Rheumatoid arthritis sera react with a phage-displayed peptide selected by a monoclonal antibody to type II collagen that has homology to EBNA-1

Antibodies to type II collagen, and to Epstein Barr virus nuclear antigen-1 (EBNA-1) have been associated with rheumatoid arthritis (RA). In studies involving probing of phage-displayed random peptide libraries with an antibody to type II collagen, CII-C1, we observed that among 17 phagotopes selected 5 expressed peptides with homology with the sequence of EBNA-1. The residues in common were RLPFG. Hence we tested sera from 50 patients with RA, of whom 26 had antibodies to native type II collagen, and 43 healthy controls, for reactivity by ELISA with a phagotope selected 4 times, which expressed the peptide RRLPFGSQM. Eight RA sera (16%) but no normal sera reacted with the phagotope (p = 0.025). This reactivity could not be correlated with reactivity of RA sera with EBNA-1 by semi-quantitative western blot, with which reactivity occurred in 78% of RA patients and 81% of controls. Evidence for molecular mimicry was not found insofar as the phagotope did not inhibit reactivity of RA sera with EBNA-1 and CII-C1 was not reactive with EBNA-1. We conclude that the reactivity of the RA sera with the phagotope is most likely due to the phagotope being a mimic of an epitope of type II collagen for a proportion of RA sera.

Inhibition of myeloperoxidase- and neutrophil-mediated oxidant production by tetraethyl and tetramethyl nitroxides

The powerful oxidant HOCl (hypochlorous acid and its corresponding anion, −OCl) generated by the myeloperoxidase (MPO)–H2O2–Cl− system of activated leukocytes is strongly associated with multiple human inflammatory diseases; consequently there is considerable interest in inhibition of this enzyme. Nitroxides are established antioxidants of low toxicity that can attenuate oxidation in animal models, with this ascribed to superoxide dismutase or radical-scavenging activities. We have shown (M.D. Rees et al., Biochem. J. 421, 79–86, 2009) that nitroxides, including 4-amino-TEMPO (4-amino-2,2,6,6-tetramethylpiperidin-1-yloxyl radical), are potent inhibitors of HOCl formation by isolated MPO and activated neutrophils, with IC50 values of ~1 and ~6 µM respectively. The utility of tetramethyl-substituted nitroxides is, however, limited by their rapid reduction by biological reductants. The corresponding tetraethyl-substituted nitroxides have, however, been reported to be less susceptible to reduction. In this study we show that the tetraethyl species were reduced less rapidly than the tetramethyl species by both human plasma (89–99% decreased rate of reduction) and activated human neutrophils (62–75% decreased rate). The tetraethyl-substituted nitroxides retained their ability to inhibit HOCl production by MPO and activated neutrophils with IC50 values in the low-micromolar range; in some cases inhibition was enhanced compared to tetramethyl substitution. Nitroxides with rigid structures (fused oxaspiro rings) were, however, inactive. Overall, these data indicate that tetraethyl-substituted nitroxides are potent inhibitors of oxidant formation by MPO, with longer plasma and cellular half-lives compared to the tetramethyl species, potentially allowing lower doses to be employed.

Dissecting the prostate cancer stem cell niche inside the bone marrow

Prostate cancer frequently metastasizes to bone, which becomes incurable; yet how cancer cells manage to migrate and grow inside the bone remains unknown. In this study I have discovered that both bone and fat cells within the bone marrow actively promote the survival and expansion of prostate cancer cells, and have subsequently developed approaches that can effectively inhibit these processes. Therefore, my work offers opportunities for the development of new prognostic and therapeutic approaches against metastatic prostate cancer and have the potential for improving the treatment outcome of the patients.

