Effect of Conventional Mouthrinses on Initial Bioadhesion to Enamel and Dentin in situ

Aim: The study aimed to investigate the effect of a customary fluoride solution, containing sodium fluoride and amine fluoride, on initial biofilm formation on enamel and dentin in situ compared directly to chlorhexidine. Methods: Bovine enamel and dentin specimens were mounted on maxillary splints carried by 9 subjects. After 1 min of pellicle formation, rinses with tap water (control), chlorhexidine (meridol med CHX 0.2%, GABA) and a fluoride mouthrinse (elmex, GABA) were performed for 1 min. Subsequently, the slabs were carried for another 8 h. The adherent bacteria were determined by DAPI staining, live-dead staining and determination of colony-forming units after desorption; glucan formation was visualized with concanavalin A. Additionally, energy-dispersive X-ray spectroscopy (EDX) analysis of the in situ biofilm layers was conducted, and contact angle measurements were performed. Statistical evaluation was performed by means of the Kruskal-Wallis test followed by the Mann-Whitney U test (p < 0.05). Results: In the control group, significantly higher amounts of adherent bacteria were detected on dentin (4.8 x 10⁶ ± 5.4 x 10⁶ bacteria/cm²) than on enamel (1.2 x 10⁶ ± 1.5 x 10⁶ bacteria/cm² , DAPI). Chlorhexidine significantly reduced the amount of adherent bacteria (dentin: 2.8 x 10⁵ ± 3.4 x 10⁵ bacteria/cm² ; enamel: 4.2 x 10⁵ ± 8.7 x 10⁵ bacteria/cm²). Rinses with the fluoride solution also significantly reduced bacterial adherence to dentin (8.1 x 10⁵ ± 1.5 x 10⁶ bacteria/cm²). Fluoride could not be detected by EDX analysis of the biofilms. Fluoride mouthrinsing did not influence the wettability of the pellicle-covered enamel surface. Conclusion: In addition to the reduction of demineralization and antibacterial effects, fluorides inhibit initial biofilm formation on dental hard tissues considerably, especially on dentin

Psychische Störungen bei solistisch tätigen Opernsängern:Prävalenz, Selbsteinschätzung und Handlungsstrategien der Sänger

Ziel der vorliegenden Arbeit war die Erhebung der Prävalenz psychischer Störungen, möglicher Gründe und Faktoren für psychische Störungen und die Selbsteinschätzung von solistisch tätigen Opernsängen. Dazu wurde eine postalische Vollerhebung der in Nordrhein-Westfalen tätigen Opernsänger durchgeführt. Das Untersuchungsinstrument wurde neu entwickelt, wobei der GHQ 12, ein Screeninginstrument für psychische Störungen, integriert wurde. Bei mehr als einem Viertel der untersuchten Sänger ergab sich ein Verdacht auf das Vorliegen einer psychischen Störung. Jüngere Sänger waren dabei signifikant häufiger auffällig als ältere, Frauen häufiger als Männer. Psychische Störungen kamen gehäuft bei Befragten mit unsicherer Arbeitsplatzsituation vor, einem hohen Leistungsideal und geringer Zufriedenheit mit den eigenen Leistungen. Berufliche Belastungen und die Arbeitsplatzunsicherheit scheinen sich negativ auf die psychische Gesundheit der Sänger auszuwirken

THE POLARITY OF THE PROXIMAL TUBULE CELL IN RAT KIDNEY : Different Surface Charges for the Brush-Border Microvilli and Plasma Membranes from the Basal Infoldings

Two different membrane fractions were obtained from a brush-border fraction of rat kidney cortex by using their different electrical surface charges in preparative free-flow electrophoresis. One membrane fraction contained only morphologically intact microvilli and was characterized by a high specific activity of alkaline phosphatase. The other fraction morphologically resembled classical plasma membranes by possessing junctional complexes and a high Na-K-ATPase activity The contamination of the isolated membrane fractions by other cell organelles was extremely low These two fractions represent the apical (luminal) and the basal (interstitial) area of the renal proximal tubule cell membrane and clearly demonstrate the polarity of this cell

Hydroxyapatite-Based Solution as Adjunct Treatment for Biofilm Management: An In Situ Study

