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Silver is increasingly being used in garments to exploit its antibacterial properties. Information on the presence of silver nanoparticles (AgNPs) in garments and their in vivo penetration across healthy and impaired skin from use is limited. We investigated the presence of AgNPs in a silver containing garment and in the stratum corneum (SC) of healthy subjects (CTRLs) and individuals with atopic dermatitis (AD). Seven CTRLs and seven AD patients wore a silver sleeve (13% Ag w/w) 8 h/day for five days on a forearm and a placebo sleeve on the other forearm. After five days, the layers of the SC were collected by adhesive tapes. The silver particles in the garment and SC were characterized by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and atomic force microscopy (AFM). AFM and SEM revealed the presence of sub-micrometre particles having a broad range of sizes (30-500 nm) on the surface of the garment that were identified as silver. On the SC tapes collected from different depths, aggregates with a wide range of sizes (150 nm-2 μm) and morphologies were found. Most aggregates contained primarily silver, although some also contained chlorine and sulfur. There was no clear difference in the number or size of the aggregates observed in SC between healthy and AD subjects. After use, AgNPs and their aggregates were present in the SC at different depths of both healthy subjects and AD patients. Their micrometre size suggests that aggregation likely occurred in the SC.

Background: Loss-of-function (LOF) mutations in the filaggrin gene (FLG) are a well-replicated risk factor for atopic dermatitis (AD) and are known to cause an epidermal barrier defect. The nature of this barrier defect is not fully understood. Patients with AD with FLG LOF mutations are known to have more persistent disease, more severe disease, and greater risk of food allergies and eczema herpeticum. Abnormalities in corneocyte morphology have been observed in patients with AD, including prominent villus-like projections (VP); however, these ultrastructural features have not been systematically studied in patients with AD in relation to FLG genotype and acute and convalescent status., Objective: We sought to quantitatively explore the relationship between FLG genotype, filaggrin breakdown products (natural moisturizing factor [NMF]), and corneocyte morphology in patients with AD., Methods: We studied 15 children at first presentation of AD and after 6 weeks of standard therapy. We applied atomic force microscopy to study corneocyte conformation in patients with AD stratified by FLG status and NMF level. By using a new quantitative methodology, the number of VPs per investigated corneocyte area was assessed and expressed as the Dermal Texture Index score. Corneocytes were also labeled with an anti-corneodesmosin antibody and visualized with scanning electron microscopy., Results: We found a strong correlation between NMF levels and Dermal Texture Index scores in both acute and convalescent states (respective r = -0.80 and -0.75, P < .001 and P = .002). Most, but not all, VPs showed the presence of corneodesmosin abundantly all over the cell surface in homozygous/compound heterozygous FLG patients and, to a lesser extent, in heterozygous and wild-type patients., Conclusions: NMF levels are highly correlated with corneocyte morphology in patients with AD. These corneocyte conformational changes shed further insight into the filaggrin-deficient phenotype and help explain the barrier defect in patients with AD with FLG LOF mutations., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

A demanding task of medicine is to understand and control the immune system. Central players in the cellular immune response are the leukocytes that leave the blood stream for host defense. Endothelial cells limit the emigration rate of leukocytes. Being located between blood and tissues, they permit or deny the passage. The exact mechanism of this process called diapedesis is not solved yet. Leukocytes can principally traverse either between cells (paracellularly) or directly through an individual endothelial cell (transcellularly). The transcellular way has recently gained experimental support, but it is not clear how the endothelial cytoskeleton manages to open and close a transmigratory channel. Atomic force microscopy was used to investigate the endothelial cytoskeleton. In order to directly access the leukocyte-endothelial interaction site, we applied a special protocol ("nanosurgery"). As a result, the endothelial cell turned out to become softer in a confined region strictly underneath the leukocyte. Fluorescence microscopy confirmed a depolymerization of the f-actin strands at the invasion site. Leukocytes dramatically rearrange the endothelial cytoskeleton to form transmigratory channels.

