Acute coronavirus infection triggers a TNF-dependent osteoporotic phenotype in mice.

AIMS: Millions of people died during the COVID-19 pandemic, but the vast majority of infected individuals survived. Now, some consequences of the disease, known as long COVID, are been revealed. Although the respiratory system is the target of Sars-CoV-2, COVID-19 can influence other parts of the body, including bone. The aim of this work was to investigate the impact of acute coronavirus infection in bone metabolism. MAIN METHODS: We evaluated RANKL/OPG levels in serum samples of patients with and without acute COVID-19. In vitro, the effects of coronavirus in osteoclasts and osteoblasts were investigated. In vivo, we evaluated the bone phenotype in a BSL2 mouse model of SARS-like disease induced by murine coronavirus (MHV-3). KEY FINDINGS: Patients with acute COVID-19 presented decreased OPG and increased RANKL/OPG ratio in the serum versus healthy individuals. In vitro, MHV-3 infected macrophages and osteoclasts, increasing their differentiation and TNF release. Oppositely, osteoblasts were not infected. In vivo, MHV-3 lung infection triggered bone resorption in the femur of mice, increasing the number of osteoclasts at 3dpi and decreasing at 5dpi. Indeed, apoptotic-caspase-3+ cells have been detected in the femur after infection as well as viral RNA. RANKL/OPG ratio and TNF levels also increased in the femur after infection. Accordingly, the bone phenotype of TNFRp55-/- mice infected with MHV-3 showed no signs of bone resorption or increase in the number of osteoclasts. SIGNIFICANCE: Coronavirus induces an osteoporotic phenotype in mice dependent on TNF and on macrophage/osteoclast infection.

Type IV hypersensitivity associated with restorative materials: Clinical report and systematic literature review.

STATEMENT OF PROBLEM: Type IV hypersensitivity reactions (Type IV HR) are immune responses mediated by antigen-specific effector T cells. PURPOSE: The purpose of this clinical report and systematic review was to report the clinicopathological features of Type IV HR in the oral mucosa and to present a systematic literature review of case reports and case series of individuals with Type IV HR in the oral mucosa related to contact with dental materials. MATERIAL AND METHODS: The presented clinical lesions were melanotic macules with burning that affected the internal labial mucosa in contact with composite resin veneer crowns. Histopathological and immunohistochemical analysis of the lesion was performed. The systematic literature review was performed based on a search in 4 electronic databases (PubMed/MEDLINE, Scopus, Web of Science, and Ovid). RESULTS: Immunohistochemistry showed positivity for CD4, CD8, CD20, CD3, tryptase, and CD117. After conservative treatment, the patient reported improvement of symptoms, and a decrease in the number of inflammatory cells was verified. Twenty-one articles were included in the review. Unlike the present patient, the authors of all the articles recommended radical treatment with the removal of the dental material. CONCLUSIONS: Type IV HR in oral mucosa is rare, and the assessment of clinical and histopathological characteristics is essential to perform an accurate diagnosis and provide appropriate treatment.

Direct oral anticoagulants in oral surgery: a prospective cohort.

BACKGROUND: Quantitative assessment of bleeding in dental extractions is rarely reported in the literature. The assessment of bleeding might provide additional evidence to predict and minimize postoperative outcomes. The aim of this study was to evaluate the pattern of bleeding in individuals taking direct oral anticoagulants (DOACs) submitted to dental extractions. METHODS: Intraoperative bleeding was evaluated by using total collected bleeding corrected by absorbance reading (dental bleeding score). To monitoring bleeding episodes from the day of surgery, this cohort was followed up until the seventh postoperative day. RESULTS: Forty-five procedures were performed in three comparative groups, patients under DOACs, individuals taking vitamin K antagonists (VKAs) and without anticoagulant therapy. No bleeding events were observed in procedures carried out in individuals of the DOAC group. Additional hemostatic measures were required in two procedures in the VKA group and one in the non-anticoagulated group. The dental bleeding scores obtained for the DOAC and VKA groups were similar. CONCLUSIONS: Our data suggest that the DOAC therapy did not result in increased bleeding outcomes in this sample.

Dental management for patients undergoing heart valve surgery.

This study sought to review current guidelines and the most optimal dental management for patients undergoing cardiac valve surgery.