Association of Blood-Based Brain Injury Biomarker Concentrations With Outcomes After Pediatric Cardiac Arrest.

Importance: Families and clinicians have limited validated tools available to assist in estimating long-term outcomes early after pediatric cardiac arrest. Blood-based brain-specific biomarkers may be helpful tools to aid in outcome assessment. Objective: To analyze the association of blood-based brain injury biomarker concentrations with outcomes 1 year after pediatric cardiac arrest. Design, Setting, and Participants: The Personalizing Outcomes After Child Cardiac Arrest multicenter prospective cohort study was conducted in pediatric intensive care units at 14 academic referral centers in the US between May 16, 2017, and August 19, 2020, with the primary investigators blinded to 1-year outcomes. The study included 120 children aged 48 hours to 17 years who were resuscitated after cardiac arrest, had pre-cardiac arrest Pediatric Cerebral Performance Category scores of 1 to 3 points, and were admitted to an intensive care unit after cardiac arrest. Exposure: Cardiac arrest. Main Outcomes and Measures: The primary outcome was an unfavorable outcome (death or survival with a Vineland Adaptive Behavior Scales, third edition, score of <70 points) at 1 year after cardiac arrest. Glial fibrillary acidic protein (GFAP), ubiquitin carboxyl-terminal esterase L1 (UCH-L1), neurofilament light (NfL), and tau concentrations were measured in blood samples from days 1 to 3 after cardiac arrest. Multivariate logistic regression and area under the receiver operating characteristic curve (AUROC) analyses were performed to examine the association of each biomarker with outcomes on days 1 to 3. Results: Among 120 children with primary outcome data available, the median (IQR) age was 1.0 (0-8.5) year; 71 children (59.2%) were male. A total of 5 children (4.2%) were Asian, 19 (15.8%) were Black, 81 (67.5%) were White, and 15 (12.5%) were of unknown race; among 110 children with data on ethnicity, 11 (10.0%) were Hispanic, and 99 (90.0%) were non-Hispanic. Overall, 70 children (58.3%) had a favorable outcome, and 50 children (41.7%) had an unfavorable outcome, including 43 deaths. On days 1 to 3 after cardiac arrest, concentrations of all 4 measured biomarkers were higher in children with an unfavorable vs a favorable outcome at 1 year. After covariate adjustment, NfL concentrations on day 1 (adjusted odds ratio [aOR], 5.91; 95% CI, 1.82-19.19), day 2 (aOR, 11.88; 95% CI, 3.82-36.92), and day 3 (aOR, 10.22; 95% CI, 3.14-33.33); UCH-L1 concentrations on day 2 (aOR, 11.27; 95% CI, 3.00-42.36) and day 3 (aOR, 7.56; 95% CI, 2.11-27.09); GFAP concentrations on day 2 (aOR, 2.31; 95% CI, 1.19-4.48) and day 3 (aOR, 2.19; 95% CI, 1.19-4.03); and tau concentrations on day 1 (aOR, 2.44; 95% CI, 1.14-5.25), day 2 (aOR, 2.28; 95% CI, 1.31-3.97), and day 3 (aOR, 2.04; 95% CI, 1.16-3.57) were associated with an unfavorable outcome. The AUROC models were significantly higher with vs without the addition of NfL on day 2 (AUROC, 0.932 [95% CI, 0.877-0.987] vs 0.871 [95% CI, 0.793-0.949]; P = .02) and day 3 (AUROC, 0.921 [95% CI, 0.857-0.986] vs 0.870 [95% CI, 0.786-0.953]; P = .03). Conclusions and Relevance: In this cohort study, blood-based brain injury biomarkers, especially NfL, were associated with an unfavorable outcome at 1 year after pediatric cardiac arrest. Additional evaluation of the accuracy of the association between biomarkers and neurodevelopmental outcomes beyond 1 year is needed.

Use of Magnetic Resonance Imaging in Neuroprognostication After Pediatric Cardiac Arrest: Survey of Current Practices.

