Showing papers by "Defence Science and Technology Laboratory published in 2013"

Exploitation of bacterial N-linked glycosylation to develop a novel recombinant glycoconjugate vaccine against Francisella tularensis.

Abstract: Glycoconjugate-based vaccines have proved to be effective at producing long-lasting protection against numerous pathogens. Here, we describe the application of bacterial protein glycan coupling technology (PGCT) to generate a novel recombinant glycoconjugate vaccine. We demonstrate the conjugation of the Francisella tularensis O-antigen to the Pseudomonas aeruginosa carrier protein exotoxin A using the Campylobacter jejuni PglB oligosaccharyltransferase. The resultant recombinant F. tularensis glycoconjugate vaccine is expressed in Escherichia coli where yields of 3 mg l(-1) of culture were routinely produced in a single-step purification process. Vaccination of BALB/c mice with the purified glycoconjugate boosted IgG levels and significantly increased the time to death upon subsequent challenge with F. tularensis subsp. holarctica. PGCT allows different polysaccharide and protein combinations to be produced recombinantly and could be easily applicable for the production of diverse glycoconjugate vaccines.

Biological markers of exposure to organophosphorus nerve agents

Abstract: Organophosphorus nerve agents are the most toxic chemical warfare agents that are known to have been produced, stockpiled and weaponised. Their development, production, stockpiling and use are prohibited under the terms of the Chemical Weapons Convention and, together with their precursors, are subject to strict controls and verification procedures. The detection and identification of biological markers of exposure to nerve agents are required for three main purposes: confirmation of exposure for forensic purposes in cases of alleged use; diagnosis to guide appropriate medical countermeasures in the event of an exposure; and occupational health monitoring of workers in defence laboratories and demilitarisation facilities. Biomarkers of nerve agents fall into two main groups, free metabolites and adducts to proteins. These are reviewed together with analytical methods for their identification. Examples are provided of applications in cases of human exposure.

Utility of interim ROTEM® values of clot strength, A5 and A10, in predicting final assessment of coagulation status in severely injured battle patients

Abstract: Background Proactive management of trauma-related coagulopathy requires early identification and rapid assessment in order to allow targeted resuscitation This study determined whether early (interim) ROTEM ® (TEM International GmbH, Munich, Germany) values could predict hypocoagulopathy in seriously injured military patients Methods Normal ranges for ROTEM ® values were obtained from 50 volunteers 108 samples were collected during the early phase of clinical management from 48 severe trauma patients The blood was subject to EXTEM analysis and compared to the 95% tolerance limits from the volunteers Coagulopathy (was deemed to be present if EXTEM MCF was below 40mm, which is in the range indicating clinical concern defined by the ROTEM ® Expert Working Group Results The normal range data was broadly similar to ROTEM ® published data Admission samples were available from 31 battlefield casualties, and 39% of these were coagulopathic 51% of the samples from all 48 patients were coagulopathic (EXTEM MCF In addition, statistical comparison of clotting domains between normal volunteers and trauma patients suggests a difference in clot strengths due to a difference in platelet function rather than platelet number (mean 142×10 9 l −1 ) Conclusions The A10 value of ROTEM ® provides an early sensitive and specific assessment of coagulopathy after military trauma and may be of utility in guiding bespoke resuscitation We found some speculative evidence that in major trauma platelet function is particularly affected

The Preparation of Auxetic Foams by Three-Dimensional Printing and Their Characteristics

Abstract: Repeatable auxetic foams are produced using three-dimensional printing technologies. This methodology is applied here for the first time to produce playable polymeric auxetic foams with an idealized re-entrant cellular structure. During uniaxial tensile stress, the foams show negative Poisson's ratios as low as ?1.18. The experimental Poisson's ratios of the auxetic foams are compared against the data predicted by a three-dimensional mathematical model

Bacterial TIR-containing proteins and host innate immune system evasion.

