1,932 research outputs found

    Isolation, characterisation and expression patterns of a RAD51 ortholog from Pleurotus ostreatus

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    AB: Using degenerated primers for conserved regions of RecA homologs we have isolated a gene from Pleurotus ostreatus that shows characteristic features of RAD51 homologs. The encoded amino acid sequence of P. ostreatus RAD51 (PoRAD51) shows greatest sequence similarities with RAD51 from Coprinus cinereus (89% identity). Furthermore the genomic organisation of PoRAD51 is almost identical to that of RAD51 from C. cinereus. Northern analysis shows that the expression of PoRAD51 is found in vegetative mycelium, and fruit body tissue, and that it is expressed at elevated levels in lamellae/basidia and following DNA damage. A sporulation deficient mutant strain of P. ostreatus (ATTC 58937) showed expression patterns of the RAD51 gene that are similar those of the normal sporulating strain

    Tres nuevas especies de killis (Cyprinodontiformes: Nothobranchiidae) de Guinea Ecuatorial

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    Two new Mesoaphyosemion species and one new species of the ’Aphyosemion’ herzogi group are described from the inland of Equatorial Guinea. The results of mtDNA analyses of most of the known phenotypes of the genus Mesoaphyosemion and the ‘Aphyosemion’ herzogi species group, respectively, are presented. Both new Mesoaphyosemion species have dark blotches on the posterior flanks and resemble M. maculatum from Gabon, yet they are not closely related to that species. Although the two new species occur in very close proximity, DNA results suggest no close relationship. The ‘Aphyosemion’ herzogi species group has a similar distribution as the genus Mesoaphyosemion, but with its northern boundary in southern Cameroon. Based on mtDNA the new ‘Aphyosemion’ from the Mitemele drainage in south west Equatorial Guinea is basal species to the remaining species group. It is distinguished from the two described congeners, ‘A.’ bochtleri and ‘A.’ herzogi by a diagnostic combination of colouration characters. Unpaired fins and flanks have a green background and caudal peduncle is often yellow to golden with dark red irregular dark red bars. The genetic dataindicate that the species group contains several additional, genetically and by colour pattern well separated, potentiallyundescribedspecies. urn:lsid:zoobank.org:pub:2752DAEA-BEFE-4D6D-8D5C-FB3F0D265A4DSe describen para la parte continental de Guinea Ecuatorial dos nuevas especies de Mesoaphyosemion y una nueva especie del grupo de especies ‘Aphyosemion’ herzogi. También, se presentan los resultados de los análisis de DNAmt de casi todos los fenotipos conocidos del género Mesoaphyosemion y del grupo de especies ‘Aphyosemion’ herzogi. Ambas nuevas especies de Mesoaphyosemion tienen manchas oscuras en los flancos posteriores y se parecen a M. maculatum de Gabón, pero no están estrechamente relacionadas con esa especie. Aunque las dos nuevas especies son próximas, los resultados del ADN sugieren que no existe entre ellas una relación cercana. El grupo de especies ‘Aphyosemion’ herzogi tiene una distribución similar a la de Mesoaphyosemion, pero con su límite norte en el sur de Camerún. Basado en ADNmt, el nuevo ‘Aphyosemion’ de la cuenca del río Mitemele, en el suroeste de la parte continental de Guinea Ecuatorial, es una especie basal al resto de las especies estudiadas. Se distingue de los dos congéneres descritos, ‘A.’ bochtleri y ‘A.’ herzogi por una combinación de caracteres diagnósticos de la coloración. Las aletas impares y los flancostienen un fondo verde y el pedúnculo caudal suele ser de color amarillo a dorado con barras rojo oscuro irregulares. Los datos genéticosindicanque el grupo de especies contiene varias especies más, que están genéticamente y por patrón de coloración bien delimitadas, y que no han sido formalmente descritas

    Reduced Susceptibility to Two-Stage Skin Carcinogenesis in Mice with Epidermis-Specific Deletion of Cd151

