3,199 research outputs found
Prevalence of varicose veins and chronic venous insufficiency of the legs in the general population
Chronic venous insufficiency: Clinical and duplex correlations. The Edinburgh Vein Study of venous disorders in the general population
AbstractObjective: The objective of this study was to determine the prevalence of chronic venous insufficiency (CVI) in the general population and to correlate its clinical features with sonographically proven venous reflux. Design of Study: The study design was a cross-sectional survey of the general population. Subjects and Method: Ambulatory men and women, aged 18-64 years, were selected randomly from 12 general practices. Subjects were examined for CVI. Eight segments of the deep and superficial veins were assessed for reflux by means of duplex scanning. Results: A total of 1566 subjects were screened (867 women, mean age 44.8 years; 699 men, mean age 45.8 years) of whom 124 were diagnosed as having CVI: 95, grade 1; 19, grade 2; and 10, grade 3. The age-adjusted prevalence for the whole population was 9.4% in men and 6.6% in women. Prevalence of CVI correlated closely with age and sex, being 21.2% in men >50 years and 12.0% in women >50 years. Heaviness and tension, and a feeling of swelling, aching, and itching, were significantly associated with worsening grade of CVI. CVI was significantly associated with reflux in all deep and superficial segments. The frequency of reflux in both superficial and deep segments increased with the clinical severity of disease. In 30.8% of subjects with CVI in the left leg, reflux was limited to the superficial system. Conclusions: The prevalence of CVI rises steeply with age. There is a strong correlation between venous symptoms and the presence and severity of CVI. CVI is associated in approximately one third of the subjects with incompetence limited to the superficial system and in these a good therapeutic outcome could be expected from surgery to the superficial veins. The severity of clinical features, including Basle CVI grade 1, correlates significantly with prevalence of valvular reflux in the deep and superficial systems. If leg ulcers are to be prevented by timely intervention, a better understanding of the natural history of the association between presenting features and disordered hemodynamics is required. (J Vasc Surg 2002;36:520-5.
G 112-29 (=NLTT 18149), a Very Wide Companion to GJ 282 AB with a Common Proper Motion, Common Parallax, Common Radial Velocity and Common Age
We have made a search for common proper motion (CPM) companions to the wide
binaries in the solar vicinity. We found that the binary GJ 282AB has a very
distant CPM companion (NLTT 18149) at a separation s=1.09 \arcdeg. Improved
spectral types and radial velocities are obtained, and ages determined for the
three components. The Hipparcos trigonometric parallaxes and the new radial
velocities and ages turn out to be very similar for the three stars, and
provide strong evidence that they form a physical system. At a projected
separation of 55733AU from GJ 282AB, NLTT 18149 ranks among the widest physical
companions known.Comment: 13 pages, 3 figures, submmited to Ap
Increased camptothecin toxicity induced in mammalian cells expressing Saccharomyces cerevisiae DNA topoisomerase I
The yeast Saccharomyces cerevisiae has been useful in establishing the phenotypic effects of specific mutations on the enzymatic activity and camptothecin sensitivity of yeast and human DNA topoisomerase I. To determine whether these phenotypes were faithfully reiterated in higher eukaryotic cells, wild-type and mutant yeast Top1 proteins were epitope-tagged at the amino terminus and transiently overexpressed in mammalian COS cells. Camptothecin preferentially induced apoptosis in cells expressing wild-type eScTop1p yet did not appreciably increase the cytotoxic response of cells expressing a catalytically inactive (eSctop1Y727F) or a catalytically active, camptothecin-resistant eSctop1vac mutant. Using an epitope-specific antibody, immobilized precipitates of eScTop1p were active in DNA relaxation assays, whereas immunoprecipitates of eScTop1Y727Fp were not. Thus, the enzyme retained catalytic activity while tethered to a support. Interestingly, the mutant eSctop1T722A, which mimics camptothecin-induced cytotoxicity in yeast through stabilization of the covalent enzyme-DNA intermediate, induced apoptosis in COS cells in the absence of camptothecin. This correlated with increased DNA cleavage in immunoprecipitates of eScTop1T722Ap, in the absence of the drug. The observation that the phenotypic consequences of expressing wild-type and mutant yeast enzymes were reiterated in mammalian cells suggests that the mechanisms underlying cellular responses to DNA topoisomerase I-mediated DNA damage are conserved between yeast and mammalian cells
Development of a porcine skeletal muscle cDNA microarray: analysis of differential transcript expression in phenotypically distinct muscles
