Congenital heart diseases are the most common birth defects around the world. Emerging evidence suggests that mitochondrial homeostasis is required for normal heart development. In mitochondria, a series of molecular chaperones including heat shock protein 60 (HSP60) are engaged in assisting the import and folding of mitochondrial proteins. However, it remains largely obscure whether and how these mitochondrial chaperones regulate cardiac development. Here, we generated a cardiac-specific Hspd1 deletion mouse model by αMHC-Cre and investigated the role of HSP60 in cardiac development. We observed that deletion of HSP60 in embryonic cardiomyocytes resulted in abnormal heart development and embryonic lethality, characterized by reduced cardiac cell proliferation and thinner ventricular walls, highlighting an essential role of cardiac HSP60 in embryonic heart development and survival. Our results also demonstrated that HSP60 deficiency caused significant downregulation of mitochondrial ETC subunits and induced mitochondrial stress. Analysis of gene expression revealed that P21 that negatively regulates cell proliferation is significantly upregulated in HSP60 knockout hearts. Moreover, HSP60 deficiency induced activation of eIF2α-ATF4 pathway, further indicating the underlying mitochondrial stress in cardiomyocytes after HSP60 deletion. Taken together, our study demonstrated that regular function of mitochondrial chaperones is pivotal for maintaining normal mitochondrial homeostasis and embryonic heart development.

ObjectiveThis retrospective analysis aimed to evaluate the prevalence of periodontitis in patients undergoing hematopoietic stem cell transplantation, and investigate the effects of various periodontal statuses and risk factors on oral infection incidence.Study DesignMedical records of patients pre– and post–hematopoietic stem cell transplantation from June 2019 to October 2021were reviewed. The study examined the effort of different periodontal statuses on oral complications and infections in patients during transplantation.ResultsOf 549 transplant patients studied, 363 had periodontitis. patients with or without periodontitis showed significant differences in mean age, male proportion, and mucositis incidence during transplantation (P < 0.05). Bacteremia rates were slightly higher in patients with periodontitis, but not significant. Male proportion, age, and hospitalization duration significantly increased with advancing periodontitis stages. Only two patients experienced periodontal complications, that were effectively managed and did not interfere in the grafting process.ConclusionPeriodontitis is prevalent in patients with hematopoietic diseases. Despite its association with oral mucositis, the occurrence of periodontal infection remains low and controllable.

ObjectiveThis study aimed to investigate the incidence, treatment status, and impact position of impacted third molars (ITM) and their effects on patients undergoing hematopoietic stem cell transplantation (HSCT).MethodsA retrospective analysis was conducted on the medical records of 454 patients who underwent HSCT, out of which 188 patients had ITM. The presence of ITM and its association with transplant-related infections and complications were recorded and analyzed.ResultsPatients with ITM were significantly younger. The number of mandibular ITM was notably higher than maxillary ones, and the risk of pericoronitis in mandibular ITM was significantly higher than in maxillary ones. Out of 311 ITM in 188 patients, 25 were extracted before transplantation. The proportion of extraction and treatment for ITM with pericoronitis or caries was significantly higher than that for ITM without such problems. Moreover, patients with a history of pre-transplant pericoronitis had a significantly higher probability of developing tooth-related complications during transplantation, caused by pericoronitis in ITM compared to patients without a history of pericoronitis.ConclusionPre-transplant examination and treatment of ITM are essential, especially in cases with a history of pericoronitis. Oral intervention can significantly reduce the occurrence of tooth-related complications related to ITM during transplantation.

Currently, resin composites are the most popular materials for dental restoration in clinical practice. Although the properties of such materials have been improved significantly, together with better clinical techniques used for their placement, early restoration failure still occurs too frequently. As clinical studies take years to complete, and new resin composites are being produced at ever increasing pace, laboratory assessment using accelerated but representative tests is necessary. The main types of failure in resin-composite restoration are tooth/restoration fracture and secondary caries, which are caused by a combination of mechanical and biochemical challenges. In this study, a biofilm model (S. mutans) and a chemical model (lactic-acid buffer) for producing artificial caries in bovine dentin are developed and calibrated against in situ data. Using a power law relationship between the demineralization depth and challenge duration, scale factors that convert the in vitro durations to the equivalent clinical durations are determined for different pH values for each model. The scale factors will allow the synchronization of biochemical and mechanical challenges in terms of their rates of action to potentially test resin-composite restoration in an accelerated but clinically representative manner. Statement of significance Although the properties of resin composites for dental restoration have been improved significantly, early restoration failure still occurs too frequently. As clinical studies take years to complete, accelerated laboratory testing is necessary. Resin-composite restoration fail mainly through fracture and secondary caries, caused by a combination of mechanical and biochemical challenges. In this study, a biofilm and a chemical model for producing artificial caries in bovine dentin are calibrated against in situ data. Using a power law relationship between demineralization depth and challenge duration, scale factors are determined for different pH for each model. The scale factors will allow the synchronization of biochemical and mechanical challenges in testing resin-composite restoration in an accelerated but clinically representative manner. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.