BACKGROUND: Use of magnetic resonance imaging (MRI) as a tool to aid in neuroprognostication after cardiac arrest (CA) has been described, yet details of specific indications, timing, and sequences are unknown. We aim to define the current practices in use of brain MRI in prognostication after pediatric CA. METHODS: A survey was distributed to pediatric institutions participating in three international studies. Survey questions related to center demographics, clinical practice patterns of MRI after CA, neuroimaging resources, and details regarding MRI decision support. RESULTS: Response rate was 31% (44 of 143). Thirty-four percent (15 of 44) of centers have a clinical pathway informing the use of MRI after CA. Fifty percent (22 of 44) of respondents reported that an MRI is obtained in nearly all patients with CA, and 32% (14 of 44) obtain an MRI in those who do not return to baseline neurological status. Poor neurological examination was reported as the most common factor (91% [40 of 44]) determining the timing of the MRI. Conventional sequences (T1, T2, fluid-attenuated inversion recovery, and diffusion-weighted imaging/apparent diffusion coefficient) are routinely used at greater than 97% of centers. Use of advanced imaging techniques (magnetic resonance spectroscopy, diffusion tensor imaging, and functional MRI) were reported by less than half of centers. CONCLUSIONS: Conventional brain MRI is a common practice for prognostication after CA. Advanced imaging techniques are used infrequently. The lack of standardized clinical pathways and variability in reported practices support a need for higher-quality evidence regarding the indications, timing, and acquisition protocols of clinical MRI studies.

The impact of postgraduate education in transition to practice programmes on new graduate nurses' knowledge and skills: A pre- post survey design.

BACKGROUND: Research indicates that nurses perceive postgraduate education to have a positive effect on their knowledge and practice. Many jurisdictions offer/require new graduate nurses to undertake postgraduate coursework however the consequences of this are not clear. OBJECTIVES: This research aims to determine the impact of completing a postgraduate course in clinical assessment on the capabilities of new graduate nurses. DESIGN: A two group pre/post design with a naturally occurring intervention employing an online questionnaire was used to gather data. SETTINGS: Two metropolitan hospitals in New Zealand delivering new graduate programmes, one inclusive of a postgraduate course and the other not. PARTICIPANTS: Eighty five nurses completed the questionnaire on commencement of the programme and fifty-two on completion of the programme. METHODS: An online questionnaire was administered to two new graduate cohorts, on commencement and completion of their new graduate programme. RESULTS: Results showed significant pre/post increases for four out of five factors for those who had completed a postgraduate course compared to only one significant increase for those who had not. In addition, when comparing the scores of the two groups there was no significant differences between groups on the pre-measures. However, on post measures there were significant differences with the postgraduate group scoring higher on three of the five subscales: Knowledge for Practice, Explaining Practice and Applied Diagnostic Reasoning. CONCLUSION: It is the author's belief that this is the first study that has attempted to quantify new graduate nurses' perceptions of their educational experience in their first year of practice and suggests that the inclusion of the postgraduate course enhanced knowledge for practice and diagnostic reasoning skills.

Serum Biomarkers of Regeneration and Plasticity are Associated with Functional Outcome in Pediatric Neurocritical Illness: An Exploratory Study.

