Search

Species of springtails (Collembola) have a stratified distribution along the soil/air profile and present an opportunity to study adaptive traits relating to a gradient of fluctuating humidity. The habitat of eu-edaphic species (found in deeper litter and soil layers) secures a relatively stable humidity, whereas hemi-edaphic (found in upper litter layers) and epigeic springtails (found on soil surface or vegetation) can experience an increased range of moisture fluctuation with much more rapid shifts between extremes. We hypothesized that the capacity for acclimation to drought conditions is better developed in species associated with the soil surface than in soil-dwelling species. To test this hypothesis, we measured the osmotic response of two epigeic, two hemi-edaphic and three eu-edaphic species to mild drought acclimation (3 d at -1.5 MPa; the average wilting point of plants) and compared the drought tolerance of drought acclimated animals with controls. Epigeic species had no or very little osmotic regulation during mild drought acclimation and unexpectedly became less tolerant to subsequent acute drought stress than controls. The hemi-edaphic and eu-edaphic species significantly increased body fluid osmolality in response to mild drought acclimation. However, none of these species became more drought-tolerant after exposure to mild drought. In conclusion, we found that the osmotic response to drought acclimation was indeed related to the vertical position of a species in the soil/air profile, however, the relationship was opposite to our hypothesis.

N/A

Abstract Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.

The importance of thermal acclimation for the Thermal Death Time (TDT) landscape of the common soil living springtail, Folsomia candida (Collembola, Isotomidae), was investigated. To this aim, we acclimated adult springtails at 10 °C (cold-acclimation) and 20 °C (warm-acclimation), respectively. In static thermal tolerance assays, we found the relationship between survival and exposure time at a number of stressful high and low temperatures. Using logistic modelling, we found, at each exposure temperature, the time until 50% mortality had been reached (Lt50). The exponential functions of TDT curves were found by linear regression of log10 Lt50 values against exposure temperature. Results showed that cold acclimation significantly increased cold tolerance and increased the temperature dependence of cold injury accumulation rate (increased the slope by 4 orders of magnitude) in F. candida. Hence, cold acclimation changed the status of this species from chill-susceptible to moderately chill-tolerant. The cellular injury accumulation at sub-zero temperatures was not related to freezing of body water in this study. Congruently, we found a significant negative effect of cold acclimation on heat tolerance and that cold acclimation decreased the thermal sensitivity of the heat injury accumulation rate. Different slopes of the TDT curves between acclimation groups indicated that acclimation shifted the proportional importance of cellular injury mechanisms or the nature of injury mechanisms. Finally, we compare and combine the TDT curves at extreme high and low temperatures with previously published results on longevity at benign temperatures (from 0 to 30 °C) and describe the full thermal niche of F. candida.

Abstract Antifreeze proteins (AFPs) bind to ice crystals to prevent organisms from freezing. A diversity of AFP folds has been found in fish and insects, including alpha helices, globular proteins, and several different beta solenoids. But the variety of AFPs in flightless arthropods, like Collembola, has not yet been adequately assessed. Here, antifreeze activity was shown to be present in 18 of the 22 species of Collembola from cold or temperate zones. Several methods were used to characterize these AFPs, including isolation by ice affinity purification, MALDI mass spectrometry, amino acid composition analysis, tandem mass spectrometry sequencing, transcriptome sequencing, and bioinformatic investigations of sequence databases. All of these AFPs had a high glycine content and were predicted to have the same polyproline type II helical bundle fold, a fold unique to Collembola. These Hexapods arose in the Ordovician Period with the two orders known to produce AFPs diverging around 400 million years ago during the Andean-Saharan Ice Age. Therefore, it is likely that the AFP arose then and persisted in many lineages through the following two ice ages and intervening warm periods, unlike the AFPs of fish which arose independently during the Cenozoic Ice Age beginning ~ 30 million years ago.

