Potassium ion channels as a molecular target to reduce virus infection and mortality of honey bee colonies.

Declines in managed honey bee populations are multifactorial but closely associated with reduced virus immunocompetence and thus, mechanisms to enhance immune function are likely to reduce viral infection rates and increase colony viability. However, gaps in knowledge regarding physiological mechanisms or 'druggable' target sites to enhance bee immunocompetence has prevented therapeutics development to reduce virus infection. Our data bridge this knowledge gap by identifying ATP-sensitive inward rectifier potassium (KATP) channels as a pharmacologically tractable target for reducing virus-mediated mortality and viral replication in bees, as well as increasing an aspect of colony-level immunity. Bees infected with Israeli acute paralysis virus and provided KATP channel activators had similar mortality rates as uninfected bees. Furthermore, we show that generation of reactive oxygen species (ROS) and regulation of ROS concentrations through pharmacological activation of KATP channels can stimulate antiviral responses, highlighting a functional framework for physiological regulation of the bee immune system. Next, we tested the influence of pharmacological activation of KATP channels on infection of 6 viruses at the colony level in the field. Data strongly support that KATP channels are a field-relevant target site as colonies treated with pinacidil, a KATP channel activator, had reduced titers of seven bee-relevant viruses by up to 75-fold and reduced them to levels comparable to non-inoculated colonies. Together, these data indicate a functional linkage between KATP channels, ROS, and antiviral defense mechanisms in bees and define a toxicologically relevant pathway that can be used for novel therapeutics development to enhance bee health and colony sustainability in the field.

Universal Langmuir and Fractal Analysis of High-Resolution Adsorption Isotherms of Argon and Nitrogen on Macroporous Silica.

High-resolution isotherms of argon and nitrogen adsorption on macroporous silica have been simulated with universal Langmuir and fractal models. A four-parameter, fractal universal Langmuir equation is a good fit to the data at low pressures. Standard Gibbs energy changes calculated from equilibrium adsorption coefficients show a series of broad peaks that indicate adsorbate structural transformations as a function of pressure and coverage. The Freundlich equation or mean fractal model is also a good fit to isotherms at low pressures. Pressure-varying fractals are accurate fits to the data. Fractal exponents provide information on adsorbate coverage and surface access. Broad peaks in pressure-varying exponents are indicators of adsorbate structure. From adsorptive gas amounts, mean and pressure-varying fractal exponents provide details of adsorbate fractal dimensions and surface roughness. Both Ar and N2 adsorption cause increases in mean surface roughness when compared with pure silica. Surface roughness fluctuations from pressure-dependent adsorptive gas fractal dimensions are associated with adsorbate structure. At one trough, the surface is smooth and is linked to close-packed Ar or N2. For Ar adsorption at 87 K, this structure is a complete monolayer (1.00(4)), while for Ar (77 K), 1.15(4) layers and for N2 (87 K), 2.02(10) layers. The universal Langmuir specific area of the silica is 10.1(4) m2 g-1. Pressure- and coverage-dependent adsorbate structures range from filling defects and holes on the surface to cluster formation to adsorbed Ar or N2 evenly distributed or packed across the surface. The Ar (87 K) isotherm is most sensitive to adsorbate structural transformations.

Acute toxicity of atrazine, alachlor, and chlorpyrifos mixtures to honey bees.

The acute toxicity of chlorpyrifos and chlorpyrifos-oxon (organophosphorothioate insecticides) was examined alone and in combination with atrazine (triazine herbicide) and alachlor (chloroacetanilide herbicide) to honey bees (Apis mellifera). Atrazine and alachlor were observed to not be acutely toxic to bees at doses up to 10 and 4 µg per bee, respectively. However, atrazine significantly increased chlorpyrifos toxicity by 3-fold while reducing chlorpyrifos-oxon toxicity by 1.8-fold. These changes in toxicity are correlated with significant 1.3- and 1.2-fold inhibition of acetylcholinesterase (AChE) activity in bees exposed to chlorpyrifos and chlorpyrifos-oxon, respectively. Atrazine significantly increased cytochrome P450, general esterase, and glutathione S-transferase (GST) activities by 1.5-, 1.2-, and 1.2- fold respectively, in bees compared to untreated individuals. Alachlor increased chlorpyrifos toxicity by 2.5-fold but did not affect the toxicity of chlorpyrifos-oxon. Exposure to alachlor and chlorpyrifos did not affect AChE compared to chlorpyrifos alone. However, exposure to chlorpyrifos-oxon and alachlor significantly increased acetylcholinesterase (AChE) activity by 1.4-fold. GST activity, but not P450 or general esterases, was significantly increased in bees exposed to alachlor. These data provide evidence that triazine and chloroacetanilide herbicide exposure alters detoxification enzyme activity and, in turn, alters the sensitivity of bees to organophosphorothioate insecticides. Importantly, these data can be used to guide future studies aiming to test safety profiles for pollinators and expand regulatory framework required for pesticide registration.

