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Background Healthcare workers (HCW) are exposed to an increased risk of COVID-19 through direct contact with patients and patient environments. We calculated the; seroprevalence of SARS-CoV-2 in HCW at Eastern Health, a tertiary healthcare network in Victoria, and assessed associations with demographics, work location and role. Methods A cross-sectional cohort study of HCW at Eastern Health was conducted. Serum was analysed for the presence of antibodies to SARS-CoV-2, and all participants completed; an online survey collecting information on demographics, place of work, role, and exposures; to COVID-19. Seroprevalence was calculated as the proportion participants with SARS-CoV-2; antibodies out of all tested individuals. Results The crude seroprevalence of SARS-CoV-2 antibodies in this study was 2.17% (16/736). Thirteen of the 16 (81.2%) positive cases had previously been diagnosed with COVID-19 by PCR: the seroprevalence in the group not previously diagnosed with COVID by PCR was 0.42% (3/720). Having direct contact with COVID-19 patients did not increase the likelihood of having positive serology. A prior history of symptoms consistent with COVID-19 was associated with a higher likelihood of having positive serology (OR 17.2, p = 0.006, 95%CI: 2.25–131.55). Conclusion Our calculated seroprevalence of 2.17% is higher than estimated in the general Australian population, but lower than that reported in HCW internationally. The; majority of those with positive serology in our study had previously been diagnosed with COVID-19 by PCR based testing. Seropositivity was not associated with interaction with COVID-19 positive patients, highlighting effective infection prevention and control practices within the workplace.

Lactate can protect against damage caused by acute brain injuries both in rodents and in human patients. Besides its role as a metabolic support and alleged preferred neuronal fuel in stressful situations, an additional signaling mechanism mediated by the hydroxycarboxylic acid receptor 1 (HCAR1) was proposed to account for lactate's beneficial effects. However, the administration of HCAR1 agonists to mice subjected to middle cerebral artery occlusion (MCAO) at reperfusion did not appear to exert any relevant protective effect. To further evaluate the involvement of HCAR1 in the protection against ischemic damage, we looked at the effect of HCAR1 absence. We subjected wild-type and HCAR1 KO mice to transient MCAO followed by treatment with either vehicle or lactate. In the absence of HCAR1, the ischemic damage inflicted by MCAO was less pronounced, with smaller lesions and a better behavioral outcome than in wild-type mice. The lower susceptibility of HCAR1 KO mice to ischemic injury suggests that lactate-mediated protection is not achieved or enhanced by HCAR1 activation, but rather attributable to its metabolic effects or related to other signaling pathways. Additionally, in light of these results, we would disregard HCAR1 activation as an interesting therapeutic strategy for stroke patients.

After ischemic stroke, in the lesion core as well as in the ischemic penumbra, evolution of tissue damage and repair is strongly affected by neuroinflammatory events that involve activation of local specialized glial cells, release of inflammatory mediators, recruiting of systemic cells and vascular remodelling. To take advantage of this intricate response in the quest to devise new protective therapeutic strategies we need a better understanding of the territorial and temporal interplay between stroke-triggered inflammatory and cell death-inducing processes in both parenchymal and vascular brain cells. Our goal is to describe structural rearrangements and functional modifications occurring in glial and vascular cells early after an acute ischemic stroke. Low and high scale mapping of the glial activation on brain sections of mice subjected to 30 minutes middle cerebral artery occlusion (MCAO) was correlated with that of the neuronal cell death, with markers for microvascular changes and with markers for pro-inflammatory (IL-1β) and reparative (TGFβ1) cytokines. Our results illustrate a time-course of the neuroinflammatory response starting at early time-points (1 h) and up to one week after MCAO injury in mice, with an accurate spatial distribution of the observed phenomena.

Here we assess the potential functional role of increased aquaporin 9 (APQ9) in astrocytes. Increased AQP9 expression was achieved in primary astrocyte cultures by transfection of a plasmid-containing green fluorescent protein fused to either wild-type or mutated human AQP9. Increased AQP9 expression and phosphorylation at Ser222 were associated with a significant change in astrocyte morphology, mainly with a higher number of processes. Similar phenotypic changes are observed in astrogliosis processes after injury. In parallel, we observed that in vivo, thrombin preconditioning before ischemic stroke induced an early increase in AQP9 expression in the male mouse brain. This increased AQP9 expression was also associated with astrocyte morphological changes, especially in the white matter tract. Astrocyte reactivity is debated as being either beneficial or deleterious. As thrombin preconditioning leads to a decrease in lesion size after stroke, our data suggest that the early increase in AQP9 concomitant with astrocyte reactivity leads to a beneficial effect. © 2017 Wiley Periodicals, Inc.

