Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
19 result(s) for "Stock, Valerie"
Sort by:
Uptake and effects of orally ingested polystyrene microplastic particles in vitro and in vivo
Evidence exists that humans are exposed to plastic microparticles via diet. Data on intestinal particle uptake and health-related effects resulting from microplastic exposure are scarce. Aim of the study was to analyze the uptake and effects of microplastic particles in human in vitro systems and in rodents in vivo. The gastrointestinal uptake of microplastics was studied in vitro using the human intestinal epithelial cell line Caco-2 and thereof-derived co-cultures mimicking intestinal M-cells and goblet cells. Different sizes of spherical fluorescent polystyrene (PS) particles (1, 4 and 10 µm) were used to study particle uptake and transport. A 28-days in vivo feeding study was conducted to analyze transport at the intestinal epithelium and oxidative stress response as a potential consequence of microplastic exposure. Male reporter gene mice were treated three times per week by oral gavage with a mixture of 1 µm (4.55 × 107 particles), 4 µm (4.55 × 107 particles) and 10 µm (1.49 × 106 particles) microplastics at a volume of 10 mL/kg/bw. Effects of particles on macrophage polarization were investigated using the human cell line THP-1 to detect a possible impact on intestinal immune cells. Altogether, the results of the study demonstrate the cellular uptake of a minor fraction of particles. In vivo data show the absence of histologically detectable lesions and inflammatory responses. The particles did not interfere with the differentiation and activation of the human macrophage model. The present results suggest that oral exposure to PS microplastic particles under the chosen experimental conditions does not pose relevant acute health risks to mammals.
NanoPASS: an easy-to-use user interface for nanoparticle dosimetry with the 3DSDD model
Nanoparticles exhibit a specific diffusion and sedimentation behavior under cell culture conditions as used in nantoxicological in vitro testing. How a particular particle suspension behaves depends on the particular physicochemical characteristics of the particles and the cell culture system. Only a fraction of the nanoparticles applied to a cell culture will thus reach the cells within a given time frame. Therefore, dosimetric calculations are essential not only to determine the exact fraction of nanoparticles that has come into contact with the cells, but also to ensure experimental comparability and correct interpretation of results, respectively. Yet, the use of published dosimetry models is limited. Not the least because the correct application of these in silico tools usually requires bioinformatics knowledge, which often is perceived a hurdle. Moreover, not all models are freely available and accessible. In order to overcome this obstacle, we have now developed an easy-to-use interface for our recently published 3DSDD dosimetry model, called NanoPASS (NanoParticle Administration Sedimentation Simulator). The interface is freely available to all researchers. It will facilitate the use of in silico dosimetry in nanotoxicology and thus improve interpretation and comparability of in vitro results in the field.
Intestinal and hepatic effects of iron oxide nanoparticles
Iron oxide nanoparticles gain increasing attention due to their broad industrial use. However, safety concerns exist since their effects on human cells are still under investigation. The presence of iron oxide nanoparticles in the food pigment E172 has been shown recently. Here, we studied four iron oxide nanoparticles, one food pigment E172 and the ionic control FeSO4 regarding dissolution in biological media, uptake and transport, and cellular effects in vitro in human intestinal Caco-2 and HepaRG hepatocarcinoma cells. The iron oxide nanoparticles passed the gastrointestinal passage without dissolution and reached the intestine in the form of particles. Minor uptake was seen into Caco-2 cells but almost no transport to the basolateral site was detected for any of the tested particles. HepaRG cells showed higher particle uptake. Caco-2 cells showed no alterations in reactive oxygen species production, apoptosis, or mitochondrial membrane potential, whereas two particles induced apoptosis in HepaRG cells, and one altered mitochondrial membrane potential at non-cytotoxic concentrations. No correlation between physicochemical particle characteristics and cellular effects was observed, thus emphasizing the need for case-by-case assessment of iron oxide nanoparticles.