Springtails are omnipresent soil arthropods, vital for ecosystems. In the first global assessment of springtails, this study shows a 20-fold biomass difference between the tundra and the tropics, with distinct temperature-related patterns for diversity and metabolism that suggest climate change may restructure the functioning of soil biodiversity.

Several restoration methods have been developed to aid ecosystem development from highly degraded Icelandic deserts into fully vegetated functional ecosystems. Despite the critical role of soil biota in many key ecosystem processes, the effect of restoration efforts on soil biota has rarely been explored. We took advantage of a large-scale restoration field experiment, to study the effect of distinct revegetation treatments on the taxonomic and functional composition of Collembola communities. Soil samples were taken from plots (one ha. each), that had received functionally distinct revegetation treatments; i: grass + fertilizer, ii: birch seedlings, iii: willow cuttings, iv: lupine and v: control. We were able to show that different revegetation treatments led to the establishment of distinct collembola communities in terms of density and taxonomic and functional composition, 20 years after the revegetation process had started. Life-forms were responsive to revegetation treatment, which suggests that the treatments had induced successional trajectories that lead to distinct habitat conditions, especially with respect to abiotic stress. In contrast to literature, eu-edaphic species were dominating in plots, which were exposed to high levels of disturbance and fluctuations in abiotic conditions. Further research is needed to unravel, to which extent resource supply and abiotic habitat conditions steer Collembola community development across successional trajectories.

Measurement(s) earthworm communities • Abundance • organic material • Diversity • environmental properties Technology Type(s) digital curation Factor Type(s) location Sample Characteristic - Organism Lumbricina Sample Characteristic - Environment soil Sample Characteristic - Location global Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.13399118

Abstract Background and Aim The aims of this study were to describe the prevalence of various oral diseases and to examine the association of the oral diseases with complications and mortality of cirrhosis. Methods A total of 184 cirrhosis patients were enrolled and were followed up for 2 years. They underwent oral clinical and radiographic examination. At study entry, the associations between oral diseases with nutrition, inflammation, and cirrhosis complication status were examined. Then, the associations of oral diseases with all‐cause and cirrhosis‐related mortality were examined using Cox regression to adjust for confounding by age, gender, smoking, alcohol use, alcoholic cirrhosis, cirrhosis complications, comorbidity, Child‐Pugh, and Model of End‐Stage Liver Disease (MELD) score. Results At entry, 26% of the patients had gross caries, 46% periapical lesions, 27% oral mucosal lesions, and 68% periodontitis. Having one or more oral diseases was associated with a higher prevalence of cirrhosis complications (46.7 vs 20.5%), higher C‐reactive protein (28.5 mg/L vs 10.4 mg/L), and higher nutritional risk score (4 vs 3). Two‐thirds of the patients died during follow‐up. The patients with more than one oral disease had an increasingly higher all‐cause mortality (two diseases: hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.02–1.98; three and four diseases: HR 1.75, 95% CI 1.05–3.24) and even higher cirrhosis‐related mortality (two diseases: HR 1.60, 95% CI 1.01–2.40; three and four diseases: HR 2.04, 95% CI 1.05–8.83) compared to those with no oral disease. Conclusion In cirrhosis, having more than one oral disease was associated with more complications and with higher mortality.

The isolated sub-Antarctic islands are of major ecological interest because of their unique species diversity and long history of limited human disturbance. However, since the presence of Europeans, these islands and their sensitive biota have been under increasing pressure due to human activity and associated biological invasions. In such delicate ecosystems, biological invasions are an exceptional threat that may be further amplified by climate change. We examined the invasion trajectory of the blowfly Calliphora vicina (Robineau-Desvoidy 1830). First introduced in the sub-Antarctic Kerguelen Islands in the 1970s, it is thought to have persisted only in sheltered microclimates for several decades. Here, we show that, in recent decades, C. vicina has been able to establish itself more widely. We combine experimental thermal developmental data with long-term ecological and meteorological monitoring to address whether warming conditions help explain its current success and dynamics in the eastern Kerguelen Islands. We found that warming temperatures and accumulated degree days could explain the species’ phenological and long-term invasion dynamics, indicating that climate change has likely assisted its establishment. This study represents a unique long-term view of a polar invader and stresses the rapidly increasing susceptibility of cold regions to invasion under climate change.

