13 research outputs found

    The Role of Chemokine Receptors CCR6 and CCR7 in the Initiation and Progression of Breast Cancer

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    Breast cancer is one of the most common causes of cancer-related death in women world-wide. Despite many advances in medical research, incidence and mortality rates still remain high. In the last decade, evidence has emerged that links components of the immune system, including various signalling mediators and cell subsets, with regulation and promotion of breast cancer. Among others, the chemokine superfamily has been heavily implicated in the pathobiology of breast cancer due to their ability to induce cellular migration, proliferation and recruitment of supporting cells to the tumour microenvironment upon binding of cognate chemokine receptors. However, the underlying mechanisms and specific details governing the function of chemokines and their receptors in regulating breast cancer development and progression are largely unknown. This study systematically examined the roles of two chemokine receptors, CCR7 and CCR6, in breast cancer initiation and progression. These receptors had previously been shown to induce cellular proliferation and migration of breast cancer cell lines upon stimulation with chemokine ligands and had been implicated in regulation of other malignancies, but in vivo evidence for their roles had not been shown to date. Using the MMTV-PyMT transgenic mouse model for breast cancer, it was found that deletion of CCR7 significantly delayed mammary tumour onset and reduced both the number of primary tumours and extent of distal metastasis to the lungs. It was further found that CCR7 exerted its tumour-promoting function by maintaining populations of stem-like cancer cells. Stimulation of CCR7 in stem cell-enriched cultures induced self-renewal and the loss of this receptor resulted in a significant decrease in tumour-propagating ability of the cells. Furthermore, pharmacological blockade of CCR7 reduced proportions and activity of stem cell-like pools, indicating that this receptor can potentially be targeted therapeutically to eliminate quiescent cancer stem cells. Deletion of CCR6 in the MMTV-PyMT model also significantly delayed tumour onset, reduced the extent of epithelial hyperplasia, and resulted in a decreased incidence of mammary tumours. However, no evidence was found of a role for CCR6 in mammary epithelium, or in maintenance of the cell lineage hierarchy. Upon further investigation, it was discovered that CCR6 was involved in the recruitment of tumour-promoting macrophages to the mammary tumour microenvironment. CCR6 was highly expressed on tumour-associated macrophages, and the loss of CCR6 significantly reduced the numbers of macrophages present in PyMT-driven mammary tumours. Taken together, cumulative data generated throughout the course of this project conclusively demonstrate that CCR7 and CCR6 both have important roles in the development and progression of breast cancer and may therefore have therapeutic utility in targeting both the transformed mammary epithelium and the supporting tumour microenvironment.Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 201

    Prevalence and predictive value of ICD-11 post-traumatic stress disorder and Complex PTSD diagnoses in children and adolescents exposed to a single-event trauma.

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    BACKGROUND: The 11th edition of the International Classification of Diseases (ICD-11) made a number of significant changes to the diagnostic criteria for post-traumatic stress disorder (PTSD). We sought to determine the prevalence and 3-month predictive values of the new ICD-11 PTSD criteria relative to ICD-10 PTSD, in children and adolescents following a single traumatic event. ICD-11 also introduced a diagnosis of Complex PTSD (CPTSD), proposed to typically result from prolonged, chronic exposure to traumatic experiences, although the CPTSD diagnostic criteria do not require a repeated experience of trauma. We therefore explored whether children and adolescents demonstrate ICD-11 CPTSD features following exposure to a single-incident trauma. METHOD: Data were analysed from a prospective cohort study of youth aged 8-17 years who had attended an emergency department following a single trauma. Assessments of PTSD, CPTSD, depressive and anxiety symptoms were performed at two to four weeks (n = 226) and nine weeks (n = 208) post-trauma, allowing us to calculate and compare the prevalence and predictive value of ICD-10 and ICD-11 PTSD criteria, along with CPTSD. Predictive abilities of different diagnostic thresholds were undertaken using positive/negative predictive values, sensitivity/specificity statistics and logistic regressions. RESULTS: At Week 9, 15 participants (7%) were identified as experiencing ICD-11 PTSD, compared to 23 (11%) experiencing ICD-10 PTSD. There was no significant difference in comorbidity rates between ICD-10 and ICD-11 PTSD diagnoses. Ninety per cent of participants with ICD-11 PTSD also met criteria for at least one CPTSD feature. Five participants met full CPTSD criteria. CONCLUSIONS: Reduced prevalence of PTSD associated with the use of ICD-11 criteria is likely to reduce identification of PTSD relative to using ICD-10 criteria but not relative to DSM-4 and DSM-5 criteria. Diagnosis of CPTSD is likely to be infrequent following single-incident trauma

    Controlled density-downramp injection in a beam-driven plasma wakefield accelerator

