Discovery of phosphorylated lantibiotics with proimmune activity that regulate the oral microbiome.

Lantibiotics are ribosomally synthesized and posttranslationally modified peptides (RiPPs) that are produced by bacteria. Interest in this group of natural products is increasing rapidly as alternatives to conventional antibiotics. Some human microbiome-derived commensals produce lantibiotics to impair pathogens' colonization and promote healthy microbiomes. Streptococcus salivarius is one of the first commensal microbes to colonize the human oral cavity and gastrointestinal tract, and its biosynthesis of RiPPs, called salivaricins, has been shown to inhibit the growth of oral pathogens. Herein, we report on a phosphorylated class of three related RiPPs, collectively referred to as salivaricin 10, that exhibit proimmune activity and targeted antimicrobial properties against known oral pathogens and multispecies biofilms. Strikingly, the immunomodulatory activities observed include upregulation of neutrophil-mediated phagocytosis, promotion of antiinflammatory M2 macrophage polarization, and stimulation of neutrophil chemotaxis-these activities have been attributed to the phosphorylation site identified on the N-terminal region of the peptides. Salivaricin 10 peptides were determined to be produced by S. salivarius strains found in healthy human subjects, and their dual bactericidal/antibiofilm and immunoregulatory activity may provide new means to effectively target infectious pathogens while maintaining important oral microbiota.

Utilizing Oral Neutrophil Counts as an Indicator of Oral Inflammation Associated With Periodontal Disease: A Blinded Multicentre Study.

BACKGROUND: Periodontal diseases are chronic inflammatory conditions that require early screening for effective long-term management. Oral neutrophil counts (ONCs) correlate with periodontal inflammation. This study investigates a point-of-care test using a neutrophil enzyme activity (NEA) colorimetric strip for measuring periodontal inflammation. METHODS: This prospective study had two phases. Phase 1 validated the relationship between ONCs and periodontal inflammation with 90 participants. Phase 2 examined the test's applicability in a real-world setting through a multicentre clinical trial with 375 participants at four sites. ONCs were quantified in oral rinses using laboratory-based methods, and the NEA strip was used for ONC stratification. Clinical measures included bleeding on probing (BoP), probing depth (PD) and clinical attachment loss (CAL). RESULTS: ONCs were significantly elevated in patients with Grade B periodontitis and deep periodontal pockets (PD ≥ 5 mm, CAL ≥ 5 mm). The NEA strip accurately classified patients into high or low ONC categories, showing 80% sensitivity, 82.5% specificity and an AUC of 0.89. It also assessed the effectiveness of periodontal therapy in reducing ONC and inflammation. The test was user-friendly, with no reported discomfort among patients. CONCLUSION: The NEA strip is a user-friendly and rapid screening tool for detecting high ONCs associated with periodontal inflammation and for evaluating the effectiveness of periodontal therapy.

A Primed Neutrophil Subset Predicts the Risk of Bloodstream Infections in Allogeneic Hematopoietic Stem-Cell Transplant Patients: A Prospective Study.

BACKGROUND: Bloodstream infections (BSIs) are the most common infectious complication in patients who receive allogeneic hematopoietic stem-cell transplants (allo-HSCTs). Polymorphonuclear neutrophils (PMNs) are quantified to monitor the susceptibility to BSIs; however, their degree of activation is not. We previously identified a population of primed PMNs (pPMNs) with distinct markers of activation representing approximately 10% of PMNs in circulation. In this study, we investigate whether susceptibility to BSIs is related to the proportion of pPMNs rather than strictly PMN counts. METHODS: In this prospective observational study, we used flow cytometry to assess pPMNs in blood and oral rinse samples collected from patients receiving an allo-HSCT over the course of their treatment. We used the proportion of pPMNs in the blood on day 5 post-transplant to categorize patients into a high- or a low-pPMN group (>10% or <10% pPMNs). These groups were then used as a predictor of BSIs. RESULTS: A total of 76 patients were enrolled in the study with 36 in the high-pPMN group and 40 in the low-pPMN group. Patients in the low-pPMN group had lower expression of PMN activation and recruitment markers and displayed a delay in PMN repopulation of the oral cavity after the transplant. These patients were more susceptible to BSIs compared with patients in the high-pPMN group with an odds ratio of 6.5 (95% confidence interval, 2.110-25.07; P = .002). CONCLUSIONS: In patients who receive an allo-HSCT, having <10% pPMNs early in the post-transplant phase can be an independent predictor of BSI in allo-HSCT patients.

