Critical care medicine
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Critical care medicine · Feb 2017
Secreted Frizzled-Related Protein 2 and Inflammation-Induced Skeletal Muscle Atrophy.
In sepsis, the disease course of critically ill patients is often complicated by muscle failure leading to ICU-acquired weakness. The myokine transforming growth factor-β1 increases during inflammation and mediates muscle atrophy in vivo. We observed that the transforming growth factor-β1 inhibitor, secreted frizzled-related protein 2, was down-regulated in skeletal muscle of ICU-acquired weakness patients. We hypothesized that secreted frizzled-related protein 2 reduction enhances transforming growth factor-β1-mediated effects and investigated the interrelationship between transforming growth factor-β1 and secreted frizzled-related protein 2 in inflammation-induced atrophy. ⋯ Muscular secreted frizzled-related protein 2 is down-regulated in ICU-acquired weakness patients and mice with inflammation-induced muscle atrophy. Decreased secreted frizzled-related protein 2 possibly establishes a positive feedback loop enhancing transforming growth factor-β1-mediated atrophic effects in inflammation-induced atrophy.
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Critical care medicine · Feb 2017
Collapse of the Microbiome, Emergence of the Pathobiome, and the Immunopathology of Sepsis.
The definition of sepsis has been recently modified to accommodate emerging knowledge in the field, while at the same time being recognized as challenging, if not impossible, to define. Here, we seek to clarify the current understanding of sepsis as one that has been typically framed as a disorder of inflammation to one in which the competing interests of the microbiota, pathobiota, and host immune cells lead to loss of resilience and nonresolving organ dysfunction. Here, we challenge the existence of the idea of noninfectious sepsis given that critically ill humans never exist in a germ-free state. Finally, we propose a new vision of the pathophysiology of sepsis that includes the invariable loss of the host's microbiome with the emergence of a pathobiome consisting of both "healthcare-acquired and healthcare-adapted pathobiota." Under this framework, the critically ill patient is viewed as a host colonized by pathobiota dynamically expressing emergent properties which drive, and are driven by, a pathoadaptive immune response.
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Critical care medicine · Feb 2017
Cryopreserved, Xeno-Free Human Umbilical Cord Mesenchymal Stromal Cells Reduce Lung Injury Severity and Bacterial Burden in Rodent Escherichia coli-Induced Acute Respiratory Distress Syndrome.
Although mesenchymal stem/stromal cells represent a promising therapeutic strategy for acute respiratory distress syndrome, clinical translation faces challenges, including scarcity of bone marrow donors, and reliance on bovine serum during mesenchymal stem/stromal cell proliferation. We wished to compare mesenchymal stem/stromal cells from human umbilical cord, grown in xeno-free conditions, with mesenchymal stem/stromal cells from human bone marrow, in a rat model of Escherichia coli pneumonia. In addition, we wished to determine the potential for umbilical cord-mesenchymal stem/stromal cells to reduce E. coli-induced oxidant injury. ⋯ Our results demonstrate that freshly thawed cryopreserved xeno-free human umbilical cord-mesenchymal stem/stromal cells reduce the severity of rodent E. coli-induced acute respiratory distress syndrome. Umbilical cord-mesenchymal stem/stromal cells, therefore, represent an attractive option for future clinical trials in acute respiratory distress syndrome.