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Scheckenbach K.E.L.,University of Geneva | Crespin S.,University of Geneva | Kwak B.R.,University of Geneva | Chanson M.,University of Geneva | Chanson M.,Geneva Lab
Journal of Vascular Research | Year: 2011

Inflammation is a highly regulated process with common but also specific characteristics in each tissue affected. Recruitment of leukocytes from the blood to the injured tissue is an important early step in the inflammatory cascade. This review highlights the role of connexins (Cxs) in the regulation of both acute and chronic inflammatory processes. Cxs form gap junction channels that provide a cytoplasmic continuity between adjacent cells allowing the intercellular exchange of ions and metabolites. Their structural halves form connexons or hemichannels. Each of them consists of 6 Cx proteins and hemichannels not taking part in gap junction formation but facilitating the release of small molecules such as ATP. Based on the differential distribution of various Cxs in different tissues such as the brain, lung capillaries and large blood vessels, our aim was to analyze the specific roles of Cxs in the inflammatory process in these tissues. Three typical sites of inflammation were chosen to shed light on similarities and differences in several types of responses: (1) atherosclerosis as a model for chronic inflammation, (2) the lung as an example of acute inflammation and (3) the 'immune-privileged' environment of the brain to highlight specific reactions of the vasculature to ischemic damage and inflammation at this site. © 2010 S. Karger AG, Basel. Source

Mou C.,Roslin Institute | Pitel F.,French National Institute for Agricultural Research | Gourichon D.,French National Institute for Agricultural Research | Vignoles F.,French National Institute for Agricultural Research | And 8 more authors.
PLoS Biology | Year: 2011

Vertebrate skin is characterized by its patterned array of appendages, whether feathers, hairs, or scales. In avian skin the distribution of feathers occurs on two distinct spatial levels. Grouping of feathers within discrete tracts, with bare skin lying between the tracts, is termed the macropattern, while the smaller scale periodic spacing between individual feathers is referred to as the micropattern. The degree of integration between the patterning mechanisms that operate on these two scales during development and the mechanisms underlying the remarkable evolvability of skin macropatterns are unknown. A striking example of macropattern variation is the convergent loss of neck feathering in multiple species, a trait associated with heat tolerance in both wild and domestic birds. In chicken, a mutation called Naked neck is characterized by a reduction of body feathering and completely bare neck. Here we perform genetic fine mapping of the causative region and identify a large insertion associated with the Naked neck trait. A strong candidate gene in the critical interval, BMP12/GDF7, displays markedly elevated expression in Naked neck embryonic skin due to a cis-regulatory effect of the causative mutation. BMP family members inhibit embryonic feather formation by acting in a reaction-diffusion mechanism, and we find that selective production of retinoic acid by neck skin potentiates BMP signaling, making neck skin more sensitive than body skin to suppression of feather development. This selective production of retinoic acid by neck skin constitutes a cryptic pattern as its effects on feathering are not revealed until gross BMP levels are altered. This developmental modularity of neck and body skin allows simple quantitative changes in BMP levels to produce a sparsely feathered or bare neck while maintaining robust feather patterning on the body. © 2011 Mou et al. Source

Oliva E.,Harvard University | Egger J.-F.,Geneva Lab | Young R.H.,Harvard University
American Journal of Surgical Pathology | Year: 2014

Twenty-seven endometrioid stromal sarcomas of the ovary from patients 38 to 76 (mean 56) years of age are reported. The tumors were unilateral in 20 cases and bilateral in 7. They were solid (9), solid and cystic (9), or predominantly cystic (6) when this information was known and ranged from 1 to 20 (mean 9.5) cm. The solid areas typically had a tan-yellow cut surface, with areas of hemorrhage and/or necrosis noted in 6; however, in addition, blood was often present in the cyst lumens. On microscopic examination, the predominant and frequently exclusive pattern was a diffuse growth of small cells with interspersed arterioles, the latter appearing round to elongated. A fibromatous pattern was present in 14 of the tumors but was extensive in only 3. A vague nodular growth was observed in 10 tumors but was never striking; a storiform growth was seen in 2 tumors, being conspicuous in 1. Hyaline plaques were present in 10 tumors but were striking in only 2. Sex cord-like or smooth muscle differentiation was seen in 7 and 6 tumors, respectively, being striking in 2 and 3 of them. Foam cells were present in 6 tumors. The tumors showed minimal cytologic atypia. The mitotic index ranged from <1 to 17/10 high-power fields (HPF), being <1/10 HPF in 12, 1 to 5/10 HPF in 9, 6 to 10/10 HPF in 2, and >10/10 HPF in 4 tumors. Infarct-type necrosis was noted in 12 tumors. Hemorrhage, typically recent, was seen in 20 cases, being conspicuous in 5. Ovarian endometriosis was intimately associated with the tumor in 16 cases. Seven patients had stage I tumors, 5 stage II, 13 stage III, and 2 stage IV. Follow-up information was available for 21 patients; 10 were alive and free of disease from 4 to 21 years postoperatively (follow-up being ≥11 y in 5); 6 were alive with disease from 1 to 22 years postoperatively; 5 patients are known to have died of disease, with the interval being unknown in 1, and 2, 4, 13, and 17 years in the others. Follow-up information was unavailable in the remaining 6 patients. These findings indicate that these tumors, as in the uterus, often have an indolent course with a better prognosis than other ovarian sarcomas, indicating the importance of correct diagnosis. The differential diagnosis of these neoplasms is in the first instance with a metastasis from the uterus; knowledge of the status of the uterus is paramount in this distinction. Associated ovarian endometriosis suggests a primary tumor. When a primary ovarian origin is determined, the differential diagnosis is most often with a sex cord-stromal tumor, particularly a granulosa cell tumor because of a diffuse growth of cells with scant cytoplasm. Copyright © 2014 by Lippincott Williams & Wilkins. Source