Detecting dental caries on oral photographs using artificial intelligence: A systematic review.

OBJECTIVES: This systematic review aimed at evaluating the performance of artificial intelligence (AI) models in detecting dental caries on oral photographs. METHODS: Methodological characteristics and performance metrics of clinical studies reporting on deep learning and other machine learning algorithms were assessed. The risk of bias was evaluated using the quality assessment of diagnostic accuracy studies 2 (QUADAS-2) tool. A systematic search was conducted in EMBASE, Medline, and Scopus. RESULTS: Out of 3410 identified records, 19 studies were included with six and seven studies having low risk of biases and applicability concerns for all the domains, respectively. Metrics varied widely and were assessed on multiple levels. F1-scores for classification and detection tasks were 68.3%-94.3% and 42.8%-95.4%, respectively. Irrespective of the task, F1-scores were 68.3%-95.4% for professional cameras, 78.8%-87.6%, for intraoral cameras, and 42.8%-80% for smartphone cameras. Limited studies allowed assessing AI performance for lesions of different severity. CONCLUSION: Automatic detection of dental caries using AI may provide objective verification of clinicians' diagnoses and facilitate patient-clinician communication and teledentistry. Future studies should consider more robust study designs, employ comparable and standardized metrics, and focus on the severity of caries lesions.

Validity and reliability of the COVID-19 Anxiety Syndrome Scale in Canadian dentists.

BACKGROUND: The COVID-19 pandemic has resulted in a high level of mental health problems for the population worldwide including healthcare workers. Several studies have assessed these using measurements for anxiety for general populations. The COVID-19 Anxiety Syndrome Scale (C-19ASS) is a self-report measure developed to assess maladaptive forms of coping with COVID-19 (avoidance, threat monitoring and worry) among a general adult population in the United States. We used it in a prospective cohort study of COVID-19 incidence rates in practising Canadian dentists. We therefore need to ensure that it is valid for dentists in French and English languages. This study aimed to evaluate the validity of the C-19ASS in that population. METHODS: Cross-sectional data from the January 2021 monthly follow-up in our prospective cohort study were used. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed. RESULTS: The results of EFA revealed a 2-factor structure solution that explained 47% of the total variance. The CFA showed a good model fit on the data in both English and French languages. The Cronbach's alpha indicated acceptable levels of reliability. Furthermore, the C-19ASS showed excellent divergent validity from the Generalized Anxiety Disorder-7 (GAD-7) scale. CONCLUSIONS: The C-19ASS is valid and reliable instrument to measure COVID-19-related anxiety in English and French among Canadian dentists. PRACTICAL IMPLICATIONS: This validated measure will contribute to understanding of the mental health impact of the pandemic on dentists in Canada and enable the dental regulatory authorities and organizations to intervene to help dentists.

CD301 mediates fusion in IL-4-driven multinucleated giant cell formation.

Multinucleated giant cells (MGCs) are prominent in foreign body granulomas, infectious and inflammatory processes, and auto-immune, neoplastic and genetic disorders, but the molecular determinants that specify the formation and function of these cells are not defined. Here, using tandem mass tag-mass spectrometry, we identified a differentially upregulated protein, C-type lectin domain family 10 member (herein denoted CD301, also known as CLEC10A), that was strongly upregulated in mouse RAW264.7 macrophages and primary murine macrophages undergoing interleukin (IL-4)-induced MGC formation. CD301+ MGCs were identified in biopsy specimens of human inflammatory lesions. Function-inhibiting CD301 antibodies or CRISPR/Cas9 deletion of the two mouse CD301 genes (Mgl1 and Mgl2) inhibited IL-4-induced binding of N-acetylgalactosamine-coated beads by 4-fold and reduced MGC formation by 2.3-fold (P<0.05). IL-4-driven fusion and MGC formation were restored by re-expression of CD301 in the knockout cells. We conclude that in monocytes, IL-4 increases CD301 expression, which mediates intercellular adhesion and fusion processes that are required for the formation of MGCs.This article has an associated First Person interview with the first author of the paper.

