246 research outputs found

    The inorganic NItrate and eXercise performance in Heart Failure (iNIX-HF) phase II clinical trial: Rationale and study design

    Get PDF
    BACKGROUND: Heart failure (HF) is a debilitating and often fatal disease that affects millions of people worldwide. Diminished nitric oxide synthesis, signaling, and bioavailability are believed to contribute to poor skeletal muscle function and aerobic capacity. The aim of this clinical trial (iNIX-HF) is to determine the acute and longer-term effectiveness of inorganic nitrate supplementation on exercise performance in patients with HF with reduced ejection fraction (HFrEF). METHODS: This clinical trial is a double-blind, placebo-controlled, randomized, parallel-arm design study in which patients with HFrEF (n = 75) are randomized to receive 10 mmol potassium nitrate (KNO DISCUSSION: The iNIX-HF phase II clinical trial will evaluate the effectiveness of inorganic nitrate supplements as a new treatment to ameliorate poor exercise capacity in HFrEF. This study also will provide critical preliminary data for a future \u27pivotal\u27, phase III, multi-center trial of the effectiveness of nitrate supplements not only for improving exercise performance, but also for improving symptoms and decreasing other major cardiovascular endpoints. The potential public health impact of identifying a new, relatively inexpensive, safe, and effective treatment that improves overall exercise performance in patients with HFrEF is significant

    Response of CsI(Tl) scintillators over a large range in energy and atomic number of ions (Part I): recombination and delta -- electrons

    Full text link
    A simple formalism describing the light response of CsI(Tl) to heavy ions, which quantifies the luminescence and the quenching in terms of the competition between radiative transitions following the carrier trapping at the Tl activator sites and the electron-hole recombination, is proposed. The effect of the delta rays on the scintillation efficiency is for the first time quantitatively included in a fully consistent way. The light output expression depends on four parameters determined by a procedure of global fit to experimental data.Comment: 28 pages, 6 figures, submitted to Nucl. Inst. Meth.

    Caloric curves and critical behavior in nuclei

    Get PDF
    Data from a number of different experimental measurements have been used to construct caloric curves for five different regions of nuclear mass. These curves are qualitatively similar and exhibit plateaus at the higher excitation energies. The limiting temperatures represented by the plateaus decrease with increasing nuclear mass and are in very good agreement with results of recent calculations employing either a chiral symmetry model or the Gogny interaction. This agreement strongly favors a soft equation of state. Evidence is presented that critical excitation energies and critical temperatures for nuclei can be determined over a large mass range when the mass variations inherent in many caloric curve measurements are taken into account.Comment: In response to referees comments we have improved the discussion of the figures and added a new figure showing the relationship between the effective level density and the excitation energy. The discussion has been reordered and comments are made on recent data which support the hypothesis of a mass dependence of caloric curve

    Association of functional polymorphisms from brain-derived neurotrophic factor and serotonin-related genes with depressive symptoms after a medical stressor in older adults

    Get PDF
    Depressive symptoms are common in older adults after a disabling medical event and interfere with rehabilitation and recovery from the disability. This prospective study examined the role of genetic polymorphisms implicated in synaptic integrity and stress-associated depression as predictors of depressive symptoms after hip fracture. We recruited healthy comparisons from the community and participants with hip fracture after surgical fixation from Saint Louis, Missouri hospitals. We examined the valine (Val) to methionine (Met) polymorphism in brain-derived neurotrophic factor (BDNF), serotonin 1A receptor (5HT1a-rs6295) polymorphism, and the serotonin transporter-linked polymorphic region (5HTTLPR) interaction with the rs25531 A to G single nucleotide polymorphism (5HTTLPR-rs25531) as predictors of depressive symptoms. We also examined whether depressive symptoms mediate the influence of BDNF genotype on functional recovery. Among 429 participants with hip fracture, BDNF Met/Met carriers developed significantly more depressive symptoms than Val/Val carriers during a four-week period after the fracture (p=.012). BDNF genotype also predicted functional recovery over the ensuing year, mediated by its effects on depressive symptoms (CI: 0.07-3.37). Unlike prior studies of stressful life events, the S' 5HTTLPR-rs25531 variant did not predict higher levels of depressive symptoms; instead, we report an exploratory finding of an epistatic effect between BDNF and 5HTTLPR-rs25531 whereby the compounded effects of two LA alleles and BDNF Met/Met genotype elevate risk of depressive symptoms after hip fracture (p=.006). No differences between 5HT1a genotypes were found. Our findings suggest plasticity-related genetic factors contribute to the neural mechanisms of mental and functional well-being after a disabling medical stressor