Helaers R.,University of Namur | Milinkovitch M.C.,Geneva Lab
BMC Bioinformatics | Year: 2010

Background: The development, in the last decade, of stochastic heuristics implemented in robust application softwares has made large phylogeny inference a key step in most comparative studies involving molecular sequences. Still, the choice of a phylogeny inference software is often dictated by a combination of parameters not related to the raw performance of the implemented algorithm(s) but rather by practical issues such as ergonomics and/or the availability of specific functionalities.Results: Here, we present MetaPIGA v2.0, a robust implementation of several stochastic heuristics for large phylogeny inference (under maximum likelihood), including a Simulated Annealing algorithm, a classical Genetic Algorithm, and the Metapopulation Genetic Algorithm (metaGA) together with complex substitution models, discrete Gamma rate heterogeneity, and the possibility to partition data. MetaPIGA v2.0 also implements the Likelihood Ratio Test, the Akaike Information Criterion, and the Bayesian Information Criterion for automated selection of substitution models that best fit the data. Heuristics and substitution models are highly customizable through manual batch files and command line processing. However, MetaPIGA v2.0 also offers an extensive graphical user interface for parameters setting, generating and running batch files, following run progress, and manipulating result trees. MetaPIGA v2.0 uses standard formats for data sets and trees, is platform independent, runs in 32 and 64-bits systems, and takes advantage of multiprocessor and multicore computers.Conclusions: The metaGA resolves the major problem inherent to classical Genetic Algorithms by maintaining high inter-population variation even under strong intra-population selection. Implementation of the metaGA together with additional stochastic heuristics into a single software will allow rigorous optimization of each heuristic as well as a meaningful comparison of performances among these algorithms. MetaPIGA v2.0 gives access both to high customization for the phylogeneticist, as well as to an ergonomic interface and functionalities assisting the non-specialist for sound inference of large phylogenetic trees using nucleotide sequences. MetaPIGA v2.0 and its extensive user-manual are freely available to academics at http://www.metapiga.org. © 2010 Helaers and Milinkovitch; licensee BioMed Central Ltd. Source

Lalive P.H.,University of Geneva | Neuhaus O.,Kliniken Landkreis Sigmaringen | Benkhoucha M.,University of Geneva | Burger D.,Geneva Lab | And 3 more authors.
CNS Drugs | Year: 2011

Glatiramer acetate is a synthetic, random copolymer widely used as a first-line agent for the treatment of relapsing-remitting multiple sclerosis (MS). While earlier studies primarily attributed its clinical effect to a shift in the cytokine secretion of CD4 T helper (Th) cells, growing evidence in MS and its animal model, experimental autoimmune encephalomyelitis (EAE), suggests that glatiramer acetate treatment is associated with a broader immunomodulatory effect on cells of both the innate and adaptive immune system. To date, glatiramer acetate-mediated modulation of antigen-presenting cells (APC) such as monocytes and dendritic cells, CD4 Th cells, CD8 T cells, Foxp3 regulatory T cells and antibody production by plasma cells have been reported; in addition, most recent investigations indicate that glatiramer acetate treatment may also promote regulatory B-cell properties. Experimental evidence suggests that, among these diverse effects, a fostering interplay between anti-inflammatory T-cell populations and regulatory type II APC may be the central axis in glatiramer acetate-mediated immune modulation of CNS autoimmune disease. Besides altering inflammatory processes, glatiramer acetate could exert direct neuroprotective andor neuroregenerative properties, which could be of relevance for the treatment of MS, but even more so for primarily neurodegenerative disorders, such as Alzheimers or Parkinsons disease. In this review, we provide a comprehensive and critical overview of established and recent findings aiming to elucidate the complex mechanism of action of glatiramer acetate. © 2011 Adis Data Information BV. All rights reserved. Source

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