BACKGROUND/OBJECTIVE: Pediatric neurocritical care survivorship is frequently accompanied by functional impairments. Lack of prognostic biomarkers is a barrier to early identification and management of impairment. We explored the association between blood biomarkers and functional impairment in children with acute acquired brain injury. METHODS: This study is a secondary analysis of a randomized control trial evaluating early versus usual care rehabilitation in the pediatric intensive care unit (PICU). Forty-four children (17 [39%] female, median age 11 [interquartile range 6-13] years) with acute acquired brain injury admitted to the PICU were studied. A single center obtained serum samples on admission days 0, 1, 3, 5, and the day closest to hospital discharge. Biomarkers relevant to brain injury (neuron specific enolase [NSE], S100b), inflammation (interleukin [IL-6], C-reactive protein), and regeneration (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor [VEGF]) were collected. Biomarkers were analyzed using a Luminex® bioassay. Functional status scale (FSS) scores were abstracted from the medical record. New functional impairment was defined as a (worse) FSS score at hospital discharge compared to pre-PICU (baseline). Individual biomarker fluorescence index (FI) values for each sample collection day were correlated with new functional impairment using Spearman rank correlation coefficient (ρ). Trends in repeated measures of biomarker FI over time were explored graphically, and the association between repeated measures of biomarker FI and new functional impairment was analyzed using covariate adjusted linear mixed-effect models. RESULTS: Functional impairment was inversely correlated with markers of regeneration and plasticity including BDNF at day 3 (ρ = - 0.404, p = .015), day 5 (ρ = - 0.549, p = 0.005) and hospital discharge (ρ = - 0.420, p = 0.026) and VEGF at day 1 (ρ = - 0.282, p = 0.008) and hospital discharge (ρ = - 0.378, p = 0.047), such that lower levels of both markers at each time point were associated with greater impairment. Similarly, repeated measures of BDNF and VEGF were inversely correlated with new functional impairment (B = - 0.001, p = 0.001 and B = - 0.001, p = 0.003, respectively). NSE, a biomarker of acute brain injury, showed a positive correlation between day 0 levels and new functional impairment (ρ = 0.320, p = 0.044). CONCLUSIONS: Blood-based biomarkers of regeneration and plasticity may hold prognostic utility for functional impairment among pediatric patients with neurocritical illness and warrant further investigation.

Early Protocolized Versus Usual Care Rehabilitation for Pediatric Neurocritical Care Patients: A Randomized Controlled Trial.

OBJECTIVE: s: Few feasibility, safety, and efficacy data exist regarding ICU-based rehabilitative services for children. We hypothesized that early protocolized assessment and therapy would be feasible and safe versus usual care in pediatric neurocritical care patients. DESIGN: Randomized controlled trial. SETTING: Three tertiary care PICUs in the United States. PATIENTS: Fifty-eight children between the ages of 3-17 years with new traumatic or nontraumatic brain insult and expected ICU admission greater than 48 hours. INTERVENTIONS: Early protocolized (consultation of physical therapy, occupational therapy, and speech and language therapy within 72 hr ICU admission, n = 26) or usual care (consultation per treating team, n = 32). MEASUREMENTS AND MAIN RESULTS: Primary outcomes were consultation timing, treatment type, and frequency of deferrals and safety events. Secondary outcomes included patient and family functional and quality of life outcomes at 6 months. Comparing early protocolized (n = 26) and usual care groups (n = 32), physical therapy was consulted during the hospital admission in 26 of 26 versus 28 of 32 subjects (p = 0.062) on day 2.4 ± 0.8 versus 7.7 ± 4.8 (p = 0.001); occupational therapy in 26 of 26 versus 23 of 32 (p = 0.003), on day 2.3 ± 0.6 versus 6.9 ± 4.8 (p = 0.001); and speech and language therapy in 26 of 26 versus 17 of 32 (p = 0.011) on day 2.3 ± 0.7 versus 13.0 ± 10.8 (p = 0.026). More children in the early protocolized group had consults and treatments occur in the ICU versus ward for all three services (all p < 0.001). Eleven sessions were discontinued early: nine during physical therapy and two during occupational therapy, none impacting patient outcome. There were no group differences in functional or quality of life outcomes. CONCLUSIONS: A protocol for early personalized rehabilitation by physical therapy, occupational therapy, and speech and language therapy in pediatric neurocritical care patients could be safely implemented and led to more ICU-based treatment sessions, accelerating the temporal profile and changing composition of interventions versus usual care, but not altering the total dose of rehabilitation.

Educating new graduate nurses in their first year of practice: The perspective and experiences of the new graduate nurses and the director of nursing.

