Pieter De Pauw

Functional β-Cell Mass and Insulin Sensitivity Is Decreased in Insulin-Independent Pancreas-Kidney Recipients

Background. To compare functional &bgr;-cell mass and insulin sensitivity in insulin-independent pancreas-kidney recipients with that in age- and body mass index-matched nondiabetic kidney recipients and normal controls. Methods. All transplant recipients were on maintenance immunosuppression with mycophenolate mofetil and tacrolimus since more than 2.7 years (2.2–3.8 years). Their C-peptide release was measured during a 170-min hyperglycemic clamp, first in absence and then in presence of glucagon. Data were compared with those after glucose stimulation alone. Insulin sensitivity under basal and stimulated conditions was calculated using homeostasis model assessment of insulin resistance and insulin sensitivity index, respectively. Results. Functional &bgr;-cell mass in pancreas-kidney recipients with systemic venous drainage was reduced, representing, respectively, 63% and 80% of that in healthy controls and kidney recipients. Pancreas-kidney recipients exhibited lower insulin sensitivity than healthy controls (homeostasis model assessment of insulin resistance was 0.8, 0.7–1.1 vs. 0.4, 0.3–0.8; P=0.02 and insulin sensitivity index was 17, 12–24 mg/kg/min per 100 &mgr;U/mL vs. 31, 20–38 mg/kg/min per 100 &mgr;U/mL; P=0.04). Conclusions. Using a hyperglycemic clamp, the functional &bgr;-cell mass in insulin-independent pancreas-kidney recipients was found to be 37% and 20% lower than in healthy controls and nondiabetic kidney recipients.

Shedding New Light on How Advertising Literacy Can Affect Children's Processing of Embedded Advertising Formats: A Future Research Agenda

Advertisers are continuously searching for new ways to persuade children; current methods include fully integrating commercial content into media content, actively engaging children with the commercial content, and increasing the number of commercial messages children are confronted with at one moment in time. This poses a challenge for how children cope with embedded advertising. This conceptual article aims to develop a theoretically grounded framework for investigating how children process embedded advertising. More precisely, it sheds light on previous research and conceptualizations of advertising literacy and provides suggestions for future research. The article examines conceptual and methodological issues and discusses the need for research on how to improve childrens coping with embedded advertising by emphasizing the value of persuasive intent priming and implementation intentions. To conclude, future research directions are discussed regarding strategies to strengthen childrens coping skills and their dispositional (i.e., associative network consisting of cognitive, moral, and affective beliefs related to advertising) and situational (i.e., actual recognition of and critical reflection on advertising) advertising literacy.

Development of a multipurpose time-resolved fluorescence immunoassay for rat insulin

We present a time-resolved fluorescence immunoassay (TR-FIA) for the measurement of rat insulin in cell extracts and culture media. This assay is based on the binding of two monoclonal antibodies to different parts of the insulin molecule in a 96-well microtiter plate. For the detection, europium-labeled streptavidin that interacts with the second biotinylated antibody is used. Samples of 25 microl could be analyzed in less than 2 days with a measuring range between 5 and 1250 pg (0.2-50 microg/L or 34.4-8600 pM). The inter- and intraassay percentage coefficients of variation were less than 8.3 and 5.1, respectively. Recoveries of 0.48 to 40 microg/L rat insulin, added to culture medium, ranged between 94 and 107%. Results were significantly correlated with those of an in-house radioimmunoassay (RIA) for rodent insulin (P<0.0001, r(2)=0.99). The TR-FIA method had a similar detection limit (0.16 microg/L), but its working range was at least 5-fold larger. Additional advantages include the lower cost, the applicability to measurements in tissue and serum, and the quantification of insulin from other species.

Disclosing Brand Placement to Young Children

ABSTRACT In spite of the EUs prohibition on brand placement in childrens programmes, it is argued that children may still be exposed to this advertising format in many occasions. Consequently, and as children may have even more difficulties than adults to distinguish the commercial content from the editorial media content in which it is embedded, an advertising disclosure may be necessary to enable them to cope with brand placement. Entailing two one-factorial between-subjects experiments, the current article examined how different types of brand placement warning cues influenced cognitive advertising literacy and the attitude toward the placed brand, among children between 8 and 10 years old. In a first study, it was investigated how these outcomes were influenced by warning cues with different perceptual modalities (no vs. auditory vs. visual cue, N = 98). The results showed that a visual warning cue was more effective than an auditory warning cue (vs. no warning cue) in addressing cognitive advertising literacy. However, this higher cognitive advertising literacy could not account for the effect of the visual warning cue on brand attitude. In a second study, it was examined whether the effectiveness of this visual warning cue was influenced by the timing of disclosure (cue prior to vs. during media containing brand placement, N = 142). Additionally, it was tested whether the effect of the cue on brand attitude could be explained by cognitive advertising literacy if childrens sceptical attitude toward the brand placement format was taken into account. The results showed that cognitive advertising literacy was higher when the cue was shown prior to than during the media content. This cue-influenced cognitive advertising literacy resulted in a more positive brand attitude, but only among children who were less sceptical toward brand placement. This positive relation disappeared among moderately and highly sceptical children. These findings have significant theoretical, practical and social implications.