Neutrophil Diversity in Health and Disease.

New evidence has challenged the outdated dogma that neutrophils are a homogeneous population of short-lived cells. Although neutrophil subpopulations with distinct functions have been reported under homeostatic and pathological conditions, a full understanding of neutrophil heterogeneity and plasticity is currently lacking. We review here current knowledge of neutrophil heterogeneity and diversity, highlighting the need for deep genomic, phenotypic, and functional profiling of the identified neutrophil subpopulations to determine whether these cells truly represent bona fide novel neutrophil subsets. We suggest that progress in understanding neutrophil heterogeneity will allow the identification of clinically relevant neutrophil subpopulations that may be used in the diagnosis of specific diseases and lead to the development of new therapeutic approaches.

GEF-H1 Is Required for Colchicine Inhibition of Neutrophil Rolling and Recruitment in Mouse Models of Gout.

Gout is a painful arthritic inflammatory disease caused by buildup of monosodium urate (MSU) crystals in the joints. Colchicine, a microtubule-depolymerizing agent that is used in prophylaxis and treatment of acute gout flare, alleviates the painful inflammatory response to MSU crystals. Using i.p. and intra-articular mouse models of gout-like inflammation, we found that GEF-H1/GEF-H1/AHRGEF2, a microtubule-associated Rho-GEF, was necessary for the inhibitory effect of colchicine on neutrophil recruitment. GEF-H1 was required for neutrophil polarization in response to colchicine, characterized by uropod formation, accumulation of F-actin and myosin L chain at the leading edge, and accumulation of phosphorylated myosin L chain, flotillin-2, and P-selectin glycoprotein ligand-1 (PSGL-1) in the uropod. Wild-type neutrophils that were pre-exposed to colchicine failed to roll or accumulate on activated endothelial monolayers, whereas GEF-H1 knockout (GEF-H1-/-) neutrophils were unaffected by treatment with colchicine. In vivo, colchicine blocked MSU-induced recruitment of neutrophils to the peritoneum and the synovium in wild-type mice, but not in GEF-H1-/- mice. Inhibition of macrophage IL-1ß production by colchicine was independent of GEF-H1, supporting a neutrophil-intrinsic mode of action. Our results suggest that the anti-inflammatory effects of colchicine in acute gout-like inflammation can be accounted for by inhibition of neutrophil-rolling interactions with the inflamed vasculature and occurs through GEF-H1-dependent neutrophil stimulation by colchicine. These results contribute to our understanding of the therapeutic action of colchicine, and could inform the application of this drug in other conditions.

Peptidomic Analysis of Urine from Youths with Early Type 1 Diabetes Reveals Novel Bioactivity of Uromodulin Peptides In Vitro.

Chronic hyperglycemia is known to disrupt the proteolytic milieu, initiating compensatory and maladaptive pathways in the diabetic kidney. Such changes in intrarenal proteolysis are captured by the urinary peptidome. To elucidate the early kidney response to chronic hyperglycemia, we conducted a peptidomic investigation into urines from otherwise healthy youths with type 1 diabetes and their non-diabetic peers using unbiased and targeted mass spectrometry-based techniques. This cross-sectional study included two separate cohorts for the discovery (n = 30) and internal validation (n = 30) of differential peptide excretion. Peptide bioactivity was predicted using PeptideRanker and subsequently verified in vitro Proteasix and the Nephroseq database were used to identify putative proteases responsible for peptide generation and examine their expression in diabetic nephropathy. A total of 6550 urinary peptides were identified in the discovery analysis. We further examined the subset of 162 peptides, which were quantified across all thirty samples. Of the 15 differentially excreted peptides (p < 0.05), seven derived from a C-terminal region (589SGSVIDQSRVLNLGPITRK607) of uromodulin, a kidney-specific protein. Increased excretion of five uromodulin peptides was replicated in the validation cohort using parallel reaction monitoring (p < 0.05). One of the validated peptides (SGSVIDQSRVLNLGPI) activated NFκB and AP-1 signaling, stimulated cytokine release, and enhanced neutrophil migration in vitro. In silico analyses highlighted several potential proteases such as hepsin, meprin A, and cathepsin B to be responsible for generating these peptides. In summary, we identified a urinary signature of uromodulin peptides associated with early type 1 diabetes before clinical manifestations of kidney disease and discovered novel bioactivity of uromodulin peptides in vitro Our present findings lay the groundwork for future studies to validate peptide excretion in larger and broader populations, to investigate the role of bioactive uromodulin peptides in high glucose conditions, and to examine proteases that cleave uromodulin.