    Sequencing of the Hepatitis C Virus: A Systematic Review

    Get PDF
    Since the identification of hepatitis C virus (HCV), viral sequencing has been important in understanding HCV classification, epidemiology, evolution, transmission clustering, treatment response and natural history. The length and diversity of the HCV genome has resulted in analysis of certain regions of the virus, however there has been little standardisation of protocols. This systematic review was undertaken to map the location and frequency of sequencing on the HCV genome in peer reviewed publications, with the aim to produce a database of sequencing primers and amplicons to inform future research. Medline and Scopus databases were searched for English language publications based on keyword/MeSH terms related to sequence analysis (9 terms) or HCV (3 terms), plus "primer" as a general search term. Exclusion criteria included non-HCV research, review articles, duplicate records, and incomplete description of HCV sequencing methods. The PCR primer locations of accepted publications were noted, and purpose of sequencing was determined. A total of 450 studies were accepted from the 2099 identified, with 629 HCV sequencing amplicons identified and mapped on the HCV genome. The most commonly sequenced region was the HVR-1 region, often utilised for studies of natural history, clustering/transmission, evolution and treatment response. Studies related to genotyping/classification or epidemiology of HCV genotype generally targeted the 5'UTR, Core and NS5B regions, while treatment response/resistance was assessed mainly in the NS3-NS5B region with emphasis on the Interferon sensitivity determining region (ISDR) region of NS5A. While the sequencing of HCV is generally constricted to certain regions of the HCV genome there is little consistency in the positioning of sequencing primers, with the exception of a few highly referenced manuscripts. This study demonstrates the heterogeneity of HCV sequencing, providing a comprehensive database of previously published primer sets to be utilised in future sequencing studies

    Adrenal adenomatoid tumor in a patient with human immunodeficiency virus

    Get PDF
    We present the clinical course of a patient with human immunodeficiency virus and an adrenal adenomatoid tumor (AAT). We describe the clinical course and laboratory, radiographic, and microscopic findings of a patient with human immunodeficiency virus (HIV) and an adenomatoid tumor of the right adrenal gland. A review of the literature was also done via electronic searches through PubMed for articles from 1965 to 2008 that contained the following search terms, adenomatoid tumor limited to the English language only. A 22 year-old African-American male with HIV was incidentally found to have a hypermetabolic right adrenal mass. The patient underwent laparoscopic adrenalectomy and the mass had morphological and immunohistochemical features that were consistent with an AAT. A review of the medical literature reveals that almost all cases of AAT were in male patients (96%) with a mean age of 41±11 years (range=22–64) with no significant difference in laterality (right side=46%, left side=50%, unknown=4%). AAT have an average size of 4.2±3.5 cm (range=0.5–14.3 cm). Pre-operative imaging studies do not appear to be able to reliably distinguish AAT from other types of adrenocortical tumors. For reasons that require further research, AAT typically occur in male patients and may be associated with immunosuppression. AAT can be safely removed laparoscopically with no evidence of long-term recurrence even with tumor extension beyond the adrenal capsule

    Patterns of adiposity, vascular phenotypes and cognitive function in the 1946 British Birth Cohort.

