The effects of crossbow impacts onto a common automotive vehicle side window-a preliminary study.

In recent times, the number of criminal incidents involving crossbows in the UK has increased with many incidents resulting in either injuries or fatalities. Whilst the effects of crossbow bolts on the body are well understood, there is a limited understanding on how these projectiles interact with the wider environment. One area of particular interest is the interaction between common vehicle side windows and bolts. In this study, the penetrability of two distinct bolts using an off-the-shelve crossbow against a common automotive side window was explored, where velocity loss up to 25 m/s post impact was recorded. All windows failed through radial glass fracture at a rate up to 1600 m/s, whilst bolt damage varied from tip holder decoupling, shaft damage, and traumatic fletching removal. No distinct relationship between bolt type, velocity, and window damage was identified.

Does using the WHO surgical checklist improve compliance to venous thromboembolism prophylaxis guidelines?

BACKGROUND: Using the World Health Organisation (WHO) surgical checklist has been shown to improve the safety of patients undergoing surgery. Its effect on the compliance to venous thromboembolism (VTE) guidelines has not been established before. Our objective was to assess if using the WHO checklist improved compliance to VTE prophylaxis guidelines. METHODS: Compliance to NICE VTE guidelines were prospectively assessed in all general surgery patients over two separate audit periods, before and after 6 months of the routine use of the WHO checklist. Correct completion of the checklist was verified. RESULTS: 370 patients (173 [47%] male, 197 [53%] female, mean age 61.6 yrs). Non compliance to NICE VTE guidelines was reduced form 16/233 (6.9%) to 3/137 (2.1%) after introduction of the checklist (p = 0.046 Fisher exact test). Non compliance was reduced in both emergency and elective procedures. CONCLUSIONS: Establishment of the WHO checklist for routine use in all general surgery patients may significantly improve VTE guideline compliance of all general surgery patients.

Testing the blast response of foam inserts for helmets.

Modern era combat helmets have different iterations and configurations to offer greater protection from blunt impact or ballistic penetration to suit the theatre of operation, although there are currently no standards for blast protection. Moreover, incorporation of blast protection into the same constrained mass-volume envelope is extremely challenging as there is very little space for a material to absorb or dissipate the shockwave. Foam padding is fitted in contemporary combat helmet designs for comfort and standoff purposes. Examples were subjected to blastwaves generated from an air-driven shocktube, along with open cell polyurethane foam specimens of varying pores per inch and thicknesses to. Whilst the range of samples tested did not afford any superior blast mitigation behaviour over the foam already present in helmets, they exhibited comparable performance with a lower mass. There also appears to be positive correlation between increased mass and increased impulse transmitted through the foam. The literature suggests that multiple mechanisms of damage for blast induced mild Traumatic Brain Injury (bTBI) can be caused by the helmet itself, therefore additional protection from a blunt or ballistic impact may increase the risk of damage from a blast insult.

Purification of functional lactotrophs and somatotrophs from female rats using fluorescence-activated cell sorting.

As the secretory granules of anterior pituitary cells fuse with the cell surface, there would appear to be sufficient hormone present on the cell surface to be labelled by polyclonal hormone antibodies and thus analysed by flow cytometry. We have therefore applied fluorescence-activated cell sorting to these labelled pituitary cells. Percentage purity and depletion of other cell types was assessed by immunocytochemistry and the reverse haemolytic plaque assay (RHPA). Results demonstrate that fluorescence-activated cell sorting allows almost complete purification of functional lactotrophs and somatotrophs to 96.7 +/- 1.7 (S.E.M.)% and 98 +/- 1.0% respectively by immunocytochemistry, and to 95.8 +/- 1.1% and 97 +/- 0.8% respectively by RHPA. Depletion of other anterior pituitary cell types to less than 2% was demonstrated by both immunocytochemistry and RHPA. Fluorescence-activated cell sorting to this degree of purity was routinely possible with cell yields of 91 +/- 3.4%. To obtain such purity/depletion, it was necessary to use specific antisera of high titre, at concentrations which ensured maximal cell-surface labelling associated with maximal stimulation of hormonal secretion by the appropriate hypothalamic stimulatory factor. Separating cells on the basis of the intensity of prolactin cell-surface labelling demonstrated a low level of binding of the prolactin antibody to gonadotrophs (but not of sufficient fluorescence intensity to be sorted into the prolactin enriched population), raising the possibility of prolactin receptors on gonadotrophs. We were unable to demonstrate the presence of mammosomatotrophs in the normal female rat, since purified lactotrophs did not contain or secrete GH nor did purified somatotrophs contain or secrete prolactin.

Flow cytometric analysis of functional anterior pituitary cells from female rats.

