51 research outputs found
Hepatitis C Diagnosis and Treatment, Impact on Engagement and Behaviour of People Who Inject Drugs, a service evaluation, the Hooked C project
There is emerging evidence that Hepatitis C (HCV) treatment engagement is associated with change in drug behaviours and reduced drug-related death rates among people who inject drugs (PWID). The project aims to investigate whether HCV diagnosis and treatment engagement reduces all-cause mortality and drug-related death, and whether any effect is dependent on treatment regimen and intensity of engagement with staff. Case-control studies comparing: PWID with active HCV infection (PCR positive) to PWID HCV infected but spontaneously resolved (PCR negative); PCR-positive patients who engaged with treatment services to nonengagers; and patients who received interferon vs direct-acting antiviral (DAA) based treatment.
No differences in risk of all-cause mortality or drug-related death between PCR-negative controls and PCR-positive cases were detected. The odds of all-cause mortality was 12.2 times higher in nonengaging persons compared to treatment engaging cases (aOR 12.15, 95% CI 7.03-20.99, PÂ <Â .001). The odds of a drug-related death were 5.5 times higher in nonengaging persons compared with treatment engaging cases (aOR 5.52, 95% CI 2.67- 11.44, PÂ <Â .001). No differences in risk of all-cause mortality or drug-related death between interferon-treated cases and DAA-treated controls were detected. HCV treatment engagement is significantly protective against all-cause mortality and drug-related death. This engagement effect is independent of treatment regimen, with the introduction of DAA therapies not increasing risk of drug-related death, suggesting intensity of HCV therapy provider interaction is not an important factor
Tax compliance costs for the small business sector in South Africa — establishing a baseline
This study is part of an international research project (across four countries) which is evaluating and comparing tax
compliance costs affecting the small business sector. The primary objective of this empirical study was to measure the tax
compliance costs of small businesses in South Africa and to establish a baseline against which future studies and
enhancements to the tax system could be measured. The study also differentiated tax compliance activities from core
accounting activities in order to identify the managerial benefits of tax compliance. It also investigated whether various South
African small business tax concessions are perceived to be achieving their objective of relieving the tax compliance burden.
The study, conducted by means of an electronic survey, provided plausible estimates proving that tax compliance costs as
well as core accounting costs are regressive with respect to business size, with the compliance burden being heavier for
smaller businesses. The perception that managerial benefits exist was also established for the first time in South Africa.
Overall, small business tax concessions were perceived as being more complex than useful. A re-evaluation of these
concessions or the introduction of a truly simplified tax system for small businesses is considered desirable.https://www.business.unsw.edu.au/research/publications/atax-journalam2016StatisticsTaxatio
Determinants of internal tax compliance costs : evidence from South Africa
Being tax compliant generates costs and these costs affect small business tax compliance behaviour and contribution. This study uses multiple regression analyses to investigate the key drivers of small business’s internal tax compliance costs (hours spent internally on tax compliance activities). This will assist Revenue Services in understanding what factors (determinants) could increase a small business’s internal tax compliance costs and might assist in managing tax compliance behaviour and contribution. The results expose the significant determinants per tax type, enabling a comparison to be made across the different tax types. Overall, turnover is the variable that had the most significant influence on internal tax compliance costs (time) (as opposed to the number of employees, which had a significant effect only on the internal time spent on employees’ tax). The analysis confirmed that there is a higher proportional burden for smaller businesses in respect of internal income tax and employees’ compliance activities.http://www.journals.co.za/content/journalam2016StatisticsTaxatio
Understanding VPAC receptor family peptide binding and selectivity
The vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) receptors are key regulators of neurological processes. Despite recent structural data, a comprehensive understanding of peptide binding and selectivity among different subfamily receptors is lacking. Here, we determine structures of active, Gs-coupled, VIP-VPAC1R, PACAP27-VPAC1R, and PACAP27-PAC1R complexes. Cryo-EM structural analyses and molecular dynamics simulations (MDSs) reveal fewer stable interactions between VPAC1R and VIP than for PACAP27, more extensive dynamics of VIP interaction with extracellular loop 3, and receptor-dependent differences in interactions of conserved N-terminal peptide residues with the receptor core. MD of VIP modelled into PAC1R predicts more transient VIP-PAC1R interactions in the receptor core, compared to VIP-VPAC1R, which may underlie the selectivity of VIP for VPAC1R over PAC1R. Collectively, our work improves molecular understanding of peptide engagement with the PAC1R and VPAC1R that may benefit the development of novel selective agonists
Activation of the GLP-1 receptor by a non-peptidic agonist
Class B G-protein-coupled receptors are major targets for the treatment of chronic diseases, including diabetes and obesity1. Structures of active receptors reveal peptide agonists engage deep within the receptor core, leading to an outward movement of extracellular loop 3 and the tops of transmembrane helices 6 and 7, an inward movement of transmembrane helix 1, reorganization of extracellular loop 2 and outward movement of the intracellular side of transmembrane helix 6, resulting in G-protein interaction and activation2,3,4,5,6. Here we solved the structure of a non-peptide agonist, TT-OAD2, bound to the glucagon-like peptide-1 (GLP-1) receptor. Our structure identified an unpredicted non-peptide agonist-binding pocket in which reorganization of extracellular loop 3 and transmembrane helices 6 and 7 manifests independently of direct ligand interaction within the deep transmembrane domain pocket. TT-OAD2 exhibits biased agonism, and kinetics of G-protein activation and signalling that are distinct from peptide agonists. Within the structure, TT-OAD2 protrudes beyond the receptor core to interact with the lipid or detergent, providing an explanation for the distinct activation kinetics that may contribute to the clinical efficacy of this compound series. This work alters our understanding of the events that drive the activation of class B receptors
Glucagon-like peptide-1 and its class B G protein-coupled receptors: A long march to therapeutic successes
Theglucagon-likepeptide (GLP)-1receptor (GLP-1R) is a class B G protein-coupled receptor (GPCR) that mediates the action of GLP-1, a peptide hormone secretedfromthreemajor tissues inhumans,enteroendocrine L cells in the distal intestine, a cells in the pancreas, and the central nervous system, which exerts important actions useful in the management of type 2 diabetes mellitus and obesity, including glucose homeostasis and regulation of gastric motility and food intake. Peptidic analogs of GLP-1 have been successfully developed with enhanced bioavailability and pharmacological activity. Physiologic and biochemical studies with truncated, chimeric, and mutated peptides and GLP-1R variants, together with ligand-bound crystal structures of the extracellular domain and the first three-dimensional structures of the 7-helical transmembrane domain of class B GPCRs, have provided the basis for a twodomain-binding mechanism of GLP-1 with its cognate receptor. Although efforts in discovering therapeutically viable nonpeptidicGLP-1R agonists have been hampered, small-moleculemodulators offer complementary chemical tools to peptide analogs to investigate ligand-directed biased cellular signaling of GLP-1R. The integrated pharmacological and structural information of different GLP-1 analogs and homologous receptors give new insights into the molecular determinants of GLP-1R ligand selectivity and functional activity, thereby providing novel opportunities in the design and development of more efficacious agents to treat metabolic disorders
Refined histopathological predictors of BRCA1 and BRCA2 mutation status: A large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia
Introduction: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling. Methods: Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the
Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function
Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes
Cerebral microbleeds and intracranial haemorrhage risk in patients anticoagulated for atrial fibrillation after acute ischaemic stroke or transient ischaemic attack (CROMIS-2):a multicentre observational cohort study
Background:
Cerebral microbleeds are a potential neuroimaging biomarker of cerebral small vessel diseases that are prone to intracranial bleeding. We aimed to determine whether presence of cerebral microbleeds can identify patients at high risk of symptomatic intracranial haemorrhage when anticoagulated for atrial fibrillation after recent ischaemic stroke or transient ischaemic attack.
