67 research outputs found

    Role of liposome and peptide in the synergistic enhancement of transfection with a lipopolyplex vector

    Get PDF
    Lipopolyplexes are of widespread interest for gene therapy due to their multifunctionality and high transfection efficiencies. Here we compared the biological and biophysical properties of a lipopolyplex formulation with its lipoplex and polyplex equivalents to assess the role of the lipid and peptide components in the formation and function of the lipopolyplex formulation. We show that peptide efficiently packaged plasmid DNA forming spherical, highly cationic nanocomplexes that are taken up efficiently by cells. However, transgene expression was poor, most likely due to endosomal degradation since the polyplex lacks membrane trafficking properties. In addition the strong peptide-DNA interaction may prevent plasmid release from the complex and so limit plasmid DNA availability. Lipid/DNA lipoplexes, on the other hand, produced aggregated masses that showed poorer cellular uptake than the polyplex but contrastingly greater levels of transgene expression. This may be due to the greater ability of lipoplexes relative to polyplexes to promote endosomal escape. Lipopolyplex formulations formed spherical, cationic nanocomplexes with efficient cellular uptake and significantly enhanced transfection efficiency. The lipopolyplexes combined the optimal features of lipoplexes and polyplexes showing optimal cell uptake, endosomal escape and availability of plasmid for transcription, thus explaining the synergistic increase in transfection efficiency

    Urban heritages: how history and housing finance matter to housing form and homeownership rates

    Get PDF
    Contemporary Western cities are not uniform but display a variety of different housing forms and tenures, both between and within countries. We distinguish three general city types in this paper: low rise, single-family dwelling cities where owner-occupation is the most prevalent tenure form; multi-dwelling building cities where tenants comprise the majority and; multi-dwelling building cities where owner occupation is the principal tenure form. We argue that historical developments beginning in the nineteenth century are crucial to understanding this diversity in urban form and tenure composition across Western cities. Our path-dependent argument is twofold. First, we claim that different housing finance institutions engendered different forms of urban development during the late-nineteenth century and had helped to establish the difference between single-family dwelling cities and multi-dwelling building cities by 1914. Second, rather than stemming from countries’ welfare systems or ‘variety of capitalism’, we argue that these historical distinctions have a significant and enduring impact on today’s urban housing forms and tenures. Our argument is supported by a unique collection of data of 1095 historical cities across 27 countries

    Armed conflicts have an impact on the spread of tuberculosis: the case of the Somali Regional State of Ethiopia

    Get PDF
    <p>Abstract</p> <p/> <p>A pessimistic view of the impact of armed conflicts on the control of infectious diseases has generated great interest in the role of conflicts on the global TB epidemic. Nowhere in the world is such interest more palpable than in the Horn of Africa Region, comprising Ethiopia, Somalia, Eritrea, Djibouti, Kenya and Sudan. An expanding literature has demonstrated that armed conflicts stall disease control programs through distraction of health system, interruption of patients' ability to seek health care, and the diversion of economic resources to military ends rather than health needs. Nonetheless, until very recently, no research has been done to address the impact of armed conflict on TB epidemics in the Somali Regional State (SRS) of Ethiopia.</p> <p>Methods</p> <p>This study is based on the cross-sectional data collected in 2007, utilizing structured questionnaires filled-out by a sample of 226 TB patients in the SRS of Ethiopia. Data was obtained on the delay patients experienced in receiving a diagnosis of TB, on the biomedical knowledge of TB that patients had, and the level of self-treatment by patients. The outcome variables in this study are the delay in the diagnosis of TB experienced by patients, and extent of self-treatment utilized by patients. Our main explanatory variable was place of residence, which was dichotomized as being in 'conflict zones' and in 'non-conflict zones'. Demographic data was collected for statistical control. Chi-square and Mann-Whitney tests were used on calculations of group differences. Logistic regression analysis was used to determine the association between outcome and predictor variables.</p> <p>Results</p> <p>Two hundred and twenty six TB patients were interviewed. The median delay in the diagnosis of TB was 120 days and 60 days for patients from conflict zones and from non-conflict zones, respectively. Moreover, 74% of the patients residing in conflict zones undertook self-treatment prior to their diagnosis. The corresponding proportion from non-conflict zones was 45%. Fully adjusted logistic regression analysis shows that patients from conflict zones had significantly greater odds of delay (OR = 3.06; 95% CI: 1.47-6.36) and higher self treatment utilization (OR = 3.34; 95% CI: 1.56-7.12) compared to those from non-conflict zones.</p> <p>Conclusion</p> <p>Patients from conflict zones have a longer delay in receiving a diagnosis of TB and have higher levels of self treatment utilization. This suggests that access to TB care should be improved by the expansion of user friendly directly observed therapy short-course (DOTS) in the conflict zones of the region.</p

