Anticorps monovalents modifiés anti-CA 125 nouveaux inhibiteurs de l'antigène tumoral CA 125

CA 125 est un déterminant antigénique reconnu par l'anticorps monoclonal OC125. Une surexpression de la glycoprotéine CA 125 au niveau de la surface des ovaires est observée dans plus de 90% des cancers ovariens séreux, mais n'est pas détectable dans les tissus ovariens normaux. Il s'agit d'une glycoprotéine, membre de la famille des mucines ayant un poids moléculaire supérieur à 200 kDa. Malgré des recherches intensives, la fonction de cet antigène tumoral demeure inconnue à cause de difficultés à isoler et à cloner les séquences codantes. Dans l'optique d'étudier CA 125 et ses rôles possibles dans le développement du cancer ovarien, nous avons généré les premiers inhibiteurs de CA 125. Ces inhibiteurs consistent en des anticorps monovalents modifiés (scFv) dérivés des anticorps monoclonaux OC125 et VK-8 qui sont spécifiques à CA 125 et qui reconnaissent deux épitopes différents. Les librairies de scFvs ont été criblées par ELISA pour la liaison à CA 125. Un scFv dérivant de chacune des librairies, OC125 #3:11 et VK-8 #1:9, a été sélectionné pour la suite de l'étude."--Résumé abrégé par UMI

The impact of the open and closed exhibit designs on captive Bennett's wallaby (Macropus rufogriseus) behaviour and visitor experience

Zoo research on exhibit designs has made notable progress in the past decades. A great challenge zoo exhibit designers are faced with today is finding exhibit designs that optimize both animal welfare and visitor experience. In the present research, the impacts of exhibit design on Bennett’s wallaby behaviour and on visitor experience were studied. Data collected from two open design exhibits, allowing physical interaction between visitors and animals, were compared to observations from two closed exhibit designs, where no physical human-animal interaction was possible. Wallaby behavioural data were collected using the focal sampling method for activity budget observations and the scan sampling method for spatial distribution observations. Moreover, visitor experience data were collected using survey-type questionnaires that were randomly distributed to zoo visitors. Our study revealed that, when compared to more traditional closed designs, open exhibit designs increase overall visitor experience and positively benefit visitor perception. Additionally, our results showed that feeding and interactive behaviours were significantly higher in closed exhibit designs but functional use of space was similar in both exhibit design types. Although some behaviours did significantly differ between habitat designs, they did not provide sufficient evidence for major exhibit design impacts on wallaby welfare. However, possible visitor effects on Bennett’s wallaby activity budgets and space use was discussed. Our results suggest that the open exhibit design is a good option for optimizing visitor experience without affecting animal welfare, but we recommend continued research to more fully understand the impacts of different exhibit designs on the behaviour and welfare of captive Bennett’s wallabies

Uncovering the Prevalence and Diversity of Integrating Conjugative Elements in Actinobacteria

Horizontal gene transfer greatly facilitates rapid genetic adaptation of bacteria to shifts in environmental conditions and colonization of new niches by allowing one-step acquisition of novel functions. Conjugation is a major mechanism of horizontal gene transfer mediated by conjugative plasmids and integrating conjugative elements (ICEs). While in most bacterial conjugative systems DNA translocation requires the assembly of a complex type IV secretion system (T4SS), in Actinobacteria a single DNA FtsK/SpoIIIE-like translocation protein is required. To date, the role and diversity of ICEs in Actinobacteria have received little attention. Putative ICEs were searched for in 275 genomes of Actinobacteria using HMM-profiles of proteins involved in ICE maintenance and transfer. These exhaustive analyses revealed 144 putative FtsK/SpoIIIE-type ICEs and 17 putative T4SS-type ICEs. Grouping of the ICEs based on the phylogenetic analyses of maintenance and transfer proteins revealed extensive exchanges between different sub-families of ICEs. 17 ICEs were found in Actinobacteria from the genus Frankia, globally important nitrogen-fixing microorganisms that establish root nodule symbioses with actinorhizal plants. Structural analysis of ICEs from Frankia revealed their unexpected diversity and a vast array of predicted adaptive functions. Frankia ICEs were found to excise by site-specific recombination from their host's chromosome in vitro and in planta suggesting that they are functional mobile elements whether Frankiae live as soil saprophytes or plant endosymbionts. Phylogenetic analyses of proteins involved in ICEs maintenance and transfer suggests that active exchange between ICEs cargo-borne and chromosomal genes took place within the Actinomycetales order. Functionality of Frankia ICEs in vitro as well as in planta lets us anticipate that conjugation and ICEs could allow the development of genetic manipulation tools for this challenging microorganism and for many other Actinobacteria

Anticorps monovalents modifiés anti-CA 125 nouveaux inhibiteurs de l'antigène tumoral CA 125

CA 125 est un déterminant antigénique reconnu par l'anticorps monoclonal OC125. Une surexpression de la glycoprotéine CA 125 au niveau de la surface des ovaires est observée dans plus de 90% des cancers ovariens séreux, mais n'est pas détectable dans les tissus ovariens normaux. Il s'agit d'une glycoprotéine, membre de la famille des mucines ayant un poids moléculaire supérieur à 200 kDa. Malgré des recherches intensives, la fonction de cet antigène tumoral demeure inconnue à cause de difficultés à isoler et à cloner les séquences codantes. Dans l'optique d'étudier CA 125 et ses rôles possibles dans le développement du cancer ovarien, nous avons généré les premiers inhibiteurs de CA 125. Ces inhibiteurs consistent en des anticorps monovalents modifiés (scFv) dérivés des anticorps monoclonaux OC125 et VK-8 qui sont spécifiques à CA 125 et qui reconnaissent deux épitopes différents. Les librairies de scFvs ont été criblées par ELISA pour la liaison à CA 125. Un scFv dérivant de chacune des librairies, OC125 #3:11 et VK-8 #1:9, a été sélectionné pour la suite de l'étude."--Résumé abrégé par UMI

Differences in elemental composition of tailings, soils, and plant tissues following five decades of native plant colonization on a gold mine site in Northwestern Québec

International audienc