136 research outputs found

    Sympathoinhibitory effect of statins in chronic heart failure

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    Contains fulltext : 89087.pdf (publisher's version ) (Closed access)OBJECTIVES: Increased (central) sympathetic activity is a key feature of heart failure and associated with worse prognosis. Animal studies suggest that statin therapy can reduce central sympathetic outflow. This study assessed statin effects on (central) sympathetic activity in human chronic heart failure (CHF) patients. METHODS: Sympathetic activity was measured in eight patients with CHF patients during 8 weeks after discontinuation and 4 weeks after restart of statin therapy by microneurography for direct muscle sympathetic nerve recording (MSNA) and measurement of arterial plasma norepinephrine concentrations. RESULTS: During discontinuation of statin therapy, MSNA was significantly increased (73 +/- 4 vs. 56 +/- 5 and 52 +/- 6 bursts/100 beats, p = 0.01). Burst frequency was significantly higher after statin discontinuation (42 +/- 3 burst/min without statin vs. 32 +/- 3 and 28 +/- 3 burst/min during statin therapy, p = 0.004). Mean normalized burst amplitude and total normalized MSNA were significantly higher after statin discontinuation (mean normalized burst amplitude 0.36 +/- 0.04 without statin vs. 0.29 +/- 0.04 and 0.22 +/- 0.04 during statin, p < 0.05; total normalized MSNA 15.70 +/- 2.78 without statin, vs. 9.28 +/- 1.41 and 6.56 +/- 1.83 during statin, p = 0.009). Arterial plasma norepinephrine levels and blood pressure were unaffected. INTERPRETATION: Statin therapy inhibits central sympathetic outflow in CHF patients, as measured by MSNA.1 april 201

    Hearing Ability with Age in Northern European Women: A New Web-Based Approach to Genetic Studies

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    Age-related hearing impairment (ARHI) affects 25–40% of individuals over the age of 65. Despite the high prevalence of this complex trait, ARHI is still poorly understood. We hypothesized that variance in hearing ability with age is largely determined by genetic factors. We collected audiologic data on females of Northern European ancestry and compared different audiogram representations. A web-based speech-to-noise ratio (SNR) hearing test was compared with pure-tone thresholds to see if we could determine accurately hearing ability on people at home and the genetic contribution to each trait compared. Volunteers were recruited from the TwinsUK cohort. Hearing ability was determined using pure-tone audiometry and a web-based hearing test. Different audiogram presentations were compared for age-correlation and reflection of audiogram shape. Using structural equation modelling based on the classical twin model the heritability of ARHI, as measured by the different phenotypes, was estimated and shared variance between the web-based SNR test and pure-tone audiometry determined using bivariate modelling. Pure-tone audiometric data was collected on 1033 older females (age: 41–86). 1970 volunteers (males and females, age: 18–85) participated in the SNR. In the comparison between different ARHI phenotypes the difference between the first two principle components (PC1–PC2) best represented ARHI. The SNR test showed a sensitivity and specificity of 89% and 80%, respectively, in comparison with pure-tone audiogram data. Univariate heritability estimates ranged from 0.70 (95% CI: 0.63–0.76) for (PC1–PC2) to 0.56 (95% CI: 0.48–0.63) for PC2. The genetic correlation of PC1–PC2 and SNR was −0.67 showing that the 2 traits share variances attributed to additive genetic factors. Hearing ability showed considerable heritability in our sample. We have shown that the SNR test provides a useful surrogate marker of hearing. This will enable a much larger sample to be collected at a fraction of the cost, facilitating future genetic association studies

    Identification of key genes for carcinogenic pathways associated with colorectal adenoma-to-carcinoma progression

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    Colorectal adenomas form a biologically and clinically distinct intermediate stage in development of colorectal cancer (CRC) from normal colon epithelium. Only 5% of adenomas progress into adenocarcinomas, indicating that malignant transformation requires other biological alterations than those involved in adenoma formation. The present study aimed to explore which cancer-related biological processes are affected during colorectal adenoma-to-carcinoma progression and to identify key genes within these pathways that can serve as tumor markers for malignant transformation. The activity of 12 cancer-related biological processes was compared between 37 colorectal adenomas and 31 adenocarcinomas, using the pathway analysis tool Gene Set Enrichment Analysis. Expression of six gene sets was significantly increased in CRCs compared to adenomas, representing chromosomal instability, proliferation, differentiation, invasion, stroma activation, and angiogenesis. In addition, 18 key genes were identified for these processes based on their significantly increased expression levels. For AURKA and PDGFRB, increased mRNA expression levels were verified at the protein level by immunohistochemical analysis of a series of adenomas and CRCs. This study revealed cancer-related biological processes whose activities are increased during malignant transformation and identified key genes which may be used as tumor markers to improve molecular characterization of colorectal tumors

    The Yeast Spore Wall Enables Spores to Survive Passage through the Digestive Tract of Drosophila

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    In nature, yeasts are subject to predation by flies of the genus Drosophila. In response to nutritional starvation Saccharomyces cerevisiae differentiates into a dormant cell type, termed a spore, which is resistant to many types of environmental stress. The stress resistance of the spore is due primarily to a spore wall that is more elaborate than the vegetative cell wall. We report here that S. cerevisiae spores survive passage through the gut of Drosophila melanogaster. Constituents of the spore wall that distinguish it from the vegetative cell wall are necessary for this resistance. Ascospores of the distantly related yeast Schizosaccharomyces pombe also display resistance to digestion by D. melanogaster. These results suggest that the primary function of the yeast ascospore is as a cell type specialized for dispersion by insect vectors

