Characterising the Aboriginal and Torres Strait Islander patient journey after a serious road traffic injury and barriers to access to compensation: a protocol.

INTRODUCTION: Road safety has been a long-enduring policy concern in Australia, with significant financial burden of road trauma and evident socioeconomic disparities. Transport injuries disproportionately impact individuals in remote areas, those in lower socioeconomic situations, and Aboriginal and Torres Strait Islander populations. There is a lack of insight into transport injuries in Aboriginal and Torres Strait Islander communities, absence of Indigenous perspective in published research and limited utilisation of linked data assets to address the inequity. Aim 1 is to determine the breadth, cost and causal factors of serious injury from road traffic crashes in South Australia (SA) and New South Wales (NSW) with a focus on injury prevention. Aim 2 is to identify enablers and barriers to compensation schemes for Aboriginal and Torres Strait Islander patients in SA and NSW. METHODS AND ANALYSIS: This study will be guided by an Aboriginal and Torres Strait Islander Governance Group, applying Knowledge Interface Methodology and Indigenous research principles to ensure Indigenous Data Sovereignty and incorporation of informed perspectives. A mixed-method approach will be undertaken to explore study aims including using big data assets and mapping patient journey. CONCLUSION: The results of this study will provide valuable insights for the development of focused injury prevention strategies and policies tailored to Aboriginal and Torres Strait Islander communities. By addressing the specific needs and challenges faced by these communities, the study aims to enhance road safety outcomes and promote equitable access to healthcare and compensation for affected individuals and their families.

Developing a climate change inequality health impact assessment for health services.

OBJECTIVES: To develop a Climate Change Inequality Health Impact Assessment (CCIHIA) framework for health services; to provide a systematic process for assessing potential unequal health impacts of climate change on vulnerable and marginalised populations and places; to support effective planning to address these impacts; and to develop contextually appropriate local strategies. Type of program: A collaborative interdisciplinary scoping research project involving two universities and two local health districts (LHDs) in New South Wales (NSW) to develop a CCIHIA framework. This work builds upon the health impact assessment (HIA) approach, which systematically assesses proposals' potential health and equity impacts by involving stakeholders in developing responses. METHODS: The project involved four main activities: understanding stakeholder requirements; conceptualising climate change vulnerability; considering the role of health services; and integrating findings into a conceptual framework. RESULTS: Stakeholders identified key functions that should be addressed across the framing, process and utility of the CCIHIA framework. The resulting conceptual framework outlines contexts and social stratification, the differential impacts of climate change (including factors influencing unequal impacts) and the health system's position, and also identifies key potential points of intervention. LESSONS LEARNT: The challenge of addressing the complexity of factors and resulting health impacts is reflected within the CCIHIA framework. While there are many intervention points within this framework for health services to address, many factors influencing unequal impacts are created outside the health sector's direct control. The framework's development process reflected the focus on collaboration and the interdisciplinary nature of climate change response. Ultimately, the CCIHIA framework is an assessment tool and an approach for prioritising inclusive, cross-cutting, multisector working, and problem-solving.

Molecular mechanism of topoisomerase poisoning by the peptide antibiotic albicidin.

The peptide antibiotic albicidin is a DNA topoisomerase inhibitor with low-nanomolar bactericidal activity towards fluoroquinolone-resistant Gram-negative pathogens. However, its mode of action is poorly understood. We determined a 2.6 Å resolution cryoelectron microscopy structure of a ternary complex between Escherichia coli topoisomerase DNA gyrase, a 217 bp double-stranded DNA fragment and albicidin. Albicidin employs a dual binding mechanism where one end of the molecule obstructs the crucial gyrase dimer interface, while the other intercalates between the fragments of cleaved DNA substrate. Thus, albicidin efficiently locks DNA gyrase, preventing it from religating DNA and completing its catalytic cycle. Two additional structures of this trapped state were determined using synthetic albicidin analogues that demonstrate improved solubility, and activity against a range of gyrase variants and E. coli topoisomerase IV. The extraordinary promiscuity of the DNA-intercalating region of albicidins and their excellent performance against fluoroquinolone-resistant bacteria holds great promise for the development of last-resort antibiotics.

The Prognostic Value of Plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) in Patients with Gastrointestinal Stromal Tumor.

