2,3,7,8-Tetrachlorodibenzo-p-dioxin alters steroid secretion but does not affect cell viability and the incidence of apoptosis in porcine luteinised granulosa cells

The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a by-product of human industrial activity, was found to affect ovarian steroidogenesis in animals, but the mechanism of its action is still unclear. The aims of the study were to examine the effect of TCDD on (1) progesterone (P4) and oestradiol (E2) production by granulosa cells isolated from medium (3–6 mm) and preovulatory (≥ 8 mm) porcine follicles, (2) the viability of the cells, and (3) the incidence of apoptosis. Porcine granulosa cells were cultured (48 h) with or without TCDD (100 pM, 100 nM). Steroid hormone concentrations in the medium were determined by radioimmunoassay. The viability of granulosa cells was tested spectrophotometrically (alamarBlue™ assay). Apoptosis was evaluated by flow cytometry using Annexin V and by TUNEL assay. The higher dose of TCDD (100 nM) significantly inhibited P4 and stimulated E2 production by luteinised granulosa cells isolated from medium follicles. The lower dose of TCDD (100 pM) significantly stimulated P4 and inhibited E2 secretion by the cells isolated from preovulatory follicles. None of the two TCDD doses affected cell viability or induced apoptosis in granulosa cells. In conclusion, TCDD directly affected steroid production by granulosa cells obtained from mature pigs, but the effect of TCDD was not due to its cytotoxicity

An In Vitro Pipeline for Screening and Selection of Citrus-Associated Microbiota with Potential Anti-"Candidatus Liberibacter asiaticus" Properties.

Huanglongbing (HLB) is a destructive citrus disease that is lethal to all commercial citrus plants, making it the most serious citrus disease and one of the most serious plant diseases. Because of the severity of HLB and the paucity of effective control measures, we structured this study to encompass the entirety of the citrus microbiome and the chemistries associated with that microbial community. We describe the spatial niche diversity of bacteria and fungi associated with citrus roots, stems, and leaves using traditional microbial culturing integrated with culture-independent methods. Using the culturable sector of the citrus microbiome, we created a microbial repository using a high-throughput bulk culturing and microbial identification pipeline. We integrated an in vitro agar diffusion inhibition bioassay into our culturing pipeline that queried the repository for antimicrobial activity against Liberibacter crescens, a culturable surrogate for the nonculturable "Candidatus Liberibacter asiaticus" bacterium associated with HLB. We identified microbes with robust inhibitory activity against L. crescens that include the fungi Cladosporium cladosporioides and Epicoccum nigrum and bacterial species of Pantoea, Bacillus, and Curtobacterium Purified bioactive natural products with anti-"Ca. Liberibacter asiaticus" activity were identified from the fungus C. cladosporioides Bioassay-guided fractionation of an organic extract of C. cladosporioides yielded the natural products cladosporols A, C, and D as the active agents against L. crescens This work serves as a foundation for unraveling the complex chemistries associated with the citrus microbiome to begin to understand the functional roles of members of the microbiome, with the long-term goal of developing anti-"Ca Liberibacter asiaticus" bioinoculants that thrive in the citrus holosystem.IMPORTANCE Globally, citrus is threatened by huanglongbing (HLB), and the lack of effective control measures is a major concern of farmers, markets, and consumers. There is compelling evidence that plant health is a function of the activities of the plant's associated microbiome. Using Liberibacter crescens, a culturable surrogate for the unculturable HLB-associated bacterium "Candidatus Liberibacter asiaticus," we tested the hypothesis that members of the citrus microbiome produce potential anti-"Ca Liberibacter asiaticus" natural products with potential anti-"Ca Liberibacter asiaticus" activity. A subset of isolates obtained from the microbiome inhibited L. crescens growth in an agar diffusion inhibition assay. Further fractionation experiments linked the inhibitory activity of the fungus Cladosporium cladosporioides to the fungus-produced natural products cladosporols A, C, and D, demonstrating dose-dependent antagonism to L. crescens

Comparative transcriptomic and proteomic signature of lung alveolar macrophages reveals the integrin CD11b as a regulatory hub during pneumococcal pneumonia infection

