Supporting Conservation: The Roles of Flagship Species and Identifiable Victims

Psychological insights into human behaviour can have enormous applied value for promoting charitable giving. Nevertheless, the application of these insights to conservation appeals featuring non-human animals has scarcely been explored. Although people often donate more when presented with single 'identifiable' victims, whether this effect also extends to non-humans is not known. Similarly, although many conservation appeals feature flagship species, it is unclear whether flagship species generate increased donations. We experimentally investigated how (i) identifiable versus statistical beneficiaries and (ii) flagship versus non-flagship species affected donations to a conservation charity. Unexpectedly, subjects did not donate more when presented with single identifiable beneficiaries rather than groups of beneficiaries. Flagship species, on the other hand, increased donation amounts relative to appeals featuring non-flagship species. We discuss how these findings can inform and improve the effectiveness of conservation fundraising appeals

Remineralising composites with improved cytocompatibility and containing antimicrobial agents for conservative treatment of caries

Objectives: To develop a remineralising dental composite with high strength, conversion and cytocompatibility and antimicrobial potential for more conservative treatment of dental caries. / Methods: The effect of glass filler particle size distributions and glass fibres on wetpoint, handling and mechanical properties was assessed. The effect of two photoinitiators at varying concentrations and four co-initiators on conversion, cytocompatibility and mechanical properties was determined. The conversion, depth of cure, shrinkage, mechanical properties, water sorption and cytocompatibility of composites containing varying bulk (urethane dimethacrylate (UDMA), bisphenol A glycidyl methacrylate (Bis-GMA)) and diluent monomers (poly(propylene glycol) dimethacrylate (PPGDMA), tri(ethylene glycol) dimethacrylate (TEGDMA)) were characterised. The conversion, water sorption, calcium precipitation, mechanical properties and shear bond strength of composites containing remineralising and antimicrobial agents (monocalcium phosphate (MCP), tricalcium phosphate (TCP), ε- poly-L-lysine (εPL)) were assessed (storage in water, simulated body fluid (SBF), artificial saliva (AS)). Techniques included Fourier transform infrared spectroscopy, mass and volume determination, biaxial flexural testing, shear bond testing, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, resazurin, WST-8 and MTS assays. / Results: An optimal combination of fillers was established. Conversion was affected by co-initiator to a greater extent than photoinitiator. Composites containing UDMA and PPGDMA had the optimal balance of conversion, mechanical properties, depth of cure and cytocompatibility without increased shrinkage. Composites containing MCP with either TCP or εPL induced rapid hydroxyapatite formation on the surface of the composite within one week in SBF but not in AS or water. / Significance: Composites containing the newly developed liquid phase had high conversion and strength, slightly improved cytocompatibility and acceptable shrinkage. Whilst composites containing MCP and TCP were stronger, the added possible antimicrobial action of those containing MCP and εPL have great potential to defend against recurrent caries by preventing microbial microleakage

Poly(propylene glycol) and urethane dimethacrylates improve conversion of dental composites and reveal complexity of cytocompatibility testing.

OBJECTIVES: To determine the effects of various monomers on conversion and cytocompatibility of dental composites and to improve these properties without detrimentally affecting mechanical properties, depth of cure and shrinkage. METHODS: Composites containing urethane dimethacrylate (UDMA) or bisphenol A glycidyl methacrylate (Bis-GMA) with poly(propylene glycol) dimethacrylate (PPGDMA) or triethylene glycol dimethacrylate (TEGDMA) were characterized using the following techniques: conversion (FTIR at 1 and 4mm depths), depth of cure (BS EN ISO 4049:2009 and FTIR), shrinkage (BS EN ISO 17304:2013 and FTIR), strength and modulus (biaxial flexural test) and water sorption. Cytocompatibility of composites and their liquid phase components was assessed using three assays (resazurin, WST-8 and MTS). RESULTS: UDMA significantly improved conversion, BFS and depth of cure compared to Bis-GMA, without increasing shrinkage. UDMA was cytotoxic at lower concentrations than Bis-GMA, but extracts of Bis-GMA-containing composites were less cytocompatible than of those containing UDMA. PPGDMA improved conversion and depth of cure compared to TEGDMA, without detrimentally affecting shrinkage. TEGDMA was shown by all assays to be highly toxic. Resazurin, but not WST-8 and MTS, suggested that PPGDMA exhibited improved cytocompatibility compared to TEGDMA. SIGNIFICANCE: The use of UDMA and PPGDMA results in composites with excellent conversion, depth of cure and mechanical properties, without increasing shrinkage. Composites containing UDMA appear to be slightly more cytocompatible than those containing Bis-GMA. These monomers may therefore improve the material properties of dental restorations, particularly bulk fill materials. The effect of diluent monomer on cytocompatibility requires further investigation

