74 research outputs found

    Hepatic artery aneurysm repair: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hepatic artery aneurysms remain a clinically significant entity. Their incidence continues to rise slowly and mortality from spontaneous rupture is high. Repair is recommended in those aneurysms greater than 2 cm in diameter. It is not surprising that vascular comorbidities, such as ischaemic heart disease, are common in surgical patients, particularly those with arterial aneurysms such as these. The decision of when to operate on patients who require urgent surgery despite having recently suffered an acute coronary syndrome remains somewhat of a grey and controversial area. We discuss the role of delayed surgery and postoperative followup of this vascular problem.</p> <p>Case presentation</p> <p>A 58-year-old man was admitted with a 5.5 cm hepatic artery aneurysm. The aneurysm was asymptomatic and was an incidental finding as a result of an abdominal computed tomography scan to investigate an episode of haemoptysis (Figure <figr fid="F1">1</figr>). Three weeks prior to admission, the patient had suffered a large inferior myocardial infarction and was treated by thrombolysis and primary coronary angioplasty. Angiographic assessment revealed a large aneurysm of the common hepatic artery involving the origins of the hepatic, gastroduodenal, left and right gastric arteries and the splenic artery (Figures <figr fid="F2">2</figr> and <figr fid="F3">3</figr>). Endovascular treatment was not considered feasible and immediate surgery was too high-risk in the early post-infarction period. Therefore, surgery was delayed for 3 months when aneurysm repair with reconstruction of the hepatic artery was successfully performed. Graft patency was confirmed with the aid of an abdominal arterial duplex. Plasma levels of conventional liver function enzymes and of alpha-glutathione-<it>S</it>-transferase were within normal limits. This was used to assess the extent of any hepatocellular damage perioperatively. The patient made a good recovery and was well at his routine outpatient check-ups.</p> <p>Conclusion</p> <p>There is no significant difference in cardiac risk in patients who have undergone vascular surgery within 6 months of a myocardial infarction compared with those who have had the operation in the 6 to12 month time frame. Use of alpha-glutathione-<it>S</it>-transferase gives an indication of the immediate state of hepatic function and should be used in addition to traditional liver function tests to monitor hepatic function postoperatively.</p

    Multiple Parton Interactions in Z+jets production at the LHC. A comparison of factorized and non--factorized double parton distribution functions

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    We examine the contribution of Multiple Parton Interactions to Z+n-jets production at the LHC, n=2,3,4, where the Z boson is assumed to decay leptonically. We compare the results obtained with the correlated GS09 double parton distribution function with those obtained with two instances of fully factorized single parton distribution functions: MSTW2008LO and CTEQ6LO. It appears quite feasible to measure the MPI contribution to Z+2/3/4 jets already in the first phase of the LHC with a total luminosity of one inverse femtobarn at 7 TeV. If as expected the trigger threshold for single photons is around 80 GeV, Z+2-jets production may well turn out to be more easily observable than the gamma+3-jets channel. The MPI cross section is dominated by relatively soft events with two jets balancing in transverse momentum.Comment: 15 pages, 3 plot

    Discovery of mating in the major African livestock pathogen Trypanosoma congolense

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    The protozoan parasite, Trypanosoma congolense, is one of the most economically important pathogens of livestock in Africa and, through its impact on cattle health and productivity, has a significant effect on human health and well being. Despite the importance of this parasite our knowledge of some of the fundamental biological processes is limited. For example, it is unknown whether mating takes place. In this paper we have taken a population genetics based approach to address this question. The availability of genome sequence of the parasite allowed us to identify polymorphic microsatellite markers, which were used to genotype T. congolense isolates from livestock in a discrete geographical area of The Gambia. The data showed a high level of diversity with a large number of distinct genotypes, but a deficit in heterozygotes. Further analysis identified cryptic genetic subdivision into four sub-populations. In one of these, parasite genotypic diversity could only be explained by the occurrence of frequent mating in T. congolense. These data are completely inconsistent with previous suggestions that the parasite expands asexually in the absence of mating. The discovery of mating in this species of trypanosome has significant consequences for the spread of critical traits, such as drug resistance, as well as for fundamental aspects of the biology and epidemiology of this neglected but economically important pathogen

