Purpose: Osteoarthritis (OA) is a common debilitating joint disease effecting many of the world's elderly population. There are no known treatments for OA, only symptom management. Identifying and understanding the role of early indicators of OA is needed to aid the development of effective treatment solutions. Through gene editing technology (CRISPR/Cas9) the role of genes of interest can be elucidated through targeted editing and subsequent experimental investigation in relevant cell models. The cytokine Interleukin-16 (IL-16) has been identified to be present in increasing amounts in osteoarthritic cartilage.

Purpose: Osteoarthritis as a degenerative joint disease severely impacts the elderly population. Despite being a common condition affecting people worldwide, stages of early disease development are not yet fully understood. Additionally, no disease-modifying treatments are available with symptom management the primary approach. A need to find and investigate novel early indicators of the disease and to develop a treatment to target OA at this stage is required in order to increase understanding of disease development and for designing effective treatments.

Purpose: Synovial inflammation has been shown to play an important role in the pathogenesis and development of osteoarthritis (OA), primarily through the production of pro-inflammatory mediators by infiltrating inflammatory cell populations. To optimise potential cell therapies for the treatment of OA, there is a need to understand the involvement and thereby the nature of the inflammatory environment during development of OA. The aim of this study is to define the initial immune response to injections required for development of collagenase induced osteoarthritis (CIOA) and the changes in local and systemic immune cell phenotype and overall inflammatory milieu that occur over the development of OA. Methods: CIOA was generated in C57BL/6 mice via intraarticular injections of Collagenase VII into knee joints. Three animals underwent CIOA treatment and three animals received saline intraarticular injections (Sham group) per treatment group. At selected time points (Day 0, 7, 14, 21, 28, 49 and 56) animals were euthanized and processed for analysis. Popliteal lymph nodes (PLN), inguinal lymph nodes (ILN) and spleen were harvested, from which single cell suspensions were generated and analysed for T-cell and Macrophage marker expression using a FACS Canto cytometer. Synovial fluid samples were harvested simultaneously and their cytokine profiles were subsequently analysed using a multiplex platform, assessing 23 different cytokines over the time course. Results: Increased levels of MHC-II+/CD11b+ macrophages with respect to both percentage and expression were observed in CIOA versus Sham early in ILN (D14) and later in Spleen (D28 and D49). A late (D49) increase in MHC-I+/CD11b+ macrophages was observed in Spleen, however no difference was observed between CIOA and Sham in ILN with regards to MHC-I+/CD11b+ percentage or expression. A large increase in both the percentage of CD86+/CD11b+ cells and expression was demonstrated in late OA (D56) in ILN, with an earlier increase evident in Spleen (D21). With regards to changes in T cell populations during OA initiation and development no change was noted in the CD4+/CD3+ or CD8+/CD3+ populations in CIOA compared to Sham. However, activation of these cells as measured by percentage of CD25+ and CD69+ cells within these populations showed variations between the groups. The percentage of CD25+CD4+/CD3+ cells increased early (D14) in ILN and late (D56) in Spleen in CIOA compared to Sham while the percentage of CD25+CD8+/CD3+ cells in Spleen increased in late OA (D49). In addition, the CIOA animals had higher numbers of CD69+ cells in both T cell populations versus the Sham group. Conclusions: The results indicate an early local immune response to CIOA followed by a later systemic response. Apparent coordinated increases in MHC-II and CD25+/CD4+/CD3+ cells in early OA suggest interplay of these cells. Similarly, the later appearance of MHC-I+ cells in conjunction with increased CD25+/CD8+/CD3+ cells could signify potential CD8+ T cell activation subsequent to activation of CD4+ T cells. The activation status of these cells is further validated by the observed coordinated increase in the percentage of CD69+ cells in both CD4+ and CD8+ populations in tandem with the increases in the percentage of CD25+ cells. In combination with increased CD86, our data indicates the establishment of a pro-inflammatory state during the course of OA development and progression. This data provides valuable insight into the inflammatory status in OA, which should be used to inform future studies investigating the use of cellular therapies for the treatment of OA. Potential therapies should possess immunosuppressive capabilities sufficient to combat the now established OA environment of proliferating and activated immune cell populations. Further potential applications include exploitation of this data for licensing of cells for enhanced therapeutic efficacy, in addition to more informed strategies for optimal timing of cell therapy administration.

Introduction: The successful introduction of endovascular interventions for iliac occlusive disease has led to a reduction in the number of iliac endarerectomies being performed. However for a select cohort of patients, eversion endarterectomy remains as the established surgical treatment of choice. Methods: A retrospective review of patients in a single centre who underwent external iliac eversion endarterectomy between 2000 and 2017. Results: 35 patients underwent eversion iliac endarterectomy. The mean age was 66 (range 46–82) and the modal American society of anesthesiologists (ASA) grade was 3. The indications for the procedure were life affecting claudication (n=17) and critical limb ischemia (n = 19). 10 had adjunctive procedures. The mean follow up was 35 months (range 1–132). The cumulative patency 12 months post procedure was 82.1%. 7 patients required some form of secondary reintervention. Conclusion: Eversion iliac endarterectomy remains a successful alternative of treating occlusive iliac disease offering impressive patency outcomes and should still be considered in select patients.

