Negative-pressure ventilation may have several advantages compared with positive-pressure ventilation. Negative-pressure ventilation simulates natural lung movements, does not require tracheal intubation and may reduce the incidence of barotrauma and adverse cardiovascular events. A group of engineers, doctors and nurses designed and bench-tested the Exovent, a new, lightweight, torso-only, negative-pressure ventilatory support system. We aimed to test the comfort, nursing acceptability and ventilatory support capabilities of the Exovent in healthy adult volunteers. We measured the effect of continuous negative extra-thoracic pressure on functional reserve capacity and the efficacy of ventilation produced by a combination of negative-pressure ventilation and negative end-expiratory pressure. Six members of the development team volunteered to test the device. The application of continuous negative extra-thoracic pressure did not change tidal volumes from baseline levels; however, functional reserve capacity increased by a mean (SD) of 1.1 (0.05) ml.kg-1 .cmH2 O-1 (p = 0.0002). The combination of negative-pressure ventilation and negative end-expiratory pressure produced effective ventilation, with the resting tidal volume being exceeded by the application of -4 cmH2 O of extra-thoracic negative pressure. All the volunteers found the experience comfortable and none had ventilator dysynchrony. The Exovent allowed good nursing and monitoring access and was comfortable in both the semi-recumbent and prone positions. The Exovent delivered effective continuous negative extra-thoracic pressure and negative-pressure ventilation plus negative end-expiratory pressure to healthy adults. Further trials are needed to investigate the clinical utility of the device.Inactivating mutations in human ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) may result in early-onset osteoporosis (EOOP) in haploinsufficiency and autosomal recessive hypophosphatemic rickets (ARHR2) in homozygous deficiency. ARHR2 patients are frequently treated with phosphate supplementation to ameliorate the rachitic phenotype, but elevating plasma phosphorus concentrations in ARHR2 patients may increase the risk of ectopic calcification without increasing bone mass. To assess the risks and efficacy of conventional ARHR2 therapy, we performed comprehensive evaluations of ARHR2 patients at two academic medical centers and compared their skeletal and renal phenotypes with ENPP1-deficient Enpp1asj/asj mice on an acceleration diet containing high phosphate treated with recombinant murine Enpp1-Fc. ARHR2 patients treated with conventional therapy demonstrated improvements in rickets, but all adults and one adolescent analyzed continued to exhibit low bone mineral density (BMD). In addition, conventional therapy was associated with the development of medullary nephrocalcinosis in half of the treated patients. Similar to Enpp1asj/asj mice on normal chow and to patients with mono- and biallelic ENPP1 mutations, 5-week-old Enpp1asj/asj mice on the high-phosphate diet exhibited lower trabecular bone mass, reduced cortical bone mass, and greater bone fragility. Treating the Enpp1asj/asj mice with recombinant Enpp1-Fc protein between weeks 2 and 5 normalized trabecular bone mass, normalized or improved bone biomechanical properties, and prevented the development of nephrocalcinosis and renal failure. The data suggest that conventional ARHR2 therapy does not address low BMD inherent in ENPP1 deficiency, and that ENPP1 enzyme replacement may be effective for correcting low bone mass in ARHR2 patients without increasing the risk of nephrocalcinosis. © 2021 American Society for Bone and Mineral Research (ASBMR).In anatomical education three-dimensional (3D) visualization technology allows for active and stereoscopic exploration of anatomy and can easily be adopted into medical curricula along with traditional 3D teaching methods. However, most often knowledge is still assessed with two-dimensional (2D) paper-and-pencil tests. To address the growing misalignment between learning and assessment, this viewpoint commentary highlights the development of a virtual 3D assessment scenario and perspectives from students and teachers on the use of this assessment tool a 10-minute session of anatomical knowledge assessment with real-time interaction between assessor and examinee, both wearing a HoloLens and sharing the same stereoscopic 3D augmented reality model. learn more Additionally, recommendations for future directions, including implementation, validation, logistic challenges, and cost-effectiveness, are provided. Continued collaboration between developers, researchers, teachers, and students is critical to advancing these processes.Bone loss induced by mechanical unloading is a common skeletal disease, but the precise mechanism remains unclear. The current study investigated the role of histone methylation, a key epigenetic marker, and its cross-talk with DNA methylation in bone loss induced by mechanical unloading. The expression of G9a, ubiquitin-like with PHD and ring finger domains 1 (UHRF1), and DNA methylation transferase 1 (DNMT1) were increased in hind limb unloading (HLU) rats. This was accompanied by an increased level of histone H3 lysine 9 (H3K9) di-/tri-methylation at lncH19 promoter. Then, alteration of G9a, DNMT1, or UHRF1 expression significantly affected lncH19 level and osteogenic activity in UMR106 cells. Osteogenic gene expression and matrix mineralization were robustly promoted after simultaneous knockdown of G9a, DNMT1, and UHRF1. Furthermore, physical interactions of lncH19 promoter with G9a and DNMT1, as well as direct interactions among DNMT1, G9a, and UHRF1 were detected. Importantly, overexpression of DNMT1, G9a, or UHRF1, respectively, resulted in enrichment of H3K9me2/me3 and 5-methylcytosine at lncH19 promoter. Finally, in vivo rescue experiments indicated that knockdown of DNMT1, G9a, or UHRF1 significantly relieved bone loss in HLU rats. In conclusion, our research demonstrated the critical role of H3K9 methylation and its cross-talk with DNA methylation in regulating lncH19 expression and bone loss in HLU rats. Combined targeting of DNMT1, G9a, and UHRF1 could be a promising strategy for the treatment of bone loss induced by mechanical unloading. © 2021 American Society for Bone and Mineral Research (ASBMR).