Exposure assessment of process-related contaminants in food by biomarker monitoring

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario’s and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment

The influence of alendronate on osseointegration of nanotreated dental implants in New Zealand rabbits

Objectives: Growing clinical demands for stronger and faster bone bonding to the implant have motivated the development of methods enhancing osseointegration. Lately, the application of bisphosphonates (bis) in order to optimize bone healing has become a topic of great interest. N-containing bis, such as alendronate (ALN), are the more potent drugs of this class. It was the aim of this study to determine the effect of ALN on the osseointegration of a well-documented nanotreated implant system in a rabbit femoral condyle model. Material and methods: Thirty-two adult female New Zealand White rabbits received one implant (3.25mm in diameter and 10mm in length) in their left femoral condyle, a week after they were ovariectomized. Half of them were saline treated (control, group A) and the other half were ALN treated (group B). Rabbits from both groups were euthanized after 6 and 12 weeks, respectively. Results: The specimens were evaluated histologically and histomorphometrically. Upon histological evaluation, no obvious differences were found between the control and the treatment group. Implants showed good integration into the bone tissue surrounding them. There were also no statistically significant differences in bone-to-implant contact and the amount of bone tissue in the immediate neighborhood of the implant at both healing periods. Conclusions: The systemic administration of ALN was not found to affect histological osseointegration of implants in animals with a hormonal status resembling that of postmenopausal healthy women. Further research will be needed to investigate this approach. © 2011 John Wiley & Sons A/S

Implant survival and complications

OBJECTIVES: The task of this working group was to analyze biological, technical and aesthetic complications of single crowns on implants and fixed dental prostheses with or without cantilevers on implants over 5 years or more. In addition, the group analyzed economic aspects on such implant treatment. MATERIALS AND METHODS: A systematic search of the relevant literature was conducted and critically reviewed. Four manuscripts were presented to cover the topics. RESULTS: The consensus statements prepared by the group and later accepted at the plenary session as well as suggestions for future research are presented in this article. The four reviews by Jung et al., Pjetursson et al., Romeo and Storelli and Scheuber et al. are printed separately and present detailed analyses of the research topics.The 3rd EAO Consensus Conference, Pfäffikon, Schwyz, Switzerland, 15–18 February 2012. In Clinical Oral Implants Research, 2012, v. 23 n. S6, p. 63-6

Collaborative open science as a way to reproducibility and new insights in primate cognition research

Inferring the evolutionary history of cognitive abilities requires large and diverse samples. However, such samples are often beyond the reach of individual researchers or institutions, and studies are often limited to small numbers of species. Consequently, methodological and site-specific-differences across studies can limit comparisons between species. Here we introduce the ManyPrimates project, which addresses these challenges by providing a large-scale collaborative framework for comparative studies in primate cognition. To demonstrate the viability of the project we conducted a case study of short-term memory. In this initial study, we were able to include 176 individuals from 12 primate species housed at 11 sites across Africa, Asia, North America and Europe. All subjects were tested in a delayed-response task using consistent methodology across sites. Individuals could access food rewards by remembering the position of the hidden reward after a 0, 15, or 30-second delay. Overall, individuals performed better with shorter delays, as predicted by previous studies. Phylogenetic analysis revealed a strong phylogenetic signal for short-term memory. Although, with only 12 species, the validity of this analysis is limited, our initial results demonstrate the feasibility of a large, collaborative open-science project. We present the ManyPrimates project as an exciting opportunity to address open questions in primate cognition and behaviour with large, diverse datasets