Now showing 1 - 5 of 5
  • Publication
    Increased Neurotropic Threat from 'Burkholderia pseudomallei' Strains with a 'B mallei'-like Variation in the 'bimA' Motility Gene, Australia
    (Centers for Disease Control and Prevention (CDC), 2017)
    Morris, Jodie L
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    Fane, Anne
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    Sarovich, Derek S
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    Price, Erin P
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    Rush, Catherine M
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    Govan, Brenda L
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    Parker, Elizabeth
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    Mayo, Mark
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    Currie, Bart J
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    Neurologic melioidosis is a serious, potentially fatal form of Burkholderia pseudomallei infection. Recently, we reported that a subset of clinical isolates of B. pseudomallei from Australia have heightened virulence and potential for dissemination to the central nervous system. In this study, we demonstrate that this subset has a B. mallei-like sequence variation of the actin-based motility gene, bimA. Compared with B. pseudomallei isolates having typical bimA alleles, isolates that contain the B. mallei-like variation demonstrate increased persistence in phagocytic cells and increased virulence with rapid systemic dissemination and replication within multiple tissues, including the brain and spinal cord, in an experimental model. These findings highlight the implications of bimA variation on disease progression of B. pseudomallei infection and have considerable clinical and public health implications with respect to the degree of neurotropic threat posed to human health.
  • Publication
    Anti-mycobacterial function of macrophages is impaired in a diet induced model of type 2 diabetes
    (Elsevier Ltd, 2017)
    Alim, Md Abdul
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    Sikder, Suchandan
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    Bridson, Tahnee L
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    Rush, Catherine M
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    Govan, Brenda L
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    Type 2 diabetes (T2D) is one of the major risk factors for tuberculosis (TB). In this study, a diet induced murine model of T2D (DIMT2D) was developed and characterized in the context of metabolic, biochemical and histopathological features following diet intervention. Mycobacterial susceptibility was investigated using Mycobacterium fortuitum as a surrogate. Phagocytic capability of alveolar macrophages and resident peritoneal macrophages were determined by in vitro assays using mycolic acid coated beads and M. fortuitum. Results demonstrated that bacillary loads were significantly higher in liver, spleen, and lungs of diabetic mice compared to controls. Higher inflammatory lesions and impaired cytokine kinetics (TNF-α, MCP-1, IL-12, IFN-γ) were also observed in diabetic mice. Macrophages isolated from diabetic mice had lower uptake of mycolic acid coated beads, reduced bacterial internalization and killing and altered cytokine responses (TNF-α, IL-6, MCP-1). This model will be useful to further investigate different facets of host-pathogen interactions in TB-T2D.
  • Publication
    Anti-troponin antibodies following myocardial infarction
    (Elsevier BV, 2017)
    O'Donohoe, Tom J
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    Schrale, Ryan G
    Recent improvements in medical and surgical coronary revascularization techniques have significantly improved outcomes for patients with acute myocardial infarction (MI). However, large infarctions are often followed by a poorly understood process of pathological ventricular remodelling, which fails to return the heart to its premorbid state. Although it remains incompletely understood, there is increasing interest in the role of the immune system in this process. One hypothesis is that released cardiac proteins become the focus of an immune response that results in the formation of functionally significant autoantibodies. This review summarizes the current literature, both human and animal, relating to the formation and clinical relevance of anti-troponin antibodies (ATAs) in patients with MI.
  • Publication
    Therapeutic effect of quercetin in collagen-induced arthritis
    (Elsevier Masson, 2017)
    Haleagrahara, Nagaraja
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    Miranda-Hernandez, Socorro
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    Alim, Md Abdul
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    Hayes, Linda
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    Bird, Guy
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    Quercetin, a bioactive flavonoid with anti-inflammatory, immunosuppressive,and protective properties, is a potential agent for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis (CIA) is the most commonly used animal model for studying the pathogenesis of RA. This study analysed the therapeutic role of quercetin in collagen-induced arthritis in C57BL/6 mice. The animals were allocated into five groups that were subjected to the following treatments: negative (untreated) control, positive control (arthritis-induced), arthritis+methotrexate, arthritis+quercetin, and arthritis+methotrexate+quercetin. Assessments of weight, oedema, joint damage, and cytokine production were used to determine the therapeutic effect of quercetin. This study demonstrated for the first time the anti-inflammatory and protective effects of quercetin in vivo in CIA. The results also showed that the concurrent administration of quercetin and methotrexate did not offer greater protection than the administration of a single agent. The use of quercetin as a monotherapeutic agent resulted in the lowest degree of joint inflammation and the highest protection.The reduced severity of the disease in animals treated with quercetin was associated with decreased levels of TNF-α, IL-1 β, IL-17, and MCP-1. In conclusion, this study determined that quercetin, which was non-toxic, produced better results than methotrexate for the protection of joints from arthritic inflammation in mice. Quercetin may be an alternative treatment for RA because it modulates the main pathogenic pathways of RA.
  • Publication
    The therapeutic potential of plant flavonoids on rheumatoid arthritis
    (Taylor & Francis Inc, 2017)
    Hughes, Samuel D
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    Haleagrahara, Nagaraja
    Rheumatoid arthritis (RA) is an autoimmune condition that mainly affects peripheral joints. Although immunosuppressive drugs and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat this condition, these drugs have severe side effects. Flavonoids are the most abundant phenolic compounds which exhibit anti-oxidant, anti-inflammatory and immunomodulatory properties. Many bioactive flavonoids have powerful anti-inflammatory effects. However, a very few have reached clinical use. Dietary flavonoids have been reported to control joint inflammation and alleviate arthritis symptoms in both human RA and animal models of arthritis. There is little scientific evidence about their mechanism of actions in RA. We review the therapeutic effects of different groups of flavonoids belonging to the most common and abundant groups on RA. In particular, the probable mechanisms of major flavonoids on cells and chemical messengers involved in the inflammatory signaling components of RA are discussed in detail.