A major Streptococcus pneumoniae pathogenic factor is the cholesterol-dependent cytolysin pneumolysin, binding membrane cholesterol and producing permanent lytic or transient pores. During brain infections, vascular damage with variable ischemia occurs. The role of ischemia on pneumolysin’s pore-forming capacity remains unknown. In acute brain slice cultures and primary cultured glia, we studied acute toxin lysis (via propidium iodide staining and LDH release) and transient pore formation (by analyzing increases in the intracellular calcium). We analyzed normal peripheral tissue glucose conditions (80 mg%), normal brain glucose levels (20 mg%), and brain hypoglycemic conditions (3 mg%), in combinations either with normoxia (8% oxygen) or hypoxia (2% oxygen). At 80 mg% glucose, hypoxia enhanced cytolysis via pneumolysin. At 20 mg% glucose, hypoxia did not affect cell lysis, but impaired calcium restoration after non-lytic pore formation. Only at 3 mg% glucose, during normoxia, did pneumolysin produce stronger lysis. In hypoglycemic (3 mg% glucose) conditions, pneumolysin caused a milder calcium increase, but restoration was missing. Microglia bound more pneumolysin than astrocytes and demonstrated generally stronger calcium elevation. Thus, our work demonstrated that the toxin pore-forming capacity in cells continuously diminishes when oxygen is reduced, overlapping with a continuously reduced ability of cells to maintain homeostasis of the calcium influx once oxygen and glucose are reduced.

Objective A workers’ compensation claim may have significant negative impacts on an injured worker’s wellbeing. Wellbeing provides a good global measure of potential effects of a claim on an individual, and is important for contemporary economic modelling. The purpose of this study was to synthesize knowledge about the wellbeing of injured workers after the finalization of a workers’ compensation claim and identify gaps in the current literature. Methods A systematic scoping review was conducted. Results 71 full-text articles were screened for inclusion, with 32 articles eligible for this review. None of the included articles evaluated overall wellbeing. Included articles did evaluate a variety of constructs inherent in wellbeing. Injured workers were generally disadvantaged in some manner following claim finalization. The literature recommends a focus on reducing negative impacts on injured workers after finalization of a compensation claim, with a need for regulatory bodies to review policy in this area. Conclusion There appears to be potential for ongoing burden for individuals, employers, and society after finalization of a workers’ compensation claim. A gap in knowledge exists regarding the specific evaluation of wellbeing of injured workers following finalization of a workers’ compensation claim.

Background Complex regional pain syndrome (CRPS) can be a debilitating pain condition with enduring physical, psychological and social impacts. CRPS is often poorly understood by healthcare professionals and management needs to be tailored to each individual's presentation. People with lived experience express difficulty in accessing reliable and meaningful information about the condition. This study aimed to co-create a trustworthy infographic to share information about the lived experience of CRPS. Methods We adopted a seven-phase, iterative, participatory methodology to co-create the infographic. Potential infographic content was obtained from qualitative work investigating the lived experience of CRPS. Online consumer engagement (people with doctor diagnosed CRPS/their family, n=20) was used to prioritise content to be included in the infographic and then potential designs were sourced. The research team narrowed the selections down to two designs which were presented to consumers online for final selection (n=25) and refinement (n=34). Results An infographic for understanding the lived experience of CRPS was completed using participatory design, providing a resource aligned to the needs of people with this condition. Using the Patient Education Materials Assessment Tool, the final infographic rated highly for understandability (92%) and participants indicated significant willingness to share this infographic with others (93%). Conclusion A process of participatory design was an effective and efficient process for translation of evidence gathered from qualitative research into a trustworthy resource for people with CRPS and their support people.

