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Introduction Continuity of care by family physicians in primary care settings may play a role in reducing health resource utilization and improving clinical outcomes and satisfaction of patients with chronic obstructive pulmonary disease. Clear evidence on the impact of continuity of care will support clinical programing and integration of services across health settings.Methods The association between continuity of care and unplanned health service utilization in persons with a diagnosis of chronic obstructive pulmonary disease in a rural region in Ontario, Canada was evaluated. A retrospective cohort study was conducted using population-level health administrative data. The main exposure variable was continuity of care.Results A continuity of care index was calculated for patients with at least five visits to a healthcare provider during the 5-year follow-up period (n=  40,033). Higher continuity of care (n=  20,008) and lower continuity of care (n=  20,025), based on the median continuity of care score were calculated. Patients with lower continuity of care had an increased adjusted relative risk of 2.12 (2.08, 2.33) of an emergency department visit, 2.81 (2.72, 2.9) risk of hospitalization, and 3.52 (3.24, 3.82) of being readmitted to hospital compared to those with higher continuity of care.Discussion An association between continuity of care and unplanned health services utilization, where a lower use of unplanned health services was observed in the cohort of patients with chronic obstructive pulmonary disease experiencing higher continuity of care. Continuity of care makes philosophical and social sense in that care is provided by a known provider to a known patient and unnecessary investigations can be avoided.

Abstract

Identification of single nucleotide polymorphisms (SNPs) associated with gene expression levels, known as expression quantitative trait loci (eQTLs), may improve understanding of the functional role of phenotype-associated SNPs in genome-wide association studies (GWAS). The small sample sizes of some previous eQTL studies have limited their statistical power. We conducted an eQTL investigation of microarray-based gene and exon expression levels in whole blood in a cohort of 5257 individuals, exceeding the single cohort size of previous studies by more than a factor of 2. We detected over 19,000 independent lead cis-eQTLs and over 6000 independent lead trans-eQTLs, targeting over 10,000 gene targets (eGenes), with a false discovery rate (FDR) < 5%. Of previously published significant GWAS SNPs, 48% are identified to be significant eQTLs in our study. Some trans-eQTLs point toward novel mechanistic explanations for the association of the SNP with the GWAS-related phenotype. We also identify 59 distinct blocks or clusters of trans-eQTLs, each targeting the expression of sets of six to 229 distinct trans-eGenes. Ten of these sets of target genes are significantly enriched for microRNA targets (FDR < 5%). Many of these clusters are associated in GWAS with multiple phenotypes. These findings provide insights into the molecular regulatory patterns involved in human physiology and pathophysiology. We illustrate the value of our eQTL database in the context of a recent GWAS meta-analysis of coronary artery disease and provide a list of targeted eGenes for 21 of 58 GWAS loci.

Tissue engineering has shown promise for the development of constructs to facilitate large volume soft tissue augmentation in reconstructive and cosmetic plastic surgery. This article reviews the key progress to date in the field of adipose tissue engineering. In order to effectively design a soft tissue substitute, it is critical to understand the native tissue environment and function. As such, the basic physiology of adipose tissue is described and the process of adipogenesis is discussed. In this article, we have focused on tissue engineering using a cell-seeded scaffold approach, where engineered extracellular matrix substitutes are seeded with exogenous cells that may contribute to the regenerative response. The strengths and limitations of each of the possible cell sources for adipose tissue engineering, including adipose-derived stem cells, are detailed. We briefly highlight some of the results from the major studies to date, involving a range of synthetic and naturally derived scaffolds. While these studies have shown that adipose tissue regeneration is possible, more research is required to develop optimized constructs that will facilitate safe, predictable, and long-term augmentation in clinical applications.

A successful regenerative therapy to treat damage incurred after an ischemic event in the heart will require an integrated approach including methods for appropriate revascularization of the infarct site, mechanical recovery of damaged tissue, and electrophysiological coupling with native cells. Cardiomyocytes are the ideal cell type for heart regeneration because of their inherent electrical and physiological properties, and cardiomyocytes derived from embryonic stem cells (ESCs) represent an attractive option for tissue-engineering therapies. An important step in developing tissue engineeringbased approaches to cardiac cell therapy is understanding how scaffold architecture affects cell behavior. In this work, we generated large numbers of ESC-derived cardiomyocytes in bioreactors and seeded them on porous, 3-dimensional scaffolds prepared using 2 different techniques: electrospinning and thermally induced phase separation (TIPS). The effect of material macro-architecture on the adhesion, viability, and morphology of the seeded cells was determined. On the electrospun scaffolds, cells were elongated in shape, a morphology typical of cultured ESC-derived cardiomyocytes, whereas on scaffolds fabricated using TIPS, the cells retained a rounded morphology. Despite these gross phenotypic and physiological differences, sarcomeric myosin and connexin 43 expression was evident, and contracting cells were observed on both scaffold types, suggesting that morphological changes induced by material macrostructure do not directly correlate to functional differences.

In the past 30 years, the development and use of artificial skin in the treatment of acute and chronic wounds has advanced from an experimental concept to a working reality. However, while there have been an increasing number of artificial skin substitutes licensed for clinical use, they have yet to supplant the current gold standard of an autologous tissue graft for most applications. This article reviews the advantages and disadvantages of the currently available, biologically based substitutes, with special emphasis on their relative efficacy and suitability for treatment of particular wound types. Economic considerations, desirable improvements of currently available materials and the potential impact of future advances in the field will also be discussed.

Dermal substitutes derived from xenograft materials require elaborate processing at a considerable cost. Acellularized porcine dermis is a readily available material associated with minimal immunogenicity. The objective of this study was to evaluate acellularized pig dermis as a scaffold for human fibroblasts.

Polyacrylate films in the absence of added endotoxin caused rat peritoneal macrophages to secrete a small amount of TNFα. There was little difference, if any, among the materials, which included various co or terpolymers of hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid, methyl methacrylate, and butyl methacrylate. The materials were surface characterized and endotoxin cleaned prior to testing. Equivalent endotoxin levels associated with the material were <0.03 EUmL for all materials but two; for polyHEMA, the most contaminated material, it was 0.23 EUmL. Films of the materials were incubated with freshly isolated rat peritoneal macrophages for 6 to 24 h before the TNFα levels in the supernatant were analyzed for biological activity, using L929 cells as a target. When endotoxin was added, far greater quantities of TNFα were generated at 24 h compared to 6 h, but still there was little effect with regard to material chemistry. Such an in vitroassay proved not to be useful for the screening of potential microencapsulation materials for peritoneal biocompatibility. © 1999 John Wiley & Sons, Inc. J Biomed Mater Res, 46, 324–330, 1999.

No relevant conflicts of interest to declare.

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