Megakaryocytes respond during sepsis and display innate immune cell behaviors.

Megakaryocytes (MKs) are precursors to platelets, the second most abundant cells in the peripheral circulation. However, while platelets are known to participate in immune responses and play significant functions during infections, the role of MKs within the immune system remains largely unexplored. Histological studies of sepsis patients identified increased nucleated CD61+ cells (MKs) in the lungs, and CD61+ staining (likely platelets within microthrombi) in the kidneys, which correlated with the development of organ dysfunction. Detailed imaging cytometry of peripheral blood from patients with sepsis found significantly higher MK counts, which we predict would likely be misclassified by automated hematology analyzers as leukocytes. Utilizing in vitro techniques, we show that both stem cell derived MKs (SC MKs) and cells from the human megakaryoblastic leukemia cell line, Meg-01, undergo chemotaxis, interact with bacteria, and are capable of releasing chromatin webs in response to various pathogenic stimuli. Together, our observations suggest that MK cells display some basic innate immune cell behaviors and may actively respond and play functional roles in the pathophysiology of sepsis.

Associations between clinical characteristics and the development of multiple organ failure after severe burns in adult patients.

To determine the association between potential risk factors and multiple organ failure (MOF) in severe burn adult patients, we performed a secondary analysis of data from the "Inflammation and the Host Response to Injury" database, which included patients from six burn centers in the United States between 2003 and 2009. Three hundred twenty-two adult patients (aged ≥16 years) with severe burns (≥20.0% total body surface area [TBSA]) were included. MOF was defined according to the Denver score. Potential risk factors were analyzed for their association with MOF. Models were built using multivariable logistic regression analysis. Eighty-eight patients (27.3%) developed MOF during the study period. We found that TBSA, age, and inhalation injury were significant risk factors for MOF. This predictive model showed good performance, with the total area under the receiver operating characteristic curve being 0.823. Moreover, among patients who developed MOF, inhalation injury was significantly associated with the development of MOF in the acute phase (within three days of injury) (adjusted odds ratio 3.1; 95% confidence interval 1.1-8.3). TBSA, age, lactate, and Denver score within 24h were associated with the late phase development of MOF. Thus, we have identified key risk factors for the onset of MOF after severe burn injury. Our findings contribute to the understanding of individualized treatment and will potentially allow for efficient allocation of resources and a lower threshold for admission to an intensive care unit, which can prevent the development of MOF and eventually reduce mortality.

Platelet transfusion increases risk for acute respiratory distress syndrome in non-massively transfused blunt trauma patients.

PURPOSE: While damage control resuscitation is known to confer a survival advantage in severely injured patients, high-ratio blood component therapy should be initiated only in carefully selected trauma patients, due to the morbidity associated with blood product use. With this project, we aim to identify the effect of platelet transfusion in non-massively transfused bluntly injured patients. METHODS: The Glue Grant database was retrospectively queried and severely injured blunt trauma patients who underwent non-massive transfusion were identified. Patients were divided into quartiles depending on platelet volume they were transfused in the first 48 h. Outcomes of interest included mortality; ventilator, Intensive Care Unit (ICU) and hospital length of stay (LOS); infectious and non-infectious complications. Multivariable regression models were fitted for these outcomes, controlling for age, pre-existing comorbidities, injury severity, acute physiologic derangement, neurologic injury burden, and other fluid and blood product resuscitation. RESULTS: There was no difference in mortality, LOS, or the incidence of multi-organ failure and infectious complications. However, patients receiving ≥ 250 mL of platelets were more likely to develop acute respiratory distress syndrome (ARDS) compared to those who received < 250 mL [odds ratio 1.91 (95% CI 1.10-3.33, p = 0.022)]. CONCLUSIONS: Pre-emptive platelet transfusion should be avoided in non-massively transfused blunt injury victims in the absence of true or functional thrombocytopenia, as it increases risk for ARDS with no survival benefit.