Clinical Performance of CAD/CAM Monolithic Lithium Disilicate Implant-Supported Single Crowns Using Solid or Predrilled Blocks in a Fully Digital Workflow: A Retrospective Cohort Study With Up To 33 Months of Follow Up.

PURPOSE: To assess the clinical performance of CAD/CAM monolithic implant-supported restorations manufactured using a fully digital workflow and two different types of ceramic blocks. MATERIALS AND METHODS: One hundred and one patients received single-unit implant-supported restorations at a University predoctoral clinic. All restorations were designed and fabricated using either a predrilled LS2 block (group P, n = 59) or a conventional solid LS2 block with an occlusal opening drilled manually prior to crystallization (group M, n = 42). The mean follow-up time after restoration delivery was 18.4 ± 4.8 months (range 12 to 33 months). Patients with less than a 12-month follow-up were excluded. Electronic health records were reviewed to identify number and type of complications during the follow-up time. Clinical outcomes were classified as success, survival, and failure of the restoration. Chi-square tests were used to identify differences in success and survival rates between the groups. Nonparametric Mann-Whitney U tests were used to identify differences in the number of major and minor complications as well as the total number of complications that were observed among groups. RESULTS: Overall success and survival rates were 80.2% and 97%, respectively. Seventy one restorations (70.3%) were complication-free. There were no significant differences between the groups with regards to the number of complications or success and survival rates. CONCLUSIONS: Single-unit CAD/CAM monolithic implant-supported restorations that are fabricated in a fully digital workflow present relatively high complication rates and moderate short-term clinical outcomes. Clinical studies with longer follow-up times are needed to evaluate long-term outcomes of these restorations.

Transcriptome-based screening of ion channels and transporters in a migratory chondroprogenitor cell line isolated from late-stage osteoarthritic cartilage.

Chondrogenic progenitor cells (CPCs) may be used as an alternative source of cells with potentially superior chondrogenic potential compared to mesenchymal stem cells (MSCs), and could be exploited for future regenerative therapies targeting articular cartilage in degenerative diseases such as osteoarthritis (OA). In this study, we hypothesised that CPCs derived from OA cartilage may be characterised by a distinct channelome. First, a global transcriptomic analysis using Affymetrix microarrays was performed. We studied the profiles of those ion channels and transporter families that may be relevant to chondroprogenitor cell physiology. Following validation of the microarray data with quantitative reverse transcription-polymerase chain reaction, we examined the role of calcium-dependent potassium channels in CPCs and observed functional large-conductance calcium-activated potassium (BK) channels involved in the maintenance of the chondroprogenitor phenotype. In line with our very recent results, we found that the KCNMA1 gene was upregulated in CPCs and observed currents that could be attributed to the BK channel. The BK channel inhibitor paxilline significantly inhibited proliferation, increased the expression of the osteogenic transcription factor RUNX2, enhanced the migration parameters, and completely abolished spontaneous Ca2+ events in CPCs. Through characterisation of their channelome we demonstrate that CPCs are a distinct cell population but are highly similar to MSCs in many respects. This study adds key mechanistic data to the in-depth characterisation of CPCs and their phenotype in the context of cartilage regeneration.

Pressure-varying Langmuir parameters and stepped nitrogen adsorption on alumina and silica.

