240 research outputs found
Generation of human-like motion on anthropomorphic systems using inverse dynamics
This work deals with the generation of human-like
whole-body movements on anthropomorphic
systems. We propose a general framework to
generate robot movements from the definition of
ordered stack of tasks and a global resolution
scheme that enables to consider different kinds of
constraints. We compare qualitatively the robot
movements generated from this software with
similar recorded human movements. We start with a
direct global comparison of body movements. Then
we analyze the magnitude of the reconstructed
human torques and compare with the simulated
robot torques during the motion
Identification des dermatophytes par spectrométrie de masse MALDI-TOF
Introduction
L’identification des dermatophytes par les méthodes microbiologiques conventionnelles est souvent longue et fastidieuse. La technique de spectrométrie de masse et sa variante MALDI-TOF (Matrix Assisted Laser Desorption Ionisation-Time of Flight) est un nouvel outil utilisé pour l’identification des bactéries et des levures dans les laboratoires d’analyses médicales. Nous avons récemment développé une méthode standardisée pour l’identification en routine des champignons filamenteux à partir de culture en milieu solide. L’objectif de cette étude est d’étendre cette méthode standardisée à l’identification des dermatophytes dans l’activité de routine du laboratoire.
Matériel et méthode
Une banque de référence contenant les spectres de masse de 44 souches parfaitement caractérisées correspondants à 13 espèces de dermatophytes a été générée sur un UltraFlex (BruckerDaltonics, Allemagne) couplé au logiciel MaldiBiotyper v2.1. Par la suite, 133 souches isolées de prélèvements cliniques ont été identifiées en comparant leur spectre à ceux inclus dans la banque de référence : l’identification d’espèce a été retenue si le Log Score (LS) obtenu était supérieur ou égal à 1,7. Enfin, l’identification par MALDI-TOF a été considérée comme correcte en cas de concordance avec l’identification morphologique ou moléculaire des isolats cliniques.
RĂ©sultats
L’identification par spectrométrie de masse(SM) a été correcte pour 130 (97,8 %) des isolats. Pour 2 isolats identifiés conventionnellement comme Microsporum canis, l’identification par SM n’a pas pu générer de spectre avec un LS valide. Pour un isolat correspondant à Microsporum audouinii, la SM a généré une mauvaise identification. Tous les isolats ont pu être identifiés après seulement 3 à 6 jours de culture avant l’apparition des caractères morphologiques conventionnels d’identification.
Conclusion
Le protocole de SM utilisé pour l’identification des champignons filamenteux au laboratoire est applicable aux dermatophytes. Une identification d’espèce peut être obtenue en 3 à 6 jours alors qu’une identification conventionnelle qui nécessite notamment des milieux de cultures complémentaires demande 2 à 3 semaines
Altered Protein Networks and Cellular Pathways in Severe West Nile Disease in Mice
Background:The recent West Nile virus (WNV) outbreaks in developed countries, including Europe and the United States, have been associated with significantly higher neuropathology incidence and mortality rate than previously documented. The changing epidemiology, the constant risk of (re-)emergence of more virulent WNV strains, and the lack of effective human antiviral therapy or vaccines makes understanding the pathogenesis of severe disease a priority. Thus, to gain insight into the pathophysiological processes in severe WNV infection, a kinetic analysis of protein expression profiles in the brain of WNV-infected mice was conducted using samples prior to and after the onset of clinical sympt
Low expression of bcl-2 in Brca1-associated breast cancers
Little data are available concerning the molecular mechanisms of action of Brca1 and Brca2 in breast oncogenesis. Recent experimental results suggest that Brca1 plays a role in the regulation of apoptosis. In order to determine whether the analysis of human tumours would provide data supporting this hypothesis, we have assessed the expression of the antiapoptotic bcl-2 and of the proapoptotic p53 genes in Brca1- and Brca2-associated breast carcinomas. The levels of expression of these genes were compared to those observed in controls and to the mitotic and the apoptotic indexes. Our series were composed of 16 cases of breast carcinoma in women with a germline Brca1 gene mutation, and of four cases with Brca2 mutation. A group of 39 patients aged under 36 years and for whom the search for Brca1 gene mutations was negative, and a group of 36 cases of sporadic cancers without data on their Brca status were used as controls. Immunohistochemistry was used to detect p53 and bcl-2 gene products. Mitotic and apoptotic indexes were higher in Brca1-associated tumours than in controls. No significant difference in p53 immunostaining was observed between the four groups of patients. In contrast, the rate of bcl-2-positive tumours was lower (31%) in Brca1-carcinomas than in carcinomas without Brca1 mutation (90%) (P< 10–3). A strong Bcl-2 expression was found in the four cases of Brca2-associated carcinomas. No significant correlation was observed between p53 and Bcl-2 immunostainings, either in cases or in controls. The association between Brca1 status and Bcl-2 expression remained significant after adjustment for the oestrogen receptor status. Our study shows that a low expression of bcl-2 characterises most Brca1-associated breast carcinomas, a biological trait which seems not to be shared by Brca2-associated tumours nor to be related to oestrogen receptor and/or p53 status.bcl-2 might thus be one of the target genes involved in the oncogenesis related to Brca1 and its down-regulation may account for the increased apoptosis and the high proliferative rate observed in Brca1-associated carcinomas. © 2000 Cancer Research Campaig
