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| 2. |
- Laheij, Amga, et al.
(author)
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Microbial changes in relation to oral mucositis in autologous hematopoietic stem cell transplantation recipients
- 2019
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
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Journal article (peer-reviewed)abstract
- The aim of this prospective, two center study was to investigate the dynamics of the microbial changes in relation to the development of ulcerative oral mucositis in autologous SCT (autoSCT) recipients. Fifty-one patients were diagnosed with multiple myeloma and treated with high-dose melphalan followed by autoSCT. They were evaluated before, three times weekly during hospitalization, and three months after autoSCT. At each time point an oral rinse was collected and the presence or absence of ulcerative oral mucositis (UOM) was scored (WHO scale). Oral microbiome was determined by using 16S rRNA amplicon sequencing and fungal load by qPCR. Twenty patients (39%) developed UOM. The oral microbiome changed significantly after autoSCT and returned to pre-autoSCT composition after three months. However, changes in microbial diversity and similarity were more pronounced and rapid in patients who developed UOM compared to patients who did not. Already before autoSCT, different taxa discriminated between the 2 groups, suggesting microbially-driven risk factors. Samples with high fungal load (>0.1%) had a significantly different microbial profile from samples without fungi. In conclusion, autoSCT induced significant and reversible changes in the oral microbiome, while patients who did not develop ulcerative oral mucositis had a more resilient microbial ecosystem.
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| 3. |
- van Leeuwen, S. J. M., et al.
(author)
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Significant salivary changes in relation to oral mucositis following autologous hematopoietic stem cell transplantation
- 2021
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In: Bone Marrow Transplantation. - : Springer Science and Business Media LLC. - 0268-3369 .- 1476-5365.
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Journal article (peer-reviewed)abstract
- The aim of this multicentre, longitudinal study was to determine salivary changes in relation to oral mucositis (OM) in multiple myeloma patients following high-dose melphalan and autologous hematopoietic stem cell transplantation (ASCT). Unstimulated and stimulated whole-mouth saliva samples (UWS and SWS) were collected before ASCT, 1x/wk during the hospitalisation phase, and 3 and 12 months post-ASCT. During the hospitalisation period OM was scored 3x/wk (WHO system). Flow rate, pH, total protein concentration (Nanodrop), albumin, lactoferrin, neutrophil defensin-1 (HNP1), total IgA and S100A8/A9 (ELISA) were determined. Mixed models were used to evaluate differences between ulcerative (u)OM (>= 2 WHO, n = 20) and non-uOM (n = 31) groups. Until 18 days after ASCT, flow rate, pH, total IgA and HNP1 levels decreased in UWS and/or SWS, while log lactoferrin levels were significantly increased (UWS: p = 0.016 95% CI [0.36, 3.58], SWS: p < 0.001 95% CI [1.14, 3.29]). Twelve months post-ASCT, salivary protein levels were similar to baseline except for log total IgA, which was higher (UWS: p < 0.001 95% CI [0.49, 1.29], SWS: p < 0.001 95% CI [0.72, 1.45]). No differences between uOM and non-uOM groups were observed. Changes in salivary proteins indicated an inflammatory reaction in salivary glands coinciding with mucosal and systemic reactions in response to high-dose melphalan.
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| 4. |
- Bulthuis, M. S., et al.
(author)
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Caries Progression after Haematopoietic Stem Cell Transplantation and the Role of Hyposalivation
- 2022
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In: Caries Research. - : S. Karger AG. - 0008-6568 .- 1421-976X. ; 56:3, s. 187-196
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Journal article (peer-reviewed)abstract
- Haematopoietic stem cell transplantation (HSCT) preceded by a conditioning regimen is an established treatment option for many haematological diseases. Decreased salivary flow rates after HSCT may increase caries risk. We aim to estimate the extent to which caries lesions develop or progress in adult HSCT recipients and assess its association with salivary flow rates. A multi-centre prospective observational study was conducted in which patients receiving HSCT were followed up for 18 months. We included 116 patients (median age 56 years, 43% female) from two medical centres in the Netherlands. Unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) were collected, and full caries charts were made before HSCT and 3, 6, 12, and 18 months post-HSCT. Caries was scored according to the ICDAS criteria by trained dentist-examiners. New dentine lesions or lesion progression into dentine (ICDAS >= 4 or cavitated root lesions) occurred in 32% of patients over 18 months. The median number of affected surfaces was 2 (range: 1-12) per patient with caries progression. The influence of hyposalivation of unstimulated saliva (<0.2 mL/min) and stimulated saliva (<0.7 mL/min) at baseline and after 3 months on caries progression was determined with a negative binomial regression model. Hyposalivation of SWS 3 months after HSCT was a significant risk indicator for caries progression (incidence rate ratio: 5.30, 95% CI: 2.09-13.4, p < 0.001), while hyposalivation of SWS at baseline and hyposalivation of UWS were not. We conclude that caries progression is a common oral complication in patients after HSCT, and stimulated hyposalivation shortly after treatment is a significant risk indicator for caries progression.
