Biodistribution of lentiviral transduced adipose-derived stem cells for "ex-vivo" regional gene therapy for bone repair.

Ex-vivo gene therapy has been shown to be an effective method for treating bone defects in pre-clinical models. As gene therapy is explored as a potential treatment option in humans, an assessment of the safety profile becomes an important next step. The purpose of this study was to evaluate the biodistribution of viral particles at the defect site and various internal organs in a rat femoral defect model after implantation of human ASCs transduced with lentivirus (LV) with two-step transcriptional activation (TSTA) of bone morphogenetic protein-2 (LV-TSTA-BMP-2). Animals were sacrificed at 4-, 14-, 56-, and 84-days post implantation. The defects were treated with either a standard dose (SD) of 5 million cells or a high dose (HD) of 15 million cells to simulate a supratherapeutic dose. Treatment groups included (1) SD LV-TSTA-BMP-2 (2) HD LV-TSTA-BMP-2, (3) SD LV-TSTA-GFP (4) HD LV-TSTA-GFP and (5) SD nontransduced cells. The viral load at the defect site and ten organs was assessed at each timepoint. Histology of all organs, ipsilateral tibia, and femur were evaluated at each timepoint. There were nearly undetectable levels of LV-TSTA-BMP-2 transduced cells at the defect site at 84-days and no pathologic changes in any organ at all timepoints. In conclusion, human ASCs transduced with a lentiviral vector were both safe and effective in treating critical size bone defects in a pre-clinical model. These results suggest that regional gene therapy using lentiviral vector to treat bone defects has the potential to be a safe and effective treatment in humans.

Label Distribution Learning for Automatic Cancer Grading of Histopathological Images of Prostate Cancer.

We aimed to develop and evaluate an automatic prediction system for grading histopathological images of prostate cancer. A total of 10,616 whole slide images (WSIs) of prostate tissue were used in this study. The WSIs from one institution (5160 WSIs) were used as the development set, while those from the other institution (5456 WSIs) were used as the unseen test set. Label distribution learning (LDL) was used to address a difference in label characteristics between the development and test sets. A combination of EfficientNet (a deep learning model) and LDL was utilized to develop an automatic prediction system. Quadratic weighted kappa (QWK) and accuracy in the test set were used as the evaluation metrics. The QWK and accuracy were compared between systems with and without LDL to evaluate the usefulness of LDL in system development. The QWK and accuracy were 0.364 and 0.407 in the systems with LDL and 0.240 and 0.247 in those without LDL, respectively. Thus, LDL improved the diagnostic performance of the automatic prediction system for the grading of histopathological images for cancer. By handling the difference in label characteristics using LDL, the diagnostic performance of the automatic prediction system could be improved for prostate cancer grading.

Influence of donor age and comorbidities on transduced human adipose-derived stem cell in vitro osteogenic potential.

Human adipose-derived mesenchymal stem cells (ASCs) transduced with a lentiviral vector system to express bone morphogenetic protein 2 (LV-BMP-2) have been shown to reliably heal bone defects in animal models. However, the influence of donor characteristics such as age, sex, race, and medical co-morbidities on ASC yield, growth and bone regenerative capacity, while critical to the successful clinical translation of stem cell-based therapies, are not well understood. Human ASCs isolated from the infrapatellar fat pads in 122 ASC donors were evaluated for cell growth characteristics; 44 underwent additional analyses to evaluate in vitro osteogenic potential, with and without LV-BMP-2 transduction. We found that while female donors demonstrated significantly higher cell yield and ASC growth rates, age, race, and the presence of co-morbid conditions were not associated with differences in proliferation. Donor demographics or the presence of comorbidities were not associated with differences in in vitro osteogenic potential or stem cell differentiation, except that transduced ASCs from healthy donors produced more BMP-2 at day 2. Overall, donor age, sex, race, and the presence of co-morbid conditions had a limited influence on cell yield, proliferation, self-renewal capacity, and osteogenic potential for non-transduced and transduced (LV-BMP-2) ASCs. These results suggest that ASCs are a promising resource for both autologous and allogeneic cell-based gene therapy applications.

Effects of cell seeding technique and cell density on BMP-2 production in transduced human mesenchymal stem cells.