    Get PDF
    BACKGROUND: The relationship between long-term exposure to whole body or central obesity and cognitive function, as well as its potential determinants, remain controversial. In this study, we assessed (1) the potential impact of 30 years exposure to different patterns of whole body and central adiposity on cognitive function at 60-64 years, (2) whether trajectories of central adiposity can provide additional information on later cognitive function compared to trajectories of whole body adiposity, and (3) the influence of vascular phenotypes on these associations. METHODS: The study included 1249 participants from the prospective cohort MRC National Survey of Health and Development. Body mass index (BMI), waist circumference (WC), and vascular (carotid intima-media thickness, carotid-femoral pulse wave velocity) and cognitive function (memory, processing speed, reaction time) data, at 60-64 years, were used to assess the associations between different patterns of adult WC or BMI (from 36 years of age) and late midlife cognitive performance, as well as the proportion of this association explained by cardiovascular phenotypes. RESULTS: Longer exposure to elevated WC was related to lower memory performance (p < 0.001 for both) and longer choice reaction time (p = 0.003). A faster gain of WC between 36 and 43 years of age was associated with the largest change in reaction time and memory test (P < 0.05 for all). Similar associations were observed when patterns of WC were substituted with patterns of BMI, but when WC and BMI were included in the same model, only patterns of WC remained significantly associated with cognitive function. Participants who dropped one BMI category and maintained a lower BMI had similar memory performance to those of normal weight during the whole follow-up. Conversely, those who dropped and subsequently regained one BMI category had a memory function similar to those with 30 years exposure to elevated BMI. Adjustment for vascular phenotypes, levels of cardiovascular risk factors, physical activity, education, childhood cognition and socioeconomic position did not affect these associations. CONCLUSIONS: Longer exposure to elevated WC or BMI and faster WC or BMI gains between 36 and 43 years are related to lower cognitive function at 60-64 years. Patterns of WC in adulthood could provide additional information in predicting late midlife cognitive function than patterns of BMI. The acquisition of an adverse cardiovascular phenotype associated with adiposity is unlikely to account for these relationships

    Chronic exposure to outdoor air pollution and diagnosed cardiovascular disease: meta-analysis of three large cross-sectional surveys

    Get PDF
    BACKGROUND: Higher exposure to outdoor air pollution is associated with increased cardiopulmonary deaths, but there is limited evidence about the association between outdoor air pollution and diagnosed cardiovascular disease. Our study aimed to estimate the size of the association between long term exposure to outdoor air pollution and prevalent cardiovascular disease. METHODS: We carried out a cross-sectional analysis of data on more than 19,000 white adults aged 45 and older who participated in three representative surveys of the English population in 1994, 1998 and 2003, examining the relationship between self-reported doctor-diagnosed cardiovascular disease and exposure to outdoor air pollutants using multilevel regression techniques and meta-analysis. RESULTS: The combined estimates suggested that an increase of 1 microg m-3 in concentration of particulate matter less than 10 microns in diameter was associated with an increase of 2.9% (95% CI -0.6% to 6.5%) in prevalence of cardiovascular disease in men, and an increase of 1.6% (95%CI -2.1% to 5.5%) in women. The year-specific analyses showed strongly positive associations in 2003 between odds of cardiovascular disease in both men and women and exposure to particulate matter but not in 1994 or 1998. We found no consistent associations between exposure to gaseous air pollutants and doctor-diagnosed cardiovascular disease. CONCLUSION: The associations of prevalent cardiovascular disease with concentration of particulate matter less than 10 microns in diameter, while only weakly positive, were consistent with the effects reported in cohort studies. The results provide evidence of the size of the association between particulate air pollution and the prevalence of cardiovascular disease but no evidence for an association with gaseous pollutants. We found strongly positive associations between particulate matter and cardiovascular disease in 2003 only, which highlights the importance of replicating findings in more than one population
    corecore