Mixed Reality-Based Simulator for Training on Imageless Navigation Skills in Total Hip Replacement Procedures

Imageless navigation systems (INS) in orthopaedics have been used to improve the outcomes of several orthopaedic procedures such as total hip replacement [1, 2]. However, the increased surgical times and the associate learning curve discourage surgeons from using navigation systems in their theatres [2]. This paper presents a Mixed Reality (MR) simulator that helps surgeons acquire the infrared based navigation skills before performing it in reality. A group of 7 hip surgeons tried the application, expressing their satisfaction with all the features and confirmed that the simulator represents a cheaper and faster option to train surgeons in the use of INS than the current learning methods

Activin enhances skin tumourigenesis and malignant progression by inducing a pro-tumourigenic immune cell response

Activin is an important orchestrator of wound repair, but its potential role in skin carcinogenesis has not been addressed. Here we show using different types of genetically modified mice that enhanced levels of activin in the skin promote skin tumour formation and their malignant progression through induction of a pro-tumourigenic microenvironment. This includes accumulation of tumour-promoting Langerhans cells and regulatory T cells in the epidermis. Furthermore, activin inhibits proliferation of tumour-suppressive epidermal γδ T cells, resulting in their progressive loss during tumour promotion. An increase in activin expression was also found in human cutaneous basal and squamous cell carcinomas when compared with control tissue. These findings highlight the parallels between wound healing and cancer, and suggest inhibition of activin action as a promising strategy for the treatment of cancers overexpressing this factor

Dose-Dependent Onset of Regenerative Program in Neutron Irradiated Mouse Skin

Background: Tissue response to irradiation is not easily recapitulated by cell culture studies. The objective of this investigation was to characterize, the transcriptional response and the onset of regenerative processes in mouse skin irradiated with different doses of fast neutrons. Methodology/Principal Findings: To monitor general response to irradiation and individual animal to animal variation, we performed gene and protein expression analysis with both pooled and individual mouse samples. A high-throughput gene expression analysis, by DNA oligonucleotide microarray was done with three months old C57Bl/6 mice irradiated with 0.2 and 1 Gy of mono-energetic 14 MeV neutron compared to sham irradiated controls. The results on 440 irradiation modulated genes, partially validated by quantitative real time RT-PCR, showed a dose-dependent up-regulation of a subclass of keratin and keratin associated proteins, and members of the S100 family of Ca2+-binding proteins. Immunohistochemistry confirmed mRNA expression data enabled mapping of protein expression. Interestingly, proteins up-regulated in thickening epidermis: keratin 6 and S100A8 showed the most significant up-regulation and the least mouse-to-mouse variation following 0.2 Gy irradiation, in a concerted effort toward skin tissue regeneration. Conversely, mice irradiated at 1 Gy showed most evidence of apoptosis (Caspase-3 and TUNEL staining) and most 8-oxo-G accumulation at 24 h post-irradiation. Moreover, no cell proliferation accompanied 1 Gy exposure as shown by Ki67 immunohistochemistry. Conclusions/Significance: The dose-dependent differential gene expression at the tissue level following in vivo exposure to neutron radiation is reminiscent of the onset of re-epithelialization and wound healing and depends on the proportion of cells carrying multiple chromosomal lesions in the entire tissue. Thus, this study presents in vivo evidence of a skin regenerative program exerted independently from DNA repair-associated pathways

Review of Intrinsic Motivation in Simulation-based Game Testing

This paper presents a review of intrinsic motivation in player modeling, with a focus on simulation-based game testing. Modern AI agents can learn to win many games; from a game testing perspective, a remaining research problem is how to model the aspects of human player behavior not explained by purely rational and goal-driven decision making. A major piece of this puzzle is constituted by intrinsic motivations, i.e., psychological needs that drive behavior without extrinsic reinforcement such as game score. We first review the common intrinsic motivations discussed in player psychology research and artificial intelligence, and then proceed to systematically review how the various motivations have been implemented in simulated player agents. Our work reveals that although motivations such as competence and curiosity have been studied in AI, work on utilizing them in simulation-based game testing is sparse, and other motivations such as social relatedness, immersion, and domination appear particularly underexplored

αBSM failed as a carrier of rhBMP-2 to enhance bone consolidation in a sheep model of distraction osteogenesis

One of the problems associated with callus distraction is a long time period needed for consolidation of the newly formed bone. The goal of this study was to determine whether percutaneous injections of rhBMP 2 in BSM would enhance bone consolidation. Methods: A unilateral tibial osteotomy combined with external stabilization was performed in 20 adult sheep. After a latency of four days, distraction was conducted for 20 days. Sheep were divided into three groups: group 1 received rhBMP-2/αBSM injections at day 23 and 30, group 2 buffer/BSM injections at day 23 and 30 and group 3 did not receive any injection. The radiographs and in-vivo torsional stiffness measurements were obtained weekly during the following 50 days. Post-mortem bone densitometry (DXA) and mechanical testing were performed. Results: In-vivo stiffness assessments, DXA values and the maximum torsional moment of the sheep tibia treated with two rhBMP-2 injections were not significantly greater than those of both control groups. Conclusions: Presented application of rhBMP-2 in BSM failed to enhance bone consolidation in distraction osteogenesis