Laser-light scatter signals generated from living cells provide useful information with regard to both cell size (forward-angle light scatter) and granularity (ninety-degree or perpendicular light scatter). By measuring angles of light scatter and fluorescence, a fluorescence-activated cell sorter is capable of analysing and sorting cells on the basis of their size, granularity and cell-surface fluorescence. Using an electronically programmable individual cell sorter we were able to analyse single, viable, dispersed anterior pituitary cells of the female rat on the basis of their laser light scatter characteristics. Two distinct populations of differing granularity were defined: 26 +/- 2.2% (mean +/- S.E.M.) were more granular and 74 +/- 3.5% less granular. Acutely dispersed anterior pituitary cells were labelled with antibodies against four of the anterior pituitary hormones, and cell size and granularity were compared amongst the different hormonal cell types. Somatotrophs were the most granular cell type, gonadotrophs were the largest and corticotrophs the smallest, whilst lactotrophs were of intermediate size. Labelling was demonstrated to be dependent upon the secretory state of the cell. Hypothalamic stimulating factors increased cell-surface labelling, whilst dopamine and somatostatin decreased labelling. These changes compare favourably with published data obtained by immunocytochemistry. Using dual-colour fluorescence cell surface labelling we were unable to define a population of cells secreting both prolactin and growth hormone (mammosomatotrophs).

Does surgical volume affect outcome after primary and revision knee arthroplasty? A systematic review of the literature.

BACKGROUND: In 2009 there were 72,980 primary and 4565 revision knee arthroplasties performed in England and Wales [1]. Given the large number of procedures done annually any factors that may influence outcome and benefit the patient must be considered seriously. OBJECTIVES: To find out whether a relationship exists between hospital and surgical volume and patient outcomes for primary and revision knee arthroplasty. A systematic review of the literature was performed to evaluate the current evidence using the PRISMA criteria [2]. DATA SOURCES: A computerised literature search was performed on the electronic databases PubMed, Medline, Embase and CINAHL between 1973 and 2011. STUDY ELIGIBILITY CRITERIA: All abstracts, in the English language, pertaining to either surgical or hospital volume and outcome after primary and revision knee arthroplasty between 1973 and 2011 were considered. Outcomes of interest included morbidity, mortality, clinical and economic outcomes. CONCLUSIONS: Both the orthopaedic and surgical specialties literature demonstrates a clear and consistent relationship between both surgeon and hospital volume with outcome, higher volume being associated with improved patient outcomes. In view of the literature consideration should be given to whether all orthopaedic operations should be carried out by all surgeons in all hospitals.

Human foamy virus integrase fails to catalyse the integration of a circular DNA molecule containing an LTR junction sequence.

The presence of closed circular forms of the linear DNA genome of human foamy virus (HFV) has not been established. The ability of the HFV integrase (IN) to catalyse the integration of these circular forms (termed 2 long terminal repeat (LTR) circles) was investigated, with a view to producing a novel hybrid vector. To this end, a construct was made containing, in addition to the enhanced green fluorescent protein (eGFP) marker gene, the last 27 bp of the 3' U5 LTR region of HFV fused to the first 28 bp of the 5' U3 LTR, the latter representing a 2LTR circle. Marker gene expression following transfection of both 293 and 293T cells indicated that the level of integration was not significantly increased by the HFV IN. Moreover, correctly integrated provirus-like forms of the input plasmid could not be detected by PCR. Taken together, these results show that the HFV IN is not able to integrate a circular molecule containing an LTR junction and, hence, the technique is not exploitable as a tool to produce hybrid vectors for gene therapy.

Extraction procedures for atomic absorption spectrometric analysis of toxic metals in urban dust.

A comparison has been made of eight acid extraction systems prior to the atomic absorption analysis of lead, nickel, copper, cadmium, cobalt, chromium, zinc, arsenic and mercury in street dust samples. Statistical treatment of the results enabled a valid comparison to be made in terms of overall extraction efficiency. For the purposes of carrying out large scale environmental surveys it was found that extraction with dilute nitric acid was the most suitable method. Analysis of the extracts by atomic absorption spectroscopy was shown to permit the accumulation of reliable data with the minimum requirement of apparatus and time.

Potential therapeutic applications of recombinant, invasive E. coli.

An invasive Escherichia coli expressing the inv gene from Yersinia pseudotuberculosis was used as a vector for protein delivery to mammalian epithelial cells. Upon incubation with beta1-integrin-expressing mammalian cells, the bacteria are internalized, allowing bacteria-encoded proteins to function from within the mammalian cell. These bacteria are eventually processed in the host phagosome where they are destroyed. Expression of listeriolysin O from Listeria monocytogenes in the bacterium and its subsequent release into the phagosome triggers the breakdown of the membrane, allowing the release of the bacterial content into the cytosol of host cells. Using this vector, we demonstrate delivery of a gene and intact, functional proteins into mammalian cells in which beta1-integrin is expressed and accessible. At a ratio of bacteria/mammalian cells compatible with the survival of the mammalian cells, protein delivery can be observed in the entire cell population in vitro, while gene transfer is far less efficient. Protein delivery can also be achieved in vivo in mouse tumour models and can be detected at least 96 h after inoculation. Functional, natural E. coli proteins are delivered in the process and can provide therapeutic benefit in vivo, when associated with prodrugs. This therapeutic effect is associated with infiltration of neutrophils, eosinophils, macrophages and to a lesser extent dendritic cells in the tumour mass.