IntroductionStreptococcus pneumoniae (pneumococcus) meningitis is a serious disease with substantial lethality and long-term disability in survivors. Loss of synaptic staining in the superficial layers of the neocortex in rodent models and in humans, and pneumolysin (a major pneumococcal toxin)-dependent dendritic spine collapse in brain slices have been described. It remains unclear how deep in the neocortex more discrete changes are present, how soon after disease onset these changes occur, and whether other properties of dendrites are also affected.MethodsUsing a mouse model of pneumococcal meningitis, we studied changes in the neocortex shortly (3–6 h) after the onset of clinical symptoms via modified Golgi-Cox silver staining.ResultsDendritic changes were present in areas with otherwise unchanged cell numbers and no signs of necrosis or other apparent neuronal pathology. Mature dendritic spines were reduced in the pyramidal neurons running through layers 1–5. Additionally, spine morphology changes (swelling, spine neck distortion), were also observed in the deeper layers 4 and 5 of the neocortex. Immature spines (filopodia) remained unchanged between groups, as well as the dendritic arborization of the analyzed neurons. In a third of the animals with meningitis, massive mechanical distortion of the primary dendrites of most of the pyramidal neurons through layers 1–5 was observed. This distortion was reproduced in acute brain slices after exposure to pneumolysin-containing bacterial lysates (S. pneumoniae D39 strain), but not to lysates of pneumolysin-deficient bacteria, which we explain by the tissue remodeling effect of the toxin. Experimental mechanical dendrite distortion in primary neural cultures demonstrated diminished FRAP diffusion of neuronally-expressed enhanced green fluorescent protein (eGFP), indicative of disturbed dendritic diffusion.DiscussionOur work extends earlier knowledge of synaptic loss in the superficial cortical layers during meningitis to deeper layers. These changes occurred surprisingly early in the course of the disease, substantially limiting the effective therapeutic window. Methodologically, we demonstrate that the dendritic spine collapse readout is a highly reliable and early marker of neural damage in pneumococcal meningitis models, allowing for reduction of the total number of animals used per a group due to much lower variation among animals.

Fear is a significant factor affecting successful return to sport following an anterior cruciate ligament (ACL) injury. However, there is a lack of understanding of the emotional drivers of fear and how fear beliefs are formed. This study qualitatively explored the contextual and emotional underpinnings of fear and how these beliefs were formed, with reference to the Common-Sense Model of Self-Regulation. Face-to-face online interviews were conducted with ACL-injured participants (n = 18, 72% female) with a mean age of 28 years (range 18–50 years). Participants were either 1 year post ACL reconstruction surgery (n = 16) or at least 1 year post injury without surgery (n = 2) and scored above average on a modified Tampa Scale of Kinesiophobia. Four participants were playing state-level sport or higher. Five themes emerged describing factors contributing to fear: ‘External messages’, ‘Difficulty of the ACL rehabilitation journey’, ‘Threat to identity and independence’, ‘Socioeconomic factors’, and ‘Ongoing psychological barriers’. A sixth theme, ‘Positive coping strategies’, provided insight into influences that could reduce fear and resolve negative behaviors. This study identified a broad range of contextual biopsychosocial factors which contribute to fear, supporting the notion that ACL injuries should not be treated through a purely physical lens. Furthermore, aligning the themes to the common-sense model provided a conceptual framework conveying the inter-related, emergent nature of the identified themes. The framework provides clinicians with a means to understanding fear after an ACL injury. This could guide assessment and patient education.

Introduction: Many people who have undergone Anterior Cruciate Ligament (ACL)-reconstruction do not return to their pre-injury level, with nonphysical factors recognized as barriers to recovery. Fear of movement has been linked to body schema distortions, and interventions directed at the body schema have shown potential to improve function. Objective: 1) Describe participants' ability to perform a visual imagery intervention (Body Scan); 2) investigate knee perception differences; 3) investigate if Body Scan led to improvements in perceptual differences; and 4) determine if some individuals improved in functional measures following the intervention. Methods: A single-arm intervention study was undertaken in people >12-month post ACL-reconstruction (n = 30). Body Scan was delivered using a standardized script developed for this study. Participants were assessed regarding their capacity to perform the Body Scan, perceptual differences between the knees and how perception changed following the intervention. Functional measures (vertical hop, triple hop, mSEBT, quadriceps strength, and hamstring strength) were taken. Results: 96.7% were able to perform a Body Scan, with 93.1% demonstrating a difference in perception between the knees. Of participants with perceptual differences, 92.5% demonstrated improvement in perception following the intervention. Ten participants had a clinically significant improvement in a functional measure following the intervention. Conclusion: Most participants could perform Body Scanning. The majority perceived perceptual differences between operated and non-operated knees, and reported more symmetric perception following the intervention. One-third of participants also showed improvements in a functional performance measure. Results suggest this intervention may be a helpful adjunct to rehabilitation post ACL-reconstruction, with further research warranted.