Drought tolerance of juvenile and adult life stages is relatively well understood, but very little is known about the tolerance of eggs to drought in this group of animals. The aim of the present study was therefore to investigate the water relations and drought sensitivity of eggs of the hygrophilic springtail, Folsomia candida Willem, 1902 (Isotomidae), exposed to a range of soil water potentials above and below the permanent wilting point of plants (-1.5 MPa). Under saturated conditions, eggs absorbed water during development and increased water content from 1.1 to 2.9 mg mg-1 dry weight. By increasing drought conditions, water absorption was gradually reduced and was nullified approximately at the soil water potential equivalent to the osmolality of egg fluids (630 mOsm corresponding to -1.53 MPa). Eggs had a lower permeability for water (68 ± 13 µg water cm-2 h-1 mm Hg-1) than adults (about 400 µg water cm-2 h-1 mm Hg-1), but eggs were much more sensitive to drought than adults. Eggs did not survive exposure to -1.5 MPa, whereas adults readily survive this level of drought by absorbing water vapour. In conclusion, eggs of F. candida are sensitive to drought and would perish if soil water potential in the field approaches the wilting point of plants, which is often reached during summer droughts. The persistence of this species depends on the survival of post-embryonic life stages.

Background: During periodontal inflammation, bacteria induces chemokine expression and migration of various inflammatory cells. The aim of the study was to learn if periodontal treatment alters salivary concentrations of macrophage activation-related chemokines and if such alterations correlate with abundance of periodontitis-associated bacteria. Methods: Twenty-five patients with periodontitis completed the study (NCT02913248 at clinicaltrials.gov). Periodontal parameters and stimulated saliva samples were obtained at baseline and 2, 6 and 12 weeks after non-surgical periodontal treatment. Salivary concentrations of monocyte chemoattractant proteins (MCP-1-4), macrophage-derived chemokine (MDC), macrophage migration inhibitory factor (MIF), monokine induced by interferon-gamma (MIG), macrophage inflammatory protein (MIP-1α) and interferon-inducible protein (IP-10) were quantified using the Luminex® xMAP™ technique and abundance of bacteria was quantified using next-generation sequencing. Results: The treatment improved all periodontal parameters and caused an increase in the concentrations of MCP-2, MDC and MIP-1α at week 12 compared to baseline, week 2 and week 6, respectively. Salivary concentrations of MCP-1-2, MDC, MIG, MIP-1α and IP-10 correlated with the abundance of specific periodontitis-associated bacteria. Conclusions: Periodontal treatment impacts salivary concentrations of MCP-2, MDC and MIP-1α, which correlate with the abundance of specific periodontitis-associated bacteria. This indicates that these chemokines reflect periodontal status and possess potential in illustrating a response to treatment.

Abstract Liver cirrhosis is a severe disease with major impact on the overall health of the patient including poor oral health. Lately, there has been increasing focus on oral diseases as cirrhosis-related complications due to the potential impact on systemic health and ultimately mortality. Periodontitis is one of the most common oral diseases in cirrhosis patients. However, no studies have investigated the composition of the subgingival microbiome in patients suffering from periodontitis and liver cirrhosis. We analysed the subgingival microbiome in 21 patients with periodontitis and cirrhosis using long-reads Illumina sequencing. The subgingival microbiota was dominated by bacteria belonging to the Firmicutes phylum and to a lesser extend the Actinobacteria and Bacteroidetes phyla. Bacteria usually considered periodontal pathogens, like Porhyromonas ginigivalis, Tannerella forsythia, Treponema denticola, generally showed low abundancy. Comparing the microbiota in our patients with that of periodontitis patients and healthy controls of three other studies revealed that the periodontitis-associated subgingival microbiota in cirrhosis patients is composed of a unique microbiota of bacteria not normally associated with periodontitis. We hypothesise that periodontitis in cirrhosis patients is a consequence of dysbiosis due to a compromised immune system that renders commensal bacteria pathogenic.

