Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Serum biomarkers of neuroinflammation and blood-brain barrier leakage in amyotrophic lateral sclerosis(BioMed Central Ltd, 2022-12) Cao MC; Cawston EE; Chen G; Brooks C; Douwes J; McLean D; Graham ES; Dragunow M; Scotter ELAmyotrophic lateral sclerosis (ALS) is an incurable and rapidly progressive neurological disorder. Biomarkers are critical to understanding disease causation, monitoring disease progression and assessing the efficacy of treatments. However, robust peripheral biomarkers are yet to be identified. Neuroinflammation and breakdown of the blood-brain barrier (BBB) are common to familial and sporadic ALS and may produce a unique biomarker signature in peripheral blood. Using cytometric bead array (n = 15 participants per group (ALS or control)) and proteome profiling (n = 6 participants per group (ALS or control)), we assessed a total of 106 serum cytokines, growth factors, and BBB breakdown markers in the serum of control and ALS participants. Further, primary human brain pericytes, which maintain the BBB, were used as a biosensor of inflammation following pre-treatment with ALS serum. Principal components analysis of all proteome profile data showed no clustering of control or ALS sera, and no individual serum proteins met the threshold for statistical difference between ALS and controls (adjusted P values). However, the 20 most changed proteins between control and ALS sera showed a medium effect size (Cohen's d = 0.67) and cluster analysis of their levels together identified three sample subsets; control-only, mixed control-ALS, and ALS-only. These 20 proteins were predominantly pro-angiogenic and growth factors, including fractalkine, BDNF, EGF, PDGF, Dkk-1, MIF and angiopoietin-2. S100β, a protein highly concentrated in glial cells and therefore a marker of BBB leakage when found in blood, was unchanged in ALS serum, suggesting that serum protein profiles were reflective of peripheral rather than CNS biofluids. Finally, primary human brain pericytes remained proliferative and their secretome was unchanged by chronic exposure to ALS serum. Our exploratory study suggests that individual serum cytokine levels may not be robust biomarkers in small studies of ALS, but that larger studies using multiplexed analysis of pro-angiogenic and growth factors may identify a peripheral signature of ALS pathogenesis.Item Geographic Disparities in Stroke Outcomes and Service Access: A Prospective Observational Study(Wolters Kluwer Health, Inc on behalf of the American Academy of Neurology, 26/07/2022) Thompson SG; Barber PA; Gommans JH; Cadilhac DA; Davis A; Fink JN; Harwood M; Levack W; McNaughton HK; Feigin VL; Abernethy V; Girvan J; Kim J; Denison H; Corbin M; Wilson A; Douwes J; Ranta ABACKGROUND AND OBJECTIVE: International evidence shows that patients treated at non-urban hospitals experience poorer access to key stroke interventions. Evidence whether this results in poorer outcomes is conflicting and generally based on administrative or voluntary registry data. The aim of this study was to use prospective high-quality comprehensive nationwide patient level data to investigate the association between hospital geography and stroke patient outcomes and access to best practice stroke care in New Zealand. METHODS: This is a prospective, multi-centre, nationally representative observational study involving all 28 New Zealand acute stroke hospitals (18 non-urban), and affiliated rehabilitation and community services. Consecutive adults admitted to the hospital with acute stroke between 1 May and 31 October 2018 were captured. Outcomes included functional outcome (modified Rankin Scale (mRS) shift analysis), functional independence (mRS scores 0-2), quality of life (EQ5D-3L), stroke/vascular events, and death at 3, 6, and 12 months and proportion accessing thrombolysis, thrombectomy, stroke units, key investigations, secondary prevention, and inpatient/community rehabilitation. Results were adjusted for age, sex, ethnicity, stroke severity/type, co-morbidities, baseline function, and differences in baseline characteristics. RESULTS: Overall, 2,379 patients were eligible (mean (standard deviation) age 75 (13.7); 51.2% male; 1,430 urban; 949 non-urban). Patients treated at non-urban