    Comparative Phylogeography of a Coevolved Community: Concerted Population Expansions in Joshua Trees and Four Yucca Moths

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    Comparative phylogeographic studies have had mixed success in identifying common phylogeographic patterns among co-distributed organisms. Whereas some have found broadly similar patterns across a diverse array of taxa, others have found that the histories of different species are more idiosyncratic than congruent. The variation in the results of comparative phylogeographic studies could indicate that the extent to which sympatrically-distributed organisms share common biogeographic histories varies depending on the strength and specificity of ecological interactions between them. To test this hypothesis, we examined demographic and phylogeographic patterns in a highly specialized, coevolved community – Joshua trees (Yucca brevifolia) and their associated yucca moths. This tightly-integrated, mutually interdependent community is known to have experienced significant range changes at the end of the last glacial period, so there is a strong a priori expectation that these organisms will show common signatures of demographic and distributional changes over time. Using a database of >5000 GPS records for Joshua trees, and multi-locus DNA sequence data from the Joshua tree and four species of yucca moth, we combined paleaodistribution modeling with coalescent-based analyses of demographic and phylgeographic history. We extensively evaluated the power of our methods to infer past population size and distributional changes by evaluating the effect of different inference procedures on our results, comparing our palaeodistribution models to Pleistocene-aged packrat midden records, and simulating DNA sequence data under a variety of alternative demographic histories. Together the results indicate that these organisms have shared a common history of population expansion, and that these expansions were broadly coincident in time. However, contrary to our expectations, none of our analyses indicated significant range or population size reductions at the end of the last glacial period, and the inferred demographic changes substantially predate Holocene climate changes

    The genetic epidemiology of joint shape and the development of osteoarthritis

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    Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed

    Song plasticity over time and vocal learning in clay-colored thrushes

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    Songbirds have been traditionally classified into close-ended or open-ended learning species according to the length of the sensitive period during which birds are able to memorize new vocalizations. Closed-ended learners are generally not capable of changing their song after the first year of life, while open-ended learners show song plasticity as adults. A few Turdus species have been sug- gested to be open-ended learners, but no long-term study has been conducted to investigate their song plasticity over time. We analyzed the songs of clay-colored thrushes, T. grayi, over four successive breeding seasons to assess song plasticity in their syllable repertoires within and between breeding seasons. A total of 16,262 syllables were classi- fied through visual inspection of spectrograms and multi- dimensional scaling analysis based on spectrogram correlations. On average, 563 ± 153 (SD) syllables per male per breeding season were analyzed. Male repertoire size was 9–20 syllable types. Males were capable of modifying their syllable repertoire between the initial and final periods of the breeding season. Song plasticity within breeding seasons may be associated with imitation between neighboring males, suggesting song learning in males that were C2 years old. This short-term plasticity is not enough, however, to explain the high proportion of change (mean = 65 % syllable types) in repertoire composition between breeding seasons in adult males. Song plasticity resulting from annual changes in repertoire composition could be explained by open-ended learning, but another mechanism, extended memory and re-expression, could also explain long-term plasticity. Experimental studies controlling the acoustic environment are needed to determine which mechanism is responsible for such a high level of song plasticity.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

    The UK10K project identifies rare variants in health and disease

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    M. Kivimäki työryhmäjäsen.The contribution of rare and low-frequency variants to human traits is largely unexplored. Here we describe insights from sequencing whole genomes (low read depth, 7x) or exomes (high read depth, 80x) of nearly 10,000 individuals from population-based and disease collections. In extensively phenotyped cohorts we characterize over 24 million novel sequence variants, generate a highly accurate imputation reference panel and identify novel alleles associated with levels of triglycerides (APOB), adiponectin (ADIPOQ) and low-density lipoprotein cholesterol (LDLR and RGAG1) from single-marker and rare variant aggregation tests. We describe population structure and functional annotation of rare and low-frequency variants, use the data to estimate the benefits of sequencing for association studies, and summarize lessons from disease-specific collections. Finally, we make available an extensive resource, including individual-level genetic and phenotypic data and web-based tools to facilitate the exploration of association results.Peer reviewe

    Ecological patterns of blood-feeding by kissing-bugs (Hemiptera: Reduviidae: Triatominae)

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    Interactions in the Root Environment: An Integrated Approach (Editors)

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