165 research outputs found

    Investigation into the biochemical changes in Tourette Syndrome with a potential for pharmacological manipulation

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    Kynurenine (KYN) is the first stable metabolite of the kynurenine pathway, which accounts for over 95% of tryptophan metabolism. Two previous studies by this research group reported elevated plasma KYN in Tourette syndrome (TS) patients when compared with age and sex matched controls and another study showed that KYN potentiated 5-HT2A-mediated head-shakes (HS) in rodents. These movements have been suggested to model tics in TS. This raised the questions how KYN acts in eliciting this response and whether it is an action of its own or of a further metabolite along the kynurenine pathway. In the liver, where most of the kynurenine pathway metabolism takes place under physiological conditions, the first and the rate limiting enzyme is tryptophan-dioxygenase (TDO) which can be induced by cortisol. In extrahepatic tissues the same step of the pathway is catalyzed by indoleamine-dioxygenase (IDO), which is induced by cytokines, predominantly interferon-y (INF-y). Plasma neopterin, which shows parallel increase with KYN following immune stimulation, was also found elevated in one of these studies positively correlating with KYN. In the present work animal studies suggested that KYN potentiates and quinolinic acid (QUINA) dose dependently inhibits the 5-HT2A-mediated HS response in mice. The potentiating effect seen with KYN was suggested to be an effect of KYN itself. Radioligand binding and phosphoinositide (PI) hydrolysis studies were done to explore the mechanisms by which kynurenine pathway metabolites could alter a 5-HT2A-receptor mediated response. None of the kynurenine pathway metabolites tested showed direct binding to 5-HT2A-receptors. PI hydrolysis studies with KYN and QUINA showed that KYN did not have any effect while QUINA inhibited 5-HT2A-mediated PI hydrolysis. Plasma cortisol determination in TS patients with elevated plasma KYN did not show elevated plasma cortisol levels, suggesting that the increase of plasma KYN in these TS patients is unlikely to be due to an increased TDO activity induced by increased cortisol. Attention deficit hyperactivity disorder (ADHD) is commonly associated with TS. Salivary cortisol detected in a group of children primarily affected with ADHD showed significantly lower salivary cortisol levels when compared with age and sex matched controls. Plasma tryptophan, KYN, neopterin, INF-y and KYN/tryptophan ratio and night-time urinary 6-sulphatoxymelatonin (aMT6s) excretion measured in a group of TS patients did not show any difference in their levels when compared with age and sex matched controls, but TS patients failed to show the expected positive correlation seen between plasma INF-y, neopterin and KYN and the negative correlation seen between plasma KYN and night-time urinary aMT6s excretion seen in healthy controls. The relevance of the kynurenine pathway, melatonin secretion and cortisol to Tourette Syndrome and associated conditions and the mechanism by which KYN and QUINA alter the 5-HT2A-receptor mediated HS response are discussed

    FitFlame – Health and Fitness Coaching Application to Mitigate the Issues in the Current Applications

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    Online fitness coaches help people achieve a healthy lifestyle by offering customized solutions. The demand for professional coaching is expected to grow in the coming years. Nevertheless, no applications in the market address the problems in the coaching process. Today, coaches and clients had to use many third-party apps. The reason for this is that no single fitness coaching app offers communication and exercise-tracking features. Even though some apps meet some of these requirements, they are out of reach for most people's budgets. This paper aims to suggest a robust and full-fledged app to mitigate those issues. FitFlame is the name of the proposed app. Both coaches and clients can benefit from this app. Also, FitFlame is a fitness coaching system available on mobile and the web. It helps clients locate and contact coaches, subscribe to coaching plans, and track their progress. It does away with third-party programs and gives users a better experience

    An annotated checklist of bryophytes of Europe, Macaronesia and Cyprus

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    Introduction. Following on from work on the European bryophyte Red List, the taxonomically and nomenclaturally updated spreadsheets used for that project have been expanded into a new checklist for the bryophytes of Europe. Methods. A steering group of ten European bryologists was convened, and over the course of a year, the spreadsheets were compared with previous European checklists, and all changes noted. Recent literature was searched extensively. A taxonomic system was agreed, and the advice and expertise of many European bryologists sought. Key results. A new European checklist of bryophytes, comprising hornworts, liverworts and mosses, is presented. Fifteen new combinations are proposed. Conclusions. This checklist provides a snapshot of the current European bryophyte flora in 2019. It will already be out-of-date on publication, and further research, particularly molecular work, can be expected to result in many more changes over the next few years.Peer reviewe

    Activin-A induces regulatory T cells that suppress T helper cell immune responses and protect from allergic airway disease