Methods:
Our observational, multicentre, prospective inception cohort study recruited adults aged 18 years or older from 79 hospitals in the UK and one in the Netherlands with atrial fibrillation and recent acute ischaemic stroke or transient ischaemic attack, treated with a vitamin K antagonist or direct oral anticoagulant, and followed up for 24 months using general practitioner and patient postal questionnaires, telephone interviews, hospital visits, and National Health Service digital data on hospital admissions or death. We excluded patients if they could not undergo MRI, had a definite contraindication to anticoagulation, or had previously received therapeutic anticoagulation. The primary outcome was symptomatic intracranial haemorrhage occurring at any time before the final follow-up at 24 months. The log-rank test was used to compare rates of intracranial haemorrhage between those with and without cerebral microbleeds. We developed two prediction models using Cox regression: first, including all predictors associated with intracranial haemorrhage at the 20% level in univariable analysis; and second, including cerebral microbleed presence and HAS-BLED score. We then compared these with the HAS-BLED score alone. This study is registered with ClinicalTrials.gov, number NCT02513316.
Findings:
Between Aug 4, 2011, and July 31, 2015, we recruited 1490 participants of whom follow-up data were available for 1447 (97%), over a mean period of 850 days (SD 373; 3366 patient-years). The symptomatic intracranial haemorrhage rate in patients with cerebral microbleeds was 9·8 per 1000 patient-years (95% CI 4·0–20·3) compared with 2·6 per 1000 patient-years (95% CI 1·1–5·4) in those without cerebral microbleeds (adjusted hazard ratio 3·67, 95% CI 1·27–10·60). Compared with the HAS-BLED score alone (C-index 0·41, 95% CI 0·29–0·53), models including cerebral microbleeds and HAS-BLED (0·66, 0·53–0·80) and cerebral microbleeds, diabetes, anticoagulant type, and HAS-BLED (0·74, 0·60–0·88) predicted symptomatic intracranial haemorrhage significantly better (difference in C-index 0·25, 95% CI 0·07–0·43, p=0·0065; and 0·33, 0·14–0·51, p=0·00059, respectively).
Interpretation:
In patients with atrial fibrillation anticoagulated after recent ischaemic stroke or transient ischaemic attack, cerebral microbleed presence is independently associated with symptomatic intracranial haemorrhage risk and could be used to inform anticoagulation decisions. Large-scale collaborative observational cohort analyses are needed to refine and validate intracranial haemorrhage risk scores incorporating cerebral microbleeds to identify patients at risk of net harm from oral anticoagulation.
Funding:
The Stroke Association and the British Heart Foundation
Protective parents and permissive children: what qualitative interviews with parents and children can tell us about the feasibility of juvenile idiopathic arthritis trials
Background: Patient recruitment can be very challenging in paediatric studies, especially in relatively uncommon conditions, such as juvenile idiopathic arthritis (JIA). However, involving children and young people (CYP) in the design of such trials could promise a more rapid trajectory towards making evidence-based treatments available. Studies involving CYP are advocated in the literature but we are not aware of any early stage feasibility studies that have qualitatively accessed the perspectives of parents and CYP with a long term condition to inform design and conduct of a trial. In the context of a feasibility study to inform the design of a proposed randomised controlled trial of corticosteroid induction regimen in JIA, we explored families’ perspectives on the proposed trial and on JIA trials generally.
Methods: We analysed interviews with 27 participants (8 CYP aged 8–16 years and 19 parents) from four UK paediatric rheumatology centres. CYP had recently received corticosteroids to treat JIA. Audio-recorded interviews were transcribed and analysed thematically, drawing on the Framework Method.
Results: Both parents and CYP were capable of engaging with the logic of the proposed trial but pointed to challenges with its design. Treatment preferences influenced willingness to participate in the proposed trial. The preferences of older children and their parents often differed, with CYP being more willing to participate in the proposed trial than parents. Families’ current treatment preferences were largely informed by past positive and negative treatment experiences. Some participants also indicated that their treatment preferences were influenced by those of their clinicians.
Conclusion: Previous research has typically focused on deficits in patients’ understandings of trials. We found that both parents and CYP understood trial concepts and were able to identify potential flaws in the proposed trial. We propose recommendations to optimise the design of a planned corticosteroid induction regimen trial in JIA. Accessing both parents’ and CYP’s perspectives helps to identify and address recruitment challenges, which will ultimately optimise informed consent and future recruitment
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