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Extracellular matrix (ECM) is a dynamic network of proteins, proteoglycans and glycosaminoglycans, providing structure to the tissue and biochemical and biomechanical instructions to the resident cells. In fibrosis, the composition and the organization of the ECM are altered, and these changes influence cellular behaviour. Biochemical (i. e. protein composition) and biomechanical changes in ECM take place simultaneously in vivo. Investigating these changes individually in vitro to examine their (patho)physiological effects has been difficult. In this study, we generated an in vitro model to reflect the altered mechanics of a fibrotic microenvironment through applying fibre crosslinking via ruthenium/sodium persulfate crosslinking on native lung ECM-derived hydrogels. Crosslinking of the hydrogels without changing the biochemical composition of the ECM resulted in increased stiffness and decreased viscoelastic stress relaxation. The altered stress relaxation behaviour was explained using a generalized Maxwell model. Fibre analysis of the hydrogels showed that crosslinked hydrogels had a higher percentage of matrix with a high density and a shorter average fibre length. Fibroblasts seeded on ruthenium-crosslinked lung ECM-derived hydrogels showed myofibroblastic differentiation with a loss of spindle-like morphology together with greater α-smooth muscle actin (α-SMA) expression, increased nuclear area and circularity without any decrease in the viability, compared with the fibroblasts seeded on the native lung-derived ECM hydrogels. In summary, ruthenium crosslinking of native ECM-derived hydrogels provides an exciting opportunity to alter the biomechanical properties of the ECM-derived hydrogels while maintaining the protein composition of the ECM to study the influence of mechanics during fibrotic lung diseases. STATEMENT OF SIGNIFICANCE: Fibrotic lung disease is characterized by changes in composition and excessive deposition of extracellular matrix (ECM). ECM fibre structure also changes due to crosslinking, which results in mechanical changes. Separating the changes in composition and mechanical properties has been difficult to date. In this study, we developed an in vitro model that allows alteration of the mechanical changes alone by applying fibre crosslinking in native lung ECM-derived hydrogels. Characterisations of the crosslinked hydrogels indicated the model mimicked mechanical properties of fibrotic lung tissue and reflected altered fibre organisation. This ECM-based fibrosis model provides a method to preserve the native protein composition while altering the mechanical properties providing an important tool not only for lung but also other organ fibrosis.

Objectives: Life's Simple 7 (LS7) metrics provide insight into improving cardiovascular health (CVH) and help reduce mortality risks. Edentulous older adults have a higher mortality risk than dentulous ones, probably due to worse oral function. It is reported that wearing dentures will decrease the mortality risk factor by improving oral function. This prospective study aimed to investigate if denture wearing could modify the association between CVH profile and mortality risk among edentulous elderly.Methods: From the Third National Health and Nutrition Examination Survey (NHANES III), 1,735 edentulous older adults (mean age 69.4 years old) with CVH profiles and data on denture wearing status were selected for this study. CVH profiles according to LS7 metrics were classified into poor, intermediate, or ideal. Denture wearers were defined as those wearing complete dentures in both arches all the time or only when awake. Multivariable Cox proportional-hazards regression was conducted to estimate the association of CVH profiles with all-cause and cardiovascular mortality. Stratified analyses and the testing of interaction terms were used to evaluate the difference between the association in edentulous patients with and without dentures.Results: A total of 1,420 (81.8%) older adults died during the 27-year follow-up, with 478 (27.6%) cases attributable to heart disease. After controlling for potential confounders, edentulous patients with an ideal CVH (LS7 = 10–14) had a lower mortality risk than those with poor CVH (LS7 = 0–4). Furthermore, we observed an effect modification by denture use (P interaction = 0.046), with the role of ideal CVH in mitigating mortality among the denture wearers (Hazard Ratio = 0.440 [0.329–0.588]), while no significant association among those without dentures. Similar results were achieved for cardiovascular mortality, but there was no effect modification of denture use (P interaction = 0.352).Conclusion: In this study, a favorable cardiovascular health profile presents a protective effect on all-cause mortality only among edentulous patients wearing dentures instead of non-wearer. Clinical Significance: Denture usage could improve oral function (e.g., chewing, smiling, speaking, etc.) and promote general health. Effect modification found in this study indicates having ideal CVH alone cannot substantially reduce mortality risk among edentulous patients. Therefore, health care professionals should keep an eye on the elderly not wearing dentures as they are probably more at risk for adverse health outcomes. It remains unclear if denture wearing has a causal relation with lower mortality risks, and further research is needed.