Abstract Background Many patients with cirrhosis have poor oral health but little is known on periodontitis, and its clinical significance is largely unknown. This study aimed to examine the prevalence and predictors of periodontitis, and evaluate the association of periodontitis with nutritional and systemic inflammation status. Methods 145 patients with cirrhosis were consecutively enrolled. Clinical, oral examination of plaque, pocket depth, clinical attachment level, and bleeding on probing was performed. Patients were categorized as having no-or-mild, moderate, or severe periodontitis. Predictors of severe periodontitis and the association with nutritional and systemic inflammation status were analyzed using univariable and multivariable logistic regression analyses. Results The large majority of patients had periodontitis, 46% of them severely and 39% moderately. Predictors of severe periodontitis included smoking (odds ratio (OR) 2.93, 95% confidence interval (CI) 1.29–6.63), brushing teeth twice daily (OR 0.30, 95% CI 0.11–0.79), and visiting the dentist annually (OR 3.51, 95% CI 1.22–10.81). Cirrhosis etiology or severity was not predictors of severe periodontitis. The patients with severe periodontitis had a higher nutritional risk score than patients with moderate, mild, or no periodontitis (3, interquartile range (IQR) 3–5 vs. 3, IQR 2–4, P = 0.02). Conclusions Most cirrhosis patients had significant periodontitis, the severity of which was related to life style factors and was associated with higher nutrition risk score. Our results emphasize the need for further research to establish the effect of periodontitis on cirrhosis.

We studied the water balance, body fluid osmolality and survival of the oribatid mite, Pergalumna nervosa, when exposed to drought in field and laboratory experiments. In a replicated field experiment we artificially lowered the soil water content by putting roofs over selected plots, which reduced soil water potential to levels well below the permanent wilting percentage for plants (i.e. below -1.5 MPa). Even though a slight decrease in the abundance of P. nervosa (only found in the 0-5 cm soil layer) was recorded during the most severe drought stress (ca. -3.5 MPa), the majority of adult mites clearly survived these conditions for 3 weeks in the field without migrating to deeper soil layers. Exposing field collected adults in laboratory experiments simulating even more severe drought conditions revealed that P. nervosa can survive several weeks of gradually increasing drought stress (down to -7 MPa) with moderate water loss. The osmolality of body fluids increased as dehydration progressed, but apparently as a result of simple up-concentration of solutes and not the de novo synthesis of protective osmolytes. We compare and discuss these results in the light of what is known about other arthropods.

Objective: To characterize the salivary microbiota of patients with aggressive periodontitis, patients with chronica periodontitis and orally healthy individuals. Methods: A total of 81 unstimulated saliva samples from aggressive periodontitis patients (n = 31), chronic periodontitis patients (n = 25), and orally healthy controls (n = 25) were examined. The V1-V3 region of the 16S rDNA gene was sequenced with Illumina® MiSeqTM, and sequences were annotated to the expanded Human Oral Microbiome Database (eHOMD). Results: A mean percentage of 97.6 (range: 89.8–99.7) of sequences could be identified at species level. Seven bacterial species, including Porphyromonas gingivalis, were identified with significantly higher relative abundance in saliva from aggressive periodontitis patients than in saliva from orally healthy controls. Salivary abundance of P. gingivalis could discriminate aggressive (AUC: 0.80, p = 0.0001) and chronic periodontitis (AUC: 0.72, p = 0.006) from healthy controls. Likewise, salivary presence of P. gingivalis was significantly associated with aggressive (p < 0.0001, RR: 8.1 (95% CI 2.1–31.2)) and chronic periodontitis (p = 0.002, RR: 6.5 (95% CI: 1.6–25.9)). Conclusion: Salivary presence and relative abundance of P. gingivalis associate with aggressive and chronic periodontitis, but do not discriminate between aggressive and chronic periodontitis.

