Dry season habitat use of fishes in an Australian tropical river.

The modification of river flow regimes poses a significant threat to the world's freshwater ecosystems. Northern Australia's freshwater resources, particularly dry season river flows, are being increasingly modified to support human development, potentially threatening aquatic ecosystems and biodiversity, including fish. More information is urgently needed on the ecology of fishes in this region, including their habitat requirements, to support water policy and management to ensure future sustainable development. This study used electrofishing and habitat survey methods to quantify the dry season habitat use of 20 common freshwater fish taxa in the Daly River in Australia's wet-dry tropics. Of twenty measured habitat variables, water depth and velocity were the two most important factors discriminating fish habitat use for the majority of taxa. Four distinct fish habitat guilds were identified, largely classified according to depth, velocity and structural complexity. Ontogenetic shifts in habitat use were also observed in three species. This study highlights the need to maintain dry season river flows that support a diversity of riverine mesohabitats for freshwater fishes. In particular, shallow fast-flowing areas provided critical nursery and refuge habitats for some species, but are vulnerable to water level reductions due to water extraction. By highlighting the importance of a diversity of habitats for fishes, this study assists water managers in future decision making on the ecological risks of water extractions from tropical rivers, and especially the need to maintain dry season low flows to protect the habitats of native fish.

Systematic review: the natural history of alpha-1 antitrypsin deficiency, and associated liver disease.

BACKGROUND: Alpha-1 antitrypsin deficiency (AATD) is estimated to affect three million people worldwide. It causes liver disease in a proportion of carriers of the PiS and PiZ allele due to the formation and retention of polymers within the endoplasmic reticulum of hepatocytes. The reason for this selective penetrance is not known. Although clinical trials are underway, liver transplantation is the only effective treatment for liver disease due to AATD. AIMS: To report the prevalence and natural history of liver disease among individuals with AATD, and assess the outcomes of liver transplantation through systematic review. METHODS: A comprehensive search was conducted across multiple databases. Two independent authors selected the articles and assessed bias using the Newcastle-Ottawa Scale. Data were pooled for analysis, where comparable outcomes were reported. RESULTS: Thirty-five studies were identified related to disease progression and 12 for the treatment of AATD. Seven per cent of children were reported to develop liver cirrhosis, with 16.5% of individuals presenting in childhood requiring liver transplantation. Of those surviving to adulthood, 10.5% had liver cirrhosis and 14.7% required transplantation. Liver transplantation was the only effective treatment reported and outcomes compare favourably to other indications, with 5-year survival reported as over 90% in children and over 80% in adults. DISCUSSION: The clinical course of liver disease in individuals with AATD remains poorly understood, but affects about 10% of those with AATD. More research is required to identify those patients at risk of developing liver disease at an early stage, and to provide alternative treatments to liver transplantation.

Hepatitis C Virus Recurrence Occurs Earlier in Patients Receiving Donation After Circulatory Death Liver Transplant Grafts Compared With Those Receiving Donation After Brainstem Death Grafts.

INTRODUCTION: Hepatitis C virus (HCV)-related cirrhosis remains the commonest indication for liver transplantation worldwide, yet few studies have investigated the impact of donation after circulatory death (DCD) graft use on HCV recurrence and patient outcomes. DCD grafts have augmented the limited donor organ pool and reduced wait-list mortality, although concerns regarding graft longevity and patient outcome persist. METHODS: This was a single-center study of all HCV + adults who underwent DCD liver transplantation between 2004 and 2014. 44 HCV+ patients received DCD grafts, and were matched with 44 HCV+ recipients of donation after brainstem death (DBD) grafts, and their outcomes examined. RESULTS: The groups were matched for age, sex, and presence of hepatocellular carcinoma; no significant differences were found between the group's donor or recipient characteristics. Paired and unpaired analysis demonstrated that HCV recurrence was more rapid in recipients of DCD organs compared with DBD grafts (408 vs 657 days; P = .006). There were no significant differences in graft survival, patient survival, or rates of biliary complications between the cohorts despite DCD donors being 10 years older on average than those used in other published experience. CONCLUSIONS: In an era of highly effective direct acting antiviral therapy, rapid HCV recrudescence in grafts from DCD donors should not compromise long-term morbidity or mortality. In the context of rising wait-list mortality, it is prudent to use all available sources to expand the pool of donor organs, and our data support the practice of using extended-criteria DCD grafts based on donor age. Notwithstanding that, clinicians should be aware that HCV recrudescence is more rapid in DCD recipients, and early post-transplant anti-viral therapy is indicated to prevent graft injury.