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract Background Microarray profiling has the potential to illuminate the molecular processes that govern the phenotypic characteristics of porcine skeletal muscles, such as hypertrophy or atrophy, and the expression of specific fibre types. This information is not only important for understanding basic muscle biology but also provides underpinning knowledge for enhancing the efficiency of livestock production. Results We report on the de novo development of a composite skeletal muscle cDNA microarray, comprising 5500 clones from two developmentally distinct cDNA libraries (longissimus dorsi of a 50-day porcine foetus and the gastrocnemius of a 3-day-old pig). Clones selected for the microarray assembly were of low to moderate abundance, as indicated by colony hybridisation. We profiled the differential expression of genes between the psoas (red muscle) and the longissimus dorsi (white muscle), by co-hybridisation of Cy3 and Cy5 labelled cDNA derived from these two muscles. Results from seven microarray slides (replicates) correctly identified genes that were expected to be differentially expressed, as well as a number of novel candidate regulatory genes. Quantitative real-time RT-PCR on selected genes was used to confirm the results from the microarray. Conclusion We have developed a porcine skeletal muscle cDNA microarray and have identified a number of candidate genes that could be involved in muscle phenotype determination, including several members of the casein kinase 2 signalling pathway.Peer Reviewe
Recommended from our members
Bayesian retrieval of complete posterior PDFs of oceanic rain rate from microwave observations
A new Bayesian algorithm for retrieving surface rain rate from Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) over the ocean is presented, along with validations against estimates from the TRMM Precipitation Radar (PR). The Bayesian approach offers a rigorous basis for optimally combining multichannel observations with prior knowledge. While other rain-rate algorithms have been published that are based at least partly on Bayesian reasoning, this is believed to be the first self-contained algorithm that fully exploits Bayes’s theorem to yield not just a single rain rate, but rather a continuous posterior probability distribution of rain rate. To advance the understanding of theoretical benefits of the Bayesian approach, sensitivity analyses have been conducted based on two synthetic datasets for which the “true” conditional and prior distribution are known. Results demonstrate that even when the prior and conditional likelihoods are specified perfectly, biased retrievals may occur at high rain rates. This bias is not the result of a defect of the Bayesian formalism, but rather represents the expected outcome when the physical constraint imposed by the radiometric observations is weak owing to saturation effects. It is also suggested that both the choice of the estimators and the prior information are crucial to the retrieval. In addition, the performance of the Bayesian algorithm herein is found to be comparable to that of other benchmark algorithms in real-world applications, while having the additional advantage of providing a complete continuous posterior probability distribution of surface rain rate
Erratum to: How Can Psychological Science Inform Research About Genetic Counseling for Clinical Genomic Sequencing?
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147141/1/jgc40372.pd
How Can Psychological Science Inform Research About Genetic Counseling for Clinical Genomic Sequencing?
Next generation genomic sequencing technologies (including whole genome or whole exome sequencing) are being increasingly applied to clinical care. Yet, the breadth and complexity of sequencing information raise questions about how best to communicate and return sequencing information to patients and families in ways that facilitate comprehension and optimal health decisions. Obtaining answers to such questions will require multidisciplinary research. In this paper, we focus on how psychological science research can address questions related to clinical genomic sequencing by explaining emotional, cognitive, and behavioral processes in response to different types of genomic sequencing information (e.g., diagnostic results and incidental findings). We highlight examples of psychological science that can be applied to genetic counseling research to inform the following questions: (1) What factors influence patients’ and providers’ informational needs for developing an accurate understanding of what genomic sequencing results do and do not mean?; (2) How and by whom should genomic sequencing results be communicated to patients and their family members?; and (3) How do patients and their families respond to uncertainties related to genomic information?Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147034/1/jgc40193.pd
A Transient Sub-Eddington Black Hole X-ray Binary Candidate in the Dust Lanes of Centaurus A
We report the discovery of a bright X-ray transient, CXOU J132527.6-430023,
in the nearby early-type galaxy NGC 5128. The source was first detected over
the course of five Chandra observations in 2007, reaching an unabsorbed
outburst luminosity of 1-2*10^38 erg/s in the 0.5-7.0 keV band before returning
to quiescence. Such luminosities are possible for both stellar-mass black hole
and neutron star X-ray binary transients. Here, we attempt to characterize the
nature of the compact object. No counterpart has been detected in the optical
or radio sky, but the proximity of the source to the dust lanes allows for the
possibility of an obscured companion. The brightness of the source after a >100
fold increase in X-ray flux makes it either the first confirmed transient
non-ULX black hole system in outburst to be subject to detailed spectral
modeling outside the Local Group, or a bright (>10^38 erg/s) transient neutron
star X-ray binary, which are very rare. Such a large increase in flux would
appear to lend weight to the view that this is a black hole transient. X-ray
spectral fitting of an absorbed power law yielded unphysical photon indices,
while the parameters of the best-fit absorbed disc blackbody model are typical
of an accreting ~10 Msol black hole in the thermally dominant state.Comment: 8 pages, 6 figures, accepted for publication in Ap
- …