BACKGROUND: This study investigates the prognostic value of plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) concentrations in patients with Gastrointestinal Stromal Tumor (GIST). METHODS: Patients with GIST were included (n = 157) from the two Danish sarcoma centers, independent of disease- and treatment status. The patients were divided into three subgroups; 1: patients with localized disease who underwent radical surgery; 2: patients with local, locally advanced, or metastatic disease; and 3: patients without measurable disease who had undergone radical surgery. Sensitive electrochemiluminescence immune-assays were used to determine PD-1 and PD-L1 concentration in plasma samples. The primary endpoint was the PFS. RESULTS: No patients progressed in group 1 (n = 15), 34 progressed in group 2 (n = 122), and three progressed in group 3 (n = 20). Significantly higher plasma concentrations of PD-1 (p = 0.0023) and PD-L1 (0.012) were found in patients in group 2 compared to PD-1/PD-L1 levels in postoperative plasma samples from patient group 1. Patients with active GIST having a plasma concentration of PD-L1 above the cutoff (225 pg/mL) had a significantly poorer prognosis compared to patients with plasma PD-L1 concentration below the cutoff. CONCLUSIONS: Plasma PD-L1 shows potential as a prognostic biomarker in patients with GIST and should be further evaluated.

Comparative analysis of off-road vehicle crashes in children: motorcycles versus quad bikes.

OBJECTIVE: To characterise and compare off-road motorcycle and quad bike crashes in children in New South Wales (NSW), Australia. METHODS: A retrospective, cross-sectional study was performed of children aged 0-16 years, admitted to hospitals in NSW, from 2001 to 2018 following an injury sustained in an off-road motorcycle or quad bike crash, using linked hospital admissions, mortality and census data.Motorcycle and quad bike injuries were compared regarding: demographics; incidence; body region injured and type of injury; injury severity based on the survival risk ratio; length of stay and mortality. RESULTS: There were 6624 crashes resulting in hospitalisation; 5156 involving motorcycles (77.8%) and 1468 involving quad bikes (22.2%). There were 10 fatalities (6 from motorcycles and 4 from quad bikes). The rates of injury declined over the study period for motorcycles, but not for quad bikes.Motorcycle riders were more likely than quad bike riders to have lower limb injuries (OR 1.49, p<0.001) but less likely to have head/neck (OR 0.616, p<0.001), abdominal (OR 0.778, p=0.007) and thoracic (OR 0.745, p=0.003) injuries. Quad bike crashes resulted in higher injury severity (mean International Classification Injury Severity Score 0.975 vs 0.977, p=0.03) and longer hospital stay (mean 2.42 days vs 2.09 days, p=0.01). CONCLUSIONS: There are significant differences between quad bike and motorcycle crashes in injury type and affected body region. While quad bike injuries in children were more severe, there were almost four times more hospitalisations from motorcycles overall. The overall larger burden of motorcycle crashes suggests a greater focus of injury prevention countermeasures for two-wheeled riders is needed.

Detailed structure-function correlations of Bacillus subtilis acetolactate synthase.

Isobutanol is deemed to be a next-generation biofuel and a renewable platform chemical.1 Non-natural biosynthetic pathways for isobutanol production have been implemented in cell-based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst.2-6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg(2+) as cofactors. AlsS also catalyzes the conversion of 2-ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP-dependent enzymes. To unravel catalytically relevant structure-function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg(2+) and in a transition state with a 2-lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.

Entrapment of DNA in an intersubunit tunnel system of a single-stranded DNA-binding protein.

Instead of a classical single-stranded deoxyribonuleic acid (DNA)-binding protein (SSB), some hyperthermophilic crenarchaea harbor a non-canonical SSB termed ThermoDBP. Two related but poorly characterized groups of proteins, which share the ThermoDBP N-terminal DNA-binding domain, have a broader phylogenetic distribution and co-exist with ThermoDBPs and/or other SSBs. We have investigated the nucleic acid binding properties and crystal structures of representatives of these groups of ThermoDBP-related proteins (ThermoDBP-RPs) 1 and 2. ThermoDBP-RP 1 and 2 oligomerize by different mechanisms and only ThermoDBP-RP2 exhibits strong single-stranded DNA affinity in vitro. A crystal structure of ThermoDBP-RP2 in complex with DNA reveals how the NTD common to ThermoDBPs and ThermoDBP-RPs can contact the nucleic acid in a manner that allows a symmetric homotetrameric protein complex to bind single-stranded DNA molecules asymmetrically. While single-stranded DNA wraps around the surface or binds along channels of previously investigated SSBs, it traverses an internal, intersubunit tunnel system of a ThermoDBP-RP2 tetramer. Our results indicate that some archaea have acquired special SSBs for genome maintenance in particularly challenging environments.

