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Kinetics of Physiological Responses as a Measure of Intensity and Hydration Status During Experimental Physical Stress in Human Volunteers

Kartaram, S.W. (author), van Norren, K. (author), Schoen, E. (author), Teunis, M. (author), Mensink, M. (author), Verschuren, M. (author), M’Rabet, L. (author), Besseling-van der Vaart, I. (author), Mohrmann, K. (author), Wittink, H. (author), Garssen, J. (author), Witkamp, R. (author), Pieters, R. (author)

Introduction: Strenuous physical stress induces a range of physiological responses, the extent depending, among others, on the nature and severity of the exercise, a person’s training level and overall physical resilience. This principle can also be used in an experimental set-up by measuring time-dependent changes in biomarkers for...

article 2020

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Plasma citrulline concentration a marker for intestinal functionality reflects exercise intensity in healthy young men

Kartaram, S. (author), Mensink, M. (author), Teunis, M. (author), Schoen, E. (author), Witte, G. (author), Janssen Duijghuijsen, L. (author), Verschuren, M. (author), Mohrmann, K. (author), M'Rabet, L. (author), Knipping, K. (author), Wittink, H. (author), van Helvoort, A. (author), Garssen, J. (author), Witkamp, R. (author), Pieters, R. (author), van Norren, K. (author)

Background & aims: Plasma citrulline concentration is considered to be a marker for enterocyte metabolic mass and to reflect its reduction as may occur during intestinal dysfunction. Strenuous exercise can act as a stressor to induce small intestinal injury. Our previous studies suggest that this comprises the intestinal ability to produce...

article 2019

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Release of major peanut allergens from their matrix under various pH and simulated saliva conditions—Ara h2 and ara h6 are readily bio-accessible

Koppelman, S.J. (author), Smits, M. (author), Tomassen, M. (author), de Jong, G.A.H. (author), Baumert, J. (author), Taylor, S.L. (author), Witkamp, R. (author), Veldman, R.J. (author), Pieters, R. (author), Wichers, H. (author)

The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were...

article 2018

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Current challenges facing the assessment of the allergenic capacity of food allergens in animal models

Bøgh, K.L. (author), van Bilsen, J. (author), Głogowski, R. (author), López-Expósito, I. (author), Bouchaud, G. (author), Blanchard, C. (author), Bodinier, M. (author), Smit, J. (author), Pieters, R. (author), Bastiaan-Net, S. (author), de Wit, N. (author), Untersmayr, E. (author), Adel-Patient, K. (author), Knippels, L. (author), Epstein, M.M. (author), Noti, M. (author), Nygaard, U.C. (author), Kimber, I. (author), Verhoeckx, K. (author), O'Mahony, L. (author)

Food allergy is a major health problem of increasing concern. The insufficiency of protein sources for human nutrition in a world with a growing population is also a significant problem. The introduction of new protein sources into the diet, such as newly developed innovative foods or foods produced using new technologies and production...

article 2016

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International ring trial of the epidermal equivalent sensitizer potency assay: Reproducibility and predictive-capacity

Teunis, M.A.T. (author), Spiekstra, S.W. (author), Smits, M. (author), Adriaens, E. (author), Eltze, T. (author), Galbiati, V. (author), Krul, C.A.M. (author), Landsiedel, R. (author), Pieters, R. (author), Reinders, J. (author), Roggen, E. (author), Corsini, E. (author), Gibbs, S. (author)

This study describes the international ring trial of the epidermal-equivalent (EE) sensitizer potency assay. This assay does not distinguish a sensitizer from a non-sensitizer, but may classify known skin sensitizers according to their potency. It assesses the chemical concentration resulting in 50% cytotoxicity (EE-EC50) or the 2-fold increase...

article 2014

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Transfer of a two-tiered keratinocyte assay: IL-18 production by NCTC2544 to determine the skin sensitizing capacity and epidermal equivalent assay to determine sensitizer potency

Teunis, M. (author), Corsini, E. (author), Smits, M. (author), Madsen, C.B. (author), Eltze, T. (author), Ezendam, J. (author), Galbiati, V. (author), Gremmer, E. (author), Krul, C.A.M. (author), Landin, A. (author), Landsiedel, R. (author), Pieters, R. (author), Rasmussen, T.F. (author), Reinders, J. (author), Roggen, E. (author), Spiekstra, S. (author), Gibbs, S. (author)