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    Altered expression of the tetraspanin CD151 is associated with skin tumorigenesis; however, whether CD151 is causally involved in the tumorigenic process is not known. To evaluate its role in tumor formation, we subjected epidermis-specific Cd151 knockout mice to chemical skin carcinogenesis. Mice lacking epidermal Cd151 developed fewer and smaller tumors than wild-type mice after treatment with 7,12-dimethylbenzanthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, Cd151-null epidermis showed a reduced hyperproliferative response to short-term treatment with TPA as compared with wild-type skin, whereas epidermal turnover was increased. Tumors were formed in equal numbers after DMBA-only treatment. We suggest that DMBA-initiated keratinocytes lacking Cd151 leave their niches in the epidermis and hair follicles in response to TPA treatment and subsequently are lost by differentiation. Because genetic ablation of Itga3 also reduced skin tumor formation, we tested whether reduced expression of α3 could further suppress tumor formation in epidermis-specific Cd151 knockout mice. Although DMBA/TPA-induced formation of skin tumors was similar in compound heterozygotes for Cd151 and Itga3 to that in wild-type mice, heterozygosity for Itga3 on a Cd151-null background diminished tumorigenesis, suggesting genetic interaction between the two genes. We thus identify CD151 as a critical factor in TPA-dependent skin carcinogenesis

    Mechanistic insight in the selective delignification of wheat straw by three white-rot fungal species through quantitative 13C-IS py-GC–MS and whole cell wall HSQC NMR

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    Background The white-rot fungi Ceriporiopsis subvermispora (Cs), Pleurotus eryngii (Pe), and Lentinula edodes (Le) have been shown to be high-potential species for selective delignification of plant biomass. This delignification improves polysaccharide degradability, which currently limits the efficient lignocellulose conversion into biochemicals, biofuels, and animal feed. Since selectivity and time efficiency of fungal delignification still need optimization, detailed understanding of the underlying mechanisms at molecular level is required. The recently developed methodologies for lignin quantification and characterization now allow for the in-depth mapping of fungal modification and degradation of lignin and, thereby, enable resolving underlying mechanisms. Results Wheat straw treated by two strains of Cs (Cs1 and Cs12), Pe (Pe3 and Pe6) and Le (Le8 and Le10) was characterized using semi-quantitative py-GC–MS during fungal growth (1, 3, and 7 weeks). The remaining lignin after 7 weeks was quantified and characterized using ¹³C lignin internal standard based py-GC–MS and whole cell wall HSQC NMR. Strains of the same species showed similar patterns of lignin removal and degradation. Cs and Le outperformed Pe in terms of extent and selectivity of delignification (Cs ≥ Le >> Pe). The highest lignin removal [66% (w/w); Cs1] was obtained after 7 weeks, without extensive carbohydrate degradation (factor 3 increased carbohydrate-to-lignin ratio). Furthermore, though after treatment with Cs and Le comparable amounts of lignin remained, the structure of the residual lignin vastly differed. For example, Cα-oxidized substructures accumulated in Cs treated lignin up to 24% of the total aromatic lignin, a factor two higher than in Le-treated lignin. Contrarily, ferulic acid substructures were preferentially targeted by Le (and Pe). Interestingly, Pe-spent lignin was specifically depleted of tricin (40% reduction). The overall subunit composition (H:G:S) was not affected by fungal treatment. Conclusions Cs and Le are both able to effectively and selectively delignify wheat straw, though the underlying mechanisms are fundamentally different. We are the first to identify that Cs degrades the major β-O-4 ether linkage in grass lignin mainly via Cβ–O–aryl cleavage, while Cα–Cβ cleavage of inter-unit linkages predominated for Le. Our research provides a new insight on how fungi degrade lignin, which contributes to further optimizing the biological upgrading of lignocellulose. Electronic supplementary material The online version of this article (10.1186/s13068-018-1259-9) contains supplementary material, which is available to authorized users