Review article: new treatments in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease is the fastest growing cause of liver disease in the Western world, yet there is no approved pharmacotherapy. While lifestyle modifications remain the mainstay of treatment, only a proportion of individuals are able to make or sustain them, and so more treatment options are required. AIM: To review the potential benefit of drugs used in clinical practice, those entering phase II trials, and compounds being investigated in pre-clinical studies. METHODS: A literature search was performed using PubMed to identify relevant studies; linked references were also reviewed. RESULTS: Vitamin E and pioglitazone have shown efficacy in non-alcoholic steatohepatitis (NASH), but long-term safety concerns, specifically bladder cancer and osteoporosis with pioglitazone, have limited their use. GLP-1 analogues and SGLT-2 inhibitors are currently approved for use in diabetes, have shown early efficacy in NASH and also have beneficial cardiovascular effects. Peroxisome proliferator-activator receptors and FXR agonists have potent effects on lipogenesis, inflammation and fibrosis, respectively, with their efficacy and safety being currently tested in phase 3. As inflammation and apoptosis are key features of NASH agents modulating these pathways are of interest; CCR2/5 antagonists downregulate inflammatory pathways and reduce fibrosis with caspase and apoptosis signal-regulating kinase 1 inhibitors reducing apoptosis and fibrosis. CONCLUSIONS: Rising demand and an improved understanding of NASH pathophysiology has led to a surge in development of new therapies. Tailoring pharmacotherapy to the dominant pathogenic pathway in a given patient along with use of combination therapy is likely to represent the future direction in treatment of patients with NASH.

Non-alcoholic fatty liver disease in 2016.

INTRODUCTION: Non-alcoholic fatty liver disease is the commonest cause of liver disease worldwide, and is rapidly becoming the leading indication for liver transplantation. SOURCES OF DATA: Original articles, reviews and meta-analyses, guidelines. AREAS OF AGREEMENT: NAFLD strongly correlates with obesity and insulin resistance; currently, the best management strategy is weight loss and treatment of the metabolic syndrome. AREAS OF CONTROVERSY: Recent data suggest that the presence of fibrosis and not non-alcoholic steatohepatitis (NASH) is the predictor of clinical outcome. GROWING POINTS: Many phase 2 and 3 trials are underway. Drugs hoped to be effective are obeticholic acid, elafibranor, glucagon-like peptide-1 analogues and CCR2/5 inhibitors. AREAS TIMELY FOR DEVELOPING RESEARCH: Improved understanding of the pathophysiology of NAFLD should help us identify which patients progress to significant liver disease and to develop therapies to target this population.

The relationships between salmonellas and faecal indicator concentrations in two pools in the Australian wet/dry tropics.

The relationships between total coliform, faecal coliform, enterococci and salmonella concentrations were investigated at Berry and Howard Pools in the Australian wet/dry tropics. Both pools have catchments with minimal human activity and no major point source of faecal pollution. Forty-five indicator and salmonella enumerations were made from each pool over a 1 year period. Salmonellas were isolated from 69% and 96% of samples collected from Howard and Berry Pools respectively, the maximum (MPN) concentration was 110/100 ml. Native fauna were the primary salmonella source. Spearman rank correlations between indicator organisms and salmonella at Howard Pool were significant at the 5% level and approximated 0.6. At Berry Pool, total coliform and enterococci Spearman rank correlations with salmonella were also statistically significant, approximating 0.3; faecal coliforms and salmonella rankings, however, were unrelated. The higher correlation coefficients at Howard Pool were attributed to its small catchment (4 km2) and the more recent nature of faecal contamination compared with Berry Pool which has a catchment of 130 km2. The results highlight the spatial variability of the indicator/pathogen numerical relationship. Total coliform and enterococci counts, as indicators of faecal pollution, were similar and more consistent than faecal coliforms.