Background: EVAR has emerged as an alternative to open AAA repair in recent times, bringing with it new diagnostic and therapeutic challenges, including the need for lifelong surveillance. Traditionally, CTA has been the gold-standard for the first post-operative scan following EVAR. However, this entails risk exposure including contrast nephropathy and radiation. Several studies have looked into CDU as an alternative tool for EVAR surveillance, with conflicting results. Aims: To examine post-operative CDU results and compare them with CTA results, used as the gold-standard. Methods: All patients who underwent an EVAR for infrarenal AAA at our institution between 2003 and 2017, and had a CTA and CDU within 30 days of the procedure were included in our analysis. Results: There was perfect correlation between CTA and CDU when examining sac size and the presence or absence of endoleak, with a good correlation when looking at the type of endoleak. Conclusion: CDU is a safe and effective post-operative EVAR surveillance tool when carried out by experienced operators in an appropriate patient population.

There is accumulating evidence that long-term disability and disease progression in multiple sclerosis (MS) are due to prolonged sodium channel opening along demyelinated axons. Despite good evidence in animal models of MS that partial voltage-gated sodium channel (VGSC) blockade reduces disease progression, little is known about its effects in patients, despite widespread use of such agents in the symptomatic management of MS.

To evaluate blood gases and ventilatory parameters before and after two doses of surfactant in premature infants with respiratory decompensation after recovery from primary respiratory distress syndrome (RDS). This prospective pilot study enrolled infant's ⩾500 g birth weight, from 7 days to 3 months of age, with a secondary respiratory decompensation lasting at least 4 h prior to study entry. Infants received two doses of surfactant, 12 h apart. A total of 20 neonates qualified for secondary surfactant administration. PCO2 (P<0.001); pH (P<0.001); mean airway pressure (P<0.05); FiO2 (P<0.05); modified ventilatory indices (P<0.004) and respiratory severity scores (P<0.001) improved significantly at both 12 and 24 h after surfactant administration. Secondary surfactant administration may be effective in reducing short-term ventilatory requirements in neonates who have a respiratory decompensation after recovery from initial RDS. Randomized controlled trials are needed to confirm these preliminary findings.

New flavoproteins photogenerate singlet oxygen, enabling genetically encoded correlative light and electron microscopy. Synthetic peptides provide an amplifying mechanism for targeting fluorophores, MRI contrast agents, and drugs to sites of protease activity (e.g. tumors) in vivo.

Chlamydiae are gram-negative obligate intracellular pathogens to which access to an intracellular environment is paramount to their survival and replication. To this end, chlamydiae have evolved extremely efficient means of invading nonphagocytic cells. To elucidate the host cell machinery utilized by Chlamydia trachomatis in invasion, we examined the roles of the Rho GTPase family members in the internalization of chlamydial elementary bodies. Upon binding of elementary bodies on the cell surface, actin is rapidly recruited to the sites of internalization. Members of the Rho GTPase family are frequently involved in localized recruitment of actin. Clostridial Toxin B, which is a known enzymatic inhibitor of Rac, Cdc42 and Rho GTPases, significantly reduced chlamydial invasion of HeLa cells. Expression of dominant negative constructs in HeLa cells revealed that chlamydial uptake was dependent on Rac, but not on Cdc42 or RhoA. Rac but not Cdc42 was found to be activated by chlamydial attachment. The effect of dominant negative Rac expression on chlamydial uptake is manifested through the inhibition of actin recruitment to the sites of chlamydial entry. Studies utilizing Green Fluorescent Protein fusion constructs of Rac, Cdc42 and RhoA, showed Rac to be the sole member of the Rho GTPase family recruited to the site of chlamydial entry.

The chlamydial developmental cycle is characterized by an intracellular replicative form, termed the reticulate body, and an extracellular form called the elementary body. Elementary bodies are characterized by a condensed chromatin, which is maintained by a histone H1-like protein, Hc1. Differentiation of elementary bodies to reticulate bodies is accompanied by dispersal of the chromatin as chlamydiae become transcriptionally active, although the mechanisms of Hc1 release from DNA have remained unknown. Dissociation of the nucleoid requires chlamydial transcription and translation with negligible loss of Hc1. A genetic screen was therefore designed to identify chlamydial genes rescuing Escherichia coli from the lethal effects of Hc1 overexpression. CT804, a gene homologous to ispE, which encodes an intermediate enzyme of the non-mevalonate methylerythritol phosphate (MEP) pathway of isoprenoid biosynthesis, was selected. E. coli coexpressing CT804 and Hc1 grew normally, although they expressed Hc1 to a level equivalent to that which condensed the chromatin of parent Hc1-expressing controls. Inhibition of the MEP pathway with fosmidomycin abolished IspE rescue of Hc1-expressing E. coli. Deproteinated extract from IspE-expressing bacteria caused dispersal of purified chlamydial nucleoids, suggesting that chlamydial histone-DNA interactions are disrupted by a small metabolite within the MEP pathway rather than by direct action of IspE. By partial reconstruction of the MEP pathway, we determined that 2-C-methylerythritol 2,4-cyclodiphosphate dissociated Hc1 from chlamydial chromatin. These results suggest that chlamydial histone-DNA interactions are disrupted upon germination by a small metabolite in the MEP pathway of isoprenoid biosynthesis.