Abstract: The innate immune system provides the first line of host defence against invading pathogens. Key to upregulation of the innate immune response are Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns (PAMPs) and trigger a signaling pathway culminating in the production of inflammatory mediators. Central to this TLR signaling pathway are heterotypic protein-protein interactions mediated through Toll/interleukin-1 receptor (TIR) domains found in both the cytoplasmic regions of TLRs and adaptor proteins. Pathogenic bacteria have developed a range of ingenuous strategies to evade the host immune mechanisms. Recent work has identified a potentially novel evasion mechanism involving bacterial TIR domain proteins. Such domains have been identified in a wide range of pathogenic bacteria, and there is evidence to suggest that they interfere directly with the TLR signaling pathway and thus inhibit the activation of NF-κB. The individual TIR domains from the pathogenic bacteria Salmonella enterica serovar Enteritidis, Brucella sp, uropathogenic E. coli and Yersinia pestis have been analyzed in detail. The individual bacterial TIR domains from these pathogenic bacteria seem to differ in their modes of action and their roles in virulence. Here, we review the current state of knowledge on the possible roles and mechanisms of action of the bacterial TIR domains.

The use of colorimetric sensor arrays to discriminate between pathogenic bacteria.

Abstract: A colorimetric sensor array is a high-dimensional chemical sensor that is cheap, compact, disposable, robust, and easy to operate, making it a good candidate technology to detect pathogenic bacteria, especially potential bioterrorism agents like Yersinia pestis and Bacillus anthracis which feature on the Center for Disease Control and Prevention’s list of potential biothreats. Here, a colorimetric sensor array was used to continuously monitor the volatile metabolites released by bacteria in solid media culture in an Advisory Committee on Dangerous Pathogen Containment Level 3 laboratory. At inoculum concentrations as low as 8 colony-forming units per plate, 4 different bacterial species were identified with 100% accuracy using logistic regression to classify the kinetic profile of sensor responses to culture headspace gas. The sensor array was able to further discriminate between different strains of the same species, including 5 strains of Yersinia pestis and Bacillus anthracis. These preliminary results suggest that disposable colorimetric sensor arrays can be an effective, low-cost tool to identify pathogenic bacteria.

Protecting against plague: towards a next-generation vaccine

Abstract: The causative organism of plague is the bacterium Yersinia pestis. Advances in understanding the complex pathogenesis of plague infection have led to the identification of the F1- and V-antigens as key components of a next-generation vaccine for plague, which have the potential to be effective against all forms of the disease. Here we review the roles of F1- and V-antigens in the context of the range of virulence mechanisms deployed by Y. pestis, in order to develop a greater understanding of the protective immune responses required to protect against plague.

Femtosecond-laser pumped CdSiP₂ optical parametric oscillator producing 100 MHz pulses centered at 6.2 μm.

Abstract: We report the first, to the best of our knowledge, femtosecond-laser-pumped optical parametric oscillator (OPO) based on the newly developed nonlinear crystal, CdSiP2. The OPO was synchronously pumped by a mode-locked Yb:KYW/Yb:fiber master-oscillator power amplifier, providing 1.053 μm pump pulses with durations of 130 fs at a repetition rate of 100 MHz. The 0.5-mm-thick CdSiP2 crystal was cut for a type-I noncritical interaction, providing a broad phase-matching bandwidth and ensuring excellent temporal overlap among the pump, signal, and idler pulses. The OPO generated signal pulses with a spectral coverage over 1260–1310 nm and mid-infrared idler pulses with a broad spectral coverage at 5.8–6.6 μm (6.2 THz). With a 2% output coupler (OC), the threshold pump power was 600 mW. At the maximum pump power of 1.6 W, 0.55 W was absorbed due to two-photon absorption and residual linear absorption in the CdSiP2 crystal, 0.75 W was transmitted, and 53 mW signal power was extracted through the OC. We estimate that the generated idler power was 24 mW.

Proteomic analysis of Bacillus subtilis strains engineered for improved production of heterologous proteins.