Canadian dental hygienists' experiences and perceptions of regulatory guidelines during the COVID-19 pandemic: a qualitative descriptive analysis.

BACKGROUND: In Spring of 2020, due to the COVID-19 pandemic, Canadian provincial dental hygiene regulatory bodies implemented new practice guidelines. Reports of stress, anxiety and conflict experienced by dental hygienists have been linked to miscommunication between oral health regulators at this time. Limited data exists on the perceptions and experiences of dental hygienists navigating new guidelines for dental hygiene care during the pandemic. Therefore, the objective of our study was to explore via descriptive thematic analysis how dental hygienists experienced and perceived: i) dental hygiene practice during the COVID-19 pandemic, and ii) their regulatory body's COVID-19 guidelines. METHODS: Participants were identified through provincial dental hygiene licensing bodies. Online bi-monthly questionnaires were administered to participants (n = 876) from December 2021 to January 2022. Two open-ended questions were asked in the questionnaire. A qualitative descriptive thematic analysis was applied to these two questions. RESULTS: Major themes at baseline relayed challenges related to workplace compliance, patient treatment and communication of practice protocols. Across responses, hygienists confirmed conflicting messaging from regulators and guideline interpretations as stressors impacting their professional practice and satisfaction within the profession. Participant responses at endpoint cited increased satisfaction with regulatory guidelines as the pandemic evolved, yet inconsistencies in regulators' messaging was noted as a prevailing issue. CONCLUSION: Inconsistent guideline messaging reflects an increased need for collaboration amongst oral health care regulators to streamline protocols for practice and reduce interprofessional conflict in pandemic circumstances. A national unified approach is warranted in establishing guidelines for dental hygiene practice in Canada.

The Structure and Function of Next-Generation Gingival Graft Substitutes-A Perspective on Multilayer Electrospun Constructs with Consideration of Vascularization.

There is a shortage of suitable tissue-engineered solutions for gingival recession, a soft tissue defect of the oral cavity. Autologous tissue grafts lead to an increase in morbidity due to complications at the donor site. Although material substitutes are available on the market, their development is early, and work to produce more functional material substitutes is underway. The latter materials along with newly conceived tissue-engineered substitutes must maintain volumetric form over time and have advantageous mechanical and biological characteristics facilitating the regeneration of functional gingival tissue. This review conveys a comprehensive and timely perspective to provide insight towards future work in the field, by linking the structure (specifically multilayered systems) and function of electrospun material-based approaches for gingival tissue engineering and regeneration. Electrospun material composites are reviewed alongside existing commercial material substitutes', looking at current advantages and disadvantages. The importance of implementing physiologically relevant degradation profiles and mechanical properties into the design of material substitutes is presented and discussed. Further, given that the broader tissue engineering field has moved towards the use of pre-seeded scaffolds, a review of promising cell options, for generating tissue-engineered autologous gingival grafts from electrospun scaffolds is presented and their potential utility and limitations are discussed.

The Effect of Intensity-Modulated Radiotherapy to the Head and Neck Region on the Oral Innate Immune Response and Oral Microbiome: A Prospective Cohort Study of Head and Neck Tumour Patients.

