454 research outputs found

    The Role of Aldosterone Blockade in Patients with Heart Failure

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    The mechanisms associated with aldosterone production both systemically and locally as well as the effects of aldosterone blockade on the pathophysiology of heart failure (HF) have been extensively reviewed in this series and elsewhere. This article will review the clinical evidence supporting the use of aldosterone blocking agents (AB)in patients with HF and speculate on some potential future uses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45819/1/10741_2005_Article_2352.pd

    Social functioning and behaviour in Mucopolysaccharidosis IH [Hurlers Syndrome]

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    Background: Mucopolysaccharidosis type IH (MPS-IH) [Hurlers Syndrome] is a developmental genetic disorder characterised by severe physical symptoms and cognitive decline. This study aimed to investigate the behavioural phenotype of MPS-IH treated by haematopoietic cell transplantation, focusing on social functioning and sleep. Parental stress was also measured. Methods: Participants were 22 children with MPS-IH (mean age 9 years 1 month), of whom 10 were male (45%). Parents completed the Social Responsiveness Scale (SRS), Child Behaviour Checklist (CBCL), Children’s Sleep Habit Questionnaire and Parent Stress Index, Short Form (PSI-SF). Results: Twenty-three per cent of children with MPS-IH scored in the severe range of the SRS, suggesting significant difficulties in social functioning. Children with MPS-IH were more than 30 times more likely to receive scores in the severe range than typically developing children. Thirty-six per cent scored in the mild-to-moderate range, suggesting milder, but marked, difficulties in social interaction. Although children with MPS-IH did not show significantly higher rates of internalising, externalising or total behaviour problems than the normative sample, they received scores that were significantly higher on social, thought and attention problems and rule-breaking behaviour, and all the competence areas of the CBCL. Parents of children with MPS-IH did not score significantly higher on parental stress than parents in a normative sample. Conclusions: Parents of children with MPS-IH rate their children as having problems with social functioning and various areas of competence more frequently than previously thought, with implications for clinical support

    Rationale, design and population baseline characteristics of the PERFORM Vascular Project: an ancillary study of the Prevention of cerebrovascular and cardiovascular Events of ischemic origin with teRutroban in patients with a history oF ischemic strOke or tRansient ischeMic attack (PERFORM) trial

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    <p><b>Purpose</b></p> <p>PERFORM is exploring the efficacy of terutroban versus aspirin for secondary prevention in patients with a history of ischemic stroke or transient ischemic attacks (TIAs). The PERFORM Vascular Project will evaluate the effect of terutroban on progression of atherosclerosis, as assessed by change in carotid intima-media thickness (CIMT) in a subgroup of patients.</p> <p><b>Methods and results</b></p> <p>The Vascular Project includes structural (CIMT, carotid plaques) and functional (carotid stiffness) vascular studies in all patients showing at least one carotid plaque at entry. Expected mean follow-up is 36 months. Primary endpoint is rate of change of CIMT. Secondary endpoints include emergent plaques and assessment of carotid stiffness. 1,100 patients are required for 90% statistical power to detect treatment-related CIMT difference of 0.025 mm. The first patient was randomized in April 2006.</p> <p><b>Conclusions</b></p> <p>The PERFORM Vascular Project will investigate terutroban’s effect on vascular structure and function in patients with a history of ischemic stroke or TIAs.</p&gt

    Exploring the Complexity of the HIV-1 Fitness Landscape

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    Although fitness landscapes are central to evolutionary theory, so far no biologically realistic examples for large-scale fitness landscapes have been described. Most currently available biological examples are restricted to very few loci or alleles and therefore do not capture the high dimensionality characteristic of real fitness landscapes. Here we analyze large-scale fitness landscapes that are based on predictive models for in vitro replicative fitness of HIV-1. We find that these landscapes are characterized by large correlation lengths, considerable neutrality, and high ruggedness and that these properties depend only weakly on whether fitness is measured in the absence or presence of different antiretrovirals. Accordingly, adaptive processes on these landscapes depend sensitively on the initial conditions. While the relative extent to which mutations affect fitness on their own (main effects) or in combination with other mutations (epistasis) is a strong determinant of these properties, the fitness landscape of HIV-1 is considerably less rugged, less neutral, and more correlated than expected from the distribution of main effects and epistatic interactions alone. Overall this study confirms theoretical conjectures about the complexity of biological fitness landscapes and the importance of the high dimensionality of the genetic space in which adaptation takes place