Abstract: The use of bacterial systems for recombinant protein production has advantages of simplicity, time and cost over competing systems However, widely used bacterial expression systems (eg Escherichia coli, Pseudomonas fluorescens) are not able to secrete soluble proteins directly into the culture medium This limits yields and increases downstream processing time and costs In contrast, Bacillus spp secrete native enzymes directly into the culture medium at grams-per-litre quantities, although the yields of some recombinant proteins are severely limited We have engineered the Bacillus subtilis genome to generate novel strains with precise deletions in the genes encoding ten extracytoplasmic proteases that affect recombinant protein secretion, which lack chromosomal antibiotic resistance genes The deletion sites and presence of single nucleotide polymorphisms were confirmed by sequencing The strains are stable and were used in industrial-scale fermenters for the production of the Bacillus anthracis vaccine protein, protective antigen, the productivity of which is extremely low in the unmodified strain We also show that the deletion of so-called quality control proteases appears to influence cell-wall synthesis, resulting in the induction of the cell-wall stress regulon that encodes another quality control protease

New Method To Predict the Thermal Degradation Behavior of Polybenzoxazines from Empirical Data Using Structure Property Relationships

Abstract: The degradation behavior of five polybenzoxazines is studied and the effect of selected experimental parameters (particle size, heating rate, and atmosphere) on the nature of the degradation pathway is examined. The particle size within the samples (systematically varied in four discrete size ranges: 250 μm) influences the progress of the early stage in the degradation mechanism (the cleavage of the bridging groups) such that the smaller particles are less stable, but the latter stages of the degradation mechanism remain largely unaffected. In contrast, the change in heating rate (5, 10, 15, 20 K min–1) of the thermogravimetric analysis has little effect on the first step in the degradation mechanism, but has a strong influence on the progress of the ring breakdown mechanism. Molecular simulation is shown to reproduce the thermo-mechanical behavior of the polybenzoxazine of bisphenol A/aniline very well, with the nuances of the glass transition and degradation onset temperatures s...

Protection against experimental melioidosis following immunization with live Burkholderia thailandensis expressing a manno-heptose capsule.

Abstract: Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei. It is highly resistant to antibiotic treatment, and there is currently no licensed vaccine. Burkholderia thailandensis is a close relative of Burkholderia pseudomallei but is essentially avirulent in mammals. In this report, we detail the protective efficacy of immunization with live B. thailandensis E555, a strain which has been shown to express an antigenic capsule similar to that of B. pseudomallei. Immunization with E555 induced significant protection against a lethal intraperitoneal B. pseudomallei challenge in a mouse model of infection, with no mice succumbing to infection over the course of the study, even with challenges of up to 6,000 median lethal doses. By comparison, mice immunized with B. thailandensis not expressing a B. pseudomallei-like capsule had significantly decreased levels of protection. E555-immunized mice had significantly higher levels of IgG than mice immunized with noncapsulated B. thailandensis, and these antibody responses were primarily directed against the capsule.

The development and introduction of ballistic protection of the external genitalia and perineum.

Abstract: In response to an Urgent Operational Requirement, the UK Ministry of Defence (MoD) investigated, designed, developed, trialled and subsequently fielded a Tiered Pelvic Protection System to service personnel deployed on Operation HERRICK in Afghanistan. An Urgent Statement of User Requirement (USUR) was drafted in order to equip service personnel with protection for the groin, perineum, buttocks and upper thigh areas from the effects of buried Improvised Explosive Devices (IEDs). Injuries to the groin and pelvic area from buried IEDs can have severe physiological and psychological impact; therefore the aim of the pelvic protection was to reduce the number and severity of such injuries and to improve the outcome, both in terms of quality of life of the survivors and increase the chances of survival. The aim of this paper is to outline some of the research and development that contributed to the design(s) of the Tiered Pelvic Protection System; describe the components of, and report the medical success of, the Tiered Pelvic Protection System.

