475 research outputs found
Perceptions and Reasons Regarding E-Cigarette Use among Users and Non-Users: A Narrative Literature Review.
This paper aims to provide an in-depth understanding of the attractiveness of e-cigarettes for several different groups. For this purpose, perceptions of and reasons for e-cigarette use were systematically reviewed as reported by e-cigarette users, cigarette smokers, dual users, and non-users, among both adults and youth. MEDLINE® and Scopus were used to search for relevant articles, and references of included studies were also investigated. Two reviewers screened all titles and abstracts independently, blinded to authors and journal titles (Cohen’s Kappa = 0.83), resulting in 72 eligible articles. Risk perceptions, perceived benefits, and reasons for e-cigarette use were categorized in themes and sub-themes. Risk perceptions included harmfulness in general, and specific health risks. Perceived benefits included improved taste and smell, and safety for bystanders. Reasons for use included (health) benefits, curiosity, smoking cessation, and friends using e-cigarettes. The findings highlight that there is a variety of perceptions and reasons mentioned by adult and youth e-cigarette users, cigarette smokers, dual users, and non-users. As such, this overview provides valuable information for scientists, public health professionals, behavior change experts, and regulators to improve future research, risk communication, and possibilities to effectively regulate e-cigarettes
Using High-Field Magnetic Resonance Imaging to Estimate Distensibility of the Middle Cerebral Artery
Sorting living mesenchymal stem cells using a TWIST1 RNA-based probe depends on incubation time and uptake capacity
Bone marrow derived mesenchymal stromal cells (BMSCs) are multipotent progenitors of particular interest for cell-based tissue engineering therapies. However, one disadvantage that limit their clinical use is their heterogeneity. In the last decades a great effort was made to select BMSC subpopulations based on cell surface markers, however there is still no general consensus on which markers to use to obtain the best BMSCs for tissue regeneration. Looking for alternatives we decided to focus on a probe-based method to detect intracellular mRNA in living cells, the SmartFlare technology. This technology does not require fixation of the cells and allows us to sort living cells based on gene expression into functionally different populations. However, since the technology is available it is debated whether the probes specifically recognize their target mRNAs. We validated the TWIST1 probe and demonstrated that it specifically recognizes TWIST1 in BMSCs. However, differences in probe concentration, incubation time and cellular uptake can strongly influence signal specificity. In addition we found that TWIST1high expressing cells have an increased expansion rate compared to TWIST1low expressing cells derivedfrom the same initial population of BMSCs. The SmartFlare probes recognize their target gene, however for each probe and cell type validation of the protocol is necessary
Assessing the importance of internal and external self-esteem and their relationship to honor concerns in six countries
We assessed empirical support for (a) the widely held notion that across so-called “honor, dignity, and face cultures,” internal and external components of self-esteem are differentially important for overall self-esteem; and (b) the idea that concerns for honor are related to internal and external components of self-esteem in honor cultures but not in dignity and face cultures. Most importantly, we also set out to (c) investigate whether measures are equivalent, that is, whether a comparison of means and relationships across cultural groups is possible with the employed scales. Data were collected in six countries (N = 1,099). We obtained only metric invariance for the self-esteem and honor scales, allowing for comparisons of relationships across samples, but not scale means. Partly confirming theoretical ideas on the importance of internal and external components of self-esteem, we found that only external rather than both external and internal self-esteem was relatively more important for overall self-esteem in “honor cultures”; in a “dignity” culture, internal self-esteem was relatively more important than external self-esteem. Contrary to expectations, in a “face” culture, internal self-esteem was relatively more important than external self-esteem. We were not able to conceptually replicate earlier reported relationships between components of self-esteem and the concern for honor, as we observed no cultural differences in the relationship between self-esteem and honor. We point toward the need for future studies to consider invariance testing in the field of honor to appropriately understand differences and similarities between samples
Fc galactosylation promotes hexamerization of human IgG1, leading to enhanced classical complement activation
Human IgG contains one evolutionarily conserved N-linked glycan in its Fc region at position 297. This glycan is crucial for Fc-mediated functions, including its induction of the classical complement cascade. This is induced after target recognition through the IgG-Fab regions, allowing neighboring IgG-Fc tails to associate through Fc:Fc interaction, ultimately leading to hexamer formation. This hexamerization seems crucial for IgG to enable efficient interaction with the globular heads of the first complement component C1q and subsequent complement activation. In this study, we show that galactose incorporated in the IgG1-Fc enhances C1q binding, C4, C3 deposition, and complement-dependent cellular cytotoxicity in human erythrocytes and Raji cells. IgG1-Fc sialylation slightly enhanced binding of C1q, but had little effect on downstream complement activation. Using various mutations that decrease or increase hexamerization capacity of IgG1, we show that IgG1-Fc galactosylation has no intrinsic effect on C1q binding to IgG1, but enhances IgG1 hexamerization potential and, thereby, complement activation. These data suggest that the therapeutic potential of Abs can be amplified without introducing immunogenic mutations, by relatively simple glycoengineering.Proteomic
Mixed reality visualization in shoulder arthroplasty: is it better than traditional preoperative planning software?
Background Preoperative traditional software planning (TSP) is a method used to assist surgeons with implant selection and glenoid guide-pin insertion in shoulder arthroplasty. Mixed reality (MR) is a new technology that uses digital holograms of the preoperative plan and guide-pin trajectory projected into the operative field. The purpose of this study was to compare TSP to MR in a simulated surgical environment involving insertion of guide-pins into models of severely deformed glenoids. Methods Eight surgeons inserted guide-pins into eight randomized three-dimensional-printed severely eroded glenoid models in a simulated surgical environment using either TSP or MR. In total, 128 glenoid models were used and statistically compared. The outcomes compared between techniques included procedural time, difference in guide-pin start point, difference in version and inclination, and surgeon confidence via a confidence rating scale. Results When comparing traditional preoperative software planning to MR visualization as techniques to assist surgeons in glenoid guide pin insertion, there were no statistically significant differences in terms of mean procedure time (P=0.634), glenoid start-point (TSP=2.2±0.2 mm, MR=2.1±0.1 mm; P=0.760), guide-pin orientation (P=0.586), or confidence rating score (P=0.850). Conclusions The results demonstrate that there were no significant differences between traditional preoperative software planning and MR visualization for guide-pin placement into models of eroded glenoids. A perceived benefit of MR is the real-time intraoperative visibility of the surgical plan and the patient’s anatomy; however, this did not translate into decreased procedural time or improved guide-pin position. Level of evidence Basic science study, biomechanics
Impact of structural modifications of IgG antibodies on effector functions
Immunoglobulin G (IgG) antibodies are a critical component of the adaptive immune system, binding to and neutralizing pathogens and other foreign substances. Recent advances in molecular antibody biology and structural protein engineering enabled the modification of IgG antibodies to enhance their therapeutic potential. This review summarizes recent progress in both natural and engineered structural modifications of IgG antibodies, including allotypic variation, glycosylation, Fc engineering, and Fc gamma receptor binding optimization. We discuss the functional consequences of these modifications to highlight their potential for therapeutical applications
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