Oral microbiota in Swiss adolescents

OBJECTIVES: The purpose of the study was to determine the prevalence of different oral microbes in gingival plaque samples and in samples from the dorsum of the tongue in a Swiss adolescent population. MATERIALS AND METHODS: Ninety-nine adolescents between 15 and 18 years were enrolled. Plaque index, bleeding on probing (BOP), the periodontal screening index, and decayed missed filled tooth (DMFT) index were recorded. Samples from subgingival plaque and swabs from the tongue were analyzed by the Checkerboard DNA-DNA hybridization method. Additionally, counts of Streptococus mutans and Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were determined by real-time PCR. RESULTS: Periodontitis was not diagnosed in any of the subjects but all of them presented signs of gingival inflammation displaying a mean BOP of 28%. Ten (10.1%) subjects were tested positive for P. gingivalis, each 22 (22.2%) for A. actinomycetemcomitans and T. forsythia, (47.5%) for T. denticola. T. denticola and S. mutans showed a high affinity to the gingival plaque, whereas T. forsythia was often detected from the dorsum of the tongue. DMFT was associated with S. mutans counts, and BOP correlated with counts of P. gingivalis and T. denticola. CONCLUSIONS: The present data indicate that: (a) gingivitis but not periodontitis is a common finding among Swiss adolescents, and (b) bacteria associated with periodontitis were frequently detected in the subgingival dental plaque and on the dorsum of the tongue in Swiss adolescents with gingivitis. CLINICAL RELEVANCE: Although gingivitis was a frequent finding in Swiss adolescents, periodontitis was not detected in this population. The dorsum of the tongue appears to represent an important reservoir for periodontopathic bacteria.

Inhibition of FcepsilonRI-dependent mediator release and calcium flux from human mast cells by sialic acid-binding immunoglobulin-like lectin 8 engagement

BACKGROUND: Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of glycan-binding inhibitory receptors, and among them, Siglec-8 is selectively expressed on human eosinophils, basophils, and mast cells. On eosinophils, Siglec-8 engagement induces apoptosis, but its function on mast cells is unknown. OBJECTIVE: We sought to study the effect of Siglec-8 engagement on human mast cell survival and mediator release responses. METHODS: Human mast cells were generated from CD34+ precursors. Apoptosis was studied by using flow cytometry. Mast cell mediator release or human lung airway smooth muscle contraction was initiated by FcepsilonRI cross-linking with or without preincubation with Siglec-8 or control antibodies, and release of mediators was analyzed along with Ca++ flux. RBL-2H3 cells transfected with normal and mutated forms of Siglec-8 were used to study how Siglec-8 engagement alters mediator release. RESULTS: Siglec-8 engagement failed to induce human mast cell apoptosis. However, preincubation with Siglec-8 mAbs significantly (P < .05) inhibited FcepsilonRI-dependent histamine and prostaglandin D(2) release, Ca++ flux, and anti-IgE-evoked contractions of human bronchial rings. In contrast, release of IL-8 was not inhibited. Siglec-8 ligation was also shown to inhibit beta-hexosaminidase release and Ca++ flux triggered through FcepsilonRI in RBL-2H3 cells transfected with full-length human Siglec-8 but not in cells transfected with Siglec-8 containing a tyrosine to phenylalanine point mutation in the membrane-proximal immunoreceptor tyrosine-based inhibitory motif domain. CONCLUSION: These data represent the first reported inhibitory effects of Siglec engagement on human mast cells.

