194 research outputs found
Differential chlamydospore development by the analyzed <i>Candida</i> strains in Staib liquid medium.
No full text<p><i>C. dubliniensis</i> wild type Wü284 and the <i>C. albicans nrg1</i>Δ mutant MMC3 form chlamydospores, in contrast to the <i>C. albicans</i> wild type SC5314. The fungal strains were grown for 28 h in Staib medium at 25°C and inspected by microscopy (scale bar: 10 µm).</p
Global Transcriptome Sequencing Identifies Chlamydospore Specific Markers in Candida albicans and Candida dubliniensis
No full textCandida albicans and Candida dubliniensis are pathogenic fungi that are highly related but differ in virulence and in some phenotypic traits. During in vitro growth on certain nutrient-poor media, C. albicans and C. dubliniensis are the only yeast species which are able to produce chlamydospores, large thick-walled cells of unknown function. Interestingly, only C. dubliniensis forms pseudohyphae with abundant chlamydospores when grown on Staib medium, while C. albicans grows exclusively as a budding yeast. In order to further our understanding of chlamydospore development and assembly, we compared the global transcriptional profile of both species during growth in liquid Staib medium by RNA sequencing. We also included a C. albicans mutant in our study which lacks the morphogenetic transcriptional repressor Nrg1. This strain, which is characterized by its constitutive pseudohyphal growth, specifically produces masses of chlamydospores in Staib medium, similar to C. dubliniensis. This comparative approach identified a set of putatively chlamydospore-related genes. Two of the homologous C. albicans and C. dubliniensis genes (CSP1 and CSP2) which were most strongly upregulated during chlamydospore development were analysed in more detail. By use of the green fluorescent protein as a reporter, the encoded putative cell wall related proteins were found to exclusively localize to C. albicans and C. dubliniensis chlamydospores. Our findings uncover the first chlamydospore specific markers in Candida species and provide novel insights in the complex morphogenetic development of these important fungal pathogens
Proteins encoded by <i>cdCSP1</i> and <i>cdCSP2</i> are specifically expressed and located in chlamydospores.
No full text<p><i>C. dubliniensis</i> wild type Wü284 (A) and the <i>C. dubliniensis</i> GFP reporter strains Cd30750G1A/B (cdCsp1-GFP) (B) and Cd40770G1A/B (cdCsp2-GFP) (C) were grown in YPD and Staib liquid medium for 28 h at 25°C, and on rice-extract agar for 3 d at 25°C, respectively, and inspected by phase contrast and fluorescence microscopy. Fluorescence microscopy demonstrated that the genes of interest are specifically induced during growth in Staib medium and that the encoded proteins exclusively localize to chlamydospores. The two independently constructed A/B-GFP reporter strains behaved identically and only one of them is shown (scale bar: 10 µm).</p
Identification of chlamydospore specific genes in <i>Candida</i>.
No full text<p>Venn diagram of genes which were ≥ two fold up- (A) and downregulated (B) in both the <i>C. albicans nrg1</i>Δ mutant and the <i>C. dubliniensis</i> wild type during growth in Staib medium.</p
Induced expression levels of genes <i>CSP1</i> and <i>CSP2</i> during chlamydospore formation.
No full text<p><i>C. dubliniensis</i> Wü284, <i>C. albicans</i> SC5314 and the <i>C. albicans nrg1</i>Δ mutant were grown for 28 h in Staib medium and YPD medium, respectively, before total RNA was isolated. (A) qRT-PCR measurements detected a strong upregulation of <i>cdCSP1</i> and <i>cdCSP2</i> gene expression levels in <i>C. dubliniensis</i> during growth in Staib versus YPD medium. (B) Similarly, the <i>C. albicans</i> homologues <i>caCSP1</i> and <i>caCSP2</i> were found to be upregulated in the chlamydospore producing <i>C. albicans nrg1</i>Δ mutant stronger than in <i>C. albicans</i> wild-type yeast cells. The results are the means ±SD from three biological replicates, ‘*’ indicates that the detected differences were significant (<i>P</i><0.05).</p
Delay of Systemic Therapy Confers a Survival Benefit in Patients with Stage IV Non-Small-Cell Lung Cancer
No full textBackground: A timely systemic therapy of patients with metastasized non-small-cell lung cancer (NSCLC) is a suggestive clinical conception. As the pre-therapeutic management is complex and includes comprehensive immunohistochemical and molecular diagnostics, the time to optimal therapy may be prolonged. Whether the timing of therapy influences the outcome still remains controversial. We investigated the therapy timing and overall survival in subgroups of NSCLC patients in the clinical cancer registry of Lower Saxony. Materials and Methods: Patients with UICC stage IV NSCLC and systemic therapy were included. Early and delayed therapy groups based on the median time from histology to therapy were defined. Median overall survival (mOS) was