Development of clinical process measures for pediatric burn care: Understanding variation in practice patterns.

BACKGROUND: There has been little systematic examination of variation in pediatric burn care clinical practices and its effect on outcomes. As a first step, current clinical care processes need to be operationally defined. The highly specialized burn care units of the Shriners Hospitals for Children system present an opportunity to describe the processes of care. The aim of this study was to develop a set of process-based measures for pediatric burn care and examine adherence to them by providers in a cohort of pediatric burn patients. METHODS: We conducted a systematic literature review to compile a set of process-based indicators. These measures were refined by an expert panel of burn care providers, yielding 36 process-based indicators in four clinical areas: initial evaluation and resuscitation, acute excisional surgery and critical care, psychosocial and pain control, and reconstruction and aftercare. We assessed variability in adherence to the indicators in a cohort of 1,076 children with burns at four regional pediatric burn programs in the Shriners Hospital system. The percentages of the cohort at each of the four sites were as follows: Boston, 20.8%; Cincinnati, 21.1%; Galveston, 36.0%; and Sacramento, 22.1%. The cohort included children who received care between 2006 and 2010. RESULTS: Adherence to the process indicators varied both across sites and by clinical area. Adherence was lowest for the clinical areas of acute excisional surgery and critical care, with a range of 35% to 48% across sites, followed by initial evaluation and resuscitation (range, 34%-60%). In contrast, the clinical areas of psychosocial and pain control and reconstruction and aftercare had relatively high adherence across sites, with ranges of 62% to 93% and 71% to 87%, respectively. Of the 36 process indicators, 89% differed significantly in adherence between clinical sites (p < 0.05). Acute excisional surgery and critical care exhibited the most variability. CONCLUSION: The development of this set of process-based measures represents an important step in the assessment of clinical practice in pediatric burn care. Substantial variation was observed in practices of pediatric burn care. However, further research is needed to link these process-based measures to clinical outcomes. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

Strategic Targeting of Multiple BMP Receptors Prevents Trauma-Induced Heterotopic Ossification.

Trauma-induced heterotopic ossification (tHO) is a condition of pathologic wound healing, defined by the progressive formation of ectopic bone in soft tissue following severe burns or trauma. Because previous studies have shown that genetic variants of HO, such as fibrodysplasia ossificans progressiva (FOP), are caused by hyperactivating mutations of the type I bone morphogenetic protein receptor (T1-BMPR) ACVR1/ALK2, studies evaluating therapies for HO have been directed primarily toward drugs for this specific receptor. However, patients with tHO do not carry known T1-BMPR mutations. Here we show that, although BMP signaling is required for tHO, no single T1-BMPR (ACVR1/ALK2, BMPR1a/ALK3, or BMPR1b/ALK6) alone is necessary for this disease, suggesting that these receptors have functional redundancy in the setting of tHO. By utilizing two different classes of BMP signaling inhibitors, we developed a translational approach to treatment, integrating treatment choice with existing diagnostic options. Our treatment paradigm balances either immediate therapy with reduced risk for adverse effects (Alk3-Fc) or delayed therapy with improved patient selection but greater risk for adverse effects (LDN-212854).

An ALPHA7 Nicotinic Acetylcholine Receptor Agonist (GTS-21) Promotes C2C12 Myonuclear Accretion in Association with Release of Interleukin-6 (IL-6) and Improves Survival in Burned Mice.