Life under flow: A novel microfluidic device for the assessment of anti-biofilm technologies

Abstract: In the current study, we have developed and fabricated a novel lab-on-a-chip device for the investigation of biofilm responses, such as attachment kinetics and initial biofilm formation, to different hydrodynamic conditions. The microfluidic flow channels are designed using computational fluid dynamic simulations so as to have a pre-defined, homogeneous wall shear stress in the channels, ranging from 0.03 to 4.30 Pa, which are relevant to in-service conditions on a ship hull, as well as other man-made marine platforms. Temporal variations of biofilm formation in the microfluidic device were assessed using time-lapse microscopy, nucleic acid staining, and confocal laser scanning microscopy (CLSM). Differences in attachment kinetics were observed with increasing shear stress, i.e., with increasing shear stress there appeared to be a delay in bacterial attachment, i.e., at 55, 120, 150, and 155 min for 0.03, 0.60, 2.15, and 4.30 Pa, respectively. CLSM confirmed marked variations in colony architecture, i.e.,: (i) lower shear stresses resulted in biofilms with distinctive morphologies mainly characterised by mushroom-like structures, interstitial channels, and internal voids, and (ii) for the higher shear stresses compact clusters with large interspaces between them were formed. The key advantage of the developed microfluidic device is the combination of three architectural features in one device, i.e., an open-system design, channel replication, and multiple fully developed shear stresses.

Detection of the organophosphorus nerve agent VX and its hydrolysis products in white mustard plants grown in contaminated soil

Abstract: The Chemical Weapons Convention (CWC) aims to prohibit the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons by States Parties. Verification of compliance or investigations into allegations of use requires accurate detection of chemical warfare agents (CWAs) and their breakdown products. Detection of CWAs such as organophosphorus nerve agents in the environment relies mainly upon the analysis of soil. Here we present a novel method for the detection of the nerve agent VX and its hydrolysis products through analysis using a combination of gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) of ethanol extracts of contaminated vegetation (white mustard, Sinapis alba), which localised the compounds of interest, and in this study retained them in an extractable form longer than the soil.

Increasing the Potency of an Alhydrogel-Formulated Anthrax Vaccine by Minimizing Antigen-Adjuvant Interactions

Abstract: Aluminum salts are the most widely used vaccine adjuvants, and phosphate is known to modulate antigen-adjuvant interactions. Here we report an unexpected role for phosphate buffer in an anthrax vaccine (SparVax) containing recombinant protective antigen (rPA) and aluminum oxyhydroxide (AlOH) adjuvant (Alhydrogel). Phosphate ions bind to AlOH to produce an aluminum phosphate surface with a reduced rPA adsorption coefficient and binding capacity. However, these effects continued to increase as the free phosphate concentration increased, and the binding of rPA changed from endothermic to exothermic. Crucially, phosphate restored the thermostability of bound rPA so that it resembled the soluble form, even though it remained tightly bound to the surface. Batches of vaccine with either 0.25 mM (subsaturated) or 4 mM (saturated) phosphate were tested in a disease model at batch release, which showed that the latter was significantly more potent. Both formulations retained their potency for 3 years. The strongest aluminum adjuvant effects are thus likely to be via weakly attached or easily released native-state antigen proteins.

Fibrin Facilitates Both Innate and T Cell–Mediated Defense against Yersinia pestis

Abstract: The Gram-negative bacterium Yersinia pestis causes plague, a rapidly progressing and often fatal disease. The formation of fibrin at sites of Y. pestis infection supports innate host defense against plague, perhaps by providing a nondiffusible spatial cue that promotes the accumulation of inflammatory cells expressing fibrin-binding integrins. This report demonstrates that fibrin is an essential component of T cell–mediated defense against plague but can be dispensable for Ab-mediated defense. Genetic or pharmacologic depletion of fibrin abrogated innate and T cell–mediated defense in mice challenged intranasally with Y. pestis . The fibrin-deficient mice displayed reduced survival, increased bacterial burden, and exacerbated hemorrhagic pathology. They also showed fewer neutrophils within infected lung tissue and reduced neutrophil viability at sites of liver infection. Depletion of neutrophils from wild-type mice weakened T cell–mediated defense against plague. The data suggest that T cells combat plague in conjunction with neutrophils, which require help from fibrin to withstand Y. pestis encounters and effectively clear bacteria.