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    Activin-A is a pleiotropic cytokine that participates in developmental, inflammatory, and tissue repair processes. Still, its effects on T helper (Th) cell–mediated immunity, critical for allergic and autoimmune diseases, are elusive. We provide evidence that endogenously produced activin-A suppresses antigen-specific Th2 responses and protects against airway hyperresponsiveness and allergic airway disease in mice. Importantly, we reveal that activin-A exerts suppressive function through induction of antigen-specific regulatory T cells that suppress Th2 responses in vitro and upon transfer in vivo. In fact, activin-A also suppresses Th1-driven responses, pointing to a broader immunoregulatory function. Blockade of interleukin 10 and transforming growth factor β1 reverses activin-A–induced suppression. Remarkably, transfer of activin-A–induced antigen-specific regulatory T cells confers protection against allergic airway disease. This beneficial effect is associated with dramatically decreased maturation of draining lymph node dendritic cells. Therapeutic administration of recombinant activin-A during pulmonary allergen challenge suppresses Th2 responses and protects from allergic disease. Finally, we demonstrate that immune cells infiltrating the lungs from individuals with active allergic asthma, and thus nonregulated inflammatory response, exhibit significantly decreased expression of activin-A's responsive elements. Our results uncover activin-A as a novel suppressive factor for Th immunity and a critical controller of allergic airway disease

    Chronic Respiratory Aeroallergen Exposure in Mice Induces Epithelial-Mesenchymal Transition in the Large Airways

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    Chronic allergic asthma is characterized by Th2-polarized inflammation and leads to airway remodeling and fibrosis but the mechanisms involved are not clear. To determine whether epithelial-mesenchymal transition contributes to airway remodeling in asthma, we induced allergic airway inflammation in mice by intranasal administration of house dust mite (HDM) extract for up to 15 consecutive weeks. We report that respiratory exposure to HDM led to significant airway inflammation and thickening of the smooth muscle layer in the wall of the large airways. Transforming growth factor beta-1 (TGF-β1) levels increased in mouse airways while epithelial cells lost expression of E-cadherin and occludin and gained expression of the mesenchymal proteins vimentin, alpha-smooth muscle actin (α-SMA) and pro-collagen I. We also observed increased expression and nuclear translocation of Snail1, a transcriptional repressor of E-cadherin and a potent inducer of EMT, in the airway epithelial cells of HDM-exposed mice. Furthermore, fate-mapping studies revealed migration of airway epithelial cells into the sub-epithelial regions of the airway wall. These results show the contribution of EMT to airway remodeling in chronic asthma-like inflammation and suggest that Th2-polarized airway inflammation can trigger invasion of epithelial cells into the subepithelial regions of the airway wall where they contribute to fibrosis, demonstrating a previously unknown plasticity of the airway epithelium in allergic airway disease

    Onasemnogene abeparvovec in spinal muscular atrophy: an Australian experience of safety and efficacy

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    First published: 16 February 2022Objective: To provide a greater understanding of the tolerability, safety and clinical outcomes of onasemnogene abeparvovec in real-world practice, in a broad population of infants with spinal muscular atrophy (SMA). Methods: A prospective cohort study of children with SMA treated with onasemnogene abeparvovec at Sydney Children's Hospital Network, Australia was conducted from August 2019 to November 2021. Safety outcomes included clinical and laboratory evaluations. Efficacy assessments included World Health Organisation (WHO) motor milestones, oral and swallowing abilities, and requirements for respiratory support. The implementation of a model of care for onasemnogene abeparvovec administration in health practice is described. Results: 21 children were treated (age range, 0.65–24 months; body weight range, 2.5–12.5 kg) and 19/21 (90.4%) had previous nusinersen. Transient treatment-related side effects occurred in all children; vomiting (100%), transaminitis (57%) and thrombocytopaenia (33%). Incidence of moderate/severe transaminitis was significantly greater in infants weighing ≥8 kg compared with <8 kg (p < 0.05). Duration of prednisolone following treatment was prolonged (mean 87.5 days, range 57–274 days). 16/21 (76%) children gained at least one WHO motor milestone. Stabilisation or improvement in bulbar or respiratory function was observed in 20/21 (95.2%) patients. Implementation challenges were mitigated by developing standard operating procedures and facilitating exchange of knowledge. Interpretation: This study provides real-world evidence to inform treatment decisions and guide therapeutic expectations for onasemnogene abeparvovec and combination therapy for SMA in health practice, especially for children weighing ≥8 kg receiving higher vector loads. Proactive clinical and laboratory surveillance is essential to facilitate individualised management of risks.Arlene M. D’Silva, Sandra Holland, Didu Kariyawasam, Karen Herbert, Peter Barclay, Anita Cairns, Suzanna C. MacLennan, Monique M. Ryan, Hugo Sampaio, Nicholas Smith, Ian R. Woodcock, Eppie M. Yiu, Ian E. Alexander and Michelle A. Farra

