Pig islet xenotransplantation.

PURPOSE OF REVIEW: The current article reviews the rationale, sources and preparation of pig islets for xenotransplantation, and presents current progress in solving the problems associated with establishing pig islet transplant as a clinical treatment for type 1 diabetes. SUMMARY: Islet transplantation is an effective treatment option for type 1 diabetes, but the available supply of human pancreases is insufficient to meet the need and demand for obtaining islets. Pig islets provide a readily available source for islet transplantation, with trials in non-human primates demonstrating their potential to reverse diabetes. The risk of zoonosis can be reduced by designated pathogen-free breeding of the donor pigs, but porcine endogenous retroviruses (PERVs) that are integrated into the genome of all pigs are especially difficult to eliminate. However, clinical trials have demonstrated an absence of PERV transmission with a significant reduction in the number of severe hypoglycemic episodes and up to 30% reduction in exogenous insulin doses. A number of methods such as production of various transgenic pigs to better xenotransplantation efficiency and the encapsulation of islets to isolate them from the host immune system are currently being tested to overcome the xenograft immune rejection. Furthermore, ongoing research is also shedding light on factors such as the age and breed of the donor pig to determine the optimal islet quantity and function.

Development of a rocking chair for use by children with spinal cord injuries.

PURPOSE: Activity-based locomotor training improves intrinsic trunk control in children with spinal cord injury (SCI). To reinforce these improvements, there is a need to develop community integration activities to allow a patient to apply the retrained nervous system at home. One activity that has been explored is rocking in a rocking chair. This paper describes the design, fabrication, and evaluation of a rocking chair for children with SCI. MATERIALS AND METHODS: The Quality Function Deployment (QFD) design process was used. Fundamental needs and features for the rocking chair were defined in a focus group with experienced therapists, and needs were then rated for importance. A House of Quality (HOQ) matrix was developed to correlate needs with design features, and a prototype design was generated. Virtual motion studies and finite element analysis (FEA) were utilized to assess the design. The chair was fabricated and physical testing was performed, including tipping and static and dynamic load assessments. RESULTS AND CONCLUSIONS: The needs identified through the QFD process were categorized into (1) safety, (2) therapeutic, (3) practical and aesthetic, and (4) data to track chair use. Features selected to meet these needs include safety stops, padding, straps, a stable base, armrests, adjustable footrest, and sensors to capture rocking data. FEA showed a factor of safety (FOS) > 5. Physical testing confirmed physical integrity, load-bearing capacity, and stability of the prototype glider rocking chair. The prototype provides a safe tool for further investigation of rocking for promotion of trunk muscle activation in children with SCI.

Rocking in a rocking chair promotes carryover of gained trunk control capacity, from clinic to home in a population that is non-ambulatory.Rocking provides opportunity for self-practice in population with severely compromised capacity.Rocking is a movement that may be performed when other types of movement cannot be readily performed, e.g., resistance exercise, movement against gravity.Rocking creates opportunity for repetitive, voluntary, self-directed movement that is inherently pleasurable and reinforcing.

Monitoring muscle activity in pediatric SCI: Insights from sensorized rocking chairs and machine-learning.

Introduction: Activity-based therapy is effective at improving trunk control in children with spinal cord injury. A prototype sensorized rocking chair was developed and confirmed as an activity that activates trunk muscles. This study uses data collected from the chair to predict muscle use during rocking. Methods: The prototype rocking chair included sensors to detect forces, accelerations, as well child and chair movement. Children with spinal cord injury and typically developing children (2-12 years), recruited under an approved IRB protocol, were observed rocking while sensor and electromyography data were collected from arm, leg, and trunk muscles. Features from sensor data were used to predict muscle activation using multiple linear regression, regression learning, and neural network modeling. Correlation analysis examined individual sensor contributions to predictions. Results: Neural network models outperformed regression models. Multiple linear regression predictions significantly correlated (p < 0.05) with targets for four of eleven children with SCI, while decision tree regression predictions correlated for five children. Neural network predictions correlated for all children. Conclusions: Embedded sensors capture useful information about muscle activation, and machine learning techniques can be used to inform therapists. Further work is warranted to refine prediction models and to investigate how well results can be generalized.