New graduate nurses are the future of nursing and the education they receive as they transition into the workforce as a newly registered nurse is critical for building a suitably qualified nursing workforce that will adequately serve the future population. Variation exists in education programmes for new graduate nurses in their first year of practice which is known to impact on transition experience. A qualitative study using focus groups and semi-structured interviews was undertaken to explore the experiences and perceptions of New Graduate Nurses undertaking a new graduate programme and Directors of Nursing supporting them to complete the programme which may or may not have been inclusive of a postgraduate course (Masters Level). The findings of this study are in line with previous research and support the value of new graduate programmes but did reveal a lack of consensus in regards to the structure and content of such programmes. This study revealed some commonalities and challenges between the differing programmes but has identified the need for further research to establish the impact of postgraduate education in the first year of practice and how this impacts on nursing practice and patient care. There are numerous terms in the literature with reference to new graduate programmes; transition to practice programme, nurse entry to practice programme, first year of clinical practice programme, new graduate programme and early career nursing programme. For the purpose of this article the term Nurse Entry to Practice (NETP) will be used in reference to any form of new graduate programme.

Pathophysiology of Pediatric Multiple Organ Dysfunction Syndrome.

OBJECTIVE: To describe the pathophysiology associated with multiple organ dysfunction syndrome in children. DATA SOURCES: Literature review, research data, and expert opinion. STUDY SELECTION: Not applicable. DATA EXTRACTION: Moderated by an experienced expert from the field, pathophysiologic processes associated with multiple organ dysfunction syndrome in children were described, discussed, and debated with a focus on identifying knowledge gaps and research priorities. DATA SYNTHESIS: Summary of presentations and discussion supported and supplemented by relevant literature. CONCLUSIONS: Experiment modeling suggests that persistent macrophage activation may be a pathophysiologic basis for multiple organ dysfunction syndrome. Children with multiple organ dysfunction syndrome have 1) reduced cytochrome P450 metabolism inversely proportional to inflammation; 2) increased circulating damage-associated molecular pattern molecules from injured tissues; 3) increased circulating pathogen-associated molecular pattern molecules from infection or endogenous microbiome; and 4) cytokine-driven epithelial, endothelial, mitochondrial, and immune cell dysfunction. Cytochrome P450s metabolize endogenous compounds and xenobiotics, many of which ameliorate inflammation, whereas damage-associated molecular pattern molecules and pathogen-associated molecular pattern molecules alone and together amplify the cytokine production leading to the inflammatory multiple organ dysfunction syndrome response. Genetic and environmental factors can impede inflammation resolution in children with a spectrum of multiple organ dysfunction syndrome pathobiology phenotypes. Thrombocytopenia-associated multiple organ dysfunction syndrome patients have extensive endothelial activation and thrombotic microangiopathy with associated oligogenic deficiencies in inhibitory complement and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13. Sequential multiple organ dysfunction syndrome patients have soluble Fas ligand-Fas-mediated hepatic failure with associated oligogenic deficiencies in perforin and granzyme signaling. Immunoparalysis-associated multiple organ dysfunction syndrome patients have impaired ability to resolve infection and have associated environmental causes of lymphocyte apoptosis. These inflammation phenotypes can lead to macrophage activation syndrome. Resolution of multiple organ dysfunction syndrome requires elimination of the source of inflammation. Full recovery of organ functions is noted 6-18 weeks later when epithelial, endothelial, mitochondrial, and immune cell regeneration and reprogramming is completed.

Adaptive immune function in critical illness.

PURPOSE OF REVIEW: This review is being published to update the literature on the function of the adaptive immune system in critical illness, specifically sepsis and acute lung injury. We have focused on the role of T cells in these syndromes. RECENT FINDINGS: The adaptive immune response becomes dysfunctional during sepsis and acute lung injury in very similar ways. Many of the abnormalities contribute to morbidity and mortality. Immunoparalysis captures the breadth of the dysfunction in that T-cell functions are broadly suppressed after the early proinflammatory stages of illness. Lymphocyte apoptosis, decreased antigen responsiveness, decreased and altered cytokine expression, upregulation of inhibitory molecules, and expansion of the suppressive regulatory T-cell population are mechanisms involved. Each of these abnormalities can be reversed with improvement in experimental outcomes. SUMMARY: Immunoparalysis of the adaptive immune system occurs in sepsis and acute lung injury, and is critical to the outcome. Blocking the inhibited pathways and immunostimulant cytokines improved lymphocyte function and outcome. Many such blocking agents are already effective for other diseases and could be used for immunoparalysis. Unfortunately, there is no diagnostic marker yet. In order to provide the right therapy at the right time, advancements in immunomonitoring are necessary.

