Effects on human heart valve immunogenicity in vitro by high concentration cryoprotectant treatment

It has been shown previously that cryopreservation, using an ice‐free cryopreservation method with the cryoprotectant formulation VS83, beneficially modulated immune reactions in vivo and in vitro when compared with conventionally frozen tissues. In this study, we assessed the impact of a VS83 post‐treatment of previously conventionally frozen human tissue on responses of human immune cells in vitro. Tissue punches of treated and non‐treated (control) aortic heart valve tissue (leaflets and associated aortic root) were co‐cultured for 7 days with peripheral blood mononuclear cells or enriched CD14⁺ monocytes. Effects on cellular activation markers, cytokine secretion and immune cell proliferation were analysed by flow cytometry. Flow cytometry studies showed that VS83 treatment of aortic root tissue promoted activation and differentiation of CD14⁺ monocytes, inducing both up‐regulation of CD16 and down‐regulation of CD14. Significantly enhanced expression levels for the C‐C chemokine receptor (CCR)7 and the human leukocyte antigen (HLA)‐DR on monocytes co‐cultured with VS83‐treated aortic root tissue were measured, while the interleukin (IL)‐6 and monocyte chemoattractant protein (MCP)‐1 release was suppressed. However, the levels of interferon (IFN)γ and tumour necrosis factor (TNF)α remained undetectable, indicating that complete activation into pro‐inflammatory macrophages did not occur. Similar, but non‐significant, changes occurred with VS83‐treated leaflets. Additionally, in co‐cultures with T cells, proliferation and cytokine secretion responses were minimal. In conclusion, post‐treatment of conventionally cryopreserved human heart valve tissue with the VS83 formulation induces changes in the activation and differentiation characteristics of human monocytes, and thereby may influence long‐term performance following implantation. Copyright © 2017 John Wiley & Sons, Ltd.     

Deformation strain is the main physical driver for skeletal precursors to undergo osteogenesis in earlier stages of osteogenic cell maturation

Mesenchymal stem cells play a major role during bone remodelling and are thus of high interest for tissue engineering and regenerative medicine applications. Mechanical stimuli, that is, deformation strain and interstitial fluid‐flow‐induced shear stress, promote osteogenic lineage commitment. However, the predominant physical stimulus that drives early osteogenic cell maturation is not clearly identified. The evaluation of each stimulus is challenging, as deformation and fluid‐flow‐induced shear stress interdepend. In this study, we developed a bioreactor that was used to culture mesenchymal stem cells harbouring a strain‐responsive AP‐1 luciferase reporter construct, on porous scaffolds. In addition to the reporter, mineralization and vitality of the cells was investigated by alizarin red staining and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide. Quantification of the expression of genes associated to bone regeneration and bone remodelling was used to confirm alizarin red measurements. Controlled perfusion and deformation of the 3‐dimensional scaffold facilitated the alteration of the expression of osteogenic markers, luciferase activity, and calcification. To isolate the specific impact of scaffold deformation, a computational model was developed to derive a perfusion flow profile that results in dynamic shear stress conditions present in periodically loaded scaffolds. In comparison to actually deformed scaffolds, a lower expression of all measured readout parameters indicated that deformation strain is the predominant stimulus for skeletal precursors to undergo osteogenesis in earlier stages of osteogenic cell maturation.     

A Review of Prompt-Fading Procedures: Implications for Effective and Efficient Skill Acquisition

This paper reports a systematic review of prompt-fading research, with a focus on experiments comparing two or more prompt-fading procedures. Forty-five articles with 46 experiments met the operationally-defined inclusion criteria. For the selected articles, data on several variables were extracted and analyzed. Research demonstrated that all prompt-fading procedures were generally effective in promoting acquisition of behavior. Stimulus prompting was more effective and efficient when compared to response-prompting procedures. Comparisons of response-prompting procedures yielded variable efficiency results. These outcomes are discussed in terms of the behavioral principles that facilitate transfer of stimulus control from the prompt to the discriminative stimulus, such as blocking and overshadowing. Basic investigations of the role of these behavioral principles might help develop prompt-fading procedures that are consistently effective across participants. Implications for research include suggestions for the development of individualized assessments of stimulus control, similar to the functional analysis methodology.     

Developing research priorities for nurses working in the gynaecology setting in Western Australia

Background

Nurses working in clinical settings are instrumental to translating research into practice. The Delphi approach has been used by clinicians worldwide to set research agendas relevant to their clinical work.

A cross-sectional survey of factors associated with the uptake of smoking cessation aids among smokers and ex-smokers

Background: A cross-sectional survey was conducted in Germany via the online panel PsyWeb with the aim of assessing factors associated with the uptake of smoking cessation aids among smokers and ex-smokers.

Methods: Of the 10,000 panel members invited to participate in the survey, 624 took part.

Main Outcome Measures: Outcomes were measured via questionnaires to assess the uptake of smoking cessation aids, health literacy, readiness to change smoking behavior, and the Fagerström Test for Nicotine Dependence.

Results: There was no association between gender or educational status and use of smoking cessation aids according to chi-square tests of independence. Logistic regression showed that health literacy, degree of tobacco dependence, and readiness to change were significantly associated with the uptake of smoking cessation aids. Smokers with a high degree of nicotine dependence, high readiness to change, and low health literacy were more likely to use aids.

Conclusion: The survey results can be used to develop psychological approaches and interventions to promote smoking cessation, e.g., interventions to increase readiness to change among smokers may increase the uptake of aids. Moreover, the results may help to improve patient care by disseminating information on effective aids and thereby promoting smoking cessation among relevant patient groups.     

Frailty assessment and impact of frailty on outcomes after transcatheter aortic valve replacement

Introduction: Certain frail patients fail to achieve adequate functional or mortality benefit despite successful transcatheter aortic valve replacement (TAVR). Therefore, frailty assessment methods are becoming an important tool to identify and intervene on this high-risk patient subset for improving clinical outcomes.

Areas covered: The authors provide an overview of frailty and frailty assessment tools being used in clinical practice and discuss the impact of frailty on the cardiac patients, particularly among the TAVR population.

Expert commentary: Available evidence suggests that frailty assessment is critical for identifying patients at high risk of morbidity and mortality after TAVR procedures. However, there is lack of consensus for the best methodology to determine frailty and its optimal management in TAVR populations. Although, physical exercise is a commonly employed intervention to reduce frailty, a greater attention towards improving nutrition may convey more benefit than either intervention alone. Ongoing studies are investigating the benefits of a multicomponent approach to improve clinical outcomes in frail patients undergoing TAVR.