Reinforcing stigma or delivering a fresh start: Bankruptcy and future engagement in the workforce

In Australia, bankruptcy retains a social stigma, as is often seen as a personal failing, and an indication that the individual cannot be trusted to meet their obligations. Official labelling and informal labelling reinforce this stigmatisation of bankruptcy in employment and business contexts. This occurs through legislation and policy that imposes restrictions on participation in some occupations on the grounds of bankruptcy, and imposes obligations on persons to disclose their bankruptcy to their employer. These restrictions and obligations that are varying in length and extent, both within industries and professions and across industries and professions, and appear to lack a coherent policy justification. Further, informal labelling is facilitated by the law providing for a permanent, publicly accessible record of bankruptcy, and failing to restrict the use of bankruptcy information in employment and business decision-making. This stigmatisation of bankruptcy inhibits the fresh start objective of bankruptcy, and is not supported by a strong correlation between bankruptcy and negative personal or other attributes. This article therefore argues that a review is needed to determine the circumstances in which there is a genuine policy justification for employment restrictions, and the appropriate length and scope of such restrictions. Reform of the Bankruptcy Act should also be considered. Possible areas for law reform including reducing the minimum period of bankruptcy; removing the permanency and/or public accessibility of the bankruptcy record; revising the language used in the Bankruptcy Act; and introducing a prohibition or restriction on the ability of employers to use bankruptcy status in employment decision making. Such changes would promote the fresh start objective of Australia’s bankruptcy system, and increase the likelihood that bankruptcy does not unfairly inhibit an individual’s ability to engage as an economic actor in Australian society and thereby improve their financial well-being.

Immunopathogenesis of ankylosing spondylitis

Ankylosing spondylitis is a model immunogenetic disease with major common and rare genetic risk factors, likely environmental contributors to its pathogenesis and, to date, no treatment that has been shown to induce disease remission in long-term studies. The discovery of the association of HLA-B27 with the disease in the early 1970s triggered extensive efforts to elucidate the mechanism of this association. However, the precise role of HLA-B27 in ankylosing spondylitis pathogenesis remains unclear. In recent years, rapid progress made in the discovery of non-MHC genes involved in susceptibility to ankylosing spondylitis has combined with increasing ability to investigate the immune system to make rapid progress in unraveling the etiopathogenesis of the condition. © 2013 Future Medicine Ltd.

Standardised antibacterial Manuka honey in the management of persistent post-operative corneal oedema: A case series

Background Corneal oedema is a common post-operative problem that delays or prevents visual recovery from ocular surgery. Honey is a supersaturated solution of sugars with an acidic pH, high osmolarity and low water content. These characteristics inhibit the growth of micro-organisms, reduce oedema and promote epithelialisation. This clinical case series describes the use of a regulatory approved Leptospermum species honey ophthalmic product, in the management of post-operative corneal oedema and bullous keratopathy. Methods A retrospective review of 18 consecutive cases (30 eyes) with corneal oedema persisting beyond one month after single or multiple ocular surgical procedures (phacoemulsification cataract surgery and additional procedures) treated with Optimel Antibacterial Manuka Eye Drops twice to three times daily as an adjunctive therapy to conventional topical management with corticosteroid, aqueous suppressants, hypertonic sodium chloride five per cent, eyelid hygiene and artificial tears. Visual acuity and central corneal thickness were measured before and at the conclusion of Optimel treatment. Results A temporary reduction in corneal epithelial oedema lasting up to several hours was observed after the initial Optimel instillation and was associated with a reduction in central corneal thickness, resolution of epithelial microcysts, collapse of epithelial bullae, improved corneal clarity, improved visualisation of the intraocular structures and improved visual acuity. Additionally, with chronic use, reduction in punctate epitheliopathy, reduction in central corneal thickness and improvement in visual acuity were achieved. Temporary stinging after Optimel instillation was experienced. No adverse infectious or inflammatory events occurred during treatment with Optimel. Conclusions Optimel was a safe and effective adjunctive therapeutic strategy in the management of persistent post-operative corneal oedema and warrants further investigation in clinical trials.