    Mycoplasma genitalium: An Emerging Cause of Sexually Transmitted Disease in Women

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    Mycoplasma genitalium is an emerging sexually transmitted pathogen implicated in urethritis in men and several inflammatory reproductive tract syndromes in women including cervicitis, pelvic inflammatory disease (PID), and infertility. This comprehensive review critically examines epidemiologic studies of M. genitalium infections in women with the goal of assessing the associations with reproductive tract disease and enhancing awareness of this emerging pathogen. Over 27,000 women from 48 published reports have been screened for M. genitalium urogenital infection in high- or low-risk populations worldwide with an overall prevalence of 7.3% and 2.0%, respectively. M. genitalium was present in the general population at rates between those of Chlamydia trachomatis and Neisseria gonorrhoeae. Considering more than 20 studies of lower tract inflammation, M. genitalium has been positively associated with urethritis, vaginal discharge, and microscopic signs of cervicitis and/or mucopurulent cervical discharge in seven of 14 studies. A consistent case definition of cervicitis is lacking and will be required for comprehensive understanding of these associations. Importantly, evidence for M. genitalium PID and infertility are quite convincing and indicate that a significant proportion of upper tract inflammation may be attributed to this elusive pathogen. Collectively, M. genitalium is highly prevalent in high- and low-risk populations, and should be considered an etiologic agent of select reproductive tract disease syndromes in women

    Injectable Materials for the Treatment of Myocardial Infarction and Heart Failure: The Promise of Decellularized Matrices

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    Cardiovascular disease continues to be the leading cause of death, suggesting that new therapies are needed to treat the progression of heart failure post-myocardial infarction. As cardiac tissue has a limited ability to regenerate itself, experimental biomaterial therapies have focused on the replacement of necrotic cardiomyocytes and repair of the damaged extracellular matrix. While acellular and cellular cardiac patches are applied surgically to the epicardial surface of the heart, injectable materials offer the prospective advantage of minimally invasive delivery directly into the myocardium to either replace the damaged extracellular matrix or to act as a scaffold for cell delivery. Cardiac-specific decellularized matrices offer the further advantage of being biomimetic of the native biochemical and structural matrix composition, as well as the potential to be autologous therapies. This review will focus on the requirements of an ideal scaffold for catheter-based delivery as well as highlight the promise of decellularized matrices as injectable materials for cardiac repair

    The Staphylococcus aureus RNome and Its Commitment to Virulence

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    Staphylococcus aureus is a major human pathogen causing a wide spectrum of nosocomial and community-associated infections with high morbidity and mortality. S. aureus generates a large number of virulence factors whose timing and expression levels are precisely tuned by regulatory proteins and RNAs. The aptitude of bacteria to use RNAs to rapidly modify gene expression, including virulence factors in response to stress or environmental changes, and to survive in a host is an evolving concept. Here, we focus on the recently inventoried S. aureus regulatory RNAs, with emphasis on those with identified functions, two of which are directly involved in pathogenicity

    Effects of Heavy Metals and Arbuscular Mycorrhiza on the Leaf Proteome of a Selected Poplar Clone: A Time Course Analysis

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    Arbuscular mycorrhizal (AM) fungi establish a mutualistic symbiosis with the roots of most plant species. While receiving photosynthates, they improve the mineral nutrition of the plant and can also increase its tolerance towards some pollutants, like heavy metals. Although the fungal symbionts exclusively colonize the plant roots, some plant responses can be systemic. Therefore, in this work a clone of Populus alba L., previously selected for its tolerance to copper and zinc, was used to investigate the effects of the symbiosis with the AM fungus Glomus intraradices on the leaf protein expression. Poplar leaf samples were collected from plants maintained in a glasshouse on polluted (copper and zinc contaminated) or unpolluted soil, after four, six and sixteen months of growth. For each harvest, about 450 proteins were reproducibly separated on 2DE maps. At the first harvest the most relevant effect on protein modulation was exerted by the AM fungi, at the second one by the metals, and at the last one by both treatments. This work demonstrates how importantly the time of sampling affects the proteome responses in perennial plants. In addition, it underlines the ability of a proteomic approach, targeted on protein identification, to depict changes in a specific pattern of protein expression, while being still far from elucidating the biological function of each protein

    MR fluoroscopy in vascular and cardiac interventions (review)

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    Vascular and cardiac disease remains a leading cause of morbidity and mortality in developed and emerging countries. Vascular and cardiac interventions require extensive fluoroscopic guidance to navigate endovascular catheters. X-ray fluoroscopy is considered the current modality for real time imaging. It provides excellent spatial and temporal resolution, but is limited by exposure of patients and staff to ionizing radiation, poor soft tissue characterization and lack of quantitative physiologic information. MR fluoroscopy has been introduced with substantial progress during the last decade. Clinical and experimental studies performed under MR fluoroscopy have indicated the suitability of this modality for: delivery of ASD closure, aortic valves, and endovascular stents (aortic, carotid, iliac, renal arteries, inferior vena cava). It aids in performing ablation, creation of hepatic shunts and local delivery of therapies. Development of more MR compatible equipment and devices will widen the applications of MR-guided procedures. At post-intervention, MR imaging aids in assessing the efficacy of therapies, success of interventions. It also provides information on vascular flow and cardiac morphology, function, perfusion and viability. MR fluoroscopy has the potential to form the basis for minimally invasive image–guided surgeries that offer improved patient management and cost effectiveness
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