    Comparing multiple competing interventions in the absence of randomized trials using clinical risk-benefit analysis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>To demonstrate the use of risk-benefit analysis for comparing multiple competing interventions in the absence of randomized trials, we applied this approach to the evaluation of five anticoagulants to prevent thrombosis in patients undergoing orthopedic surgery.</p> <p>Methods</p> <p>Using a cost-effectiveness approach from a clinical perspective (i.e. risk benefit analysis) we compared thromboprophylaxis with warfarin, low molecular weight heparin, unfractionated heparin, fondaparinux or ximelagatran in patients undergoing major orthopedic surgery, with sub-analyses according to surgery type. Proportions and variances of events defining risk (major bleeding) and benefit (thrombosis averted) were obtained through a meta-analysis and used to define beta distributions. Monte Carlo simulations were conducted and used to calculate incremental risks, benefits, and risk-benefit ratios. Finally, net clinical benefit was calculated for all replications across a range of risk-benefit acceptability thresholds, with a reference range obtained by estimating the case fatality rate - ratio of thrombosis to bleeding.</p> <p>Results</p> <p>The analysis showed that compared to placebo ximelagatran was superior to other options but final results were influenced by type of surgery, since ximelagatran was superior in total knee replacement but not in total hip replacement.</p> <p>Conclusions</p> <p>Using simulation and economic techniques we demonstrate a method that allows comparing multiple competing interventions in the absence of randomized trials with multiple arms by determining the option with the best risk-benefit profile. It can be helpful in clinical decision making since it incorporates risk, benefit, and personal risk acceptance.</p

    Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

    Get PDF
    Background The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. Methods We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. Findings We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). Interpretation Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. Funding PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders

    A systematic review on the accumulation of prophylactic dosages of low-molecular-weight heparins (LMWHs) in patients with renal insufficiency

    Get PDF
    PURPOSE: Although therapeutic dosages of most low-molecular-weight heparins (LMWHs) are known to accumulate in patients with renal insufficiency, for the lower prophylactic dosages this has not been clearly proven. Nevertheless, dose reduction is often recommended. We conducted a systematic review to investigate whether prophylactic dosages of LMWH accumulate in renal insufficient patients. METHODS: A comprehensive search was conducted on 17 February 2015 using Embase, Medline, Web of Science, Scopus, Cochrane, PubMed publisher, and Google scholar. The syntax emphasized for LMWHs, impaired renal function, and pharmacokinetics. The search yielded 674 publications. After exclusion by reading the titles, abstracts, and if necessary the full paper, 11 publications remained. RESULTS: For dalteparin and tinzaparin, no accumulation was observed. Enoxaparin, on the other hand, did lead to accumulation in patients with renal insufficiency, although not in patients undergoing renal replacement therapy. Bemiparin and certoparin also did show accumulation. No data were available for nadroparin. CONCLUSIONS: In this systematic review, we show that prophylactic dosages of tinzaparin and dalteparin are likely to be safe in patients with renal insufficiency and do not need dose reduction based on the absence of accumulation. However, prophylactic dosages of enoxaparin, bemiparin, and certoparin did show accumulation in patients with a creatinine clearance (CrCl) below 30 ml/min, and therefore, dose reduction is required. The differences in occurrence of accumulation seem to depend on the mean molecular weight of LMWHs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00228-015-1880-5) contains supplementary material, which is available to authorized users

    Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

    Get PDF
    Background No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge. Methods The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing. Findings 2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7–9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46–0·99]), obesity (0·50 [0·34–0·74]) and invasive mechanical ventilation (0·42 [0·23–0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74–1·00]), at 5 months (0·74 [0·64–0·88]) to 1 year (0·75 [0·62–0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters. Interpretation The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials. Funding UK Research and Innovation and National Institute for Health Research
    corecore