150 research outputs found
Fibroma cemento-osificante gingival mandibular: presentación de un caso
Presentamos el caso clínico de una mujer con un fibroma cemento-
osificante gigante dependiente de la encía mandibular
de 20 años de evolución. El fibroma cemento-osificante es un
tumor poco frecuente, clasificado dentro de las lesiones
fibroóseas. Aparece generalmente en hueso y en raras ocasiones
afecta a tejidos gingivales, como ocurre en nuestro caso. Es
una neoplasia de crecimiento lento y bien delimitada, lo que le
confiere un carácter benigno. Con los hallazgos histológicos es
difícil diferenciar el fibroma cemento-osificante de otras lesiones
tales como el osteoblastoma, el osteosarcoma de bajo grado
y particularmente de la displasia fibrosa. Para obtener un
diagnóstico preciso es fundamental guiarnos además por la información
clínica y radiológica y así llevar a cabo un tratamiento
oportuno, que condicione un pronóstico excelente.We report a case of a woman presenting a giant cementoossifying
fibroma depending of the mandibular gingivae. The
evolution of the process was 20 years. Cemento-ossifying
fibroma is a relatively rare tumour classified between fibroosseous
lesions. This lesion appears within the bone although
in some occasions it involves the gingivae soft tissues, as the
case we present. It is a slow-growing and well-defined tumorous
lesion, because of this, it is considered as a benign lesion. The
histologic findings alone may be similar to other pathologies
such as osteoblastoma, low-grade osteosarcoma and particularly
to fibrous dysplasia. An accurate diagnosis requires careful
clinical, radiological and histological correlation in order to
make an optimal treatment and an excellent outcome
UrdA Controls Secondary Metabolite Production and the Balance between Asexual and Sexual Development in Aspergillus Nidulans
The genus Aspergillus includes important plant pathogens, opportunistic human pathogens and mycotoxigenic fungi. In these organisms, secondary metabolism and morphogenesis are subject to a complex genetic regulation. Here we functionally characterized urdA, a gene encoding a putative helix-loop-helix (HLH)-type regulator in the model fungus Aspergillus nidulans. urdA governs asexual and sexual development in strains with a wild-type veA background; absence of urdA resulted in severe morphological alterations, with a significant reduction of conidial production and an increase in cleistothecial formation, even in the presence of light, a repressor of sex. The positive effect of urdA on conidiation is mediated by the central developmental pathway (CDP). However, brlA overexpression was not sufficient to restore wild-type conidiation in the Delta urdA strain. Heterologous complementation of Delta urdA with the putative Aspergillus flavus urdA homolog also failed to rescue conidiation wild-type levels, indicating that both genes perform different functions, probably reflected by key sequence divergence. UrdA also represses sterigmatocystin (ST) toxin production in the presence of light by affecting the expression of aflR, the activator of the ST gene cluster. Furthermore, UrdA regulates the production of several unknown secondary metabolites, revealing a broader regulatory scope. Interestingly, UrdA affects the abundance and distribution of the VeA protein in hyphae, and our genetics studies indicated that veA appears epistatic to urdA regarding ST production. However, the distinct fluffy phenotype of the Delta urdA Delta veA double mutant suggests that both regulators conduct independent developmental roles. Overall, these results suggest that UrdA plays a pivotal role in the coordination of development and secondary metabolism in A. nidulans.This research and The APC was supported by the Department of Biological Sciences at Northern Illinois University. The research at CIB-CSIC was funded by MINECO/FEDER/EU (grant BFU2015-66806-R). The research at UPV/EHU was funded by grant EHUA15/08
Influence of primary particle density in the morphology of agglomerates
Agglomeration processes occur in many different realms of science such as
colloid and aerosol formation or formation of bacterial colonies. We study the
influence of primary particle density in agglomerate structure using
diffusion-controlled Monte Carlo simulations with realistic space scales
through different regimes (DLA and DLCA). The equivalence of Monte Carlo time
steps to real time scales is given by Hirsch's hydrodynamical theory of
Brownian motion. Agglomerate behavior at different time stages of the
simulations suggests that three indices (fractal exponent, coordination number
and eccentricity index) characterize agglomerate geometry. Using these indices,
we have found that the initial density of primary particles greatly influences
the final structure of the agglomerate as observed in recent experimental
works.Comment: 11 pages, 13 figures, PRE, to appea
Homeobox transcription factor HbxA influences expression of over one thousand genes in the model fungus \u3ci\u3eAspergillus nidulans\u3c/i\u3e