Skinfold assessment is valid and economical; however, it has a steep learning curve, and many programs only include one exposure to the technique. Increasing the number of exposures to skinfold assessment within an undergraduate curriculum would likely increase skill proficiency. The present study combined observational and Think Aloud methodologies to quantify procedural and cognitive characteristics of skinfold assessment. It was hypothesized that 1) increased curricular exposure to skinfold assessment would improve proficiency and 2) the combination of an observational and Think Aloud analysis would provide quantifiable areas of emphasis for instructing skinfold assessment. Seventy-five undergraduates with varied curricular exposure performed a seven-site skinfold assessment on a test subject while expressing their thoughts aloud. A trained practitioner recorded procedural observations, with transcripts generated from audio recordings to capture cognitive information. Skinfold measurements were compared with a criterion value, and bias scores were generated. Participants whose total bias fell within 3.5% of the criterion value were proficient, with the remainder nonproficient. An independent-samples t-test was used to compare procedural and cognitive observations across experience and proficiency groups. Additional curricular exposure improved performance of skinfold assessment in areas such as the measurement of specific sites (e.g., chest, abdomen, and thigh) and procedural (e.g., landmark identification) and cognitive skills (e.g., complete site explanation). Furthermore, the Think Aloud method is a valuable tool for determining curricular strengths and weaknesses with skinfold assessment and as a pedagogical tool for individual instruction and feedback in the classroom.

Lea Ladegaard Grønkjær,1 Palle Holmstrup,2 Søren Schou,3 Kristoffer Schwartz,4 Johanne Kongstad,2 Peter Jepsen,1,5 Hendrik Vilstrup1 1Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, 2Section of Periodontology, Microbiology, and Community Dentistry, Department of Odontology, Faculty of Health and Medical Sciences, 3Section for Oral and Maxillofacial Surgery, Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 4Department of Oral and Maxillofacial Surgery, 5Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark Background: Periapical radiolucency is the radiographic sign of inflammatory bone lesions around the apex of the tooth. We determined the prevalence and predictors of periapical radiolucency in patients with cirrhosis and the association with systemic inflammation status and cirrhosis-related complications.Methods: A total of 110 cirrhosis patients were consecutively enrolled. Periapical radiolucency was defined as the presence of radiolucency or widening of the periapical periodontal ligament space to more than twice the normal width. Predictors of periapical radiolucency and the association with systemic inflammation markers and cirrhosis-related complications were explored by univariable and multivariable logistic regression analyses.Results: Periapical radiolucency was present in one or more teeth in 46% of the patients. Strong predictors were gross caries (odds ratio [OR] 3.12, 95% confidence interval [CI] 1.43–6.79) and severe periodontitis (OR 3.98, 95% CI 1.04–15.20). Also old age (OR 1.10, 95% CI 1.01–1.19) and smoking (OR 3.24, 95% CI 1.02–17.62) were predictors. However, cirrhosis etiology (alcoholic vs nonalcoholic) or severity (Model of End-Stage Liver Disease score) were not predictors. The patients with periapical radiolucency had higher C-reactive protein (15.8 mg/L vs 8.1 mg/L, P=0.02) and lower albumin contents (25 g/L vs 28 g/L, P=0.04) than those without. Furthermore, the patients with periapical radiolucency had a higher prevalence of cirrhosis-related complications such as ascites, hepatic encephalopathy, and/or variceal ­bleeding (46% vs 27%, P=0.05).Conclusion: Periapical radiolucency is often present as an element of poor oral health status and likely has an adverse clinical significance, which should motivate diagnostic and clinical attention to the findings. Keywords: apical periodontitis, cirrhosis, C-reactive protein, inflammation status, MELD score, periapical radiolucency