Over the centuries people have become taller, heavier, and stronger. One of the major reasons for this is the increasing supply of calories in our diets. In earlier times, weight gain was extremely beneficial for health, well-being, and lifespan, but in 2012 we are at a point where weight gain has gone too far and is now detrimental. We are facing an overeating epidemic and the adverse health effects of obesity. This article discusses some of the causes of obesity and the factors affecting it.

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common childhood disorders. First described in 1798 by Alexander Crichton, ADHD became widely known outside the medical profession with the publication of the story of Fidgety Phil (‘Zappelphilipp’) in Heinrich Hoffman’ sb ook ‘Struwwelpeter’ in 1846. Since then, scientists and clinicians have been struggling to understand its causes. To date, there is neither a genetic test nor a brain scan to diagnose ADHD due to the fact that it is a heterogeneous collection of behaviours that appear to have different causes and symptoms. In view of the lack of an objective diagnostic method, the major difficulty that specialists face is to decide where to set the threshold between behaviours and states of mind that require medication or behavioural treatment and differences that can be left alone. The increased rate in diagnosis and stimulant use in ADHD recently raises several issues, notably, are we setting lower diagnostic thresholds because of societies’ intolerance of behaviours and impairments associated with ADHD? This article discusses some of the controversies in ADHD diagnosis and treatment, including many medical, social, and ethical aspects.

Objective: This retrospective, observational cohort study investigated whether the clinical features of a patient's pain, including anatomical location, organ system and likely treating speciality, impact on the delivery of analgesia within 30min in EDs. Methods: Data were obtained from 24 centres across Australia between April 2008 and March 2009. Principal outcome was delivery of analgesia within 30min or less. Factors that might explain any differences were analysed, including anatomical location of the pain, likely treating speciality, organ system affected, age, sex, day and time of presentation, hospital location, documented pain score and triage category. Analysis was by the χ -test for independence of proportions and multiple logistic regression. A P-value

Thrombin plays a role in cerebral ischemia as rats subjected to focal cerebral ischemia were protected by the intracerebral injection of hirudin, a selective thrombin inhibitor. To separate the roles of thrombin in cell death and in coagulation, we have used an in vitro approach to test the effect of hirudin and of protease nexin-1 (PN-1), a cerebral thrombin inhibitor, on neuronal ischemia. Rat organotypic hippocampal slice cultures were subjected to oxygen (5%) and glucose (1 mmol/L) deprivation (OGD) during 30 min. Hirudin or PN-1 administered after OGD significantly prevented neuronal death in the CA1 region. After 24 h, there was a marked increase in thrombin immunoreactivity on Western blots. Thrombin therefore contributes to ischemic damage in neural tissue in vitro.

In cerebral ischemic preconditioning (IPC), a first sublethal ischemia increases the resistance of neurons to a subsequent severe ischemia. Despite numerous studies, the mechanisms are not yet fully understood. Our goal is to develop an in vitro model of IPC on hippocampal organotypic slice cultures. Instead of anoxia, we chose to apply varying degrees of hypoxia that allows us various levels of insult graded from mild to severe. Cultures are exposed to combined oxygen and glucose deprivation (OGD) of varying intensities, ranging from mild to severe, assessing both the electrical activity and cell death. IPC was accomplished by exposure to the mildest ischemia condition (10% of O2 for 15 min) 24 h before the severe deprivation (5% of O2 for 30 min). Interestingly, IPC not only prevented delayed ischemic cell death 6 days after insult but also the transient loss of evoked potential response. The major interest and advantage of this system over both the acute slice preparation and primary cell cultures is the ability to simultaneously measure the delayed neuronal damage and neuronal function.