The role of interleukin-6 (IL-6) in physiological processes and disease is poorly understood. The hypothesis tested in this study was that selective alpha7 acetylcholine receptor (α7AChR) agonist, GTS-21, releases IL-6 in association with myonuclear accretion and enhances insulin signaling in muscle cells, and improves survival of burn injured (BI) mice. The in vitro effects of GTS-21 were determined in C2C12 myoblasts and 7-day differentiated myotubes (myotubes). The in vivo effects of GTS-21 were tested in BI wild-type (WT) and IL-6 knockout (IL6KO) mice. GTS-21 dose-dependently (0 µM, 100 µM, and 200 µM) significantly increased IL-6 levels in myoblasts and myotubes at 6 and 9 h. GTS-21-induced IL-6 release in myotubes was attenuated by methyllycaconitine (α7AChR antagonist), and by Stat-3 or Stat-5 inhibitors. GTS-21 increased MyoD and Pax7 protein expression, myonuclear accretion, and insulin-induced phosphorylation of Akt, GSK-3ß, and Glut4 in myotubes. The glucose levels of burned IL6KO mice receiving GTS-21 decreased significantly compared with sham-burn IL6KO mice. Superimposition of BI on IL6KO mice caused 100% mortality; GTS-21 reduced mortality to 75% in the IL6KO mice. The 75% mortality in burned WT mice was reduced to 0% with GTS-21. The in vitro findings suggest that GTS-21-induced IL-6 release from muscle is mediated via α7AChRs upstream of Stat-3 and -5 pathways and is associated with myonuclear accretion, possibly via MyoD and Pax7 expression. GTS-21 in vivo improves survival in burned WT mice and IL6KO mice, suggesting a potential therapeutic application of α7AChR agonists in the treatment of BI.

iNOS as a Driver of Inflammation and Apoptosis in Mouse Skeletal Muscle after Burn Injury: Possible Involvement of Sirt1 S-Nitrosylation-Mediated Acetylation of p65 NF-κB and p53.

Inflammation and apoptosis develop in skeletal muscle after major trauma, including burn injury, and play a pivotal role in insulin resistance and muscle wasting. We and others have shown that inducible nitric oxide synthase (iNOS), a major mediator of inflammation, plays an important role in stress (e.g., burn)-induced insulin resistance. However, it remains to be determined how iNOS induces insulin resistance. Moreover, the interrelation between inflammatory response and apoptosis is poorly understood, although they often develop simultaneously. Nuclear factor (NF)-κB and p53 are key regulators of inflammation and apoptosis, respectively. Sirt1 inhibits p65 NF-κB and p53 by deacetylating these transcription factors. Recently, we have shown that iNOS induces S-nitrosylation of Sirt1, which inactivates Sirt1 and thereby increases acetylation and activity of p65 NF-κB and p53 in various cell types, including skeletal muscle cells. Here, we show that iNOS enhances burn-induced inflammatory response and apoptotic change in mouse skeletal muscle along with S-nitrosylation of Sirt1. Burn injury induced robust expression of iNOS in skeletal muscle and gene disruption of iNOS significantly inhibited burn-induced increases in inflammatory gene expression and apoptotic change. In parallel, burn increased Sirt1 S-nitrosylation and acetylation and DNA-binding capacity of p65 NF-κB and p53, all of which were reversed or ameliorated by iNOS deficiency. These results indicate that iNOS functions not only as a downstream effector but also as an upstream enhancer of burn-induced inflammatory response, at least in part, by Sirt1 S-nitrosylation-dependent activation (acetylation) of p65 NF-κB. Our data suggest that Sirt1 S-nitrosylation may play a role in iNOS-mediated enhanced inflammatory response and apoptotic change, which, in turn, contribute to muscle wasting and supposedly to insulin resistance after burn injury.

Primary Pancreatic Secretinoma: Further Evidence Supporting Secretin as a Diarrheogenic Hormone.