Motor adaptation is a form of learning to re-establish desired movements in novel situations. To probe motor adaptation, one can replicate such conditions experimentally by imposing a sustained perturbation during movement. Exposure to such perturbations initially causes an abrupt change in relevant performance variables, followed by a gradual return to baseline behaviour. The resulting time series exhibit persistent properties related to structural changes in underlying motor control and transitory properties related to trial-to-trial variations. The global trend, signifying the structural change, is often assessed by averaging the time series in predefined bins or nonlinear model fitting. However, these methods to study motor adaptation require a priori decisions to produce accurate fits. Here, we test a data-driven approach called Singular Spectrum Analysis (SSA) to assess the global trend. In SSA, we first decompose the adaptation time series into components that represent either a global trend or additional variations, and secondly, select the component(s) corresponding to the global trend using spectral analysis. In this paper, we will use simulated data to compare the reconstruction performance of SSA with often applied filter and fitting methods in motor adaptation studies and apply SSA to real data obtained during split-belt adaptation. In the simulations, we show that SSA reconstructed the fast-initial component and entire global trends more accurately than the filtering and fitting methods. In addition, we show that SSA also successfully reconstructed global trends from real data. Therefore, the SSA might be useful in motor learning studies to decompose and assess adaptation time series.

The accuracy of a phenotypic scheme to recognize periodontal Prevotella intermedia/nigrescens group clinical isolates on primary isolation culture plates was assessed with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS). A total of 84 fresh subgingival isolates from 23 chronic periodontitis patients were presumptively recognized on anaerobically-incubated enriched Brucella blood agar primary isolation plates as P. intermedia/nigrescens based on their dark-pigmented colony morphology, brick-red autofluorescence under long-wave ultraviolet light, and a negative fluorescence test for lactose production. The presumptive P. intermedia/nigrescens clinical isolates were subjected to MALDI-TOF MS analysis using Bruker MALDI Biotyper analytic software containing mass spectra for P. intermedia and Prevotella nigrescens in its reference library of bacterial protein profiles. Using a ≥1.7 log score agreement threshold, 60 (71.4%) of the presumptive P. intermedia/nigrescens clinical isolates were confirmed as either P. intermedia (25 isolates) or P. nigrescens (35 isolates). All isolates with a

Hydrophilic lubricious coatings on the catheter surface reduce friction against the blood vessel wall but give rise to iatrogenic complication of particle release, embolization and thin blood vessel blockage leading to pulmonary infarction and stroke. Layer by layer deposited PLL (poly- l -lysine) and HA (hyaluronan) coating fills the urgent need of thinner lubricious coating which does not lead to release of large particles. The 8 layered PLL-HA coating was able to maintain low friction and prevent wear of endothelial glycocalyx layer (EGL). Wear and loss of EGL is a gradual process and occurred while sliding the blood vessel against bare catheter surface or 4 layered coating accompanied by epithelial cells damage and decrease in the number of nucleuses.

Objective. The aim of this study was to investigate the influence of the luting agent on the application of laminate veneers (LVs) in an accelerated fatigue and load-to-failure test after thermo-cyclic aging.Methods. Sound maxillary central incisors (N = 40) were randomly divided into four groups to receive LVs (Li2Si2O5) that were adhesively bonded: Group CEMF: Adhesive cement (Variolink Esthetic LC), fatigue test; Group CEMLF: Adhesive cement, load-to-failure test; Group COMF: Resin composite (Enamel HFO), fatigue test; Group COMLF: Resin composite, load-to-failure test. The specimens were thermo-mechanically aged (1.2 x 10(6) cycles at 1.7 Hz/50 N, 8000 cycles 5-55 degrees C) and then subjected to either accelerated fatigue (5 Hz, 25 N increasing after each 500 cycles) or load to failure (1 mm/min). Failure types were classified and data analyzed using chi-square, Kaplan Meier survival, Log Rank (Mantel-Cox) and independent-samples t-test.Results. After thermo-mechanical aging, fracture resistance (p Significance. The delivery of laminate veneers using a direct restorative composite rather than a resin cement resulted in significantly less chipping and fractures, higher fracture strength in both accelerated fatigue and load-to-failure.

Four clinical isolates of gram-positive strict anaerobic cocci were isolated from four different human mixed anaerobic infections. The taxonomical status of the four strains could not be established using standard identification techniques. The biochemical features of the strains were established and their taxonomic position was determined using 16S rRNA sequencing. The four strains form a homogeneous phenotypical and genotypical cluster. A new Anaerococcus species is proposed for these isolates: Anaerococcus degenerii sp. nov. The type strain is UMCG-104(T) = DSM29674(T) (accession number AM176528). (C) 2015 Elsevier Ltd. All rights reserved.