Identification of a Predicted Trimeric Autotransporter Adhesin Required for Biofilm Formation of Burkholderia pseudomallei

Abstract: The autotransporters are a large and diverse family of bacterial secreted and outer membrane proteins, which are present in many Gram-negative bacterial pathogens and play a role in numerous environmental and virulence-associated interactions. As part of a larger systematic study on the autotransporters of Burkholderia pseudomallei, the causative agent of the severe tropical disease melioidosis, we have constructed an insertion mutant in the bpss1439 gene encoding an unstudied predicted trimeric autotransporter adhesin. The bpss1439 mutant demonstrated a significant reduction in biofilm formation at 48 hours in comparison to its parent 10276 wild-type strain. This phenotype was complemented to wild-type levels by the introduction of a full-length copy of the bpss1439 gene in trans. Examination of the wild-type and bpss1439 mutant strains under biofilm-inducing conditions by microscopy after 48 hours confirmed that the bpss1439 mutant produced less biofilm compared to wild-type. Additionally, it was observed that this phenotype was due to low levels of bacterial adhesion to the abiotic surface as well as reduced microcolony formation. In a murine melioidosis model, the bpss1439 mutant strain demonstrated a moderate attenuation for virulence compared to the wild-type strain. This attenuation was abrogated by in trans complementation, suggesting that bpss1439 plays a subtle role in the pathogenesis of B. pseudomallei. Taken together, these studies indicate that BPSS1439 is a novel predicted autotransporter involved in biofilm formation of B. pseudomallei; hence, this factor was named BbfA, Burkholderia biofilm factor A.

Optically activated shutter using a photo-tunable short-pitch chiral nematic liquid crystal

Abstract: We report the demonstration of an optically activated shutter based upon a short-pitch chiral nematic liquid crystal (LC) device sandwiched between crossed polarizers. This LC is comprised of photo-active chiral dopants. In the trans-state, the LC appears dark between crossed polarizers due to the very short pitch. As the pitch is extended through exposure to ultraviolet light, the device becomes transmissive reaching a maximum for a particular value of the pitch. As a result, it is possible to switch between the light and dark states by subjecting the device to visible light so as to cause a cis-trans photo-isomerisation.

Allies at War: British and US Army Command Culture in the Italian Campaign, 1943–1944

Abstract: This article compares the philosophy and practice of command in the British and US Armies during the Italian Campaign of 1943–44. It assesses pre-war influences on the command approach adopted by each army, and shows how refinements derived from wartime experience enabled British and American commanders to successfully utilise mission command principles to outfight the German Army in the latter years of World War II. This examination directly challenges the historical consensus that Allied commanders were disadvantaged by an inability to exploit the advantages of mission command, and that the German Army retained superior command practices, despite its other failings, throughout the fighting between 1939 and 1945. These conclusions hold additional relevance to modern military organisations which have emphasised mission command as the optimal solution to effective command in battle since the 1980s, but from an inaccurate understanding of German, British and American command traditions and experien...

Weighted space-filling designs

Abstract: Many computer models or simulators have probabilistic dependencies between their input variables, which if not accounted for during design selection may result in a large numbers of simulator runs being required for analysis. We propose a method that incorporates known dependencies between input variables into design selection for simulators and demonstrate the benefits of this approach via a simulator for atmospheric dispersion. We quantify the benefit of the new techniques over standard space-filling and Monte Carlo simulation. The proposed methods are adaptations of computer-generated spread and coverage space-filling designs, with ‘distance’ between two input points redefined to include a weight function. This weight function reflects any known multivariate dependencies between input variables and prior information on the design region. The methods can include quantitative and qualitative variables, and different types of prior information. Novel graphical methods, adapted from fraction of design space plots, are used to assess and compare the designs.