OBJECTIVES: To document the existence of primary pancreatic secretinoma in patients with watery diarrhea syndrome (WDS) and achlorhydria and establish secretin as a diarrheogenic hormone. BACKGROUND: Vasoactive intestinal peptide (VIP) has been widely accepted as the main mediator of WDS. However, in 1968, Zollinger et al reported 2 female patients with pancreatic neuroendocrine tumors, WDS, and achlorhydria. During surgery on the first, a 24-year-old patient, they noticed distended duodenum filled with fluid and a dilated gallbladder containing dilute bile with high bicarbonate concentration. After excision of the tumor, WDS ceased and gastric acid secretion returned. The second, a 47-year-old, patient's metastatic tumor extract given intravenously in dogs, produced significantly increased pancreatic and biliary fluid rich in bicarbonate. They suggested a secretin-like hormone of islet cell origin explains WDS and achlorhydria. These observations, however, predated radioimmunoassay, immunohistochemical staining, and other molecular studies. METHODS: The first patient's tumor tissue was investigated for secretin and VIP. Using both immunohistochemistry and laser microdissection and pressure catapulting technique for RNA isolation and subsequent reverse transcription polymerase chain reaction, the expression levels of secretin, and VIP were measured. RESULTS: Immunoreactive secretin and its mRNA were predominantly found in the tumor tissue whereas VIP and its mRNA were scarce. CONCLUSIONS: The findings strongly support that the WDS and achlorhydria in this patient may have been caused by secretin as originally proposed in 1968 and that secretin may act as a diarrheogenic hormone.

Hold the Pendulum: Rates of Acute Kidney Injury are Increased in Patients Who Receive Resuscitation Volumes Less than Predicted by the Parkland Equation.

OBJECTIVE: To determine whether restrictive fluid resuscitation results in increased rates of acute kidney injury (AKI) or infectious complications. BACKGROUND: Studies demonstrate that patients often receive volumes in excess of those predicted by the Parkland equation, with potentially detrimental sequelae. However, the consequences of under-resuscitation are not well-studied. METHODS: Data were collected from a multicenter prospective cohort study. Adults with greater than 20% total burned surface area injury were divided into 3 groups on the basis of the pattern of resuscitation in the first 24 hours: volumes less than (restrictive), equal to, or greater than (excessive) standard resuscitation (4 to 6 cc/kg/% total burned surface area). Multivariable regression analysis was employed to determine the effect of fluid group on AKI, burn wound infections (BWIs), and pneumonia. RESULTS: Among 330 patients, 33% received restrictive volumes, 39% received standard resuscitation volumes, and 28% received excessive volumes. The standard and excessive groups had higher mean baseline APACHE scores (24.2 vs 16, P < 0.05 and 22.3 vs 16, P < 0.05) than the restrictive group, but were similar in other characteristics. After adjustment for confounders, restrictive resuscitation was associated with greater probability of AKI [odds ratio (OR) 3.25, 95% confidence interval (95% CI) 1.18-8.94]. No difference in the probability of BWI or pneumonia among groups was found (BWI: restrictive vs standard OR 0.74, 95% CI 0.39-1.40, excessive vs standard OR 1.40, 95% CI 0.75-2.60, pneumonia: restrictive vs standard, OR 0.52, 95% CI 0.26-1.05; excessive vs standard, OR 1.12, 95% CI 0.58-2.14). CONCLUSIONS: Restrictive resuscitation is associated with increased AKI, without changes in infectious complications.

Molecular Imaging of Smoke-Induced Changes in Nuclear Factor-Kappa B Expression in Murine Tissues Including the Lung.

Many inflammatory responses are mediated by activation of the transcription factor, nuclear factor-kappa B (NF-κB), and a wide variety of human diseases involve abnormal regulation of its expression. In this investigation, we evaluated the effect of smoke inhalation injury on NF-κB expression in lung using two strains of NF-κB reporter mice. Groups of reporter mice with viral thymidine kinase (TK) or "fire fly" luciferase (Luc) genes under control by the NF-κB promoter (TK/NF-κB mice and Luc/NF-κB mice) were subjected to nonlethal smoke inhalation injury. Sham-treated animals served as controls. Twenty-four hours (each animal was injected intravenously with either 9-(4-18F-fluoro-3-[hydroxymethyl]butyl)guanine (FHBG) (~ 1.0 mCi) or luciferin (1.0 mg). One hour later, the TK/NF-κB mice were studied by micro-positron emission tomography (µ-PET) imaging using a Concord P4 µ-PET camera, and the Luc/NF-κB mice were studied by bioluminescence imaging with a charge-coupled device camera. The µ-PET data demonstrated that smoke injury produced massive increases in NF-κB expression (FHBG-standardized uptake value: 3.1 vs 0.0) 24 hours after smoke inhalation, which was reduced 48 hours after smoke inhalation, but still significantly different than the control. Qualitative analysis of the bioluminescence data revealed a remarkably similar effect of burn NF-κB luciferase expression in vivo. Biodistribution studies of FHBG uptake and luciferase activity in lung tissue demonstrated a similar increase 24 hours after injury, which was reduced 48 hours later, but still significantly higher than the sham. The present data with these models providing longitudinal imaging data on the same mouse may prove useful in the examination of the factors producing lung injury by smoke inhalation, as well as the treatment(s) for the damage produced with and without burn injury.