Fear is a factor contributing to poor return to sport after an anterior cruciate (ACL) injury, however the identification and assessment of fear is challenging. To improve understanding of fear, this study qualitatively and quantitatively assessed responses to videos depicting threat to knee stability in people who had experienced an ACL injury. ACL-injured participants who had above average fear on the Tampa Scale of Kinesiophobia and were at least 1-year post-injury/surgery were eligible. Participants were shown four videos depicting sequentially increasing threat to their knee stability (running, cut-and-pivot, feigned knee injury during cut-and-pivot, series of traumatic knee injuries). Qualitative interviews explored participants feeling related to viewing the videos. Participants quantitatively self-rated fear and distress in response to each video. Seventeen participants were included in this study (71% female, with an average time since last ACL injury of 5 ½ years). Five themes were identified: (1) Evoked physiological responses, (2) Deeper contextualisation of the meaning of an ACL injury influencing bodily confidence, (3) Recall of psychological difficulties, (4) Negative implications of a re-injury, and (5) Change to athletic identity. Quantitatively, direct proportionality was noticed between threat level and reported fear and distress. Specifically, participants reported increasing levels of fear and distress as the videos progressed in threat level, with the largest increase seen between a cut-and-pivot movement to a feigned injury during a cut and pivot. The results support the notion that in addition to being a physical injury, an ACL injury has more complex neurophysiological, psychological, and social characteristics which should be considered in management. Using video exposure in the clinic may assist identification of underlying psychological barriers to recovery following an ACL injury, facilitating person-centred care.

Streptococcus pneumoniae (the pneumococcus) is a major human pathogen causing invasive disease, including community-acquired bacteraemia, and remains a leading cause of global mortality. Understanding the role of phagocytes in killing bacteria is still limited, especially in vivo. In this study, we established a zebrafish model to study the interaction between intravenously administered pneumococci and professional phagocytes such as macrophages and neutrophils, to unravel bacterial killing mechanisms employed by these immune cells. Our model confirmed the key role of polysaccharide capsule in promoting pneumococcal virulence through inhibition of phagocytosis. Conversely, we show pneumococci lacking a capsule are rapidly internalised by macrophages. Low doses of encapsulated S. pneumoniae cause near 100% mortality within 48 hours postinfection (hpi), while 50 times higher doses of unencapsulated pneumococci are easily cleared. Time course analysis of in vivo bacterial numbers reveals that while encapsulated pneumococcus proliferates to levels exceeding 105 CFU at the time of host death, unencapsulated bacteria are unable to grow and are cleared within 20 hpi. Using genetically induced macrophage depletion, we confirmed an essential role for macrophages in bacterial clearance. Additionally, we show that upon phagocytosis by macrophages, phagosomes undergo rapid acidification. Genetic and chemical inhibition of vacuolar ATPase (v-ATPase) prevents intracellular bacterial killing and induces host death indicating a key role of phagosomal acidification in immunity to invading pneumococci. We also show that our model can be used to study the efficacy of antimicrobials against pneumococci in vivo. Collectively, our data confirm that larval zebrafish can be used to dissect killing mechanisms during pneumococcal infection in vivo and highlight key roles for phagosomal acidification in macrophages for pathogen clearance.

In pneumococcal meningitis, bacterial growth in the cerebrospinal fluid results in lysis, the release of toxic factors, and subsequent neuroinflammation. Exposure of primary murine glia to Streptococcus pneumoniae lysates leads to strong proinflammatory cytokine and chemokine production, blocked by inhibition of the intracellular innate receptor Nod1. Lysates enhance dynamin-dependent endocytosis, and dynamin inhibition reduces neuroinflammation, blocking ligand internalization. Here we identify the cholesterol-dependent cytolysin pneumolysin as a pro-endocytotic factor in lysates, its elimination reduces their proinflammatory effect. Only pore-competent pneumolysin enhances endocytosis in a dynamin-, phosphatidylinositol-3-kinase- and potassium-dependent manner. Endocytic enhancement is limited to toxin-exposed parts of the membrane, the effect is rapid and pneumolysin permanently alters membrane dynamics. In a murine model of pneumococcal meningitis, mice treated with chlorpromazine, a neuroleptic with a complementary endocytosis inhibitory effect show reduced neuroinflammation. Thus, the dynamin-dependent endocytosis emerges as a factor in pneumococcal neuroinflammation, and its enhancement by a cytolysin represents a proinflammatory control mechanism.

