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Immersive Virtual Reality (IVR) has gained popularity in neurorehabilitation for its potential to increase patients’ motivation and engagement. A crucial yet relatively unexplored aspect of IVR interfaces is the patients’ representation in the virtual world, such as with an avatar. A higher level of embodiment over avatars has been shown to enhance motor performance during upper limb training and has the potential to be employed to enhance neurorehabilitation. However, the relationship between avatar embodiment and gait performance remains unexplored. In this work, we present the results of a pilot study with 12 healthy young participants that evaluates the effect of different virtual lower limb representations on foot placement accuracy while stepping over a trail of 16 virtual targets. We compared three levels of virtual representation: i) a full-body avatar, ii) only feet, and iii) no representation. Full-body tracking is computed using standard VR trackers to synchronize the avatar with the participants’ motions. Foot placement accuracy is measured as the distance between the foot’s center of mass and the center of the selected virtual target. Additionally, we evaluated the level of embodiment over each virtual representation through a questionnaire. Our findings indicate that foot placement accuracy increases with some form of virtual representation, either full-body or foot, compared to having no virtual representation. However, the foot and full-body representations do not show significant differences in accuracy. Importantly, we found a negative correlation between the level of embodiment of the foot representation and the distance between the placed foot and the target. However, no such correlation was found for the full-body representation. Our results highlight the importance of embodying a virtual representation of the foot when performing a task that requires accurate foot placement. However, showing a full-body avatar does not appear to further enhance, Human-Robot Interaction

Contains fulltext : 67702.pdf (publisher's version ) (Closed access), Both environment and genetics contribute to the pathogenesis and prevention of colorectal neoplasia. NAD(P)H:quinone oxidoreductase (NQO1) is a detoxification enzyme that is polymorphic and inducible. We investigated interactions between lifestyle factors and polymorphisms in NQO1 and its key regulatory transcription factor NFE2L2 in colorectal adenoma risk. The NQO1 c.609C>T and g.-718A>G and NFE2L2 g.-650C>A, g.-684G>A and g.-686A>G polymorphisms were determined among 740 Dutch adenoma cases and 698 endoscopy-based controls. Dietary intake was assessed by food frequency questionnaire, other lifestyle information by questionnaire. The NQO1 609CT genotype was associated with a higher adenoma risk (OR 1.27, 95% CI 1.00-1.62) compared with the 609CC genotype, whereas the 609TT genotype was not (OR 1.03, 95% CI 0.56-1.88). The higher risk with the NQO1 609CT-genotype was seen among smokers (OR 1.96, 95% CI 1.40-2.76), but not among nonsmokers (OR 0.91, 95% CI 0.62-1.35; interaction p = 0.030). Fruit and vegetable consumption did not protect smokers from adenomas and did not interact with the NQO1 609C>T polymorphism or the NFE2L2 polymorphisms. A higher adenoma risk seen with high fruit and vegetable consumption among NQO1 -718GG genotypes was absent among -718GA genotypes (interaction p = 0.071). Gene-gene interactions were observed between the NQO1 609C>T and NFE2L2 -686A>G polymorphisms (interaction p = 0.056) and between the NQO1 -718 G>A and NFE2L2 -650C>A polymorphisms (interaction p = 0.013). In conclusion: the NQO1 609CT genotype is associated with increased adenoma risk among smokers, which is not diminished by high fruit and vegetable consumption. The observed gene-gene interactions may point to a role for NFE2L2 polymorphisms in NQO1-related adenoma formation.

