263 research outputs found

    Tomosynthesis in pulmonary cystic fibrosis with comparison to radiography and computed tomography: a pictorial review

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    The purpose of this pictorial review is to illustrate chest imaging findings of cystic fibrosis (CF) using tomosynthesis (digital tomography), in comparison to radiography and computed tomography (CT). CF is a chronic systemic disease where imaging has long been used for monitoring chest status. CT exposes the patient to a substantially higher radiation dose than radiography, rendering it unsuitable for the often needed repeated examinations of these patients. Tomosynthesis has recently appeared as an interesting low dose alternative to CT, with an effective dose of approximately 0.08 mSv for children and 0.12 mSv for adults. Tomosynthesis is performed on the same X-ray system as radiography, adding only about 1 min to the normal examination time. Typical pulmonary changes in CF such as mucus plugging, bronchial wall thickening, and bronchiectases are shown in significantly better detail with tomosynthesis than with traditional radiography. In addition, the cost for a tomosynthesis examination is low compared to CT. To reduce the radiation burden of patients with CF it is important to consider low dose alternatives to CT, especially in the paediatric population. Tomosynthesis has a lower radiation dose than CT and gives a superior visualisation of pulmonary CF changes compared to radiography. It is important to further determine the role of tomosynthesis for monitoring disease progression in CF

    Open reduction and internal fixation compared to closed reduction and external fixation in distal radial fractures: A randomized study of 50 patients

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    Background and purpose In unstable distal radial fractures that are impossible to reduce or to maintain in reduced position, the treatment of choice is operation. The type of operation and the choice of implant, however, is a matter of discussion. Our aim was to investigate whether open reduction and internal fixation would produce a better result than traditional external fixation

    Impact of Center Experience on Patient Radiation Exposure During Transradial Coronary Angiography and Percutaneous Intervention: A Patient-Level, International, Collaborative, Multi-Center Analysis.

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    BACKGROUND: The adoption of the transradial (TR) approach over the traditional transfemoral (TF) approach has been hampered by concerns of increased radiation exposure-a subject of considerable debate within the field. We performed a patient-level, multi-center analysis to definitively address the impact of TR access on radiation exposure. METHODS AND RESULTS: Overall, 10 centers were included from 6 countries-Canada (2 centers), United Kingdom (2), Germany (2), Sweden (2), Hungary (1), and The Netherlands (1). We compared the radiation exposure of TR versus TF access using measured dose-area product (DAP). To account for local variations in equipment and exposure, standardized TR:TF DAP ratios were constructed per center with procedures separated by coronary angiography (CA) and percutaneous coronary intervention (PCI). Among 57 326 procedures, we demonstrated increased radiation exposure with the TR versus TF approach, particularly in the CA cohort across all centers (weighted-average ratios: CA, 1.15; PCI, 1.05). However, this was mitigated by increasing TR experience in the PCI cohort across all centers (r=-0.8; P=0.005). Over time, as a center transitioned to increasing TR experience (r=0.9; P=0.001), a concomitant decrease in radiation exposure occurred (r=-0.8; P=0.006). Ultimately, when a center's balance of TR to TF procedures approaches 50%, the resultant radiation exposure was equivalent. CONCLUSIONS: The TR approach is associated with a modest increase in patient radiation exposure. However, this increase is eliminated when the TR and TF approaches are used with equal frequency-a guiding principle for centers adopting the TR approach

    Weekly self-monitoring and treatment adjustment benefit patients with partly controlled and uncontrolled asthma: an analysis of the SMASHING study