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| 5. |
- Bulthuis, M. S., et al.
(author)
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The effect of conditioning regimen and prescribed medications on hyposalivation in haematopoietic cell transplantation (HCT) patients: an 18-month prospective longitudinal study
- 2023
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In: Clinical Oral Investigations. - 1432-6981. ; 27, s. 7369-7381
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Journal article (peer-reviewed)abstract
- Objectives Haematopoietic cell transplantation (HCT) preceded by a conditioning regimen is an established treatment option for (non)malignant haematologic disorders. We aim to describe the development of hyposalivation over time in HCT recipients, and determine risk indicators.Materials and methods A multi-centre prospective longitudinal observational study was conducted. Unstimulated (UWS) and stimulated (SWS) whole saliva was collected before HCT, early post-HCT, and after 3, 6, 12, and 18 months. The effect of type of transplantation (allogeneic vs autologous) and intensity (full vs reduced) of the conditioning regimen on hyposalivation (UWS < 0.2 mL/min; SWS < 0.7 mL/min) was explored.Results A total of 125 HCT recipients were included. More than half of the patients had hyposalivation early post-HCT; a quarter still had hyposalivation after 12 months. The conditioning intensity was a risk indicator in the development of hyposalivation of both UWS (OR: 3.9, 95% CI: 1.6-10.6) and SWS (OR: 8.2, 95% CI: 2.9-24.6). After 3 and 12 months, this effect was not statistically significant anymore.Conclusions Hyposalivation affects the majority of patients early post-HCT. The conditioning intensity and the type of transplantation were significant risk indicators in the development of hyposalivation. The number of prescribed medications, total body irradiation as part of the conditioning regimen and oral mucosal graft-versus-host disease did not influence hyposalivation significantly.
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| 6. |
- Cornelissen, Johannes H C, et al.
(author)
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Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes
- 2007
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In: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 10:7, s. 619-627
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Journal article (peer-reviewed)abstract
- Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide.Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.
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| 7. |
- Laheij, Amga, et al.
(author)
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Long-Term Analysis of Resilience of the Oral Microbiome in Allogeneic Stem Cell Transplant Recipients
- 2022
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In: Microorganisms. - : MDPI AG. - 2076-2607. ; 10:4
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Journal article (peer-reviewed)abstract
- Stem cell transplantation (SCT) is associated with oral microbial dysbiosis. However, long-term longitudinal data are lacking. Therefore, this study aimed to longitudinally assess the oral microbiome in SCT patients and to determine if changes are associated with oral mucositis and oral chronic graft-versus-host disease. Fifty allogeneic SCT recipients treated in two Dutch university hospitals were prospectively followed, starting at pre-SCT, weekly during hospitalization, and at 3, 6, 12, and 18 months after SCT. Oral rinsing samples were taken, and oral mucositis (WHO score) and oral chronic graft-versus-host disease (NIH score) were assessed. The oral microbiome diversity (Shannon index) and composition significantly changed after SCT and returned to pre-treatment levels from 3 months after SCT. Oral mucositis was associated with a more pronounced decrease in microbial diversity and with several disease-associated genera, such as Mycobacterium, Staphylococcus, and Enterococcus. On the other hand, microbiome diversity and composition were not associated with oral chronic graft-versus-host disease. To conclude, dysbiosis of the oral microbiome occurred directly after SCT but recovered after 3 months. Diversity and composition were related to oral mucositis but not to oral chronic graft-versus-host disease.
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| 8. |
- Rozema, J, et al.
