Vesicular Messages from Dental Biofilms for Neutrophils.

The encounter between dental biofilm and neutrophils in periodontitis remains elusive, although it apparently plays a crucial role in the periodontal pathology and constitutes a key topic of periodontology. Dental biofilm and neutrophils were isolated from orally healthy persons and patients with periodontitis. We investigated biofilm and its particle-shedding phenomenon with electron microscopy and nanoparticle tracking analysis (NTA); biofilm shedding-neutrophil interactions were examined ex vivo with epi-fluorescence microscopy.

Neutrophil extracellular trap (NET) formation characterises stable and exacerbated COPD and correlates with airflow limitation.

Background: COPD is a progressive disease of the airways that is characterized by neutrophilic inflammation, a condition known to promote the excessive formation of neutrophil extracellular traps (NETs). The presence of large amounts of NETs has recently been demonstrated for a variety of inflammatory lung diseases including cystic fibrosis, asthma and exacerbated COPD.

Objective: We test whether excessive NET generation is restricted to exacerbation of COPD or whether it also occurs during stable periods of the disease, and whether NET presence and amount correlates with the severity of airflow limitation.

The Role of Reactive Oxygen Species (ROS) in the Formation of Extracellular Traps (ETs) in Humans.

Extracellular traps (ETs) are reticulate structures of extracellular DNA associated with antimicrobial molecules. Their formation by phagocytes (mainly by neutrophils: NETs) has been identified as an essential element of vertebrate innate immune defense. However, as ETs are also toxic to host cells and potent triggers of autoimmunity, their role between pathogen defense and human pathogenesis is ambiguous, and they contribute to a variety of acute and chronic inflammatory diseases.

Free DNA in cystic fibrosis airway fluids correlates with airflow obstruction.

Chronic obstructive lung disease determines morbidity and mortality of patients with cystic fibrosis (CF). CF airways are characterized by a nonresolving neutrophilic inflammation. After pathogen contact or prolonged activation, neutrophils release DNA fibres decorated with antimicrobial proteins, forming neutrophil extracellular traps (NETs).

The initial inflammatory response to bioactive implants is characterized by NETosis.

Implants trigger an inflammatory response, which is important for osseointegration. Here we studied neutrophil extracellular trap (NET) release of human neutrophils in response to sandblasted large-grit acid etched (SLA) implants using fluorescent, confocal laser scanning and scanning electron microscopy. Our studies demonstrate that human neutrophils rapidly adhered to SLA surfaces, which triggered histone citrullination and NET release.

New aspects on the structure of neutrophil extracellular traps from chronic obstructive pulmonary disease and in vitro generation.

Polymorphonuclear neutrophils have in recent years attracted new attention due to their ability to release neutrophil extracellular traps (NETs). These web-like extracellular structures deriving from nuclear chromatin have been depicted in ambiguous roles between antimicrobial defence and host tissue damage. NETs consist of DNA strands of varying thickness and are decorated with microbicidal and cytotoxic proteins.

Neutrophils express distinct RNA receptors in a non-canonical way.

RNAs are capable of modulating immune responses by binding to specific receptors. Neutrophils represent the major fraction of circulating immune cells, but receptors and mechanisms by which neutrophils sense RNA are poorly defined. Here, we analyzed the mRNA and protein expression patterns and the subcellular localization of the RNA receptors RIG-I, MDA-5, TLR3, TLR7, and TLR8 in primary neutrophils and immortalized neutrophil-like differentiated HL-60 cells.

CXCR2 mediates NADPH oxidase-independent neutrophil extracellular trap formation in cystic fibrosis airway inflammation.

Upon activation, neutrophils release DNA fibers decorated with antimicrobial proteins, forming neutrophil extracellular traps (NETs). Although NETs are bactericidal and contribute to innate host defense, excessive NET formation has been linked to the pathogenesis of autoinflammatory diseases. However, the mechanisms regulating NET formation, particularly during chronic inflammation, are poorly understood.

Fibrin mimics neutrophil extracellular traps in SEM.

Neutrophil extracellular traps (NETs) are extracellular web-like structures produced by activated polymorphonuclear neutrophils. NETs kill bacteria extracellularly, but their role in human pathology remains largely unclear. One possible way of studying NETs is through the SEM approach.

Neutrophil fate in gingival crevicular fluid.

The fate of the neutrophils within the inflammatory exudate in the periodontal crevice and their possible participation in the formation of neutrophil extracellular traps (NETs) are of clinical interest. However, the cytological analysis of clinical samples of inflammatory exudate is restricted by the obtainable quantities, which do not enable employing the routine approaches. Clinical examinations, ACLAR strip sampling, scanning electron microscopy, and confocal laser scanning microscopy were employed to analyze purulent crevicular exudate and gingival crevicular fluid in periodontitis.

A cover of glass: first report of biomineralized silicon in a ciliate, Maryna umbrellata (Ciliophora: Colpodea).

Using hydrofluoric acid, scanning electron microscope-assisted X-ray microanalysis, and energy-filtered transmission electron microscopy, we present the first definite proof of biomineralized silicon [(SiO(2))](n) in a ciliophoran protist, Maryna umbrellata, a common inhabitant of ephemeral pools. In the trophic specimen, the amorphic silicon (glass) granules are accumulated in the anterior half of the body. When entering the dormant stage, most glass granules are excreted to form the surface cover of the globular resting cyst.

Correlations between AFM and SEM imaging of acid-etched tooth enamel.

Enamel bond strength is an important factor in restorative dentistry and crucially depends on the enamel roughness. To increase roughness, different etching procedures are employed and profilometric estimations, with probe profilometers, including atomic force microscopy (AFM), have been made. However, no correlation between roughness and bond strength has been found.

Visualization of neutrophil extracellular traps in TEM.

Neutrophil extracellular traps (NETs) have recently been described as an important innate defence mechanism in inflammation. However, routine electron microscopic staining techniques faintly stain NETs and are therefore insufficient for enabling a distinction between these and the host cell debris as well as proteins regularly present at the site of inflammation. In order to test suitable electron microscopic staining techniques, NETs induced ex vivo via phorbol myristate were absorbed on formvar.

Restorative therapy of primary teeth severely affected by amelogenesis imperfecta.

Objective: Primary teeth severely affected by amelogenesis imperfecta (AI) often show an extensive loss of enamel. Such defects are difficult to restore with resin composites, since neither the correct anatomic form nor the marginal fit can be guaranteed.

Methods And Materials: After clinical and scanning electron microscopic examinations were performed on replica models of 5 patients with primary teeth affected by AI, impressions were made without previous preparation by rotary instruments.

Surface morphology of pocket epithelium.

The pocket epithelium in periodontitis differs from the clinically healthy epithelium in its increase in sulcular depth. However, closer surface morphological distinctions have not been described. To study the surface characteristics of pocket gingiva, the authors analyzed pocket and sulcular epithelium biopsies by scanning and transmission electron microscopy using cytochemical staining for visualization of bacterial adhesion.

Cytochemical differences in bacterial glycocalyx.

To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S.

Supramolecular pellicle precursors.

Saliva contacting with solid surfaces in the oral cavity forms a coat termed the pellicle. However, its formation is not fully understood. Although indications for the existence of supramolecular pellicle precursors have been reported, the possible relationship between them and pellicle formation is unclear.

Glycocalyx morphology of Candida albicans.

In this study, we examine new cytochemical aspects of the fimbria-mediated adhesion of the oral facultative pathogen Candida albicans. A wild-type strain of the yeast was grown with and without sucrose supplementation for 8 days. Osmium tetroxide, uranyl acetate (UA), ruthenium red (RR), and cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs) and tannic acid-metal salt technique (TAMST) were applied to specimens separately or in combination for transmission electron microscopy (TEM) examination.

Candida-induced stomatopyrosis and its relation to diabetes mellitus.

Background: Glycaemic disorders and oral candidosis can be accompanied by burning mouth sensations. However, no clear relation between all three disorders is known.

Methods: Seventy-two native Upper-Austrians with burning mouth sensations were examined and smears for Candida estimation were taken from the spots where the sensations were felt.

Bacterial adhesion to sulcular epithelium in periodontitis.

The purpose of this study was to investigate, by electron microscopy, the type of bacterial attachment to the sulcular epithelium in periodontitis. Gingiva biopsies were observed in a transmission electron microscope using cytochemical staining with ruthenium red for glycocalyx visualisation. In addition, subgingival plaque samples and biopsies from the sulcular epithelium in periodontitis from the patients were estimated microbiologically.