Dermal γδ T-Cells Can Be Activated by Mitochondrial Damage-Associated Molecular Patterns.

BACKGROUND: Gamma delta T-cells have been shown to be important to the early immunoinflammatory response to injury, independent of infection. This unique T-cell population acts to regulate cell trafficking and the release of cytokines and growth factors. We propose this sterile inflammatory response is in part associated with damage associated molecular patterns (DAMPs) generated by major injury, such as burn, and mediated via toll-like receptors (TLRs). It is unknown whether DAMPs can activate resident γδ T-cells that reside in skin. METHODS: Gamma delta T-cells were isolated from the skin of male C57BL/6 mice by enzymatic digestion. Mitochondrial DAMPs (MTDs) were generated from mitochondria isolated from mouse livers by sonication and centrifugation. Dermal γδ T-cells were incubated with MTDs (0-500 µg/ml) for 24 hr and cells and supernatants were collected for analysis. RESULTS: MTDs activated dermal γδ T-cells, as evidenced by increased TLR2 and TLR4 expression following in vitro exposure. MTDs also induced the production of inflammatory cytokines (IL-1ß, IL-6), and growth factors (PDGF and VEGF) by γδ T-cells. CONCLUSIONS: These findings herein support the concept that MTDs released after tissue/cellular injury are capable of activating dermal γδ T-cells. We propose that the activation of this unique T-cell population is central in the initiation of sterile inflammation and also contributes to the subsequent healing processes.

Small Bowel Perforations by Metallic Grill Brush Bristles: Clinical Presentations and Opportunity for Prevention.

Increasing reports on the incidental ingestion of metallic bristles from barbeque grill cleaning brushes have been reported. We sought to describe the clinical presentation and grilling habits of patients presenting after ingesting metallic bristles in an attempt to identify risk factors. We performed a chart review of six patients with documented enteric injury from metallic bristles. Subjects were contacted and administered a survey focused on the events surrounding the bristle ingestion. We arranged for in-home visits to inspect the grill and grill brush whenever possible. Of the six subjects identified, three (50%) were male, five (83%) were white, and they ranged in age from 18 to 65 years (mean 42.5). All complained of abdominal pain. All bristles were identified by CT scan. Three patients underwent laparoscopic enterorrhaphy, and two underwent laparotomy. The remaining patients did not require intervention. None had replaced their grill brush in at least two years. Surgeon's awareness of this unusual injury is important to identify and manage this problem. Alternative methods to clean the grill should be sought and grill brushes should be replaced at least every two years.

Mass Casualty Incident Management Preparedness: A Survey of the American College of Surgeons Committee on Trauma.

Mass casualty incidents (MCIs) are events resulting in more injured patients than hospital systems can handle with standard protocols. Several studies have assessed hospital preparedness during MCIs. However, physicians and trauma surgeons need to be familiar with their hospital's MCI Plan. The purpose of this survey was to assess hospitals' and trauma surgeon's preparedness for MCIs. Online surveys were e-mailed to members of the American College of Surgeons committee on Trauma Ad Hoc Committee on Disaster and Mass Casualty Management before the March 2012 meeting. Eighty surveys were analyzed (of 258). About 76 per cent were American College of Surgeons Level I trauma centers, 18 per cent were Level II trauma centers. Fifty-seven per cent of Level I and 21 per cent of Level II trauma centers had experienced an MCI. A total of 98 per cent of respondents thought it was likely their hospital would see a future MCI. Severe weather storm was the most likely event (95%), followed by public transportation incident (86%), then explosion (85%). About 83 per cent of hospitals had mechanisms to request additional physician/surgeons, and 80 per cent reported plans for operative triage. The majority of trauma surgeons felt prepared for an MCI and believed an event was likely to occur in the future. The survey was limited by the highly select group of respondents and future surveys will be necessary.

Diurnal salivary cortisol measurement in the neurosurgical-surgical intensive care unit in critically ill acute trauma patients.

Acute trauma patients represent a specific subgroup of the critically ill population due to sudden and dramatic changes in homeostasis and consequently extreme demands on the activity of the hypothalamic-pituitary-adrenocortical (HPA) axis. Salivary cortisol is an accepted surrogate for serum free cortisol in the assessment of HPA axis function. The purpose of this study was (1) to establish the feasibility of salivary cortisol measurement in acute trauma patients in the neurosurgical-surgical intensive care unit (NSICU), and (2) to determine the diurnal pattern of salivary cortisol in the acute phase after injury. Saliva from 50 acute trauma patients was prospectively collected twice a day at 6AM and 4PM during the first week after injury in the NSICU. Mean PM cortisol concentrations were significantly higher in subjects versus controls (p<0.001). Subjects failed to develop the expected PM versus AM decrease in cortisol concentration seen in controls (p=0.005). Salivary cortisol did not vary significantly with baseline Glasgow Coma Scale (GCS), Injury Severity Score, sex, injury type, ethnicity, or age. When comparing mean AM and PM salivary cortisol by GCS severity category (GCS ⩽8 and GCS >8) the AM salivary cortisol was significantly higher in patients with GCS ⩽8 (p=0.002). The results show a loss of diurnal cortisol variation in acute trauma patient in the NSICU during the first week of hospitalization. Patients with severe brain injury had higher morning cortisol levels than those with mild/moderate brain injury.