694 research outputs found

    The use of Macitentan in Fontan circulation: a case report.

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    BACKGROUND: The Fontan circulation, a result of a palliative procedure in patients with single systemic ventricles, is defined by chronically elevated pulmonary vascular resistance. When traditional heart failure therapies fail, pharmacological agents that reduce pulmonary artery pressures may be used. These include endothelial-receptor antagonists, prostanoids and phosphodiesterase type 5 inhibitors. We report the first use of macitentan, an endothelin-receptor antagonist, in a patient with a Fontan circulation. CASE PRESENTATION: We describe the case of a 50 year old female with tricuspid atresia and transposition of the great arteries. Following complex surgery as a child, she subsequently underwent a fenestrated modified atrial pulmonary Fontan operation which was later converted to a total cavopulmonary anastomosis Fontan circulation. Due to failure of various medications to relieve her worsening symptoms, she was commenced on macitentan in April 2016. Few months later, she demonstrated a significant symptomatic improvement and associated increase in her incremental shuttle walking test distance. CONCLUSIONS: Macitentan has slower receptor dissociation kinetics compared to other endothelin-receptor antagonists, leading to enhanced pharmacological activity with promising effects in patients with pulmonary arterial hypertension. The patient we report has shown considerable improvement in exercise capacity following introduction of this medication and thus we suggest further randomised trials to establish the role of different endothelin-receptor antagonists in the management of the Fontan circulation

    Haptoglobin Phenotype, Preeclampsia Risk and the Efficacy of Vitamin C and E Supplementation to Prevent Preeclampsia in a Racially Diverse Population

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    Haptoglobin's (Hp) antioxidant and pro-angiogenic properties differ between the 1-1, 2-1, and 2-2 phenotypes. Hp phenotype affects cardiovascular disease risk and treatment response to antioxidant vitamins in some non-pregnant populations. We previously demonstrated that preeclampsia risk was doubled in white Hp 2-1 women, compared to Hp 1-1 women. Our objectives were to determine whether we could reproduce this finding in a larger cohort, and to determine whether Hp phenotype influences lack of efficacy of antioxidant vitamins in preventing preeclampsia and serious complications of pregnancy-associated hypertension (PAH). This is a secondary analysis of a randomized controlled trial in which 10,154 low-risk women received daily vitamin C and E, or placebo, from 9-16 weeks gestation until delivery. Hp phenotype was determined in the study prediction cohort (n = 2,393) and a case-control cohort (703 cases, 1,406 controls). The primary outcome was severe PAH, or mild or severe PAH with elevated liver enzymes, elevated serum creatinine, thrombocytopenia, eclampsia, fetal growth restriction, medically indicated preterm birth or perinatal death. Preeclampsia was a secondary outcome. Odds ratios were estimated by logistic regression. Sampling weights were used to reduce bias from an overrepresentation of women with preeclampsia or the primary outcome. There was no relationship between Hp phenotype and the primary outcome or preeclampsia in Hispanic, white/other or black women. Vitamin supplementation did not reduce the risk of the primary outcome or preeclampsia in women of any phenotype. Supplementation increased preeclampsia risk (odds ratio 3.30; 95% confidence interval 1.61-6.82, p<0.01) in Hispanic Hp 2-2 women. Hp phenotype does not influence preeclampsia risk, or identify a subset of women who may benefit from vitamin C and E supplementation to prevent preeclampsia

    A study of patient attitudes towards decentralisation of HIV care in an urban clinic in South Africa

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    <p>Abstract</p> <p>Background</p> <p>In South Africa, limited human resources are a major constraint to achieving universal antiretroviral therapy (ART) coverage. Many of the public-sector HIV clinics operating within tertiary facilities, that were the first to provide ART in the country, have reached maximum patient capacity. Decentralization or "down-referral" (wherein ART patients deemed stable on therapy are referred to their closest Primary Health Clinics (PHCs) for treatment follow-up) is being used as a possible alternative of ART delivery care. This cross-sectional qualitative study investigates attitudes towards down-referral of ART delivery care among patients currently receiving care in a centralized tertiary HIV clinic.</p> <p>Methods</p> <p>Ten focus group discussions (FGDs) with 76 participants were conducted in early 2008 amongst ART patients initiated and receiving care for more than 3 months in the tertiary HIV clinic study site. Eligible individuals were invited to participate in FGDs involving 6-9 participants, and lasting approximately 1-2 hours. A trained moderator used a discussion topic guide to investigate the main issues of interest including: advantages and disadvantages of down-referral, potential motivating factors and challenges of down-referral, assistance needs from the transferring clinic as well as from PHCs.</p> <p>Results</p> <p>Advantages include closeness to patients' homes, transport and time savings. However, patients favour a centralized service for the following reasons: less stigma, patients established relationship with the centralized clinic, and availability of ancillary services. Most FGDs felt that for down-referral to occur there needed to be training of nurses in patient-provider communication.</p> <p>Conclusion</p> <p>Despite acknowledging the down-referral advantages of close proximity and lower transport costs, many participants expressed concerns about lack of trained HIV clinical staff, negative patient interactions with nurses, limited confidentiality and stigma. There was consensus that training of nurses and improved health systems at the local clinics were needed if successful down-referral was to take place.</p