Insights into surface structures and thermodynamics are provided for nitrogen adsorption on two nonporous alumina adsorbents and two macroporous silica adsorbents by modelling high-resolution data using the simple Langmuir isotherm equation combined with pressure-varying flexible least squares. The fitted parameters, maximum adsorption capacity and standard Gibbs energy change for each adsorbent show multiple steps that are assumed to be indicative of transitions to different complete monolayer and multilayer structures. Pressure-varying N2 cross-sectional areas for three of the adsorbents are calculated by assuming that one of the steps is the Brunauer-Emmett-Teller monolayer with molecular area 16.2 Å2. The silica with added octyldimethylsilyl groups has pressure-varying parameter profiles that differ from the other adsorbents and here the N2 cross-sectional area is assumed to be 21.3 Å2 to ensure consistency with the literature surface area. Seven monolayers and multilayers are identified across the four adsorbents, and corresponding molecular areas compare favourably with reported values. At low pressures, adsorption occurs at the strongest sites, and is localised and dependent on surface heterogeneity and topography. Up to five complete, two-dimensional lattice structures are apparent in the mid-pressure ranges. At high pressures, multilayers and liquefaction points are observed and are independent of surface composition and heterogeneity.

Effect of the Z- and Macro-R-Group on the Thermal Desulfurization of Polymers Synthesized with Acid/Base "Switchable" Dithiocarbamate RAFT Agents.

Thermolysis is examined as a method for complete desulfurization of reversible addition-fragmentation chain transfer (RAFT)-synthesized polymers prepared with acid/base "switchable" N-methyl-N-pyridyldithiocarbamates [RS2 CZ or RS2 CZH+ ]. Macro-RAFT agents from more activated monomers (MAMs) (i.e., styrene (St), N-isopropylacrylamide (NIPAm), and methyl methacrylate (MMA)) with RS2 CZH+ and less activated monomers (LAMs) (i.e., vinyl acetate (VAc) and N-vinylpyrolidone (NVP)) with RS2 CZ are prepared by RAFT polymerization and analyzed by thermogravimetric analysis. In all cases, a mass loss consistent with loss of the end group (ZCS2 H) is observed at temperatures lower than, and largely discrete from, that required for further degradation of the polymer. The temperatures for end group loss and the new end groups formed are strongly dependent on the identity of the R(P)n and the state of the pyridyl Z group; increasing in the series poly(MMA) < poly(St) ∼ poly(NIPAm) << poly(VAc) ∼ poly(NVP) for S2 CZ and poly(MMA) < poly(St) ∼ poly(NIPAm) for S2 CZH+ . Clean end group removal is possible for poly(St) and poly(NVP). For poly(NIPAm), the thiocarbonyl chain end is removed, but the end group identity is less certain. For poly(MMA) and poly(VAc), some degradation of the polymer accompanies end group loss under the conditions used and further refinement of the process is required.

The effect of experience, simulator-training and biometric feedback on manual ventilation technique.

OBJECTIVE: To determine the frequency of provision and main providers (veterinary surgeons, nurses or trainees) of manual ventilation in UK veterinary practices. Furthermore, to determine the variation in peak inspiratory (inflation) pressure (PIP), applied to a lung model during manual ventilation, by three different groups of operators (inexperienced, experienced and specialist), before and after training. STUDY DESIGN: Questionnaire survey, lung model simulator development and prospective testing. METHODS: Postal questionnaires were sent to 100 randomly selected veterinary practices. The lung model simulator was manually ventilated in a staged process over 3 weeks, with and without real-time biometric feedback (PIP display), by three groups of volunteer operators: inexperienced, experienced and specialist. RESULTS: The questionnaires determined that veterinary nurses were responsible for providing the majority of manual ventilation in veterinary practices, mainly drawing on theoretical knowledge rather than any specific training. Thoracic surgery and apnoea were the main reasons for provision of manual ventilation. Specialists performed well when manually ventilating the lung model, regardless of feedback training. Both inexperienced and experienced operators showed significant improvement in technique when using the feedback training tool: variation in PIP decreased significantly until operators provided manual ventilation at PIPs within the defined optimum range. Preferences for different forms of feedback (graphical, numerical or scale display), revealed that the operators' choice was not always the method which gave least variation in PIP. CONCLUSIONS AND CLINICAL RELEVANCE: This study highlighted a need for training in manual ventilation at an early stage in veterinary and veterinary nursing careers and demonstrated how feedback is important in the process of experiential learning. A manometer device which can provide immediate feedback during training, or indeed in a real clinical setting, should improve patient safety.

