Infectious Diseases

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Pulmonary infections are caused by a wide range of pathogenic microorganisms, including bacteria, viruses, fungi, and parasites. The most common lung infections in immunocompetent hosts are caused by pyogenic bacteria (e.g., Streptococcus pneumoniae), common respiratory viruses, and mycoplasma. These infections are usually diagnosed by clinical and microbiologic studies, including cultures and serology tests. Lung biopsy is rarely used in these diagnoses. Patients with life-threatening pneumonia, especially those who are immunocompromised, are more likely to undergo lung biopsy to rule out unusual infections not easily diagnosed using conventional microbiologic methods and for which treatment strategies may be different. Pathogens more likely to be diagnosed using lung biopsy for which there are characteristic pathologic changes are highlighted in this chapter and listed in Table 4.1

Lung adenocarcinoma: Sustained subtyping with immunohistochemistry and EGFR, HER2 and KRAS mutational status

Pulmonary adenocarcinomas are still in the process of achieving morphological, immunohistochemical and genetic standardization. The ATS/ERS/IASLC proposed classification for lung adenocarcinomas supports the value of the identification of histological patterns, specifically in biopsies. Thirty pulmonary adenocarcinomas were subjected to immunohistochemical study (CK7, CK5, 6, 18, CK20, TTF1, CD56, HER2, EGFR and Ki-67), FISH and PCR followed by sequencing and fragment analysis for EGFR, HER2 and KRAS. Solid pattern showed lower TTF1 and higher Ki-67 expression. TTF1 expression was higher in non-mucinous lepidic and micropapillary patterns when compared to acinar and solid and acinar, solid and mucinous respectively. Higher Ki67 expression was present in lepidic and solid patterns compared to mucinous. EGFR membranous staining had increasing expression from non-mucinous lepidic/BA pattern to solid pattern and micropapillary until acinar pattern. EGFR mutations, mainly in exon 19, were more frequent in females, together with non-smoking status, while KRAS exon 2 mutations were statistically more frequent in males, especially in solid pattern. FISH EGFR copy was correlated gross, with mutations. HER2 copy number was raised in female tumours without mutations, in all cases. Although EGFR and KRAS mutations are generally considered mutually exclusive, in rare cases they can coexist as it happened in one of this series, and was represented in acinar pattern with rates of 42.9% and 17.9%, respectively. EGFR mutations were more frequent in lepidic/BA and acinar patterns. Some cases showed different EGFR mutations. The differences identified between the adenocarcinoma patterns reinforce the need to carefully identify the patterns present, with implications in diagnosis and in pathogenic understanding. EGFR and KRAS mutational status can be determined in biopsies representing bronchial pulmonary carcinomas because when a mutation is present it is generally present in all the histological patterns.info:eu-repo/semantics/publishedVersio

Enhanced formation of giant cells in common variable immunodeficiency: Relation to granulomatous disease.

Peripheral monocytes from patients with common variable immunodeficiency (CVID) had on average a 2 fold greater tendency to form giant cells in medium without additional cytokines. Giant cell formation was faster and 3 to 5 fold higher in most CVID cells compared to normal. Addition of IL4, GMCSF, IFNγ, TNFa and both T cell and monocyte conditioned media promoted monocyte fusion of some CVID individuals over 5 fold the normal average level, with combinations of cytokines and monokines acting synergistically. The reduction of normal giant cell formation by anti-IFNγ antibody and a greater tendency of CVID cells to fuse in immunoglobulin conditioned media suggests that standard IVIg treatment contributes to granuloma formation. CVID and normal giant cells expressed similar levels of phenotypic molecules and had similar phagocytic activity. Monocytes from many CVID patients have an elevated tendency to fuse which may explain the high incidence of granulomatous complications in CVID

TLR9 activation is a key event for the maintenance of a mycobacterial antigen-elicited pulmonary granulomatous response