    Rituximab in B-Cell Hematologic Malignancies: A Review of 20 Years of Clinical Experience

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    Rituximab is a human/murine, chimeric anti-CD20 monoclonal antibody with established efficacy, and a favorable and well-defined safety profile in patients with various CD20-expressing lymphoid malignancies, including indolent and aggressive forms of B-cell non-Hodgkin lymphoma. Since its first approval 20 years ago, intravenously administered rituximab has revolutionized the treatment of B-cell malignancies and has become a standard component of care for follicular lymphoma, diffuse large B-cell lymphoma, chronic lymphocytic leukemia, and mantle cell lymphoma. For all of these diseases, clinical trials have demonstrated that rituximab not only prolongs the time to disease progression but also extends overall survival. Efficacy benefits have also been shown in patients with marginal zone lymphoma and in more aggressive diseases such as Burkitt lymphoma. Although the proven clinical efficacy and success of rituximab has led to the development of other anti-CD20 monoclonal antibodies in recent years (e.g., obinutuzumab, ofatumumab, veltuzumab, and ocrelizumab), rituximab is likely to maintain a position within the therapeutic armamentarium because it is well established with a long history of successful clinical use. Furthermore, a subcutaneous formulation of the drug has been approved both in the EU and in the USA for the treatment of B-cell malignancies. Using the wealth of data published on rituximab during the last two decades, we review the preclinical development of rituximab and the clinical experience gained in the treatment of hematologic B-cell malignancies, with a focus on the well-established intravenous route of administration. This article is a companion paper to A. Davies, et al., which is also published in this issue

    What are emergency ambulance services doing to meet the needs of people who call frequently? A national survey of current practice in the United Kingdom

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    Background Emergency ambulance services are integral to providing a service for those with unplanned urgent and life-threatening health conditions. However, high use of the service by a small minority of patients is a concern. Our objectives were to describe: service-wide and local policies or pathways for people classified as Frequent Caller; call volume; and results of any audit or evaluation. Method We conducted a national survey of current practice in ambulance services in relation to the management of people who call the emergency ambulance service frequently using a structured questionnaire for completion by email and telephone interview. We analysed responses using a descriptive and thematic approach. Results Twelve of 13 UK ambulance services responded. Most services used nationally agreed definitions for ‘Frequent Caller’, with 600–900 people meeting this classification each month. Service-wide policies were in place, with local variations. Models of care varied from within-service care where calls are flagged in the call centre; contact made with callers; and their General Practitioner (GP) with an aim of discouraging further calls, to case management through cross-service, multi-disciplinary team meetings aiming to resolve callers’ needs. Although data were available related to volume of calls and number of callers meeting the threshold for definition as Frequent Caller, no formal audits or evaluations were reported. Conclusions Ambulance services are under pressure to meet challenging response times for high acuity patients. Tensions are apparent in the provision of care to patients who have complex needs and call frequently. Multi-disciplinary case management approaches may help to provide appropriate care, and reduce demand on emergency services. However, there is currently inadequate evidence to inform commissioning, policy or practice development

    Modelling the Health Impact of an English Sugary Drinks Duty at National and Local Levels

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    Increasing evidence associates excess refined sugar intakes with obesity, Type 2 diabetes and heart disease. Worryingly, the estimated volume of sugary drinks purchased in the UK has more than doubled between 1975 and 2007, from 510ml to 1140ml per person per week. We aimed to estimate the potential impact of a duty on sugar sweetened beverages (SSBs) at a local level in England, hypothesising that a duty could reduce obesity and related diseases. Methods and Findings We modelled the potential impact of a 20% sugary drinks duty on local authorities in England between 2010 and 2030. We synthesised data obtained from the British National Diet and Nutrition Survey (NDNS), drinks manufacturers, Office for National Statistics, and from previous studies. This produced a modelled population of 41 million adults in 326 lower tier local authorities in England. This analysis suggests that a 20% SSB duty could result in approximately 2,400 fewer diabetes cases, 1,700 fewer stroke and coronary heart disease cases, 400 fewer cancer cases, and gain some 41,000 Quality Adjusted Life Years (QALYs) per year across England. The duty might have the biggest impact in urban areas with young populations. Conclusions This study adds to the growing body of evidence suggesting health benefits for a duty on sugary drinks. It might also usefully provide results at an area level to inform local price interventions in England