Reaching their potential: Perceived impact of a collaborative academic-clinical partnership programme for early career nurses in New Zealand.

BACKGROUND: The dynamic nature of healthcare ensures that early career nurses enter an uncertain and complex world of practice and consequently require support to develop their practice, build confidence and reach their potential. The New Zealand Nurse Entry to Practice programme for registered nurses in their first year of practice has been operating since 2005 to enable safe and confident practice, improve the quality of care, and positively impact on recruitment and retention. This academic and clinical programme was offered as a partnership between a university and a clinical provider with postgraduate academic credits gained. AIM: The aim of this study was to explore the perceived impact of postgraduate university education for early career nurses in one regional health area of New Zealand. METHODS: Participants were registered nurses who had completed the early career nurse programme and their clinical preceptors. The research was conducted via an online survey of 248 nurses and three focus groups to explore how the programme was experienced and its impact on knowledge and practice. RESULTS: Early career nurses and their preceptors found that the programme enables improved knowledge and skills of patient assessment, application of critical thinking to clinical practice, perceived improvement in patient care delivery and outcomes, enhanced interprofessional communication and knowledge sharing, and had a positive impact on professional awareness and career planning. CONCLUSIONS: This clinical-academic partnership positively impacted on the clinical practice and transition experience of early career nurses and was closely aligned to an organization's strategic plan for nursing workforce development.

Acute renal replacement therapy in pediatrics.

Acute kidney injury (AKI) independently increases morbidity and mortality in children admitted to the hospital. Renal replacement therapy (RRT) is an essential therapy in the setting of AKI and fluid overload. The decision to initiate RRT is complex and often complicated by concerns related to patient hemodynamic and thermodynamic instability. The choice of which RRT modality to use depends on numerous criteria that are both patient and treatment center specific. Surprisingly, despite decades of use, no randomized, controlled trial study involving RRT in pediatrics has been performed. Because of these factors, clear-cut consensus is lacking regarding key questions surrounding RRT delivery. In this paper, we will summarize existing data concerning RRT use in children. We discuss the major modalities and the data-driven specifics of each, followed by controversies in RRT. As no standard of care is in widespread use for RRT in AKI or in multiorgan disease, we conclude in this paper that prospective studies of RRT are needed to identify best practice guidelines.

Validation of a gene expression-based subclassification strategy for pediatric septic shock.

OBJECTIVE: Septic shock heterogeneity has important implications for clinical trial implementation and patient management. We previously addressed this heterogeneity by identifying three putative subclasses of children with septic shock based exclusively on a 100-gene expression signature. Here we attempted to prospectively validate the existence of these gene expression-based subclasses in a validation cohort. DESIGN: Prospective observational study involving microarray-based bioinformatics. SETTING: Multiple pediatric intensive care units in the United States. PATIENTS: Separate derivation (n = 98) and validation (n = 82) cohorts of children with septic shock. INTERVENTIONS: None other than standard care. MEASUREMENTS AND MAIN RESULTS: Gene expression mosaics of the 100 class-defining genes were generated for 82 individual patients in the validation cohort. Using computer-based image analysis, patients were classified into one of three subclasses ("A," "B," or "C") based on color and pattern similarity relative to reference mosaics generated from the original derivation cohort. After subclassification, the clinical database was mined for phenotyping. Subclass A patients had higher illness severity relative to subclasses B and C as measured by maximal organ failure, fewer intensive care unit-free days, and a higher Pediatric Risk of Mortality score. Patients in subclass A were characterized by repression of genes corresponding to adaptive immunity and glucocorticoid receptor signaling. Separate subclass assignments were conducted by 21 individual clinicians using visual inspection. The consensus classification of the clinicians had modest agreement with the computer algorithm. CONCLUSIONS: We have validated the existence of subclasses of children with septic shock based on a biologically relevant, 100-gene expression signature. The subclasses have relevant clinical differences.