Association of NOS1AP variants and depression phenotypes in schizophrenia

Background The nitric oxide synthase 1 adaptor protein gene (NOS1AP) has previously been recognised as a schizophrenia susceptibility gene due to its role in glutamate neurotransmission. The gene is believed to inhibit nitric oxide (NO) production activated by the N-methyl-d-aspartate (NMDA) receptor and reduced NO levels have been observed in schizophrenia patients. However, association studies investigating NOS1AP and schizophrenia have produced inconsistent results, most likely because schizophrenia is a clinically heterogeneous disorder. This study aims to investigate the association between NOS1AP variants and defined depression phenotypes of schizophrenia. Methods Nine NOS1AP SNPs, rs1415259, rs1415263, rs1858232, rs386231, rs4531275, rs4656355, rs4657178, rs6683968 and rs6704393 were genotyped in 235 schizophrenia subjects screened for various phenotypes of depression. Result One NOS1AP SNP (rs1858232) was associated with the broad diagnosis of schizophrenia and eight SNPs were associated with depression related phenotypes within schizophrenia. The rs1415259 SNP showed strong association with sleep dysregulation phenotypes of depression. Conclusion Results suggest that NOS1AP variants are associated with various forms of depression in schizophrenia and are more prevalent in males. Limitation Schizophrenia is a clinically heterogeneous disease that can vary greatly between different ethnic and geographic populations so our observations should be viewed with caution until they are independently replicated, particularly in larger patient cohorts.

A genetic variant of MDM4 influences regulation by multiple microRNAs in prostate cancer

The oncogene MDM4, also known as MDMX or HDMX, contributes to cancer susceptibility and progression through its capacity to negatively regulate a range of genes with tumour-suppressive functions. As part of a recent genome-wide association study it was determined that the A-allele of the rs4245739 SNP (A>C), located in the 3'-UTR of MDM4, is associated with an increased risk of prostate cancer. Computational predictions revealed that the rs4245739 SNP is located within a predicted binding site for three microRNAs (miRNAs): miR-191-5p, miR-887 and miR-3669. Herein, we show using reporter gene assays and endogenous MDM4 expression analyses that miR-191-5p and miR-887 have a specific affinity for the rs4245739 SNP C-allele in prostate cancer. These miRNAs do not affect MDM4 mRNA levels, rather they inhibit its translation in C-allele-containing PC3 cells but not in LNCaP cells homozygous for the A-allele. By analysing gene expression datasets from patient cohorts, we found that MDM4 is associated with metastasis and prostate cancer progression and that targeting this gene with miR-191-5p or miR-887 decreases in PC3 cell viability. This study is the first, to our knowledge, to demonstrate regulation of the MDM4 rs4245739 SNP C-allele by two miRNAs in prostate cancer, and thereby to identify a mechanism by which the MDM4 rs4245739 SNP A-allele may be associated with an increased risk for prostate cancer.

Breastmilk-saliva interactions boost innate immunity by regulating the oral microbiome in early infancy

Introduction Xanthine oxidase (XO) is distributed in mammals largely in the liver and small intestine, but also is highly active in milk where it generates hydrogen peroxide (H2O2). Adult human saliva is low in hypoxanthine and xanthine, the substrates of XO, and high in the lactoperoxidase substrate thiocyanate, but saliva of neonates has not been examined. Results Median concentrations of hypoxanthine and xanthine in neonatal saliva (27 and 19 μM respectively) were ten-fold higher than in adult saliva (2.1 and 1.7 μM). Fresh breastmilk contained 27.3±12.2 μM H2O2 but mixing baby saliva with breastmilk additionally generated >40 μM H2O2, sufficient to inhibit growth of the opportunistic pathogens Staphylococcus aureus and Salmonella spp. Oral peroxidase activity in neonatal saliva was variable but low (median 7 U/L, range 2–449) compared to adults (620 U/L, 48–1348), while peroxidase substrate thiocyanate in neonatal saliva was surprisingly high. Baby but not adult saliva also contained nucleosides and nucleobases that encouraged growth of the commensal bacteria Lactobacillus, but inhibited opportunistic pathogens; these nucleosides/bases may also promote growth of immature gut cells. Transition from neonatal to adult saliva pattern occurred during the weaning period. A survey of saliva from domesticated mammals revealed wide variation in nucleoside/base patterns. Discussion and Conclusion During breast-feeding, baby saliva reacts with breastmilk to produce reactive oxygen species, while simultaneously providing growth-promoting nucleotide precursors. Milk thus plays more than a simply nutritional role in mammals, interacting with infant saliva to produce a potent combination of stimulatory and inhibitory metabolites that regulate early oral–and hence gut–microbiota. Consequently, milk-saliva mixing appears to represent unique biochemical synergism which boosts early innate immunity.

