The high level of trust in restrictive prescribing as well as the awareness of antibiotic resistance expressed by the Swedish public should be recognized by health professionals and utilized in future campaigns.

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SummaryTight junctions seal the paracellular cleft of epithelia and endothelia, form vital barriers between tissue compartments and consist of tight-junction-associated marvel proteins (TAMPs) and claudins. The function of TAMPs and the interaction with claudins are not understood. We therefore investigated the binding between the TAMPs occludin, tricellulin, and marvelD3 and their interaction with claudins in living tight-junction-free human embryonic kidney-293 cells. In contrast to claudins and occludin, tricellulin and marvelD3 showed no enrichment at cell-cell contacts indicating lack of homophilic trans-interaction between two opposing cell membranes. However, occludin, marvelD3 and tricellulin exhibited homophilic cis-interactions, along one plasma membrane, as measured by fluorescence resonance energy transfer. MarvelD3 also cis-interacted with occludin and tricellulin heterophilically. Classic claudins, such as claudin-1 to -5 may show cis-oligomerization with TAMPs, whereas the non-classic claudin-11 did not. Claudin-1 and -5 improved enrichment of occludin and tricellulin at cell-cell contacts. The low mobile claudin-1 reduced the membrane mobility of the highly mobile occludin and tricellulin, as studied by fluorescence recovery after photobleaching. Co-transfection of claudin-1 with TAMPs led to changes of the tight junction strand network of this claudin to a more physiological morphology, depicted by freezefracture electron microscopy. The results demonstrate multilateral interactions between the tight junction proteins, in which claudins determine the function of TAMPs and vice versa, and provide deeper insights into the tight junction assembly.

Bioprinting is a new technology, which arranges cells with high spatial resolution, but its potential to create models for viral infection studies has not yet been fully realized. The present study describes the optimization of a bioink composition for extrusion printing. The bioinks were biophysically characterized by rheological and electron micrographic measurements. Hydrogels consisting of alginate, gelatin and Matrigel were used to provide a scaffold for a 3D arrangement of human alveolar A549 cells. A blend containing 20% Matrigel provided the optimal conditions for spatial distribution and viability of the printed cells. Infection of the 3D model with a seasonal influenza A strain resulted in widespread distribution of the virus and a clustered infection pattern that is also observed in the natural lung but not in two-dimensional (2D) cell culture, which demonstrates the advantage of 3D printed constructs over conventional culture conditions. The bioink supported viral replication and proinflammatory interferon release of the infected cells. We consider our strategy to be paradigmatic for the generation of humanized 3D tissue models by bioprinting to study infections and develop new antiviral strategies.

Bioprinting is a novel technology that may help to overcome limitations associated with two-dimensional (2D) cell cultures and animal experiments, as it allows the production of three-dimensional (3D) tissue models composed of human cells. The present study describes the optimization of a bioink composed of alginate, gelatin and human extracellular matrix (hECM) to print human HepaRG liver cells with a pneumatic extrusion printer. The resulting tissue model was tested for its suitability for the study of transduction by an adeno-associated virus (AAV) vector and infection with human adenovirus 5 (hAdV5). We found supplementation of the basic alginate/gelatin bioink with 0.5 and 1 mg/mL hECM provides desirable properties for the printing process, the stability of the printed constructs, and the viability and metabolic functions of the printed HepaRG cells. The tissue models were efficiently transduced by AAV vectors of serotype 6, which successfully silenced an endogenous target (cyclophilin B) by means of RNA interference. Furthermore, the printed 3D model supported efficient adenoviral replication making it suitable to study virus biology and develop new antiviral compounds. We consider the approach described here paradigmatic for the development of 3D tissue models for studies including viral vectors and infectious viruses.