    Development of a Framework Structuring Themes in the Course of Adverse Drug Reactions from a Patient's Perspective

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    INTRODUCTION: There is a need for more extensive information about adverse drug reactions (ADRs) for patients than currently available, including information on the course of ADRs. Aspects characterising the course of ADRs from the patient perspective have not been identified before.OBJECTIVE: We aimed to develop a framework based on common themes in the course of ADRs identified from patient descriptions in patient-reported ADRs.METHODS: In this qualitative study, patient descriptions of the course of patient-reported ADRs were analysed by a thematic analysis with an inductive approach using three different existing datasets containing patient-reported ADRs. Two datasets included patient-reported ADRs from cohort event monitoring of biologics and direct oral anticoagulants and one dataset included spontaneous reports from patients concerning medication for lower urinary tract symptoms. A conceptual framework was developed from the identified main themes and subthemes.RESULTS: Patient-reported data concerning 3888 ADRs were analysed. Six main themes with multiple subthemes were identified from patient descriptions of the course of ADRs. Four themes were descriptive: frequency of an ADR episode, duration of an ADR episode, moment or period of ADR occurrence, and development in the intensity of the ADR. Two themes concerned factors influencing the course of ADRs: triggering factors and improving factors.CONCLUSIONS: The presented framework illustrates that patients describe extensive details on the course and timeframe of ADRs. The identified themes provide a basis for improving the systematic data collection of more extensive details about ADRs from patients as a first step towards the provision of more comprehensive ADR information to patients.</p

    Pharmacological inhibition of c-Abl compromises genetic stability and DNA repair in Bcr-Abl-negative cells

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    Imatinib inhibits the kinase activity of Bcr-Abl and is currently the most effective drug for treatment of chronic myeloid leukemia (CML). Imatinib also blocks c-Abl, a physiological tyrosine kinase activated by a variety of stress signals including damaged DNA. We investigated the effect of pharmacological inhibition of c-Abl on the processing of irradiation-induced DNA damage in Bcr-Abl-negative cells. Cell lines and peripheral blood mononuclear cells (PBMCs) from healthy volunteers were treated with imatinib or dasatinib before gamma-irradiation. Inhibition of c-Abl caused an enhanced irradiation-induced mutation frequency and slowdown of DNA repair, whereas imatinib was ineffective in cells expressing a T315I variant of c-Abl. Mutation frequency and repair kinetics were also studied in c-Abl-/- murine embryonic fibroblasts (MEFs) retransfected with wild-type c-Abl (wt-Abl) or a kinase-defect variant of Abl (KD-Abl). Enhanced mutation frequency as well as delayed DNA repair was observed in cells expressing KD-Abl. These data indicate that pharmacological inhibition of c-Abl compromises DNA-damage response

    Dasatinib reverses Cancer-associated Fibroblasts (CAFs) from primary Lung Carcinomas to a Phenotype comparable to that of normal Fibroblasts

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    Cancer associated fibroblasts (CAFs) play a critical role for growth, invasion, and metastasis of cancer. Therefore, targeting CAFs with small molecule inhibitors may be an attractive anti-tumor strategy. The current study aims to identify small molecule kinase inhibitors affecting CAF's growth and to characterize the biological effects of active compounds on primary CAFs from lung cancer. We screened two individual CAF strains for their sensitivity to a panel of 160 kinase inhibitors. Five kinase inhibitors were identified inhibiting more than 50% of the growth of both cell lines. Three of them were inhibitors of PDGFR at nanomolar concentrations. Therefore, we further tested the FDA approved PDGFR inhibitors Dasatinib, Nilotinib, Sorafenib, and Imatinib. All 37 CAF strains investigated were highly sensitive to Dasatinib at clinically relevant concentrations. Imatinib was slightly less effective, whereas the inhibitory effects of Nilotinib and Sorafenib were significantly less pronounced
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