Aquaporins (AQPs) are water channel molecules that allow the passage of water through the lipid bilayers of cell membranes. AQP1, AQP4 and AQP9 are expressed in the central nervous system and AQP4 is well known as the target of auto-antibodies in Devic&rsquo, s neuromyelitis optica. The role of AQPs in facilitating water movements suggests a link with oedema formation and resolution in the brain. Furthermore, AQPs are also involved in process formation in glial cells with a close link to neuroinflammation. This mini-review gives an overview of what is currently known about the role of AQPs in different neurological disorders.

Chromatin architecture plays a decisive role in many aspects of transcription regulation. We have tested the role of specific chromatin structures in c- fos gene regulation, using a gene transfer system based on episomes derived from the Epstein–Barr virus (EBV). This system reproduces in several respects the chromatin structure and regulation of the chromosomal c- fos gene. Using this approach, we first demonstrate that the pausing of RNA polymerase II downstream of the transcriptional start site does not require precisely positioned nucleosomes. Indeed, changing the pattern of MNase hypersensitive sites along the transcribed sequence does not perturb RNA polymerase II pausing or the regulation of the c- fos gene. Next, we show that a putative nucleosome positioned between the SIE/SRE elements (−300) and the CRE/TATA elements (−36) is not necessary for activation by a variety of inducers. Accordingly, total or partial deletion of the putative nucleosome sequence does not disturb c- fos regulation while the two regulatory sites flanking the nucleosome sequence remain hypersensitive to MNase. As described in this paper, EBV episomes are useful vectors to critically examine the role of the chromatin structure in gene transcription for human cells.

Hepatocyte growth factor/scatter factor (HGF/SF) is a recently characterised molecule with many remarkable functions. Its involvement in important processes such as cell proliferation, cell migration, morphogenesis and organ development implies that its activity should be tightly regulated. To understand the molecular mechanisms controlling HGF/SF transcription, we have analysed DNaseI hypersensitive sites (DHS) along rat and human HGF/SF genes in various tissues and cell types. We identified five DHS along the rat gene, two in the 5′-flanking region and three in the first intron. These sites are only found in rat tissues and rat cell lines, which express HGF/SF. The strongest hypersensitive site maps to a region that corresponds to the promoter by start site analysis. A single tissue-specific DHS is present in human cell lines that express HGF/SF and corresponds to the promoter region. Our results suggest that chromatin accessibility plays a major role in the regulation of HGF/SF transcription regulation.

The serine protease thrombin plays a role in signalling ischemic neuronal death in the brain. Paradoxically, endogenous neuroprotective mechanisms can be triggered by preconditioning with thrombin (thrombin preconditioning, TPC), leading to tolerance to cerebral ischemia. Here we studied the role of thrombin's endogenous potent inhibitor, protease nexin-1 (PN-1), in ischemia and in tolerance to cerebral ischemia induced by TPC. Cerebral ischemia was modelled in vitro in organotypic hippocampal slice cultures from rats or genetically engineered mice lacking PN-1 or with the reporter gene lacZ knocked into the PN-1 locus PN-1HAPN-1-lacZ/HAPN-1-lacZ (PN-1 KI) exposed to oxygen and glucose deprivation (OGD). We observed increased thrombin enzyme activity in culture homogenates 24 h after OGD. Lack of PN-1 increased neuronal death in the CA1, suggesting that endogenous PN-1 inhibits thrombin-induced neuronal damage after ischemia. OGD enhanced β-galactosidase activity, reflecting PN-1 expression, at one and 24 h, most strikingly in the stratum radiatum, a glial cell layer adjacent to the CA1 layer of ischemia sensitive neurons. TPC, 24 h before OGD, additionally increased PN-1 expression 1 h after OGD, compared to OGD alone. TPC failed to induce tolerance in cultures from PN-1(-/-) mice confirming PN-1 as an important TPC target. PN-1 upregulation after TPC was blocked by the c-Jun N-terminal kinase (JNK) inhibitor, L-JNKI1, known to block TPC. This work suggests that PN-1 is an endogenous neuroprotectant in cerebral ischemia and a potential target for neuroprotection.

