Articles of the day

Epithelial cell adhesion molecule is a prognosis marker for intrahepatic cholangiocarcinoma.

K.Boudjema , B.Turlin , B.Meunier , M.Rayar , L.Sulpice , M.Desille , P.Bellaud , B.Clement , C.Coulouarn , E.Boucher


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BACKGROUND: Recently, we identified a gene signature of intrahepatic cholangiocarcinoma stroma and demonstrated its clinical relevance for prognosis. The most upregulated genes included epithelial cell adhesion molecule , a biomarker of cancer stem cells. We hypothesized that CSC biomarkers could predict recurrence of resected ICC. METHODS: Both functional analysis of the stroma signature previously obtained and immunohistochemistry of 40 resected ICC were performed. The relationships between the expression of CSC markers and clinicopathologic factors including survival were assessed by univariate and multivariable analyzes. RESULTS: Gene expression profile of the stroma of ICC highlighted embryonic stem cells signature. Immunohistochemistry on tissue microarray showed at a protein level the increased expression of CSC biomarkers in the stroma of ICC compared with nontumor fibrous liver tissue. The overexpression of EpCAM in the stroma of ICC is an independent risk factor for overall and disease-free survival. In addition, the overexpression of EpCAM in nontumor fibrous liver tissue is closely correlated with a worst disease-free survival. CONCLUSIONS: Our findings provide new arguments for a potential role of CSC on ICC progression supporting the idea that targeting CSC biomarkers might represent a promise personalized treatment.

Simplification of visual rendering in simulated prosthetic vision facilitates navigation

V.Vergnieux , M.Mace , C.Jouffrais


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Visual neuroprostheses are yet limited and Simulated Prosthetic Vision is used to evaluate potential and forthcoming functionality of these implants. SPV has been used to evaluate the minimum requirement on visual neuroprostheses characteristics to restore various functions such as reading, objects and face recognition, objects grasping, etc. Some of these studies focused on obstacle avoidance but only a few investigated orientation or navigation abilities with prosthetic vision. The resolution of current arrays of electrodes is not sufficient to allow navigation tasks without additional processing of the visual input. In this study, we simulated a low resolution array and evaluated the navigation abilities restored when visual information was processed with various computer vision algorithms to enhance the visual rendering. Three main visual rendering strategies were compared to a control rendering in a wayfinding task within an unknown environment. The control rendering corresponded to a resizing of the original image onto the electrode array size, according to the average brightness of the pixels. In the first rendering strategy, vision distance was limited to three, six or nine meters respectively. In the second strategy, the rendering was not based on the brightness of the image pixels, but on the distance between the user and the elements in the field of view. In the last rendering strategy, only the edges of the environments were displayed, similar to a wireframe rendering. All the tested renderings, except the 3 m limitation of the field of view, improved navigation performance and decreased cognitive load. Interestingly, the distance-based and wireframe renderings also improved the cognitive mapping of the unknown environment. These results show that low resolution implants are usable for wayfinding if specific computer vision algorithms are used to select and display appropriate information regarding the environment.

Analysis of Novel Mycobacteriophages Indicates the Existence of Different Strategies for Phage Inheritance in Mycobacteria

S.Emma , F.Jorgelina , T.Sabrina , M.Héctor


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Mycobacteriophages have been essential in the development of mycobacterial genetics through their use in the construction of tools for genetic manipulation. Due to the simplicity of their isolation and variety of exploitable molecular features, we searched for and isolated 18 novel mycobacteriophages from environmental samples collected from several geographic locations. Characterization of these phages did not differ from most of the previously described ones in the predominant physical features (virion size in the 100?400 nm, genome size in the 50?70 kbp, morphological features compatible with those corresponding to the Siphoviridae family), however novel characteristics for propagation were noticed. Although all the mycobacteriophages propagated at 30uC, eight of them failed to propagate at 37uC. Since some of our phages yielded pinpoint plaques, we improved plaque detection by including sub-inhibitory concentrations of isoniazid or ampicillin-sulbactam in the culture medium. Thus, searches for novel mycobacteriophages at low temperature and in the presence of these drugs would allow for the isolation of novel members that would otherwise not be detected. Importantly, while eight phages lysogenized Mycobacterium smegmatis, four of them were also capable of lysogenizing Mycobacterium tuberculosis. Analysis of the complete genome sequence obtained for twelve mycobacteriophages (the remaining six rendered partial genomic sequences) allowed for the identification of a new singleton. Surprisingly, sequence analysis revealed the presence of parA or parA/parB genes in 7/18 phages including four that behaved as temperate in M. tuberculosis. In summary, we report here the isolation and preliminary characterization of mycobacteriophages that bring new information to the field.Fil: Stella, Emma Julieta. Universidad Nacional de Rosario. Facultad de Cs.medicas. Escuela de Cs.medicas. Cat.de Microbiologia,parasitologia y Virologia;Fil: Franceschelli, Jorgelina Judith. Universidad Nacional de Rosario. Facultad de Cs.medicas. Escuela de Cs.medicas. Cat.de Microbiologia,parasitologia y Virologia;Fil: Tasselli, Sabrina Emilse. Universidad Nacional de Rosario. Facultad de Cs.medicas. Escuela de Cs.medicas. Cat.de Microbiologia,parasitologia y Virologia;Fil: Morbidoni, Héctor Ricardo. Universidad Nacional de Rosario. Facultad de Cs.medicas. Escuela de Cs.medicas. Cat.de Microbiologia,parasitologia y Virologia
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