Differential modulation of microglia superoxide anion and thromboxane B(2 )generation by the marine manzamines

BACKGROUND: Thromboxane B(2 )(TXB(2)) and superoxide anion (O(2)(-)) are neuroinflammatory mediators that appear to be involved in the pathogenesis of several neurodegenerative diseases. Because activated-microglia are the main source of TXB(2 )and O(2)(- )in these disorders, modulation of their synthesis has been hypothesized as a potential therapeutic approach for neuroinflammatory disorders. Marine natural products have become a source of novel agents that modulate eicosanoids and O(2)(- )generation from activated murine and human leukocytes. With the exception of manzamine C, all other manzamines tested are characterized by a complex pentacyclic diamine linked to C-1 of the β-carboline moiety. These marine-derived alkaloids have been reported to possess a diverse range of bioactivities including anticancer, immunostimulatory, insecticidal, antibacterial, antimalarial and antituberculosis activities. The purpose of this investigation was to conduct a structure-activity relationship study with manzamines (MZ) A, B, C, D, E and F on agonist-stimulated release of TXB(2 )and O(2)(- )from E. coli LPS-activated rat neonatal microglia in vitro. RESULTS: The manzamines differentially attenuated PMA (phorbol 12-myristate 13-acetate)-stimulated TXB(2 )generation in the following order of decreasing potency: MZA (IC(50 )<0.016 μM) >MZD (IC(50 )= 0.23 μM) >MZB (IC(50 )= 1.6 μM) >MZC (IC(50 )= 2.98 μM) >MZE and F (IC(50 )>10 μM). In contrast, there was less effect on OPZ (opsonized zymosan)-stimulated TXB(2 )generation: MZB (IC(50 )= 1.44 μM) >MZA (IC(50 )= 3.16 μM) >MZC (IC(50 )= 3.34 μM) >MZD, MZE and MZF (IC(50 )>10 μM). Similarly, PMA-stimulated O(2)(- )generation was affected differentially as follows: MZD (apparent IC(50)<0.1 μM) >MZA (IC(50 )= 0.1 μM) >MZB (IC(50 )= 3.16 μM) >MZC (IC(50 )= 3.43 μM) >MZE and MZF (IC(50 )>10 μM). In contrast, OPZ-stimulated O(2)(- )generation was minimally affected: MZB (IC(50 )= 4.17 μM) >MZC (IC(50 )= 9.3 μM) >MZA, MZD, MZE and MZF (IC(50 )> 10 μM). From the structure-activity relationship perspective, contributing factors to the observed differential bioactivity on TXB(2 )and O(2)(- )generation are the solubility or ionic forms of MZA and D as well as changes such as saturation or oxidation of the β carboline or 8-membered amine ring. In contrast, the fused 13-membered macrocyclic and isoquinoline ring system, and any substitutions in these rings would not appear to be factors contributing to bioactivity. CONCLUSION: To our knowledge, this is the first experimental study that demonstrates that MZA, at in vitro concentrations that are non toxic to E. coli LPS-activated rat neonatal microglia, potently modulates PMA-stimulated TXB(2 )and O(2)(- )generation. MZA may thus be a lead candidate for the development of novel therapeutic agents for the modulation of TXB(2 )and O(2)(- )release in neuroinflammatory diseases. Marine natural products provide a novel and rich source of chemical diversity that can contribute to the design and development of new and potentially useful anti-inflammatory agents to treat neurodegenerative diseases

Using rapid damage observations for Bayesian updating of hurricane vulnerability functions: A case study of Hurricane Dorian using social media

Rapid impact assessments immediately after disasters are crucial to enable rapid and effective mobilization of resources for response and recovery efforts. These assessments are often performed by analysing the three components of risk: hazard, exposure and vulnerability. Vulnerability curves are often constructed using historic insurance data or expert judgments, reducing their applicability for the characteristics of the specific hazard and building stock. Therefore, this paper outlines an approach to the creation of event-specific vulnerability curves, using Bayesian statistics (i.e., the zero-one inflated beta distribution) to update a pre-existing vulnerability curve (i.e., the prior) with observed impact data derived from social media. The approach is applied in a case study of Hurricane Dorian, which hit the Bahamas in September 2019. We analysed footage shot predominantly from unmanned aerial vehicles (UAVs) and other airborne vehicles posted on YouTube in the first 10 days after the disaster. Due to its Bayesian nature, the approach can be used regardless of the amount of data available as it balances the contribution of the prior and the observations

