Stuart Bunt

Macrophage recognition and phagocytosis of apoptotic fibroblasts is critically dependent on fibroblast-derived thrombospondin 1 and CD36

The induction of fibroblast apoptosis and their clearance by phagocytes is essential for normal wound healing and prevention of scarring. However, little is known about the clearance of apoptotic fibroblasts and whether apoptotic cells are active participants in the recruitment and activation of phagocytes. In this study, we provide the first evidence that apoptotic fibroblasts actively release increased amounts of thrombospondin (TSP1) to actively recruit macrophages. Expression of TSP1 and its receptor CD36 was increased on the surface of apoptotic fibroblasts. By chemical cross-linking and immunoprecipitation we show that TSP1 and CD36 were directly associated. This was confirmed by confocal microscopy. Blockade of either CD36 or TSP1 on apoptotic fibroblasts inhibited phagocytosis. Blockade of alpha v beta 3 integrins as well as CD36 and TSP1 on macrophages inhibited phagocytosis. In contrast, phosphatidylserine or lectins were not involved. These findings suggest that apoptotic fibroblasts release TSP1 as a signal to recruit macrophages while the up-regulated expression of the CD36/TSP1 complex on their cell surface may form a ligand bridging the fibroblast to a complex consisting of alpha v beta 3/CD36/TSP1 on macrophages. These results establish fundamental mechanisms for the clearance of apoptotic fibroblasts and may provide insights into the processes involved in normal wound repair.

Best teaching practices in anatomy education: A critical review.

In this report we review the range of teaching resources and strategies used in anatomy education with the aim of coming up with suggestions about the best teaching practices in this area. There is much debate about suitable methods of delivering anatomical knowledge. Competent clinicians, particularly surgeons, need a deep understanding of anatomy for safe clinical procedures. However, because students have had very limited exposure to anatomy during clinical training, there is a concern that medical students are ill-prepared in anatomy when entering clerkships and residency programs. Therefore, developing effective modalities for teaching anatomy is essential to safe medical practice. Cadaver-based instruction has survived as the main instructional tool for hundreds of years, however, there are differing views on whether full cadaver dissection is still appropriate for a modern undergraduate training. The limitations on curricular time, trained anatomy faculty and resources for gross anatomy courses in integrated or/and system-based curricula, have led many medical schools to abandon costly and time-consuming dissection-based instruction in favour of alternative methods of instruction including prosection, medical imaging, living anatomy and multimedia resources. To date, no single teaching tool has been found to meet curriculum requirements. The best way to teach modern anatomy is by combining multiple pedagogical resources to complement one another, students appear to learn more effectively when multimodal and system-based approaches are integrated. Our review suggests that certain professions would have more benefit from certain educational methods or strategies than others. Full body dissection would be best reserved for medical students, especially those with surgical career intentions, while teaching based on prosections and plastination is more suitable for dental, pharmacy and allied health science students. There is a need to direct future research towards evaluation of the suitability of the new teaching methodologies in new curricula and student perceptions of integrated and multimodal teaching paradigms, and the ability of these to satisfy learning outcomes.

More accurate neuronavigation data provided by biomechanical modeling instead of rigid registration.