Toward a clinically feasible gene expression-based subclassification strategy for septic shock: proof of concept.

OBJECTIVE: To develop a clinically feasible stratification strategy for pediatric septic shock, using gene expression mosaics and a 100-gene signature representing the first 24 hrs of admission to the pediatric intensive care unit. DESIGN: Prospective, observational study involving microarray-based bioinformatics. SETTING: Multiple pediatric intensive care units in the United States. PATIENTS: Ninety-eight children with septic shock. INTERVENTIONS: None other than standard care. MEASUREMENTS AND MAIN RESULTS: Patients were classified into three previously published, genome-wide, expression-based subclasses (subclasses A, B, and C) having clinically relevant phenotypic differences. The class-defining 100-gene signature was depicted for each individual patient, using mosaics generated by the Gene Expression Dynamics Inspector (GEDI). Composite mosaics were generated representing the average expression patterns for each of the three subclasses. Nine individual clinicians served as blinded evaluators. Each evaluator was shown the 98 individual patient mosaics and asked to classify each patient into one of the three subclasses, using the composite mosaics as the reference point. The respective sensitivities, specificities, positive predictive values, and negative predictive values of the subclassification strategy were ≥ 4% across the three subclasses. The classification strategy also generated positive likelihood ratios of ≥ 6.8 and negative likelihood ratios of ≤ .2 across the three subclasses. The κ coefficient across all possible interevaluator comparisons was 0.81. CONCLUSIONS: We have provided initial evidence (proof of concept) for a clinically feasible and robust stratification strategy for pediatric septic shock based on a 100-gene signature and gene expression mosaics.

Admission angiopoietin levels in children with septic shock.

Angiopoietin (angpt) 1 and angpt-2 are circulating proteins first ascribed opposing roles in embryonic angiogenesis. Both bind the tyrosine kinase with immunoglobulin-like loop and epidermal growth factor homology domains (Tie) 2 receptor on endothelial cells, but angpt-1 is a Tie-2 agonist, whereas angpt-2 antagonizes Tie-2 signaling. In the developed vasculature, angpt-1 protects against vascular leak, whereas angpt-2 promotes increased vascular permeability. Because alterations in vascular permeability are common in septic shock, we obtained plasma from critically ill children within 24 h of diagnosis of the systemic inflammatory response syndrome (SIRS, n = 20), sepsis (n = 20), or septic shock (n = 61), as well as 15 healthy controls. Plasma levels of angpt-1 and angpt-2 were measured via a commercially available enzyme-linked immunosorbent assay. Plasma angpt-2 levels were significantly elevated in children with septic shock when compared with healthy children, as well as critically ill children with either SIRS or sepsis, and circulating angpt-2 levels seemed to correlate with disease severity and outcome. In addition, plasma angpt-1 levels were significantly decreased in critically ill children with septic shock compared with critically ill children with either SIRS or sepsis. Given the contrasting effects of angpt-2 and angpt-1 on the vascular endothelium, these two factors may play an important role in the pathophysiology of septic shock in children, and further studies are warranted.

SOCS-1 is a central mediator of steroid-increased thymocyte apoptosis and decreased survival following sepsis.