(author)
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The role of UV-B radiation in aquatic and terrestrial ecosystems—an experimental and functional analysis of the evolution of UV-absorbing compounds
- 2002
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In: Journal of Photochemistry and Photobiology, B: Biology. - 1011-1344. ; 66:1, s. 2-12
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Journal article (peer-reviewed)abstract
- We analysed and compared the functioning of UV-B screening pigments in plants from marine, fresh water and terrestrial ecosystems, along the evolutionary line of cyanobacteria, unicellular algae, primitive multicellular algae, charophycean algae, lichens, mosses and higher plants, including amphibious macrophytes. Lichens were also included in the study. We were interested in the following key aspects: (a) does the water column function effectively as an ‘external UV-B filter’?; (b) do aquatic plants need less ‘internal UV-B screening’ than terrestrial plants?; (c) what role does UV screening play in protecting the various plant groups from UV-B damage, such as the formation of thymine dimers?; and (d) since early land ‘plants’ (such as the predecessors of present-day cyanobacteria, lichens and mosses) experienced higher UV-B fluxes than higher plants, which evolved later, are primitive aquatic and land organisms (cyanobacteria, algae, lichens, mosses) better adapted to present-day levels of UV-B than higher plants? Furthermore, polychromatic action spectra for the induction of UV screening pigments of aquatic organisms have been determined. This is relevant for translating ‘physical’ radiation measurements of solar UV-B into ‘biological’ and ‘ecological’ effects. From the action spectra, radiation amplification factors (RAFs) have been calculated. These action spectra allow us to determine any mitigating or antagonistic effects in the ecosystems and therefore qualify the damage prediction for the ecosystems under study. We summarize and discuss the main results based on three years of research of four European research groups. The central theme of the work was the investigation of the effectiveness of the various screening compounds from the different species studied in order to gain some perspective of the evolutionary adaptations from lower to higher plant forms. The induction of mycosporine-like amino acids (MAAs) was studied in the marine dinoflagellate Gyrodinium dorsum, the green algal species Prasiola stipitata and in the cyanobacterium Anabaena sp. While visible (400–700 nm) and long wavelength UV-A (315–400 nm) showed only a slight effect, MAAs were effectively induced by UV-B (280–315 nm). The growth of the lower land organisms studied, i.e. the lichens Cladina portentosa, Cladina foliacaea and Cladonia arbuscula, and the club moss Lycopodiumannotinum, was not significantly reduced when grown under elevated UV-B radiation (simulating 15% ozone depletion). The growth in length of the moss Tortula ruralis was reduced under elevated UV-B. Of the aquatic plants investigated the charophytes Chara aspera showed decreased longitudinal growth under elevated UV-B. In the ‘aquatic higher plants’ studied, Ceratophyllum demersum, Batrachium trichophyllum and Potamogeton alpinus, there was no such depressed growth with enhanced UV-B. In Chara aspera, neither MAAs nor flavonoids could be detected. Of the terrestrial higher plants studied, Fagopyrum esculentum, Deschampsia antarctica, Vicia faba, Calamagrostis epigejos and Carex arenaria, the growth of the first species was depressed with enhanced UV-B, in the second species length growth was decreased, but the shoot number was increased, and in the latter two species of a dune grassland there was no reduced growth with enhanced UV-B. In the dune grassland species studied outdoors, at least five different flavonoids appeared in shoot tissue. Some of the flavonoids in the monocot species, which were identified and quantified with HPLC, included orientin, luteolin, tricin and apigenin. A greenhouse study with Vicia faba showed that two flavonoids (aglycones) respond particularly to enhanced UV-B. Of these, quercetin is UV-B inducible and mainly located in epidermal cells, while kaempferol occurs constitutively. In addition to its UV-screening function, quercetin may also act as an antioxidant. Polychromatic action spectra were determined for induction of the UV-absorbing pigments in three photosynthetic organisms, representing very different taxonomic groups and different habitats. In ultraviolet photobiology, action spectra mainly serve two purposes: (1) identification of the molecular species involved in light absorption; and (2) calculation of radiation amplification factors for assessing the effect of ozone depletion. Radiation amplification factors (RAFs) were calculated from the action spectra. In a somewhat simplified way, RAF can be defined as the percent increase of radiation damage for a 1% depletion of the ozone layer. Central European summer conditions were used in the calculations, but it has been shown that RAF values are not critically dependent on latitude or season. If only the ultraviolet spectral region is considered, the RAF values obtained are 0.7 for the green alga Prasiola stipitata, 0.4 for the dinoflagellate Gyrodinium dorsum, and 1.0 for the cyanobacterium Anabaena sp. In the case of P. stipitata, however, the effect of visible light (PAR, photosynthetically active radiation, 400–700 nm) is sufficient to lower the RAF to about 0.4, while the PAR effect for G. dorsum is negligible. RAFs for some damage processes, such as for DNA damage (RAF=2.1 if protective effects or photorepair are not considered [1]), are higher than those above. Our interpretation of this is that if the ozone layer is depleted, increased damaging radiation could overrule increased synthesis of protective pigments. In addition to investigating the functional effectiveness of the different screening compounds, direct UV effects on a number of key processes were also studied in order to gain further insight into the ability of the organisms to withstand enhanced UV-B radiation. To this end, the temperature-dependent repair of cyclobutane dimers (CPD) and (6–4) photoproducts induced by enhanced UV-B was studied in Nicotiana tabacum, and the UV-B induction of CPD was studied in the lichen Cladonia arbuscula [2]. Also, photosynthesis and motility were monitored and the response related to the potential function of the screening compounds of the specific organism.
