Tim van Zutphen

Dr. Tim van Zutphen


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
4 January 2010 in BMC Genomics
Verified
Journal Article
Open access
PDF file
TZTim van Zutphen
Tim van Zutphen
RBRichard Js Baerends
Richard Js Baerends
KSKim A Susanna
Kim A Susanna
AJAnne de Jong
Anne de Jong
OKOscar Kuipers
Oscar Kuipers
IKIda J. Van der Klei
Ida J. Van der Klei
Background: Methylotrophic yeast species (e.g. Hansenula polymorpha, Pichia pastoris) can grow on methanol as sole source of carbon and energy. These organisms are important cell factories for the production of recombinant proteins, but are also used in fundamental research as model organisms to study peroxisome biology. During exponential growth on glucose, cells of H. polymorpha typically contain a single, small peroxisome that is redundant for growth while on methanol multiple, enlarged peroxisomes are present. These organelles are crucial to support growth on methanol, as they contain key enzymes of methanol metabolism. In this study, changes in the transcriptional profiles during adaptation of H. polymorpha cells from glucose- to methanol-containing media were investigated using DNA-microarray analyses. Results: Two hours after the shift of cells from glucose to methanol nearly 20% (1184 genes) of the approximately 6000 annotated H. polymorpha genes were significantly upregulated with at least a two-fold differential expression. Highest upregulation (> 300-fold) was observed for the genes encoding the transcription factor Mpp1 and formate dehydrogenase, an enzyme of the methanol dissimilation pathway. Upregulated genes also included genes encoding other enzymes of methanol metabolism as well as of peroxisomal ?-oxidation. A moderate increase in transcriptional levels (up to 4-fold) was observed for several PEX genes, which are involved in peroxisome biogenesis. Only PEX11 and PEX32 were higher upregulated. In addition, an increase was observed in expression of the several ATG genes, which encode proteins involved in autophagy and autophagy processes. The strongest upregulation was observed for ATG8 and ATG11. Approximately 20% (1246 genes) of the genes were downregulated. These included glycolytic genes as well as genes involved in transcription and translation. Conclusion: Transcriptional profiling of H. polymorpha cells shifted from glucose to methanol showed the expected downregulation of glycolytic genes together with upregulation of the methanol utilisation pathway. This serves as a confirmation and validation of the array data obtained. Consistent with this, also various PEX genes were upregulated. The strong upregulation of ATG genes is possibly due to induction of autophagy processes related to remodeling of the cell architecture required to support growth on methanol. These processes may also be responsible for the enhanced peroxisomal ?-oxidation, as autophagy leads to recycling of membrane lipids. The prominent downregulation of transcription and translation may be explained by the reduced growth rate on methanol (td glucose 1 h vs td methanol 4.5 h).

4 February 2023 in European Journal of Nutrition
Verified
Journal Article
Open access
PDF file
EVEdith Visser
Edith Visser
KJKim de Jong
Kim de Jong
JPJanneke J. S. Pepels
Janneke J. S. Pepels
HKHuib Kerstjens
Huib Kerstjens
ABAnneke Ten Brinke
Anneke Ten Brinke
TZTim van Zutphen
Tim van Zutphen
Purpose: Dietary factors have been suggested as drivers of the rising prevalence of adult-onset asthma, but evidence is inconclusive, possibly due to the complex interrelation with obesity. We aim to explore the relation of diet quality and food intake with incident adult-onset asthma in normal weight and overweight adults of the prospective population-based Lifelines Cohort Study. Methods: Incident adult-onset asthma was defined as self-reported asthma at ± 4-year follow-up, in adults free of airway disease at baseline. Diet quality scores and food group intake were assessed at baseline. Log-binomial regression analyses were used to estimate adjusted relative risks (RR) between dietary intake (per portion) and incident adult-onset asthma, in categories of BMI (cutoff: 25 kg/m2). Results: 477 incident asthma cases (75% female, 62% overweight) and 34,698 controls (60% female, 53% overweight) were identified. Diet quality—assessed by the Lifelines Diet Score and Mediterranean Diet Score—was not associated with incident adult-onset asthma in the two BMI groups. Although the dietary intake of several food groups differed between cases and controls, after adjustment for confounders only few remained associated with adult-onset asthma, including red and processed meat (RR: 0.93 per 15 g intake; 95% CI 0.86–0.99) in the normal weight group and intake of cheese (RR 1.09 per 20 g intake; 95% CI 1.00–1.17) and vegetables (RR 1.10 per 50 g intake; 95% CI 1.00–1.21) in the overweight group. Conclusion: The results of this study question the role of food as a ‘simple’ predictor of adult-onset asthma and call for an integrative approach, including a range of modifiable lifestyle factors and further asthma phenotyping.

12 April 2024 in Journal of Patient-Reported Outcomes
Verified
Journal Article
Open access
PDF file
BDBrian M. Doornenbal
Brian M. Doornenbal
TZTim van Zutphen
Tim van Zutphen
LBLise F. E. Beumeler
Lise F. E. Beumeler
RVRimke C. Vos
Rimke C. Vos
MDMark Derks
Mark Derks
JJJessica Kiefte-de Jong
Jessica Kiefte-de Jong
Background: The concept of Positive Health (PH) has gained increasing attention as a way of measuring individuals’ ability to adapt in the face of contextual challenges. However, a suitable measurement instrument for PH that encompasses contextual factors has not yet been developed. This paper responds to this need by developing a Context-specific Positive Health (CPH) measurement instrument that aligns with the Capability Approach (CA). Methods: The measurement instrument was developed and tested among a representative sample of 1002 Dutch internet survey panel members with diverse sociodemographic backgrounds. The instrument was developed in two stages: a preparation phase consisting of focus groups and expert consultations, and a validation among a representative panel of Dutch citizens. The goal of the preparation phase, was to pilot test and refine previously proposed Positive Health questionnaires into an initial version of the CPHQ. The validation phase aimed to examine the initial CPHQ’s factorial validity using Factor Analysis, and its concurrent validity using Multivariate Regression Analysis. Results: The developed questionnaire demonstrated adequate factorial and concurrent validity. Furthermore, it explicitly includes an assessment of resilience, this being a key component of PH. Conclusions: The introduced measurement tool, the CPHQ, comprises 11 dimensions that we have labeled as follows: relaxation, autonomy, fitness, perceived environmental safety, exclusion, social support, financial resources, political representation, health literacy, resilience, and enjoyment. In this article, we present four major contributions. Firstly, we embedded the measurement in a theoretical framework. Secondly, we focused the questionnaire on a key concept of Positive Health - the “ability to adapt.” Thirdly, we addressed issues of health inequality by considering contextual factors. Finally, we facilitated the development of more understandable measurement items.