Small animal models have demonstrated the efficacy of ex vivo regional gene therapy using scaffolds loaded with BMP-2-expressing mesenchymal stem cells (MSCs). Prior to clinical translation, optimization of seeding techniques of the transduced cells will be important to minimize time and resource expenditure, while maximizing cell delivery and BMP-2 production. No prior studies have investigated cell-seeding techniques in the setting of transduced cells for gene therapy applications. Using BMP-2-expressing transduced adipose-derived MSCs and a porous ceramic scaffold, this study compared previously described static and dynamic seeding techniques with respect to cell seeding efficiency, uniformity of cell distribution, and in vitro BMP-2 production. Static and negative pressure seeding techniques demonstrated the highest seeding efficiency, while orbital shaking was associated with the greatest increases in BMP-2 production per cell. Low density cell suspensions were associated with the highest seeding efficiency and uniformity of cell distribution, and the greatest increases in BMP-2 production from 2 to 7 days after seeding. Our results highlight the potential for development of an optimized cell density and seeding technique that could greatly reduce the number of MSCs needed to produce therapeutic BMP-2 levels in clinical situations. Further studies are needed to investigate in vivo effects of cell seeding techniques on bone healing.

Improving Lentiviral Transduction of Human Adipose-Derived Mesenchymal Stem Cells.

Lentiviral transduction of human mesenchymal stem cells (MSCs) induces long-term transgene expression and holds great promise for multiple gene therapy applications. Polybrene is the most commonly used reagent to improve viral gene transfer efficiency in laboratory research; however, it is not approved for human use and has also been shown to impair MSC proliferation and differentiation. Therefore, there is a need for optimized transduction protocols that can also be adapted to clinical settings. LentiBOOST (LB) and protamine sulfate are alternative transduction enhancers (TEs) that can be manufactured to current Good Manufacturing Practice standards, are easily applied to existing protocols, and have been previously studied for the transduction of human CD34+ hematopoietic stem cells. In this study, we investigated these reagents for the enhancement of lentiviral transduction of adipose-derived MSCs. We found that the combination of LB and protamine sulfate could yield comparable or even superior transduction efficiency to polybrene, with no dose-dependent adverse effects on cell viability or stem cell characteristics. This combination of TEs represents a valuable clinically compatible alternative to polybrene with the potential to significantly improve the efficiency of lentiviral transduction of MSCs for gene therapy applications.

Hospital Evacuation Implications After the 2016 Kumamoto Earthquake.

During the 2016 Kumamoto earthquake, 10 hospitals took responsibility for complete evacuation, in what has become regarded as one of the largest evacuations of patients in 1 seismic disaster. We aimed to examine the reasons for evacuation and to assess hospital vulnerability as well as preparedness for the earthquake. A multidisciplinary team conducted semi-structured interviews with the hospitals 6 months after the earthquake. The primary reasons for the decision to evacuate hospitals were categorized into 3: 1) Concern for structural safety (4 facilities), 2) Damage to the facility water system (7 facilities), and 3) Cessation of regional water supply (5 facilities).All hospitals decided on immediate evacuation within 30 hours and could not wait for structural engineers to inspect the affected buildings. Damage to sprinklers or water facilities caused severe water shortages and flood, thus requiring weeks to resume inpatient care. The earthquake revealed the vulnerability of rapid building-inspection systems, aging buildings, and water infrastructure.

Token Economy-Based Hospital Bed Allocation to Mitigate Information Asymmetry: Proof-of-Concept Study Through Simulation Implementation.

BACKGROUND: Hospital bed management is an important resource allocation task in hospital management, but currently, it is a challenging task. However, acquiring an optimal solution is also difficult because intraorganizational information asymmetry exists. Signaling, as defined in the fields of economics, can be used to mitigate this problem. OBJECTIVE: We aimed to develop an assignment process that is based on a token economy as signaling intermediary. METHODS: We implemented a game-like simulation, representing token economy-based bed assignments, in which 3 players act as ward managers of 3 inpatient wards (1 each). As a preliminary evaluation, we recruited 9 nurse managers to play and then participate in a survey about qualitative perceptions for current and proposed methods (7-point Likert scale). We also asked them about preferred rewards for collected tokens. In addition, we quantitatively recorded participant pricing behavior. RESULTS: Participants scored the token economy-method positively in staff satisfaction (3.89 points vs 2.67 points) and patient safety (4.38 points vs 3.50 points) compared to the current method, but they scored the proposed method negatively for managerial rivalry, staff employee development, and benefit for patients. The majority of participants (7 out of 9) listed human resources as the preferred reward for tokens. There were slight associations between workload information and pricing. CONCLUSIONS: Survey results indicate that the proposed method can improve staff satisfaction and patient safety by increasing the decision-making autonomy of staff but may also increase managerial rivalry, as expected from existing criticism for decentralized decision-making. Participant behavior indicated that token-based pricing can act as a signaling intermediary. Given responses related to rewards, a token system that is designed to incorporate human resource allocation is a promising method. Based on aforementioned discussion, we concluded that a token economy-based bed allocation system has the potential to be an optimal method by mitigating information asymmetry.