Surfaces with cell adhesiveness modulated at micro length scales can exploit differences between tissue/bacterial cell size, membrane/wall plasticity, and adhesion mechanisms to differentially control tissue-cell/material and bacteria/material interactions. This study explores the short-term interactions of Staphylococcus aureus and osteoblast-like cells with surfaces consisting of cell-adhesive circular patches (1-5 mu m diameter) separated by non-adhesive electron-beam patterned poly(ethylene glycol) hydrogel thin films at inter-patch distances of 0.5-10 mu m. Osteoblast-like U2OS cells both bind to and spread on the modulated surfaces, in some cases when the cell-adhesive area comprises only 9% of the total surface and in several cases at least as well as on the continuously adhesive control surfaces. In contrast, S. aureus adhesion rates are 7-20 times less on the modulated surfaces than on the control surfaces. Furthermore, the proliferation of those bacteria that do adhere is inhibited by the lateral confinement imposed by the non-adhesive boundaries surrounding each patch. These findings suggest a new approach to create biomaterial surfaces that may promote healing while simultaneously reducing the probability of infection. (C) 2014 Elsevier Ltd. All rights reserved.

Objectives The aim of this randomized controlled study was to cephalometrically assess possible changes in craniofacial morphology associated with long term use of an adjustable oral appliance compared with continuous positive airway pressure (CPAP) in patients with the obstructive sleep apnea/hypopnea syndrome (OSAHS) In addition we wanted to study the relationship between these possible changes and the degree of mandibular protrusion associated with oral appliance therapyMethods Fifty one patients were randomized to oral appliance therapy and 52 patients to CPAP therapy At baseline and after follow up (2 3 +/- 0 2 years), a lateral cephalogram of all patients was made in maximum intercuspation to determine relevant cephalometric variables Both baseline and follow up cephalograms were traced digitally whereupon cephalometric variables were compared Changes in craniofacial morphology between the oral appliance and CPAP group were evaluated with a linear regression analysisResults Compared with CPAP long term use of an oral appliance resulted in small but significant (dental) changes Overbite and overjet decreased 1 0 (+/- 1 5) mm and 1 7 (+/- 1 6) mm respectively Furthermore we found a retroclination (-2 0 (+/- 2 8)degrees) of the upper incisors and a proclination (3 7 (+/- 5 4)degrees) of the lower incisors Moreover the lower and total anterior facial height increased significantly 0 8 (+/- 1 5) mm and 0 9 (+/- 1 4) mm respectively No changes in skeletal variables were found Linear regression analysis revealed that the decrease in overbite was associated with the mean mandibular protrusion during follow up (B = -0 029 SE = 0 014 p Conclusions Oral appliance therapy should be considered as a life long treatment and there is a risk of craniofacial changes to occur Therefore patients treated with an oral appliance need a thorough follow up by a dentist or dental specialist experienced in the field of dental sleep medicine Crown Copyright (C) 2010 Published by Elsevier Ltd All rights reserved

Biomaterial-associated infections constitute a major clinical problem. Unfortunately, microorganisms are frequently introduced onto an implant surface during surgery and start the race for the surface before tissue integration can occur. So far, no method has been forwarded to study biofilm formation and tissue integration simultaneously. The aim of this study is to describe an in vitro method to investigate this "race for the surface". First, a suitable growth medium was prepared that allowed both bacterial and tissue growth in a parallel plate flow chamber. Staphylococci were deposited on the glass bottom plate of the flow chamber in different surface densities, after which U2OS osteosarcoma cells were seeded. U2OS cells did not grow in the absence of flow, possibly due to poisoning by bacterial endotoxins, but under flow both staphylococci and U2OS cells grew. The number of adhering cells and area per spread cell were determined after 48 h in relation to the initial number of bacteria present. Both the number and spread area per cell decreased with increasing density of adhering staphylococci. This demonstrates that the outcome of the race for the surface between bacteria and tissue cells is dependent on the number of bacteria present prior to cell seeding. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Pin tract infections of external fixators used in orthopacclic reconstructive bone surgery are serious cornplications that can eventually lead to periostitis and osteomyelitis. In vitro experiments have demonstrated that bacteria adhering to stainless steel in a biotilm mode of growth detach under the influence of small electric currents, while remaining bacteria become less viable upon current application. Therefore, we have investigated whether a 100 mu A electric current can prevent signs of clinical infection around percutaneous pins, implanted in the tibia of goats. Three pins were inserted into the lateral right tibia of nine goats, of which one served for additional frame support. Two pins were infected with a Staphylococcus epidermidis strain of which one pin was subjected to electric current, while the other pin was used as control. Pin sites were examined daily. The wound electrical resistance decreased with worsening of the infection from a dry condition to a purulent stage. After 21 days, animals were sacrificed and the pins taken out. Infection developed in 89% of the control pin sites, whereas only 11 % of the pin sites in the current group showed infection. These results show that infection of percutaneous pin sites of external fixators in reconstructive bone surgery can be prevented by the application of a small DC electric current. (c) 2007 Elsevier Ltd. All rights reserved.

