88 research outputs found

    Lithiumchloride effectief tegen varroa?

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    Association of oral health with body weight:a prospective study in community-dwelling older adults

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    Background: To prevent involuntary weight loss in older people, the knowledge about factors affecting body weight (BW) is essential. Therefore, we aimed to investigate the longitudinal associations of multiple oral health aspects with BW in community-dwelling older adults. Methods: This analysis is based on prospective data with a 10-year follow-up of 657 Dutch community-dwelling older adults (age 66.4 ± 5.8 years, 54% female) from the Longitudinal Aging Study Amsterdam. Participants’ characteristics, BW, and 12 oral health variables (teeth, dentures, nine oral problems, self-rated oral health) were assessed in 2005/07 and 2015/16. The association between oral health and BW was analyzed by mixed models and adjusted for demographic, socio-economic, smoking, health, and functional aspects considering data of both assessments. Results: Mean BW was 79.1 ± 13.3 kg at baseline (B) and 77.6 ± 13.8 kg at follow-up (FU). At baseline, 29.6% of the participants reported being edentulous (FU:34.4%) and 55.8% to wear dentures (FU:62.3%). Dental pain while chewing was the oral problem with the lowest (B:5.2%, FU:6.6%) and xerostomia with the highest prevalence at both examinations (B:24.3%, FU:30.0%). Most participants rated their oral status as healthy (B:65.2%, FU:66.9%). Neither edentulism and denture use nor oral problems showed a longitudinal association with BW. In contrast, self-rated oral health was associated with BW (b = 0.724, SE = 0.296, p = 0.015) after adjusting for multiple confounders. Conclusions: In community-dwelling older adults self-rated oral health may indicate changes in body weight in the long term. Therefore, this simple measure could serve to identify a risk for weight loss and to initiate oral interventions in clinical practice

    Defining the healthy "core microbiome" of oral microbial communities

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    <p>Abstract</p> <p>Background</p> <p>Most studies examining the commensal human oral microbiome are focused on disease or are limited in methodology. In order to diagnose and treat diseases at an early and reversible stage an in-depth definition of health is indispensible. The aim of this study therefore was to define the healthy oral microbiome using recent advances in sequencing technology (454 pyrosequencing).</p> <p>Results</p> <p>We sampled and sequenced microbiomes from several intraoral niches (dental surfaces, cheek, hard palate, tongue and saliva) in three healthy individuals. Within an individual oral cavity, we found over 3600 unique sequences, over 500 different OTUs or "species-level" phylotypes (sequences that clustered at 3% genetic difference) and 88 - 104 higher taxa (genus or more inclusive taxon). The predominant taxa belonged to Firmicutes (genus <it>Streptococcus</it>, family <it>Veillonellaceae</it>, genus <it>Granulicatella</it>), Proteobacteria (genus <it>Neisseria</it>, <it>Haemophilus</it>), Actinobacteria (genus <it>Corynebacterium</it>, <it>Rothia</it>, <it>Actinomyces</it>), Bacteroidetes (genus <it>Prevotella</it>, <it>Capnocytophaga, Porphyromonas</it>) and Fusobacteria (genus <it>Fusobacterium</it>).</p> <p>Each individual sample harboured on average 266 "species-level" phylotypes (SD 67; range 123 - 326) with cheek samples being the least diverse and the dental samples from approximal surfaces showing the highest diversity. Principal component analysis discriminated the profiles of the samples originating from shedding surfaces (mucosa of tongue, cheek and palate) from the samples that were obtained from solid surfaces (teeth).</p> <p>There was a large overlap in the higher taxa, "species-level" phylotypes and unique sequences among the three microbiomes: 84% of the higher taxa, 75% of the OTUs and 65% of the unique sequences were present in at least two of the three microbiomes. The three individuals shared 1660 of 6315 unique sequences. These 1660 sequences (the "core microbiome") contributed 66% of the reads. The overlapping OTUs contributed to 94% of the reads, while nearly all reads (99.8%) belonged to the shared higher taxa.</p> <p>Conclusions</p> <p>We obtained the first insight into the diversity and uniqueness of individual oral microbiomes at a resolution of next-generation sequencing. We showed that a major proportion of bacterial sequences of unrelated healthy individuals is identical, supporting the concept of a core microbiome at health.</p

    Classification of Quantitative Light-Induced Fluorescence Images Using Convolutional Neural Network

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    Images are an important data source for diagnosis and treatment of oral diseases. The manual classification of images may lead to misdiagnosis or mistreatment due to subjective errors. In this paper an image classification model based on Convolutional Neural Network is applied to Quantitative Light-induced Fluorescence images. The deep neural network outperforms other state of the art shallow classification models in predicting labels derived from three different dental plaque assessment scores. The model directly benefits from multi-channel representation of the images resulting in improved performance when, besides the Red colour channel, additional Green and Blue colour channels are used.Comment: Full version of ICANN 2017 submissio

    Transcriptional activity around bacterial cell death reveals molecular biomarkers for cell viability