INdigenous Systems and Policies Improved and Reimagined for Ear and hearing care (INSPIRE): A multi-method study protocol

Introduction Otitis media (middle ear disease) severity and chronicity among Aboriginal and Torres Strait Islander people, as well as gaps in socioeconomic outcomes related to hearing loss, indicates a breakdown in the current ear and hearing care system. The ear and hearing care system spans multiple sectors due to long-term impacts of otitis media and hearing loss in health, education and employment, necessitating a multi-disciplinary cross-sectorial approach to ear and hearing care. Public policies shape the current ear and hearing care system and here it is argued that a critical public policy analysis across different sectors is needed, with strong Aboriginal and Torres Strait Islander leadership and guidance. The current study aims to establish consensus-based ear and hearing care policy solutions for Aboriginal and Torres Strait Islander people in Australia. Methods and analysis This multi-method study will be guided by a Brains Trust with strong Aboriginal and Torres Strait Islander leadership. Public policies in hearing health, social services, and education will be scoped to identify policy gaps, using the World Health Organization framework. Qualitative data will be collected through a culturally specific process of yarning circles to identify policy challenges and/or limitations in enabling accessible ear and hearing care programs/services for Aboriginal and Torres Strait Islander people, using dimensions of Morestin's public policy appraisal tool as an interview guide for stakeholders. Themes from the yarning circles will be used to inform an expert Delphi process to establish consensus-based policy solutions for optimising the ear and hearing care system for Aboriginal and Torres Strait Islander people. Ethics and dissemination This study has approval from the Australian Institute of Aboriginal and Torres Strait Islander Studies Ethics Committee. Study findings will be disseminated to community through Brains Trust members and study participants, as well as through publications in peer-reviewed journals and research forum presentations

An audit of specimens received for superficial fungal studies to the Department of Microbiology, University of Ruhuna

NA

Development and validation of a reference marker for identification of aerobic and anaerobic bacteria associated with diabetes chronic wound ulcers using PCR denaturing gradient gel electrophoresis

Introduction: Diabetes chronic wounds consist with a diverse microbial community and unculturablespecies may be highly prevalent.Objectives: This study aimed to establish a bacterial reference marker consisting of a group ofchronic wound related bacteria, using polymerase chain reaction-denaturing gradient gelelectrophoresis (PCR-DGGE) for profiling of bacteria in diabetes chronic wound infections.Methods: DNA was extracted from the known wound bacterial strains. PCR–DGGE was performedusing eubacterial specific primers targeting V2-V3 region of 16S rDNA. DGGE was performed usinga 30-55% denaturing gradient. Migration position of each organism was detected on DGGE gel andimportant organisms were selected. Equal volume from PCR products of each selected organism wasmixed, diluted with gel loading dye in 1:1.5 ratio and used for all DGGE gels. The ladder was thensubjected to species identification of fifteen tissue debridement specimens obtained from diabeteschronic wound ulcers. The identification efficacy was tested by sequencing.Results: DNA of bacterial pathogens which showed different migration distances on the gel werecombined and used as a reference panel. This bacterial ladder consisted of eleven different bacterialspecies including Bacteroides sp., S. aureus, Acineto bacter sp., P. aeruginosa, Streptococcus Group Aand Group B sp., E. faecalis, Providencia sp., Veillonella sp., E .coli and Enterobacter sp. Accordingto the reference panel, Pseudomonas species were abundant. Further the results were confirmed bysequencing.Conclusion: Reference marker allows comparative analysis of DGGE patterns and can be used as atool for presumptive identification of polymicrobial microbiota in chronic wound infections

Three dimensional ink-jet printing of biomaterials using ionic liquids and co-solvents

1-Ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) and 1-butyl-3-methylimidazolium acetate ([C4C1Im][OAc]) have been used as solvents for the dissolution and ink-jet printing of cellulose from 1.0 to 4.8 wt%, mixed with the co-solvents 1-butanol and DMSO. 1-Butanol and DMSO were used as rheological modifiers to ensure consistent printing, with DMSO in the range of 41–47 wt% producing samples within the printable range of a DIMATIX print-head used (printability parameter < 10) at 55 °C, whilst maintaining cellulose solubility. Regeneration of cellulose from printed samples using water was demonstrated, with the resulting structural changes to the cellulose sample assessed by scanning electron microscopy (SEM) and white light interferometry (WLI). These results indicate the potential of biorenewable materials to be used in the 3D additive manufacture process to generate single-component and composite materials

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty