96 research outputs found
The DmsABC Sulfoxide Reductase Supports Virulence in Non-typeable Haemophilus influenzae.
Although molybdenum-containing enzymes are well-established as having a key role in bacterial respiration, it is increasingly recognized that some may also support bacterial virulence. Here, we show that DmsABC, a putative dimethylsulfoxide (DMSO) reductase, is required for fitness of the respiratory pathogen Haemophilus influenzae (Hi) in different models of infection. Expression of the dmsABC operon increased with decreasing oxygen availability, but despite this, a Hi2019Δd msA strain did not show any defects in anaerobic growth on chemically defined medium (CDM), and viability was also unaffected. Although Hi2019Δd msA exhibited increased biofilm formation in vitro and greater resistance to hypochlorite killing compared to the isogenic wild-type strain, its survival in contact with primary human neutrophils, in infections of cultured tissue cells, or in a mouse model of lung infection was reduced compared to Hi2019WT. The tissue cell infection model revealed a two-fold decrease in intracellular survival, while in the mouse model of lung infection Hi2019Δd msA was strongly attenuated and below detection levels at 48 h post-inoculation. While Hi2019WT was recovered in approximately equal numbers from bronchoalveolar lavage fluid (BALF) and lung tissue, survival of Hi2019Δd msA was reduced in lung tissue compared to BALF samples, indicating that Hi2019Δd msA had reduced access to or survival in the intracellular niche. Our data clearly indicate for the first time a role for DmsABC in H. influenzae infection and that the conditions under which DmsABC is required in this bacterium are closely linked to interactions with the host
Applying MDA and OMG Robotic Specification for Developing Robotic Systems
Robotics systems have special needs often related with their realtime nature and environmental properties. Often, control and communication paths within the system are tightly coupled to the actual physical configuration of the robot. As a consequence, these robots can only be assembled, configured, and programmed by robot experts. Traditional approaches, based on mainly writing the code without using software engineering techniques, are still used in the development process of these systems. Even when these robotic systems are successfully used, several problems can be identified and it is widely accepted that new approaches should be explored. The contribution of this research consists in delineating guidelines for the construction of robotic software systems, taking advantage of the application of the OMG standard robotic specifications which adhere to the model-driven approach MDA. Thereby the expert knowledge is captured in standard abstract models that can then be reused by other less experienced developers. In addition part of the code is automatically generated, reducing costs and improving quality
A case of coexisting Warthin tumor and langerhans cell histiocytosis associated with necrosis, eosinophilic abscesses and a granulomatous reaction in intraparotid lymph nodes
We present a patient (50-year-old male) with coexisting Warthin tumor and involvement of two intraparotid lymph nodes by Langerhans cell histiocytosis associated with necrosis, eosinophilic abscesses and a granulomatous reaction. This is the second documented case of this unusual combination of histological changes in nodal Langerhans cell histiocytosis and the first case involving intraparotid lymph nodes occurring together with an ipsilateral Warthin tumor
Robotic Engineer’s Specifications for a Well-Fitted Model-Driven Control Architecture for Robots
Preliminary Results for Wireless Transmission of 3D Brain MRI images: Objective Evaluation of 3D SPIHT and JPEG2K
International audienceIn this paper, we evaluate the robustness of 3D SPIHT and JPEG2K coding algorithm over wireless transmission. For this purpose, an MRI head scan test set of 256 x 256 x 124 voxels has been used. Compressed dataset images are then transmitted over AWGN wireless channel or over Rayleigh wireless channel. Results show the superiority of JPEG2K over these two models. In fact, it has been deduced that JPEG2K is more robust regarding coding errors. Thus we may conclude the necessity of using corrector codes in order to protect the transmitted medical information
Heat treatment effect on p type Zn doped InP substrates
During the process of elaboration of n+ /p InP photodiodes for solar energy conversion, we have observed that the 700 C sulfur diffusion into Zn doped InP substrates strongly modifies the electrical and photoelectrical properties of these substrates. A simple annealing at the same temperature produces nearly equivalent effects. The most relevant modification is a strong, depth independent hole density increase (more than one order of magnitude). A degradation of the photoelectrical parameters : diffusion length L and carrier lifetime τ has also been detected near the surface of the heat treated substrates. The deep traps measured from deep level transient spectroscopy (DLTS) are not typical of the heat treatment.Au cours du processus d'élaboration de photodiodes InP n+ /p pour la conversion d'énergie solaire par diffusion de soufre à 700 C dans des substrats d'InP dopés Zn, les propriétés électriques et photoélectriques des substrats sont fortement modifiées. Les mêmes effets sont observés après un simple recuit des substrats à la même température. La modification la plus notable est une forte augmentation de la densité de trous (plus d'un ordre de grandeur) uniforme en profondeur. Une dégradation superficielle des paramètres photoélectriques, longueur de diffusion L et durée de vie τ des porteurs a aussi été observée. Les pièges profonds détectés dans les substrats après traitement thermique ne sont pas typiques de ce traitement
Treating Addiction: Unraveling the Relationship Between N-acetylcysteine, Glial Glutamate Transport, and Behavior
An in vitro reconstructed human skin equivalent model to study the role of skin integration around percutaneous devices against bacterial infection
Percutaneous devices are a key technology in clinical practice, used to connect internal organs to external medical devices. Examples include prosthesis, catheters and electrical drivelines. Percutaneous devices breach the skin’s natural barrier and create an entry point for pathogens, making device infections a widespread problem. Modification of the percutaneous implant surface to increase skin integration with the aim to reduce subsequent infection is attracting a great deal of attention. While novel surfaces have been tested in various in vitro models used to study skin integration around percutaneous devices, no skin model has been reported, for the study of bacterial infection around percutaneous devices. Here, we report the establishment of an in vitro human skin equivalent model for driveline infections caused by Staphylococcus aureus, the most common cause of driveline-related infections. Three types of mock drivelines manufactured using melt electrowriting (smooth or porous un-seeded and porous pre-seeded with human fibroblasts) were implanted in human skin constructs and challenged with S. aureus. Our results show a high and stable load of S. aureus in association with the skin surface and no signs of S. aureus-induced tissue damage. Furthermore, our results demonstrate that bacterial migration along the driveline surface occurs in micro-gaps caused by insufficient skin integration between the driveline and the surrounding skin consistent with clinical reports from explanted patient drivelines. Thus, the human skin-driveline infection model presented here provides a clinically-relevant and versatile experimental platform for testing novel device surfaces and infection therapeutics.</p
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