    Genotype to phenotype mapping and the fitness landscape of the E. coli lac promoter

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    Genotype-to-phenotype maps and the related fitness landscapes that include epistatic interactions are difficult to measure because of their high dimensional structure. Here we construct such a map using the recently collected corpora of high-throughput sequence data from the 75 base pairs long mutagenized E. coli lac promoter region, where each sequence is associated with its phenotype, the induced transcriptional activity measured by a fluorescent reporter. We find that the additive (non-epistatic) contributions of individual mutations account for about two-thirds of the explainable phenotype variance, while pairwise epistasis explains about 7% of the variance for the full mutagenized sequence and about 15% for the subsequence associated with protein binding sites. Surprisingly, there is no evidence for third order epistatic contributions, and our inferred fitness landscape is essentially single peaked, with a small amount of antagonistic epistasis. There is a significant selective pressure on the wild type, which we deduce to be multi-objective optimal for gene expression in environments with different nutrient sources. We identify transcription factor (CRP) and RNA polymerase binding sites in the promotor region and their interactions without difficult optimization steps. In particular, we observe evidence for previously unexplored genetic regulatory mechanisms, possibly kinetic in nature. We conclude with a cautionary note that inferred properties of fitness landscapes may be severely influenced by biases in the sequence data

    The captopril-digoxin multicenter resarch group study on the comparative steps of captopril and digoxin in patients with mildmoderate heart failure: Implications for therapy

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    It is argued that the basis of therapy in a patient with mild-to-moderate congestive heart failure should be a combination of a diuretic and a converting enzyme inhibitor, with the further addition of digoxin if necessary.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44603/1/10557_2005_Article_BF01881521.pd

    Audit of therapeutic interventions in inpatient children using two scores: are they evidence-based in developing countries?

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    BACKGROUND: The evidence base of clinical interventions in paediatric hospitals of developing countries has not been formally assessed. We performed this study to determine the proportion of evidence-based therapeutic interventions in a paediatric referral hospital of a developing country METHODS: The medical records of 167 patients admitted in one-month period were revised. Primary diagnosis and primary therapeutic interventions were determined for each patient. A systematic search was performed to assess the level of evidence for each intervention. Therapeutic interventions were classified using the Ellis score and the Oxford Centre for Evidence Based Medicine Levels of Evidence RESULTS: Any dehydration due to diarrhoea (59 cases) and pneumonia (42 cases) were the most frequent diagnoses. Based on Ellis score, level I evidence supported the primary therapeutic intervention in 21%, level II in 73% and level III in 6% cases. Using the Oxford classification 16%, 8%, 1% and 75% therapeutic interventions corresponded to grades A, B, C, and D recommendations, respectively. Overall, according to Ellis score, 94% interventions were evidence based. However, out of the total, 75% interventions were based on expert opinion or basic sciences. Most children with mild to moderate dehydration (52 cases) were inappropriately treated with slow intravenous fluids, and most children with non-complicated community acquired pneumonia (42 cases) received intravenous antibiotics CONCLUSIONS: Most interventions were inappropriate, despite the availability of effective therapy for several of them. Diarrhoeal dehydration and community acquired pneumonia were the most common diagnoses and were inappropriately managed. Existing effective interventions for dehydration and pneumonia need to be put into practice at referral hospitals of developing countries. For the remaining problems, there is the need to conduct appropriate clinical studies. Caution must be taken when assigning the level of evidence supporting therapeutic interventions, as commonly used classifications may be misleadin