Antibiotic-loaded acrylic bone cement is widely used in total joint replacement to reduce infections. Walking results in cyclic loading, which has been suggested to stimulate antibiotic release. The goal of this study is to compare antibiotic release from cyclically loaded bone cement with the release from unloaded bone cement. Two models of the frontal aspect of a femoral stem were cemented with CMW 1 Radiopaque G, Palacos R-G and Palamed G. Both were immersed in water, and the gentamicin concentration in the water was monitored. One model was cyclically loaded at 5 Hz during immersion achieving physiological stresses in the bone cement mantle. After 10.8 x 10(6) cycles, initial release of gentamicin from Palamed G was increased significantly for loaded over unloaded, but not from CMW 1 Radiopaque G and Palacos R-G. (c) 2004 Elsevier Ltd. All rights reserved.

Biocompatibility of biomaterials relates, amongst others, to the absence of adverse cellular reactions and modulation of cell adhesion and subsequent responses. With respect to tissue-engineering applications, most materials need to evoke cell adhesion and spreading, while potentially displaying differential cell function. Adhesion has frequently been studied in a controlled fashion, using adhesion-supporting and -inhibiting substrata. The aim of this study is to create a panel of related materials with gradually changing surface characteristics in order to sustain similar individual cell adhesion and spreading, yet different cell population behaviour. A series of polystyrene materials was created with increasing oxygen surface incorporation and, concurrently, decreasing water-contact angles. Individual cells adhered and spread on all surfaces whilst showing well-developed focal adhesions and stress fibres. Cell populations demonstrated a decreased growth on surfaces with lower wettability. The biochemical activity of cell populations was not influenced by the surface treatment, but cell proliferation on surfaces increased with increasing oxygen incorporation. Furthermore, surface coverage with assembled fibronectin matrix was higher on the substrata with higher wettability. Finally, the expression of the adhesion-related proteins cadherin-5, focal adhesion kinase and RhoA was increased on surfaces with higher wettability. Further explorations of the cell biological basis of the observed differential behaviour will give more detailed answers on the rules governing cell-material interactions. (C) 2003 Elsevier Ltd. All rights reserved.

The aim of this study is to determine rigid gas permeable (RGP) lens surface properties prior to and after wear that are influential on adhesion of Pseudomonas aeruginosa. After 10 and 50 days of wear and after end-stage use, lenses were collected for determination of physico-chemical surface properties and bacterial adhesion in a parallel plate flow chamber. Water contact angles on unused RGP lenses amounted 47 +/- 13degrees and were affected by wear. In addition, %O at the lens surfaces, as determined by X-ray photoelectron spectroscopy increased after use for 10 and 50 days, but decreased after end-stage wear. The %N hardly increased after wear and, in line, SDS-PAGE did not indicate adsorbed proteins. The surface roughness of the lenses, as measured by atomic force microscopy amounted 9nm after 10 and 50 days of use, but end-stage lenses were significantly rougher (48 +/- 23 nm). Moreover, initial deposition of P. aeruginosa #3 increased with increasing roughness for end-stage lenses. Multiple regression analysis, however, revealed that both physical and chemical surface properties were predictive for initial bacterial deposition to lens surfaces. After 10 days of wear, bacterial deposition was governed by the water contact angle, surface roughness, %O, %N, and %Si, while after 50 days of wear the surface roughness, %N, and %Si were found predictive for bacterial deposition. Initial bacterial deposition to end-stage lenses was solely dependent on the surface roughness. Summarizing, physico-chemical surface properties of RGP lenses change slightly during the first 10-50 days of wear, but end-stage lenses all had increased surface roughness, concurrent with increased bacterial adhesion. (C) 2002 Elsevier Science Ltd. All rights reserved.

Transplantation of encapsulated living cells is a promising approach for the treatment of a wide variety of diseases. Large-scale application of the technique, however, is hampered by insufficient biocompatibility of the capsules. In the present study, we have implemented new as well as previously reported technologies to test biocompatibility issues of immunoisolating microcapsules on the long term (i.e. 2 years) instead of usually reported short time periods. When transplanted empty, the capsules proved to be highly biocompatible not only for short periods (i.e. 1 month) but also on the long term as evidenced by the absence of any significant biological response up to 2 years after implantation in rats. The immunoprotective properties of the capsules were confirmed by prolonged survival of encapsulated islet allografts up to 200 days. The surface of the applied capsule was analyzed and provides new insight in the chemical structure of true biocompatible and immunoprotective capsules applicable for transplantation of encapsulated islets in type I diabetes. (C) 2002 Elsevier Science Ltd. All rights reserved.