This retrospective, observational cohort study investigated whether the clinical features of a patient's pain, including anatomical location, organ system and likely treating speciality, impact on the delivery of analgesia within 30 min in EDs.Data were obtained from 24 centres across Australia between April 2008 and March 2009. Principal outcome was delivery of analgesia within 30 min or less. Factors that might explain any differences were analysed, including anatomical location of the pain, likely treating speciality, organ system affected, age, sex, day and time of presentation, hospital location, documented pain score and triage category. Analysis was by the χ(2)-test for independence of proportions and multiple logistic regression. A P-value0.05 was considered statistically significant.There were 4598 patients, of whom 2578 were male. The median age was 36 years (range 0-103). Both limb origin of pain (χ(2) = 46.1, P0.001) and documentation of a pain score (χ(2) = 48.6, P0.001) were strongly associated with delivery of analgesia within 30 min. Attending a rural ED was a significant risk factor for delayed analgesia (χ(2) = 12.5, P0.001). Burns patients (40.2%, 47 of 117, P0.001) and orthopaedic patients (26.1%, 259 of 992, P0.001) were much more likely to received analgesia within 30 min than the mean (19.5%, 896 of 4598).Patients presenting with burns, orthopaedic conditions or with a limb location of pain are more likely to receive analgesia within 30 min in Australian EDs. Clinicians should be aware of possible trends in the delivery of timely analgesia to patients with pain.

To identify and prioritize the key research questions in psycho-oncology in order to guide the development of large multicenter clinically relevant studies.All members of the Psycho-Oncology Co-operative Research Group (n = 295) were invited to participate in an online survey and 180 responded (response rate = 61%). Participants rated eight priority research areas identified from a previous focus group study on a five-point scale, and ranked their top four priority areas. Within the four ranked research areas, participants selected the three most important specific research questions.The highest rated research priority areas were distress identification (23.3%), survivorship (22.7%), and distress management (15.3%), followed by issues relating to health services (9.7%) and carers (8.0%). Interventions were commonly nominated among the most important research questions within each priority area. The single most important research question identified by 44% of the sample was to "Determine the most acceptable, reliable and valid screening tool to be administered routinely at diagnosis and at other key transition points to identify distress and psychosocial needs".This is the first Australian study to explore research priorities in psycho-oncology, and the first international study to explore these issues in depth. To ensure that the research effort is strategic, clinically relevant and cost-effective, clear priorities need to be established. The results of this survey will enable limited resources to focus on key research questions of direct clinical benefit.

We have analysed the expression pattern of the mouse homeobox containing gene Dlx-1. This gene harbors a homeodomain related to that found in the Drosophila distal-less (dll) gene. In addition to its expression in the developing forebrain, Dlx-1 is transcribed in several structures containing cells of neural crest origin such as the facial mesenchyme and various elements of the peripheral nervous system. Dlx-1 transcripts are also detected in the differentiating retina and during limb morphogenesis, in the apical ectodermal ridge. The possible involvement of Dlx-1 during facial, ocular and limb development is discussed.

Thrombin is involved in mediating neuronal death in cerebral ischemia. We investigated its so far unknown mode of activation in ischemic neural tissue. We used an in vitro approach to distinguish the role of circulating coagulation factors from endogenous cerebral mechanisms. We modeled ischemic stroke by subjecting rat organotypic hippocampal slice cultures to 30-min oxygen (5%) and glucose (1 mmol/L) deprivation (OGD). Perinuclear activated factor X (FXa) immunoreactivity was observed in CA1 neurons after OGD. Selective FXa inhibition by fondaparinux during and after OGD significantly reduced neuronal death in the CA1 after 48 h. Thrombin enzyme activity was increased in the medium 24 h after OGD and this increase was prevented by fondaparinux suggesting that FXa catalyzes the conversion of prothrombin to thrombin in neural tissue after ischemia in vitro. Treatment with SCH79797, a selective antagonist of the thrombin receptor protease-activated receptor-1 (PAR-1), significantly decreased neuronal cell death indicating that thrombin signals ischemic damage via PAR-1. The c-Jun N-terminal kinase (JNK) pathway plays an important role in excitotoxicity and cerebral ischemia and we observed activation of the JNK substrate, c-Jun in our model. Both the FXa inhibitor, fondaparinux and the PAR-1 antagonist SCH79797, decreased the level of phospho-c-Jun Ser73. These results indicate that FXa activates thrombin in cerebral ischemia, which leads via PAR-1 to the activation of the JNK pathway resulting in neuronal death.

