Altered Bone Material Properties in HLA‐B27 Rats Include Reduced Mineral to Matrix Ratio and Altered Collagen Cross‐Links

Spondyloarthropathy and inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, are often associated with severe osteopenia/osteoporosis in both children and adults. HLA‐B27 transgenic rats present a phenotype that includes severe colitis and severely accelerated alveolar bone loss. The purpose of this study was to evaluate long bone density status, systemic bone metabolic markers, and intrinsic bone material properties in HLA‐B27 transgenic (TG) rats, and compare them with those of age‐ and sex‐matched wild‐type (WT) animals. The results indicate that in the HLA‐B27 rat, an animal susceptible to both alveolar bone loss (ABL) and long bone osteopenia, there is a statistically significant negative correlation between ABL and long bone bone mineral density (BMD), as well as mineral/matrix ratio at active bone‐forming trabecular surfaces. The TG animals had a lower mineral/matrix ratio and higher relative proteoglycan and advanced glycation end product (?‐N‐Carboxymethyl‐L‐lysine) content and pyridinoline/divalent collagen cross‐link ratio compared with WT. These results may provide better understanding of the interrelationship between osteoporosis and oral bone loss, the underlying causes of the inferior bone strength in the HLA‐B27 transgenic animals, and could prove to be a useful model in the elucidation of the pathophysiology of spondyloarthropathy and IBD‐associated osteopenia/osteoporosis and in the evaluation of pharmacological intervention(s) against such conditions. © 2014 American Society for Bone and Mineral Research.     

An approach for modelling multiple correlated outcomes in a network of interventions using odds ratios

A multivariate meta‐analysis of two or more correlated outcomes is expected to improve precision compared with a series of independent, univariate meta‐analyses especially when there are studies reporting some but not all outcomes. Multivariate meta‐analysis requires estimates of the within‐study correlations, which are seldom available. Existing methods for analysing multiple outcomes simultaneously are limited to pairwise treatment comparisons. We propose a model for a joint, simultaneous synthesis of multiple dichotomous outcomes in a network of interventions and introduce a simple way to elicit expert opinion for the within‐study correlations by utilizing a set of conditional probability parameters. We implement our multiple‐outcomes network meta‐analysis model within a Bayesian framework, which allows incorporation of expert information. As an example, we analyse two correlated dichotomous outcomes, response to the treatment and dropout rate, in a network of pharmacological interventions for acute mania. The produced estimates have narrower confidence intervals compared with the simple network meta‐analysis. We conclude that the proposed model and the suggested prior elicitation method for correlations constitute a useful framework for performing network meta‐analysis for multiple outcomes. Copyright © 2014 John Wiley & Sons, Ltd.     

Vasomotor responses of coronary stenoses to acetylcholine and their relation to serum lipid levels in stable angina pectoris

The effects of acetylcholine administration on coronary stenoses in relation to serum lipids level were evaluated in 18 patients (15 men, 3 women) with coronary artery disease and stable angina. Intracoronary acetylcholine was infused in concentrations 10⁻⁷, 10^−6, 10⁻⁵ M, followed by intracoronary bolus administration of isosorbide dinitrate. Computerized angiography was used to assess the changes in the diameter of stenoses and of proximal and distal segments. During acetylcholine infusion, at concentrations between 10⁻⁷ to 10 ⁻⁵M, there was a significant (p <0.01) dose-dependent constriction of proximal and distal segments and of stenoses reversed by isosorbide dinitrate. There was no correlation between the serum total cholesterol level and the responses of proximal and distal segments to acetylcholine or nitrate. A correlation (p <0.05) was found between the serum total cholesterol level and the response of stenoses to acetylcholine, but there was no correlation with the response to isosorbide dinitrate. In conclusion, in patients with stable angina current serum total cholesterol level correlates with the vasomotor response of coronary stenoses to intracoronary acetylcholine. These findings are consistent with a direct effect of cholesterol, increasing basal coronary vasomotor tone and increasing the stimulated vasoconstrictor response of stenoses.     

Evaluation of the genetic damage to workers in a Greek shipyard

Shipyards are industrial areas where workers are likely exposed to environmental pollutants such as welding fumes, fine organic solvent and dye dust, that render the occupational environment a high risk one. Assessing the risk that workers are exposed to is a high critical factor in improving their working conditions. The present study aims to investigate the potential genetic damage to workers exposed to a harsh environment in a Greek shipyard. It is focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of shipyard workers’ oral mucosa epithelium by implementing the buccal micronucleus cytome assay. Exposed workers appeared with statistically significant induced micronuclei as compared to office employees. Statistically, significant cell lesions were detected and are related to workers’ exposure to environmental conditions. The workers’ smoking habit contributed as well to the observed buccal epithelial cell alterations. The observed data signify the high-risk workers are exposed; resulting in the shipyard’s management the need to implement measures improving the working environment conditions and to reevaluate the workers’ personal protective equipment requirements.