estimated by the Kaplan–Meier test and compared by the log rank test. Uni- and multivariate Cox regression analyses were used for independent variables. Subgroup analyses were performed according to age, ECOG-PS, metastasis stage (M1a-c) and therapy. Results: We included 1687 patients; of these, the median age was 66.8 years, and 58% of patients were male. The median time to systemic therapy was 33 days, and in our sample, 844 patients were in the early and 843 in the delayed therapy group (TG). Median overall survival of the early TG patients was 9 m vs. 14 m in the delayed TG (p < 0.001). Subgroup analyses confirmed consistent findings among different age, metastasis and ECOG subgroups. Conclusions: UICC IV NSCLC patients with a delayed systemic therapy had a better overall survival than those with an early therapy. This observation supports a (qualified) waiting time for systemic therapies. Therapy timing may also be a relevant confounder in clinical studies
Cellular responses of Candida albicans to phagocytosis and the extracellular activities of neutrophils are critical to counteract carbohydrate starvation, oxidative and nitrosative stress
No full textAcknowledgments We thank Alexander Johnson (yhb1D/D), Karl Kuchler (sodD/D mutants), Janet Quinn (hog1D/D, hog1/cap1D/D, trx1D/D) and Peter Staib (ssu1D/D) for providing mutant strains. We acknowledge helpful discussions with our colleagues from the Microbial Pathogenicity Mechanisms Department, Fungal Septomics and the Microbial Biochemistry and Physiology Research Group at the Hans Kno¨ll Institute (HKI), specially Ilse D. Jacobsen, Duncan Wilson, Sascha Brunke, Lydia Kasper, Franziska Gerwien, Sea´na Duggan, Katrin Haupt, Kerstin Hu¨nniger, and Matthias Brock, as well as from our partners in the FINSysB Network. Author Contributions Conceived and designed the experiments: PM HW IMB AJPB OK BH. Performed the experiments: PM CD HW. Analyzed the data: PM HW IMB AJPB OK BH. Wrote the paper: PM HW OK AJPB BH.Peer reviewe
Monitoring von Informationsportalen zur Erkennung von kompromittierten Organisationen
No full textZiel der Bachelorarbeit ist die Entwicklung einer Anwendung, welche zum Monitoring von Informationsportalen zur Erkennung von kompromittierten Organisationen eingesetzt werden kann. Im Konkreten bezieht sich die Anwendung auf das Informationsportal Pastebin, welches nach Mustern, die vom Anwender bereitgestellt werden, durchsucht wird. Der Monitoring-Prozess soll in Form eines Prototyps umgesetzt werden. Bei Erkennung einer kompromittierten Organisation soll ein Alarm ausgelöst werden. Die Verarbeitung solcher Alarme beziehungsweise die Information betroffener Organisationen ist anschließend Aufgabe nachgelagerter Prozesse.The objective of this bachelor thesis is the development of an application for monitoring information portals in order to detect compromised organisations. In particular, the application relates to the information portal Pastebin, which is searched for user-specified patterns. The monitoring process is implemented in the form of a prototype. Detecting a compromised organization triggers an alarm. The processing of such an alarm and the information of the corresponding organisation is subsequently handled by downstream mechanisms
Detection and visualization of vulnerable systems based on passive logged network data
No full textIn dieser Arbeit wird ein Prototyp entwickelt, welcher unverschlüsselten Netzwerkverkehr passiv aufzeichnen, anschließend die aufgezeichneten Daten auswerten und die Ergebnisse der Auswertung anzeigen kann. Die Daten werden hierbei mithilfe von Sensoren gesammelt und mit einer Konsolenanwendung ausgewertet und angezeigt. Mit den Sensoren wird versucht, aus dem Netzwerkverkehr die Daten der Anwendungsschicht herauszufiltern. Wenn dies möglich ist, wird versucht, aus diesen Daten Servicenamen und -versionen der jeweiligen Anwendungsschichtprogramme zu extrahieren. Ist auch dies möglich, werden nun die extrahierten Servicenamen und -versionen gegen eine CVE-Datenbank geprüft. Somit können verwundbare Services, also solche, die Schwachstellen enthalten, erkannt werden. Anschließend werden die Ergebnisse der Prüfung angezeigt.In this thesis a prototype is developed, which passively records clear text network data, subsequently evaluates the recorded data and shows the results of the evaluation. The network data is recorded by sensors, the evaluation and the display of the results is done by a console application. The purpose is to filter application-layer data from the network data with the sensors. If this is possible, it is attempted to extract service names and versions from each application-layer software. If this also is possible, the extracted service names and versions are checked against a CVE-database. Therefore it is possible to detect vulnerable services. Afterwards the results of the CVE-check are displayed
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