Background and objective: The microbial profiles of stimulated saliva samples have been shown to differentiate between patients with periodontitis, patients with dental caries, and orally healthy individuals. Saliva was stimulated to allow for easy and rapid collection; however, microbial composition may not reflect the more natural, unstimulated state. The purpose of this study was to validate whether stimulated saliva is an adequate surrogate for unstimulated saliva in determining salivary microbiomes. Design: Unstimulated (n=20) and stimulated (n=20) saliva samples were collected from 20 orally and systemically healthy, non-smoking participants. Salivary bacterial profiles were analyzed by means of the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS), and statistical analysis was performed using Mann–Whitney test with Benjamini–Hochberg's correction for multiple comparison, cluster analysis, principal component analysis, and correspondence analysis. Results: From a total of 40 saliva samples, 496 probe targets were identified with a mean number of targets per sample of 203 (range: 146–303), and a mean number of probe targets of 206 and 200 in unstimulated and stimulated saliva samples, respectively (p=0.62). Based on all statistical methods used for this study, the microbial profiles of unstimulated and stimulated saliva samples collected from the same person were not statistically significantly different. Conclusions: Analysis of bacterial salivary profiles in unstimulated and stimulated saliva samples collected from the same individual showed comparable results. Thus, the results verify that stimulated saliva is an adequate surrogate of unstimulated saliva for microbiome-related studies.

Background and objective: The composition of the salivary microbiota, as determined using various molecular methods, has been reported to differentiate oral health from diseases. Thus, the purpose of this study was to utilize the newly developed molecular technique HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) for comparison of the salivary microbiota in patients with periodontitis, patients with dental caries, and orally healthy individuals. The hypothesis was that this method could add on to the existing knowledge on salivary bacterial profiles in oral health and disease. Design: Stimulated saliva samples (n=30) were collected from 10 patients with untreated periodontitis, 10 patients with untreated dental caries, and 10 orally healthy individuals. Salivary microbiota was analyzed using HOMINGS and statistical analysis was performed using Kruskal–Wallis test with Benjamini–Hochberg's correction. Results: From a total of 30 saliva samples, a mean number of probe targets of 205 (range 120–353) were identified, and a statistically significant higher mean number of targets was registered in samples from patients with periodontitis (mean 220, range 143–306) and dental caries (mean 221, range 165–353) as compared to orally healthy individuals (mean 174, range 120–260) (p=0.04 and p=0.04). Nine probe targets were identified with a different relative abundance between groups (p

Bacterial profiles of saliva in subjects with periodontitis and dental caries have been demonstrated to differ from that of oral health. The aim of this comparative analysis of existing data generated by the Human Oral Microbe Identification Microarray (HOMIM) from 293 stimulated saliva samples was to compare bacterial profiles of saliva in subjects with periodontitis and dental caries.

Objective: Clients often have limited time in a nutrition education setting. An improved understanding of the strategies used to accurately estimate calories may help to identify areas of focused instruction to improve nutrition knowledge. Methods: A "Think Aloud" exercise was recorded during the estimation of calories in a standard dinner meal (415 kcal) in 15 nutrition-trained and 15 untrained subjects. Accuracy of participant estimation was assessed, and estimation strategies were compared in accurate vs inaccurate estimators. Results: Accurate participants were more likely to demonstrate an ability to convert between common portion size measurements and serving sizes, possess some knowledge of energy density, and properly implement basic math skills. Conclusions and Implications: The ''Think Aloud'' methodology was informative in assessing the cognitive processes behind a nutrition exercise, and further use is warranted. Focused instruction in portion size conversion, energy density, and the use of math skills may enhance calorie estimation accuracy. (Contains 2 tables.)