Regional gene therapy for bone healing using a 3D printed scaffold in a rat femoral defect model.

At the present time there are no consistently satisfactory treatment options for some challenging bone loss scenarios. We have previously reported on the properties of a novel 3D-printed hydroxyapatite-composite material in a pilot study, which demonstrated osteoconductive properties but was not tested in a rigorous, clinically relevant model. We therefore utilized a rat critical-sized femoral defect model with a scaffold designed to match the dimensions of the bone defect. The scaffolds were implanted in the bone defect after being loaded with cultured rat bone marrow cells (rBMC) transduced with a lentiviral vector carrying the cDNA for BMP-2. This experimental group was compared against 3 negative and positive control groups. The experimental group and positive control group loaded with rhBMP-2 demonstrated statistically equivalent radiographic and histologic healing of the defect site (p > 0.9), and significantly superior to all three negative control groups (p < 0.01). However, the healed defects remained biomechanically inferior to the unoperated, contralateral femurs (p < 0.01). When combined with osteoinductive signals, the scaffolds facilitate new bone formation in the defect. However, the scaffold alone was not sufficient to promote adequate healing, suggesting that it is not substantially osteoinductive as currently structured. The combination of gene therapy with 3D-printed scaffolds is quite promising, but additional work is required to optimize scaffold geometry, cell dosage and delivery.

Regional Gene Therapy with Transduced Human Cells: The Influence of "Cell Dose" on Bone Repair.

Regional gene therapy using a lentiviral vector containing the BMP-2 complementary DNA (cDNA) has been shown to heal critical-sized bone defects in rodent models. An appropriate "cellular dose" needs to be defined for eventual translation into human trials. The purpose of this study was to evaluate bone defect healing potential and quality using three different doses of transduced human bone marrow cells (HBMCs). HBMCs were transduced with a lentiviral vector containing either BMP-2 or green fluorescent protein (GFP). All cells were loaded onto compression-resistant matrices and implanted in the bone defect of athymic rats. Treatment groups included femoral defects that were treated with a low-dose (1 × 106 cells), standard-dose (5 × 106 cells), and high-dose (1.5 × 107 cells) HBMCs transduced with lentiviral vector containing BMP-2 cDNA. The three control groups were bone defects treated with HBMCs that were either nontransduced or transduced with vector containing GFP. All animals were sacrificed at 12 weeks. The bone formed in each defect was evaluated with plain radiographs, microcomputed tomography (microCT), histomorphometric analysis, and biomechanical testing. Bone defects treated with higher doses of BMP-2-producing cells were more likely to have healed (6/14 of the low-dose group; 12/14 of the standard-dose group; 14/14 of the high-dose group; χ2(2) = 15.501, p < 0.001). None of the bone defects in the control groups had healed. Bone defects treated with high dose and standard dose of BMP-2-producing cells consistently outperformed those treated with a low dose in terms of bone formation, as assessed by microCT and histomorphometry, and biomechanical parameters. However, statistical significance was only seen between defects treated with high dose and low dose. Larger doses of BMP-2-producing cells were associated with a higher likelihood of forming heterotopic ossification. Femurs treated with a standard- and high-dose BMP-2-producing cells demonstrated similar healing and biomechanical properties. Increased doses of BMP-2 delivered through higher cell doses have the potential to heal large bone defects. Adapting regional gene therapy for use in humans will require a balance between promoting bone repair and limiting heterotopic ossification. Impact statement Critical bone loss may result from complex traumatic bone injury (i.e., open fracture or blast injury), revision total joint arthroplasty, and spine pseudoarthrosis. This is a challenging clinical problem to treat and regional gene therapy is an innovative means of addressing it. This study provides information regarding the quantity of cells or "cell dose" of transduced cells needed to treat a critical-sized bone defect in a rat model. This information may be extrapolated for use in humans in future trials.