Reversal of Growth Arrest With the Combined Administration of Oxandrolone and Propranolol in Severely Burned Children.

BACKGROUND: The hypercatabolic response in severely burned pediatric patients is associated with increased production of catecholamines and corticosteroids, decreased formation of testosterone, and reduced strength alongside growth arrest for up to 2 years after injury. We have previously shown that, in the pediatric burned population, the administration of the testosterone analog oxandrolone improves lean body mass accretion and bone mineral content and that the administration of the ß1-, ß2-adrenoceptor antagonist propranolol decreases cardiac work and resting energy expenditure while increasing peripheral lean mass. Here, we determined whether the combined administration of oxandrolone and propranolol has added benefit. METHODS: In this prospective, randomized study of 612 burned children [52% ±â€Š1% of total body surface area burned, ages 0.5-14 years (boys); ages 0.5-12 years (girls)], we compared controls to the individual administration of these drugs, and the combined administration of oxandrolone and propranolol at the same doses, for 1 year after burn. Data were recorded at discharge, 6 months, and 1 and 2 years after injury. RESULTS: Combined use of oxandrolone and propranolol shortened the period of growth arrest by 84 days (P = 0.0125 vs control) and increased growth rate by 1.7 cm/yr (P = 0.0024 vs control). CONCLUSIONS: Combined administration of oxandrolone and propranolol attenuates burn-induced growth arrest in pediatric burn patients. The present study is registered at clinicaltrials.gov: NCT00675714 and NCT00239668.

Inhibition of Hif1α prevents both trauma-induced and genetic heterotopic ossification.

Pathologic extraskeletal bone formation, or heterotopic ossification (HO), occurs following mechanical trauma, burns, orthopedic operations, and in patients with hyperactivating mutations of the type I bone morphogenetic protein receptor ACVR1 (Activin type 1 receptor). Extraskeletal bone forms through an endochondral process with a cartilage intermediary prompting the hypothesis that hypoxic signaling present during cartilage formation drives HO development and that HO precursor cells derive from a mesenchymal lineage as defined by Paired related homeobox 1 (Prx). Here we demonstrate that Hypoxia inducible factor-1α (Hif1α), a key mediator of cellular adaptation to hypoxia, is highly expressed and active in three separate mouse models: trauma-induced, genetic, and a hybrid model of genetic and trauma-induced HO. In each of these models, Hif1α expression coincides with the expression of master transcription factor of cartilage, Sox9 [(sex determining region Y)-box 9]. Pharmacologic inhibition of Hif1α using PX-478 or rapamycin significantly decreased or inhibited extraskeletal bone formation. Importantly, de novo soft-tissue HO was eliminated or significantly diminished in treated mice. Lineage-tracing mice demonstrate that cells forming HO belong to the Prx lineage. Burn/tenotomy performed in lineage-specific Hif1α knockout mice (Prx-Cre/Hif1α(fl:fl)) resulted in substantially decreased HO, and again lack of de novo soft-tissue HO. Genetic loss of Hif1α in mesenchymal cells marked by Prx-cre prevents the formation of the mesenchymal condensations as shown by routine histology and immunostaining for Sox9 and PDGFRα. Pharmacologic inhibition of Hif1α had a similar effect on mesenchymal condensation development. Our findings indicate that Hif1α represents a promising target to prevent and treat pathologic extraskeletal bone.

