The future of ischemic stroke: flow from prehospital neuroprotection to definitive reperfusion.

Recent advances in ischemic stroke enable a seamless transition of the patient flow from the prehospital setting to definitive reperfusion, without the arbitrary separation of therapeutic phases of ischemia based on time alone. In 2013, the framework to understand and directly address the pathophysiology of cerebral blood flow that determines the timeline or evolution of ischemia in an individual case is given. This continuum of flow and the homeostasis of brain perfusion balanced by collaterals may be captured with serial imaging. Ongoing imaging core laboratory activities permit large-scale measurement of angiographic and tissue biomarkers of ischemia. Prehospital neuroprotection has become a reality and may be combined with revascularization therapies. Recent studies confirm that image-guided thrombolysis may be achieved without restrictive time windows. Baseline imaging patterns may be used to predict response to therapy and serial imaging may discern recanalization and reperfusion. Advanced techniques, such as arterial spin-labeled MRI, may also report hyperperfusion associated with hemorrhagic transformation. Endovascular therapies, including novel stent retriever devices, may augment revascularization and angiographic core laboratories may define optimal reperfusion. Serial evaluation of collaterals and reperfusion may identify definitive reperfusion linked with good clinical outcome rather than imposing arbitrary definitions of effective recanalization. Reperfusion injury and hemorrhagic transformation of various types may be detailed to explain clinical outcomes. Similar approaches may be used in intracranial atherosclerosis where flow, and not the degree of luminal stenosis, is paramount. Fractional flow may now be measured with computational fluid dynamics to identify high-risk lesions that require revascularization to restore the equilibrium of antegrade and collateral perfusion. Serial perfusion imaging of such cases may also illustrate inadequate cerebral blood volume gradients that may be more informative than blood flow delay alone. In sum, the growing understanding of collateral perfusion throughout all stages of ischemic stroke provides a framework for the future of ischemic stroke

Stress, wildlife health and the conservation of a critically endangered marsupial, the woylie

Effective wildlife management requires an understanding of how animals cope physiologically with stress. When stressors are encountered, the hypothalamic pituitary adrenal (HPA) axis is activated releasing glucocorticoids, which can alter immune function and infectious disease dynamics. Investigations have suggested that stress associated immunosuppression and exacerbation of infection (particularly by Trypanosoma spp. of haemoparasite) may play a role in the decline of the woylie (syn. brush-tailed bettong, Bettongia penicillata), a critically endangered marsupial. This thesis aims to investigate the relationship between stress, immune function and parasite infection dynamics in woylies. Woylies were trapped from wild populations, reserves and captivity with faecal and blood samples collected from over 300 individuals. Parallel parasitological and non-invasive endocrine analyses were performed to quantify endoparasites and faecal cortisol metabolites (FCM), end-products of HPA axis activation. I also adapted an assay developed in human infants to assess innate immunity in woylies. The novel results suggest that stress physiology and Trypanosoma infection status influence innate immunity. Collecting longitudinal field data, I identified proximate factors that influenced woylie stress physiology, including season, sex, parasite status and body condition. I also explored woylies’ response to translocation and a major bushfire that unexpectedly occurred at a field site. After translocation, FCM was significantly higher than before or at the time of translocation. However, the variation in FCM was not related to short-term changes in parasite infection dynamics. FCM was not significantly higher immediately after the fire, nor were there corresponding changes in parasite load or body condition compared to the months preceding the fire. I suggest that woylies can maintain homeostasis at least in the period immediately after a fire provided they are managed appropriately. Thus this thesis provides new knowledge on woylie stress physiology and highlights the value of innovative tools to advance woylie conservation as they continue to face stressors in the future

Development of the Lymphoedema Genito-Urinary Cancer Questionnaire

The aim of this study was to develop a patient self-report tool to detect symptoms of genital and lower limb lymphoedema in male survivors of genitourinary cancer. The study incorporated the views of patients and subject specialists (lymphoedema and urology) in the design of a patient questionnaire based on the literature. Views on comprehensiveness, relevance of content, ease of understanding and perceived acceptability to patients were collated. The findings informed the development of the next iteration of the questionnaire. The overall view of participants was that the development and application of such a tool was of great clinical value and the Lymphoedema Genito- Urinary Cancer Questionnaire (LGUCQ) has significant potential for further development as a research tool to inform prevalence of this under-reported condition

Australian cardiac rehabilitation exercise parameter characteristics and perceptions of high-intensity interval training: a cross-sectional survey

