Design and usability evaluation of a mobile-based-self-management application for caregivers of children with severe burns

Paediatric burns are a major public health issue because of long-term physical, psychological and social consequences and the high cost of treatment. The aim of this study was to design and evaluate a mobile-based self-management application for caregivers of children with severe burns. A participatory design technique was employed to develop the Burn application, which included three main phases: the determination of application requirements, the design and evaluation of the low-fidelity prototype, and the design and evaluation of the high-fidelity prototypes. In the first phase, application requirements were determined via validated paper questionnaires using the Delphi technique. In the second step, a low-fidelity prototype was prepared using conceptual models and evaluated through a focus group with specialists. Seven specialists reviewed the application and evaluated how this prototype meets functional requirements and objectives. The third phase was performed in three stages. First, the high-fidelity prototype was designed and developed by the JAVA programming language. Second, a cognitive walk-through was carried out to show how users can interact with the mobile application and how it works. Third, this program was installed on the mobile phones of 28 caregivers of burned children, eight IT experts, and two general surgeries, and the prototype's usability was evaluated. In the present study, most caregivers of children with burns stated that after discharge, they face problems regarding infection control and wound care (4.07) and how to perform physical activity (4.12). User registration, educational materials, caregiver-clinician communication, chat box, and appointment booking, safe login were the most important characteristic of the Burn application. Mean usability evaluation scores were in the range of 7.92 ± 0.238 to 8.10 ± 0.103, which is considered at a “good” level. From the Burn program design experience, it can be concluded that co-design with health care specialists can significantly support and meet the specialists' and patients' needs and ensure the program's usefulness. In addition, application evaluation by users involved and not involved in the application design process can help enhance usability.     

Spectral Shift Originating from Non-linear Ultrasonic Wave Propagation and Its Effect on Imaging Resolution

An amplitude-dependent downshift in the fundamental wave spectrum of a propagating ultrasonic pulse caused by non-linear wave propagation is described. The effects of non-linearity and the associated downshift on spatial resolution are also studied. The amounts of downshift and spatial resolution are extracted from the numerically simulated beam profile based on the KZK equation. Results for a 25-MHz transducer reveal that non-linear effects can lead to 58% additional downshift in the centre frequency of a pulse compared with a linear case with downshift caused only by attenuation. This additional downshift causes about 50% degradation in axial resolution. However, as the beam becomes narrower from the non-linear effects, the overall effect of non-linearity still leads to improved lateral resolution (≤26%). Therefore, as non-linearity increases with wave pressure, it is concluded that the increase in source pressure improves lateral resolution and degrades axial resolution.     

Mycotic Common Iliac Artery Aneurysm Complicating Methicillin-Resistant Staphylococcus aureus Bacteremia: An Unusual Cause of Ureteric Obstruction

A 60-year-old man presented with ureteric obstruction secondary to a mycotic right common iliac artery aneurysm complicating methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. The diagnosis of MRSA was not known at the time of surgery, and in situ replacement of the aneurysm using a rifampicin-bonded prosthesis was performed. The patient made a full recovery, and to date there is no evidence of residual or recurrent infection. To our knowledge, this is the first reported case of mycotic iliac aneurysm infected with MRSA in the literature. We discuss the consequences and the considerable diagnostic and therapeutic problems that arise. Presented at the Fifty-third International Congress of the European Society for Cardiovascular Surgery, Ljubljana, Slovenia, June 2-5, 2004.     

Gene Therapy of Patient-Derived T Lymphocytes to Target and Eradicate Colorectal Hepatic Metastases

PURPOSE: The overall aim of this study was to develop a novel treatment for colorectal cancer based on the use of gene therapy. Genetic modification of T lymphocytes has been used to specifically target and kill tumor cell lines directly. To test the efficacy of this method with clinically relevant materials, this study investigated the potential of T lymphocytes derived from patients with advanced colorectal disease to target autologous primary tumor material. METHODS: T lymphocytes isolated preoperatively were modified genetically with recombinant retroviruses encoding CD3-based chimeric immune receptors and were tested for functional activity against freshly isolated autologous tumor cells harvested from hepatic colorectal metastases. RESULTS: Patient-derived T cells were successfully transduced, and chimeric immune receptor expression was confirmed. Carcinoembryonic antigen expression on freshly isolated colorectal tumor cells was also demonstrated by molecular and immunohistochemical techniques. T cells expressing the anticarcinoembryonic antigen receptor were specifically activated by coculture with disaggregated or intact, diced tumor, whereas control non-carcinoembryonic antigen-targeted T-cell populations failed to activate. CONCLUSIONS: These results indicate that gene-targeted primary T lymphocytes depict specific functional activity against autologous colorectal tumor cells. This evidence indicates that chimeric immune receptor-expressing T cells may be able to circumvent the mechanisms used by tumor cells to avoid immune cell activity in vivo. This study emphasizes the potential of this approach as a therapy for carcinoembryonic antigen-expressing primary colorectal tumor and its metastases.     

Non-linear Wave Propagation and Safety Standards for Diagnostic Ultrasound Devices

Safety standards for clinical diagnostic ultrasonic devices were developed for use in relatively low-frequency systems (1–10 MHz), under the assumption that non-linear effects would be negligible. This article reviews ways in which neglecting non-linear wave propagation affects the measurements and calculations required to comply with safety standards and U.S. Food and Drug Administration guidance that recognizes these standards. An attempt is made to evaluate whether ignoring non-linear effects could result in significant error in the exposure quantities defined in these standards at either low or high frequencies, based on published literature. This article maintains that although non-linear effects have been considered in some parts of safety standards related to hydrophone requirements, the coverage is inadequate, especially for modern equipment with high working frequencies. A new approach is required to assess the magnitude of thermal heating for recently developed high-frequency systems to incorporate non-linear effects. In contrast, the current approach for evaluating the risk of cavitation can be used after appropriate modifications.     

Induction of angiogenesis in tissue-engineered scaffolds designed for bone repair: a combined gene therapy-cell transplantation approach

One of the fundamental principles underlying tissue engineering approaches is that newly formed tissue must maintain sufficient vascularization to support its growth. Efforts to induce vascular growth into tissue-engineered scaffolds have recently been dedicated to developing novel strategies to deliver specific biological factors that direct the recruitment of endothelial cell (EC) progenitors and their differentiation. The challenge, however, lies in orchestration of the cells, appropriate biological factors, and optimal factor doses. This study reports an approach as a step forward to resolving this dilemma by combining an ex vivo gene transfer strategy and EC transplantation. The utility of this approach was evaluated by using 3D poly(lactide-co-glycolide) (PLAGA) sintered microsphere scaffolds for bone tissue engineering applications. Our goal was achieved by isolation and transfection of adipose-derived stromal cells (ADSCs) with adenovirus encoding the cDNA of VEGF. We demonstrated that the combination of VEGF releasing ADSCs and ECs results in marked vascular growth within PLAGA scaffolds. We thereby delineate the potential of ADSCs to promote vascular growth into biomaterials.