hospitals were more likely to score in a higher mRS category (greater disability) at three (aOR=1.28, 1.07-1.53), six (aOR=1.33, 1.07-1.65) and twelve months (aOR=1.31, 1.06-1.62) and were more likely to have died (aOR=1.57, 1.17-2.12) or experienced recurrent stroke and vascular events at 12 months (aOR=1.94, 1.14-3.29 and aOR=1.65, 1.09-2.52). Fewer non-urban patients received recommended stroke interventions including endovascular thrombectomy (aOR=0.25, 95% confidence interval 0.13-0.49), acute stroke unit care (aOR=0.60, 0.49-0.73), antiplatelet prescriptions (aOR=0.72, 0.58-0.88), ≥60 minutes daily physical therapy (aOR=0.55, 0.40-0.77) and community rehabilitation (aOR=0.69, 0.56-0.84). DISCUSSION: Patients managed at non-urban hospitals experience poorer stroke outcomes and reduced access to key stroke interventions across the entire care continuum. Efforts to improve access to high quality stroke care in non-urban hospitals should be a priority.Item Biologically Active Compounds Present in Tobacco Smoke: Potential Interactions Between Smoking and Mental Health(Frontiers Media SA, 26/04/2022) Hong SW; Teesdale-Spittle P; Page R; Ellenbroek B; Truman PTobacco dependence remains one of the major preventable causes of premature morbidity and mortality worldwide. There are well over 8,000 compounds present in tobacco and tobacco smoke, but we do not know what effect, if any, many of them have on smokers. Major interest has been on nicotine, as well as on toxic and carcinogenic effects and several major and minor components of tobacco smoke responsible for the negative health effects of smoking have been elucidated. Smokers themselves report a variety of positive effects from smoking, including effects on depression, anxiety and mental acuity. Smoking has also been shown to have protective effects in Parkinson's Disease. Are the subjective reports of a positive effect of smoking due to nicotine, of some other components of tobacco smoke, or are they a manifestation of the relief from nicotine withdrawal symptoms that smoking provides? This mini-review summarises what is currently known about the components of tobacco smoke with potential to have positive effects on smokers.Item Evidence of perceived psychosocial stress as a risk factor for stroke in adults: a meta-analysis(BioMed Central, 2015) Booth J; Connelly L; Lawrence M; Chalmers C; Joice S; Becker C; Dougall NAbstract Background : Several studies suggest that perceived psychosocial stress is associated with increased risk of stroke; however results are inconsistent with regard to definitions and measurement of perceived stress, features of individual study design, study conduct and conclusions drawn and no meta-analysis has yet been published. We performed a systematic review and meta-analysis of studies assessing association between perceived psychosocial stress and risk of stroke in adults.The results of the meta-analysis are presented. Methods: Systematic searches of MEDLINE, EMBASE, CINAHL, PsycInfo, and Cochrane Database of Systematic Reviews were undertaken between 1980 and June 2014. Data extraction and quality appraisal was performed by two independent reviewers. Hazard ratios (HR) and odds ratios (OR) were pooled where appropriate. Results: 14 studies were included in the meta-analysis, 10 prospective cohort, 4 case–control design. Overall pooled adjusted effect estimate for risk of total stroke in subjects exposed to general or work stress or to stressful life events was 1.33 (95 % confidence interval [CI], 1.17, 1.50; P < 0.00001). Sub-group analyses showed perceived psychosocial stress to be associated with increased risk of fatal stroke (HR 1.45 95 % CI, 1.19,1.78; P = 0.0002), total ischaemic stroke (HR 1.40 95 % CI, 1.00,1.97; P = 0.05) and total haemorrhagic stroke (HR 1.73 95 % CI, 1.33,2.25; P > 0.0001).A sex difference was noted with higher stroke risk identified for women (HR 1.90 95 % CI, 1.4, 2.56: P < 0.0001) compared to men (HR 1.24 95 % CI, 1.12, 1.36; P < 0.0001). Conclusions: Current evidence indicates that perceived psychosocial stress is independently associated with increased risk of stroke.Item Increased Abundance of Nuclear HDAC4 Impairs Neuronal Development and Long-Term Memory(Frontiers Media, 30/03/2021) Fitzsimons H; Main P; Wheeler