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BACKGROUND: Endoscopic removal with forceps/baskets is favored in treating submandibular stones due to its minimal invasiveness. However, recent studies have found that endoscopic removal failure (ERF) is not unusual, and stones in such cases still need to be removed with other surgical methods. If the risk of ERF can be predicted preoperatively, it could be helpful for surgeons when choosing the appropriate therapy. AIM: To develop a predictive nomogram for the risk of ERF when treating submandibular stones based on their preoperative clinical features. METHODS: A total of 180 patients with 211 submandibular stones treated from January 2012 to December 2020 were included in the current study. Based on the preoperative clinical features of the stones, independent risk factors for ERF were identified by logistic regression analysis. The stones were then randomly divided into training and testing sets. A nomogram was constructed to predict the risk of ERF using the training set and then validated using both sets. The predictive performance of the nomogram was assessed by calibration curves and the concordance index (C-index). RESULTS: Three independent predictors, location (P = 0.040), transverse diameter (P < 0.001) and longitudinal diameter (P < 0.001) measured on the cone beam computed tomography (CBCT) images of the submandibular stones, were identified and included in the predictive nomogram. Calibration curves of the nomogram showed good agreement between the predicted and observed probabilities in both sets. The C-index in the training set was 0.917 (95%CI, 0.875-0.959) and that in the testing set was 0.925 (95%CI, 0.862-0.989). CONCLUSION: A nomogram based on the location, transverse and longitudinal diameters on CBCT images of submandibular stones showed satisfactory efficacy in predicting the risk of ERF preoperatively when treating submandibular stones.
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PURPOSE: Ameloblastoma is a benign odontogenic neoplasm with a high local recurrence rate if the operation is not thorough. However, a useful clinical tool for the quantitative assessment of the prognosis and risk of postoperative recurrence of ameloblastoma has not yet been constructed. This study aims to develop a prognostic nomogram model for ameloblastoma of the jaw to assist surgeons in surgical decision-making. PATIENTS AND METHODS: Patients who underwent initial surgery for ameloblastoma in our department from October 2004 to March 2020 were enrolled and randomly divided into training and validation sets. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify the independent prognostic factors, from which a nomogram for predicting 3-, 5- and 10-year recurrence-free survival (RFS) of ameloblastoma was constructed using the training set and internally validated using the validation set. The model performance was assessed by Harrell's concordance index (C-index) and calibration curves. RESULTS: A total of 302 eligible patients with ameloblastoma were enrolled, 54 of whom were confirmed to relapse during the follow-up period of 6 to 191 months. Four independent predictors, including cortical bone perforation, root(s) resorption, WHO classification, and treatment pattern, were identified and included in the construction of a nomogram for recurrence-free survival (RFS), which showed promising calibration performance and discrimination in the training set (C-index 0.790, 95% confidence interval [CI] 0.735-0.845) and the validation set (C-index 0.734, 95% CI 0.599-0.869). CONCLUSION: A favorable nomogram was developed that accurately predicted the RFS of patients with ameloblastoma based on individual characteristics. Risk stratification using the nomogram could optimize tailored therapy and follow-up.
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Streptococcus pyogenes (group A Streptococcus [GAS]) is an important human pathogen causing a broad spectrum of diseases and associated with significant global morbidity and mortality. Almost all GAS isolates express a surface hyaluronic acid capsule, a virulence determinant that facilitates host colonization and impedes phagocyte killing. However, recent epidemiologic surveillance has reported a sustained increase in both mucosal and invasive infections caused by nonencapsulated GAS, which questions the indispensable role of hyaluronic acid capsule in GAS pathogenesis. In this study, we found that pilus of M4 GAS not only significantly promotes biofilm formation, adherence, and cytotoxicity to human upper respiratory tract epithelial cells and keratinocytes, but also promotes survival in human whole blood and increased virulence in murine models of invasive infection. T4 antigen, the pilus backbone protein of M4 GAS, binds haptoglobin, an abundant human acute-phase protein upregulated upon infection and inflammation, on the bacterial surface. Haptoglobin sequestration reduces the susceptibility of nonencapsulated M4 GAS to antimicrobial peptides released from activated neutrophils and platelets. Our results reveal a previously unappreciated virulence-promoting role of M4 GAS pili, in part mediated by co-opting the biology of haptoglobin to mitigate host antimicrobial defenses.IMPORTANCE Group A Streptococcus (GAS) is a strict human pathogen causing more than 700 million infections globally each year. The majority of the disease-causing GAS are encapsulated, which greatly guarantees survival and dissemination in the host. Emergence of the capsule-negative GAS, such as M4 GAS, in recent epidemiologic surveillance alarms the necessity to elucidate the virulence determinants of these pathogens. Here, we found that M4 pili play an important role in promoting M4 GAS adherence and cytotoxicity to human pharyngeal epithelial cells and keratinocytes. The same molecule also significantly enhanced M4 GAS survival and replication in human whole blood and experimental murine infection. T4 antigen, which composes the backbone of M4 pili, was able to sequester the very abundant serum protein haptoglobin to further confer M4 GAS resistance to antibacterial substances released by neutrophils and platelets.