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Brest, France

Quellec G.,French Institute of Health and Medical Research | Charriere K.,French Institute of Health and Medical Research | Lamard M.,Telecom Bretagne | Cochener B.,University of Western Brittany | Cazuguel G.,CHRU Brest
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014 | Year: 2014

Anterior eye segment surgeries are usually video-recorded. If we are able to efficiently analyze surgical videos in real-time, new decision support tools will emerge. The main anatomical landmarks in these videos are the pupil boundaries and the limbus, but segmenting them is challenging due to the variety of colors and textures in the pupil, the iris, the sclera and the lids. In this paper, we present a solution to reliably normalize the center and the scale in videos, without explicitly segmenting these landmarks. First, a robust solution to track the pupil center is presented: it uses the fact that the pupil boundaries, the limbus and the sclera / lid interface are concentric. Second, a solution to estimate the zoom level is presented: it relies on the illumination pattern reflected on the cornea. The proposed solution was assessed in a dataset of 186 real-live cataract surgery videos. The distance between the true and estimated pupil centers was equal to 8.0 ± 6.9% of the limbus radius. The correlation between the estimated zoom level and the true limbus size in images was high: R = 0.834. © 2014 IEEE. Source

Bouzid D.,French Institute of Health and Medical Research | Bert J.,French Institute of Health and Medical Research | Dupre P.-F.,CHRU Brest | Benhalouche S.,French Institute of Health and Medical Research | And 3 more authors.
Acta Oncologica | Year: 2015

Intraoperative radiotherapy (IORT) is continuously gaining ground in cancer treatment. However, there is currently no planning system associated with these devices, which precludes patient-specific dose delivery optimization. The objective of this study was the development and validation of a Monte Carlo simulation (MCS)-based dosimetry platform using the Intrabeam™ system.Methods. After surgical resection of the tumor this system delivers a single dose fraction at the surface of an applicator irradiating the tumor bed through a 50 kV x-ray beam. The GATE MCS platform was used in this study combining the phase space obtained by modeling the x-ray source and the detailed modeling of the additional parts of the Intrabeam™ system. The model was validated by comparing simulated versus experimental measurements of depth dose curves (DDC) and isotropy. A clinical validation study was also carried out using patient computed tomography images.Results. The mean deviation between measured and simulated DDC was 2.9% ± 4.4% and 5.9% ± 5.7% for the bare needle and the use of applicators, respectively. A good agreement with experimental measurements was also found in terms of dose isotropy with a maximum difference of 2.04% for the 40 mm diameter applicator. A patient study revealed a mean absolute deviation of 0.06 Gy between simulated and thermoluminescent dosimeters (TLD) measured skin doses.Conclusion. This study shows the potential of using the GATE MCS platform to model three-dimensional dose distributions of the Intrabeam™ system for use in IORT. © 2015 © 2015 Informa Healthcare. Source

Menn B.,Neurokin S.a. | Bach S.,French National Center for Scientific Research | Blevins T.L.,Efficacy Pharmacology MDS Pharma Services | Campbell M.,Efficacy Pharmacology MDS Pharma Services | And 2 more authors.
PLoS ONE | Year: 2010

Background: Although quite challenging, neuroprotective therapies in ischemic stroke remain an interesting strategy to counter mechanisms of ischemic injury and reduce brain tissue damage. Among potential neuroprotective drug, cyclin-dependent kinases (CDK) inhibitors represent interesting therapeutic candidates. Increasing evidence indisputably links cell cycle CDKs and CDK5 to the pathogenesis of stroke. Although recent studies have demonstrated promising neuroprotective efficacies of pharmacological CDK inhibitors in related animal models, none of them were however clinically relevant to human treatment. Methodology/Principal Findings: In the present study, we report that systemic delivery of (S)-roscovitine, a well known inhibitor of mitotic CDKs and CDK5, was neuroprotective in a dose-dependent manner in two models of focal ischemia, as recommended by STAIR guidelines. We show that (S)-roscovitine was able to cross the blood brain barrier. (S)-roscovitine significant in vivo positive effect remained when the compound was systemically administered 2 hrs after the insult. Moreover, we validate one of (S)-roscovitine in vivo target after ischemia. Cerebral increase of CDK5/p25 activity was observed 3 hrs after the insult and prevented by systemic (S)-roscovitine administration. Our results show therefore that roscovitine protects in vivo neurons possibly through CDK5 dependent mechanisms. Conclusions/Significance: Altogether, our data bring new evidences for the further development of pharmacological CDK inhibitors in stroke therapy. © 2010 Menn et al. Source

Le Calloch R.,CHRU Brest
BMJ case reports | Year: 2013

Aplastic anaemia is a rare and serious disease characterised by severe immunosuppression due to prolonged neutropenia and the use of immunosuppressants such as corticosteroids, cyclosporine and antithymocyte globulin. Candida species are pathogens of low virulence colonising the skin and the digestive tract of many healthy individuals. Nonetheless, the incidence of invasive candidal infection is increasing. The widespread use of central intravascular catheters, invasive procedures, broad-spectrum antibiotics and immunosuppresion predisposes patients to these infections. Eye, skin, cardiac, liver, spleen and brain infection are the most common sites of invasive candidiasis. Bone and joint infections are less frequent and Candida hip septic arthritis is extremely rare. We present here a patient treated for aplastic anaemia, who developed fungal arthritis of the hip and systemic candidaemia. Source

Boisrame-Gastrin S.,University of Western Brittany | Boisrame-Gastrin S.,Brest University Hospital Center | Tande D.,University of Western Brittany | Munck M.,CHRU Brest | And 3 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2011

Objectives: Salmonella spp. are among the most frequently encountered bacterial pathogens in children adopted abroad, especially from developing countries. The aim of this study was to investigate the carriage of Salmonella in international adoptees over an 84 month period. This screening programme was initiated after serious infections occurred in adopted children. Material and methods: Stool samples taken at the first visit to the outpatient adoption practice and subsequently every month from children adopted from an orphanage in Bamako (Mali) and from all members of their adoptive families were screened for Salmonella. Bacteria were characterized by standard biochemical methods, serotyping, disc diffusion antibiograms and PFGE. β-Lactamase genes were sought by PCR. Results: Over the study period, 55 families that adopted 61 children from the state orphanage of Bamako were surveyed. Ninety-two Salmonella spp. were isolated from faecal samples from 30 families that had adopted a child. The isolates were all identified as Salmonella enterica of different serovars, Babelsberg and Enteritidis being the most prevalent. PFGE classified the Salmonella isolates into nine genotypic profiles matching with their serovar. Of the 41 non-duplicate isolates, 8 were susceptible to all tested antibiotics and 26 Salmonella isolates produced an extended-spectrum β-lactamase (ESBL). PCR and DNA sequencing revealed that all the ESBL-producing isolates harboured the bla TEM-1 gene, 21 isolates harboured in addition the bla SHV-12 gene and the 5 remaining isolates harboured the bla CTX-M-15 gene. Conclusions: International adoption may contribute to the global emergence and spread of multidrug-resistant Salmonella. © The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. Source

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