addition, the two o,p′-DDD enantiomers (R)-(+)-o,p′-DDD and (S)-(-)-o,p′-DDD exhibited slight differences in cytotoxic and endocrine-modulating activity in H295R cells. In conclusion, this thesis  provides  extended  knowledge  on  the  mechanisms  of  action  of 3-MeSO2-DDE and points out important differences in effects between murine and human cells. Lead optimisation studies of 3-MeSO2-DDE using the herein presented in vitro test systems are ongoing.

Mammalian estrogens and estrogen-like compounds known as xeno-estrogens are being found in and excreted into the environment in ever increasing amounts. The xeno-estrogen DDE has been found at high concentrations of 1-5 mg/kg of soil (Aislabie et. al, 1997). These estrogens and xeno-estrogens are having a devastating effect on animal-life, yet little is known or understood on the effects of estrogens on plant-life. Thus it is important to determine what effects (if any) estrogens may have on plants. Other research has shown that estrogen has an effect on plants grown in vitro (Janeczko and Skoczowski, 2005). This research aims to help increase the amount of information on what effects estrogens may have on plants. In this study, the effects of mammalian estrogens (17-β-estradiol, estrone and estriol) on the growth and tuberization of potato plants (Solanum tuberosum L. cv 'Iwa') grown in liquid tissue culture medium are presented. It was found that at even 0.1 mg/L of estrogen, root growth of the plants was diminished and at 10 mg/L of estrogen, plant deformity was apparent and callus growth induced. Acid phosphatase activity of the plants was increased with the addition of 0.1 mg/L and 1 mg/L of estrogen but then decreased with the addition of 10 mg/L of estrogen. Tuber production was slightly reduced in plants treated with estrogen compared to the control.

Mestre -- Escola Nacional de Saude Publica, Rio de Janeiro, 1999.

The DDT metabolite 3-methylsulphonyl-DDE (3-MeSO2-DDE) induces cell death specifically in the adrenal cortex of mice after a cytochrome P45011B1 (CYP11B1)-catalysed bioactivation. This substance is not only an environmental pollutant, but also a suggested lead compound for an improved chemotherapy of adrenocortical carcinoma (ACC). The aim of the thesis was to further investigate this compound in terms of kinetics, cell death mechanisms and species differences. The pharmacokinetics of 3-MeSO2-DDE and the current drug for ACC, o,p’-DDD, was studied during 6 months following a single dose in minipigs. The elimination was slower for 3-MeSO2-DDE than for o,p’-DDD, indicated by a lower clearance and longer t½ in plasma and subcutaneous fat. Both substances remained in fat tissue during the whole study period. Unlike o,p’-DDD, 3-MeSO2-DDE was retained also in liver. The adequacy of the murine adrenocortical cell line Y-1 was evaluated for studies of adrenotoxic compounds. The Y-1 cells proved to be an appropriate test system for future mechanism studies, since CYP-catalysed irreversible binding, inhibited corticosterone production induced by 3-MeSO2-DDE and o,p’-DDD were successfully demonstrated. Cell death of 3-MeSO2-DDE in the mouse adrenal cortex was implied to be necrotic. Early apoptotic signalling (i.e. up-regulation of caspase-9) was observed, although it seemed to be interrupted by ATP-depletion and anti-apoptotic actions by heat shock protein 70, resulting in lack of activation of caspase-3. Using cultured adrenal tissue slices, two not previously studied species were examined ex vivo regarding adrenal binding of 3-MeSO2-[14C]DDE. Binding was found in the hamster adrenal cortex and in assumed cortical cells in the medulla, while the guinea pig adrenal was devoid of binding. This emphasises the species specificity in bioactivation of 3-MeSO2-DDE. The thesis forms a basis for further investigations in the human adrenocortical cell line H295R and provides new knowledge of importance for toxicological risk assessment of 3-MeSO2-DDE.