Type 1 (Th1) granulomas can be studied in mice sensitized with mycobacterium antigens followed by challenge of agarose beads covalently coupled to purified protein derivative. TLR9 is known to play a role in the regulation of Th1 responses; thus, we investigated the role of TLR9 in granuloma formation during challenge with mycobacterium antigens and demonstrated that mice deficient in TLR9 had increased granuloma formation, but a dramatically altered cytokine phenotype. Th1 cytokine levels of IFN-γ and IL-12 in the lungs were decreased in TLR9 –/– mice when compared to wild-type mice. In contrast, Th2 cytokine levels of IL-4, IL-5, and IL-13 were increased in TLR9 –/– mice. The migration of CD4 + T cells in the granuloma was impaired, while the number of F4/80 + macrophages was increased in TLR9 –/– mice. Macrophages in the lungs of the TLR9-deficient animals with developing granulomas expressed significantly lower levels of the classically activated macrophage marker, nitric oxide synthase, but higher levels of the alternatively activated macrophage markers such as ‘found in inflammatory zone-1′ antigen and Arginase-1. These results suggest that TLR9 plays an important role in maintaining the appropriate phenotype in a Th1 granulomatous response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57331/1/2847_ftp.pd

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Les convertisseurs à base de Si atteignent leurs limites. Face à ces besoins, le GaN, avec sa vitesse de saturation des électrons et le champ électrique de claquage élevés est candidat idéal pour réaliser des redresseurs, surtout s’il est épitaxié sur substrat à bas cout. Ce travail est dédié au développement des diodes Schottky sur AlGaN/GaN. Une couche de SiNx en faible traction a été obtenue. Un contact ohmique de Ti/Al avec une gravure partiel a donné une Rc de 2.8 Ω.mm avec une résistance Rsh de 480 Ω/□. Des diodes Schottky avec les étapes issues de ces études ont été fabriqué. La diode recuite à 400 °C avec 30 nm de profondeur de gravure a montré une hauteur de barrière de 0,82 eV et un facteur d'idéalité de 1,49. La diode a présenté une très faible densité de courant de fuite de 8.45x10-8 A.mm-1 à -400 V avec une tension de claquage entre 480 V et 750 V.Si-based devices for power conversion applications are reaching their limits. Wide band gap GaN is particularly interesting due to the high electron saturation velocity and high breakdown electric field, especially when epitaxied on low cost substrates such as Si. This work was dedicated to the development and fabrication of the Schottky diode on AlGaN/GaN on Si. SiNx passivation in very low tensile strain is used. Ti (70 nm)/Al (180 nm) partially recessed ohmic contacts annealed at 800 ºC exhibited a 2.8 Ω.mm Rc with a sheet resistance of 480 Ω/sq. Schottky diodes with the previously cited passivation and ohmic contact were fabricated with a fully recessed Schottky contact annealed at 400 ºC. A Schottky barrier height of 0.82 eV and an ideality factor of 1.49 were obtained. These diodes also exhibited a very low leakage current density (up to -400 V) of 8.45x10-8 A.mm-1. The breakdown voltage varied between 480 V and 750 V

Interactions coopératives 3D distantes en environnements virtuels : gestion des problèmes réseaux

Dans cette thèse nous nous intéressons spécialement à l'étude des conséquences d'un problème réseau sur le comportement d'un environnement virtuel distribué. En effet, le réseau est un facteur qui agit directement sur la performance des systèmes d'environnements virtuels distribués : les problèmes de communication comme la latence réseau ou la déconnexion d'un site affectent directement les interactions distantes au sein d'un environnement virtuel. Nous proposons donc des solutions qui ont pour but d'atténuer l'effet de ces problèmes. Nos solutions se divisent en deux catégories : des solutions techniques au niveau du noyau d'un système d'environnements virtuels et des solutions au niveau applicatif. Au niveau noyau nous avons conçu un algorithme de synchronisation tolérant au délai et à la perte d'un site suite à une déconnexion. Nous avons réalisé aussi un mécanisme qui permet la migration d'objets d'un site à un autre au cours d'une simulation. Ce mécanisme a permis par la suite l'ajout et la suppression dynamique d'un site au cours d'une simulation.Au niveau applicatif nous avons réalisé un système d'informations qui a pour but de détecter un délai ou une déconnexion et de donner à l'utilisateur la conscience de l'existence d'un problème réseau à l'aide de métaphores visuelles. Ces métaphores doivent attirer l'attention d'un utilisateur sur le fait que quelques uns des objets virtuels ne sont pas disponibles ou pas à jour suite à une déconnexion par exemple.RENNES-INSA (352382210) / SudocBREST-ENIB (290192307) / SudocSudocFranceF