Evaluation of the technological and sensory properties of durum wheat spaghetti enriched with different dietary fibres.

The incorporation of fibres, whether insoluble or soluble, in durum wheat pasta negatively impacts desirable end-use properties, especially if incorporated in significant amounts. Fibres can disrupt the starch-protein matrix of the dough during pasta preparation and can also often swell more readily with water than starch, competing with the starch for water during dough development. Similar degrees of substitution with different fibres gave markedly different impacts on firmness, stickiness, cooking loss and sensory attributes, suggesting that results obtained for one fibre cannot readily be generalized to other fibres. The in vitro starch digestibility of the pastas was significantly reduced when resistant starch, ß-glucan-enriched flour, carboxymethyl cellulose or guar gum was incorporated but increased when pollard or inulin was added. In many instances, different sources of the same fibre gave dramatically different impacts on the properties of cooked durum wheat pasta.

Long-Term Changes in Atrial Arrhythmia Burden After Renal Denervation Combined With Pulmonary Vein Isolation: SYMPLICITY-AF.

BACKGROUND: The autonomic nervous system plays an important role in atrial fibrillation (AF) and hypertension. Renal denervation (RDN) lowers blood pressure (BP), but its role in AF is poorly understood. OBJECTIVES: The purpose of this study was to investigate whether RDN reduces AF recurrence after pulmonary vein isolation (PVI). METHODS: This study randomized patients from 8 centers (United States, Germany) with drug-refractory AF for treatment with PVI+RDN vs PVI alone. A multielectrode radiofrequency Spyral catheter system was used for RDN. Insertable cardiac monitors were used for continuous rhythm monitoring. The primary efficacy endpoint was ≥2 minutes of AF recurrence or repeat ablation during all follow-up. The secondary endpoints included atrial arrhythmia (AA) burden, discontinuation of class I/III antiarrhythmic drugs, and BP changes from baseline. RESULTS: A total of 70 patients with AF (52 paroxysmal, 18 persistent) and uncontrolled hypertension were randomized (RDN+PVI, n = 34; PVI, n = 36). At 3.5 years, 26.2% and 21.4% of patients in RDN+PVI and PVI groups, respectively, were free from the primary efficacy endpoint (log rank P = 0.73). Patients with mean ≥1 h/d AA had less daily AA burden after RDN+PVI vs PVI (4.1 hours vs 9.2 hours; P = 0.016). More patients discontinued class I/III antiarrhythmic drugs after RDN+PVI vs PVI (45% vs 14%; P = 0.040). At 1 year, systolic BP changed by -17.8 ± 12.8 mm Hg and -13.7 ± 18.8 mm Hg after RDN+PVI and PVI, respectively (P = 0.43). The composite safety endpoint was not significantly different between groups. CONCLUSIONS: In patients with AF and uncontrolled BP, RDN+PVI did not prevent AF recurrence more than PVI alone. However, RDN+PVI may reduce AF burden and antiarrhythmic drug usage, but this needs further prospective validation.

Digital Technologies for Restorative Dentistry.

Although the accuracy of direct digitization of oral structure has been improved, indirect digitization is still required in specific situations such as full-arch scanning. Once accurate images are imported, efficient designing can be achieved by CAD software. Although smile design using a 3-dimensional facial scan better predicts planned restorations, further improvement in virtual articulators is needed for complex cases. Computer-aided manufacturing can be offered in several formats such as chairside, laboratory, or centralized fabrications. The subtractive technique is mainly used for restorations, and many chairside CAM materials are available now, but the additive technique has the potential to save materials and an advantage in fabricating complex geometries. Limited evidence is available in applying CAD/CAM technologies in implant restorations. However, it is used to fabricate custom implant abutments and crowns from various materials such as titanium, zirconia, and PEEK and hybrid crowns using stock titanium base abutments.

Reversible Deactivation Radical Polymerization: From Polymer Network Synthesis to 3D Printing.