    Manganese hexacyanomanganate open framework as a high-capacity positive electrode material for sodium-ion batteries

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    Potential applications of sodium-ion batteries in grid-scale energy storage, portable electronics and electric vehicles have revitalized research interest in these batteries. However, the performance of sodium-ion electrode materials has not been competitive with that of lithium-ion electrode materials. Here we present sodium manganese hexacyanomanganate (Na2MnII[Mn-II(CN)(6)]), an open-framework crystal structure material, as a viable positive electrode for sodium-ion batteries. We demonstrate a high discharge capacity of 209 mAh g(-1) at C/5 (40 mA g(-1)) and excellent capacity retention at high rates in a propylene carbonate electrolyte. We provide chemical and structural evidence for the unprecedented storage of 50% more sodium cations than previously thought possible during electrochemical cycling. These results represent a step forward in the development of sodium-ion batteries.open212

    Snow Control - An RCT protocol for a web-based self-help therapy to reduce cocaine consumption in problematic cocaine users

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    Background: Cocaine use has increased in most European countries, including Switzerland, and many states worldwide. The international literature has described treatment models that target the general population. In addition to supplying informative measures at the level of primary and secondary prevention, the literature also offers web-based self-help tools for problematic substance users, which is in line with tertiary prevention. Such programs, however, have been primarily tested on individuals with problematic alcohol and cannabis consumption, but not on cocaine-dependent individuals. Methods/Design: This paper presents the protocol of a randomised clinical trial to test the effectiveness of a web-based self-help therapy to reduce cocaine use in problematic cocaine users. The primary outcome is severity of cocaine dependence. Secondary outcome measures include cocaine craving, consumption of cocaine and other substances of abuse in the past month, and changes in depression characteristics. The therapy group will receive a 6-week self-help therapy to reduce cocaine consumption based on methods of Cognitive Behavioural Therapy, principles of Motivational Interviewing and self-control practices. The control group will be presented weekly psycho-educative information with a quiz. The predictive validity of participant characteristics on treatment retention and outcome will be explored. Discussion: To the best of our knowledge, this will be the first randomised clinical trial to test the effectiveness of online self-help therapy to reduce or abstain from cocaine use. It will also investigate predictors of outcome and retention. This trial is registered at Current Controlled Trials and is traceable as NTR-ISRCTN93702927

    Reproducibility of exhaled nitric oxide in smokers and non-smokers: relevance for longitudinal studies

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    <p>Abstract</p> <p>Background</p> <p>Currently, there is much interest in measuring fractional exhaled nitric oxide (<b>FE<sub>NO</sub></b>) in populations. We evaluated the reproducibility of <b>FE<sub>NO </sub></b>in healthy subjects and determined the number of subjects necessary to carry out a longitudinal survey of <b>FE<sub>NO </sub></b>in a population containing smokers and non-smokers, based on the assessed reproducibility.</p> <p>Methods</p> <p>The reproducibility of <b>FE<sub>NO </sub></b>was examined in 18 healthy smokers and 21 non-smokers. <b>FE<sub>NO </sub></b>was assessed once at 9 AM on five consecutive days; in the last day this measurement was repeated at 2 PM. Respiratory symptoms and medical history were assessed by questionnaire. The within- and between-session repeatability of <b>FE<sub>NO </sub></b>and log-transformed <b>FE<sub>NO </sub></b>was described. The power of a longitudinal study based on a relative increase in <b>FE<sub>NO </sub></b>was estimated using a bilateral t-test of the log-transformed <b>FE<sub>NO </sub></b>using the between-session variance of the assay.</p> <p>Results</p> <p><b>FE<sub>NO </sub></b>measurements were highly reproducible throughout the study. <b>FE<sub>NO </sub></b>was significantly higher in males than females regardless of smoking status. <b>FE<sub>NO </sub></b>was positively associated with height (p < 0.001), gender (p < 0.034), smoking (p < 0.0001) and percent FEV<sub>1</sub>/FVC (p < 0.001) but not with age (p = 0.987). The between-session standard deviation was roughly constant on the log scale. Assuming the between-session standard deviation is equal to its longitudinal equivalent, either 111 or 29 subjects would be necessary to achieve an 80% power in detecting a 3% or a 10% increase in <b>FE<sub>NO </sub></b>respectively.</p> <p>Conclusion</p> <p>The good reproducibility of <b>FE<sub>NO </sub></b>is not influenced by gender or smoking habits. In a well controlled, longitudinal study it should allow detecting even small increases in <b>FE<sub>NO </sub></b>with a reasonable population size.</p
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