In vivo high-resolution magic angle spinning magnetic and electron paramagnetic resonance spectroscopic analysis of mitochondria-targeted peptide in Drosophila melanogaster with trauma-induced thoracic injury.

Trauma is the most common cause of mortality among individuals aged between 1 and 44 years and the third leading cause of mortality overall in the US. In this study, we examined the effects of trauma on the expression of genes in Drosophila melanogaster, a useful model for investigating genetics and physiology. After trauma was induced by a non-lethal needle puncture of the thorax, we observed the differential expression of genes encoding for mitochondrial uncoupling proteins, as well as those encoding for apoptosis-related and insulin signaling-related proteins, thus indicating muscle functional dysregulation. These results prompted us to examine the link between insulin signaling and mitochondrial dysfunction using in vivo nuclear magnetic resonance (NMR) with complementary electron paramagnetic resonance (EPR) spectroscopy. Trauma significantly increased insulin resistance biomarkers, and the NMR spectral profile of the aged flies with trauma-induced thoracic injury resembled that of insulin-resistant chico mutant flies. In addition, the mitochondrial redox status, as measured by EPR, was significantly altered following trauma, indicating mitochondrial uncoupling. A mitochondria-targeted compound, Szeto-Schiller (SS)-31 that promotes adenosine triphosphate (ATP) synthesis normalized the NMR spectral profile, as well as the mitochondrial redox status of the flies with trauma-induced thoracic injury, as assessed by EPR. Based on these findings, we propose a molecular mechanism responsible for trauma-related mortality and also propose that trauma sequelae in aging are linked to insulin signaling and mitochondrial dysfunction. Our findings further suggest that SS-31 attenuates trauma-associated pathological changes.

Is Real-Time Feedback of Burn-Specific Patient-Reported Outcome Measures in Clinical Settings Practical and Useful? A Pilot Study Implementing the Young Adult Burn Outcome Questionnaire.

Long-term follow-up care of survivors after burn injuries can potentially be improved by the application of patient-reported outcome measures (PROMs). PROMs can inform clinical decision-making and foster communication between the patient and provider. There are no previous reports using real-time, burn-specific PROMs in clinical practice to track and benchmark burn recovery over time. This study examines the feasibility of a computerized, burn-specific PROM, the Young Adult Burn Outcome Questionnaire (YABOQ), with real-time benchmarking feedback in a burn outpatient practice. The YABOQ was redesigned for formatting and presentation purposes using images and transcribed to a computerized format. The redesigned questionnaire was administered to young adult burn survivors (ages 19-30 years, 1-24 months from injury) via an ipad platform in the office before outpatient visits. A report including recovery curves benchmarked to a nonburned relatively healthy age-matched population and to patients with similar injuries was produced for the domains of physical function and social function limited by appearance. A copy of the domain reports as well as a complete copy of the patient's responses to all domain questions was provided for use during the clinical visit. Patients and clinicians completed satisfaction surveys at the conclusion of the visit. Free-text responses, included in the satisfaction surveys, were treated as qualitative data adding contextual information about the assessment of feasibility. Eleven patients and their providers completed the study for 12 clinical visits. All patients found the ipad survey and report "easy" or "very easy" to use. In nine instances, patients "agreed" or "strongly agreed" that it helped them communicate their situation to their doctor/nurse practitioner. Patients "agreed" or "strongly agreed" that the report helped them understand their course of recovery in 10 visits. In 11 visits, the patients "agreed" or "strongly agreed" that they would recommend this feedback to others. Qualitative comments included: "it helped organize my thoughts of recovery," "it opened lines of communication with the doctor," "it showed me how far I have come, and how far I need to go," and "it raised questions I would not have thought of." Only four of 12 provider surveys agreed that it helped them understand a patient's condition; however, in two visits, the providers stated that it helped identify a pertinent clinical issue. During two visits, providers stated that a treatment plan was discussed or recommended based on the survey results. Separately, qualitative comments from the providers included "survey was not sensitive enough to identify that this patient needed surgery for their scars." This is the first report describing clinical use of a burn-specific patient reported outcome measure. Real-time feedback using the ipad YABOQ was well received for the most part by the clinicians and burn survivors in the outpatient clinic setting. The information provided by the reports can be tested in a future randomized controlled clinical study evaluating impacts on physician decisions.