Suppressor of Cytokine Signaling (SOCS) proteins are recently identified inhibitors/regulators of cytokine/growth factor signaling pathways. We have previously shown that SOCS-3 is upregulated in mice after sepsis induced by cecal ligation and puncture; however, the contribution of SOCS-1 to septic morbidity and mortality is unclear. In the present study, we characterized SOCS-1 expression in different tissues and delineated putative mechanisms effecting SOCS-1 expression in thymus from septic mice. We observed no difference in SOCS-1 expression in blood, peritoneal leukocytes, lung, and spleen taken from sham or septic animals at 24 h after surgery. In contrast, SOCS-1 expression in thymus declined significantly after sepsis and this down-regulation of SOCS-1 was associated with increased thymocyte apoptosis as well as augmented Bax recruitment to the mitochondria. Administration of RU-38486, a steroid receptor antagonist, reversed the above effects in the septic thymus. Furthermore, SOCS-1+/- mice showed a significant higher mortality when compared to SOCS-1+/+ mice after sepsis. Together, these results show that sepsis increases steroid-induced thymic lymphoid cell apoptosis, which is associated with reduced SOCS-1 expression and increased Bax translocation to mitochondria. Survival data suggests that SOCS-1 protein may play an important role in sepsis.

Activation of common antiviral pathways can potentiate inflammatory responses to septic shock.

Induction of the antiviral cytokine interferon alpha/beta (IFN-alpha/beta) is common in many viral infections. The impact of ongoing antiviral responses on subsequent bacterial infection is not well understood. In human disease, bacterial superinfection complicating a viral infection can result in significant morbidity and mortality. We injected mice with polyinosinic-polycytidylic (PIC) acid, a TLR3 ligand and known IFN-alpha/beta inducer as well as nuclear factor kappaB (NF-kappaB) activator to simulate very early antiviral pathways. We then challenged mice with an in vivo septic shock model characterized by slowly evolving bacterial infection to simulate bacterial superinfection early during a viral infection. Our data demonstrated robust induction of IFN-alpha in serum within 24 h of PIC injection with IFN-alpha/beta-dependent major histocompatibility antigen class II up-regulation on peritoneal macrophages. PIC pretreatment before septic shock resulted in augmented tumor necrosis factor alpha and interleukins 6 and 10 and heightened lethality compared with septic shock alone. Intact IFN-alpha/beta signaling was necessary for augmentation of the inflammatory response to in vivo septic shock and to both TLR2 and TLR4 agonists in vitro. To assess the NF-kappaB contribution to PIC-modulated inflammatory responses to septic shock, we treated with parthenolide, an NF-kappaB inhibitor before PIC and septic shock. Parthenolide did not inhibit IFN-alpha induction by PIC. Inhibition of NF-kappaB by parthenolide did reduce IFN-alpha-mediated potentiation of the cytokine response and lethality from septic shock. Our data demonstrate that pathways activated early during many viral infections can have a detrimental impact on the outcome of subsequent bacterial infection. These pathways may be critical to understanding the heightened morbidity and mortality from bacterial superinfection after viral infection in human disease.

In vivo delivery of caspase-8 or Fas siRNA improves the survival of septic mice.

Although studies have shown increased evidence of death receptor-driven apoptosis in intestinal lymphoid cells, splenocytes, and the liver following the onset of polymicrobial sepsis, little is known about the mediators controlling this process or their pathologic contribution. We therefore attempted to test the hypothesis that the hydrodynamic administration of small interfering RNA (siRNA) against the death receptor, Fas or caspase-8, should attenuate the onset of morbidity and mortality seen in sepsis, as produced by cecal ligation and puncture (CLP). We initially show that in vivo administration of green fluorescent protein (GFP) siRNA in GFP transgenic mice results in a decrease in GFP fluorescence in most tissues. Subsequently, we also found that treating septic nontransgenic mice with siRNA targeting Fas or caspase-8 but not GFP (used as a control here) decreased the mRNA, in a sustained fashion up to 10 days, and protein expression of Fas and caspase-8, respectively. In addition, transferase-mediated dUTP (deoxyuridine triphosphate) nick end labeling (TUNEL) and active caspase-3 analyses revealed a decrease in apoptosis in the liver and spleen but not the thymus following siRNA treatment. Indices of liver damage were also decreased. Finally, the injection of Fas or caspase-8 given not only 30 minutes but up to 12 hours after CLP significantly improved the survival of septic mice.

