Damage control operations in non-trauma patients: Defining criteria for the staged rapid source control laparotomy in emergency general surgery

Background: The staged laparotomy in the operative management of emergency general surgery (EGS) patients is an extension of trauma surgeons operating on this population. Indications for its application, however, are not well defined, and are currently based on the lethal triad used in physiologically-decompensated trauma patients. This study sought to determine the acute indications for the staged, rapid source control laparotomy (RSCL) in EGS patients. Methods: All EGS patients undergoing emergent staged RSCL and non-RSCL over 3years were studied. Demographics, physiologic parameters, perioperative variables, outcomes, and survival were compared. Logistic regression models determined the influence of physiologic parameters on mortality and postoperative complications. EGS-RSCL indications were defined. Results: 215 EGS patients underwent emergent laparotomy; 53 (25%) were staged RSCL. In the 53 patients who underwent a staged RSCL based on the lethal triad, adjusted multivariable regression analysis shows that when used alone, no component of the lethal triad independently improved survival. Staged RSCL may decrease mortality in patients with preoperative severe sepsis / septic shock, and an elevated lactate (≥3); acidosis (pH ≤ 7.25); elderly (≥70); male gender; and multiple comorbidities (≥3). Of the 162 non-RSCL emergent laparotomies, 27 (17%) required unplanned re-explorations; of these, 17 (63%) had sepsis preoperatively and 9 (33%) died. Conclusions: The acute physiologic indicators that help guide operative decisions in trauma may not confer a similar survival advantage in EGS. To replace the lethal triad, criteria for application of the staged RSCL in EGS need to be defined. Based on these results, the indications should include severe sepsis / septic shock, lactate, acidosis, gender, age, and pre-existing comorbidities. When correctly applied, the staged RSCL may help to improve survival in decompensated EGS patients

Phase transitions in biological membranes

Native membranes of biological cells display melting transitions of their lipids at a temperature of 10-20 degrees below body temperature. Such transitions can be observed in various bacterial cells, in nerves, in cancer cells, but also in lung surfactant. It seems as if the presence of transitions slightly below physiological temperature is a generic property of most cells. They are important because they influence many physical properties of the membranes. At the transition temperature, membranes display a larger permeability that is accompanied by ion-channel-like phenomena even in the complete absence of proteins. Membranes are softer, which implies that phenomena such as endocytosis and exocytosis are facilitated. Mechanical signal propagation phenomena related to nerve pulses are strongly enhanced. The position of transitions can be affected by changes in temperature, pressure, pH and salt concentration or by the presence of anesthetics. Thus, even at physiological temperature, these transitions are of relevance. There position and thereby the physical properties of the membrane can be controlled by changes in the intensive thermodynamic variables. Here, we review some of the experimental findings and the thermodynamics that describes the control of the membrane function.Comment: 23 pages, 15 figure

Oral health and social and emotional well-being in a birth cohort of Aboriginal Australian young adults

Background: Social and emotional well-being is an important component of overall health. In the Indigenous Australian context, risk indicators of poor social and emotional well-being include social determinants such as poor education, employment, income and housing as well as substance use, racial discrimination and cultural knowledge. This study sought to investigate associations between oral health-related factors and social and emotional well-being in a birth cohort of young Aboriginal adults residing in the northern region of Australia's Northern Territory. Methods: Data were collected on five validated domains of social and emotional well-being: anxiety, resilience, depression, suicide and overall mental health. Independent variables included socio-demographics, dental health behaviour, dental disease experience, oral health-related quality of life, substance use, racial discrimination and cultural knowledge. Results: After adjusting for other covariates, poor oral health-related items were associated with each of the social and emotional well-being domains. Specifically, anxiety was associated with being female, having one or more decayed teeth and racial discrimination. Resilience was associated with being male, having a job, owning a toothbrush, having one or more filled teeth and knowing a lot about Indigenous culture; while being female, having experienced dental pain in the past year, use of alcohol, use of marijuana and racial discrimination were associated with depression. Suicide was associated with being female, having experience of untreated dental decay and racial discrimination; while being female, having experience of dental disease in one or more teeth, being dissatisfied about dental appearance and racial discrimination were associated with poor mental health. Conclusion: The results suggest there may be value in including oral health-related initiatives when exploring the role of physical conditions on Indigenous social and emotional well-being.Lisa M Jamieson, Yin C Paradies, Wendy Gunthorpe, Sheree J Cairney and Susan M Sayer

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients

Functional oligosaccharides: application and manufacture.

Oligosaccharides are attracting increasing interest as prebiotic functional food ingredients. They can be extracted or obtained by enzymatic hydrolysis from a variety of biomass sources or synthesized from simple oligosaccharides by enzymatic transfer reactions. The major prebiotic oligosaccharides on the market are inulin, fructo-oligosaccharides, and galacto-oligosaccharides. They have been evaluated using a range of in vitro and in vivo methods, although there is a need for more large-scale human trials using modern microbiological methods. Prebiotics are being studied for their effects on gut health and well being and specific clinical conditions, including colon cancer, inflammatory bowel disease (IBD), acute infections, and mineral absorption. Developing understanding of the functional ecology of the human gut is influencing current thinking on what a prebiotic might achieve and is providing new targets for prebiotic intervention

Computational redesign of a mononuclear zinc metalloenzyme for organophosphate hydrolysis.

The ability to redesign enzymes to catalyze noncognate chemical transformations would have wide-ranging applications. We developed a computational method for repurposing the reactivity of metalloenzyme active site functional groups to catalyze new reactions. Using this method, we engineered a zinc-containing mouse adenosine deaminase to catalyze the hydrolysis of a model organophosphate with a catalytic efficiency (k cat/K m) of ~10 4 M −1 s −1 after directed evolution. In the high-resolution crystal structure of the enzyme, all but one of the designed residues adopt the designed conformation. The designed enzyme efficiently catalyzes the hydrolysis of the R P isomer of a coumarinyl analog of the nerve agent cyclosarin, and it shows marked substrate selectivity for coumarinyl leaving groups. Computational redesign of native enzyme active sites complements directed evolution methods and offers a general approach for exploring their untapped catalytic potential for new reactivities. The redeployment of catalytic machinery in naturally occurring enzyme active sites for noncognate reactions holds considerable promise as a method for obtaining new biocatalysts 1,2. Alterations of substrate specificity and stereospecificity and the enhancement of preexisting promiscuous activities of enzymes have been accomplished by library-based directed evolution approaches 3. However, introducing completely new catalytic activities remains