Promoting Physical Activity in Japanese Older Adults Using a Social Pervasive Game: Randomized Controlled Trial.

BACKGROUND: Pervasive games aim to create more fun and engaging experiences by mixing elements from the real world into the game world. Because they intermingle with players' lives and naturally promote more casual gameplay, they could be a powerful strategy to stimulate physical activity among older adults. However, to use these games more effectively, it is necessary to understand how design elements of the game affect player behavior. OBJECTIVE: The aim of this study was to evaluate how the presence of a specific design element, namely social interaction, would affect levels of physical activity. METHODS: Participants were recruited offline and randomly assigned to control and intervention groups in a single-blind design. Over 4 weeks, two variations of the same pervasive game were compared: with social interaction (intervention group) and with no social interaction (control group). In both versions, players had to walk to physical locations and collect virtual cards, but the social interaction version allowed people to collaborate to obtain more cards. Changes in the weekly step counts were used to evaluate the effect on each group, and the number of places visited was used as an indicator of play activity. RESULTS: A total of 20 participants were recruited (no social interaction group, n=10; social interaction group, n=10); 18 participants remained active until the end of the study (no social interaction group, n=9; social interaction group, n=9). Step counts during the first week were used as the baseline level of physical activity (no social interaction group: mean 46,697.2, SE 7905.4; social interaction group: mean 45,967.3, SE 8260.7). For the subsequent weeks, changes to individual baseline values (absolute/proportional) for the no social interaction group were as follows: 1583.3 (SE 3108.3)/4.6% (SE 7.2%) (week 2), 591.5 (SE 2414.5)/2.4% (SE 4.7%) (week 3), and -1041.8 (SE 1992.7)/0.6% (SE 4.4%) (week 4). For the social interaction group, changes to individual baseline values were as follows: 11520.0 (SE 3941.5)/28.0% (SE 8.7%) (week 2), 9567.3 (SE 2631.5)/23.0% (SE 5.1%) (week 3), and 7648.7 (SE 3900.9)/13.9% (SE 8.0%) (week 4). The result of the analysis of the group effect was significant (absolute change: η2=0.31, P=.04; proportional change: η2=0.30, P=.03). Correlations between both absolute and proportional change and the play activity were significant (absolute change: r=0.59, 95% CI 0.32 to 0.77; proportional change: r=0.39, 95% CI 0.08 to 0.64). CONCLUSIONS: The presence of social interaction design elements in pervasive games appears to have a positive effect on levels of physical activity. TRIAL REGISTRATION: Japan Medical Association Clinical Trial Registration Number JMA-IIA00314; https://tinyurl.com/y5nh6ylr (Archived by WebCite at http://www.webcitation.org/761a6MVAy).

Limited potential of AAV-mediated gene therapy in transducing human mesenchymal stem cells for bone repair applications.

Adeno-associated viral vectors (AAV) are unique in their ability to transduce a variety of both dividing and nondividing cells, with significantly lower risk of random genomic integration and with no known pathogenicity in humans, but their role in ex vivo regional gene therapy for bone repair has not been definitively established. The goal of this study was to test the ability of AAV vectors carrying the cDNA for BMP-2 to transduce human mesenchymal stem cells (MSCs), produce BMP-2, and induce osteogenesis in vitro as compared with lentiviral gene therapy with a two-step transcriptional amplification system lentiviral vector (LV-TSTA). To this end, we created two AAV vectors (serotypes 2 and 6) expressing the target transgene; eGFP or BMP-2. Transduction of human MSCs isolated from bone marrow (BMSCs) or adipose tissue (ASCs) with AAV2-eGFP and AAV6-eGFP led to low transduction efficiency (BMSCs: 3.57% and 8.82%, respectively, ASCs: 6.17 and 20.2%, respectively) and mean fluorescence intensity as seen with FACS analysis 7 days following transduction, even at MOIs as high as 106. In contrast, strong eGFP expression was detectable in all of the cell types post transduction with LV-TSTA-eGFP. Transduction with BMP-2 producing vectors led to minimal BMP-2 production in AAV-transduced cells 2 and 7 days following transduction. In addition, transduction of ASCs and BMSCs with AAV2-BMP-2 and AAV6-BMP-2 did not enhance their osteogenic potential as seen with an alizarin red assay. In contrast, the LV-TSTA-BMP-2-transduced cells were characterized by an abundant BMP-2 production and induction of the osteogenic phenotype in vitro (p < 0.001 vs. AAV2 and 6). Our results demonstrate that the AAV2 and AAV6 vectors cannot induce a significant transgene expression in human BMSCs and ASCs, even at MOIs as high as 106. The LV-TSTA vector is significantly superior in transducing human MSCs; thus this vector would be preferable when developing an ex vivo regional gene therapy strategy for clinical use in orthopedic surgery applications.