It is possible to improve neuronavigation during image-guided surgery by warping the high-quality preoperative brain images so that they correspond with the current intraoperative configuration of the brain. In this work, the accuracy of registration results obtained using comprehensive biomechanical models is compared to the accuracy of rigid registration, the technology currently available to patients. This comparison allows us to investigate whether biomechanical modeling provides good quality image data for neuronavigation for a larger proportion of patients than rigid registration. Preoperative images for 33 cases of neurosurgery were warped onto their respective intraoperative configurations using both biomechanics-based method and rigid registration. We used a Hausdorff distance-based evaluation process that measures the difference between images to quantify the performance of both methods of registration. A statistical test for difference in proportions was conducted to evaluate the null hypothesis that the proportion of patients for whom improved neuronavigation can be achieved, is the same for rigid and biomechanics-based registration. The null hypothesis was confidently rejected (p-value<10−4). Even the modified hypothesis that less than 25% of patients would benefit from the use of biomechanics-based registration was rejected at a significance level of 5% (p-value = 0.02). The biomechanics-based method proved particularly effective for cases experiencing large craniotomy-induced brain deformations. The outcome of this analysis suggests that our nonlinear biomechanics-based methods are beneficial to a large proportion of patients and can be considered for use in the operating theatre as one possible method of improving neuronavigation and surgical outcomes.It is possible to improve neuronavigation during image-guided surgery by warping the high-quality preoperative brain images so that they correspond with the current intraoperative configuration of the brain. In this paper, the accuracy of registration results obtained using comprehensive biomechanical models is compared with the accuracy of rigid registration, the technology currently available to patients. This comparison allows investigation into whether biomechanical modeling provides good-quality image data for neuronavigation for a larger proportion of patients than rigid registration. Preoperative images for 33 neurosurgery cases were warped onto their respective intraoperative configurations using both the biomechanics-based method and rigid registration. The Hausdorff distance-based evaluation process, which measures the difference between images, was used to quantify the performance of both registration methods. A statistical test for difference in proportions was conducted to evaluate the null hypothesis that the proportion of patients for whom improved neuronavigation can be achieved is the same for rigid and biomechanics-based registration. The null hypothesis was confidently rejected (p < 10(-4)). Even the modified hypothesis that fewer than 25% of patients would benefit from the use of biomechanics-based registration was rejected at a significance level of 5% (p = 0.02). The biomechanics-based method proved particularly effective in cases demonstrating large craniotomy-induced brain deformations. The outcome of this analysis suggests that nonlinear biomechanics-based methods are beneficial to a large proportion of patients and can be considered for use in the operating theater as a possible means of improving neuronavigation and surgical outcomes.

Diagnostic accuracy of teledentistry in the detection of dental caries: a systematic review

OBJECTIVE This study sought to systematically review the literature for research evidence for the diagnostic accuracy of teledentistry in the detection of dental caries. METHODS Two reviewers searched PubMed, EMBASE, and Scopus databases through January 2016 for comparative studies that examined the diagnostic accuracy of teledentistry for detecting caries compared with nontelemedicine alternatives. Retrieved studies were screened for inclusion criteria and were evaluated for methodological quality using the quality assessment of diagnostic accuracy studies (QUADAS-2) checklist. RESULTS Of 287 citations identified, 10 met the preset inclusion criteria. Sensitivity and specificity were the most common measures of diagnostic accuracy used in 10 studies. Despite very limited published evidence on the diagnostic accuracy of teledentistry, the reviewed teledentistry studies showed comparable diagnostic performance compared with nontelemedicine alternatives. The average methodological quality of the selected articles is low, since none of the selected studies satisfied all 4 QUADAS-2 domains. Only 6 articles were scored as having a low risk of bias in 3 of 4 of QUADAS-2 domains. All the selected studies had low concerns regarding applicability. The main shortcoming was that in most of the selected studies, the methodology, in particular patient selection and index tests, was insufficiently described. CONCLUSIONS Teledentistry has an acceptable diagnostic performance in the detection of dental caries. However, due to the heterogeneity of the reviewed studies, the generalization of results may be difficult. Further well-designed research to investigate the effectiveness of the teledentistry approach to caries detection is needed to determine the capability of this technology in epidemiologic oral surveys.

End-user acceptance of a cloud-based teledentistry system and Android phone app for remote screening for oral diseases.

