Fire exclusion and the changing landscape of Queensland’s Wet Tropics Bioregion 1. The extent and pattern of transition

The vegetation and geology of the Wet Tropics Bioregion of North Queensland, covering 1?998?150 ha, were mapped at a scale of 1:50?000. The resulting geographic information system (GIS) data base provided an unprecedented opportunity to examine vegetation condition across the entire bioregion. Mapping used colour aerial photography at 1:25?000, informed by ground truthing. Vegetation type, nature of the understory and ground cover, degree and type of disturbance, and the presence of secondary vegetation were described by a coding system, with codes marked directly on the aerial photos.

Analysis of these data has confirmed a picture, which emerged from ground truthing, of large areas of sclerophyll woodland and forest being invaded by a rainforest understory that prevents regeneration of the sclerophyll canopy. Fifty-three per cent of the native vegetation of the bioregion consists of non-rainforest vegetation types, dominated in both area and number by sclerophyll woodlands and forests. Seventeen per cent of the 735?713 ha of sclerophyll woodland and forest types were assessed as having suffered irreversible change. Between 25% and 79% of individual forest vegetation types were judged to have been affected by irreversible change. No climatic changes, or changes in the environment, apart from those related to changing fire regimes, were identified as causative factors. Changed fire regimes, predominantly fire exclusion, are considered to be the most likely cause.     

Identification of risk factors associated with postoperative acute kidney injury after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a retrospective study

Background: Acute kidney injury (AKI) is a postoperative complication associated with significant morbidity and mortality. The incidence and risks factors for AKI after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) have not been fully studied. The purpose of this study was to identify perioperative risk factors predictive of AKI after CRS-HIPEC.

Methods: This retrospective study collected demographic, tumour-related, intraoperative and postoperative data from 475 patients who underwent CRS-HIPECs. AKI was defined using the acute kidney injury network criteria and calculated on postoperative days 1, 2, 3, 7 and day of hospital discharge. We conducted univariate and multivariate analyses to assess the association between variables of interest and AKI. A p value of <0.05 was considered statistically significant.

Results: The incidence of AKI was 21.3%. The multivariate analysis identified six predictor factors independently associated with the development of AKI (OR: [95%CI]); age: 1.16 (1.05–1.29, p?p?=?0.05) and obesity: 2.88 (1.47–5.63), p?p?p?p?p?Conclusions: Our study demonstrates that the incidence of AKI is high. While other studies have reported that AKI is associated with platinum-based infusion, age and obesity, we report for the first time a negative association between pregabalin use and AKI. More studies are needed to confirm our results.     

Relationship of health locus of control with specific health behaviours and global health appraisal: a meta-analysis and effects of moderators

Health locus of control (HLOC) refers to beliefs regarding how one’s health is influenced by oneself, others, or fate. This meta-analysis investigated whether three HLOC dimensions (internality/I-HLOC, powerful others/P-HLOC, chance/C-HLOC) were related to both specific health behaviours and global health appraisal, and whether these relationships were moderated by gender and age compositions, individualism, and power distance. Three-level mixed-effects meta-analysis was performed on studies examining the associations of HLOC with specific health behaviour (k?=?76, N?=?76,580, 57% women, M_age?=?43.75) and global health appraisal (k?=?95, N?=?12,068, 57% women, M_age?=?45.44), respectively. For specific health behaviour, the averaged correlations with the HLOC dimensions were generally weak (r’s?=??.07 to .10). However, the links between P-HLOC and exercise were moderated by all four demographic moderators, and gender composition and individualism moderated the association between the HLOC dimensions and diet. For global health appraisal, all of the averaged correlations were statistically significant (r’s?=??.16 to .21), except that between P-HLOC and mental quality of life. The results further showed individualism and power distance to moderate the links between the HLOC dimensions and both mental and physical quality of life, and gender composition to moderate those between these dimensions and two indicators of emotional problems (depression and anxiety).     

Experience developing national evidence-based clinical guidelines for childhood pneumonia in a low-income setting - making the GRADE?

Background  

The development of evidence-based clinical practice guidelines has gained wide acceptance in high-income countries and reputable international organizations. Whereas this approach may be a desirable standard, challenges remain in low-income settings with limited capacity and resources for evidence synthesis and guideline development. We present our experience using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach for the recent revision of the Kenyan pediatric clinical guidelines focusing on antibiotic treatment of pneumonia.     

The role of the microbiota in periodontal disease

The last decade has witnessed unparalleled advances in our understanding of the complexity of the oral microbiome and the compositional changes that occur in subgingival biofilms in the transition from health to gingivitis and to destructive periodontal disease. The traditional view, which has held sway for the last 2 decades, that disease is characterized by the outgrowth of a consortium, or consortia, of a limited number of potentially pathogenic organisms, has given way to an alternative paradigm. In this new view, the microbiological changes associated with disease represent whole-scale alterations to the overall microbial population structure and to the functional properties of the entire community. Thus, and in common with other microbially mediated diseases of the gastrointestinal tract, the normally balanced, symbiotic, and generally benign commensal microbiome of the tooth-associated biofilm undergoes dysbiosis to a potentially deleterious microbiota. Coincident with progress in defining the microbiology of these diseases, there have been equally important advances in our understanding of the inflammatory systems of the periodontal tissues, their control, and how inflammation may contribute both to the development of dysbiosis and, in a deregulated state, the destructive disease process. One can therefore speculate that the inflammatory response and the periodontal microbiome are in a bidirectional balance in oral health and a bidirectional imbalance in periodontitis. However, despite these clear insights into both sides of the host/microbe balance in periodontal disease, there remain several unresolved issues concerning the role of the microbiota in disease. These include, but are not limited to, the factors which determine progression from gingivitis to periodontitis in a proportion of the population, whether dysbiosis causes disease or results from disease, and the molecular details of the microbial stimulus responsible for driving the destructive inflammatory response. Further progress in resolving these issues may provide significant benefit to diagnosis, treatment, and prevention.     

Selective β-adrenergic Receptor Expression on Human Memory CD8+ T Lymphocyte Subsets Regulates Mobilization and INF-y Production

Introduction: CD8⁺ T lymphocytes (CD8TLs) express β-adrenergic receptors (βAR), which bind the neurotransmitter norepinephrine and stress hormone epinephrine released during inflammation, trauma, and psychological stress. Little is known about the functions of this βAR expression on CD8TLs. Methods: Volunteers were exposed to a psychological stressor (N=24). Flow cytometry identified CD8TL subsets by CCR7, CD27, CD28 and CD45RA expression. Adrenergic receptor subtype expression was determined by micro-array. The effects of βPAR stimulation on IFN-γ production in activated CD8TLs was tested in vitro using PMA/Ionomycin. Results: Stress caused selective migration of effector-memory (CCR7⁻CD27⁻CD28⁻) CD8TLs into the blood (+148%, p<.001). An 8-fold up-regulation of the β₂AR was demonstrated in effector-memory cells as compared to naïve CD8TLs. Stimulation of the β₂AR subtype completely inhibited IFN-γ production. Conclusion: These results show that β₂AR stimulation enhances peripheral immune surveillance in a highly selective manner, and might protect against excessive cytokine release during inflammation and stress.