At present, the identification of potentially sensitizing chemicals is carried out using animal models. However, it is very important from ethical, safety and economic point of view to have biological markers to discriminate allergy and irritation events, and to be able to classify sensitizers according to their potency, without the use of...

article 2013

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Respiratory sensitization: Advances in assessing the risk of respiratory inflammation and irritation

Vandebriel, R. (author), Callant Cransveld, C. (author), Crommelin, D. (author), Diamant, Z. (author), Glazenburg, B. (author), Joos, G. (author), Kuper, F. (author), Natsch, A. (author), Nijkamp, F. (author), Noteborn, H. (author), Pieters, R. (author), Roberts, D. (author), Roggen, E. (author), Rorije, E. (author), Seed, M. (author), Sewald, K. (author), van den Heuvel, R. (author), van Engelen, J. (author), Verstraelen, S. (author), van Loveren, H. (author)

Respiratory sensitization provides a case study for a new approach to chemical safety evaluation, as the prevalence of respiratory sensitization has increased considerably over the last decades, but animal and/or human experimental/predictive models are not currently available. Therefore, the goal of a working group was to design a road map to...

article 2011

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Lactobacillus casei Shirota does not decrease the food allergic response to peanut extract in Brown Norway rats

de Jonge, J.D. (author), Ezendam, J. (author), Knippels, L.M.J. (author), Penninks, A.H. (author), Pieters, R. (author), van Loveren, H. (author), TNO Kwaliteit van Leven (author)

Probiotics are claimed to beneficially affect the immune system and their involvement in allergy prevention is being investigated extensively. However, the efficacy of probiotics in allergy prevention remains controversial. We investigated whether the probiotic Lactobacillus casei Shirota (LcS) could modulate the food allergic response against...

article 2008

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Never Eat In That Restaurant, I Did!: Exploring why people engage in negative word-of-mouth communication

Wetzer, I.M. (author), Zeelenberg, M. (author), Pieters, R. (author), TNO Defensie en Veiligheid (author)

What do consumers want to achieve when they engage in negative word-of-mouth communication (N-WOM)? Two studies explore this question and reveal that consumers pursue specific goals when engaging in N-WOM and that these goals systematically differ between the specific negative emotions that are experienced. For example, the results reveal that...

article 2007

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The CD28/CTLA-4-B7 signaling pathway is involved in both allergic sensitization and tolerance induction to orally administered peanut proteins

van Wijk, F. (author), Nierkens, S. (author), de Jong, W. (author), Wehrens, E.J.M. (author), Boon, L. (author), van Kooten, P. (author), Knippels, L.M.J. (author), Pieters, R. (author), TNO Kwaliteit van Leven (author)

Dendritic cells are believed to play an essential role in regulating the balance between immunogenic and tolerogenic responses to mucosal Ags by controlling T cell differentiation and activation via costimulatory and coinhibitory signals. The CD28/CTLA-4-CD80/CD86 signaling pathway appears to be one of the most important regulators of T cell...

article 2007

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Bis(tributyltin)oxide (TBTO) decreases the food allergic response against peanut and ovalbumin in Brown Norway rats

de Jonge, J.D. (author), Ezendam, J. (author), Knippels, L.M.J. (author), Odink, J. (author), Pourier, M.S. (author), Penninks, A.H. (author), Pieters, R. (author), van Loveren, H. (author), TNO Kwaliteit van Leven (author)

Other factors than the allergen itself may be of importance in the development of food allergy. This report describes the influence of the immunosuppressive compound bis(tributyltin)oxide (TBTO), present in the food chain, on the development of food allergy to peanut or ovalbumin in Brown Norway (BN) rats. To study these effects BN rats were...

article 2007

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CD4+CD25+ T cells regulate the intensity of hypersensitivity responses to peanut, but are not decisive in the induction of oral sensitization

van Wijk, F. (author), Wehrens, E.J.M. (author), Nierkens, S. (author), Boon, L. (author), Kasran, A. (author), Pieters, R. (author), Knippels, L.M.J. (author), TNO Kwaliteit van Leven (author)

