Inflammation drives tumor growth in an immunocompetent implantable metastasis model.

Nearly 90% of cancer deaths are due to metastasis. Conventional cancer therapeutics including chemotherapy, surgery, and radiotherapy, are effective in treating primary tumors, but may aggravate disseminated tumor cells (DTCs) into regaining a proliferative state. Models isolating the post dissemination environment are needed to address the potential risks of these therapies, however modeling post dissemination environments is challenging. Often, host organisms become moribund due to primary tumor mass before native metastatic niches can evolve. Implantable tissue engineered niches have been used to attract circulating tumor cells independent of the primary tumor. Here, we serially transplant such tissue engineered niches with recruited DTCs in order to isolate the post dissemination environment. After transplantaion, 69% of scaffolds developed overt post-dissemination cancer growth, however 100% of scaffolds did not grow to a life-threatening critical size within twelve weeks. Adjuvant chemotherapy, while initially effective, did not prevent long-term DTC growth in scaffolds. Subjecting these transplanted niches to surgical resection via biopsy punch enhanced CD31, MMP9, Ly6G, and tumor burden compared to control scaffolds. Biopsy punching was able to rescue tumor incidence from prior chemotherapy. This model of serial transplantation of engineered DTC niches is a highly controllable and flexible method of establishing and systematically investigating the post-dissemination niche.

Commercial and Improvised Pelvic Compression Devices: Applied Force and Implications for Hemorrhage Control.

Uncontrolled hemorrhage secondary to unstable pelvic fractures is a preventable cause of prehospital death in the military and civilian sectors. Because the mortality rate associated with unstable pelvic ring injuries exceeds 50%, the use of external compression devices for associated hemorrhage control is paramount. During mass casualty incidents and in austere settings, the need for multiple external compression devices may arise. In assessing the efficacy of these devices, the magnitude of applied force has been offered as a surrogate measure of pubic symphysis diastasis reduction and subsequent hemostasis. This study offers a sensor-circuit assessment of applied force for a convenience sample of pelvic compression devices. The SAM® (structural aluminum malleable) Pelvic Sling II (SAM Medical) and improvised compression devices, including a SAM Splint tightened by a Combat Application Tourniquet® (C-A-T; North American Rescue) and a SAM® Splint tightened by a cravat, as well as two joined cravats and a standard-issue military belt, were assessed in male and female subjects. As hypothesized, compressive forces applied to the pelvis did not vary significantly based on device operator, subject sex, and subject body fat percentage. The use of the military belt as an improvised method to obtain pelvic stabilization is not advised.