Ex vivo regional gene therapy with human adipose-derived stem cells for bone repair.

BACKGROUND: The treatment of complex bone loss scenarios remains challenging. This study evaluates the efficacy of ex vivo regional gene therapy using transduced human adipose-derived stem cells (ASCs) overexpressing bone morphogenetic protein-2 (BMP-2) to treat critical-sized bone defects. METHODS: Critical-sized femoral defects created surgically in immunocompromised rats were treated with ASCs transduced with a lentivirus encoding BMP-2 (Group 1, n = 14), or green fluorescent protein (Group 2, n = 5), nontransduced ASCs (Group 3, n = 5), or rhBMP-2 (Group 4, n = 14). At 12 weeks, femurs were evaluated for quantity and quality of bone formation with plain radiographs, micro-computed tomography, histology/histomorphometry, and biomechanical strength testing. RESULTS: Thirteen of 14 samples in Group 1 and all 14 samples in Group 4 showed radiographic healing, while no samples in either Groups 2 or 3 healed. Groups 1 and 4 had significantly higher radiographic scores (p < 0.001), bone volume fraction (BV/TV) (p < 0.001), and bone area fraction (BA/TA) than Groups 2 and 3 (p < 0.001). Radiographic scores, BV/TV, and BA/TA were not significantly different between Groups 1 and 4. No difference with regards to mean torque, rotation at failure, torsional stiffness, and energy to failure was seen between Groups 1 and 4. CONCLUSIONS: Human ASCs modified to overexpress BMP-2 resulted in abundant bone formation, with the quality of bone comparable to that of rhBMP-2. This strategy represents a promising approach in the treatment of large bone defects in the clinical setting. CLINICAL RELEVANCE: Large bone defects may require sustained protein production to induce an appropriate osteoinductive response. Ex vivo regional gene therapy using a lentiviral vector has the potential to be part of a comprehensive tissue engineering strategy for treating osseous defects.

Visualizing the Cascade Effect of Redesigning Features in an EMR System.

Electronic Medical Record (EMR) systems are complex systems with interdependent features. Redesigning one feature of the system can create a cascade effect affecting the other features. By calculating the cascade effect, the designers can understand how each individual feature could be affected. This understanding allows them to maximize the positive effects and avoid negative consequences of their redesign activities. To understand the cascade effect, the designers can look at their computations' results; a task that becomes more difficult when the number of features grows. To reduce their task load, we propose a tool for visualizing the cascade effect of redesigning features in an EMR system. Our preliminary evaluation with six graduate students shows that visualizing the cascade effect reduces the task load and slightly improves their performance when analyzing the cascade effect. Ways for improving the tool include (i) showing the computation results within the visualization, and (ii) allowing the designers to compare the cascade effect generated by redesigning different features.

Detecting Severe Incidents from Electronic Medical Records Using Machine Learning Methods.

The goal of this research was to design a solution to detect non-reported incidents, especially severe incidents. To achieve this goal, we proposed a method to process electronic medical records and automatically extract clinical notes describing severe incidents. To evaluate the proposed method, we implemented a system and used the system. The system successfully detected a non-reported incident to the safety management department.

Preliminary Evaluation of Market Mechanism-Based Bed Allocation System.

Effective bed management is important for hospital management. Until now, bed allocation process is generally controlled by administrative staffs in centralized manner but it is not always effective. In the present study, we proposed and evaluated new method for bed allocation applying market mechanism via token. Evaluation was performed with newly-developed game-type simulation. Nurse managers as research participants played it and answered for survey. The result showed that the proposed method can be useful with appropriate operational design.

Prioritizing Features to Redesign in an EMR System.