    Effect of eplerenone on parathyroid hormone levels in patients with primary hyperparathyroidism: a randomized, double-blind, placebo-controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Increasing evidence suggests the bidirectional interplay between parathyroid hormone and aldosterone as an important mechanism behind the increased risk of cardiovascular damage and bone disease observed in primary hyperparathyroidism. Our primary object is to assess the efficacy of the mineralocorticoid receptor-blocker eplerenone to reduce parathyroid hormone secretion in patients with parathyroid hormone excess.</p> <p>Methods/design</p> <p>Overall, 110 adult male and female patients with primary hyperparathyroidism will be randomly assigned to eplerenone (25 mg once daily for 4 weeks and 4 weeks with 50 mg once daily after dose titration] or placebo, over eight weeks. Each participant will undergo detailed clinical assessment, including anthropometric evaluation, 24-h ambulatory arterial blood pressure monitoring, echocardiography, kidney function and detailed laboratory determination of biomarkers of bone metabolism and cardiovascular disease.</p> <p>The study comprises the following exploratory endpoints: mean change from baseline to week eight in (1) parathyroid hormone(1–84) as the primary endpoint and (2) 24-h systolic and diastolic ambulatory blood pressure levels, NT-pro-BNP, biomarkers of bone metabolism, 24-h urinary protein/albumin excretion and echocardiographic parameters reflecting systolic and diastolic function as well as cardiac dimensions, as secondary endpoints.</p> <p>Discussion</p> <p>In view of the reciprocal interaction between aldosterone and parathyroid hormone and the potentially ensuing target organ damage, the EPATH trial is designed to determine whether eplerenone, compared to placebo, will effectively impact on parathyroid hormone secretion and improve cardiovascular, renal and bone health in patients with primary hyperparathyroidism.</p> <p>Trial registration</p> <p>ISRCTN33941607</p

    C. elegans Germ Cells Show Temperature and Age-Dependent Expression of Cer1, a Gypsy/Ty3-Related Retrotransposon

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    Virus-like particles (VLPs) have not been observed in Caenorhabditis germ cells, although nematode genomes contain low numbers of retrotransposon and retroviral sequences. We used electron microscopy to search for VLPs in various wild strains of Caenorhabditis, and observed very rare candidate VLPs in some strains, including the standard laboratory strain of C. elegans, N2. We identified the N2 VLPs as capsids produced by Cer1, a retrotransposon in the Gypsy/Ty3 family of retroviruses/retrotransposons. Cer1 expression is age and temperature dependent, with abundant expression at 15°C and no detectable expression at 25°C, explaining how VLPs escaped detection in previous studies. Similar age and temperature-dependent expression of Cer1 retrotransposons was observed for several other wild strains, indicating that these properties are common, if not integral, features of this retroelement. Retrotransposons, in contrast to DNA transposons, have a cytoplasmic stage in replication, and those that infect non-dividing cells must pass their genomic material through nuclear pores. In most C. elegans germ cells, nuclear pores are largely covered by germline-specific organelles called P granules. Our results suggest that Cer1 capsids target meiotic germ cells exiting pachytene, when free nuclear pores are added to the nuclear envelope and existing P granules begin to be removed. In pachytene germ cells, Cer1 capsids concentrate away from nuclei on a subset of microtubules that are exceptionally resistant to microtubule inhibitors; the capsids can aggregate these stable microtubules in older adults, which exhibit a temperature-dependent decrease in egg viability. When germ cells exit pachytene, the stable microtubules disappear and capsids redistribute close to nuclei that have P granule-free nuclear pores. This redistribution is microtubule dependent, suggesting that capsids that are released from stable microtubules transfer onto new, dynamic microtubules to track toward nuclei. These studies introduce C. elegans as a model to study the interplay between retroelements and germ cell biology
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