D; Tan WJDysregulation of the histone deacetylase HDAC4 is associated with both neurodevelopmental and neurodegenerative disorders, and a feature common to many of these disorders is impaired cognitive function. HDAC4 shuttles between the nucleus and cytoplasm in both vertebrates and invertebrates and alterations in the amounts of nuclear and/or cytoplasmic HDAC4 have been implicated in these diseases. In Drosophila, HDAC4 also plays a critical role in the regulation of memory, however, the mechanisms through which it acts are unknown. Nuclear and cytoplasmically-restricted HDAC4 mutants were expressed in the Drosophila brain to investigate a mechanistic link between HDAC4 subcellular distribution, transcriptional changes and neuronal dysfunction. Deficits in mushroom body morphogenesis, eye development and long-term memory correlated with increased abundance of nuclear HDAC4 but were associated with minimal transcriptional changes. Although HDAC4 sequesters MEF2 into punctate foci within neuronal nuclei, no alteration in MEF2 activity was observed on overexpression of HDAC4, and knockdown of MEF2 had no impact on long-term memory, indicating that HDAC4 is likely not acting through MEF2. In support of this, mutation of the MEF2 binding site within HDAC4 also had no impact on nuclear HDAC4-induced impairments in long-term memory or eye development. In contrast, the defects in mushroom body morphogenesis were ameliorated by mutation of the MEF2 binding site, as well as by co-expression of MEF2 RNAi, thus nuclear HDAC4 acts through MEF2 to disrupt mushroom body development. These data provide insight into the mechanisms through which dysregulation of HDAC4 subcellular distribution impairs neurological function and provides new avenues for further investigation.Item Comparison of electroencephalographic changes in response to acute electrical and thermal stimuli with the tail flick and hot plate test in rats administered with opiorphin(BioMed Central Ltd, 19/04/2018) Singh P; Kongara K; Harding D; Ward N; Dukkipati VSR; Johnson C; Chambers PBackground The objective of this study was to compare the changes in the electroencephalogram (EEG) in response to noxious stimuli with tail flick and hot plate responses of rats administered opiorphin. Methods Female Sprague -Dawley rats (n = 8 per group) randomly received intravenous (IV) injection of morphine (1 mg/kg,) or opiorphin (2 mg/kg,) or saline (0.5 ml,) in each of the three testing methods (EEG, tail flick and hot plate). Each type of test (n = 24 per test) was conducted in different population of rats on separate occasions. The tail flick and hot plate latencies were recorded until 5 min after test drug administration to conscious rats. The EEG was recorded in anaesthetised rats subjected to noxious thermal and electrical stimuli after test drug administration. At the end of 5 min in each of the testing methods rats were administered naloxone subcutaneously (SC) (1 mg/kg) and the test procedure was repeated. Results There was no significant increase in the median frequency and spectral edge frequency (F50 & F95) of EEG, indicators of nociception, of morphine and opiorphin groups after noxious stimulation. Noxious stimuli caused a significant increase in both F50 and F95 of the saline group. An injection of naloxone significantly increased the F50, thus blocking the action of both opiorphin and morphine. There was a significant increase in the tail flick latency after administration of opiorphin and morphine as compared to the baseline values. Rats of morphine group spent significantly longer on the hot plate when compared to those of the opiorphin and saline groups. There was no significant difference in the hot plate latencies of opiorphin and saline groups. Conclusion The results of this study suggest that the analgesic effect of opiorphin occurs at the spinal level and it is not as effective as morphine at supraspinal level. It may be due to rapid degradation of opiorphin or limited ability of opiorphin to cross the blood brain barrier or a higher dose of opiorphin is required for its action in the brain. Pharmacokinetic/pharmacodynamics studies along with in vivo penetration of opiorphin in the cerebrospinal fluid are required for further evaluation of opiorphin analgesia.
