Burn Injury Reduces Neutrophil Directional Migration Speed in Microfluidic Devices

Thermal injury triggers a fulminant inflammatory cascade that heralds shock, end-organ failure, and ultimately sepsis and death. Emerging evidence points to a critical role for the innate immune system, and several studies had documented concurrent impairment in neutrophil chemotaxis with these post-burn inflammatory changes. While a few studies suggest that a link between neutrophil motility and patient mortality might exist, so far, cumbersome assays have prohibited exploration of the prognostic and diagnostic significance of chemotaxis after burn injury. To address this need, we developed a microfluidic device that is simple to operate and allows for precise and robust measurements of chemotaxis speed and persistence characteristics at single-cell resolution. Using this assay, we established a reference set of migration speed values for neutrophils from healthy subjects. Comparisons with samples from burn patients revealed impaired directional migration speed starting as early as 24 hours after burn injury, reaching a minimum at 72–120 hours, correlated to the size of the burn injury and potentially serving as an early indicator for concurrent infections. Further characterization of neutrophil chemotaxis using this new assay may have important diagnostic implications not only for burn patients but also for patients afflicted by other diseases that compromise neutrophil functions

Functional Genomics Unique to Week 20 Post Wounding in the Deep Cone/Fat Dome of the Duroc/Yorkshire Porcine Model of Fibroproliferative Scarring

Background: Hypertrophic scar was first described over 100 years ago; PubMed has more than 1,000 references on the topic. Nevertheless prevention and treatment remains poor, because 1) there has been no validated animal model; 2) human scar tissue, which is impossible to obtain in a controlled manner, has been the only source for study; 3) tissues typically have been homogenized, mixing cell populations; and 4) gene-by-gene studies are incomplete.Methodology/Principal Findings: We have assembled a system that overcomes these barriers and permits the study of genome-wide gene expression in microanatomical locations, in shallow and deep partial-thickness wounds, and pigmented and non-pigmented skin, using the Duroc( pigmented fibroproliferative)/Yorkshire( non-pigmented non-fibroproliferative) porcine model. We used this system to obtain the differential transcriptome at 1, 2, 3, 12 and 20 weeks post wounding. It is not clear when fibroproliferation begins, but it is fully developed in humans and the Duroc breed at 20 weeks. Therefore we obtained the derivative functional genomics unique to 20 weeks post wounding. We also obtained long-term, forty-six week follow-up with the model.Conclusions/Significance: 1) the scars are still thick at forty-six weeks post wounding further validating the model. 2) the differential transcriptome provides new insights into the fibroproliferative process as several genes thought fundamental to fibroproliferation are absent and others differentially expressed are newly implicated. 3) the findings in the derivative functional genomics support old concepts, which further validates the model, and suggests new avenues for reductionist exploration. in the future, these findings will be searched for directed networks likely involved in cutaneous fibroproliferation. These clues may lead to a better understanding of the systems biology of cutaneous fibroproliferation, and ultimately prevention and treatment of hypertrophic scarring.The National Institute on Disability and Rehabilitation ResearchThe National Institutes of HealthThe Washington State Council of Fire Fighters Burn FoundationThe Northwest Burn FoundationUniv Washington, Dept Surg, Div Plast Surg, Seattle, WA 98195 USAIowa State Univ, Dept Anim Sci, Ames, IA USAUniv Washington, Dept Biostat, Seattle, WA 98195 USAMahidol Univ, Ramathibodi Hosp, Dept Surg, Bangkok 10700, ThailandUniv Washington, Dept Environm & Occupat Hlth Sci, Seattle, WA 98195 USAUniversidade Federal de São Paulo, Div Plast Surg, Dept Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Div Plast Surg, Dept Surg, São Paulo, BrazilThe National Institute on Disability and Rehabilitation Research: H133G050022The National Institutes of Health: 1R21GM074673The National Institutes of Health: 5U54GM062119-09Web of Scienc

Management of intra-abdominal infections : recommendations by the WSES 2016 consensus conference

This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.Peer reviewe

Concomitant bacteraemia as a risk factor for diarrhoeal disease mortality in Karachi: a case-control study of hospitalized children

The objective of this study was to evaluate risk factors for death due to diarrhoea among hospitalized children at the Aga Khan University Hospital (AKUH), Karachi. We conducted a retrospective case-control study of all diarrhoea deaths at AKUH over the period 1988-93. For each death, the next two consecutive admissions matched for gender and type of diarrhoea were identified as controls. Data were analysed by univariate methods and logistic regression analysis. A total of 42 deaths and 84 matched controls were identified. Blood cultures at admission were obtained in all deaths and 94% of controls. The rates of isolation of organisms from blood cultures were significantly higher among deaths [38 versus 9%, odds ratio (OR) 6.5, 95% confidence interval (CI) 2.2-19.9], the majority of which were Gram-negative Enterobacteriaceae (94 versus 57%, Fisher\u27s exact test p \u3c 0.02). Conditional logistic regression revealed that several clinical and laboratory features of systemic infection were associated with a significantly increased risk of mortality, such as anorexia (OR 3.9, 95% CI 1.4-10.9), drowsiness (OR 4.4, 95% CI 1.3-15.3), respiratory distress (OR 7.0, 95% CI 1.4 36.6), anaemia (OR 5.8, 95% CI 2.0-16.6) and a positive blood culture (OR 8.7, 95% CI 2.5-30.7). Our data suggest that bacteraemia with Enterobacteriaceae is common among hospitalized malnourished children with diarrhoea and systemic infection may be an important risk factor for mortality