    Attenuated expression of tenascin-c in ovalbumin-challenged STAT4-/- mice

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    <p>Abstract</p> <p>Background</p> <p>Asthma leads to structural changes in the airways, including the modification of extracellular matrix proteins such as tenascin-C. The role of tenascin-C is unclear, but it might act as an early initiator of airway wall remodelling, as its expression is increased in the mouse and human airways during allergic inflammation. In this study, we examined whether Th1 or Th2 cells are important regulators of tenascin-C in experimental allergic asthma utilizing mice with impaired Th1 (STAT4-/-) or Th2 (STAT6-/-) immunity.</p> <p>Methods</p> <p>Balb/c wildtype (WT), STAT4-/- and STAT6-/- mice were sensitized with intraperitoneally injected ovalbumin (OVA) followed by OVA or PBS airway challenge. Airway hyperreactivity (AHR) was measured and samples were collected. Real time PCR and immunohistochemistry were used to study cytokines and differences in the expression of tenascin-C. Tenascin-C expression was measured in human fibroblasts after treatment with TNF-α and IFN-γ <it>in vitro</it>.</p> <p>Results</p> <p>OVA-challenged WT mice showed allergic inflammation and AHR in the airways along with increased expression of TNF-α, IFN-γ, IL-4 and tenascin-C in the lungs. OVA-challenged STAT4-/- mice exhibited elevated AHR and pulmonary eosinophilia. The mRNA expression of TNF-α and IFN-γ was low, but the expression of IL-4 was significantly elevated in these mice. OVA-challenged STAT6-/- mice had neither AHR nor pulmonary eosinophilia, but had increased expression of mRNA for TNF-α, IFN-γ and IL-4. The expression of tenascin-C in the lungs of OVA-challenged STAT4-/- mice was weaker than in those of OVA-challenged WT and STAT6-/- mice suggesting that TNF-α and IFN-γ may regulate tenascin-C expression <it>in vivo</it>. The stimulation of human fibroblasts with TNF-α and IFN-γ induced the expression of tenascin-C confirming our <it>in vivo </it>findings.</p> <p>Conclusions</p> <p>Expression of tenascin-C is significantly attenuated in the airways of STAT4-/- mice, which may be due to the impaired secretion of TNF-α and IFN-γ in these mice.</p

    Characteristics of adults with type 1 diabetes and treatment-resistant problematic hypoglycaemia: a baseline analysis from the HARPdoc RCT

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    Aims/hypothesis Problematic hypoglycaemia still complicates insulin therapy for some with type 1 diabetes. This study describes baseline emotional, cognitive and behavioural characteristics in participants in the HARPdoc trial, which evaluates a novel intervention for treatment-resistant problematic hypoglycaemia. Methods We documented a cross-sectional baseline description of 99 adults with type 1 diabetes and problematic hypoglycaemia despite structured education in flexible insulin therapy. The following measures were included: Hypoglycaemia Fear Survey II (HFS-II); Attitudes to Awareness of Hypoglycaemia questionnaire (A2A); Hospital Anxiety and Depression Index; and Problem Areas In Diabetes. k-mean cluster analysis was applied to HFS-II and A2A factors. Data were compared with a peer group without problematic hypoglycaemia, propensity-matched for age, sex and diabetes duration (n = 81). Results The HARPdoc cohort had long-duration diabetes (mean ± SD 35.8 ± 15.4 years), mean ± SD Gold score 5.3 ± 1.2 and a median (IQR) of 5.0 (2.0–12.0) severe hypoglycaemia episodes in the previous year. Most individuals had been offered technology and 49.5% screened positive for anxiety (35.0% for depression and 31.3% for high diabetes distress). The cohort segregated into two clusters: in one (n = 68), people endorsed A2A cognitive barriers to hypoglycaemia avoidance, with low fear on HFS-II factors; in the other (n = 29), A2A factor scores were low and HFS-II high. Anxiety and depression scores were significantly lower in the comparator group. Conclusions/interpretation The HARPdoc protocol successfully recruited people with treatment-resistant problematic hypoglycaemia. The participants had high anxiety and depression. Most of the cohort endorsed unhelpful health beliefs around hypoglycaemia, with low fear of hypoglycaemia, a combination that may contribute to persistence of problematic hypoglycaemia and may be a target for adjunctive psychological therapies
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