Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis , is the leading cause of mortality worldwide due to a single infectious agent. The pathogen spreads primarily via aerosols and especially infects the alveolar macrophages in the lungs. The lung has evolved various biological mechanisms, including oxidative stress (OS) responses, to counteract TB infection. M. tuberculosis infection triggers the generation of reactive oxygen species by host phagocytic cells (primarily macrophages). The development of resistance to commonly prescribed antibiotics poses a challenge to treat TB; this commonly manifests as multidrug resistant tuberculosis (MDR‐TB). OS and antioxidant defense mechanisms play key roles during TB infection and treatment. For instance, several established first‐/second‐line antitubercle antibiotics are administered in an inactive form and subsequently transformed into their active form by components of the OS responses of both host (nitric oxide, S ‐oxidation) and pathogen (catalase/peroxidase enzyme, EthA). Additionally, M. tuberculosis has developed mechanisms to survive high OS burden in the host, including the increased bacterial NADH/NAD + ratio and enhanced intracellular survival (Eis) protein, peroxiredoxin, superoxide dismutases, and catalases. Here, we review the interplay between lung OS and its effects on both activation of antitubercle antibiotics and the strategies employed by M. tuberculosis that are essential for survival of both drug‐susceptible and drug‐resistant bacterial subtypes. We then outline potential new therapies that are based on combining standard antitubercular antibiotics with adjuvant agents that could limit the ability of M. tuberculosis to counter the host’s OS response.
Inflammatory bowel diseases (IBD), such as ulcerative colitis and Crohn’s disease, are an important cause of morbidity and impact significantly on quality of life. Overall, current treatments do not sustain a long-term clinical remission and are associated with adverse effects, which highlight the need for new treatment options. Fucoidans are complex sulphated, fucose-rich polysaccharides, found in edible brown algae and are described as having multiple bioactivities including potent anti-inflammatory effects. Therefore, the therapeutic potential of two different fucoidan preparations, fucoidan-polyphenol complex (Maritech Synergy) and depyrogenated fucoidan (DPF) was evaluated in the dextran sulphate sodium (DSS) mouse model of acute colitis. Mice were treated once daily over 7 days with fucoidans via oral (Synergy or DPF) or intraperitoneal administration (DPF). Signs and severity of colitis were monitored daily before colons and spleens were collected for macroscopic evaluation, cytokine measurements and histology. Orally administered Synergy and DPF, but not intraperitoneal DPF treatment, significantly ameliorated symptoms of colitis based on retention of body weight, as well as reduced diarrhoea and faecal blood loss, compared to the untreated colitis group. Colon and spleen weight in mice treated with oral fucoidan was also significantly lower, indicating reduced inflammation and oedema. Histological examination of untreated colitis mice confirmed a massive loss of crypt architecture and goblet cells, infiltration of immune cells and oedema, while all aspects of this pathology were alleviated by oral fucoidan. Importantly, in this model, the macroscopic changes induced by oral fucoidan correlated significantly with substantially decreased production of at least 15 pro-inflammatory cytokines by the colon tissue. Overall, oral fucoidan preparations significantly reduce the inflammatory pathology associated with DSS-induced colitis and could therefore represent a novel nutraceutical option for the management of IBD.
Ciprofloxacin, a second-generation broad spectrum fluoroquinolone, is active against both Gram-positive and Gram-negative bacteria. Ciprofloxacin has a high oral bioavailability and a large volume of distribution. It is used for the treatment of a wide range of infections including urinary tract infections caused by susceptible bacteria. However, the substandard and spurious quality of oral ciprofloxacin formulations in the developing countries has been thought to have contributed towards increased risk of treatment failure and bacterial resistance. Therefore, quality control and bioequivalence studies of the commercially available oral ciprofloxacin formulations should be monitored. Appropriate actions should be taken against offending manufacturers in order to prevent the sale of substandard medications, especially the spurious oral ciprofloxacin products.
23 May 2014 in Expert Review of Respiratory Medicine
Chronic obstructive pulmonary disease (COPD) is a complex condition, frequently with a mix of airway and lung parenchymal damage. However, the earliest changes are in the small airways, where most of the airflow limitation occurs. The pathology of small airway damage seems to be wall fibrosis and obliteration, but the whole airway is involved in a 'field effect'. Our novel observations on active epithelial-mesenchymal transition (EMT) in the airways of smokers, particularly in those with COPD, are changing the understanding of this airway pathology and the aetiology of COPD. EMT involves a cascade of regulatory changes that destabilise the epithelium with a motile and mesenchymal epithelial cell phenotype emerging. One important manifestation of EMT activity involves up-regulation of specific key transcription factors (TFs), such as Smads, Twist, and β-catenin. Such TFs can be used as EMT biomarkers, in recognisable patterns reflecting the potential major drivers of the process; for example, TGFβ, Wnt, and integrin-linked kinase systems. Thus, understanding the relative changes in TF activity during EMT may provide rich information on the mechanisms driving this whole process, and how they may change over time and with therapy. We have sought to review the current literature on EMT and the relative expression of specific TF activity, to define the networks likely to be involved in a similar process in the airways of patients with smoking-related COPD.
Health literacy (HL) is an essential component of various literacies mentioned in the field of health and education, including cultural, technological, media and scientific literacies. It is important for motivating higher consumer engagement. We aimed to review previous studies of HL in Australia to inform future studies, extend current knowledge and further enhance HL. Using search strings, a systematic search of four databases (i.e., MEDLINE; Embase; CINAHL and Eric) was carried out. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) based search strategy led to identification of a total of N = 9696 records, that were further screened for inclusion in the review. The review findings were categorized into three major themes: (1) HL and health numeracy; (2) contrast of: knowledge deficiency, knowledge gained, problems of current health care system and (3) HL measurement methods and its domains. The findings from this scoping review show a dearth of measurement tools with sound psychometric properties for assessing HL. The findings also reveal low levels of HL in consumers which is in turn affecting health-related behaviors, utilization of health services and navigation of the health system. More recent developments have tried to integrate vital aspects, including introduction of applications to increase HL and exploring HL in Aboriginal communities.
1 January 2008 in Journal of Pharmaceutical and Biomedical Analysis