Background: Cytokine‐producing B cells play a well‐established role in modifying immune responses in chronic inflammatory diseases. We characterized B‐cell cytokine responses against periodontitis‐associated bacteria in patients with periodontitis. Methods: Blood and saliva samples were collected from patients with periodontitis grade B (N = 31) or grade C (N = 25), and 25 healthy controls (HCs). Mononuclear cells were stimulated with Porphyromonas gingivalis, Fusobacterium nucleatum, Staphylococcus epidermidis, or Cutibacterium acnes, and B‐cell production of tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, interferon (IFN)‐γ, IL‐10 and transforming growth factor (TGF)‐β by B cells was assessed by flow cytometry. Results: HCs had higher baseline frequencies of B cells producing IFN‐γ or TNF‐α than grade B patients, but only B cells from grade B patients showed significant differentiation into IFN‐γ‐, TNF‐α‐, TGF‐β‐, or IL‐10‐producing cells after challenge with P. gingivalis and into IFN‐γ‐, TGF‐β‐, or IL‐10‐producing cells after challenge F. nucleatum. Notably, the baseline frequency of IL‐10‐producing B cells from grade C patients correlated inversely with clinical attachment loss (AL). The major proportion of the IFN‐γ‐ and TGF‐β‐producing B cells were CD27+ memory cells, while the IL‐10‒producing B cells were mainly CD27−CD5−. Conclusions: B cells from grade B patients, particularly those harboring P. gingivalis, showed proinflammatory B‐cell responses to P. gingivalis. Moreover, the baseline frequency of IL‐10‐producing B cells in the grade C group correlated inversely with AL, suggesting a diminished immunoregulatory capacity of IL‐10‒producing B cells in these patients. [ABSTRACT FROM AUTHOR]

Salivary protein levels have been studied in periodontitis. However, there is lack of information on salivary cytokine levels in early gingival inflammation. The aim of this study was to determine salivary levels of vascular endothelial growth factor (VEGF), interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, IL-1β, and IL-1 receptor antagonist (IL-1Ra) in gingival inflammation. Twenty-eight systemically and orally healthy nonsmokers abstained from oral hygiene protocols for 10 days. After that, self-performed cleaning was resumed for 14 days. Plaque and gingival indexes were measured, and saliva samples were collected at days 1, 4, 7, 10, and 24. Salivary cytokines were detected with Luminex®-xMAP™. Salivary IL-1β, IL-1Ra, and VEGF levels decreased after 10 days’ development of experimental gingivitis and reached baseline levels at the end of the 2-week resolution period. Salivary IL-8 levels decreased and remained low during development and resolution of experimental gingivitis. Initial inflammation in gingival tissues is associated with a decrease in inflammatory cytokines in saliva. Further studies are needed to evaluate if inflammatory cytokines bind to their functional receptors within the gingival tissue during early gingivitis, which may limits their spillover to the gingival crevice and ultimately saliva.

Objectives: The aim was to elucidate whether levels of circulating antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis correlate to loss of attachment, as a marker for periodontitis and cardiovascular disease (CVD). Design: Sera were collected from 576 participants of the Danish Health Examination Survey (DANHES). Immunoglobulin G antibodies against lipopolysaccharide (LPS) and protein antigens from the a, b and c serotypes of A. actinomycetemcomitans and P. gingivalis were quantified by titration in ELISA plates coated with a mixture of antigens prepared by disintegration of bacteria. Results: Levels of antibodies against P. gingivalis (OR = 1.48) and A. actinomycetemcomitans (1.31) associated with periodontitis, as determined by univariable logistic regression analysis. These antibody levels also associated with CVD (1.17 and 1.37), respectively, However, after adjusting for other risk factors, including age, smoking, gender, alcohol consumption, overweight, and level of education using multivariable logistic regression analysis, only increasing body mass index (BMI; 1.09), previous smoking (1.99), and increasing age (decades) (2.27) remained associated with CVD. Increased levels of antibodies against P. gingivalis (1.34) remained associated with periodontitis after adjusting for other risk factors. Conclusions: CVD and periodontitis were associated with levels of IgG antibodies to P. gingivalis or A. actinomycetemcomitans in univariable analyses, but only the association of P. gingivalis antibody levels with periodontitis reached statistical significance after adjustment for common confounders. Age, in particular, influenced this relationship.