Neutrophils, also known as polymorphonuclear leukocytes (PMNs), form a significant component of the innate host response, and the consequence of the interaction between the oral microbiota and PMNs is a crucial determinant of oral health status. The impact of radiation therapy (RT) for head and neck tumour (HNT) treatment on the oral innate immune system, neutrophils in particular, and the oral microbiome has not been thoroughly investigated. Therefore, the objective of this study was to characterize RT-mediated changes in oral neutrophils (oPMNs) and the oral microbiome in patients undergoing RT to treat HNTs. Oral rinse samples were collected prior to, during and post-RT from HNT patients receiving RT at Dental Oncology at Princess Margaret Cancer Centre. The oPMNs counts and activation states were analysed using flow cytometry, and the oral microbiome was analysed using 16S rRNA gene sequencing. Statistically significant (p < 0.05) drops in oPMN counts and the activation states of the CD11b, CD16, CD18, CD64 and H3Cit markers from pre-RT to post-RT were observed. Moreover, exposure to RT caused a significant reduction in the relative abundance of commensal Gram-negative bacteria and increased the commensal Gram-positive microbes. Ionizing radiation for the treatment of HNTs simultaneously decreased the recruitment of oPMNs into the oral cavity and suppressed their activation state. The oral microbiome composition post-RT was altered significantly due to RT which may favour the colonization of specific microbial communities unfavourable for the long-term development of a balanced oral microbiome.

Healing effects of monomer and dimer resveratrol in a mouse periodontitis model.

BACKGROUND: The antioxidant and anti-inflammatory effects of resveratrol have been reported previously. Particularly, monomeric trans-resveratrol has been demonstrated to produce positive effects in various pathological processes. We reported previously that resveratrol dimer-rich melinjo extract, among others, caused bone healing, decreased local oxidative damage, and activated antioxidants nuclear factor erythroid 2-related factor 2 (Nrf2) pathways in a mouse model of experimentally induced periodontitis (EP). This study aimed to compare the bone-healing effects of the resveratrol monomer to the resveratrol dimer (gnetin C found in melinjo seed extract) in a model of EP and investigate the involvement of Nrf2 for effects of either form of resveratrol. METHODS: EP was induced experimentally in mice by placement of a 9 - 0 silk ligature around the left second molar. Mice received 10 mg/kg of either resveratrol monomer or dimer intraperitoneally on day 15 after induction of EP. The bone level around the ligated teeth was measured over time, and levels of proinflammatory cytokines and oxidative stress were measured in the periodontal tissues around the ligated teeth. RESULTS: Resveratrol dimer induced greater periodontal bone healing as compared to that related to use of the resveratrol monomer. It appears that healing of periodontal bone in either group was likely related to master regulation of antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) significantly. Downregulation of IL-1ß, a proinflammatory cytokine was also demonstrated in the resveratrol dimer group. CONCLUSION: Our results showed that administration of resveratrol in either dimer form or the monomeric form reduced periodontal bone loss with greater inhibition of bone loss being demonstrated in the dimer group as compared to the monomer group and that these effects were related in all likelihood to decreased oxidative stress and hence reduction in local inflammation.

The role of CRISPR-Cas in advancing precision periodontics.

The significant advancement of molecular biology has revolutionized medicine and provided important technologies to further clinical research development. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) are DNA sequences derived from bacteriophages which have previously infected the bacterial species. The CRISPR-Cas system plays a key role in bacterial defense by detecting and destroying DNA fragments during subsequent bacteriophage invasions. The Cas9 enzyme recognizes and cleaves new invading CRISPR-complementary DNA sequences. Researchers have taken advantage of this biological device to manipulate microbes' genes and develop novel therapeutics to tackle systemic disease. In this review, we discuss the potential of utilizing CRISPR-Cas systems in the periodontal field to develop personalized periodontal care. We summarize promising attempts to bring this technology to the clinical setting. Finally, we provide insights regarding future developments to best utilize the CRISPR-Cas systems to advance precision periodontics. Although further research is imperative to evaluate the safety and potential of using CRISPR-Cas to develop precision periodontics approaches, few studies showed promising data to support the investment into this important technology in the dental sector. CRISPR-Cas9 can be a useful tool to create knockouts in vitro and in vivo as a screening tool to identify cellular pathways involved in the pathogenesis of periodontitis. Alternative CRISPR systems such as CRISPRa, CRISPRi, and Cas13 can be used to modify the transcriptome and gene expression of genes involved in periodontitis progression. CRISPR systems such as Cas3 can be used to target the periodontal biofilm and to develop new strategies to reduce or eliminate periodontal pathogens. Currently, the utility of CRISPR-Cas applications in clinical settings is limited. Through this review, we hope to foster further discussion in the periodontal research and clinical communities with respect to the potential clinical application of novel, CRISPR-Cas based, therapeutics for periodontitis.