Modelling for conflict: the legacy of ballistic research and current extremity in vivo modelling

Abstract: Extremity ballistic injury is unique and the literature intended to guide its management is commonly misinterpreted. In order to care for those injured in conflict and conduct appropriate research, clinicians must be able to identify key in vivo studies, understand their weaknesses and desist the propagation of miscited and misunderstood ballistic dogma. This review provides the only inclusive critical overview of key studies of relevance to military extremity injury. In addition, the non-ballistic studies of limb injury, stabilisation and contamination that will form the basis from which future small animal extremity studies are constructed are presented. With an awareness of the legacy of military wound models and an insight into available generic models of extremity injury and contamination, research teams are well placed to optimise future military extremity injury management.

Temporal changes in ROTEM®-measured coagulability of citrated blood samples from coagulopathic trauma patients

Abstract: Background: Rotational thromboelastometry (ROTEM (R)) relies on citrated blood samples, which are regarded as biologically stable for up to 4 h after venepuncture. However, this recommendation is based on data from normal volunteers. The aim of this study was to evaluate possible temporal changes in the coagulability of blood samples from coagulopathic trauma patients.Patients and methods: This is a prospective series of 10 coagulopathic (maximum clot firmness, MCF < 40 mm) trauma patients. ROTEM (R) EXTEM (tissue factor activated) and FIBTEM (tissue factor activated, cytochalasin D inhibited) analyses were performed on samples obtained on admission, and after approximately 60 min of storage in an incubator, at 37 degrees C.Results: There were statistically significant differences between the median EXTEM MCF (22 mm vs 54 mm, p < 0.001) and alpha angle (30.5 vs 59.5 degrees, p = 0.004) of the analyses performed immediately after sampling, and 51 min (median) subsequently, but not coagulation time (CT, p = 0.133), clot formation time (p = 0.0625) or maximum lysis (ML, p = 0.154). There were also no differences in median FIBTEM MCF (p = 1.00) or CT (p = 0.877) between the immediate and delayed analyses.Conclusions: Repeated ROTEM (R) EXTEM analysis of citrated samples from coagulopathic trauma patients shows a spontaneous improvement in coagulability with time. The absence of parallel changes on FIBTEM analysis suggests that this effect may be due to a change in platelet function. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.

Soil biotransformation of thiodiglycol, the hydrolysis product of mustard gas: understanding the factors governing remediation of mustard gas contaminated soil

Abstract: Thiodiglycol (TDG) is both the precursor for chemical synthesis of mustard gas and the product of mustard gas hydrolysis. TDG can also react with intermediates of mustard gas degradation to form more toxic and/or persistent aggregates, or reverse the pathway of mustard gas degradation. The persistence of TDG have been observed in soils and in the groundwater at sites contaminated by mustard gas 60 years ago. The biotransformation of TDG has been demonstrated in three soils not previously exposed to the chemical. TDG biotransformation occurred via the oxidative pathway with an optimum rate at pH 8.25. In contrast with bacteria isolated from historically contaminated soil, which could degrade TDG individually, a consortium of three bacterial strains isolated from the soil never contaminated by mustard gas was able to grow on TDG in minimal medium and in hydrolysate derived from an historical mustard gas bomb. Exposure to TDG had little impacts on the soil microbial physiology or on community structure. Therefore, the persistency of TDG in soils historically contaminated by mustard gas might be attributed to the toxicity of mustard gas to microorganisms and the impact to soil chemistry during the hydrolysis. TDG biodegradation may form part of a remediation strategy for mustard gas contaminated sites, and may be enhanced by pH adjustment and aeration.

