178 research outputs found

    Interference of the T cell and antigen-presenting cell costimulatory pathway using CTLA4-Ig (abatacept) prevents Staphylococcal enterotoxin B pathology

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    Abstract Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that binds the receptors in the APC/T cell synapse and causes increased proliferation of T cells and a cytokine storm syndrome in vivo. Exposure to the toxin can be lethal and cause significant pathology in humans. The lack of effective therapies for SEB exposure remains an area of concern, particularly in scenarios of acute mass casualties. We hypothesized that blockade of the T cell costimulatory signal by the CTLA4-Ig synthetic protein (abatacept) could prevent SEB-dependent pathology. In this article, we demonstrate mice treated with a single dose of abatacept 8 h post SEB exposure had reduced pathology compared with control SEB-exposed mice. SEB-exposed mice showed significant reductions in body weight between days 4 and 9, whereas mice exposed to SEB and also treated with abatacept showed no weight loss for the duration of the study, suggesting therapeutic mitigation of SEB-induced morbidity. Histopathology and magnetic resonance imaging demonstrated that SEB mediated lung damage and edema, which were absent after treatment with abatacept. Analysis of plasma and lung tissues from SEB-exposed mice treated with abatacept demonstrated significantly lower levels of IL-6 and IFN-γ (p &amp;lt; 0.0001), which is likely to have resulted in less pathology. In addition, exposure of human and mouse PBMCs to SEB in vitro showed a significant reduction in levels of IL-2 (p &amp;lt; 0.0001) after treatment with abatacept, indicating that T cell proliferation is the main target for intervention. Our findings demonstrate that abatacept is a robust and potentially credible drug to prevent toxic effects from SEB exposure.</jats:p

    The conformational state of Tes regulates its zyxin-dependent recruitment to focal adhesions

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    The function of the human Tes protein, which has extensive similarity to zyxin in both sequence and domain organization, is currently unknown. We now show that Tes is a component of focal adhesions that, when expressed, negatively regulates proliferation of T47D breast carcinoma cells. Coimmunoprecipitations demonstrate that in vivo Tes is complexed with actin, Mena, and vasodilator-stimulated phosphoprotein (VASP). Interestingly, the isolated NH2-terminal half of Tes pulls out α-actinin and paxillin from cell extracts in addition to actin. The COOH-terminal half recruits zyxin as well as Mena and VASP from cell extracts. These differences suggest that the ability of Tes to associate with α-actinin, paxillin, and zyxin is dependent on the conformational state of the molecule. Consistent with this hypothesis, we demonstrate that the two halves of Tes interact with each other in vitro and in vivo. Using fibroblasts lacking Mena and VASP, we show that these proteins are not required to recruit Tes to focal adhesions. However, using RNAi ablation, we demonstrate that zyxin is required to recruit Tes, as well as Mena and VASP, but not vinculin or paxillin, to focal adhesions

    Understanding Ricin from a Defensive Viewpoint

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    The toxin ricin has long been understood to have potential for criminal activity and there has been concern that it might be used as a mass-scale weapon on a military basis for at least two decades. Currently, the focus has extended to encompass terrorist activities using ricin to disrupt every day activities on a smaller scale. Whichever scenario is considered, there are features in common which need to be understood; these include the knowledge of the toxicity from ricin poisoning by the likely routes, methods for the detection of ricin in relevant materials and approaches to making an early diagnosis of ricin poisoning, in order to take therapeutic steps to mitigate the toxicity. This article will review the current situation regarding each of these stages in our collective understanding of ricin and how to defend against its use by an aggressor

    SCOPE1: a randomised phase II/III multicentre clinical trial of definitive chemoradiation, with or without cetuximab, in carcinoma of the oesophagus