Objective This study aimed to evaluate users’ acceptance of a teledentistry model utilizing a smartphone camera used for dental caries screening and to identify a number of areas for improvement of the system. Methods A store-and-forward telemedicine platform “Remote-I” was developed to assist in the screening of oral diseases using an image acquisition Android app operated by 17 teledental assistants. A total of 485 images (five images per case) were directly transmitted from the Android app to the server. A panel of five dental practitioners (graders) assessed the images and reported their diagnosis. A user acceptance survey was sent to the graders and smartphone users following completion of the screening program. Results Of the 22 surveys sent out, 20 (91%) were completed. Generally, users showed optimism towards the use of the teledentistry system, and strongly positively assessed items on content and service quality. The majority of graders took less than 15 min to read the images while phone users took 5–10 min to complete the dental photography using the Android app. This study identified a number of factors that are essential for improving the current system, such as optimization of smartphone camera features, the format of the server, and the orientation of images and using oral retractors during photography. Conclusions Users appear to be generally satisfied with the proposed teledentistry model. However, they have specific concerns to address, many of which could be resolved through more effective training, coordination between sites and upgrading the current system.

A systematic review of the research evidence for the benefits of teledentistry.

Objective This review is designed to inform future decisions about the benefits of integrating teledentistry into routine health services, by presenting an overview of the evidence for the effectiveness and economic impact of teledentistry. Methods Two reviewers searched PubMed, EMBASE and CINAHL databases through November 2016 to identify published peer-reviewed studies in English. Teledentistry studies were included if they were; (a) controlled (randomised or non-randomised) assessment studies; and (b) compared outcomes of a teledentistry intervention in terms of clinical or economic evaluation with the outcomes of traditional clinical alternatives. The quality of the studies was evaluated using a quality appraisal tool that considered study performance and design. Results This review identified 385 publications, of which 217 full-text articles were retrieved for further inspection. Of these, only 11 articles met the inclusion criteria. Nine of the included articles showed some clinical outcomes; the other two were primarily economic analyses. The balance of these studies assesed the efficacy of teledentistry interventions rather than their effectiveness. Four studies (36%) achieved higher quality scores and have greater potential to influence health-care decision-making. To date, the most convincing published evidence regarding the efficacy of teledentistry was provided by studies on paediatric dentistry, orthodontics and oral medicine. The economic analysis referred only to cost-minimisation, suggesting that the use of teleconsultation in dentistry can be cost-saving when compared to a conventional consultation. However, high-quality economic studies on teledentistry are rare. Conclusion There is emerging evidence supporting the efficacy of teledentistry. However, there is not yet enough conclusive evidence, particularly for its effectiveness, cost-effectiveness and long-term use, to make evidence-based policy decisions on teledentistry.

Mechanical Properties of Brain–Skull Interface in Compression

This study investigated mechanical properties of brain–skull interface, important for surgery simulation and injury biomechanics. Direct examination of brain–skull interface is difficult due to its delicate nature and complex geometry that follows the skull and brain surface. Hence, we conducted uniaxial compression tests on samples containing skull, meninges and brain. We combined sophisticated measurement data with non-linear finite element analysis to obtain the properties of brain–skull interface. Skull was considered a rigid object as forces obtained were very small to induce any measurable deformation on it. Surface contact model between brain and skull was used to simulate the brain–skull interface. Good correlation between sample deformation in experiment and simulation was used to confirm the brain–skull interface property.

Cost savings from a teledentistry model for school dental screening: an Australian health system perspective

Objective The aim of the present study was to compare the costs of teledentistry and traditional dental screening approaches in Australian school children. Methods A cost-minimisation analysis was performed from the perspective of the oral health system, comparing the cost of dental screening in school children using a traditional visual examination approach with the cost of mid-level dental practitioners (MLDPs), such as dental therapists, screening the same cohort of children remotely using teledentistry. A model was developed to simulate the costs (over a 12-month period) of the two models of dental screening for all school children (2.7million children) aged 5-14 years across all Australian states and territories. The fixed costs and the variable costs, including staff salary, travel and accommodation costs, and cost of supply were calculated. All costs are given in Australian dollars. Results The total estimated cost of the teledentistry model was

On the appropriateness of modelling brain parenchyma as a biphasic continuum.

50million. The fixed cost of teledentistry was

Biomechanical modeling provides more accurate data for neuronavigation than rigid registration

1million and that of staff salaries (tele-assistants, charters and their supervisors, as well as information technology support was estimated to be