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    <p>Abstract</p> <p>Background</p> <p>Internet-based self-management has shown to improve asthma control and asthma related quality of life, but the improvements were only marginally clinically relevant for the group as a whole. We hypothesized that self-management guided by weekly monitoring of asthma control tailors pharmacological therapy to individual needs and improves asthma control for patients with partly controlled or uncontrolled asthma.</p> <p>Methods</p> <p>In a 1-year randomised controlled trial involving 200 adults (18-50 years) with mild to moderate persistent asthma we evaluated the adherence with weekly monitoring and effect on asthma control and pharmacological treatment of a self-management algorithm based on the Asthma Control Questionnaire (ACQ). Participants were assigned either to the Internet group (n = 101) that monitored asthma control weekly with the ACQ on the Internet and adjusted treatment using a self-management algorithm supervised by an asthma nurse specialist or to the usual care group (UC) (n = 99). We analysed 3 subgroups: patients with well controlled (ACQ ≤ 0.75), partly controlled (0.75>ACQ ≤ 1.5) or uncontrolled (ACQ>1.5) asthma at baseline.</p> <p>Results</p> <p>Overall monitoring adherence was 67% (95% CI, 60% to 74%). Improvements in ACQ score after 12 months were -0.14 (p = 0.23), -0.52 (p < 0.001) and -0.82 (p < 0.001) in the Internet group compared to usual care for patients with well, partly and uncontrolled asthma at baseline, respectively. Daily inhaled corticosteroid dose significantly increased in the Internet group compared to usual care in the first 3 months in patients with uncontrolled asthma (+278 μg, p = 0.001), but not in patients with well or partly controlled asthma. After one year there were no differences in daily inhaled corticosteroid use or long-acting β<sub>2</sub>-agonists between the Internet group and usual care.</p> <p>Conclusions</p> <p>Weekly self-monitoring and subsequent treatment adjustment leads to improved asthma control in patients with partly and uncontrolled asthma at baseline and tailors asthma medication to individual patients' needs.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN79864465</p

    Comparison of the Commercial Color LCD and the Medical Monochrome LCD Using Randomized Object Test Patterns

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    Workstations and electronic display devices in a picture archiving and communication system (PACS) provide a convenient and efficient platform for medical diagnosis. The performance of display devices has to be verified to ensure that image quality is not degraded. In this study, we designed a set of randomized object test patterns (ROTPs) consisting of randomly located spheres with various image characteristics to evaluate the performance of a 2.5 mega-pixel (MP) commercial color LCD and a 3 MP diagnostic monochrome LCD in several aspects, including the contrast, resolution, point spread effect, and noise. The ROTPs were then merged into 120 abdominal CT images. Five radiologists were invited to review the CT images, and receiver operating characteristic (ROC) analysis was carried out using a five-point rating scale. In the high background patterns of ROTPs, the sensitivity performance was comparable between both monitors in terms of contrast and resolution, whereas, in the low background patterns, the performance of the commercial color LCD was significantly poorer than that of the diagnostic monochrome LCD in all aspects. The average area under the ROC curve (AUC) for reviewing abdominal CT images was 0.717±0.0200 and 0.740±0.0195 for the color monitor and the diagnostic monitor, respectively. The observation time (OT) was 145±27.6 min and 127±19.3 min, respectively. No significant differences appeared in AUC (p = 0.265) and OT (p = 0.07). The overall results indicate that ROTPs can be implemented as a quality control tool to evaluate the intrinsic characteristics of display devices. Although there is still a gap in technology between different types of LCDs, commercial color LCDs could replace diagnostic monochrome LCDs as a platform for reviewing abdominal CT images after monitor calibration

    A self-rating scale for patient-perceived side effects of inhaled corticosteroids

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    BACKGROUND: Patient-reported side effect questionnaires offer a simple method for the systematic measurement of drug-related side effects. In order to measure patients' inhaled corticosteroids (ICS) related side effect perceptions the 14-day retrospective Inhaled Corticosteroid Questionnaire (ICQ) was developed. In this research we aim to assess the construct validity and reliability of the ICQ and test its responsiveness to dose changes in adult asthma patients. METHODS: In a cross-sectional study, current inhaler users with asthma completed the ICQ (27 with non ICS inhaler; 61 BDP equivalent daily ICS low dose ≤400 μg; 62 mid dose 401–800 μg; and 105 with high dose >800 μg). We generated 3 construct validity hypotheses: 1) a hierarchical dose-response pattern for scoring of the individual items on the ICQ, and statistically significant differences in the scores of each of the 15 ICQ domains by ICS dose group 2) an association between ICS dose and ICQ scoring after adjusting for appropriate confounders in multiple regression; 3) greater convergence between local side effect domains than between systemic and local domains of the scale. Test-retest reliability was assessed on a randomly selected subgroup of patients (n = 73) who also completed the ICQ a second time after 7 days. In a separate longitudinal study, 61 patients with asthma completed the ICQ at baseline and after changing their daily ICS dose, at 2- and 6- months, in order to test the ICQ's responsiveness. RESULTS: All three construct validity hypotheses were well supported: 1) a statistically significant difference existed in scores for 14 domains, the high ICS dose group scoring highest; 2) ICS dose independently predicted ICQ scoring after adjusting for confounders; 3) greater convergence existed between local ICQ domains than between local and systemic domains. The ICQ had good reproducibility: test-retest intraclass correlation coefficients were ≥0.69 for all but the 'Facial Oedema' domain. In the longitudinal study, ICQ scores for 'Voice Problems' changed significantly at 2- and 6-months from baseline and other ICQ domains displayed trends in scoring change accordant with dose modulation at 6-months. CONCLUSION: The ICQ has good dose-related discriminative properties, is valid, reliable, and shows potential responsiveness to ICS dose change