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    <p>Abstract</p> <p>Background</p> <p>Chemoradiotherapy is the standard of care for patients with oesophageal cancer unsuitable for surgery due to the presence of co-morbidity or extent of disease, and is a standard treatment option for patients with squamous cell carcinoma of the oesophagus. Modern regimens of chemoradiotherapy can lead to significant long-term survival. However the majority of patients will die of their disease, most commonly with local progression/recurrence of their tumours. Cetuximab may overcome one of the principal mechanisms of tumour radio-resistance, namely tumour repopulation, in patients treated with chemoradiotherapy.</p> <p>The purpose of this research is first to determine whether the addition of cetuximab to definitive chemoradiotherapy for treatment of patients with non-metastatic carcinoma of the oesophagus is active (in terms of failure-free rate), safe, and feasible within the context of a multi-centre randomised controlled trial in the UK. If the first stage is successful then the trial will continue to accrue sufficient patients to establish whether the addition of cetuximab to the standard treatment improves overall survival.</p> <p>Methods/Design</p> <p>SCOPE1 is a two arm, open, randomised multicentre Phase II/III trial. Eligible patients will have histologically confirmed carcinoma of the oesophagus and have been chosen to receive definitive chemoradiotherapy by an accredited multidisciplinary team including a specialist Upper GI surgeon. 420 patients will be randomised to receive definitive chemoradiotherapy with or without cetuximab using a 1:1 allocation ratio.</p> <p>During Phase II of the study, the trial will assess safety (toxicity), activity (failure-free rate) and feasibility (recruitment rate and protocol dose modifications/delays) in 90 patients in the experimental arm. If the experimental arm is found to be active, safe, and feasible by the Independent Data Monitoring Committee then recruitment will continue into Phase III. This second stage will recruit a further 120 patients into each arm and compare the overall survival of both groups.</p> <p>All patients randomised into Phase II will contribute to the Phase III comparison of overall survival. In addition to overall survival, Phase III of the study will also assess toxicity, health related quality of life and cost effectiveness. A detailed radiotherapy protocol and quality assurance procedure has been incorporated into this trial.</p> <p>Trial registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN47718479">ISRCTN47718479</a></p

    Pelargonium sidoides root extract for the treatment of acute cough due to lower respiratory tract infection in adults::a feasibility double-blind, placebo-controlled randomised trial

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    BACKGROUND: Pelargonium sidoides DC (Geraniaceae) root extract, EPs®7630 or "Kaloba®", is a widely used herbal remedy for respiratory infections, with some evidence of effectiveness for acute bronchitis. However, it is not yet widely recommended by medical professionals in the UK. There is a need to undertake appropriately designed randomised trials to test its use as an alternative to antibiotics. The aim was to assess the feasibility of conducting a double-blind randomised controlled trial of Pelargonium sidoides root extract for treatment of acute bronchitis in UK primary care, investigating intervention compliance, patient preference for dosage form and acceptability of patient diaries.STUDY DESIGN: Feasibility double-blind randomised placebo-controlled clinical trial.METHODS: We aimed to recruit 160 patients with cough (≤ 21 days) caused by acute bronchitis from UK general practices. Practices were cluster-randomised to liquid or tablet preparations and patients were individually randomised to Kaloba® or placebo. We followed participants up for 28 days through self-reported patient diaries with telephone support and reviewed medical records at one month. Outcomes included recruitment, withdrawal, safety, reconsultation and symptom diary completion rates. We also assessed treatment adherence, antibiotic prescribing and consumption, mean symptom severity (at days 2-4 after randomisation) and time to symptom resolution. We interviewed 29 patients and 11 health professionals to identify barriers and facilitators to running such a randomised trial.RESULTS: Of 543 patients screened, 261 were eligible, of whom 134 (51%) were recruited and 103 (77%) returned a completed diary. Overall, 41% (41/100) of patients took antibiotics (Kaloba® liquid group: 48% [15/31]; placebo liquid group: 23% [6/26]; Kaloba® tablet group: 48% [9/21]; placebo tablet group: 50% [11/22]). Most patients adhered to the study medication (median 19 out of 21 doses taken in week 1, IQR 18-21 - all arms combined). There were no serious adverse events relating to treatment. Most patients interviewed found study recruitment to be straightforward, but some found the diary too complex.CONCLUSIONS: It was feasible and acceptable to recruit patients from UK primary care to a double-blind placebo-controlled trial of herbal medicine (Kaloba®) for the treatment of acute bronchitis, with good retention and low data attrition.TRIAL REGISTRATION: HATRIC was registered on the ISRCTN registry ( ISRCTN17672884 ) on 16 August 2018, retrospectively registered. The record can be found at http://www.isrctn.com/ISRCTN17672884 .</p

    Use of a Javidâ„¢ shunt in the management of axillary artery injury as a complication of fracture of the surgical neck of the humerus: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Axillary artery injury is a rare but severe complication of fractures of the surgical neck of the humerus.</p> <p>Case presentation</p> <p>We present a case of axillary artery pseudoaneurysm secondary to such a fracture, in a 82-year-old white woman, presenting 10 weeks after the initial injury, successfully treated with subclavian to brachial reversed vein bypass together with simultaneous open reduction and internal fixation of the fracture. We discuss the use of a Javidâ„¢ shunt during combined upper limb revascularisation and open reduction and internal fixation of the fractured humerus.</p> <p>Conclusion</p> <p>This case highlights the usefulness of a Javidâ„¢ shunt, over other forms of vascular shunts, in prompt restoration of blood flow to effect limb salvage. It can be considered as a temporary measure whilst awaiting definitive revascularisation which can be performed following fracture fixation.</p

    Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review

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    The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59–0.90% and 0.77–1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups

    A randomised phase 2a study to investigate the effects of blocking interleukin-33 with tozorakimab in patients hospitalised with COVID-19:Accord-2

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    BACKGROUND: Increased serum interleukin (IL)-33 predicts poor outcomes in patients hospitalised with coronavirus disease 2019 (COVID-19). We examined the efficacy and safety of tozorakimab, a monoclonal antibody that neutralises IL-33, in improving outcomes in ACCORD-2 (EudraCT: 2020-001736-95).METHODS: ACCORD-2 was an open-label, phase 2a study in adults hospitalised with COVID-19. Patients were randomised 1:1 to tozorakimab 300 mg plus standard of care (SoC) or SoC alone. The primary end-point was time to clinical response (sustained clinical improvement of ≥2 points on the World Health Organization ordinal scale, discharge from hospital or fit for discharge) by day 29. Other end-points included death or respiratory failure, mortality and intensive care unit admission by day 29, and safety. Serum IL-33/soluble stimulated-2 (sST2) complex levels were measured by high-sensitivity immunoassay.RESULTS: Efficacy analyses included 97 patients (tozorakimab+SoC, n=53; SoC, n=44). Median time to clinical response did not differ between the tozorakimab and SoC arms (8.0 and 9.5 days, respectively; HR 0.96, 80% CI 0.70-1.31; one-sided p=0.33). Tozorakimab was well tolerated and the OR for risk of death or respiratory failure with treatment versus SoC was 0.55 (80% CI 0.27-1.12; p=0.26), while the OR was 0.31 (80% CI 0.09-1.06) in patents with high baseline serum IL-33/sST2 complex levels.CONCLUSIONS: Overall, ACCORD-2 results suggest that tozorakimab could be a novel therapy for patients hospitalised with COVID-19, warranting further investigation in confirmatory phase 3 studies.</p

    SPIRE - combining SGI-110 with cisplatin and gemcitabine chemotherapy for solid malignancies including bladder cancer: study protocol for a phase Ib/randomised IIa open label clinical trial

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    Background Urothelial bladder cancer (UBC) accounts for 10,000 new diagnoses and 5000 deaths annually in the UK (Cancer Research UK, http://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/bladder-cancer, Cancer Research UK, Accessed 26 Mar 2018). Cisplatin-based chemotherapy is standard of care therapy for UBC for both palliative first-line treatment of advanced/metastatic disease and radical neoadjuvant treatment of localised muscle invasive bladder cancer. However, cisplatin resistance remains a critical cause of treatment failure and a barrier to therapeutic advance in UBC. Based on supportive pre-clinical data, we hypothesised that DNA methyltransferase inhibition would circumvent cisplatin resistance in UBC and potentially other cancers. Methods The addition of SGI-110 (guadecitabine, a DNA methyltransferase inhibitor) to conventional doublet therapy of gemcitabine and cisplatin (GC) is being tested within the phase Ib/IIa SPIRE clinical trial. SPIRE incorporates an initial, modified rolling six-dose escalation phase Ib design of up to 36 patients with advanced solid tumours followed by a 20-patient open-label randomised controlled dose expansion phase IIa component as neoadjuvant treatment for UBC. Patients are being recruited from UK secondary care sites. The dose escalation phase will determine a recommended phase II dose (RP2D, primary endpoint) of SGI-110, by subcutaneous injection, on days 1–5 for combination with GC at conventional doses (cisplatin 70 mg/m2, IV infusion, day 8; gemcitabine 1000 mg/m2, IV infusion, days 8 and 15) in every 21-day cycle. In the dose expansion phase, patients will be randomised 1:1 to GC with or without SGI-110 at the proposed RP2D. Secondary endpoints will include toxicity profiles, SGI-110 pharmacokinetics and pharmacodynamic biomarkers, and pathological complete response rates in the dose expansion phase. Analyses will not be powered for formal statistical comparisons and descriptive statistics will be used to describe rates of toxicity, efficacy and translational endpoints by treatment arm. Discussion SPIRE will provide evidence for whether SGI-110 in combination with GC chemotherapy is safe and biologically effective prior to future phase II/III trials as a neoadjuvant therapy for UBC and potentially in other cancers treated with GC
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