Differential effects of macrophage inflammatory chemokine-2 and keratinocyte-derived chemokine on hemorrhage-induced neutrophil priming for lung inflammation: assessment by adoptive cells transfer in mice.

Prior studies have shown that hemorrhage (Hem) can serve as a priming stimulus for acute lung injury (ALI) triggered by subsequent septic challenge (cecal ligation and puncture, CLP). Furthermore, we have reported that in vivo antibody neutralization of the chemokines, macrophage inflammatory chemokine-2 (MIP-2) and keratinocyte-derived chemokine (KC), immediately after Hem appears to differentially effect the onset of ALI. However, although we hypothesize that this is due to divergent effects of MIP-2 and KC on Hem-induced neutrophil (PMN) priming, this has not been tested. To examine this hypothesis, PMN donor mice were Sham-Hem or Hem for 90 min at 35 +/- 5 mmHg and were then administered anti-MIP- 2 (Hem/anti-MIP2), anti-KC (Hem/anti-KC), or nonspecific immunoglobulin (Ig) G (Hem/IgG) during resuscitation (Ringer's lactate = four times the amount of drawn blood volume). Twenty-four hours post-Hem, the peripheral blood PMN were purified from these donor animals and were introduced into PMN-depleted recipient mice [depleted by prior anti-Gr1 (mouse PMN-specific marker) antibody treatment]. One hour after PMN transfer, recipient mice were subjected to CLP, euthanized 24 h later, and plasma as well as lung tissue samples were collected. PMN influx was assessed by myeloperoxidase assay (MPO; microU/mg protein) and histologically (IL-6, MIP-2, KC, and IL-10 levels) by enzyme-linked immunoabsorbant assay (ELISA; ng/mg). The results show that donor PMN from Hem/IgG but not Sham-Hem mice produce increased PMN influx (increased MPO, increased % esterase+ cells in tissue) into the lung and local tissue inflammation (increased IL-6/MIP-2, decreased IL-10) in PMN-depleted CLP recipient mice, which was attenuated in mice receiving cells from Hem/anti-MIP-2 but not Hem/anti-KC treated donors. Interestingly, although Hem/anti-MIP-2 donor PMN produced comparable effects on blood IL-6/MIP-2 levels, they were ineffective in altering the change in plasma IL-10/KC levels induce by Hem. Taken together, these data demonstrate that Hem-induced priming of PMN not only mediates ALI in the mouse, but also that this process is differentially effected by MIP2 and KC, despite the fact that both signal through CXCR2.

Cytochrome P450 mediated-drug metabolism is reduced in children with sepsis-induced multiple organ failure.

OBJECTIVE: Antipyrine metabolism is a "gold standard" measure of mixed cytochrome P450 (CYP) mediated drug metabolism in humans. Cytokines (e.g., interleukin-6) and nitric oxide reduce CYP 450 activity in vitro and in vivo. Because interleukin-6 and nitric oxide production increases in children with sepsis-induced multiple organ failure, we hypothesized impaired CYP 450 mediated drug metabolism in this population. METHODS: Fifty-one consecutive children with sepsis and six critically ill children without sepsis were enrolled and given 18 mg/kg antipyrine per NG. Plasma antipyrine elimination rate, elimination half-life, and apparent oral clearance were measured and calculated. Plasma interleukin-6 and nitrite plus nitrate levels were measured and organs failing scored on days 1-3 of sepsis. RESULTS: Children with sepsis had a twofold reduction in antipyrine clearance. Children with persistent failure of three or more organs had a fourfold reduction in antipyrine clearance. Antipyrine clearance was inversely correlated to circulating interleukin-6 and nitrite plus nitrate levels and to number of organ failures. CONCLUSIONS: Interpretation CYP 450 mediated drug metabolism is decreased in children with sepsis, related in part to the degree of inflammation and organ failure. For drugs metabolized by CYP 450 enzymes there is an urgent need to reevaluate the use of standard drug dosage schedules in the sepsis population