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Saint-André-lez-Lille, France

Martinez A.,University of Lille Nord de France | Martinez A.,French Institute of Health and Medical Research | Martinez A.,Institute Pasteur Of Lille | Martinez A.,Udsl University Droit Et Sante Of Lille | And 25 more authors.
PLoS ONE | Year: 2011

Once regarded as an AIDS-defining illness, Pneumocystis pneumonia (PcP) is nowadays prevailing in immunocompromised HIV-negative individuals such as patients receiving immunosuppressive therapies or affected by primary immunodeficiency. Moreover, Pneumocystis clinical spectrum is broadening to non-severely-immunocompromised subjects who could be colonized by the fungus while remaining asymptomatic for PcP, thus being able to transmit the infection by airborne route to susceptible hosts. Although the taxonomical position of the Pneumocystis genus has been clarified, several aspects of its life cycle remain elusive such as its mode of proliferation within the alveolus or its ploidy level. As no long-term culture model exists to grow Pneumocystis organisms in vitro, an option was to use a model of immunosuppressed rat infected with Pneumocystis carinii and sort life cycle stage fractions using a high-through-put cytometer. Subsequently, ploidy levels of the P. carinii trophic and cystic form fractions were measured by flow cytometry. In the cystic form, eight contents of DNA were measured thus strengthening the fact that each mature cyst contains eight haploid spores. Following release, each spore evolves into a trophic form. The majority of the trophic form fraction was haploid in our study. Some less abundant trophic forms displayed two contents of DNA indicating that they could undergo (i) mating/fusion leading to a diploid status or (ii) asexual mitotic division or (iii) both. Even less abundant trophic forms with four contents of DNA were suggestive of mitotic divisions occurring following mating in diploid trophic forms. Of interest, was the presence of trophic forms with three contents of DNA, an unusual finding that could be related to asymmetrical mitotic divisions occurring in other fungal species to create genetic diversity at lower energetic expenses than mating. Overall, ploidy data of P. carinii life cycle stages shed new light on the complexity of its modes of proliferation. © 2011 Martinez et al. Source

Garraux G.,University of Liege | Phillips C.,University of Liege | Schrouff J.,University of Liege | Kreisler A.,University of Lille Nord de France | And 13 more authors.
NeuroImage: Clinical | Year: 2013

Most available pattern recognition methods in neuroimaging address binary classification problems. Here, we used relevance vector machine (RVM) in combination with booststrap resampling ('bagging') for non-hierarchical multiclass classification. The method was tested on 120 cerebral 18fluorodeoxyglucose (FDG) positron emission tomography (PET) scans performed in patients who exhibited parkinsonian clinical features for 3.5 years on average but that were outside the prevailing perception for Parkinson's disease (PD). A radiological diagnosis of PD was suggested for 30 patients at the time of PET imaging. However, at follow-up several years after PET imaging, 42 of them finally received a clinical diagnosis of PD. The remaining 78 APS patients were diagnosed with multiple system atrophy (MSA, N = 31), progressive supranuclear palsy (PSP, N = 26) and corticobasal syndrome (CBS, N = 21), respectively. With respect to this standard of truth, classification sensitivity, specificity, positive and negative predictive values for PD were 93% 83% 75% and 96%, respectively using binary RVM (PD vs. APS) and 90%, 87%, 79% and 94%, respectively, using multiclass RVM (PD vs. MSA vs. PSP vs. CBS). Multiclass RVM achieved 45%, 55% and 62% classification accuracy for, MSA, PSP and CBS, respectively. Finally, a majority confidence ratio was computed for each scan on the basis of class pairs that were the most frequently assigned by RVM. Altogether, the results suggest that automatic multiclass RVM classification of FDG PET scans achieves adequate performance for the early differentiation between PD and APS on the basis of cerebral FDG uptake patterns when the clinical diagnosis is felt uncertain. This approach cannot be recommended yet as an aid for distinction between the three APS classes under consideration. © 2013 The Authors. Source

Pruvost I.,University of Lille Nord de France | Pruvost I.,Lille University Hospital Center | Pruvost I.,Udsl University Droit Et Sante Of Lille | Lowingerova-Fauvet S.,University of Lille Nord de France | And 10 more authors.
Archives de Pediatrie | Year: 2012

Objective: To assess the levels of primary care physicians' adherence to the 2010 French vaccination schedule against pertussis, measles-mumps-rubella (MMR), and pneumococcal infections in northern France. Methods: Two hundred forty-nine primary care physicians were questioned over the phone from February 15th to May 27th 2010. Results: The total response rate was 61% (n=152): 43 pediatricians and 109 general practitioners (GPs). The conjugated pneumococcal vaccination was routinely proposed by 93% of the physicians (100% of the pediatricians and 90% of the GPs, P=0.02), and the recommended immunization schedule was correctly stated by 98% of the pediatricians and 70% of the GPs, P< 0.001. While the pertussis vaccination was proposed by all the physicians, the recommended immunization schedule was correctly followed in only 46% of the cases (there was no significant difference between the 2 groups of physicians). As for the MMR vaccination, 1 physician did not propose it; 27% had correct knowledge about the MMR vaccination schedule (44% of the pediatricians and 20% of the GPs, P< 0.01); 39% initiated an early MMR vaccination schedule for children in day care centers. The main source of their information was medical representatives of pharmaceutical companies, medical journals, and to a lesser degree, weekly epidemiological bulletins and continuing medical education meetings. Conclusion: The level of physicians' knowledge about the vaccination schedule in children was insufficient in northern France, especially for pertussis and measles. This can decrease vaccination coverage levels as well as its beneficial effects for children. © 2012 Elsevier Masson SAS. Source

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