Prediction of Impending Type 1 Diabetes through Automated Dual-Label Measurement of Proinsulin:C-Peptide Ratio

Background The hyperglycemic clamp test, the gold standard of beta cell function, predicts impending type 1 diabetes in islet autoantibody-positive individuals, but the latter may benefit from less invasive function tests such as the proinsulin:C-peptide ratio (PI:C). The present study aims to optimize precision of PI:C measurements by automating a dual-label trefoil-type time-resolved fluorescence immunoassay (TT-TRFIA), and to compare its diagnostic performance for predicting type 1 diabetes with that of clamp-derived C-peptide release. Methods Between-day imprecision (n = 20) and split-sample analysis (n = 95) were used to compare TT-TRFIA (AutoDelfia, Perkin-Elmer) with separate methods for proinsulin (in-house TRFIA) and C-peptide (Elecsys, Roche). High-risk multiple autoantibody-positive first-degree relatives (n = 49; age 5–39) were tested for fasting PI:C, HOMA2-IR and hyperglycemic clamp and followed for 20–57 months (interquartile range). Results TT-TRFIA values for proinsulin, C-peptide and PI:C correlated significantly (r2 = 0.96–0.99; P<0.001) with results obtained with separate methods. TT-TRFIA achieved better between-day %CV for PI:C at three different levels (4.5–7.1 vs 6.7–9.5 for separate methods). In high-risk relatives fasting PI:C was significantly and inversely correlated (rs = -0.596; P<0.001) with first-phase C-peptide release during clamp (also with second phase release, only available for age 12–39 years; n = 31), but only after normalization for HOMA2-IR. In ROC- and Cox regression analysis, HOMA2-IR-corrected PI:C predicted 2-year progression to diabetes equally well as clamp-derived C-peptide release. Conclusions The reproducibility of PI:C benefits from the automated simultaneous determination of both hormones. HOMA2-IR-corrected PI:C may serve as a minimally invasive alternative to the more tedious hyperglycemic clamp test.

From persuasive messages to tactics: Exploring children’s knowledge and judgement of new advertising formats:

Despite that contemporary advertising is decreasingly about persuading children through persuasive messages and increasingly about influencing them through implicit tactics, little attention has been given to how children may cope with advertising by understanding and evaluating the new advertising tactics. Drawing on 12 focus groups entailing 60 children of ages 9–11 years, this article investigates children’s advertising literacy by exploring their knowledge and judgements (and accordingly reasoning strategies) of the new advertising formats. In particular, insight is provided into children’s critical reflection on the tactics of brand integration, interactivity and personalization in the advertising formats brand placement, advergames and retargeted pre-roll video ads on social media. It is shown that while children not spontaneously do so, they appear to have the ability to understand these tactics and form judgements about their (moral) appropriateness, thereby considering a wide range of societal actors.

Considering Children’s Advertising Literacy From a Methodological Point of View: Past Practices and Future Recommendations

Abstract Children’s advertising literacy is a well-documented research area. Yet the literature on how to measure advertising literacy is not straightforward due to conceptual and operational differences in the existing studies. This has led to inconsistent results with regard to the development, possession, and application of advertising literacy. The aim of this article is to give an overview of the different measurement methodologies used in past research efforts to assess children’s advertising literacy. Taking into account children’s psychological development (cognitive, affective, and moral), we formulate recommendations on which methods are most suitable to use in future advertising literacy research among different age categories.

Taking children's advertising literacy to a higher level: A multilevel analysis exploring the influence of parents, peers, and teachers

Few studies focus on how children’s environment affects their ability to cope with contemporary advertising. This study uses multilevel analysis techniques to explore how parents’, classmates’, and teachers’ characteristics influence primary school children’s dispositional advertising literacy, while acknowledging these children’s own individual features. To this end, three surveys were conducted, resulting in four data sets linking information obtained from 9- to 12-year-old children (n = 392), their peer group (children aggregated per class; n = 22), their parents (n = 191), and their teachers (n = 22). The results show that children’s cognitive and attitudinal advertising literacy is to a large extent (12%-13%) determined by class-level processes (especially peers). Children’s moral advertising literacy is primarily an individual matter (1%), albeit greatly influenced by their teachers. In general, parents’ impact is mainly expressed through socioeconomic factors.