Synthetic hydroxyapatite-based solution is a bioinspired material that may present antiadhesive properties, restraining the dental biofilm formation without causing adverse effects. This in situ study aims to evaluate the effects of three different hydroxyapatite (HAP) watery solutions as a mouthwash against biofilm adhesion on different dental material surfaces under oral conditions. Hence, four volunteers carried maxillary splints containing enamel, titanium, ceramics, and polymethyl-methacrylate resin (PMMA) samples. Three HAP watery solutions (5%) were prepared with HAP particles presenting different shapes and sizes (HAP I, HAP II, HAP III). During 24 h, the volunteers rinsed two times with one of the following selected tested solution: HAP I, HAP II, HAP III, water, or chlorhexidine 0.2% (CHX). The first rinse was performed 3 min after pellicle formation; the second rinse occurred after a 12 h interval. The surface analysis was performed by scanning electron microscopy (SEM), fluorescence microscopy (FM), and transmission electron microscopy (TEM). Statistical and microscopic analysis showed that most samples treated with any HAP solution revealed reduced biofilm coverage presenting comparable results to CHX treated samples, however without altering the microorganisms’ viability. In conclusion, the results of this investigation showed that a pure hydroxyapatite-based mouthrinse could be a promising bioinspired adjunct solution for biofilm management

Inferential models: A framework for prior-free posterior probabilistic inference

Posterior probabilistic statistical inference without priors is an important but so far elusive goal. Fisher's fiducial inference, Dempster-Shafer theory of belief functions, and Bayesian inference with default priors are attempts to achieve this goal but, to date, none has given a completely satisfactory picture. This paper presents a new framework for probabilistic inference, based on inferential models (IMs), which not only provides data-dependent probabilistic measures of uncertainty about the unknown parameter, but does so with an automatic long-run frequency calibration property. The key to this new approach is the identification of an unobservable auxiliary variable associated with observable data and unknown parameter, and the prediction of this auxiliary variable with a random set before conditioning on data. Here we present a three-step IM construction, and prove a frequency-calibration property of the IM's belief function under mild conditions. A corresponding optimality theory is developed, which helps to resolve the non-uniqueness issue. Several examples are presented to illustrate this new approach.Comment: 29 pages with 3 figures. Main text is the same as the published version. Appendix B is an addition, not in the published version, that contains some corrections and extensions of two of the main theorem

Poly(alkyl methacrylate) tooth coatings for dental care: evaluation of the demineralisation-protection benefit using a time-resolved in vitro method

An in vitro method for the time-resolved quantification of acid-mediated tooth demineralisation has been developed and evaluated against putative non-permanent protective formulations based on a series of poly(alkyl methacrylate)s. Using a thermostatted carousel, dentally relevant substrates consisting of hydroxyapatite discs or sections of bovine teeth have been exposed to aqueous citric acid under controlled conditions, before and after being treated with the polymeric coatings. The dissolution of phosphate was monitored by the determination of 31P by Inductively Coupled Plasma—Mass Spectrometry and by the spectrophotometric phosphovanadomolybdate method. Dose-response plots constructed for both groups of treated substrates have revealed that the coatings significantly reduce erosion rates but are less effective at inhibiting tooth demineralisation than the standard fluoride treatment. The approach has enabled an evaluation of the erosion-protection efficiency of each coating

Guanylate cyclase-C/cGMP: an emerging pathway in the regulation of visceral pain

Activation of guanylate cyclase-C (GC-C) expressed predominantly on intestinal epithelial cells by guanylin, uroguanylin or the closely related GC-C agonist peptide, linaclotide, stimulates generation and release of cyclic guanosine-3’,5’-monophosphate (cGMP). Evidence that the visceral analgesic effects of linaclotide are mediated by a novel, GC-C-dependent peripheral sensory mechanism was first demonstrated in animal models of visceral pain. Subsequent studies with uroguanylin or linaclotide have confirmed the activation of a GC-C/cGMP pathway leading to increased submucosal cGMP mediated by cGMP efflux pumps, which modulates intestinal nociceptor function resulting in peripheral analgesia. These effects can be reproduced by the addition of exogenous cGMP and support a role for GC-C/cGMP signaling in the regulation of visceral sensation, a physiological function that has not previously been linked to the GC-C/cGMP pathway. Notably, targeting the GC-C/cGMP pathway for treatment of gastrointestinal pain and abdominal sensory symptoms has now been validated in the clinic. In 2012, linaclotide was approved in the United States and European Union for the treatment of adult patients with irritable bowel syndrome with constipation