Evaluation of decellularization protocols for production of tubular small intestine submucosa scaffolds for use in oesophageal tissue engineering.

Small intestine submucosa (SIS) has emerged as one of a number of naturally derived extracellular matrix (ECM) biomaterials currently in clinical use. In addition to clinical applications, ECM materials form the basis for a variety of approaches within tissue engineering research. In our preliminary work it was found that SIS can be consistently and reliably made into tubular scaffolds which confer certain potential advantages. Given that decellularization protocols for SIS are applied to sheet-form SIS, it was hypothesized that a tubular-form SIS would behave differently to pre-existing protocols. In this work, tubular SIS was produced and decellularized by the conventional peracetic acid-agitation method, peracetic acid under perfusion along with two commonly used detergent-perfusion protocols. The aim of this was to produce a tubular SIS that was both adequately decellularized and possessing the mechanical properties which would make it a suitable scaffold for oesophageal tissue engineering, which was one of the goals of this work. Analysis was carried out via mechanical tensile testing, DNA quantification, scanning electron and light microscopy, and a metabolic assay, which was used to give an indication of the biocompatibility of each decellularization method. Both peracetic acid protocols were shown to be unsuitable methods with the agitation-protocol-produced SIS, which was poorly decellularized, and the perfusion protocol resulted in poor mechanical properties. Both detergent-based protocols produced well-decellularized SIS, with no adverse mechanical effects; however, one protocol emerged, SDS/Triton X-100, which proved superior in both respects. However, this SIS showed reduced metabolic activity, and this cytotoxic effect was attributed to residual reagents. Consequently, the use of SIS produced using the detergent SD as the decellularization agent was deemed to be the most suitable, although the elimination of the DNase enzyme would give further improvement

Strontium- and calcium-containing, titanium-stabilised phosphate-based glasses with prolonged degradation for orthopaedic tissue engineering.

Strontium- and calcium-releasing, titanium-stabilised phosphate-based glasses with a controlled degradation rate are currently under development for orthopaedic tissue engineering applications. Ca and/or Sr were incorporated at varying concentrations in quaternary phosphate-based glasses, in order to promote osteoinduction. Ti was incorporated at a fixed concentration in order to prolong degradation. Glasses of the general formula (P2O5)-(Na2O)-(TiO2)-(CaO)-(SrO) were prepared via the melt-quench technique. The materials were characterised by energy-dispersive X-ray spectroscopy, X-ray diffraction, (31)P magic angle spinning nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential thermal analysis and density determination. The dissolution rate in distilled water was determined by measuring mass loss, ion release and pH change over a two-week period. In addition, the cytocompatibility and alkaline phosphatase activity of an osteoblast-like cell line cultured on the surface of glass discs was assessed. The glasses were shown to be amorphous and contained Q(1), Q(2) and Q(3) species. Fourier transform infrared spectroscopy revealed small changes in the glass structure as Ca was substituted with Sr and differential thermal analysis confirmed a decrease in crystallisation temperature with increasing Sr content. Degradation and ion release studies also showed that mass loss was positively correlated with Sr content. These results were attributed to the lower electronegativity of Sr in comparison to Ca favouring the formation of phosphate-based mineral phases. All compositions supported cell proliferation and survival and induced at least 2.3-fold alkaline phosphatase activity relative to the control. Glass containing 17.5 mol% Sr had 3.6-fold greater alkaline phosphatase activity than the control. The gradual release of Ca and Sr supported osteoinduction, indicating their potential suitability in orthopaedic tissue engineering applications

Differential effects of bile acids on the postprandial secretion of gut hormones: a randomized crossover study.