Early leukocyte gene expression associated with age, burn size, and inhalation injury in severely burned adults.

BACKGROUND: In the patient with burn injury, older age, larger percentage of total body surface area (TBS) burned, and inhalation injury are established risk factors for death, which typically results from multisystem organ failure and sepsis, implicating burn-induced immune dysregulation as a contributory mechanism. We sought to identify early transcriptomic changes in circulating leukocytes underlying increased mortality associated with these three risk factors. METHODS: We performed a retrospective analysis of the Glue Grant database. From 2003 to 2010, 324 adults with 20% or greater TBS burned were prospectively enrolled at five US burn centers, and 112 provided blood samples within 1 week after burn. RNA was extracted from pooled leukocytes for hybridization onto Affymetrix HU133 Plus 2.0 GeneChips. A multivariate regression model was constructed to determine risk factors for mortality. Testing for differential gene association associated with age, burn size, and inhalation injury was based on linear models using a fold change threshold of 1.5 and false discovery rate of 0.05. RESULTS: After adjusting for potential confounders, age greater than 60 years (relative risk [RR], 4.53; 95% confidence interval [CI], 2.93-6.99), burn size greater than 40% TBS (RR, 4.24; 95% CI, 2.61-6.91), and inhalation injury (RR, 2.08; 95% CI, 1.35-3.21) were independently associated with mortality. No genes were differentially expressed in association with age greater than 60 years or inhalation injury. Fifty-one probe sets representing 39 unique genes were differentially expressed in leukocytes from patients with burn size greater than 40% TBS; these genes were associated with platelet activation and degranulation/exocytosis, and gene-set enrichment analysis suggested increased cellular proliferation and down-regulation of proinflammatory cytokines. CONCLUSION: Among adults with large burns, older age, increasing burn size, and inhalation injury have a modest effect on the leukocyte transcriptome in the context of the "genomic storm" induced by a 20% or greater than TBS burned. The 39-gene signature we identified may provide novel targets for the development of therapies to reduce morbidity and mortality associated with burns greater than 40% TBS. LEVEL OF EVIDENCE: Epidemiologic study, level III.

Role of protein farnesylation in burn-induced metabolic derangements and insulin resistance in mouse skeletal muscle.

OBJECTIVE: Metabolic derangements, including insulin resistance and hyperlactatemia, are a major complication of major trauma (e.g., burn injury) and affect the prognosis of burn patients. Protein farnesylation, a posttranslational lipid modification of cysteine residues, has been emerging as a potential component of inflammatory response in sepsis. However, farnesylation has not yet been studied in major trauma. To study a role of farnesylation in burn-induced metabolic aberration, we examined the effects of farnesyltransferase (FTase) inhibitor, FTI-277, on burn-induced insulin resistance and metabolic alterations in mouse skeletal muscle. METHODS: A full thickness burn (30% total body surface area) was produced under anesthesia in male C57BL/6 mice at 8 weeks of age. After the mice were treated with FTI-277 (5 mg/kg/day, IP) or vehicle for 3 days, muscle insulin signaling, metabolic alterations and inflammatory gene expression were evaluated. RESULTS: Burn increased FTase expression and farnesylated proteins in mouse muscle compared with sham-burn at 3 days after burn. Simultaneously, insulin-stimulated phosphorylation of insulin receptor (IR), insulin receptor substrate (IRS)-1, Akt and GSK-3ß was decreased. Protein expression of PTP-1B (a negative regulator of IR-IRS-1 signaling), PTEN (a negative regulator of Akt-mediated signaling), protein degradation and lactate release by muscle, and plasma lactate levels were increased by burn. Burn-induced impaired insulin signaling and metabolic dysfunction were associated with increased inflammatory gene expression. These burn-induced alterations were reversed or ameliorated by FTI-277. CONCLUSIONS: Our data demonstrate that burn increased FTase expression and protein farnesylation along with insulin resistance, metabolic alterations and inflammatory response in mouse skeletal muscle, all of which were prevented by FTI-277 treatment. These results indicate that increased protein farnesylation plays a pivotal role in burn-induced metabolic dysfunction and inflammatory response. Our study identifies FTase as a novel potential molecular target to reverse or ameliorate metabolic derangements in burn patients.

