Naar een duurzamere voedselmarkt : De dynamiek van vraag en aanbod

Een kennisarena is een platform waarin bedrijfsleven, maatschappelijke organisaties, overheid en kennisinstellingen met elkaar de kennisbehoefte rondom een thema bespreken. Er is voor de Kennisarena Voeding gekozen voor vier deelonderwerpen: consumentengedrag en duurzaamheid; verduurzaming van het aanbod; transparantie in de keten; voedselverspilling. De stand van zaken t.a.v. deze vier onderwerpen is in dit rapport in kaart gebrach

Permeability and modulation of the intestinal epithelial barrier in vitro

The bioavailability of all ingested compounds is to a great extend determined by the ability of these compounds to pass the intestinal epithelium. A high bioavailability is guaranteed for most nutrients and electrolytes since they are actively absorbed by the epithelium. The same epithelium, however, renders the entrance of non-nutrient (potentially harmful) hydrophilic (macro-) molecules, viruses and bacteria into the systemic circulation very low by presenting an almost impermeable barrier to these agent. The functional and structural properties of the single cell layer forming the intestinal epithelium determine the transepithelial permeability, which is an important factor in determining the bioavailability of all ingested compounds. Thus, insight in this transepithelial permeability is of considerable interest. However, the complexity of the gastrointestinal tract, and of the pre-and post-absorptive kinetics hampered the collection of accurate data. Therefore, a simple, accurate, reproducible, and cheap in vitro model was needed to screen the vast amount of newly developed, or discovered compounds for their intestinal transepithelial permeation.One very popular model consists of the human colonic carcinoma cell line Caco-2 grown in a two-compartment system. Transport experiments with this Caco-2 system yielded in vitro permeation rates which allowed prediction of the oral bioavailability in humans for many different compounds. However, it is generally assumed that the Caco-2 cells restrict the paracellular permeation (extracellular passage along the cells) of hydrophilic compounds such as intact peptides to a greater extent than the small intestinal epithelium in vivo . Thus especially for the modeling of hydrophilic macromolecular permeation, an additional model would be of great value. We posed the question whether the small intestinal epithelium derived cell line IEC-18 could be that model. We found that whereas the Caco-2 cells presented a good model for a general screen on intestinal permeation for a wide variety of compounds, the IEC-18 cells did allow for a better discrimination between the hydrophilic compounds on the basis of their molecular weight. Consequently, experiments with the filter grown IEC-18 cells yielded discriminative permeation rates for the paracellular permeation of hydrophilic compounds with differing bioavailabilities. Thus, data presented in this thesis suggest that the filter grown IEC-18 cells could be valuable as model for paracellular permeability in the small intestine.However, the cell morphology and brush border enzyme activities of IEC-18 cells cultured under standard conditions showed that the cells obtained only a low status of differentiation, while addition of dexamethasone to the culture medium triggered the cells to acquire a more enterocyte-like phenotype. Concomitant with the morphological changes, a tightening of the paracellular barrier was found which suggests that IEC-18 cells might present a model to study the effects of intestinal epithelial cell differentiation on paracellular permeability development along the intestinal crypt-villus axis.Additionally, since it has been recognized that the intestinal epithelial barrier can be compromised by compounds such as drug absorption enhancers or ingested toxins, we studied the effects of a proposed drug absorption enhancer (palmitoyl carnitine) and the bio-active heavy metal cadmium, on structural and functional features of the two intestinal cell lines. We concluded that for studies to modulation of intestinal epithelial barrier function, the Caco-2 is a more convenient model than the IEC-18 cells due to the high basal barrier function for hydrophilic molecules of the Caco-2 cells relative to the low barrier function of IEC-18 cells. The occurrence of increased hydrophilic macromolecular permeability concomitant with membrane damage but without concurrent alterations in the expression of the tight junctional protein ZO-1, as was found after palmitoyl carnitine exposure, strongly suggests the enhancement of transcellular permeability. On the other hand, increased hydrophilic macromolecular permeability and a decreased transepithelial electrical resistance, concomitant with alterations in junctional ZO-1 expression, but without concurrent membrane damage, as was found after cadmium exposure, strongly suggests the enhancement of the paracellular pathway.In conclusion, the two intestinal cell lines Caco-2 and IEC-18, together, offer the possibility to obtain in vitro permeation rates, enabling bioavailability modeling for virtually all classes of compounds. Furthermore, the in vitro systems and research strategies presented in this thesis might help to elucidate modes of action of newly developed compounds on the barrier function of the intestinal mucosa and might thus help to assess the effectivity and safety of absorption enhancers, and to indicate mucosal toxicity of orally ingested compounds such as drugs or food related products.</p