3D printing has changed the fabrication of advanced materials as it can provide customized and on-demand 3D networks. However, 3D printing of polymer materials with the capacity to be transformed after printing remains a great challenge for engineers, material, and polymer scientists. Radical polymerization has been conventionally used in photopolymerization-based 3D printing, as in the broader context of crosslinked polymer networks. Although this reaction pathway has shown great promise, it offers limited control over chain growth, chain architecture, and thus the final properties of the polymer networks. More fundamentally, radical polymerization produces dead polymer chains incapable of postpolymerization transformations. Alternatively, the application of reversible deactivation radical polymerization (RDRP) to polymer networks allows the tuning of network homogeneity and more importantly, enables the production of advanced materials containing dormant reactivatable species that can be used for subsequent processes in a postsynthetic stage. Consequently, the opportunities that (photoactivated) RDRP-based networks offer have been leveraged through the novel concepts of structurally tailored and engineered macromolecular gels, living additive manufacturing and photoexpandable/transformable-polymer networks. Herein, the advantages of RDRP-based networks over irreversibly formed conventional networks are discussed.

Fortification of durum wheat spaghetti and common wheat bread with wheat bran protein concentrate-impacts on nutrition and technological properties.

Plant industrial by-products have generally low value but can be a good source of nutritional compounds. Wheat bran is the main by-product of wheat milling and contains >15% high-quality proteins. Extraction of wheat bran proteins (WBPC) and inclusion in spaghetti and bread formulations was studied to determine if the nutritional properties of these foods could be enhanced without deleterious effects on quality. Semolina was substituted with WBPC at 0, 1, 5, 10 and 20% (w/w) and made into spaghetti and a commercial bread flour was substituted with WBPC at 0, 1, 5 and 10% w/w and made into bread. Both spaghetti protein content (12.3 to 23.4%) and total essential amino acids (3.76 to 7.59%) increased with added WBPC. Overall spaghetti quality was acceptable up to 10%WBPC and superior to wholemeal, especially in appearance. However, the bread formulation used was very sensitive to WBPC especially above 1% addition.

Clusterin secretion is attenuated by the proinflammatory cytokines interleukin-1ß and tumor necrosis factor-α in models of cartilage degradation.

The protein clusterin has been implicated in the molecular alterations that occur in articular cartilage during osteoarthritis (OA). Clusterin exists in two isoforms with opposing functions, and their roles in cartilage have not been explored. The secreted form of clusterin (sCLU) is a cytoprotective extracellular chaperone that prevents protein aggregation, enhances cell proliferation and promotes viability, whereas nuclear clusterin acts as a pro-death signal. Therefore, these two clusterin isoforms may be putative molecular markers of repair and catabolic responses in cartilage and the ratio between them may be important. In this study, we focused on sCLU and used established, pathophysiologically relevant, in vitro models to understand its role in cytokine-stimulated cartilage degradation. The secretome of equine cartilage explants, osteochondral biopsies and isolated unpassaged chondrocytes was analyzed by western blotting for released sCLU, cartilage oligomeric protein (COMP) and matrix metalloproteinases (MMP) 3 and 13, following treatment with the proinflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α. Release of sulfated glycosaminoglycans (sGAG) was determined using the dimethylmethylene blue assay. Clusterin messenger RNA (mRNA) expression was quantified by quantitative real-time polymerase chain reaction. MMP-3, MMP-13, COMP, and sGAG release from explants and osteochondral biopsies was elevated with cytokine treatment, confirming cartilage degradation in these models. sCLU release was attenuated with cytokine treatment in all models, potentially limiting its cytoprotective function. Clusterin mRNA expression was down-regulated 7-days post cytokine stimulation. These observations implicate sCLU in catabolic responses of chondrocytes, but further studies are required to evaluate its role in OA and its potential as an investigative biomarker.

Influence of Durum Wheat Bran Particle Size on Phytochemical Content and on Leavened Bread Baking Quality.

