Clinical evaluation of the Life Support for Trauma and Transport (LSTAT) platform

INTRODUCTION: The Life Support for Trauma and Transport (LSTAT™) is a self-contained, stretcher-based miniature intensive care unit designed by the United States Army to provide care for critically injured patients during transport and in remote settings where resources are limited. The LSTAT contains conventional medical equipment that has been integrated into one platform and reduced in size to fit within the dimensional envelope of a North Atlantic Treaty Organization (NATO) stretcher. This study evaluated the clinical utility of the LSTAT in simulated and real clinical environments. Our hypothesis was that the LSTAT would be equivalent to conventional equipment in detecting and treating life-threatening problems. METHODS: Thirty-one anesthesiologists and recovery room nurses compared the LSTAT with conventional monitors while managing four simulated critical events. The time required to reach a diagnosis and treatment was recorded for each simulation. Subsequently, 10 consenting adult patients were placed on the LSTAT after surgery for postoperative care in the recovery room. Questionnaires about aspects of LSTAT functionality were completed by nine nurses who cared for the patients placed on the LSTAT. RESULTS: In all of the simulations, there was no clinically significant difference in the time to diagnosis or treatment between the LSTAT and conventional equipment. All clinicians reported that they were able to manage the simulated patients properly with the LSTAT. Nursing staff reported that the LSTAT provided adequate equipment to care for the patients monitored during recovery from surgery and were able to detect critical changes in vital signs in a timely manner. DISCUSSION: Preliminary evaluation of the LSTAT in simulated and postoperative environments demonstrated that the LSTAT provided appropriate equipment to detect and manage critical events in patient care. Further work in assessing LSTAT functionality in a higher-acuity environment is warranted

Preparation of Radiation-grafted Powders for use as Anion Exchange Ionomers in Alkaline Polymer Electrolyte Fuel Cells

A novel alkaline exchange ionomer (AEI) was prepared from the radiation-grafting of vinylbenzyl chloride (VBC) onto poly(ethylene-co-tetrafluoroethylene) [ETFE] powders with powder particle sizes of less than 100 μm diameter. Quaternisation of the VBC grafted ETFE powders with trimethylamine resulted in AEIs that were chemically the same as the ETFE-based radiation-grafted alkaline anion exchange membranes (AAEM) that had been previously developed for use in low temperature alkaline polymer electrolyte fuel cells (APEFC). The integration of the AEI powders into the catalyst layers (CL) of both electrodes resulted in a H2/O2 fuel cell peak power density of 240 mW cm−2 at 50 °C (compared to 180 mW cm−2 with a benchmark membrane electrode assembly containing identical components apart from the use of a previous generation AEI). This result is promising considering the wholly un-optimised nature of the AEI inclusion into the catalyst layers

Effects of short-term experimental manipulation of captive social environment on uropygial gland microbiome and preen oil volatile composition

IntroductionAvian preen oil, secreted by the uropygial gland, is an important source of volatile compounds that convey information about the sender’s identity and quality, making preen oil useful for the recognition and assessment of potential mates and rivals. Although intrinsic factors such as hormone levels, genetic background, and diet can affect preen oil volatile compound composition, many of these compounds are not the products of the animal’s own metabolic processes, but rather those of odor-producing symbiotic microbes. Social behavior affects the composition of uropygial microbial communities, as physical contact results in microbe sharing. We experimentally manipulated social interactions in captive dark-eyed juncos (Junco hyemalis) to assess the relative influence of social interactions, subspecies, and sex on uropygial gland microbial composition and the resulting preen oil odor profiles.MethodsWe captured 24 birds at Mountain Lake Biological Station in Virginia, USA, including birds from two seasonally sympatric subspecies – one resident, one migratory. We housed them in an outdoor aviary in three phases of social configurations: first in same-sex, same-subspecies flocks, then in male-female pairs, and finally in the original flocks. Using samples taken every four days of the experiment, we characterized their uropygial gland microbiome through 16S rRNA gene sequencing and their preen oil volatile compounds via GC-MS.ResultsWe predicted that if social environment was the primary driver of uropygial gland microbiome composition, and if microbiome composition in turn affected preen oil volatile profiles, then birds housed together would become more similar over time. Our results did not support this hypothesis, instead showing that sex and subspecies were stronger predictors of microbiome composition. We observed changes in volatile compounds after the birds had been housed in pairs, which disappeared after they were moved back into flocks, suggesting that hormonal changes related to breeding condition were the most important factor in these patterns.DiscussionAlthough early life social environment of nestlings and long-term social relationships have been shown to be important in shaping uropygial gland microbial communities, our study suggests that shorter-term changes in social environment do not have a strong effect on uropygial microbiomes and the resulting preen oil volatile compounds

Excision repair is required for genotoxin-induced mutagenesis in mammalian cells

Certain hexavalent chromium [Cr(VI)] compounds are human lung carcinogens. Although much is known about Cr-induced DNA damage, very little is known about mechanisms of Cr(VI) mutagenesis and the role that DNA repair plays in this process. Our goal was to investigate the role of excision repair (ER) pathways in Cr(VI)-mediated mutagenesis in mammalian cells. Repair-proficient Chinese hamster ovary cells (AA8), nucleotide excision repair (NER)-deficient (UV-5) and base excision repair (BER)-inhibited cells were treated with Cr(VI) and monitored for forward mutation frequency at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus. BER was inhibited using methoxyamine hydrochloride (Mx), which binds to apurinic/apyrimidinic sites generated during BER. Notably, we found that both NER-deficient (UV-5 and UV-41) and BER-inhibited (AA8 + Mx) cells displayed attenuated Cr(VI) mutagenesis. To determine whether this was unique to Cr(VI), we included the alkylating agent, methylmethane sulfonate (MMS) and ultraviolet (UV) radiation (260 nm) in our studies. Similar to Cr(VI), UV-5 cells exhibited a marked attenuation of MMS mutagenesis, but were hypermutagenic following UV exposure. Moreover, UV-5 cells expressing human xeroderma pigmentosum complementation group D displayed similar sensitivity to Cr(VI) and MMS-induced mutagenesis as AA8 controls, indicating that the genetic loss of NER was responsible for attenuated mutagenesis. Interestingly, Cr(VI)-induced clastogenesis was also attenuated in NER-deficient and BER-inhibited cells. Taken together, our results suggest that NER and BER are required for Cr(VI) and MMS-induced genomic instability. We postulate that, in the absence of ER, DNA damage is channeled into an error-free system of DNA repair or damage tolerance

AFM Visualization of Mobile Influenza A M2 Molecules in Planar Bilayers

We report the observation of influenza A M2 (M2) incorporated in a dipalmitoylphosphatidylcholine (DPPC) supported planar bilayer on mica, formed by use of a modified vesicle fusion method from proteoliposomes and visualized with contact mode atomic force microscopy. Incubation of proteoliposomes in a hyperosmotic solution and increased DPPC/M2 weight ratios improved supported planar bilayer formation by M2/DPPC proteoliposomes. M2's extra-bilayer domains were observed as particles estimated to protrude 1–1.5 nm above the bilayer surface and <4 nm in diameter. Particle density was 5–18% of the nominal tetramer density. Movement of observable M2 particles was independent of the probe tip. The mean lateral diffusion coefficient (D) of M2 was 4.4 ± 1.0 × 10(−14) cm(2)/s. Eighty-two percent of observable particles were mobile on the observable timescale (D > 6 × 10(−15) cm(2)/s). Protein-protein interactions were also observed directly