Gastroenteritis Caused by Norovirus GGII.4, the Netherlands, 1994–2005

From 1994 through 2005, gastroenteritis outbreaks caused by norovirus generally increased in the Netherlands, with 3 epidemic seasons associated with new GGII.4 strains. Increased percentages of GGII.4 strains during these epidemics, followed by a sharp decrease in their absolute and relative numbers, suggest development of immunity

Листи Г.П. Житецького: з епістолярної спадщини О.М. Лазаревського

В статье исследуются и публикуются письма филолога и украинского деятеля культуры И.П. Житецкого к известному историку и археографу А.М. Лазаревскому. Во вступительной статье, письмах и комментариях к ним сообщается о малоизвестных страницах жизни и деятельности представителей разных генераций украинских и российских деятелей культуры. Автор писем сообщает о подготовке и публикации научных работ, поисках источников, делится своими творческими планами. В письмах освещены события общественно-политической и культурной жизни Российской империи и Украины конца ХIХ и начала ХХ вв.The article contains the letters of I. Zhytetsky, a Ukrainian philologist and cultural worker, to A. Lazarevsky, a noted historian and archeographer. The Introduction, letters and comments cover little-known information about life and work of different Ukrainian and Russian cultural workers. The letters shed light on social, political and cultural life of the Russian Empire and Ukraine of late XIX – early XX centuries

The Role of Microbiota-Derived Metabolites in Colorectal Cancer

The impact of bacterial members of the microbiota on the development of colorectal cancer (CRC) has become clear in recent years. However, exactly how bacteria contribute to the development of cancer is often still up for debate. The impact of bacteria-derived metabolites, which can influence the development of CRC either in a promoting or inhibiting manner, is undeniable. Here, we discuss the effects of the most well-studied bacteria-derived metabolites associated with CRC, including secondary bile acids, short-chain fatty acids, trimethylamine-N-oxide and indoles. We show that the effects of individual metabolites on CRC development are often nuanced and dose- and location-dependent. In the coming years, the array of metabolites involved in CRC development will undoubtedly increase further, which will emphasize the need to focus on causation and mechanisms and the clearly defined roles of bacterial species within the microbiota

Enhanced Hygiene Measures and Norovirus Transmission during an Outbreak

Enhanced hygiene measures can reduce norovirus transmission potential by 85%

Talking about torque : measuring pack accessibility - a review

Vacuum lug closures are a simple, reliable and low-cost packaging option used for the protection and promotion of jams, pickles and sauces. Several surveys and anecdotal evidence suggest that packaging of this type can be notoriously difficult to open. Given the difficulty that packaging of this type may pose, there has been significant academic research in understanding the difficulties associated with accessing packaging of this type. In response to the qualitative data gathered in these surveys, research teams have attempted to quantify the forces that users can apply. What emerges from the approaches taken is a complex picture. Researchers do make comparisons with previous work, but numbers of people tested, materials used, diameter and posture differ between research groups as does the information and style of the dissemination of results. Future packaging research experimental design should be more thorough and consistent in the sampling and presentation of data to facilitate repeatability and validity and enable the data gathered to form a larger data set. Further, to create usable 'design limits' for manufacturers and designers to reduce the variability within the data set, more focused measurements should be taken on distinct user groups such as a specific female decile and subgroup, i.e. small-handed women between 70 and 80. Working with distinct populations would enable the likelihood of design changes to packaging to be readily compared and assessed

Different virucidal activities of hyperbranched quaternary ammonium coatings on poliovirus and influenza virus

Virucidal activity of immobilized quaternary ammonium compounds (IQACs) coated onto glass and plastic surfaces was tested against enveloped influenza A (H1N1) virus and nonenveloped poliovirus Sabin1. The IQACs tested were virucidal against the influenza virus within 2 min, but no virucidal effect against poliovirus was found in 6 h

Sweet Temptations:How Does Reading a Fotonovela About Diabetes Affect Dutch Adults with Different Levels of Literacy?

Recent studies suggest that health-related fotonovelas-booklets that portray a dramatic story using photographs and captions-may be effective health communication tools, especially for readers with a low level of literacy. In this experiment, effects on knowledge and behavioral intentions were assessed of a fotonovela originally developed for a Latin-American audience. Dutch readers from a low literacy group (N = 89) and a high literacy group (N = 113) were randomly assigned to one of three conditions: a fotonovela condition (all captions translated into Dutch), a traditional brochure condition (also in Dutch), and a control condition. On knowledge about diabetes, participants in the fotonovela condition outperformed participants in both other conditions. This finding was consistent across literacy levels. On behavioral intentions, however, readers of the fotonovela did not score significantly higher than participants in the other conditions. We also evaluated hypotheses proposed in the Entertainment Overcoming Resistance Model (EORM; Moyer-Guse, 2008) on the possible mechanisms underlying persuasion through narratives. No support was found for the mechanisms proposed in the EORM. The outcomes of this study suggest that a fotonovela may be a valuable health education format for adults with varying levels of literacy, even if it was developed for a target group with a different cultural background.</p