Wheat bran is a conventional by-product of the wheat milling industry mainly used for animal feed. It is a rich and inexpensive source of phytonutrients, so is in demand for fibre-rich food products but creates quality issues when incorporated into bread. The purpose of this study was to characterize the physicochemical properties and phytochemical composition of different size durum bran fractions and show how they impact bread quality. Durum wheat (Triticum durum Desf.) was milled to create a coarse bran fraction (CB), which was further ground into a finer fraction (FB) which was sieved using four screens with apertures 425, 315, 250, 180, and <180 µm to create a particle size range of 1497 to 115 µm. All fractions contained phytosterol with highest in the 180 and FB, while total phenolic acids and antioxidant capacity was highest in CB and 425. Use of the fractions in a leavened common wheat (T. aestivum L.) bread formula at 10% incorporation negatively impacted bread loaf volume, colour, and texture compared to standard loaves, with CB having the least impact. Results suggest that to combine the highest phytochemical content with minimal impact on bread quality, bran particle size should be considered, with CB being the best choice.

Alterations in the chondrocyte surfaceome in response to pro-inflammatory cytokines.

BACKGROUND: Chondrocytes are exposed to an inflammatory micro-environment in the extracellular matrix (ECM) of articular cartilage in joint diseases such as osteoarthritis (OA) and rheumatoid arthritis (RA). In OA, degenerative changes and low-grade inflammation within the joint transform the behaviour and metabolism of chondrocytes, disturb the balance between ECM synthesis and degradation, and alter the osmolality and ionic composition of the micro-environment. We hypothesize that chondrocytes adjust their physiology to the inflammatory microenvironment by modulating the expression of cell surface proteins, collectively referred to as the 'surfaceome'. Therefore, the aim of this study was to characterize the surfaceome of primary equine chondrocytes isolated from healthy joints following exposure to the pro-inflammatory cytokines interleukin-1-beta (IL-1ß) and tumour necrosis factor-alpha (TNF-α). We employed combined methodology that we recently developed for investigating the surfaceome in stem cells. Membrane proteins were isolated using an aminooxy-biotinylation technique and analysed by mass spectrometry using high throughput shotgun proteomics. Selected proteins were validated by western blotting. RESULTS: Amongst the 431 unique cell surface proteins identified, a high percentage of low-abundance proteins, such as ion channels, receptors and transporter molecules were detected. Data are available via ProteomeXchange with identifier PXD014773. A high number of proteins exhibited different expression patterns following chondrocyte stimulation with pro-inflammatory cytokines. Low density lipoprotein related protein 1 (LPR-1), thrombospondin-1 (TSP-1), voltage dependent anion channel (VDAC) 1-2 and annexin A1 were considered to be of special interest and were analysed further by western blotting. CONCLUSIONS: Our results provide, for the first time, a repository for proteomic data on differentially expressed low-abundance membrane proteins on the surface of chondrocytes in response to pro-inflammatory stimuli.

In Situ Modification of Polyisoprene by Organo-Nanoclay during Emulsion Polymerization for Reinforcing Natural Rubber Thin Films.

Nanoclay-modified polyisoprene latexes were prepared and then used as a reinforcing component in natural rubber (NR) thin films. Starve-fed emulsion (SFE) polymerization gives a higher conversion than the batch emulsion (BE), while the gel and coagulation contents from both systems are comparable. This is attributed to the SFE that provides a smaller average polymer particle size which in turn results in a greater polymerization locus, promoting the reaction rate. The addition of organo-nanoclay during synthesizing polyisoprene significantly lessens the polymerization efficiency because the nanoclay has a potential to suppress nucleation process of the reaction. It also intervenes the stabilizing efficiency of the surfactant-SDS or sodium dodecyl sulfate, giving enlarged average sizes of the polymer particles suspended in the latexes. TEM images show that nanoclay particles are attached on and/or inserted in the polymer particles. XRD and thermal (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) analyses were employed to assess the d-spacing of nanoclay structure in NR nanocomposite films, respectively. Based on the overall results, 5 wt% of nanoclay relative to the monomer content utilized to alter the polyisoprene during emulsion polymerization is an optimum amount since the silicate plates of nanoclay in the composite exhibit the largest d-spacing which maximizes the extent of immobilized polymer constituent, giving the highest mechanical properties to the films. The excessive amounts of nanoclay used, i.e., 7 and 10 wt% relative to the monomer content, reduce the reinforcing power because of the re-agglomeration effect.