Survival from burns in the new millennium: 70 years' experience from a single institution.

OBJECTIVE: This review explores the series of published analyses from Massachusetts General Hospital to better understand how changes in medical specialization of burn medicine likely enabled the most important increase in survival from burns in the past 70 years. BACKGROUND: Seventy years ago, survival from the most serious burn injuries was not possible even in the most advanced countries until critical advances were introduced. Insights into those few medical advances that actually impacted survival might be better understood from the consideration of a continuous series of survival analyses over 7 decades at Massachusetts General Hospital. METHODS: Mortality data from previously reported probit and logit analyses from thousands of patients treated at Massachusetts General Hospital were reviewed. A comparison of mortality from these prior mortality analyses from a more recent multicenter study and a national data set was performed. RESULTS: The only giant leap forward in survival occurred during the 1970s, with no improvement during either the preceding or subsequent 30-year intervals. Despite the many modern advances that have been added to the care of these patients since 1984, although these may have represented medical progress, these advances did not impact survival. CONCLUSIONS: Survival rates from burn injury may have been maximized by current treatment approaches within medical centers of excellence in burn medicine. Further efforts to improve the quality of life of survivors of burn injury should ultimately have very favorable impact upon the long-term outcomes in these patients who now survive such devastating injuries.

Prediction of multiple infections after severe burn trauma: a prospective cohort study.

OBJECTIVE: To develop predictive models for early triage of burn patients based on hypersusceptibility to repeated infections. BACKGROUND: Infection remains a major cause of mortality and morbidity after severe trauma, demanding new strategies to combat infections. Models for infection prediction are lacking. METHODS: Secondary analysis of 459 burn patients (≥16 years old) with 20% or more total body surface area burns recruited from 6 US burn centers. We compared blood transcriptomes with a 180-hour cutoff on the injury-to-transcriptome interval of 47 patients (≤1 infection episode) to those of 66 hypersusceptible patients [multiple (≥2) infection episodes (MIE)]. We used LASSO regression to select biomarkers and multivariate logistic regression to built models, accuracy of which were assessed by area under receiver operating characteristic curve (AUROC) and cross-validation. RESULTS: Three predictive models were developed using covariates of (1) clinical characteristics; (2) expression profiles of 14 genomic probes; (3) combining (1) and (2). The genomic and clinical models were highly predictive of MIE status [AUROCGenomic = 0.946 (95% CI: 0.906-0.986); AUROCClinical = 0.864 (CI: 0.794-0.933); AUROCGenomic/AUROCClinical P = 0.044]. Combined model has an increased AUROCCombined of 0.967 (CI: 0.940-0.993) compared with the individual models (AUROCCombined/AUROCClinical P = 0.0069). Hypersusceptible patients show early alterations in immune-related signaling pathways, epigenetic modulation, and chromatin remodeling. CONCLUSIONS: Early triage of burn patients more susceptible to infections can be made using clinical characteristics and/or genomic signatures. Genomic signature suggests new insights into the pathophysiology of hypersusceptibility to infection may lead to novel potential therapeutic or prophylactic targets.