2,121 research outputs found
The oral microbiome of denture wearers is influenced by natural dentition
Objectives:
The composition of dental plaque has been well defined, whereas currently there is limited understanding of the composition of denture plaque and how it directly influences denture related stomatitis (DS). The aims of this study were to compare the microbiomes of denture wearers, and to understand the implications of these towards inter-kingdom and host-pathogen interactions within the oral cavity.
Methods:
Swab samples were obtained from 123 participants wearing either a complete or partial denture; the bacterial composition of each sample was determined using bar-coded illumina MiSeq sequencing of the bacterial hypervariable V4 region of 16S rDNA. Sequencing data processing was undertaken using QIIME, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. The dentures were sonicated to remove the microbial flora residing on the prosthesis, sonicate was then cultured using diagnostic colorex Candida media. Samples of unstimulated saliva were obtained and antimicrobial peptides (AMP) levels were measured by ELISA.
Results:
We have shown that dental and denture plaques are significantly distinct both in composition and diversity and that the oral microbiome composition of a denture wearer is variable and is influenced by the location within the mouth. Dentures and mucosa were predominantly made up of Bacilli and Actinobacteria. Moreover, the presence of natural teeth has a significant impact on the overall microbial composition, when compared to the fully edentulous. Furthermore, increasing levels of Candida spp. positively correlate with Lactobacillus spp. AMPs were quantified, though showed no specific correlations.
Conclusions:
This is the first study to provide a detailed understanding of the oral microbiome of denture wearers and has provided evidence that DS development is more complex than simply a candidal infection. Both fungal and bacterial kingdoms clearly play a role in defining the progression of DS, though we were unable to show a defined role for AMPs
Unfolding-Based Process Discovery
This paper presents a novel technique for process discovery. In contrast to
the current trend, which only considers an event log for discovering a process
model, we assume two additional inputs: an independence relation on the set of
logged activities, and a collection of negative traces. After deriving an
intermediate net unfolding from them, we perform a controlled folding giving
rise to a Petri net which contains both the input log and all
independence-equivalent traces arising from it. Remarkably, the derived Petri
net cannot execute any trace from the negative collection. The entire chain of
transformations is fully automated. A tool has been developed and experimental
results are provided that witness the significance of the contribution of this
paper.Comment: This is the unabridged version of a paper with the same title
appearead at the proceedings of ATVA 201
Policy interpretations and manifestation of biocultural diversity in urbanized Europe : conservation of lived biodiversity
Biocultural diversity, which refers to the inextricable link between biodiversity and cultural diversity, has been predominantly associated with the traditional ways in which indigenous people in tropical countries interact with the natural environment. But it does not have to be restricted to these circumstances. Biocultural diversity may also be regarded as an interesting concept for understanding how people in industrialized and globalized societies deal with nature. This paper explores biocultural diversity in 20 European cities by considering (i) how biocultural diversity is interpreted in urban planning and governance, and (ii) what actual manifestations of biocultural diversity are present in these cities. Despite the fact that the concept of biocultural diversity was hardly recognized by city authorities, interviewees gave many examples of how biodiversity and cultural diversity are taken into account in (in) formal city policies. The research revealed two main manifestations of biocultural diversity within urban Europe: biocultural diversity grounded in ecological features, and cultural values as a basic foundation for biocultural diversity. Consequently, urban biocultural diversity was found to have two spatial levels: the city level and the site level. The former is the domain of governmental policy makers who discuss biocultural diversity in 'green space networks' in a rather static way. The latter is the domain where citizens participate in decisionmaking and the management of green spaces; it is here that cultural dynamics are most acknowledged.Peer reviewe
Food anticipation in Bmal1-/- and AAV-Bmal1 rescued mice: a reply to Fuller et al
ABSTRACT: Evidence that circadian food-anticipatory activity and temperature rhythms are absent in Bmal1 knockout mice and rescued by restoration of Bmal1 expression selectively in the dorsomedial hypothalamus was published in 2008 by Fuller et al and critiqued in 2009 by Mistlberger et al. Fuller et al have responded to the critique with new information. Here we update our critique in the light of this new information. We also identify and correct factual and conceptual errors in the Fuller et al response. We conclude that the original results of Fuller et al remain inconclusive and fail to clarify the role of Bmal1 or the dorsomedial hypothalamus in the generation of food-entrainable rhythms in mic
The Relation between Oral Candida Load and Bacterial Microbiome Profiles in Dutch Older Adults.