Objectives Complex regional pain syndrome (CRPS) is a persistent pain condition which is often misunderstood and poorly managed. Qualitative studies are needed to explore the lived experience of the condition and to better understand patient perspectives on their management experiences and needs. The aim of this study was to explore the lived experience of CRPS in Australia, including exploration of their perceptions of care and advice received from healthcare professionals. Methods A qualitative study with individual in-depth semi-structured, face-to-face interviews was performed (n=15, 80% female, average time elapsed since diagnosis 3.8 years). Qualitative data were analysed using an inductive thematic analysis approach. Results Four main themes with associated subthemes were identified, representing the participants’ journey: (1) Life Changing Impact of CRPS (Subthemes: Impact on self, Impact on others); (2) Variable Experiences of Care (Subthemes: Helpful experiences of care, Unhelpful experiences of care); (3) Making Sense of CRPS (Subthemes: Knowledge and understanding, Dealing with unpredictability); and (4) Perceptions on Lessons Learned from Living with CRPS (Subthemes: Acceptance was an important part of the journey, Trial and error was necessary to find an individual way forward, Coping strategies). Conclusions The themes identified align to and expand on prior qualitative research findings in people with CRPS. It highlights the challenges people face related to their personal self, their close relationships and their social and work roles. It highlights the difficulties these people have in finding reliable, trust-worthy information. These findings suggest that healthcare professionals may benefit from education about how to better support people with CRPS, including helping people to navigate to the right care. Engaging people with CRPS in the development of educational resources should be a future research goal. It is recommended that patient perspectives are incorporated into the development of care pathways for CRPS.

Specialist physiotherapy services can fill a gap in the management of pain disorders in primary care. Fatima has persistent musculoskeletal pain, not responding to first-line guideline-based management. Despite normal radiology, specialist medical review is requested. Although waiting considerable time for the appointment (partly caused by the backlog of patients like her), Mary develops secondary mental health issues. The usual stepped-care approach is failing her. Specialist physiotherapist review is requested, providing expert-level management suggestions to address complexity in her presentation. The specialist physiotherapist works collaboratively with her treating physiotherapist to achieve positive outcomes for Fatima. Specialist physiotherapy services are an under-recognised value-added step between the GP and medical specialist. Increased utilisation of the skills and competencies of specialist physiotherapists can positively contribute to the health of Australians who suffer the burden of complex/persistent musculoskeletal pain complaints.

Apoptosis is an indispensable mechanism for eliminating infected cells and activation of executioner caspases is considered to be a point of no return. Streptococcus pneumoniae, the most common bacterial pathogen causing community-acquired pneumonia, induces apoptosis via its pore-forming toxin pneumolysin, leading to rapid influxes of mitochondrial calcium [Ca2+](m) as well as fragmentation, and loss of motility and membrane potential, which is accompanied by caspase-3/7 activation. Using machine-learning and quantitative live-cell microscopy, we identified a significant number of alveolar epithelial cells surviving such executioner caspase activation after pneumolysin attack. Precise single-cell analysis revealed the [Ca2+](m) amplitude and efflux rate as decisive parameters for survival and death, which was verified by pharmacological inhibition of [Ca2+](m) efflux shifting the surviving cells towards the dying fraction. Taken together, we identified the regulation of [Ca2+](m) as critical for controlling the cellular fate under pneumolysin attack, which might be useful for therapeutic intervention during pneumococcal infection.

Microvesicles (MVs) are cell-derived extracellular vesicles that have emerged as markers and mediators of acute lung injury (ALI). One of the most common pathogens in pneumonia-induced ALI is Streptococcus pneumoniae (Spn), but the role of MVs during Spn lung infection is largely unknown. In the first line of defense against Spn and its major virulence factor, pneumolysin (PLY), are the alveolar epithelial cells (AEC). In this study, we aim to characterize MVs shed from PLY-stimulated AEC and explore their contribution in mediating crosstalk with neutrophils. Using in vitro cell and ex vivo (human lung tissue) models, we demonstrated that Spn in a PLY-dependent manner stimulates AEC to release increased numbers of MVs. Spn infected mice also had higher levels of epithelial-derived MVs in their alveolar compartment compared to control. Furthermore, MVs released from PLY-stimulated AEC contain mitochondrial content and can be taken up by neutrophils. These MVs then suppress the ability of neutrophils to produce reactive oxygen species, a critical host-defense mechanism. Taken together, our results demonstrate that AEC in response to pneumococcal PLY release MVs that carry mitochondrial cargo and suggest that these MVs regulate innate immune responses during lung injury.