Background: Naturally occurring CD4+CD25+ regulatory T cells (Tregs) play a critical role in the maintenance of self-tolerance and it has been suggested that these Tregs may also be involved in preventing allergic disease. Objective: The precise role of CD4+CD25+ T cells in the regulation of allergic responses to mucosal antigens remains to be...

article 2007

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The effect of the food matrix on In Vivo immune responses to purified peanut allergens

van Wijk, F. (author), Nierkens, S. (author), Hassing, I. (author), Feijen, M. (author), Koppelman, S.J. (author), de Jong, G.A.H. (author), Pieters, R. (author), Knippels, L.M.J. (author), TNO Kwaliteit van Leven (author)

There is little knowledge about the factors that determine the allergenicity of food proteins. One aspect that remains to be elucidated is the effect of the food matrix on immune responses to food proteins. To study the intrinsic immunogenicity of allergens and the influence of the food matrix, purified peanut allergens (Ara h 1, Ara h 2, Ara h...

article 2005

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CTLA-4 signaling regulates the intensity of hypersensitivity responses to food antigens, but is not decisive in the induction of sensitization

van Wijk, F. (author), Hoeks, S. (author), Nierkens, S. (author), Koppelman, S.J. (author), van Kooten, P. (author), Boon, L. (author), Knippels, L.M.J. (author), Pieters, R. (author), TNO Kwaliteit van Leven (author)

Although food allergy has emerged as a major health problem, the mechanisms that are decisive in the development of sensitization to dietary Ag remain largely unknown. CTLA-4 signaling negatively regulates immune activation, and may play a crucial role in preventing induction and/or progression of sensitization to food Ag. To elucidate the role...

article 2005

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Mixed antibody and T cell responses to peanut and the peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 in an oral sensitization model

van Wijk, F. (author), Hartgring, S. (author), Koppelman, S.J. (author), Pieters, R. (author), Knippels, L.M.J. (author), TNO Voeding (author)

Background: Peanut allergy is known for its severity and persistence through life. Several peanut proteins have been identified as allergenic and are indicated as Ara h 1-7. Very little is known about the mechanisms that underlie sensitization to peanut proteins. Objective: The purpose of the present study was to reveal the immune responses that...

article 2004

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Organotin-induced apoptosis occurs in small CD4+CD8+ thymocytes and is accompanied by an increase in RNA systhesis

Gennari, A. (author), Bol, M. (author), Seinen, W. (author), Penninks, A. (author), Pieters, R. (author), TNO Voeding (author)

article 2002

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Organotin-induced apoptosis occurs in small CD4+CD8+ thymocytes and is accompanied by an increase in RNA synthesis

Centraal Instituut voor Voedingsonderzoek TNO (author), Gennari, A. (author), Bol, M. (author), Seinen, W. (author), Penninks, A. (author), Pieters, R. (author)

The organotin compounds di-n-butyltin dichloride (DBTC) and tri-n-butyltin chloride (TBTC) induce thymus atrophy in rats. At low doses they inhibit immature thymocyte proliferation, whereas at higher doses in particular TBTC induces apoptotic cell death. In vitro, a similar concentration-effect relationship was observed, i.e. low concentrations...

article 2002

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Coadministration of antigen and particles optimally stimulates the immune response in an intranasal administration model in mice

van Zijverden, M. (author), de Haar, C. (author), van Beelen, A. (author), van Loveren, H. (author), Penninks, A. (author), Pieters, R. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Some particulate matter is known to affect human health, yet the mechanism(s) by which it acts is largely unknown. One of the factors that may play a role in the immune- stimulating activity of particles is binding of allergen to particles. This may turn the particles into allergen carriers, resulting in antigen deposition within the altered...

article 2001

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Diesel exhaust, carbon black and silica particles display distinct Th1/Th2 modulating activity

van Zijverden, M. (author), van der Pijl, A. (author), Bol, M. (author), van Pinxteren, F.A. (author), de Haar, C. (author), Penninks, A.H. (author), van Loveren, H. (author), Pieters, R. (author)

article 2000