Currently there are no evidence-based ecological measures for prevention of overgrowth and subsequent infection by fungi in the oral cavity. The aim of this study was to increase our knowledge on fungal-bacterial ecological interactions. Salivary Candida abundance of 82 Dutch adults aged 58-80 years was established relative to the bacterial load by quantitative PCR analysis of the Internal Transcribed (ITS) region (Candida) and 16S rDNA gene (bacteria). The salivary microbiome was assessed using barcoded pyrosequencing of the bacterial hypervariable regions V5-V7 of 16S rDNA. Sequencing data was preprocessed by denoising and chimera removal, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. Both OTU-based (PCA, diversity statistics) and phylogeny-based analyses (UniFrac, PCoA) were performed. Saliva of Dutch older adults contained 0-4 × 108 CFU/mL Candida with a median Candida load of 0.06%. With increased Candida load the diversity of the salivary microbiome decreased significantly (p<0.001). Increase in the Candida load correlated positively with class Bacilli, and negatively with class Fusobacteria, Flavobacteria, and Bacteroidia. Microbiomes with high Candida load were less diverse and had a distinct microbial composition towards dominance by saccharolytic and acidogenic bacteria - streptococci. The control of the acidification of the oral environment may be a potential preventive measure for Candida outgrowth that should be evaluated in longitudinal clinical intervention trials. © 2012 Kraneveld et al
Measurement of fraction unbound paclitaxel in human plasma
The clinical pharmacokinetic behavior of paclitaxel (Taxol) is distinctly
nonlinear, with disproportional increases in systemic exposure with an
increase in dose. We have recently shown that Cremophor EL, the
formulation vehicle used for i.v. administration of paclitaxel, alters
drug distribution as a result of micellar entrapment of paclitaxel, and we
speculated that the free drug fraction (fu) is dependent on dose and
time-varying concentrations of Cremophor EL in the central plasma
compartment. To test this hypothesis, a reproducible equilibrium dialysis
method has been developed for the measurement of paclitaxel fu in plasma.
Equilibrium dialysis was performed at 37 degrees C in a humidified
atmosphere of 5% CO(2) using 2.0-ml polypropylene test tubes. Experiments
were carried out with 260-microliter aliquots of plasma containing a
tracer amount of [G-(3)H]paclitaxel with high-specific activity against an
equal volume of 0.01 M phosphate buffer (pH 7.4). Drug concentrations were
measured by both reversed-phase HPLC and liquid scintillation counting.
Using this method, fu has been measured in three patients receiving three
consecutive 3-weekly courses of paclitaxel at dose levels of 135, 175, and
225 mg/m(2) and found to range between 0.036 and 0.079. The method was
also used to define concentration-time profiles of unbound drug, estimated
from the product of the total plasma concentration and fu
Learning through social spaces: migrant women and lifelong learning in post-colonial London
This article shows how migrant women engage in learning through social spaces. It argues that such spaces are little recognised, and that there are multiple ways in which migrant women construct and negotiate their informal learning through socialising with other women in different informal modes. Additionally, the article shows how learning is shaped by the socio-political, geographical and multicultural context of living in London, outlining ways in which gendered and racialised identities shape, construct and constrain participation in lifelong learning. The article shows that one way in which migrant women resist (post)colonial constructions of difference is by engaging in informal and non-formal lifelong learning, arguing that the benefits are (at least) two-fold. The women develop skills (including language skills) but also use their informal learning to develop what is referred to in this article as 'relational capital'. The article concludes that informal lifelong learning developed through social spaces can enhance a sense of belonging for migrant women
Single-Limb Irradiation Induces Local and Systemic Bone Loss in a Murine Model
Increased fracture risk is commonly reported in cancer patients receiving radiotherapy, particularly at sites within the field of treatment. The direct and systemic effects of ionizing radiation on bone at a therapeutic dose are not well-characterized in clinically relevant animal models. Using 20-week-old male C57Bl/6 mice, effects of irradiation (right hindlimb; 2 Gy) on bone volume and microarchitecture were evaluated prospectively by microcomputed tomography and histomorphometry and compared to contralateral-shielded bone (left hindlimb) and non-irradiated control bone. One week postirradiation, trabecular bone volume declined in irradiated tibias (-22%; p < 0.0001) and femurs (-14%; p = 0.0586) and microarchitectural parameters were compromised. Trabecular bone volume declined in contralateral tibias (-17%; p = 0.003), and no loss was detected at the femur. Osteoclast number, apoptotic osteocyte number, and marrow adiposity were increased in irradiated bone relative to contralateral and non-irradiated bone, whereas osteoblast number was unchanged. Despite no change in osteoblast number 1 week postirradiation, dynamic bone formation indices revealed a reduction in mineralized bone surface and a concomitant increase in unmineralized osteoid surface area in irradiated bone relative to contralateral and non-irradiated control bone. Further, dose-dependent and time-dependent calvarial culture and in vitro assays confirmed that calvarial osteoblasts and osteoblast-like MC3T3 cells were relatively radioresistant, whereas calvarial osteocyte and osteocyte-like MLO-Y4 cell apoptosis was induced as early as 48 hours postirradiation (4 Gy). In osteoclastogenesis assays, radiation exposure (8 Gy) stimulated murine macrophage RAW264.7 cell differentiation, and coculture of irradiated RAW264.7 cells with MLO-Y4 or murine bone marrow cells enhanced this effect. These studies highlight the multifaceted nature of radiation-induced bone loss by demonstrating direct and systemic effects on bone and its many cell types using clinically relevant doses; they have important implications for bone health in patients treated with radiation therapy
Standards of Evidence in Chronobiology: Critical Review of a Report that Restoration of Bmal1 Expression in the Dorsomedial Hypothalamus is Sufficient to Restore Circadian Food Anticipatory Rhythms in Bmal1-/- Mice
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