Contains fulltext : 68313.pdf (publisher's version ) (Closed access), NAD(P)H:quinone oxidoreductase (NQO1) is an inducible detoxification enzyme relevant for colorectal cancer biochemoprevention. We evaluated the influence of recent fruit and vegetable (F&V) consumption and polymorphisms in NQO1 and transcription factor NFE2L2 on rectal NQO1 phenotype and also whether white blood cell (WBC) NQO1 activity reflects rectal activity. Among 94 sigmoidoscopy patients, we assessed F&V consumption by dietary record and determined the NQO1 c.609C > T and g.-718A > G and NFE2L2 g.-650C > A, g.-684G > A, and g.-686A > G polymorphisms. NQO1 mRNA level was measured in rectal biopsies and NQO1 activity in rectal biopsies and WBC. Consumption of F&V did not yield higher mRNA level or activity but rather appeared to have a repressive effect. Rectal activity was higher among NQO1 609CC-genotypes as compared to 609CT-genotypes (P < 0.0001; 609TT-genotypes were absent), whereas mRNA was higher among 609CT-genotypes (P < 0.001). mRNA and activity correlated among NQO1 609CC-genotypes (r = .50, P = 0.0001) but not among 609CT-genotypes (r = .14, P = 0.45). The NFE2L2-684A-allele was associated with higher mRNA levels (P = < 0.05). The other polymorphisms did not affect phenotype significantly. WBC and rectal activity did not correlate. In conclusion, genetic variation, especially the NQO1 609C > T polymorphism, is a more important predictor of rectal NQO1 phenotype than F&V consumption. WBC NQO1 activity is not a good surrogate for rectal activity.

Het eten van groenten en fruit verkleint mogelijk de kans op dikke darmkanker door te stimuleren dat schadelijke stoffen onschadelijk gemaakt worden (ontgifting). Mensen verschillen in hun ontgiftingsvermogen doordat ze verschillend eten, maar ook door genetische aanleg. In het proefschrift wordt het samenspel onderzocht tussen het eten van groenten en fruit en genetische verschillen in twee typen ontgiftingseiwitten, GST en NQO1. Bij 94 mensen is nagegaan in hoeverre groente- en fruitconsumptie en aangeboren verschillen de hoeveelheid GST- en NQO1-eiwitten in darmweefsel en bloed beïnvloeden. Bij 1450 mensen, van wie de helft darmpoliepen had, is bekeken of het vóórkomen van dit voorstadium van dikke darmkanker samenhangt met groente- en fruitconsumptie en aangeboren verschillen in GST en NQO1. Er bleek geen gunstiger effect van groenten en fruit voor mensen met bepaalde aangeboren verschillen. Er hoeft geen aangepast advies voor groente- en fruitconsumptie te worden gegeven op basis van aangeboren variatie in de onderzochte ontgiftingseiwitten.

Contains fulltext : 51701.pdf (publisher's version ) (Closed access), High glutathione S-transferase (GST) activity may contribute to colorectal cancer prevention. Functional polymorphisms are known in the GSTM1, GSTT1, GSTA1 and GSTP1 genes. The influence of these GST polymorphisms and recent fruit and vegetable consumption on GST levels and activity has not been investigated simultaneously in a human population. Also, it is not clear if blood GST activity reflects rectal GST activity. Therefore, we determined GST polymorphisms in 94 patients scheduled for sigmoidoscopy. Rectal GST isoenzyme levels (GSTM1, GSTM2, GSTT1, GSTA and GSTP1) were measured by quantitative western blotting, and rectal and white blood cell total GST activities were measured spectrophotometrically using 1-chloro-2,4-dinitrobenzene (CDNB) as a substrate. Vegetable and fruit consumption was assessed by dietary record. As expected, the GSTM1 and GSTT1 deletion polymorphisms, and the GSTA1 g.-69C-->T polymorphism significantly affected the respective isoenzyme levels. Also, rectal GST isoenzyme levels differed between those with and without recent consumption of Alliaceae, Cucurbitaceae, Apiaceae and citrus fruit. Rectal GST activity, however, was not clearly influenced by fruit and vegetable consumption. It was most significantly determined by the GSTP1 c.313A-->G polymorphism; compared with the 313AA genotypes, the 313AG and 313GG genotypes showed 36 and 67 nmol/min/mg protein (P < 0.001) lower GST activity, respectively. The correlation between rectal and white blood cell GST activities was low (r = 0.40, P < 0.001), and the relevance of the various genetic and dietary factors appeared to differ between the two tissues. In conclusion, this study indicates that the GST enzyme system is influenced by both GST polymorphisms and consumption of fruits and vegetables. The latter appeared more important for individual rectal GST isoenzyme levels than for total GST activity, which could affect detoxification of isoenzyme-specific substrates. The study results do no sup