In fungi, conserved homeobox-domain proteins are transcriptional regulators governing development. In Aspergillus species, several homeobox-domain transcription factor genes have been identified, among them, hbxA/hbx1. For instance, in the opportunistic human pathogen Aspergillus fumigatus, hbxA is involved in conidial production and germination, as well as virulence and secondary metabolism, including production of fumigaclavines, fumiquinazolines, and chaetominine. In the agriculturally important fungus Aspergillus flavus, disruption of hbx1 results in fluffy aconidial colonies unable to produce sclerotia. hbx1 also regulates production of aflatoxins, cyclopiazonic acid and aflatrem. Furthermore, transcriptome studies revealed that hbx1 has a broad effect on the A. flavus genome, including numerous genes involved in secondary metabolism. These studies underline the importance of the HbxA/Hbx1 regulator, not only in developmental processes but also in the biosynthesis of a broad number of fungal natural products, including potential medical drugs and mycotoxins. To gain further insight into the regulatory scope of HbxA in Aspergilli, we studied its role in the model fungus Aspergillus nidulans. Our present study of the A. nidulans hbxA-dependent transcriptome revealed that more than one thousand genes are differentially expressed when this regulator was not transcribed at wild-type levels, among them numerous transcription factors, including those involved in development as well as in secondary metabolism regulation. Furthermore, our metabolomics analyses revealed that production of several secondary metabolites, some of them associated with A. nidulans hbxA-dependent gene clusters, was also altered in deletion and overexpression hbxA strains compared to the wild type, including synthesis of nidulanins A, B and D, versicolorin A, sterigmatocystin, austinol, dehydroaustinol, and three unknown novel compounds
Homeobox transcription factor HbxA influences expression of over one thousand genes in the model fungus \u3ci\u3eAspergillus nidulans\u3c/i\u3e
In fungi, conserved homeobox-domain proteins are transcriptional regulators governing development. In Aspergillus species, several homeobox-domain transcription factor genes have been identified, among them, hbxA/hbx1. For instance, in the opportunistic human pathogen Aspergillus fumigatus, hbxA is involved in conidial production and germination, as well as virulence and secondary metabolism, including production of fumigaclavines, fumiquinazolines, and chaetominine. In the agriculturally important fungus Aspergillus flavus, disruption of hbx1 results in fluffy aconidial colonies unable to produce sclerotia. hbx1 also regulates production of aflatoxins, cyclopiazonic acid and aflatrem. Furthermore, transcriptome studies revealed that hbx1 has a broad effect on the A. flavus genome, including numerous genes involved in secondary metabolism. These studies underline the importance of the HbxA/Hbx1 regulator, not only in developmental processes but also in the biosynthesis of a broad number of fungal natural products, including potential medical drugs and mycotoxins. To gain further insight into the regulatory scope of HbxA in Aspergilli, we studied its role in the model fungus Aspergillus nidulans. Our present study of the A. nidulans hbxA-dependent transcriptome revealed that more than one thousand genes are differentially expressed when this regulator was not transcribed at wild-type levels, among them numerous transcription factors, including those involved in development as well as in secondary metabolism regulation. Furthermore, our metabolomics analyses revealed that production of several secondary metabolites, some of them associated with A. nidulans hbxA-dependent gene clusters, was also altered in deletion and overexpression hbxA strains compared to the wild type, including synthesis of nidulanins A, B and D, versicolorin A, sterigmatocystin, austinol, dehydroaustinol, and three unknown novel compounds
Characterization of surface layers in Zn-diffused LiNbO3 waveguides by heavy ion elastic recoil detection
Copyright (2002) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 81.11 (2002): 1981-1983 and may be found at http://apl.aip.org
The pH-responsive PacC transcription factor of Aspergillus fumigatus governs epithelial entry and tissue invasion during pulmonary aspergillosis
Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. Raw data have been deposited in the Gene Expression Omnibus (GEO) (http://www.ncbi.nlm.nih.gov/geo/) under accession number GSE54810. Funding: This work was supported in part by grants to EMB from the MRC (G0501164) and BBSRC (BB/G009619/1), to EMB and NDR from the Wellcome Trust (WT093596MA), to MB from Imperial College London (Division of Investigative Sciences PhD Studentship), to HH from the ERA-NET PathoGenoMics project TRANSPAT, Austrian Science Foundation (FWF I282-B09), to SGF from the National Institutes of Health, USA (R01AI073829). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Size-induced superantiferromagnetism with reentrant spin-glass behavior in metallic nanoparticles of TbCu2
An unusual 4f -superantiferromagnetic state characterized by simultaneous antiferromagnetic and spin-glass behaviors induced by particle-size reduction is revealed in metallic nanoparticles (≈ 9 nm) of TbCu 2 . The Néel temperature is 46 K and the glassy freezing is below ≈ 9 K and governed by a critical slowing down process. Neutron diffraction at 1.8 K establishes the superantiferromagnetism. The latter is settled by the nanoparticle moments and the freezing mechanism is provided by the surface spins
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