Die sonographische Inzidenz der ungewundenen Nabelschnur im Verlauf der Schwangerschaft

Einleitung: Pathologische Untersuchungen haben gezeigt, dass ungewundene Nabelschnüre gehäuft im Zusammenhang mit Frühaborten, beim plötzlichen intrauterinen Tod, Aneuploidien, Strukturdefekten und fetal distress vorkommen. Aus diesem Grund erscheint es wichtig, auch die Angioarchitektur der Nabelschnur im Rahmen der antenatalen Sonographie zu beurteilen. Angaben zur sonographischen Inzidenz solch ungewundener Nabelschnüre im Normalkollektiv liegen jedoch nicht vor. Material und Methode: Es wurden konsekutiv Frauen mit Einlingsschwangerschaften und normalen Feten für die Studie ausgewählt, wobei jede Schwangere nur einmal eingeschlossen wurde. Das Aufsuchen der Nabelschnurgefässe wurde durch den Einsatz der Farbdoppler-Methode erleichtert. Eine Nabelschnur wurde als ungewunden definiert, wenn die Umbilikalgefässe parallel zueinander verliefen. Die Inzidenz der ungewundenen Nabelschnur wurde im zweiwöchentlichen Intervall kalkuliert. Die statistischen Auswertung erfolgte mittels der Spearman rank correlation. Ergebnisse: Insgesamt wurden 340 Frauen mit einem mittleren Gestationsalter (range) von 17,5 (7,2–40,1) Wochen eingeschlossen. Die Gesamtinzidenz ungewundener Nabelschnüre betrug in unserem Kollektiv 13,5%. Es zeigte sich eine signifikante Korrelation zwischen dem Gestationsalter und der Inzidenz ungewundener Nabelschnüre (r = –0,65 [95% CI –0,87 bis –0,23]; p ! 0,01). Unter 8 Schwangerschaftswochen zeigten 85,7% der Fälle eine ungewundene Nabelschnur. Diese Inzidenz verringert sich drastisch mit Fortschreiten der Schwangerschaft. Nach 14 Schwangerschaftswochen wurden nur noch 9,6 8 5,8% der Nabelschnüre als ungewunden klassifiziert. Schlussfolgerung: Die Morphologie der Nabelschnur zeigt in Abhängigkeit vom Gestationsalter markante Veränderungen. Dies gilt besonders für das erste Trimenon, in welchem sich das Erscheinungsbild der Nabelschnurgefässe rasch von einem prädominant parallelen zu dem typisch gewundenen verändert. Es ist überaus interessant, dass diese Art der Reifung der Nabelschnurmorphologie gleichzeitig mit anderen wichtigen Ereignissen geschieht, wie z.B. der Formation des intervillösen Raumes und dem Erscheinen der diastolischen Doppler-Flussgeschwindigkeiten in den Umbilicalarterien.

Non-invasive measurement of steroids in fish-holding water: important considerations when applying the procedure to behaviour studies

Fish behaviourists are increasingly turning to non-invasive measurement of steroid hormones in holding water, as opposed to blood plasma. When some of us met at a workshop in Faro, Portugal, in September, 2007, we realised that there were still many issues concerning the application of this procedure that needed resolution, including: Why do we measure release rates rather than just concentrations of steroids in the water? How does one interpret steroid release rates when dealing with fish of different sizes? What are the merits of measuring conjugated as well as free steroids in water? In the ‘static’ sampling procedure, where fish are placed in a separate container for a short period of time, does this affect steroid release—and, if so, how can it be minimised? After exposing a fish to a behavioural stimulus, when is the optimal time to sample? What is the minimum amount of validation when applying the procedure to a new species? The purpose of this review is to attempt to answer these questions and, in doing so, to emphasize that application of the non-invasive procedure requires more planning and validation than conventional plasma sampling. However, we consider that the rewards justify the extra effort.