22 December 2023 in Respiratory Medicine
Verified
Journal Article
Open access
EVEdith Visser
Edith Visser
ABAnneke Ten Brinke
Anneke Ten Brinke
DSDionne Sizoo
Dionne Sizoo
JPJanneke J.S. Pepels
Janneke J.S. Pepels
LHLianne Ten Have
Lianne Ten Have
KJKim de Jong
Kim de Jong
Type 2 (T2) inflammation is a key mechanism in the pathophysiology of asthma. Diet may have immunomodulatory effects, and a role for diet in T2 inflammation has been suggested in the literature. Indeed, diet and food allergies play a role in children with atopic asthma, but less is known about diet in relation to adult asthma, which is often non-atopic. To review the effect of dietary interventions on markers of T2 inflammation in adults with asthma. The databases PubMed, Embase, Cochrane Library, and CINAHL were searched for eligible studies until December 2022. We included studies of all types of foods, nutrients, diets or supplements, either as an exposure or as an intervention, in adults and adolescents with asthma. Outcomes of interest included the T2 biomarkers FeNO, eosinophils, IL-4, IL-5, IL-13, eosinophil cationic protein and eosinophil peroxidase. The methodological quality of eligible studies was systematically evaluated, and the results were summarised according to dietary clusters. The systematic search identified studies on the dietary clusters antioxidants (n = 14), fatty acids, (n = 14), Mediterranean-style diets (n = 5), phytotherapy (n = 7), prebiotics & probiotics (n = 8), vitamin D (n = 7), and other dietary factors (n = 5). Studies within the phytotherapy and omega-3 poly-unsaturated fatty acids (PUFA) clusters showed possible improvements in T2 inflammation. Furthermore, we found little evidence for an effect of antioxidants, prebiotics & probiotics, and Mediterranean-style diets on T2 inflammation. However, heterogeneity in study protocols, methodological shortcomings and limited power of almost all studies make it difficult to fully determine the impact of different dietary approaches on T2 inflammation in asthma. Overall, the current evidence does not support a specific dietary intervention to improve T2 inflammation in asthma. Interventions involving phytotherapy and omega-3 PUFA currently have the best evidence and warrant further evaluation in well-designed and adequately powered studies, while taking into account T2-high phenotypes of asthma.

22 September 2022 in International Journal of Food Sciences and Nutrition
Verified
Journal Article
Closed access
Francesco VisioliFrancesco Visioli
Francesco Visioli
VBVivien Bodereau
Vivien Bodereau
MKMaarten van der Kamp
Maarten van der Kamp
MCMiriam Clegg
Miriam Clegg
JGJing Guo
Jing Guo
WWWalter C. Willett
Walter C. Willett
The majority of university curricula for health professionals does not incorporate courses on human nutrition and its links with human and planetary health. This primarily applies to medical and pharmacy students, who have important counselling roles and are at the forefront of public health. To address this important issue, EIT Food recently launched an online course on nutrition, health, and sustainability. Learners were able to provide feedback on the course through an end-of-course survey and social interaction on the FutureLearn platform. The course was very well attended worldwide and received positive feedback from learners. A total of 3,858 students enrolled in the program, from >20 countries. Learners reported inadequate training on nutrition in their own curriculum and indicated they would use key insights from the course to inform their own practice. This report provides insights from the course, which could be used as guidance for future initiatives.

24 July 2023 in Journal of Psychosomatic Research
Verified
Journal Article
Open access
BNB. Nijenhuis
B. Nijenhuis
TZTim van Zutphen
Tim van Zutphen
PGP. Gul
P. Gul
EOE. Otten
E. Otten
MTMarina Tijssen
Marina Tijssen
Objective: Skater’s cramp is a debilitating disorder in expert speedskaters and recent evidence from muscle and movement studies nominate it is a task-specific dystonia (TSD). Building on these studies we investigated clinical features and personality in skater’s cramp, hypothesizing that similar to other TSDs, trait emotionality would be higher in affected skaters. Methods: In a cross-sectional study we employed the HEXACO inventory to examine the personality of a cohort of skaters with skater’s cramp (n = 26) compared to age, sex, and experience-matched controls (n = 28). Affected skaters were selected based on relevant clinical features important to the diagnosis of TSD. Results: Sentimentality (a sub-factor of emotionality) was higher in affected skaters, but only in the male population. Extraversion was lower in skaters with skater’s cramp. Clinical findings resembled other forms of TSD. Discussion: Higher sentimentality is in line with previous studies in TSD. Lower Extraversion in affected skaters was an unexpected finding that may be a new feature of skater’s cramp and TSD. Due to our small sample size and cross-sectional design, these findings are preliminary, but offer tentative evidence of personality differences in skater’s cramp in line with TSD.