In order to study the mechanism by which an omental pedicle promotes healing when applied to an injured site, we injected a foreign body into the abdominal cavity to activate the omentum. One week after the injection, we isolated the omentum and measured blood vessel density, blood content, growth and angiogenesis factors (VEGF and others), chemotactic factors (SDF-1 alpha), and progenitor cells (CXCR-4, WT-1). We found that the native omentum, which consisted mostly of adipose tissue, expanded the mass of its non-adipose part (milky spots) 15- to 20-fold. VEGF and other growth factors increased by two- to four-fold, blood vessel density by three-fold, and blood content by two-fold. The activated omentum also showed increases in SDF-1 alpha, CXCR-4, and WT-1 cells (factors and cells positively associated with tissue regeneration). Thus, we propose that an omentum activated by a foreign body (or by injury) greatly expands its milky-spot tissue and becomes rich in growth factors and progenitor cells that facilitate the healing and regeneration of injured tissue.

When rat omentum becomes activated by intraperitoneal injection of inert polydextran particles, these particles are rapidly surrounded by cells that express markers of adult stem cells (SDF-1alpha, CXCR4, WT-1) and of embryonic pluripotent cells (Oct-4, Nanog, SSEA-1). We have cultured such cells, because they may offer a convenient source of adult stem cells, and have found that they retain stem cell markers and produce high levels of vascular endothelial growth factor for up to ten passages. After systemic or local injection of these cultured cells into rats with acute injury of various organs, the cells specifically engraft at the injured sites. Thus, our experiments show that omental stromal cells can be cultured from activated omentum, and that these cells exhibit stem cell properties enabling them to be used for repair and possibly for the regeneration of damaged tissues.

Background: Nonprofessional phagocytes, like epithelial cells, recognize apoptotic cells. Results: Apoptotic cells mimic the effects of intracellular energy depletion and inhibit the growth (cell size) of epithelial cells with which they interact. Conclusion: Apoptotic cells activate AMP-activated protein kinase (AMPK) and inhibit cell growth. Significance: By acting as sentinels of environmental stress, apoptotic targets enable nearby cells to monitor and adapt to local change.

Background: Virtual reality (VR) is an evolving technology that is becoming a common treatment for pain management and psychological phobias. While non-immersive devices (i.e., the Nintendo Wii) have been previously tested with hemodialysis patients, no studies to date have used fully-immersive VR as a tool for intervention delivery. The current pilot trial tests the initial safety, acceptability, and utility of VR during maintenance hemodialysis treatment sessions-particularly, whether VR triggers motion sickness that mimics or negatively impact treatment related symptoms (e.g., nausea). Methods: Hemodialysis patients (n=20) were enrolled in a Phase I single-arm proof-of-concept trial. While undergoing hemodialysis, participants were exposed to our new JovialityTM VR program. This 25-minute program delivers mindfulness training and guided meditation using the Oculus Rift head-mounted display. Participants experienced the program on two separate occasions. Prior and immediately following exposure, participants recorded motion-related symptoms and related discomfort on the Simulator Sickness Questionnaire. Utility measures included end-user's ability to be fully immersed in the virtual space, interact with virtual objects, find hardware user-friendly, and easily navigate the JovialityTM program with the System Usability Score scale. Results: Mean age was 55.3 (+/-13.1) years; 80% male; 60% African American; and mean dialysis vintage was 3.56 (+/-3.75) years. At the first session, there were significant decreases in treatment and/or motion-related symptoms following VR exposure (22.6 vs. 11.2; p=0.03); scores >20 indicate problematic immersion. HD end-users reported high levels of immersion in the VR environment and rated the software easy to operate, with average System Usability Scores of 82.8/100. Conclusions: Hemodialysis patients routinely suffer from fatigue, nausea, lightheadedness, and headaches that often manifest during their dialysis sessions. Our JovialityTM VR program decreased symptom severity without adverse effects. VR programs may be a safe platform to improve the dialysis patient experience.