Notre recherche porte sur la recommandation de nouvelles offres d'emploi venant d'être postées et n'ayant pas d'historique d'interactions (démarrage à froid). Nous adaptons les systèmes de recommandations bien connus dans le domaine du commerce électronique à cet objectif, en exploitant les traces d'usage de l'ensemble des demandeurs d'emploi sur les offres antérieures. Une des spécificités du travail présenté est d'avoir considéré des données réelles, et de s'être attaqué aux défis de l'hétérogénéité et du bruit des documents textuels. La contribution présentée intègre l'information des données collaboratives pour apprendre une nouvelle représentation des documents textes, requise pour effectuer la recommandation dite à froid d'une offre nouvelle. Cette représentation dite latente vise essentiellement à construire une bonne métrique. L'espace de recherche considéré est celui des réseaux neuronaux. Les réseaux neuronaux sont entraînés en définissant deux fonctions de perte. La première cherche à préserver la structure locale des informations collaboratives, en s'inspirant des approches de réduction de dimension non linéaires. La seconde s'inspire des réseaux siamois pour reproduire les similarités issues de la matrice collaborative. Le passage à l'échelle de l'approche et ses performances reposent sur l'échantillonnage des paires d'offres considérées comme similaires. L'intérêt de l'approche proposée est démontrée empiriquement sur les données réelles et propriétaires ainsi que sur le benchmark publique CiteULike. Enfin, l'intérêt de la démarche suivie est attesté par notre participation dans un bon rang au challenge international RecSys 2017 (15/100; un million d'utilisateurs pour un million d'offres). / Our research focuses on the recommendation of new job offers that have just been posted and have no interaction history (cold start). To this objective, we adapt well-knowns recommendations systems in the field of e-commerce by exploiting the record of use of all job seekers on previous offers. One of the specificities of the work presented is to have considered real data, and to have tackled the challenges of heterogeneity and noise of textual documents. The presented contribution integrates the information of the collaborative data to learn a new representation of text documents, which is required to make the so-called cold start recommendation of a new offer. The new representation essentially aims to build a good metric. The search space considered is that of neural networks. Neural networks are trained by defining two loss functions. The first seeks to preserve the local structure of collaborative information, drawing on non-linear dimension reduction approaches. The second is inspired by Siamese networks to reproduce the similarities from the collaborative matrix. The scaling up of the approach and its performance are based on the sampling of pairs of offers considered similar. The interest of the proposed approach is demonstrated empirically on the real and proprietary data as well as on the CiteULike public benchmark. Finally, the interest of the approach followed is attested by our participation in a good rank in the international challenge RecSys 2017 (15/100, with millions of users and millions of offers).

The prevalence of obesity has already epidemic dimensions. Recently, the obesogens have been identified as the main cause in addition to excessive food intake, the lack of physical activity and the genetic background. These substances damage the metabolic processes, interfere with the hormonal functions and impair the energy balance in behalf of gaining weight and obesity. The theoretical part of this work deals with obesity, adipose tissue, lipid droplet and obesogens. From the obesogens there is closely specified a group of persistent organic pollutants (POP) from which one representative was used in the practical part of this work. The aim of the practical part was to describe the cellular model of differentiation the mesenchymal stem cell into adipocytes and to investigate the effect of one of the most frequently occurring obesogen on the expression genes of lipid metabolism and insulin signalling pathway. The morphological changes were observed in cells during differentiation (at days 0, 4, 10 and 21). The mesenchymal cells of the elongated spindle shape changed into adipocytes filled with lipid droplets. Oil Red O staining was used for quantification of accumulated lipids. The differentiation to adipocytes was confirmed by fluorescence immunocytochemistry using a specific protein FABP4. The...

Notre équipe de recherche a récemment développé les premiers inhibiteurs d’une enzyme à DDE, la transposase MOS1, une enzyme analogue à l’intégrase du VIH-1. Ces molécules, de type bisfurylmaléimides, ont également montré une efficacité contre les activités enzymatiques de l’intégrase du VIH. En se basant sur ces résultats, nous avons entrepris la synthèse de nouveaux bisfurylmaléimides dans le but d’identifier de nouveaux inhibiteurs de l’intégrase et de proposer de nouvelles molécules dans la lutte contre le virus responsable du SIDA. L’originalité de notre démarche est l’utilisation de la transposase MOS1 comme modèle pour concevoir nos molécules. Les méthodologies utilisées pour accéder à ces molécules font essentiellement appel à la chimie catalysée par des métaux de transition mais aussi à des réactions de chimie hétérocyclique telles que des réactions de Mitsunobu, de Knoevenagel ou encore de Horner-Wadsworth-Emmons. L’ensemble des molécules synthétisées a fait l’objet d’une évaluation de leurs activités inhibitrices sur la transposase MOS1 et l’intégrase du VIH-1. Leurs propriétés antivirales contre le VIH ont également été évaluées. Parallèlement à ces travaux, nous nous sommes intéressés à la réactivité du noyau maléimide dans des réactions de couplage pallado-catalysées et plus particulièrement dans des couplages de Sonogashira. / Our research team has recently developed the first inhibitors of a DDE enzyme, MOS1 transposase, an enzyme similar to the HIV-1 integrase. These molecules, having a bisfurylmaleimide structure, also showed efficacy against enzymatic activities of HIV integrase. Based on these results, we undertook the synthesis of new bisfurylmaleimides in order to identify new integrase inhibitors and propose new molecules in the fight against the virus that causes AIDS. The originality of our approach is the use of MOS1 transposase as a model for designing our molecules. Methodologies used to access these molecules are essentially involving chemistry catalyzed by transition metals but also reactions of heterocyclic chemistry such as Mitsunobu, Knoevenagel or Horner-Wadsworth-Emmons reactions. All synthesized molecules has been evaluated for their inhibitory activities on the MOS1 transposase and HIV-1 integrase. Their antiviral properties against HIV were also evaluated. Parallel to this work, we investigated the reactivity of the maleimide core in palladium-catalyzed cross-coupling reactions especially in Sonogashira couplings.