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    This paper describes the utilization of beam-driven plasma wakefield acceleration to implement a high-quality plasma cathode via density-downramp injection in a short injector stage at the FLASHForward facility at DESY. Electron beams with charge of up to 105 pC and energy spread of a few percent were accelerated by a tunable effective accelerating field of up to 2.7 GV/m. The plasma cathode was operated drift-free with very high injection efficiency. Sources of jitter, the emittance and divergence of the resulting beam were investigated and modeled, as were strategies for performance improvements that would further increase the wide-ranging applications for a plasma cathode with the demonstrated operational stabilityComment: 11 pages, 9 figure

    CropPol: a dynamic, open and global database on crop pollination

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    Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

    Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

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    SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

    Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

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    BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

    Association of Gulf War Illness-Related Symptoms with Military Exposures among 1990–1991 Gulf War Veterans Evaluated at the War-Related Illness and Injury Study Center (WRIISC)

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    Veterans with difficult-to-diagnose conditions who receive care in the Department of Veterans Affairs (VA) healthcare system can be referred for evaluation at one of three specialty VA War-Related Illness and Injury Study Centers (WRIISC). Veterans of the 1990–1991 Gulf War have long experienced excess rates of chronic symptoms associated with the condition known as Gulf War Illness (GWI), with hundreds evaluated at the WRIISC. Here we provide the first report from a cohort of 608 Gulf War Veterans seen at the WRIISC who completed questionnaires on chronic symptoms (>6 months) consistent with GWI as well as prominent exposures during Gulf War deployment. These included veterans’ reports of hearing chemical alarms/donning Military-Ordered Protective Posture Level 4 (MOPP4) gear, pesticide use, and use of pyridostigmine bromide (PB) pills as prophylaxis against the effects of nerve agents. Overall, veterans in the cohort were highly symptomatic and reported a high degree of exposures. In multivariable models, these exposures were significantly associated with moderate-to-severe chronic symptoms in neurocognitive/mood, fatigue/sleep, and pain domains. Specifically, exposure to pesticides was associated with problems with concentration and memory, problems sleeping, unrefreshing sleep, and joint pain. Use of MOPP4 was associated with light sensitivity and unrefreshing sleep and use of PB was associated with depression. We also evaluated the association of exposures with symptom summary scores based on veterans’ severity of symptoms in four domains and overall. In multivariable modeling, the pain symptom severity score was significantly associated with pesticide use (Odds ratio (OR): 4.13, 95% confidence intervals (CI): 1.78–9.57) and taking PB pills (OR: 2.28, 95% CI: 1.02–5.09), and overall symptom severity was significantly associated with use of PB pills (OR: 2.41, 95% CI: 1.01–5.75). Conclusion: Decades after deployment, Gulf War veterans referred to a VA tertiary evaluation center report a high burden of chronic symptoms, many of which were associated with reported neurotoxicant exposures during the war

    Controlled Density-Downramp Injection in a Beam-Driven Plasma Wakefield Accelerator

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    This paper describes the utilization of beam-driven plasma wakefield acceleration to implement a high-quality plasma cathode via density-downramp injection in a short injector stage at the FLASHForward facility at DESY. Electron beams with charge of up to 105 pC and energy spread of a few percent were accelerated by a tunable effective accelerating field of up to 2.7 GV/m. The plasma cathode was operated drift-free with very high injection efficiency. Sources of jitter, the emittance and divergence of the resulting beam were investigated and modeled, as were strategies for performance improvements that would further increase the wide-ranging applications for a plasma cathode with the demonstrated operational stabilit

    FLASHForward - A Future-Oriented Plasma Wakefield Accelerator Research and Development Facility at FLASH

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    Due to high accelerating electric fields in the range of several GV/m, beam-driven plasma wakefield accelerators (PWFAs) have outstanding potential to transform technologies, such as the design of future electron-positron colliders and free-electron lasers. At DESY in Hamburg, the FLASHForward project has recently started operation and will develop further important capabilities in future. The plasma is generated in a capillary gas cell either by gas discharge or by using a femtosecond pulse from the 25 TW Ti:Sa laser system to ionize the gas. The laser provides an ionizing main laser arm and a transverse probe laser arm. The electron bunch from the FLASH linear acclerator has energy up to 1.25 GeV and delivers up to a few kA peak current. The facility has exceptional capabilities to longitudinally shape the electron bunch, allowing plasma waves to be excited in the nonlinear blowout regime for a variety of experiments. These include the generation of high-quality electron bunches (internal injection) and post-acceleration of electron bunches form FLASH (external injection). The first interaction of the electron beam with a plasma wake has been demonstrated in June 2018, beginning the exploitation of the great potential of the FLASHForward Plasma Wakefield accelerator
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