Molecular phenotyping of the surfaceome of migratory chondroprogenitors and mesenchymal stem cells using biotinylation, glycocapture and quantitative LC-MS/MS proteomic analysis.

The complement of cell surface proteins, collectively referred to as the surfaceome, is a useful indicator of normal differentiation processes, and the development of pathologies such as osteoarthritis (OA). We employed biochemical and proteomic tools to explore the surfaceome and to define biomarkers in chondrogenic progenitor cells (CPC) derived from human OA knee articular cartilage. These cells have great therapeutic potential, but their unexplored biology limits their clinical application. We performed biotinylation combined with glycocapture and high throughput shotgun proteomics to define the surface proteome of human bone marrow mesenchymal stem cells (MSCs) and human CPCs. We prepared cell surface protein-enriched fractions from MSCs and CPCs, and then a proteomic approach was used to compare and evaluate protein changes between undifferentiated MSCs and CPCs. 1256 proteins were identified in the study, of which 791 (63%) were plasma membrane, cell surface or extracellular matrix proteins. Proteins constituting the surfaceome were annotated and categorized. Our results provide, for the first time, a repository of quantitative proteomic data on the surfaceome of two closely related cell types relevant to cartilage biology and OA. These results may provide novel insights into the transformation of the surfaceome during chondrogenic differentiation and phenotypic changes during OA development.

Retrospective review of Arctic Front Advance Cryoballoon Ablation: a multicenter examination of second-generation cryoballoon (RADICOOL trial).

BACKGROUND: Pulmonary vein isolation (PVI) via catheter ablation is an approved therapy for patients with drug-refractory and symptomatic atrial fibrillation (AF). Furthermore, cryoballoon is now considered to be as effective as focal radiofrequency catheter ablation. This study examines the second-generation cryoballoon performance in a US multicenter review of real-world practices. METHODS: By retrospective chart collections, the long-term efficacy and safety of the cryoballoon procedure were assessed in 15 US centers. All patients had a history of drug-refractory symptomatic paroxysmal AF and were treated with a cryoballoon PVI strategy at the index ablation. RESULTS: Four hundred fifty-two patients were evaluated, and acute PVI was achieved in 99% of patients by cryoballoon catheter ablation. In 0.88% of patients (4/452), an additional focal ablation catheter was used to achieve acute PVI during the ablation procedure. Average procedure time was 128 (range 82 to 260) min, using an average of 17 (range 1 to 19) min of fluoroscopy. The most frequent adverse event was transient phrenic nerve injury (1.5%; 7/452 patients) which all resolved by the end of the procedure with no diaphragmatic dysfunction at discharge. There were no strokes, transient ischemic attacks, cardiac tamponade, atrioesophageal fistulas, or deaths during the study. At the 12-month efficacy endpoint, single-procedure success of freedom from atrial arrhythmia was 87% (393/452 patients). CONCLUSIONS: This real-world examination of the US practice demonstrates that second-generation cryoballoon ablation by PVI strategy is safe and effective among patients with paroxysmal AF.

Characterisation of a divergent progenitor cell sub-populations in human osteoarthritic cartilage: the role of telomere erosion and replicative senescence.

In recent years it has become increasingly clear that articular cartilage harbours a viable pool of progenitor cells and interest has focussed on their role during development and disease. Analysis of progenitor numbers using fluorescence-activated sorting techniques has resulted in wide-ranging estimates, which may be the result of context-dependent expression of cell surface markers. We have used a colony-forming assay to reliably determine chondroprogenitor numbers in normal and osteoarthritic cartilage where we observed a 2-fold increase in diseased tissue (P < 0.0001). Intriguingly, cell kinetic analysis of clonal isolates derived from single and multiple donors of osteoarthritic cartilage revealed the presence of a divergent progenitor subpopulation characterised by an early senescent phenotype. Divergent sub-populations displayed increased senescence-associated ß-galactosidase activity, lower average telomere lengths but retained the capacity to undergo multi-lineage differentiation. Osteoarthritis is an age-related disease and cellular senescence is predicted to be a significant component of the pathological process. This study shows that although early senescence is an inherent property of a subset of activated progenitors, there is also a pool of progenitors with extended viability and regenerative potential residing within osteoarthritic cartilage.