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    <p>Abstract</p> <p>Background</p> <p>In bacteriology, the ability to grow in selective media and to form colonies on nutrient agar plates is routinely used as a retrospective criterion for the detection of living bacteria. However, the utilization of indicators for bacterial viability-such as the presence of specific transcripts or membrane integrity-would overcome bias introduced by cultivation and reduces the time span of analysis from initiation to read out. Therefore, we investigated the correlation between transcriptional activity, membrane integrity and cultivation-based viability in the Gram-positive model bacterium <it>Bacillus subtilis</it>.</p> <p>Results</p> <p>We present microbiological, cytological and molecular analyses of the physiological response to lethal heat stress under accurately defined conditions through systematic sampling of bacteria from a single culture exposed to gradually increasing temperatures. We identified a coherent transcriptional program including known heat shock responses as well as the rapid expression of a small number of sporulation and competence genes, the latter only known to be active in the stationary growth phase.</p> <p>Conclusion</p> <p>The observed coordinated gene expression continued even after cell death, in other words after all bacteria permanently lost their ability to reproduce. Transcription of a very limited number of genes correlated with cell viability under the applied killing regime. The transcripts of the expressed genes in living bacteria – but silent in dead bacteria-include those of essential genes encoding chaperones of the protein folding machinery and can serve as molecular biomarkers for bacterial cell viability.</p

    A salivary metabolite signature that reflects gingival host-microbe interactions: instability predicts gingivitis susceptibility

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    Several proteins and peptides in saliva were shown to stimulate gingival wound repair, but the role of salivary metabolites in this process remains unexplored. In vitro gingival re-epithelialization kinetics were determined using unstimulated saliva samples from healthy individuals collected during an experimental gingivitis study. Elastic net regression with stability selection identified a specific metabolite signature in a training dataset that was associated with the observed re-epithelialization kinetics and enabled its prediction for all saliva samples obtained in the clinical study. This signature encompassed ten metabolites, including plasmalogens, diacylglycerol and amino acid derivatives, which reflect enhanced host-microbe interactions. This association is in agreement with the positive correlation of the metabolite signature with the individual’s gingival bleeding index. Remarkably, intra-individual signature-variation over time was associated with elevated risk for gingivitis development. Unravelling how these metabolites stimulate wound repair could provide novel avenues towards therapeutic approaches in patients with impaired wound healing capacity.</p

    Which patients with ES-SCLC are most likely to benefit from more aggressive radiotherapy: A secondary analysis of the Phase III CREST trial

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    Introduction: In ES-SCLC patients with residual intrathoracic disease after first-line chemotherapy, the addition of thoracic radiotherapy reduces the risk of intrathoracic recurrence, and improves 2-year survival. To identify patient subgroups for future trials investigating higher dose (extra)thoracic radiotherapy, we investigated the prognostic importance of number and sites of metastases in patients included in the CREST trial. Materials/methods: Additional data on sites and numbers of metastases were collected from individual records of 260 patients from the top 9 recruiting centers in the randomized CREST trial (53% of 495 study patients), which compared thoracic radiotherapy (TRT) to no TRT in ES-SCLC patients after any response to chemotherapy. All patients received prophylactic cranial irradiation. Results: The clinical characteristics and outcomes of the 260 patients analyzed here did not differ significantly from that of the other 235 patients included in the CREST trial, except that fewer patients had a WHO = 0 performance status (24% vs 45%), and a higher proportion had WHO = 2 (15% vs 5%; p <0.0001). No distant metastases were recorded in 5%, 39% had metastases confined to one organ, 34% to two, and 22% to three or more organ sites. Metastases were present in the liver (47%), bone (40%), lung (28%), extrathoracic (non-supraclavicular) lymph nodes (19%), supraclavicular nodes (18%), adrenals (17%) and other sites (12%). The OS (p = 0.02) and PFS (p = 0.04) were significantly better in patients with 2 or fewer metastases, with OS significantly worse if liver (p = 0.03) and/or bone metastases (p= 0.04) were present. Discussion: This analysis of patients recruited from the top 9 accruing centers in the CREST trial suggests that future studies evaluating more intensive thoracic and extra-thoracic radiotherapy in ES-SCLC should focus on patients with fewer than 3 distant metastases. (C) 2017 The Author(s). Published by Elsevier Ireland Ltd

    Maturation of the infant respiratory microbiota, environmental drivers and health consequences: a prospective cohort study

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    Rationale: Perinatal and postnatal influences are presumed important drivers of the early-life respiratory microbiota composition. We hypothesized that the respiratory microbiota composition and development in infancy is affecting microbiota stability and thereby resistance against respiratory tract infections (RTIs) over time. Objectives: To investigate common environmental drivers, including birth mode, feeding type, antibiotic exposure, and crowding conditions, in relation to respiratory tract microbiota maturation and stability, and consecutive risk of RTIs over the first year of life. Methods: In a prospectively followed cohort of 112 infants, we characterized the nasopharyngeal microbiota longitudinally from birth on (11 consecutive sample moments and the maximum three RTI samples per subject; in total, n = 1,121 samples) by 16S-rRNA gene amplicon sequencing. Measurements and Main Results: Using a microbiota-based machine-learning algorithm, we found that children experiencing a higher number of RTIs in the first year of life already demonstrate an aberrant microbial developmental trajectory from the first month of life on as compared with the reference group (0-2 RTIs/yr). The altered microbiota maturation process coincided with decreased microbial community stability, prolonged reduction of Corynebacterium and Dolosigranulum, enrichment of Moraxella very early in life, followed by later enrichment of Neisseria and Prevotella spp. Independent drivers of these aberrant developmental trajectories of respiratory microbiota members were mode of delivery, infant feeding, crowding, and recent antibiotic use. Conclusions: Our results suggest that environmental drivers impact microbiota development and, consequently, resistance against development of RTIs. This supports the idea that microbiota form the mediator between early-life environmental risk factors for and susceptibility to RTIs over the first year of life
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