Redesigning Electronic Medical Record (EMR) systems is needed to improve their usefulness and usability. For user-centered redesign, designers should consider which EMR features are the most important to the users. However, prioritizing the EMR features is complicated because: (i) EMR systems involve multiple users with different, and sometimes conflicting, priorities and (ii) targeting one feature will affect other features of the EMR system. In this work, we propose a method for prioritizing the features to target when redesigning an EMR system. The method takes into consideration the different priorities of the users and the relationships between the different features. We illustrate the method through a case study on redesigning EMR systems in Japanese antenatal care settings. Our results show the importance of considering the different types of EMR users and the relationships between different EMR features. Designers could use the proposed method as a decision-aid tool in EMR redesign projects.

Early Nephrosis Detection Based on Deep Learning with Clinical Time-Series Data.

Nephrosis is disease characterized by abnormal protein loss from impaired kidney. We constructed early prediction model using machine learning from clinical time series data, that can predict onset of nephrosis for more than one month. Long short-term memory capable of recognizing temporal sequential data patterns, was adopted as early prediction model for nephrosis. We verified our proposed prediction model has higher accuracy compared with those of baseline classifiers by 5-fold cross validation.

Analysis for the Annual Text Amount of Electronic Medical Records.

The amount of text of electronic medical records and its changes over time are not clear. In designing an electronic medical records system, prediction of the amount of text is important. We analyzed the number of characters described in the electronic medical records. As a result, it became clear that the annual text quantity of electronic medical records follows the lognormal distribution, and also the amount has been increasing year by year.

Ex vivo gene therapy using human bone marrow cells overexpressing BMP-2: "Next-day" gene therapy versus standard "two-step" approach.

Traditionally, ex vivo gene therapy involves a two-step approach, with culture expansion of cells prior to transduction and implantation. We have tried to simplify this strategy and eliminate the time and cost associated with culture expansion, by introducing "next-day" regional gene therapy using human bone marrow cells. The purpose of this study was to determine whether a lentiviral vector (LV) carrying the cDNA for BMP-2 can transduce freshly isolated human BM cells, leading to abundant BMP production and bone formation in vivo, and evaluate the in vivo osteoinductive potential of "next-day" gene therapy and the standard "two-step" tissue culture expansion approach. To this end, human bone marrow cells (HBMC) from patients undergoing total hip arthroplasty were harvested, transduced with a BMP-2-expressing LV either overnight ("next day" gene therapy; ND) or after culture expansion (cultured "two-step" approach; C) and then implanted into a rat critical-sized femoral defect. The animals were randomly assigned to one of the following groups: I; ND-HBMC transduced with LV-TSTA BMP-2, II; ND-HBMC transduced with LV-TSTA GFP, III; non-transduced ND-HBMC; IV; C-HBMC transduced with LV-TSTA BMP-2, V; C-HBMC transduced with LV-TSTA-GFP, VI; non-transduced C-HBMC. Treatment with either "next-day" or cultured HBMC demonstrated a significant increase in new bone formation compared with all negative control groups as seen in plain radiographs, microCT and histologic/histomorphometric analysis. At 12 weeks post-op, complete defect union on plain X-rays occurred in 7/14 animals in the ND-HBMC/BMP-2 group and 12/14 in the C-HBMC/BMP-2 treated rats. The two-step approach was associated with more consistent results, a higher union rate, and superiority with regards to all of the studied bone healing parameters. In this study we demonstrate proof of concept that BMP-2-transduced human bone marrow cells can be used to enhance bone healing in segmental bone defects, and that regional gene therapy using lentiviral transduction has the osteoinductive potential to heal large bone defects in clinical settings.

Pervasive game design to evaluate social interaction effects on levels of physical activity among older adults.

INTRODUCTION: Promoting active lifestyles among older adults can bring drastic benefits for their quality of life. The innovative mechanics of pervasive games - that mix real and virtual worlds - can further engage and motivate elderly people into that goal. Using social interaction as a study case, we designed and evaluated the feasibility of a pervasive game to investigate how game design elements can affect the levels of physical activity of older adults. METHODS: A mobile, location-based pervasive game was developed, and a study with community dwelling elderly volunteers from Kyoto, Japan was performed to evaluate its feasibility as an experiment system. RESULTS: Participants reported that the theme and visual style of the game was adequate, and that game rules and goals could be easily understood. The game was considered enjoyably challenging and engaging. Further analysis showed that next iterations of the system must pay special attention to the level of complexity of controls, and that new ways to connect players when there are few people playing or when they are too far apart are necessary. CONCLUSIONS: The design allowed to test for variations on pervasive mechanics and was effective to engage elderly people, encouraging further investigation.