IntroductionStreptococcus pneumoniae is one of the main causes of community-acquired infections in the lung alveoli in children and the elderly. Alveolar macrophages (AM) patrol alveoli in homeostasis and under infectious conditions. However, the molecular adaptations of AM upon infections with Streptococcus pneumoniae are incompletely resolved.MethodsWe used a comparative transcriptomic and proteomic approach to provide novel insights into the cellular mechanism that changes the molecular signature of AM during lung infections. Using a tandem mass spectrometry approach to murine cell-sorted AM, we revealed significant proteomic changes upon lung infection with Streptococcus pneumoniae.ResultsAM showed a strong neutrophil-associated proteomic signature, such as expression of CD11b, MPO, neutrophil gelatinases, and elastases, which was associated with phagocytosis of recruited neutrophils. Transcriptomic analysis indicated intrinsic expression of CD11b by AM. Moreover, comparative transcriptomic and proteomic profiling identified CD11b as the central molecular hub in AM, which influenced neutrophil recruitment, activation, and migration.DiscussionIn conclusion, our study provides novel insights into the intrinsic molecular adaptations of AM upon lung infection with Streptococcus pneumoniae and reveals profound alterations critical for effective antimicrobial immunity

Misregulation of the LOB domain gene DDA1 suggests possible functions in auxin signalling and photomorphogenesis

The LATERAL ORGAN BOUNDARIES DOMAIN (LBD) gene family encodes plant-specific transcription factors. In this report, the LBD gene DOWN IN DARK AND AUXIN1 (DDA1), which is closely related to LATERAL ORGAN BOUNDARIES (LOB) and ASYMMETRIC LEAVES2 (AS2), was characterized. DDA1 is expressed primarily in vascular tissues and its transcript levels were reduced by exposure to exogenous indole-3-acetic acid (IAA or auxin) and in response to dark exposure. Analysis of a T-DNA insertion line, dda1-1, in which the insertion resulted in misregulation of DDA1 transcripts in the presence of IAA and in the dark revealed possible functions in auxin response and photomorphogenesis. dda1-1 plants exhibited reduced sensitivity to auxin, produced fewer lateral roots, and displayed aberrant hypocotyl elongation in the dark. Phenotypes resulting from fusion of a transcriptional repression domain to DDA1 suggest that DDA1 may act as both a transcriptional activator and a transcriptional repressor depending on the context. These results indicate that DDA1 may function in both the auxin signalling and photomorphogenesis pathways

Seroprevalence of 34 Human Papillomavirus Types in the German General Population

The natural history of infections with many human papillomavirus (HPV) types is poorly understood. Here, we describe for the first time the age- and sex-dependent antibody prevalence for 29 cutaneous and five mucosal HPV types from 15 species within five phylogenetic genera (alpha, beta, gamma, mu, nu) in a general population. Sera from 1,797 German adults and children (758 males and 1,039 females) between 1 and 82 years (median 37 years) were analysed for antibodies to the major capsid protein L1 by Luminex-based multiplex serology. The first substantial HPV antibody reactions observed already in children and young adults are those to cutaneous types of the genera nu (HPV 41) and mu (HPV 1, 63). The antibody prevalence to mucosal high-risk types, most prominently HPV 16, was elevated after puberty in women but not in men and peaked between 25 and 34 years. Antibodies to beta and gamma papillomaviruses (PV) were rare in children and increased homogeneously with age, with prevalence peaks at 40 and 60 years in women and 50 and 70 years in men. Antibodies to cutaneous alpha PV showed a heterogeneous age distribution. In summary, these data suggest three major seroprevalence patterns for HPV of phylogenetically distinct genera: antibodies to mu and nu skin PV appear early in life, those to mucosal alpha PV in women after puberty, and antibodies to beta as well as to gamma skin PV accumulate later in life

Zu einer Raumkurve assoziierte Flächen. Ein neuer Beweis der Fabricius-Bjerre-Formel