Apoptosis of neutrophils is a key mechanism to control the intensity of the acute inflammatory response. Previously, the cytokine TNF‐α was reported by some investigators to have pro‐apoptotic and by others to have antiapoptotic effects on neutrophils. The aim of this study was to explain these contradictory results. We found that TNF‐α at low concentrations strongly decreased apoptosis of neutrophils. However, at higher concentrations, TNF‐α lost its protective effects, and also reversed the anti‐apoptotic effects of IFN‐γ and GM‐CSF. In fact, the combination of high concentrations of TNF‐α with either IFN‐γ or GM‐CSF caused even stronger apoptosis than that seen in the presence of TNF‐α alone. This ‘pro‐apoptotic’ effect of TNF‐α was blocked by anti‐CD11b and was absent in neutrophils from patients with Leukocyte Adhesion Deficiency (LAD), which lack expression of β2 integrins, and in neutrophils from patients with Chronic Granulomatous Disease (CGD), which cannot produce toxic oxygen metabolites. Under these circumstances, we found that TNF‐α retained its anti‐apoptotic effects, even at high concentrations. In conclusion, the protective effects against apoptosis of IFN‐γ, GM‐CSF and TNF‐α itself are overruled when the concentration of TNF‐α is high enough to produce a respiratory burst. This process of reactive oxygen radical formation depends on neutrophil adhesion via the β2 integrin CD11b/CD18 and on an intact NADPH oxidase enzyme. These dual, concentration‐dependent effects of TNF‐α provide an explanation for previous controversial reports and support a dominant role for TNF‐α in neutrophil apoptosis.

Objective To explore and describe perceptions of antibiotic prescribing among Swedish hospital physicians, with special reference to whether the perceptions included awareness of antibiotic resistance (AR). Design A phenomenographic approach was used and data were collected in face-to-face interviews. Setting Hospitals in seven different counties in central Sweden.Participants A strategic sample of 20 hospital physicians specialising in internal medicine, surgery or urology.Main outcome The variation of perceptions of antibiotic prescribing.Results Five qualitative different perceptions were found. AR was considered in two of the perceptions. Reasons for not considering AR included a dominating focus on the care of the patient combined with lack of focus on restrictive antibiotic use, or uncertainty about how to manage infectious diseases or the pressure from the healthcare organisation. Parallels between the five perceptions and the stages in the transtheoretical model of health behaviour change were seen. Conclusions In three of the perceptions, AR was not considered when antibiotics were prescribed. Physicians who primarily express these three perceptions do not seem to be prepared to change to restrictive prescribing. Our findings can be useful in designing activities that encourage AR prevention. Organisational changes are also needed.

IntroductionQuantum dots (QDs) are crystalline semiconductors approximately 1-20 nm in diameter. QD nanocrystals composed of CdSe cores and ZnS shells have received attention due to their unique electronic and optoelectronic properties at nanoscale levels and their widespread applications (1-8). Because of their unique characteristics, QDs are used at increasing rates for a wide variety of industrial and consumer-based applications, including biomedical imaging agents, inks, and solar panels (5,9-11). QDs may also pose risks to human health, where unintended exposure to nanomaterials may occur at the workplace or during end product use via inhalation, dermal absorption, or gastrointestinal tract absorption (12). Dermal exposures to QD particles have shown toxicities due to heavy metal exposure and/or the production of reactive oxygen intermediates (ROIs) (13)(14)(15) .Due to the growing number of potential uses that are offered by QD materials, consumer handling and manufacturer exposure to QDs is likely to increase. Nanoscale materials are thought to impose increased adverse effects on organisms than microscale materials because of their finer sizes and corresponding larger specific surface areas per unit mass (16)(17)(18). However, it is largely unknown which specific pathways or subcellular mechanisms of action are triggered as a result of QD exposure. Many investigators have shown that QDs can be internalized into cells and others have speculated the route of entry for particular , but what are the mechanisms of injury and key participants on the molecular level in the cell and how do those processes develop? We hypothesized that immune mediators of inflammation may be initiated in the exposed cell layers.In an attempt to fill this gap, human epithelial keratinocytes (HEK), found in the epidermis, and human dermal fibroblasts (HDF), located in the dermis, were utilized to query the © 2011 Elsevier Ltd. All rights reserved. § Corresponding author: Christie Sayes (csayes@cvm.tamu.edu). Secondary corresponding author: Michael Criscitiello (mcriscitiello@cvm.tamu.edu), AAR: aromoser@cvm.tamu.edu, PLC: pchen@cvm.tamu.edu, JMB: mberg@cvm.tamu.edu, CS: cseabury@cvm.tamu.edu, II: iivanov@cvm.tamu.edu, MFC: mcriscitiello@cvm.tamu.edu, CMS: csayes@cvm.tamu.edu . Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptMol Immunol. Author manuscript; available in PMC 2012 July 1. The human dermal fibroblast cell line was of interest partially due to its proximity to the vascular system and its importance in maintaining the structural framework of the ti...