Ohne Titel

Das vorliegende Heft beinhaltet drei Vorträge der Vorlesungsreihe ‹Das Mittelmeer – Mare nostrum?›, die das Berner Mittelalterzentrum im Frühjahrssemester 2012 durchführte. Dabei wurden aus der jeweiligen Perspektive der beteiligten Disziplinen unterschiedliche Aspekte angesprochen, die in Korrelation mit diversen Begriffen standen, durch die das Mittelmeer seit der Antike bezeichnet wurde: vom ‹Großen Grün› im alten Ägypten zum ‹Mare Nostrum› in der römischen Antike, vom ‹Grossen Meer› der Juden im Mittelalter bis zum provokanten Titel ‹Corrupting Sea› in der jüngeren Forschung. Seit Fernand Braudel wurde der Mittelmeerraum als eine Einheit in der Vielfalt beschrieben. Während der französische Gelehrte Historie noch als eine Geschichte ‹ohne Namen› verstand und die kulturellen Verflechtungen, Überlagerungen und Gegensätze der nördlichen und südlichen Anrainerstaaten des Mittelmeers aus der jeweiligen landschaftlichen und geopolitischen Situation abzuleiten vermochte, neigt die jüngere Forschung dazu, diese Entwicklungen unter sozialhistorischen und anthropologischen Gesichtspunkten zu erklären, die von Menschen und deren kulturellem Austausch handeln. Eine Kulturanthropologie des Mittelmeers verschreibt sich der Aufdeckung und Analyse von Verhaltenskulturen an den Rändern kultureller Zentren. Dabei wird ‹Rand› nicht als eindimensionale Grenzlinie, sondern als Summe topographisch beschreibbarer Kulturräume jenseits staatlicher Beschränkungen verstanden. Der Beitrag von Jean-Marie Martin (CNRS, ehemals Ecole française de Rome) befasst sich unter diesem Aspekt mit der Rolle Siziliens und seiner geographischen Lage zwischen Italien und Afrika im Zeitraum von der byzantinischen zur staufischen Herrschaft. Stephan Conermann (Universität Bonn) behandelt die Mamlukenherrschaft in Ägypten und Syrien und setzt dabei Maßstäbe für eine globalgeschichtliche Betrachtungsweise. Beschlossen wird die Reihe der Beiträge von Arnold Esch (ehemals Direktor des Deutschen Historischen Instituts in Rom), der mit der ihm eigenen Kunst historischer Vergegenwärtigung eine verbindende Betrachtung der Kommunikations- und Handelswege im Mittelmeerraum des 15. Jahrhunderts leistet.

Flavor-phenomenology of two-Higgs-doublet models with generic Yukawa structure

In this article, we perform an extensive study of flavor observables in a two-Higgs-doublet model with generic Yukawa structure (of type III). This model is interesting not only because it is the decoupling limit of the minimal supersymmetric standard model but also because of its rich flavor phenomenology which also allows for sizable effects not only in flavor-changing neutral-current (FCNC) processes but also in tauonic B decays. We examine the possible effects in flavor physics and constrain the model both from tree-level processes and from loop observables. The free parameters of the model are the heavy Higgs mass, tanβ (the ratio of vacuum expectation values) and the “nonholomorphic” Yukawa couplings ϵfij(f=u,d,ℓ). In our analysis we constrain the elements ϵfij in various ways: In a first step we give order of magnitude constraints on ϵfij from ’t Hooft’s naturalness criterion, finding that all ϵfij must be rather small unless the third generation is involved. In a second step, we constrain the Yukawa structure of the type-III two-Higgs-doublet model from tree-level FCNC processes (Bs,d→μ+μ−, KL→μ+μ−, D¯¯¯0→μ+μ−, ΔF=2 processes, τ−→μ−μ+μ−, τ−→e−μ+μ− and μ−→e−e+e−) and observe that all flavor off-diagonal elements of these couplings, except ϵu32,31 and ϵu23,13, must be very small in order to satisfy the current experimental bounds. In a third step, we consider Higgs mediated loop contributions to FCNC processes [b→s(d)γ, Bs,d mixing, K−K¯¯¯ mixing and μ→eγ] finding that also ϵu13 and ϵu23 must be very small, while the bounds on ϵu31 and ϵu32 are especially weak. Furthermore, considering the constraints from electric dipole moments we obtain constrains on some parameters ϵu,ℓij. Taking into account the constraints from FCNC processes we study the size of possible effects in the tauonic B decays (B→τν, B→Dτν and B→D∗τν) as well as in D(s)→τν, D(s)→μν, K(π)→eν, K(π)→μν and τ→K(π)ν which are all sensitive to tree-level charged Higgs exchange. Interestingly, the unconstrained ϵu32,31 are just the elements which directly enter the branching ratios for B→τν, B→Dτν and B→D∗τν. We show that they can explain the deviations from the SM predictions in these processes without fine-tuning. Furthermore, B→τν, B→Dτν and B→D∗τν can even be explained simultaneously. Finally, we give upper limits on the branching ratios of the lepton flavor-violating neutral B meson decays (Bs,d→μe, Bs,d→τe and Bs,d→τμ) and correlate the radiative lepton decays (τ→μγ, τ→eγ and μ→eγ) to the corresponding neutral current lepton decays (τ−→μ−μ+μ−, τ−→e−μ+μ− and μ−→e−e+e−). A detailed Appendix contains all relevant information for the considered processes for general scalar-fermion-fermion couplings.