GABAB Receptor antagonist CGP46381 inhibits form-deprivation myopia development in guinea pigs

The aim was to investigate the effects of the GABAB receptor antagonist, CGP46381, on form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs had monocular visual deprivation induced using a diffuser for 11 days (day 14 to 25). The deprived eyes were treated with daily subconjunctival injections (100 μl) of either 2% CGP46381, 0.2% CGP46381, or saline or received no injection. The fellow eyes were left untreated. Another six animals received no treatment. At the start and end of the treatment period, ocular refractions were measured using retinoscopy and vitreous chamber depth (VCD) and axial length (AL) using A-scan ultrasound. All of the deprived eyes developed relative myopia (treated versus untreated eyes, P < 0.05). The amount of myopia was significantly affected by the drug treatment (one-way ANOVA, P < 0.0001). The highest dose tested, 2% CGP46381, significantly inhibited myopia development compared to saline (2% CGP46381: -1.08 ± 0.40 D, saline: -4.33 ± 0.67 D, P < 0.01). The majority of these effects were due to less AL (2% CGP46381: 0.03 ± 0.01 mm, saline: 0.13 ± 0.02 mm, P < 0.01) and VCD (2% CGP46381: 0.02 ± 0.01 mm, saline: 0.08 ± 0.01 mm, P < 0.01) elongation. The lower dose tested, 0.2% CGP46381, did not significantly inhibit FDM (P > 0.05). Subconjunctival injections of CGP46381 inhibit FDM development in guinea pigs in a dose-dependent manner.

Evaluation of transgenic bananas expressing anti-apoptotic genes for resistance against Fusarium wilt

The banana industry worldwide is under threat from a fungal disease known as Fusarium wilt, a disease for which there is no chemical control. Conventional breeding approaches to generate resistant banana varieties are lengthy and very difficult. As such, genetic engineering for disease resistance is considered the most viable control option. In this PhD thesis, genetically modified banana plants were generated using several different stress tolerance genes. When challenged with Fusarium wilt in glasshouse trials, some lines showed increased resistance to the disease. The promising elite lines generated in this study will now require testing in field trials.

The effect of polyterpenol thin film surfaces on bacterial viability and adhesion

The nanometer scale surface topography of a solid substrate is known to influence the extent of bacterial attachment and their subsequent proliferation to form biofilms. As an extension of our previous work on the development of a novel organic polymer coating for the prevention of growth of medically significant bacteria on three-dimensional solid surfaces, this study examines the effect of surface coating on the adhesion and proliferation tendencies of Staphylococcus aureus and compares to those previously investigated tendencies of Pseudomonas aeruginosa on similar coatings. Radio frequency plasma enhanced chemical vapor deposition was used to coat the surface of the substrate with thin film of terpinen-4-ol, a constituent of tea-tree oil known to inhibit the growth of a broad range of bacteria. The presence of the coating decreased the substrate surface roughness from approximately 2.1 nm to 0.4 nm. Similar to P. aeruginosa, S. aureus presented notably different patterns of attachment in response to the presence of the surface film, where the amount of attachment, extracellular polymeric substance production, and cell proliferation on the coated surface was found to be greatly reduced compared to that obtained on the unmodified surface. This work suggests that the antimicrobial and antifouling coating used in this study could be effectively integrated into medical and other clinically relevant devices to prevent bacterial growth and to minimize bacteria-associated adverse host responses.