Pneumolysin (PLY) is a pore-forming toxin of Streptococcus pneumoniae that contributes substantially to the inflammatory processes underlying pneumococcal pneumonia and lung injury. Host responses against S. pneumoniae are regulated in part by neutrophils and platelets, both individually and in cooperative interaction. Previous studies have shown that PLY can target both neutrophils and platelets, however, the mechanisms by which PLY directly affects these cells and alters their interactions are not completely understood. In this study, we characterize the effects of PLY on neutrophils and platelets and explore the mechanisms by which PLY may induce neutrophil–platelet interactions. In vitro studies demonstrated that PLY causes the formation of neutrophil extracellular traps (NETs) and the release of extracellular vesicles (EVs) from both human and murine neutrophils. In vivo, neutrophil EV (nEV) levels were increased in mice infected with S. pneumoniae. In platelets, treatment with PLY induced the cell surface expression of P-selectin (CD62P) and binding to annexin V and caused a significant release of platelet EVs (pl-EVs). Moreover, PLY-induced nEVs but not NETs promoted platelet activation. The pretreatment of nEVs with proteinase K inhibited platelet activation, indicating that the surface proteins of nEVs play a role in this process. Our findings demonstrate that PLY activates neutrophils and platelets to release EVs and support an important role for neutrophil EVs in modulating platelet functions in pneumococcal infections.

A substantial evidence-practice gap exists between healthcare professionals learning about the biopsychosocial model of pain and adopting this model in clinical practice. This review aimed to explore the barriers and enablers that influence the application of a biopsychosocial approach to musculoskeletal pain in practice, from the clinicians' perspective. Qualitative evidence synthesis was used. Four electronic databases (CINAHL, EMBASE, MEDLINE, and PsycINFO) were searched. Primary qualitative studies were included if they investigated the experiences of primary healthcare professionals using a biopsychosocial model of musculoskeletal pain care in outpatient settings or their perceptions towards biopsychosocial-oriented clinical practice guidelines. After screening 6571 abstracts, 77 full-text articles were retrieved. Twenty-five studies met the eligibility criteria, reporting the experiences of 413 healthcare professionals (including general practitioners, physiotherapists, and others) spanning 11 countries. Three metathemes were identified that impact the adoption of the biopsychosocial model across the whole of health: (1) at the microlevel, healthcare professionals' personal factors, knowledge and skills, and their misconceptions of clinical practice guidelines, perception of patients' factors, and time; (2) at the mesolevel, clinical practice guideline formulation, community factors, funding models, health service provision, resourcing issues, and workforce training issues; and (3) at the macrolevel, health policy, organizational, and social factors. Synthesized data revealed multilevel (whole-of-health) barriers and enablers to health professionals adopting a biopsychosocial model of pain into practice. Awareness of these multilevel factors may help inform preimplementation preparedness and support more effective implementation of the biopsychosocial model of musculoskeletal pain into clinical practice.

Objective: The reasons for soft failure after cochlear implantation require investigation. This study proposes a method to study and characterize the tissue response to the array in a case of soft failure in a person undergoing reimplantation. Case: The woman in her 50s, with an underlying autoimmune condition, received a cochlear implant using hearing preservation technique after developing profound hearing loss more than 2 kHz with a moderate loss of less than 500 Hz over a 10-year period. The case was identified as a soft failure due to deteriorating performance, discomfort, and migration over the 10 months after implantation. Impedance telemetry, speech perception measures, and audiometric thresholds are described. At explantation there was evidence of fibrosis. Intervention(s): To use histology and immunohistochemistry to determine the cellular response of the tissue associated with the electrode array at time of explantation. Main Outcome Measure(s): Identification of the cell types, regional variations, and inflammatory marker expression in the fibrotic tissue associated with the array. Results: Neutrophils and eosinophils were identified, along with a variable pattern of collagen deposition. CD68 and CD163-positive macrophages and T cells were variably distributed through the tissue and interleukin-1 beta and vascular endothelial growth factor receptor-2 expression was identified. Conclusions: The expression profile is evidence of active inflammation in the tissue despite the time since implantation. This study is the first to characterize the tissue response to the array in a person undergoing reimplantation, and who can be followed to determine the individual response to arrays. It establishes that the investigation of explanted devices after soft-failure is feasible.