Impact of iron oxide nanoparticles on xenobiotic metabolism in HepaRG cells
Iron oxide nanoparticles are used in various industrial fields, as a tool in biomedicine as well as in food colorants, and can therefore reach human metabolism via oral uptake or injection. However, their effects on the human body, especially the liver as one of the first target organs is still under elucidation. Here, we studied the influence of different representative iron oxide materials on xenobiotic metabolism of HepaRG cells. These included four iron oxide nanoparticles, one commercially available yellow food pigment (E172), and non-particulate ionic control FeSO4. The nanoparticles had different chemical and crystalline structures and differed in size and shape and were used at a concentration of 50 µg Fe/mL. We found that various CYP enzymes were downregulated by some but not all iron oxide nanoparticles, with the Fe3O4-particle, both γ-Fe2O3-particles, and FeSO4 exhibiting the strongest effects, the yellow food pigment E172 showing a minor effect and an α-Fe2O3 nanoparticle leading to almost no inhibition of phase I machinery. The downregulation was seen at the mRNA, protein expression, and activity levels. Thereby, no dependency on the size or chemical structure was found. This underlines the difficulty of the grouping of nanomaterials regarding their physiological impact, suggesting that every iron oxide nanoparticle species needs to be evaluated in a case-by-case approach.
Acute stress improves the effectivity of cognitive emotion regulation in men
Emotion regulation is crucial for coping with stressors but in turn can also be influenced by stress. Initial studies provided mixed evidence showing either beneficial or impairing stress effects on cognitive emotion regulation depending on stress timing, sex or the regulatory strategy. Here, we investigated the impact of acute stress on different emotion regulation strategies in men and women. N = 118 healthy participants were subjected to the Trier Social Stress Test or a control condition after which they completed an emotion regulation paradigm, requiring them to regulate their emotions in response to negative pictures using reappraisal or distraction. Cortisol levels were repeatedly measured to quantify changes in HPA axis activity. Affective ratings and pupil dilation served to measure emotion regulation success and the cognitive effort to regulate emotions. Stress reduced arousal and increased valence and success ratings for reappraisal in men, whereas no significant stress effects were found in women. Moreover, stressed men displayed a significant expansion of pupil diameter during reappraisal suggesting enhanced cognitive regulatory engagement, which ultimately may have led to better emotion regulation outcomes. Cortisol secretion positively correlated with subjective reappraisal success in men, suggesting a glucocorticoid-driven mechanism that may promote emotion regulatory performance in the aftermath of stress.
Evidence for enhanced multi-component behaviour in Tourette syndrome – an EEG study
Evidence suggests that Tourette syndrome is characterized by an increase in dopamine transmission and structural as well as functional changes in fronto-striatal circuits that might lead to enhanced multi-component behaviour integration. Behavioural and neurophysiological data regarding multi-component behaviour was collected from 15 patients with Tourette syndrome (mean age = 30.40 ± 11.10) and 15 healthy controls (27.07 ± 5.44), using the stop-change task. In this task, participants are asked to sometimes withhold responses to a Go stimulus (stop cue) and change hands to respond to an alternative Go stimulus (change cue). Different onset asynchronies between stop and change cues were implemented (0 and 300 ms) in order to vary task difficulty. Tourette patients responded more accurately than healthy controls when there was no delay between stop and change stimulus, while there was no difference in the 300 ms delay condition. This performance advantage was reflected in a smaller P3 event related potential. Enhanced multi-component behaviour in Tourette syndrome is likely based on an enhanced ability to integrate information from multiple sources and translate it into an appropriate response sequence. This may be a consequence of chronic tic control in these patients, or a known fronto-striatal networks hyperconnectivity in Tourette syndrome.
New directions in supply-chain management
\"Technology has introduced dramatic new efficiencies to supply chain design, management, and control--but only to those who can open their minds to these new methods and strategies. This book presents innovative articles from eighteen of today's top young Ph.D. scholars, each based on discussions at the 2000 Frank Batten Young Leaders Forum of the College of William and Mary.
Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial
Objective To determine whether the probiotic Lactobacillus reuteri DSM 17938 reduces crying or fussing in a broad community based sample of breastfed infants and formula fed infants with colic aged less than 3 months. Design Double blind, placebo controlled randomised trial. Setting Community based sample (primary and secondary level care centres) in Melbourne, Australia. Participants 167 breastfed infants or formula fed infants aged less than 3 months meeting Wessel’s criteria for crying or fussing: 85 were randomised to receive probiotic and 82 to receive placebo. Interventions Oral daily L reuteri (1×108 colony forming units) versus placebo for one month. Main outcomes measures The primary outcome was daily duration of cry or fuss at 1 month. Secondary outcomes were duration of cry or fuss; number of cry or fuss episodes; sleep duration of infant at 7, 14, and 21 days, and 1 and 6 months; maternal mental health (Edinburgh postnatal depression subscale); family functioning (paediatric quality of life inventory), parent quality adjusted life years (assessment of quality of life) at 1 and 6 months; infant functioning (paediatric quality of life inventory) at 6 months; infant faecal microbiota (microbial diversity, colonisation with Escherichia coli), and calprotectin levels at 1 month. In intention to treat analyses the two groups were compared using regression models adjusted for potential confounders. Results Of 167 infants randomised from August 2011 to August 2012, 127 (76%) were retained to primary outcome; of these, a subset was analysed for faecal microbial diversity, E coli colonisation, and calprotectin levels. Adherence was high. Mean daily cry or fuss time fell steadily in both groups. At 1 month, the probiotic group cried or fussed 49 minutes more than the placebo group (95% confidence interval 8 to 90 minutes, P=0.02); this mainly reflected more fussing, especially for formula fed infants. The groups were similar on all secondary outcomes. No study related adverse events occurred. ConclusionsL reuteri DSM 17938 did not benefit a community sample of breastfed infants and formula fed infants with colic. These findings differ from previous smaller trials of selected populations and do not support a general recommendation for the use of probiotics to treat colic in infants. Trial registration Current Controlled Trials ISRCTN95287767.
Probiotics to improve outcomes of colic in the community: Protocol for the Baby Biotics randomised controlled trial
Background Infant colic, characterised by excessive crying/fussing for no apparent cause, affects up to 20% of infants under three months of age and is a great burden to families, health professionals and the health system. One promising approach to improving its management is the use of oral probiotics. The Baby Biotics trial aims to determine whether the probiotic Lactobacillus reuteri DSM 17938 is effective in reducing crying in infants less than three months old (<13.0 weeks) with infant colic when compared to placebo. Methods/Design Design: Double-blind, placebo-controlled randomised trial in Melbourne, Australia. Participants: 160 breast and formula fed infants less than three months old who present either to clinical or community services and meet Wessel’s criteria of crying and/or fussing. Intervention: Oral once-daily Lactobacillus reuteri (1x10 8 cfu) versus placebo for one month. Primary outcome: Infant crying/fussing time per 24 hours at one month. Secondary outcomes: i) number of episodes of infant crying/fussing per 24 hours and ii) infant sleep duration per 24 hours (at 7, 14, 21, 28 days and 6 months); iii) maternal mental health scores, iv) family functioning scores, v) parent quality adjusted life years scores, and vi) intervention cost-effectiveness (at one and six months); and vii) infant faecal microbiota diversity, viii) infant faecal calprotectin levels and ix) Eschericia coli load (at one month only). Analysis: Primary and secondary outcomes for the intervention versus control groups will be compared with t tests and non-parametric tests for continuous data and chi squared tests for dichotomous data. Regression models will be used to adjust for potential confounding factors. Intention-to-treat analysis will be applied. Discussion An effective, practical and acceptable intervention for infant colic would represent a major clinical advance. Because our trial includes breast and formula-fed babies, our results should generalise to most babies with colic. If cost-effective, the intervention’s simplicity is such that it could be widely taken up as a new standard of care in the primary and secondary care sectors. Trial Registration Current Controlled Trials ISRCTN95287767