Genes required for survival in microgravity revealed by genome-wide yeast deletion collections cultured during spaceflight.

Spaceflight is a unique environment with profound effects on biological systems including tissue redistribution and musculoskeletal stresses. However, the more subtle biological effects of spaceflight on cells and organisms are difficult to measure in a systematic, unbiased manner. Here we test the utility of the molecularly barcoded yeast deletion collection to provide a quantitative assessment of the effects of microgravity on a model organism. We developed robust hardware to screen, in parallel, the complete collection of ~4800 homozygous and ~5900 heterozygous (including ~1100 single-copy deletions of essential genes) yeast deletion strains, each carrying unique DNA that acts as strain identifiers. We compared strain fitness for the homozygous and heterozygous yeast deletion collections grown in spaceflight and ground, as well as plus and minus hyperosmolar sodium chloride, providing a second additive stressor. The genome-wide sensitivity profiles obtained from these treatments were then queried for their similarity to a compendium of drugs whose effects on the yeast collection have been previously reported. We found that the effects of spaceflight have high concordance with the effects of DNA-damaging agents and changes in redox state, suggesting mechanisms by which spaceflight may negatively affect cell fitness.

Accuracy of initial critical care triage decisions in blast versus non-blast trauma.

ABSTRACT OBJECTIVE: We investigated the accuracy of initial critical care triage in blast-injured versus non-blast-injured trauma patients, focusing on those inappropriately triaged to the intensive care unit (ICU) for brief (<16 h) stays. METHODS: We conducted a retrospective review of the Israel National Trauma Registry, applying a predetermined definition of need for initial ICU admission. RESULTS: A total of 883 blast-injured and 112 185 non-blast-injured patients were categorized according to their need for ICU admission. Of these admissions, 5.7% in the blast setting and 8.4% in the non-blast setting were considered unnecessary. The sensitivity, specificity, and positive and negative likelihood ratios for the triage officers' decisions in assigning patients to the ICU were 95.5%, 98.8%, 77.2, and 0.05, respectively, in the blast setting, and 91.2%, 99.5%, 200.5, and 0.09, respectively, in the non-blast setting. CONCLUSIONS: Triage officers do a better job sending to the ICU only those patients who require initial intensive care in the non-blast setting, though this is obscured by a much greater overall need for ICU-level care in the blast setting. Implementing triage protocols in the blast setting may help reduce the number of patients sent initially to the ICU for brief periods, thus increasing the availability of this resource.

Effects of microgravity on the virulence of Listeria monocytogenes, Enterococcus faecalis, Candida albicans, and methicillin-resistant Staphylococcus aureus.

To evaluate effects of microgravity on virulence, we studied the ability of four common clinical pathogens--Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, and Candida albicans--to kill wild type Caenorhabditis elegans (C. elegans) nematodes at the larval and adult stages. Simultaneous studies were performed utilizing spaceflight, clinorotation in a 2-D clinorotation device, and static ground controls. The feeding rate of worms for killed E. coli was unaffected by spaceflight or clinorotation. Nematodes, microbes, and growth media were separated until exposed to true or modeled microgravity, then mixed and grown for 48 h. Experiments were terminated by paraformaldehyde fixation, and optical density measurements were used to assay residual microorganisms. Spaceflight was associated with reduced virulence for Listeria, Enterococcus, MRSA, and Candida for both larval and adult C. elegans. These are the first data acquired with a direct in vivo assay system in space to demonstrate virulence. Clinorotation reproduced the effects of spaceflight in some, but not all, virulence assays: Candida and Enterococcus were less virulent for larval worms but not adult worms, whereas virulence of MRSA and Listeria were unaffected by clinorotation in tests with both adult and larval worms. We conclude that four common clinical microorganisms are all less virulent in space.

Disasters and mass casualties: II. explosive, biologic, chemical, and nuclear agents.

Terrorists' use of explosive, biologic, chemical, and nuclear agents constitutes the potential for catastrophic events. Understanding the unique aspects of these agents can help in preparing for such disasters with the intent of mitigating injury and loss of life. Explosive agents continue to be the most common weapons of terrorists and the most prevalent cause of injuries and fatalities. Knowledge of blast pathomechanics and patterns of injury allows for improved diagnostic and treatment strategies. A practical understanding of potential biologic, chemical, and nuclear agents, their attendant clinical symptoms, and recommended management strategies is an important prerequisite for optimal preparation and response to these less frequently used agents of mass casualty. Orthopaedic surgeons should be aware of the principles of management of catastrophic events. Stress is less an issue when one is adequately prepared. Decontamination is essential both to manage victims and prevent further spread of toxic agents to first responders and medical personnel. It is important to assess the risk of potential threats, thereby allowing disaster planning and preparation to be proportional and aligned with the actual casualty event.

Disasters and mass casualties: I. General principles of response and management.

Disaster planning and response to a mass casualty incident pose unique demands on the medical community. Because they would be required to confront many casualties with bodily injury and surgical problems, surgeons in particular must become better educated in disaster management. Compared with routine practice, triage principles in disasters require an entirely different approach to evaluation and care and often run counter to training and ethical values. An effective response to disaster and mass casualty events should focus on an "all hazards" approach, defined as the ability to adapt and apply fundamental disaster management principles universally to any mass casualty incident, whether caused by people or nature. Organizational tools such as the Incident Command System and the Hospital Incident Command System help to effect a rapid and coordinated response to specific situations. The United States federal government, through the National Response Plan, has the responsibility to respond quickly and efficiently to catastrophic incidents and to ensure critical life-saving assistance. International medical surgical response teams are capable of providing medical, surgical, and intensive care services in austere environments anywhere in the world.

An update on the surgeons scope and depth of practice to all hazards emergency response.

This article outlines the position of The Eastern Association of the Surgery of Trauma (EAST) in defining the role of surgeons, and specifically trauma/critical care surgeons, in the development of public health initiatives that are designed to react to and deal effectively with acts of terrorism. All aspects of the surgeon's role in response to mass casualty incidents are considered, from prehospital response teams to the postevent debriefing. The role of the surgeon in response to mass casualty incidents (MCIs) is substantial in response to threats and injury from natural, unintentional, and intentional disasters. The surgeon must take an active role in pre-event community preparation in training, planning, and executing the response to MCI. The marriage of initiatives among Departments of Public Health, the Department of Homeland Security, and existing trauma systems will provide a template for successful responses to terrorist acts.