Prone Position Minimizes the Exacerbation of Effort-dependent Lung Injury: Exploring the Mechanism in Pigs and Evaluating Injury in Rabbits.

Background: Vigorous spontaneous effort can potentially worsen lung injury. This study hypothesized that the prone position would diminish a maldistribution of lung stress and inflation after diaphragmatic contraction and reduce spontaneous effort, resulting in less lung injury.

Methods: A severe acute respiratory distress syndrome model was established by depleting surfactant and injurious mechanical ventilation in 6 male pigs ("mechanism" protocol) and 12 male rabbits ("lung injury" protocol).

Impact of Reverse Triggering Dyssynchrony during Lung-Protective Ventilation on Diaphragm Function: An Experimental Model.

Reverse triggering dyssynchrony (RT) is a patient-ventilator interaction where a respiratory muscle contraction is triggered by a passive mechanical insufflation. Its impact on diaphragm structure and function is unknown. To establish an animal model of RT with lung injury receiving lung-protective ventilation and to assess its impact on the structure and function of the diaphragm.

Embryonic-Derived Macrophages Enhance Bacterial Clearance and Improve Survival in Rat Sepsis.

Peritoneal resident macrophages play a key role in combating sepsis in the peritoneal cavity. We sought to determine if peritoneal transplantation of embryonic "peritoneal-like" macrophages attenuate abdominal fecal sepsis. Directed differentiation of rodent pluripotent stem cells (PSCs) was used in factor-defined media to produce embryonic-derived large "peritoneal-like" macrophages (Ed-LPM) that expressed peritoneal macrophage markers and demonstrated phagocytic capacity.

Human Umbilical Cord Mesenchymal Stromal Cells Attenuate Systemic Sepsis in Part by Enhancing Peritoneal Macrophage Bacterial Killing via Heme Oxygenase-1 Induction in Rats.

Background: Mesenchymal stromal cells have therapeutic potential in sepsis, but the mechanism of action is unclear. We tested the effects, dose-response, and mechanisms of action of cryopreserved, xenogeneic-free human umbilical cord mesenchymal stromal cells in a rat model of fecal peritonitis, and examined the role of heme oxygenase-1 in protection.

Methods: Separate in vivo experiments evaluated mesenchymal stromal cells in fecal sepsis, established dose response (2, 5, and 10 million cells/kg), and the role of heme oxygenase-1 in mediating human umbilical cord-derived mesenchymal stromal/stem cell effects.