On new maximal supergravity and its BPS domain-walls

We revise the SU(3)-invariant sector of N  = 8 supergravity with dyonic SO(8) gaugings. By using the embedding tensor formalism, analytic expressions for the scalar potential, superpotential(s) and fermion mass terms are obtained as a function of the electromagnetic phase ω and the scalars in the theory. Equipped with these results, we explore non-supersymmetric AdS critical points at ω ≠ 0 for which perturbative stability could not be analysed before. The ω-dependent superpotential is then used to derive first-order flow equations and obtain new BPS domain-wall solutions at ω ≠ 0. We numerically look at steepest-descent paths motivated by the (conjectured) RG flows.

Spontaneous supersymmetry breaking in the 2d N=1 Wess-Zumino model

We study the phase diagram of the two-dimensional N = 1 Wess-Zumino model using Wilson fermions and the fermion loop formulation. We give a complete non-perturbative determination of the ground state structure in the continuum and infinite volume limit. We also present a determination of the particle spectrum in the supersymmetric phase, in the supersymmetry broken phase and across the supersymmetry breaking phase transition. In the supersymmetry broken phase we observe the emergence of the Goldstino particle.

Dental Caries and Microbiota in Children with Black Stain and Non-discoloured Dental Plaque

Aim: We aimed to assess caries experience and microbiota in systemically healthy children with black stain (BS) and non-discoloured plaque. Methods: Forty-six children with BS and 47 counterparts with non-discoloured plaque aged 7.9 ± 1.3 years were clinically examined. Dental caries was scored using WHO criteria. Samples of BS and non-discoloured dental plaque were collected from tooth surfaces. The DNA of the samples was extracted and real-time PCR was performed to determine the total number of bacteria and the species Streptococcus mutans, S. sobrinus, Lactobacillus sp., Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum. Results: Children with BS had lower DMFT (p = 0.013), lower DT values (p = 0.005) and a tendency to lower caries prevalence (p = 0.061) than children with non-discoloured plaque. Plaque samples of the BS group contained higher numbers of A. naeslundii (p = 0.005) and lower numbers of F. nucleatum (p = 0.001) and Lactobacillus sp. (p = 0.001) compared to the non-discoloured plaque samples of the control group. Comparing the children with BS and non-discoloured plaque, higher counts for A. naeslundii (p = 0.013) were observed in caries-free children with BS while in caries-affected children with BS, lower counts of F. nucleatum (p = 0.007) were found. Counts of Lactobacillus sp. were higher in non-discoloured plaque samples than in BS of caries-free and caries-affected children. Conclusion: Results suggest that the different microbial composition of BS might be associated with the lower caries experience in affected subjects. The role of black-pigmented bacteria associated with periodontitis needs further studies. © 2013 S. Karger AG, Basel.