Cholesterol deposits and pro-inflammatory cytokines play an essential role in the pathogenesis of atherosclerosis, a predominant cause of cardiovascular disease (CVD). Epidemiological evidence has linked periodontal disease (PD) with atherosclerotic CVD. Accordingly, viable periodontal pathogens, including Porphyromonas gingivalis, have been found in atherosclerotic plaques in humans and mice. We aimed to determine whether cholesterol crystals (CHCs) and oral bacteria synergize in the stimulation of human monocytes. Incubation of human monocytes with CHCs induced secretion of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, and IL-8. Moreover, CHCs markedly enhanced secretion of IL-1β by monocytes stimulated with the toll-like receptor (TLR) 4 agonist Escherichia coli lipopolysaccharide (LPS), and the TLR2 agonist Staphylococcus aureus lipoteichoic acid. Notably, CHCs also enhanced IL-1β secretion induced by P. gingivalis LPS and IL-1β secretion induced by whole P. gingivalis bacteria. This enhancement was abrogated by the NLRP3 inflammasome inhibitors Z-YVAD-FMK and glibenclamide. CHCs had no effect on cytokine production induced by P. gingivalis gingipains. Taken together, our findings support that CHCs, via stimulation of NLRP3 inflammasomes, act in synergy with the periodontal pathogen P. gingivalis to promote monocyte secretion of pro-atherogenic cytokines.

This study compared salivary bacterial profiles in two groups having a 10-fold difference in levels of caries experience, as it was hypothesized that the composition of the salivary microbiota might associate with the levels of caries experience. Bacterial profiles in stimulated saliva samples from 85 individuals with low levels of caries experience (healthy group) and 79 individuals with high levels of caries experience (caries group) were analyzed by means of the Human Oral Microbiome Identification Next Generation Sequencing (HOMINGS) technique. Subsequently, saliva samples from caries-free individuals in the healthy group (n = 57) and the caries group (n = 31) were compared. A significantly higher α-diversity (p

The purpose of this study was to compare microbial profiles of saliva, pooled and site-specific subgingival samples in patients with periodontitis. We tested the hypotheses that saliva can be an alternative to pooled subgingival samples, when screening for presence of periopathogens.Site specific subgingival plaque samples (n = 54), pooled subgingival plaque samples (n = 18) and stimulated saliva samples (n = 18) were collected from 18 patients with generalized chronic periodontitis. Subgingival and salivary microbiotas were characterized by means of HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) and microbial community profiles were compared using Spearman rank correlation coefficient.Pronounced intraindividual differences were recorded in site-specific microbial profiles, and site-specific information was in general not reflected by pooled subgingival samples. Presence of Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Filifactor alocis, Tannerella forsythia and Parvimona micra in site-specific subgingival samples were detected in saliva with an AUC of 0.79 (sensitivity: 0.61, specificity: 0.94), compared to an AUC of 0.76 (sensitivity: 0.56, specificity: 0.94) in pooled subgingival samples.Site-specific presence of periodontal pathogens was detected with comparable accuracy in stimulated saliva samples and pooled subgingival plaque samples. Consequently, saliva may be a reasonable surrogate for pooled subgingival samples when screening for presence of periopathogens. Future large-scale studies are needed to confirm findings from this study.

Increasing evidence has suggested an independent association between periodontitis and a range of comorbidities, for example cardiovascular disease, type 2 diabetes, rheumatoid arthritis, osteoporosis, Parkinson’s disease, Alzheimer’s disease, psoriasis, and respiratory infections. Shared inflammatory pathways are likely to contribute to this association, but distinct causal mechanisms remain to be defined. Some of these comorbid conditions may improve by periodontal treatment, and a bidirectional relationship may exist, where, for example, treatment of diabetes can improve periodontal status. The present article presents an overview of the evidence linking periodontitis with selected systemic diseases and calls for increased cooperation between dentists and medical doctors to provide optimal screening, treatment, and prevention of both periodontitis and its comorbidities.