Structural and biochemical studies of SLIP1-SLBP identify DBP5 and eIF3g as SLIP1-binding proteins.

In metazoans, replication-dependent histone mRNAs end in a stem-loop structure instead of the poly(A) tail characteristic of all other mature mRNAs. This specialized 3' end is bound by stem-loop binding protein (SLBP), a protein that participates in the nuclear export and translation of histone mRNAs. The translational activity of SLBP is mediated by interaction with SLIP1, a middle domain of initiation factor 4G (MIF4G)-like protein that connects to translation initiation. We determined the 2.5 Å resolution crystal structure of zebrafish SLIP1 bound to the translation-activation domain of SLBP and identified the determinants of the recognition. We discovered a SLIP1-binding motif (SBM) in two additional proteins: the translation initiation factor eIF3g and the mRNA-export factor DBP5. We confirmed the binding of SLIP1 to DBP5 and eIF3g by pull-down assays and determined the 3.25 Å resolution structure of SLIP1 bound to the DBP5 SBM. The SBM-binding and homodimerization residues of SLIP1 are conserved in the MIF4G domain of CBP80/20-dependent translation initiation factor (CTIF). The results suggest how the SLIP1 homodimer or a SLIP1-CTIF heterodimer can function as platforms to bridge SLBP with SBM-containing proteins involved in different steps of mRNA metabolism.

The mRNA export protein DBP5 binds RNA and the cytoplasmic nucleoporin NUP214 in a mutually exclusive manner.

The DEAD-box protein DBP5 is essential for mRNA export in both yeast and humans. It binds RNA and is concentrated and locally activated at the cytoplasmic side of the nuclear pore complex. We have determined the crystal structures of human DBP5 bound to RNA and AMPPNP, and bound to the cytoplasmic nucleoporin NUP214. The structures reveal that binding of DBP5 to nucleic acid and to NUP214 is mutually exclusive. Using in vitro assays, we demonstrate that NUP214 decreases both the RNA binding and ATPase activities of DBP5. The interactions are mediated by conserved residues, implying a conserved recognition mechanism. These results suggest a framework for the consecutive steps leading to the release of mRNA at the final stages of nuclear export. More generally, they provide a paradigm for how binding of regulators can specifically inhibit DEAD-box proteins.

Conjugated bile acid hydrolase is a tetrameric N-terminal thiol hydrolase with specific recognition of its cholyl but not of its tauryl product.

Bacterial bile salt hydrolases catalyze the degradation of conjugated bile acids in the mammalian gut. The crystal structures of conjugated bile acid hydrolase (CBAH) from Clostridium perfringens as apoenzyme and in complex with taurodeoxycholate that was hydrolyzed to the reaction products taurine and deoxycholate are described here at 2.1 and 1.7 A resolution, respectively. The crystal structures reveal close relationship between CBAH and penicillin V acylase from Bacillus sphaericus. This similarity together with the N-terminal cysteine classifies CBAH as a member of the N-terminal nucleophile (Ntn) hydrolase superfamily. Both crystal structures show an identical homotetrameric organization with dihedral (D(2) or 222) point group symmetry. The structure analysis of C. perfringens CBAH identifies critical residues in catalysis, substrate recognition, and tetramer formation which may serve in further biochemical characterization of bile acid hydrolases.

Structure of human chitotriosidase. Implications for specific inhibitor design and function of mammalian chitinase-like lectins.

Chitin hydrolases have been identified in a variety of organisms ranging from bacteria to eukaryotes. They have been proposed to be possible targets for the design of novel chemotherapeutics against human pathogens such as fungi and protozoan parasites as mammals were not thought to possess chitin-processing enzymes. Recently, a human chitotriosidase was described as a marker for Gaucher disease with plasma levels of the enzyme elevated up to 2 orders of magnitude. The chitotriosidase was shown to be active against colloidal chitin and is inhibited by the family 18 chitinase inhibitor allosamidin. Here, the crystal structure of the human chitotriosidase and complexes with a chitooligosaccharide and allosamidin are described. The structures reveal an elongated active site cleft, compatible with the binding of long chitin polymers, and explain the inactivation of the enzyme through an inherited genetic deficiency. Comparison with YM1 and HCgp-39 shows how the chitinase has evolved into these mammalian lectins by the mutation of key residues in the active site, tuning the substrate binding specificity. The soaking experiments with allosamidin and chitooligosaccharides give insight into ligand binding properties and allow the evaluation of differential binding and design of species-selective chitinase inhibitors.