To invade a tissue, leukocytes have to overcome the endothelial barrier. Prior to trans-endothelial migration, leukocytes move laterally on the endothelial surface-searching for an emigration site. It is still unclear, how the actual diapedesis step is initiated and whether the endothelium has a decisive role. Here, video-microscopy was employed to investigate, whether lateral migration of leukocytes is correlated to their diapedesis rate. To address the contribution of each cell type, selective stimulation of either leukocytes or endothelial cells with TNFα was performed. Stimulation of endothelial cells alone was sufficient for maximal effects, thereby underlining their decisive role for leukocyte diapedesis. Concomitant to the TNFα-enhanced diapedesis rate, leukocyte adhesion was intensified and, unexpectedly, the lateral leukocyte migration was accelerated., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Inflammation and cellular fibrosis often imply an involvement of the cytokine TGF-beta1. TGF-beta1 induces epithelial-to-mesenchymal transdifferentiation (EMT), a term describing the loss of epithelium-specific function. Indicative for this process are an elongated cell shape parallel to stress fibre formation. Many signalling pathways of TGF-beta1 have been discovered, but mechanical aspects have not yet been investigated. In this study, atomic force microscopy (AFM) was used to analyse surface topography and mechanical properties of EMT in proximal kidney tubule epithelium (NRK52E). Elongated cells, an increase of stress fibre formation and a loss of microvillus compatible structures were observed as characteristic signs of EMT. Furthermore, AFM could identify an increase in stiffness by 71% after six days of stimulation with TGF-beta1. As a novel topographical phenomenon, nodular protrusions emerged at the cell-cell junctions. They occurred preferentially at sites where stress fibres cross the border. Since these nodular protrusions were sensitive to inhibitors of force generation, they can indicate intracellular tension. The results demonstrate a manifest impact of elevated tension on the cellular topography.

The endothelium has an important role in controlling the extravasation of leukocytes from blood to tissues. Endothelial permeability for leukocytes is influenced by transmembrane proteins that control inter-endothelial adhesion, as well as steps of the leukocyte transmigration process. In a cascade consisting of leukocyte rolling, adhesion, firm adhesion, and diapedesis, a new step was recently introduced, the formation of a docking structure or "transmigratory cup." Both terms describe a structure formed by endothelial pseudopods embracing the leukocyte. It has been found associated with both para- and transcellular diapedesis. The aim of this study was to characterize the leukocyte-endothelial contact area in terms of morphology and cell mechanics to investigate how the endothelial cytoskeleton reorganizes to engulf the leukocyte. We used atomic force microscopy (AFM) to selectively remove the leukocyte and then analyze the underlying cell at this specific spot. Firmly attached leukocytes could be removed by AFM nanomanipulation. In few cases, this exposed 8-12 microm wide and 1 microm deep footprints, representing the cup-like docking structure. Some of them were located near endothelial cell junctions. The interaction area did not exhibit significant alterations neither morphologically nor mechanically as compared to the surrounding cell surface. In conclusion, the endothelial invagination is formed without a net depolymerization of f-actin, as endothelial softening at the site of adhesion does not seem to be involved. Moreover, there were no cases of phagocytotic engulfment, but instead the formation of a transmigratory channel could be observed.

The prenatal diagnosis of pulmonary sequestration can usually be made by the third trimester of pregnancy, from the combination of an intrathoracic mass and indirect signs such as cardiac deviation, fetal hydrops, pleural effusion and polyhydramnios. We describe four cases in which pulmonary hyperechogenicity was detected before 26 weeks' gestation. In three cases the hyperechogenic mass was isolated. In all cases it had mostly regressed during the pregnancy. A review of the cases of isolated pulmonary sequestration that have been diagnosed during the antenatal period is presented. Antenatal evolution was found to be unpredictable regardless of the type or severity of the case at the first diagnosis. We propose a classification to define more clearly the optimal management of pulmonary sequestration.