Inhibition of Yersinia pestis DNA adenine methyltransferase in vitro by a stibonic acid compound: identification of a potential novel class of antimicrobial agents

Abstract: Background and Purpose Multiple antibiotic resistant strains of plague are emerging, driving a need for the development of novel antibiotics effective against Yersinia pestis. DNA adenine methylation regulates numerous fundamental processes in bacteria and alteration of DNA adenine methlytransferase (Dam) expression is attenuating for several pathogens, including Y. pestis. The lack of a functionally similar enzyme in humans makes Dam a suitable target for development of novel therapeutics for plague. Experimental Approach Compounds were evaluated for their ability to inhibit Dam activity in a high-throughput screening assay. DNA was isolated from Yersinia grown in the presence of lead compounds and restricted to determine the effect of inhibitors on DNA methylation. Transcriptional analysis was undertaken to determine the effect of an active inhibitor on virulence-associated phenotypes. Key Results We have identified a series of aryl stibonic acids which inhibit Dam in vitro. The most active, 4-stibonobenzenesulfonic acid, exhibited a competitive mode of inhibition with respect to DNA and a Ki of 6.46 nM. One compound was found to inhibit DNA methylation in cultured Y. pestis. The effects of this inhibition on the physiology of the cell were widespread, and included altered expression of known virulence traits, including iron acquisition and Type III secretion. Conclusions and Implications We have identified a novel class of potent Dam inhibitors. Treatment of bacterial cell cultures with these inhibitors resulted in a decrease in DNA methylation. Expression of virulence factors was affected, suggesting these inhibitors may attenuate bacterial infectivity and function as antibiotics.

Investigating the use of protein saver cards for storage and subsequent detection of bovine anti-Brucella abortus smooth lipopolysaccharide antibodies and gamma interferon.

Abstract: Brucella abortus, a smooth strain of the genus Brucella, is the causative agent of bovine brucellosis. To support the ongoing development of diagnostic tests for bovine brucellosis, the use of Protein Saver cards (Whatman) for bovine blood serum and plasma sample collection has been evaluated. These cards offer significant logistical and safety alternatives to transporting and storing liquid samples and may aid in diagnostic programs and validation studies. To evaluate the utility of these cards, 204 bovine blood serum samples from Brucella-infected and noninfected animals were stored on and eluted from the Protein Saver cards. Anti-Brucella smooth lipopolysaccharide (sLPS) antibody titers for the serum eluates were compared to those of the unprocessed original serum samples by indirect enzyme-linked immunosorbent assay (ELISA). The results showed a highly significant correlation between titers from the serum eluates and the unprocessed sera. Therefore, under these circumstances, serum eluates and unprocessed serum samples may be used interchangeably. Blood plasma from 113 mitogen-stimulated whole-blood samples was added to and eluted from the Protein Saver cards. The gamma interferon (IFN-γ) titers in the plasma eluates were compared to those of the unprocessed plasma samples obtained by IFN-γ ELISA. The results showed a significant correlation between the plasma eluates and the unprocessed plasma samples. To derive a signal in the plasma eluate, it was necessary to develop a novel and highly sensitive ELISA for the detection of IFN-γ. The serum samples stored on cards at room temperature over a 10-day period showed little variation in antibody titers. However, the plasma eluates showed a progressive loss of IFN-γ recovery over 10 days when stored at room temperature.

An integrated approach towards future ballistic neck protection materials selection.

Abstract: Ballistic protection for the neck has historically taken the form of collars attached to the ballistic vest (removable or fixed), but other approaches, including the development of prototypes incorporating ballistic material into the collar of an under body armour shirt, are now being investigated. Current neck collars incorporate the same ballistic protective fabrics as the soft armour of the remaining vest, reflecting how ballistic protective performance alone has historically been perceived as the most important property for neck protection. However, the neck has fundamental differences from the thorax in terms of anatomical vulnerability, flexibility and equipment integration, necessitating a separate solution from the thorax in terms of optimal materials selection. An integrated approach towards the selection of the most appropriate combination of materials to be used for each of the two potential designs of future neck protection has been developed. This approach requires evaluation of the propertie...