The First Genomic and Proteomic Characterization of a Deep-Sea Sulfate Reducer: Insights into the Piezophilic Lifestyle of Desulfovibrio piezophilus
Desulfovibrio piezophilus strain C1TLV30T is a piezophilic anaerobe that was isolated from wood falls in the Mediterranean deep-sea. D. piezophilus represents a unique model for studying the adaptation of sulfate-reducing bacteria to hydrostatic pressure. Here, we report the 3.6 Mbp genome sequence of this piezophilic bacterium. An analysis of the genome revealed the presence of seven genomic islands as well as gene clusters that are most likely linked to life at a high hydrostatic pressure. Comparative genomics and differential proteomics identified the transport of solutes and amino acids as well as amino acid metabolism as major cellular processes for the adaptation of this bacterium to hydrostatic pressure. In addition, the proteome profiles showed that the abundance of key enzymes that are involved in sulfate reduction was dependent on hydrostatic pressure. A comparative analysis of orthologs from the non-piezophilic marine bacterium D. salexigens and D. piezophilus identified aspartic acid, glutamic acid, lysine, asparagine, serine and tyrosine as the amino acids preferentially replaced by arginine, histidine, alanine and threonine in the piezophilic strain. This work reveals the adaptation strategies developed by a sulfate reducer to a deep-sea lifestyle
Mammary Paget's disease occurring after mastectomy
BACKGROUND: Mammary Paget's disease and extramammary Paget's disease are neoplastic conditions, in which there is intraepithelial (usually intraepidermal) infiltration by neoplastic cells showing glandular differentiation. Mammary Paget's disease occurs exclusively on the nipple/areola complex from where it may spread to the surrounding skin. CASE PRESENTATION: We here describe a case of Paget's disease occurring on the thoracic wall site of a previous simple mastectomy, and also briefly summarise the most important aspects leading to a diagnosis of mammary Paget's disease. CONCLUSION: To the best of our knowledge, this is the first reported case of mammary Paget's disease occurring after mastectomy. The absence of the nipple/areola complex obviously raised some questions concerning whether it was mammary or extra-mammary Paget's disease, and how it could occur in the absence of the nipple/areola complex
Fungal colonization in Cystic Fibrosis (CF): Epidemiology and antifungal resistance in a French cohort of CF patients – Focused on Aspergillus fumigatus colonization
Introduction:
Cystic fibrosis (CF) is the major genetic inherited disease in the European Caucasian population, with an average of 1 in 3000 living births in France. Prognostic depend
essentially on the lung impairments. While considerable attention therefore has been paid over recent decades to prevent and treat bacterial respiratory infections, we observed emergence of fungi colonization in CF respiratory tract. In particular, Aspergillus fumigatus represents the most common causative agent colonizing the airways of CF patients; it can be responsible for Allergic Bronchopulmonary Aspergillosis (ABPA). Since oral corticosteroids and itraconazole represent the mainstay of ABPA treatment, long-term therapy may increase the risk of acquired resistance to azoles that is mainly associated with amino acid substitutions in the CYP51A gene of A. fumigatus.
Objective:
First, we managed to have exhaustive epidemiological data on species of filamentous fungi able to colonize the airway tract of 300 CF patients followed-up in our national prospective study ("MucoFong" study – PHRC1902). Second, CF patients being chronically exposed to azole (especially to itraconazole), our study aimed to evaluate the prevalence of azole resistance in isolates prospectively collected from CF patients followed-up in seven French hospitals involved in our national prospective study. Third, we focused on the most prevalent species: Aspergillus fumigatus, studying the azole resistance at molecular level. To our knowledge, it is the first multicenter study focused on azole resistance of A. fumigatus in CF.
Methods:
A total of 243 sputa were analyzed using the same protocol in each centre. The
MICs of antifungal drugs were evaluated for each isolate using the E-test ® strips. Focusing on A. fumigatus, a total of 87 isolates was collected in 85 patients. These isolates were characterized at the molecular level by targeting ITS, ß-tubulin and MAT-A/α genes. The CYP51A gene as well as its promoter was sequenced; a 3D Cyp51A protein homology model was built.
Results and discussion:
300 patients were enrolled in this study. At inclusion time, most of them were adults colonized with A. fumigatus (about 35% of the patients). Scedosporium was isolated in 5%, and Exophiala in about 2%. Regarding antifungal susceptibility, isolates of Scedosporium and Exophiala exhibited antifungal resistance comparable with published data. Regarding A. fumigatus, a majority of isolates (88.1%) were found sensitive to itraconazole (MIC≤ 2μg/ml), and 2 new mutations were identified and localized within 3-dimensional Cyp51A protein model. To obtain insight into azole resistance of A. fumigatus, the results are analyzed taking into account clinical data, itraconazole exposition, and the potential correlation between the identified CYP5IA mutations and azole resistance is discussed based on the Cyp51A protein homology model
Preoperative breast radiation therapy: Indications and perspectives.
Preoperative breast radiation therapy (RT) is not a new concept, but older studies failed to change practice. More recently, there has been interest in revisiting preoperative RT using modern techniques. This current perspective discusses the indications, summarises the published literature and then highlights current clinical trials, with particular attention to combining with novel drugs and optimising associated translational research
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