Dentists' Experiences and Dental Care in the COVID-19 Pandemic: Insights from Nova Scotia, Canada.

BACKGROUND: This study aimed to describe dental care provision and the perceptions of dentists in Nova Scotia, Canada, during 1 week of the COVID-19 pandemic, shortly after the closing down of non-emergency, in-person care. METHODS: A survey was distributed to all 542 registered dentists in Nova Scotia, asking about dental care provision during 19-25 April 2020. Most answers were categorical, and descriptive analyses of these were performed. Data from the 1 open-ended question were analyzed using an inductive approach to identify themes. RESULTS: The response rate was 43% (n = 235). Most dentists (181) provided care but only 13 provided in-person care. From the open-ended question, 4 concerns emerged: communication from the regulatory authority; respondents' health and that of their staff; the health of and access to care for patients; and the future of their business. CONCLUSION: Most respondents remained engaged in non-in-person dental care using various modes. They expressed concerns about their health and that of their staff and patients as well as about the future of their practice. PRACTICAL IMPLICATIONS: Dentists and dental regulatory authorities should engage in discussions to promote the health of dental staff and patients and quality of care during the chronic phase of the pandemic.

Evaluation of the Online Learning Experience of Dalhousie Dentistry and Dental Hygiene Students during COVID-19 Pandemic Outbreak.

PURPOSE/OBJECTIVE: On 11 March 2020, the World Health Organization declared COVID-19 a pandemic, and universities transitioned to online learning. The objective of this study was to evaluate the experience of students with the online education program offered during the initial phase of the pandemic. METHODS: In April 2020, an anonymous online survey was distributed to 248 undergraduate dental and dental hygiene students in Dalhousie University's faculty of dentistry. The survey contained 10 Likert-type and 3 open-ended questions asking students to evaluate their online learning experience and their preferences regarding in-person and online learning. RESULTS: The response rate was 62.5%. Two-thirds (65.8%) of respondents reported that their educational experience in a virtual setting was very or somewhat positive, while only 14.8% said it was negative or somewhat negative. However, 60.6% agreed or strongly agreed that they preferred face-to-face learning over virtual classroom learning. Students were evenly split on whether online teaching should replace classroom teaching where possible (38.1% agreed/strongly agreed, 39.3% disagreed/strongly disagreed). Analysis of the responses to open-ended questions gave rise to 6 themes: online teaching and assessment methods; helpful online instructor behaviours/traits; advantages of online learning; disadvantages of online learning; combining online and in-person learning; online learning during the pandemic. CONCLUSIONS: Although the sudden transition to online learning was generally well received by students, there still appears to be support for maintaining some form of traditional, face-to-face learning methods in dental education. Students felt that ensuring faculty were creative, understanding and flexible was paramount in the transition to teaching in an online format.

What non-clinical factors influence the general dentist-specialist relationship in Canada?

BACKGROUND: The general dentist-specialist relationship is important for effective patient care and the professional environment. This study explores the non-clinical factors that may influence the general dentist-specialist relationship in Canada. METHODS: A cross-sectional web-based survey of a sample of general dentists across Canada was conducted (N ≈ 11,300). The survey collected information on practitioner (e.g., age, gender, years of practice) and practice (e.g., location, ownership) factors. Two outcomes were assessed: not perceiving specialists as completely collegial and perceiving competitive pressure from specialists. Binary and multivariable logistic regression analysis was conducted. RESULTS: A total of 1328 general dentists responded, yielding a response rate of 11.7%. The strongest associations for perceiving specialists as not completely collegial include being a practice owner (OR = 2.15, 95% CI 1.23, 3.74), working in two or more practices (OR = 1.69, 95% CI 1.07, 2.65), practicing in a small population center (OR = 0.46, 95% CI 0.22, 0.94), and contributing equally to the household income (OR = 0.47, 95% CI 0.26, 0.84). The strongest associations with perceiving medium/large competitive pressure from specialists include having a general practice residency or advanced education in general dentistry (OR = 2.00, 95% CI 1.17, 3.41) and having specialists in close proximity to the practice (OR = 2.52, 95% CI 1.12, 5.69). CONCLUSION: Practitioner and practice factors, mostly related to business and dental care market dynamics, are associated with the potential for strained relationships between general dentists and specialists in Canada. This study points to the need for dental professional organizations to openly discuss the current state of the dental care market, as it has important implications for the profession.