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| 9. |
- Skallsjö, Kristina, 1976, et al.
(author)
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Oral health in patients scheduled for hematopoietic stem cell transplantation in the Orastem study
- 2023
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In: Plos One. - 1932-6203. ; 18:5
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Journal article (peer-reviewed)abstract
- Despite advances in transplant medicine, prevalence of complications after hematopoietic stem cell transplantation (HSCT) remains high. The impact of pre-HSCT oral health factors on the incidence and severity of complications post-HSCT is poorly understood. The aim of this prospective, observational study was to analyze oral health in patients planned for HSCT. Patients >= 18 years requiring HSCT were included from five sites between 2011-2018. General health, oral findings and patient-reported symptoms were registered in 272 patients. Oral symptoms around disease onset were reported by 43 patients (15.9%) and 153 patients (58.8%) reported oral complications during previous chemotherapy. One third of patients experienced oral symptoms at the oral examination before conditioning regimen and HSCT. In total, 124 (46.1%) patients had dental caries, 63 (29.0%) had >= one tooth with deep periodontal pockets, 147 (75.0%) had >= one tooth with bleeding on probing. Apical periodontitis was observed in almost 1/4 and partially impacted teeth in 17 (6.3%) patients. Oral mucosal lesions were observed in 84 patients (30.9%). A total of 45 (17.4%) of 259 patients had at least one acute issue to be managed prior to HSCT. In conclusion, oral symptoms and manifestations of oral disease were prevalent in patients planned for HSCT. The extent of oral and acute dental diseases calls for general oral screening of patients pre-HSCT.
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| 10. |
- van Leeuwen, S. J. M., et al.
(author)
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The salivary proteome in relation to oral mucositis in autologous hematopoietic stem cell transplantation recipients: a labelled and label-free proteomics approach
- 2023
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In: Bmc Oral Health. - 1472-6831. ; 23:1
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Journal article (peer-reviewed)abstract
- BackgroundOral mucositis is a frequently seen complication in the first weeks after hematopoietic stem cell transplantation recipients which can severely affects patients quality of life. In this study, a labelled and label-free proteomics approach were used to identify differences between the salivary proteomes of autologous hematopoietic stem cell transplantation (ASCT) recipients developing ulcerative oral mucositis (ULC-OM; WHO score & GE; 2) or not (NON-OM).MethodsIn the TMT-labelled analysis we pooled saliva samples from 5 ULC-OM patients at each of 5 timepoints: baseline, 1, 2, 3 weeks and 3 months after ASCT and compared these with pooled samples from 5 NON-OM patients. For the label-free analysis we analyzed saliva samples from 9 ULC-OM and 10 NON-OM patients at 6 different timepoints (including 12 months after ASCT) with Data-Independent Acquisition (DIA). As spectral library, all samples were grouped (ULC-OM vs NON-OM) and analyzed with Data Dependent Analysis (DDA). PCA plots and a volcano plot were generated in RStudio and differently regulated proteins were analyzed using GO analysis with g:Profiler.ResultsA different clustering of ULC-OM pools was found at baseline, weeks 2 and 3 after ASCT with TMT-labelled analysis. Using label-free analysis, week 1-3 samples clustered distinctly from the other timepoints. Unique and up-regulated proteins in the NON-OM group (DDA analysis) were involved in immune system-related processes, while those proteins in the ULC-OM group were intracellular proteins indicating cell lysis.ConclusionsThe salivary proteome in ASCT recipients has a tissue protective or tissue-damage signature, that corresponded with the absence or presence of ulcerative oral mucositis, respectively.
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