Bile acids (BA) regulate postprandial metabolism directly and indirectly by affecting the secretion of gut hormones like glucagon-like peptide-1 (GLP-1). The postprandial effects of BA on the secretion of other metabolically active hormones are not well understood. The objective of this study was to investigate the effects of oral ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) on postprandial secretion of GLP-1, oxyntomodulin (OXM), peptide YY (PYY), glucose-dependent insulinotropic peptide (GIP), glucagon, and ghrelin. Twelve healthy volunteers underwent a mixed meal test 60 min after ingestion of UDCA (12-16 mg/kg), CDCA (13-16 mg/kg), or no BA in a randomized crossover study. Glucose, insulin, GLP-1, OXM, PYY, GIP, glucagon, ghrelin, and fibroblast growth factor 19 were measured prior to BA administration at -60 and 0 min (just prior to mixed meal) and 15, 30, 60, 120, 180, and 240 min after the meal. UDCA and CDCA provoked differential gut hormone responses; UDCA did not have any significant effects, but CDCA provoked significant increases in GLP-1 and OXM and a profound reduction in GIP. CDCA increased fasting GLP-1 and OXM secretion in parallel with an increase in insulin. On the other hand, CDCA reduced postprandial secretion of GIP, with an associated reduction in postprandial insulin secretion. Exogenous CDCA can exert multiple salutary effects on the secretion of gut hormones; if these effects are confirmed in obesity and type 2 diabetes, CDCA may be a potential therapy for these conditions. NEW & NOTEWORTHY: Oral CDCA and UDCA have different effects on gut and pancreatic hormone secretion. A single dose of CDCA increased fasting secretion of the hormones GLP-1 and OXM with an accompanying increase in insulin secretion. CDCA also reduced postprandial GIP secretion, which was associated with reduced insulin. In contrast, UDCA did not change gut hormone secretion fasting or postprandially. Oral CDCA could be beneficial to patients with obesity and diabetes

EQ-5D in skin conditions: an assessment of validity and responsiveness

Aims and objectives This systematic literature review aims to assess the reliability, validity and responsiveness of three widely used generic preference-based measures of health-related quality of life (HRQL), i.e., EQ-5D, Health Utility Index 3 (HUI3) and SF-6D in patients with skin conditions. Methods A systematic search was conducted to identify studies reporting health state utility values obtained using EQ-5D, SF-6D, or HUI3 alongside other HRQL measures or clinical indices for patients with skin conditions. Data on test-retest analysis for reliability, known group differences or correlation and regression analyses for validity, and change over time or responsiveness indices analysis were extracted and reviewed. Results A total of 16 papers reporting EQ-5D utilities in people with skin conditions were included in the final review. No papers for SF-6D and HUI3 were found. Evidence of reliability was not found for any of these measures. The majority of studies included in the review (12 out of 16) examined patients with plaque psoriasis or psoriatic arthritis and the remaining four studies examined patients with either acne, hidradenitis suppurativa, hand eczema, or venous leg ulcers. The findings were generally positive in terms of performance of EQ-5D. Six studies showed that EQ-5D was able to reflect differences between severity groups and only one reported differences that were not statistically significant. Four studies found that EQ-5D detected differences between patients and the general population, and differences were statistically different for three of them. Further, moderate-to-strong correlation coefficients were found between EQ-5D and other skin-specific HRQL measures in four studies. Eight studies showed that EQ-5D was able to detect change in HRQL appropriately over time and the changes were statistically significant in seven studies. Conclusions Overall, the validity and responsiveness of the EQ-5D was found to be good in people with skin diseases, especially plaque psoriasis or psoriatic arthritis. No evidence on SF-6D and HUI3 was available to enable any judgments to be made on their performance