THE PROCESS OF DEVELOPING CONSENSUS GUIDELINES BY DENTAL ONCOLOGISTS FOR PRE-RADIOTHERAPY DENTAL CARE IN HEAD AND NECK CANCER PATIENTS USING THE MODIFIED DELPHI TECHNIQUE.

BACKGROUND: There is a range of pre-radiation therapy (RT) dental care strategies used to prevent the side effects associated with the use of RT in the treatment of head and neck cancer. However, there is a paucity of evidence-based, prospectively tested clinical practice guidelines for dentists to utilize in the provision of care prior to RT. PURPOSE: The aim of this study is to describe the process of creating consensus guidelines for dental care in head and neck cancer patients undergoing RT using the Modified Delphi Technique. PROCEDURE: We invited 44 dental oncologists to participate as panelists in the study. Three rounds of iterative structured surveys were completed within eight months, followed by a virtual meeting to conclude the modified Delphi process. Questions were divided into six main domains and patients were categorized as low, moderate, and high-risk based on factors identified by panelists and agreed upon during the first round. The threshold value set for each round of the Delphi process was a 70% response rate and 75% Consensus level. FINDINGS: Eighteen panelists out of the forty-four (41% overall response rate) completed the study. The number of questions that achieved the set consensus level in rounds 1,2,3 and the virtual meeting were 24%, 62%,61% and 81%, respectively. A confidence level of 95% and a response rate of >75% were reached throughout the process. CONCLUSION: Consensus was attained in most of the questions in all domains, which will be utilized to develop guidelines for dental care in head and neck cancer patients before the commencement of RT.

IL1ß and TNFα promote RANKL-dependent adseverin expression and osteoclastogenesis.

Adseverin is an actin-binding protein involved in osteoclastogenesis, but its role in inflammation-induced bone loss is not well-defined. Here, we examined whether IL1ß and TNFα regulate adseverin expression to control osteoclastogenesis in mouse primary monocytes and RAW264.7 cells. Adseverin was colocalized with subcortical actin filaments and was enriched in the fusopods of fusing cells. In precursor cells, adseverin overexpression boosted the formation of RANKL-induced multinucleated cells. Both IL1ß and TNFα enhanced RANKL-dependent TRAcP activity by 1.6-fold and multinucleated cell formation (cells with ≥3 nuclei) by 2.6- and 3.3-fold, respectively. However, IL1ß and TNFα did not enhance osteoclast formation in adseverin-knockdown cells. RANKL-dependent adseverin expression in bone marrow cells was increased by both IL1ß (5.4-fold) and TNFα (3.3-fold). Luciferase assays demonstrated that this expression involved transcriptional regulation of the adseverin promoter. Activation of the promoter was restricted to a 1118 bp sequence containing an NF-κB binding site, upstream of the transcription start site. TNFα also promoted RANKL-induced osteoclast precursor cell migration. We conclude that IL1ß and TNFα enhance RANKL-dependent expression of adseverin, which contributes to fusion processes in osteoclastogenesis.

An Overview of the Derivation and Function of Multinucleated Giant Cells and Their Role in Pathologic Processes.

Monocyte lineage cells play important roles in health and disease. Their differentiation into macrophages is crucial for a broad array of immunologic processes that regulate inflammation, neoplasia, and infection. In certain pathologic conditions, such as foreign body reactions and peripheral inflammatory lesions, monocytes fuse to form large, multinucleated giant cells (MGCs). Currently, our knowledge of the fusion mechanisms of monocytes and the regulation of MGC formation and function in discrete pathologies is limited. Herein, we consider the types and function of MGCs in disease and assess the mechanisms by which monocyte fusion contributes to the formation of MGCs. An improved understanding of the cellular origins and metabolic functions of MGCs will facilitate their identification and ultimately the treatment of diseases and disorders that involve MGCs.