Recently it has been shown that the c-Jun N-terminal kinase (JNK) plays a role in thrombin preconditioning (TPC) in vivo and in vitro. To investigate further the pathways involved in TPC, we performed an immunohistochemical study in hippocampal slice cultures. Here we show that the major target of JNK, the AP-1 transcription factor c-Jun, is activated by phosphorylation in the nuclei of neurons of the CA1 region by using phospho-specific antibodies against the two JNK phosphorylation sites. The activation is early and transient, peaking at 90 min and not present by 3 hr after low-dose thrombin administration. Treatment of cultures with a synthetic thrombin receptor agonist results in the same c-Jun activation profile and protection against subsequent OGD, both of which are prevented by specific JNK inhibitors, showing that thrombin signals through PAR-1 to JNK. By using an antibody against the Ser 73 phosphorylation site of c-Jun, we identify possible additional TPC substrates.

Aquaporin 4 (AQP4) is a water channel involved in water movements across the cell membrane and is spatially organized on the cell surface in orthogonal array particles (OAPs). Its role in edema formation or resolution after stroke onset has been studied mainly at late time points. We have shown recently that its expression is rapidly induced after ischemia coinciding in time with an early swelling of the ischemic hemisphere. There are two isoforms of AQP4: AQP4-M1 and AQP4-M23. The ratio of these isoforms influences the size of the OAPs but the functional impact is not known. The role of the early induction of AQP4 is not yet known. Thrombin preconditioning in mice provides a useful model to study endogenous protective mechanisms. Using this model, we provide evidence for the first time that the early induction of AQP4 may contribute to limit the formation of edema and that the AQP4-M1 isoform is predominantly induced in the ischemic tissue at this time point. Although it prevents edema formation, the early induction of the AQP4 expression does not prevent the blood—brain barrier disruption, suggesting an effect limited to the prevention of edema formation possibly by removing of water from the tissue.

We have studied ischemic tolerance induced by the serine protease thrombin in two different models of experimental ischemia. In organotypic hippocampal slice cultures, we demonstrate that incubation with low doses of thrombin protects neurons against a subsequent severe oxygen and glucose deprivation. L-JNKI1, a highly specific c-jun N-terminal kinase (JNK) inhibitor, and a second specific JNK inhibitor, SP600125, prevented thrombin preconditioning (TPC). We also show that the exposure to thrombin increases the level of phosphorylated c-jun, the major substrate of JNK. TPC, in vivo, leads to significantly smaller lesion sizes after a 30-min middle cerebral artery occlusion (MCAo), and the preconditioned mice were better off in the three tests used to evaluate functional recovery. In accordance with in vitro results, TPC in vivo was prevented by administration of L-JNKI1, supporting a role for JNK in TPC. These results, from two different TPC models and with two distinct JNK inhibitors, show that JNK is likely to be involved in TPC.

Ischemic stroke is an important cause of mortality and invalidity. Focal cerebral ischemia induces multiple and complex mechanisms leading to the loss of function and the demise of cerebral tissue. Apoptosis, or programmed cell death, well known for its role in normal development, is one of these mechanisms, and contributes to ischemic neuronal death. This short review gives an overview of apoptotic mechanisms triggered by cerebral ischemia.

Members of the vertebrate Dlx- and Nkx2-homeobox-containing gene families exhibit closely related, complementary areas of gene expression in the developing forebrain. The expression domains and onset of gene transcription indicate that these genes may play a role in forebrain patterning, particularly in the diencephalon. In some cases, gene expression borders coincide with morphological boundaries separating functional and anatomical regions of the forebrain suggesting that the rostral region of the neural tube may indeed arise frm a segmented structure.

Seal myoglobin (Mb) exons 1 and 3 were used as probes to isolate the functional mouse Mb gene. This gene has a very low level of Mb expression in skeletal muscle. Although it is shorter, the mouse Mb gene displays the common organisation found in human and seal Mb genes. In addition, we have defined blocks of conserved sequences in the 5' flanking region by comparison with other mammalian Mb genes. Moreover, about 10(3) bases upstream of the cap site we identified a repetitive B1 element directly associated with two overlapping open reading frames, containing a putative polyadenylation signal. A polypyrimidine-rich region has also been located upstream from the gene.