Proinflammatory cytokines regulate cementogenic differentiation of periodontal ligament cells by Wnt/Ca2+ signaling pathway

Periodontal inflammation can inhibit cell differentiation of periodontal ligament cells (PDLCs), resulting in decreased bone/cementum regeneration ability. The Wnt signaling pathway, including canonical Wnt/β-catenin signaling and noncanonical Wnt/Ca2+ signaling, plays essential roles in cell proliferation and differentiation during tooth development. However, little is still known whether noncanonical Wnt/Ca2+ signaling cascade could regulate cementogenic/osteogenic differentiation capability of PDLCs within an inflammatory environment. Therefore, in this study, human PDLCs (hPDLCs) and their cementogenic differentiation potential were investigated in the presence of cytokines. The data demonstrated that both cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) inhibited cell proliferation, relative alkaline phosphatase activity, bone/cementum-related gene/protein expression, and canonical Wnt pathway-related gene/protein expression in hPDLCs. Interestingly, both cytokines upregulated the noncanonical Wnt/Ca2+ signaling-related gene and protein expression in hPDLCs. When the Wnt/Ca2+ pathway was blocked by Ca2+/calmodulin-dependent protein kinase II inhibitor KN93, even in the presence of IL-6 and TNF-α, cementogenesis could be stimulated in hPDLCs. Our data indicate that the Wnt/Ca2+ pathway plays an inhibitory role on PDLC cementogenic differentiation in inflammatory microenvironments. Therefore, targeting the Wnt/Ca2+ pathway may provide a novel therapeutic approach to improve periodontal regeneration for periodontal diseases.

Protection of a Static Frequency Converter fed traction network, a case study

Aurizon, Australia's largest rail freight operator, is introducing the Static Frequency Converter (SFC) technology into its electric railway network as part of the Bauhinia Electrification Project. The introduction of SFCs has significant implications on the protection systems of the 50kV traction network. The traditional distance protection calculation method does not work in this configuration because of the effect that the SFC in combination with the remote grid has on the apparent impedance, and was substantially reviewed. The standard overcurrent (OC) protection scheme is not suitable due to the minimum fault level being below the maximum load level and was revised to incorporate directionality and under-voltage inhibit. Delta protection was reviewed to improve sensitivity. A new protection function was introduced to prevent back-feeding faults in the transmission network through the grid connection. Protection inter-tripping was included to ensure selectivity between the SFC protection and the system downstream.

Medication incident reporting in residential aged care facilities: Limitations and risks to residents' safety

Background Medication incident reporting (MIR) is a key safety critical care process in residential aged care facilities (RACFs). Retrospective studies of medication incident reports in aged care have identified the inability of existing MIR processes to generate information that can be used to enhance residents’ safety. However, there is little existing research that investigates the limitations of the existing information exchange process that underpins MIR, despite the considerable resources that RACFs’ devote to the MIR process. The aim of this study was to undertake an in-depth exploration of the information exchange process involved in MIR and identify factors that inhibit the collection of meaningful information in RACFs. Methods The study was undertaken in three RACFs (part of a large non-profit organisation) in NSW, Australia. A total of 23 semi-structured interviews and 62 hours of observation sessions were conducted between May to July 2011. The qualitative data was iteratively analysed using a grounded theory approach. Results The findings highlight significant gaps in the design of the MIR artefacts as well as information exchange issues in MIR process execution. Study results emphasized the need to: a) design MIR artefacts that facilitate identification of the root causes of medication incidents, b) integrate the MIR process within existing information systems to overcome key gaps in information exchange execution, and c) support exchange of information that can facilitate a multi-disciplinary approach to medication incident management in RACFs. Conclusions This study highlights the advantages of viewing MIR process holistically rather than as segregated tasks, as a means to identify gaps in information exchange that need to be addressed in practice to improve safety critical processes.