Item does not contain fulltext, OBJECTIVE: Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with a decreased risk of colorectal tumors. Single nucleotide polymorphisms (SNPs) in target genes of NSAID action, and their haplotypes, might modulate this protective effect. METHODS: A case-control study including 724 cases and 682 controls was used to evaluate the effect of NSAIDs on colorectal adenoma risk in The Netherlands, a country in which NSAID use is relatively low. Cases and controls were classified according to presence or absence of endoscopy-proven, pathology-confirmed colorectal adenomas, ever in their lives. Thirteen SNPs in four genes (PPARdelta, PPARgamma, PTGS1 and PTGS2) were genotyped in 787 subjects (384 cases and 403 controls). RESULTS: Compared to non-regular users (< 12 times/year), regular users of NSAIDs (> or = 12 times/year) had a lower risk of colorectal adenomas (odds ratio (OR): 0.75, 95% confidence interval (CI): 0.56-0.99). The results were similar for aspirin only. We found an interaction between SNP c.-789C>T in PPARdelta and NSAID use (P=0.03). The protective effect of NSAIDs was strengthened for regular users with the PPARdelta CT or TT genotypes (OR: 0.35, 95%CI: 0.11-1.13), whereas a positive association was observed for non-regular users with these genotypes (OR: 2.24, 95%CI: 1.06-4.73) as compared to non-regular users with the CC genotype. Also, a statistically significant interaction between a major haplotype containing the minor allele of this SNP and NSAID use was observed. CONCLUSIONS: This study confirms the protective effect of NSAIDs and suggests a modulating effect of a SNP in the promoter of PPARdelta.

Item does not contain fulltext, The possible interplay between cruciferous vegetable consumption, functional genetic variations in glutathione S-transferases (GST) M1, T1, P1, and A1, and colorectal adenomas, was investigated in a Dutch case-control study. The GSTM1 and GSTT1 deletion polymorphisms, and the single nucleotide polymorphisms in GSTP1 (A313G) and in GSTA1 (C-69T) were assessed among 746 cases who developed colorectal adenomas and 698 endoscopy-based controls without any type of colorectal polyps. High and low cruciferous vegetable consumption was defined based on a median split in the control group. High consumption was slightly positively associated with colorectal adenomas [odds ratio (OR) 1.15; 95% confidence interval, 0.92-1.44]. For GSTP1, a positive association with higher cruciferous vegetable intake was only apparent in individuals with the low-activity GSTP1 genotype (GG genotype, OR 1.94; 95% confidence interval, 1.02-3.69). This interaction was more pronounced in men, with higher age and with higher meat intake. The GSTA1 polymorphism may have a modifying role as well: the OR for higher intake compared with lower intake was 1.57 (0.93-2.65) for individuals homozygous for the low expression variant (TT genotype). This seemed to be stronger with younger age and higher red meat intake. Cruciferous vegetable consumption and the combined GSTA1 and GSTP1 genotypes showed a statistically significant interaction (P = 0.034). The GSTM1 and GSTT1 genotypes did not seem to modify the association between cruciferous vegetable intake and colorectal adenomas. In conclusion, GSTP1 and GSTA1 genotypes might modulate the association between cruciferous vegetable intake and colorectal adenomas.

Objectives: To examine age related changes in physical functioning in elderly men and women. Design: Prospective, population based study. Setting: Population of 15 rural and urban centres in 10 European countries. Participants: Altogether 3496 men and women born between 1900 and 1920 who participated in the baseline survey of the HALE project in 1988-1991. The study population was examined again about five (in 1993-1995) and 10 (in 1999-2001) years after the baseline examination. Main outcome measures: Physical functioning was measured by means of a self administered questionnaire of activities of daily living (ADL). Dichotomised prevalence of disability and need for help in self care and mobility ADL were used as dependent variables in the analyses. Results: Prevalence of disability and need for help tended to be higher in women than in men and in mobility abilities than in self care activities. Disability and need for help increased with advancing age but ameliorated over time from one birth cohort to another. In longitudinal analyses this beneficial time trend was independent of the effect of age, study, and region in self care disability in men and women (OR 0.85, 95% CI 0.75 to 0.97 and OR 0.64, 95% CI 0.43 to 0.97, respectively) and self care need for help in men (OR 0.83, 95% CI 0.70 to 0.96). Mobility disability among men and self care disability among women decreased more in the south than in the north. Conclusion: While European populations are aging, the proportions of elderly people with disability are decreasing. These results suggest that dynamics of functioning may differ across cultures. Future studies are needed to clarify which potentially modifiable and culturally determined factors protect against functional decline.