Fabricius-Bjerre fand eine sehr elegante Formel, die eine Relation zwischen geometrischen Eigenschaften von generischen geschlossenen ebenen Kurven darstellt. Unter bitangentialen Geraden, d.h. Geraden, die eine Kurve an zwei Punkten berühren, werden zwei Typen unterschieden: externe, wenn die Kurve lokal auf einer Seite der Geraden liegt und interne andernfalls. Die Fabricius-Bjerre Formel besagt: Die Anzahl von externen bitangentialen Geraden ist gleich der Summe von der Anzahl von internen bitangentialen Geraden, der Anzahl der Doppelpunkte und der Hälfte von der Anzahl von Wendepunkten der ebenen Kurve. In dieser Dissertation, wird die Formel von bitangentialen Geraden zu Paaren von parallelen Tangenten generalisiert. Das Hauptresultat ist allerdings ein neuer Beweis der Fabricius-Bjerre Formel, der neue Methoden verwendet. Die Idee ist eine ebene Kurve als Projektion einer Raumkurve zu betrachten. Es wird ein Zusammenhang entwickelt zwischen generischen ebenen Kurven und Projektionen von einer Klasse der generischen Raumkurven in Euklidischen 3-Raum. Zu einer Raumkurve werden jeweils drei Flächen konstruiert, mit einer Abbildung zu der 2-Sphäre. Diese Objekte enthalten Informationen über die Variablen aus der Fabricius-Bjerre Formel für alle Projektionen der Raumkurve. Es wird gezeigt, dass sich diese drei Flächen durch vorherige geeignete Umstrukturierung zusammenkleben lassen. Als Resultat entsteht eine geschlossene Fläche mit einer natürlichen Abbildung zu der Sphäre, deren Grad in engem Zusammenhang zu der Fabricius-Bjerre Formel steht. Auf diese Weise wird eine Äquivalenz zwischen der Fabricius-Bjerre Formel und der Tatsache, dass der Grad der konstruierten Abbildung für jede Raumkurve verschwindet, entwickelt. Das letztere wird dann mit Methoden von Arnold bewiesen. Eine Anwendung des neuen Ansatzes ist die integrale Version der Fabricius-Bjerre Formel. Die hier entwickelten Methoden liefern außerdem einen neuen Beweis einer Formel von Banchoff und Aicardi für die Selbstverschlingungszahl einer geschlossenen Raumkurve. Es scheint, dass viele ähnliche Formeln für die ebenen Kurven sich mit analogen Methoden beweisen lassen.In 1962 Fabricius-Bjerre found a formula relating certain geometric features of generic closed plane curves. Among bitangent lines, i.e., lines that are tangent to a curve at two points, distinguish two types: external - if the arcs of tangency lie on the same side of the line - and internal otherwise. Then, there is the following equality: the number of external bitangent lines equals the sum of the number of internal bitangent lines, the number of crossings and half of the number of inflection points of the plane curve. Two different proofs of the formula followed, by Halpern in 1970 and Banchoff in 1974, as well as many generalizations. Halpern's approach is used here to provide a generalization from bitangent lines to parallel tangents pairs. The main result of this thesis is a new proof of Fabricius-Bjerre's Theorem, which uses new methods. The idea is to view a plane curve as a projection of a space curve. The proof establishes a connection between the generic plane curves and the projections of a certain class of generic closed space curves. For a closed space curve three surfaces are constructed with maps to the sphere of projection directions. These maps encode the information of the variables appearing in the Fabricius-Bjerre formula for each projection. The surfaces are glued together to form a closed surface with a naturally defined continuous map to the sphere. The degree of that map turns out to be equal to the expression arising when all variables of the Fabricius-Bjerre formula (for a plane curve which is a projection of the space curve) are put on one side of the equality. Using methods similar to those of V.I. Arnold (used to define J and St invariants), it is proved that the degree of the constructed map is zero for any generic space curve. An equivalence between the latter and Fabricius-Bjerre's Theorem is established. This gives a new proof of the theorem. The methods developed in this thesis have numerous possible applications. First, the integral version of the Fabricius-Bjerre formula is obtained which states that the average bitangency number equals the sum of the average crossing number and the average absolute torsion of a generic space curve. Another application is a new proof of the formula of Banchoff and Aicardi that expresses the self-linking number of a closed space curve as a sum of the writhe of a diagram and half of the signs of torsion at points of the space curve that project to inflection points in the diagram. It seems that using the methods of this work, nearly any formula relating some geometric features of a plane curve, as for example, the generalization to parallel tangents pairs, can be proved. Also, the generalization of the formula by Fabricius-Bjerre to curves with cusps finds a new geometric interpretation with the new approach