Purpose: This study explored current demographics, characteristics, costs, evaluation methods, and outcome measures used in Australian cardiac rehabilitation (CR) programs. It also determined the actual usage and perceptions of high-intensity interval training (HIIT). Methods: A cross-sectional observational web-based survey was distributed to 328 Australian CR programs nationally. Results: A total of 261 programs completed the survey (79.6% response rate). Most Australian CR programs were located in a hospital setting (76%), offered exercise sessions once a week (52%) for 6–8 weeks (49%) at moderate intensity (54%) for 46–60 min (62%), and serviced 101–500 clients per annum (38%). HIIT was reported in only 1% of programs, and 27% of respondents believed that it was safe while 42% of respondents were unsure. Lack of staff (25%), monitoring resources (20%), and staff knowledge (18%) were the most commonly reported barriers to the implementation of HIIT. Overall, Australian CR coordinators are unsure of the cost of exercise sessions. Conclusion: There is variability in CR delivery across Australia. Only half of programs reassess outcome measures postintervention, and cost of exercise sessions is unknown. Although HIIT is recommended in international CR guidelines, it is essentially not being used in Australia and clinicians are unsure as to the safety of HIIT. Lack of resources and staff knowledge were perceived as the biggest barriers to HIIT implementation, and there are inconsistent perceptions of prescreening and monitoring requirements. This study highlights the need to educate health professionals about the benefits and safety of HIIT to improve its usage and patient outcomes

A review of factors influencing the stress response in Australian marsupials

Many Australian marsupials are threatened species. In order to manage in situ and ex situ populations effectively, it is important to understand how marsupials respond to threats. Stress physiology (the study of the response of animals to challenging stimuli), a key approach in conservation physiology, can be used to characterize the physiological response of wildlife to threats. We reviewed the literature on the measurement of glucocorticoids (GCs), endocrine indicators of stress, in order to understand the stress response to conservation-relevant stressors in Australian marsupials and identified 29 studies. These studies employed a range of methods to measure GCs, with faecal glucocorticoid metabolite enzyme immunoassay being the most common method. The main stressors considered in studies of marsupials were capture and handling. To date, the benefits of stress physiology have yet to be harnessed fully in marsupial conservation. Despite a theoretical base dating back to the 1960s, GCs have only been used to understand how 21 of the 142 extant species of Australian marsupial respond to stressors. These studies include merely six of the 60 marsupial species of conservation concern (IUCN Near Threatened to Critically Endangered). Furthermore, the fitness consequences of stress for Australian marsupials are rarely examined. Individual and species differences in the physiological stress response also require further investigation, because significant species-specific variations in GC levels in response to stressors can shed light on why some individuals or species are more vulnerable to stress factors while others appear more resilient. This review summarizes trends, knowledge gaps and future research directions for stress physiology research in Australian marsupial conservation

Stress, wildlife health and the conservation of a critically endangered marsupial, the woylie

When you are stressed, do you find you get sick more easily? And if you’re stressed and sick, do you feel like it takes you longer to recover

High-intensity interval training versus moderate-intensity continuous training within cardiac rehabilitation:a systematic review and meta-analysis

Aerobic capacity has been shown to be inversely proportionate to cardiovascular mortality and morbidity and there is growing evidence that high-intensity interval training (HIIT) appears to be more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness within the cardiac population. Previously published systematic reviews in cardiovascular disease have neither investigated the effect that the number of weeks of intervention has on cardiorespiratory fitness changes, nor have adverse events been collated.We aimed to undertake a systematic review and meta-analysis of randomized controlled trials (RCTs) within the cardiac population that investigated cardiorespiratory fitness changes resulting from HIIT versus MICT and to collate adverse events.A critical narrative synthesis and meta-analysis was conducted after systematically searching relevant databases up to July 2017. We searched for RCTs that compared cardiorespiratory fitness changes resulting from HIIT versus MICT interventions within the cardiac population.Seventeen studies, involving 953 participants (465 for HIIT and 488 for MICT) were included in the analysis. HIIT was significantly superior to MICT in improving cardiorespiratory fitness overall (SMD 0.34 mL/kg/min; 95% confidence interval [CI; 0.2-0.48]; p6-week duration. Programs of 7-12 weeks' duration resulted in the largest improvements in cardiorespiratory fitness for patients with coronary artery disease. HIIT appears to be as safe as MICT for CR participants

Behavioral Changes Without Respiratory Symptoms as a Presenting Sign of COVID-19 Encephalitis.

The clinical presentation, diagnosis, and treatment of coronavirus disease 2019 (COVID-19) encephalitis are still being characterized. Few case reports describing COVID-19 encephalitis are available in the literature. We present a case of COVID-19 encephalitis who presented with behavioral disturbances without respiratory symptoms

Semi-Analytic Techniques for Solving Quasi-Normal Modes

In this chapter, we discuss an approach to obtaining black hole quasi-normal modes known as the asymptotic iteration method, which was initially developed in mathematics as a new way to solve for eigenvalues in differential equations. Furthermore, we demonstrate that the asymptotic iteration method allows one to also solve for the radial quasi-normal modes on a variety of black hole spacetimes for a variety of perturbing fields. A specific example for Dirac fields in a general dimensional Schwarzschild black hole spacetime is given, as well as for spin-3/2 field quasi-normal modes