    Lysine-91 of the tetraheme c-type cytochrome CymA is essential for quinone interaction and arsenate respiration in Shewanella sp. strain ANA-3

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    The tetraheme c-type cytochrome, CymA, is essential for arsenate respiratory reduction in Shewanella sp. ANA-3, a model arsenate reducer. CymA is predicted to mediate electron transfer from quinols to the arsenate respiratory reductase (ArrAB). Here, we present biochemical and physiological evidence that CymA interacts with menaquinol (MQH2) substrates. Fluorescence quench titration with the MQH2 analog, 2-n-heptyl-4-hydroxyquinoline-N-oxide (HOQNO), was used to demonstrate quinol binding of E. coli cytoplasmic membranes enriched with various forms of CymA. Wild-type CymA bound HOQNO with a Kd of 0.1–1 μM. It was also shown that the redox active MQH2 analog, 2,3-dimethoxy-1,4-naphthoquinone (DMNH2), could reduce CymA in cytoplasmic membrane preparations. Based on a CymA homology model made from the NrfH tetraheme cytochrome structure, it was predicted that Lys91 would be involved in CymA-quinol interactions. CymA with a K91Q substitution showed little interaction with HOQNO. In addition, DMNH2-dependent reduction of CymA-K91Q was diminished by 45% compared to wild-type CymA. A ΔcymA ANA-3 strain containing a plasmid copy of cymA-K91Q failed to grow with arsenate as an electron acceptor. These results suggest that Lys91 is physiologically important for arsenate respiration and support the hypothesis that CymA interacts with menaquinol resulting in the reduction of the cytochrome

    The effect of geographical scale of sampling on DNA barcoding.

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    Eight years after DNA barcoding was formally proposed on a large scale, CO1 sequences are rapidly accumulating from around the world. While studies to date have mostly targeted local or regional species assemblages, the recent launch of the global iBOL project (International Barcode of Life), highlights the need to understand the effects of geographical scale on Barcoding's goals. Sampling has been central in the debate on DNA Barcoding, but the effect of the geographical scale of sampling has not yet been thoroughly and explicitly tested with empirical data. Here, we present a CO1 data set of aquatic predaceous diving beetles of the tribe Agabini, sampled throughout Europe, and use it to investigate how the geographic scale of sampling affects 1) the estimated intraspecific variation of species, 2) the genetic distance to the most closely related heterospecific, 3) the ratio of intraspecific and interspecific variation, 4) the frequency of taxonomically recognized species found to be monophyletic, and 5) query identification performance based on 6 different species assignment methods. Intraspecific variation was significantly correlated with the geographical scale of sampling (R-square = 0.7), and more than half of the species with 10 or more sampled individuals (N = 29) showed higher intraspecific variation than 1% sequence divergence. In contrast, the distance to the closest heterospecific showed a significant decrease with increasing geographical scale of sampling. The average genetic distance dropped from > 7% for samples within 1 km, to 6000 km apart. Over a third of the species were not monophyletic, and the proportion increased through locally, nationally, regionally, and continentally restricted subsets of the data. The success of identifying queries decreased with increasing spatial scale of sampling; liberal methods declined from 100% to around 90%, whereas strict methods dropped to below 50% at continental scales. The proportion of query identifications considered uncertain (more than one species < 1% distance from query) escalated from zero at local, to 50% at continental scale. Finally, by resampling the most widely sampled species we show that even if samples are collected to maximize the geographical coverage, up to 70 individuals are required to sample 95% of intraspecific variation. The results show that the geographical scale of sampling has a critical impact on the global application of DNA barcoding. Scale-effects result from the relative importance of different processes determining the composition of regional species assemblages (dispersal and ecological assembly) and global clades (demography, speciation, and extinction). The incorporation of geographical information, where available, will be required to obtain identification rates at global scales equivalent to those in regional barcoding studies. Our result hence provides an impetus for both smarter barcoding tools and sprouting national barcoding initiatives-smaller geographical scales deliver higher accuracy
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