310 research outputs found

    Completeness and positive predictive value of registration of upper limb embolectomy in the Danish National Vascular Registry

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    Ljubica V Andersen1, Leif S Mortensen2, Jes S Lindholt3, Ole Faergeman4, Eskild W Henneberg3, Lars Frost51Department of Pharmacology, Odense University Hospital, Denmark; 2UNI-C, The Danish IT Centre for Education and Research, Aarhus, Denmark; 3Vascular Research Unit, Department of Vascular Surgery, Viborg Hospital, Denmark; 4Department of Cardiology and Internal Medicine, Aarhus University Hospital, Denmark; 5Department of Medicine, Silkeborg Hospital, DenmarkObjective: To evaluate completeness and positive predictive value of the Danish National Vascular Registry regarding registration of the surgical procedures: embolectomy of brachial, ulnar, or radial artery. Study design and settings: The study was based on first-time embolectomies in the brachial, ulnar, or radial artery performed in Denmark from January 1, 1990 to December 31, 2002. The data were primarily retrieved from the Danish National Vascular Registry and secondarily from the Danish National Registry of Patients. Medical records were retrieved using a standardized form.Results: In total, 1433 incident cases of first-time embolectomy were found in both registries. The positive predictive value of the registration was 97.5% (95% confidence interval [CI]; 96.4–98.4). The degree of completeness was 86.5% (95% CI; 84.3–88.5). For the registration period from 1990 till 1996 the degree of completeness was 78.2% (95% CI; 74.4–81.7), and from 1997 till 2002 it was 93.8% (95% CI; 91.6–95.7). Conclusion: The completeness and positive predictive value of registration of embolectomy in the upper limb in the Danish National Vascular Registry was 86.5% and 97.5%, respectively. This registry can be a valuable tool for epidemiological research and quality-monitoring. Keywords: positive predictive value, completeness, capture-recapture method, validity, embolectomy, registration

    New perspectives on evolutionary medicine: the relevance of microevolution for human health and disease

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    Evolutionary medicine (EM) is a growing field focusing on the evolutionary basis of human diseases and their changes through time. To date, the majority of EM studies have used pure theories of hominin macroevolution to explain the present-day state of human health. Here, we propose a different approach by addressing more empirical and health-oriented research concerning past, current and future microevolutionary changes of human structure, functions and pathologies. Studying generation-to-generation changes of human morphology that occurred in historical times, and still occur in present-day populations under the forces of evolution, helps to explain medical conditions and warns clinicians that their current practices may influence future humans. Also, analyzing historic tissue specimens such as mummies is crucial in order to address the molecular evolution of pathogens, of the human genome, and their coadaptations.Frank Jakobus Rühli and Maciej Henneber

    Two interpretations of human evolution: Essentialism and Darwinism

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    Despite intensive studies of a large number of fossils discovered during the 20th century there is no consensus as to the interpretation of the process of hominin evolution. Some authors see as many as six genera and some 17 species, while others argue for a single lineage from Plio/Pleistocene until today. Such diversity of interpretations of the same facts indicates lack of a uniform theoretical basis underlying studies of human evolution. Debates can be resolved using basic principles of scientific inquiry - parsimony and falsification of null hypotheses. Hypothesis testing is now possible with respect to the evolution of basic hominin characteristics such as brain size, body size and the size of the dentition that have sample sizes of a few hundred individual data points each. These characters display a continuous change with time. Analyses of variance do not falsify the null hypothesis of the existence of only one species at any time - variances around regression lines on time do not differ from the variance observed in the single species of Homo sapiens - distributions of residuals are normal. Thus, splitting of the hominin lineage into coeval species can only be based on descriptive characteristics that are liable to errors of subjective judgment.Maciej Henneber

    Perforated Meckel's diverticulum presenting with combined bowel and urinary obstruction and mimicking Crohn's disease: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Meckel's diverticulum is a common congenital anomaly of the gastrointestinal tract, but is an uncommon cause of serious complications in adults. Although cases of patients with hemorrhage, bowel obstruction or perforation associated with Meckel's diverticulum have been reported, there have been no prior reports of patients with combined urinary and bowel obstruction due to abscess formation.</p> <p>Case presentation</p> <p>We describe the case of a 21-year-old man with a history of recurrent papillary thyroid cancer, but no prior abdominal surgeries, who presented with a one-month history of rectal pain and new-onset obstipation with urinary retention. He reported night sweats and weight loss, and had a second-degree relative with known Crohn's disease. A digital rectal examination was notable and revealed marked tenderness with proximal induration. A computed tomography scan of the patient's abdomen revealed a large, complex, circumferential perirectal abscess compressing the rectal lumen and base of the urinary bladder, associated with terminal ileal thickening and an ileocecal fistula. A flexible sigmoidoscopy with an endorectal ultrasound scan displayed a complex abscess with extensive mucosal and surrounding inflammation. An exploratory laparotomy revealed a Meckel's diverticulum with a large perforation at its base, positioned near the ileocecal fistula and immediately superior to the perirectal abscess. The section of small bowel containing the Meckel's diverticulum, the terminal ileum, and the cecum, were all resected, and the abscess was debrided.</p> <p>Conclusions</p> <p>Pre-operative diagnosis of Meckel's diverticulum can be difficult. If the nature of the complication makes ultimate surgical management likely, an early laparoscopic or open exploration should be performed to prevent the morbidity and mortality associated with late complications.</p

    Frequency and type of adverse analytical findings in athletics: Differences among disciplines.

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    Athletics is a highly diverse sport that contains a set of disciplines grouped into jumps, throws, races of varying distances, and combined events. From a physiological standpoint, the physical capabilities linked to success are quite different among disciplines, with varying involvements of muscle strength, muscle power, and endurance. Thus, the use of banned substances in athletics might be dictated by physical dimensions of each discipline. Thus, the aim of this investigation was to analyse the number and distribution of adverse analytical findings per drug class in athletic disciplines. The data included in this investigation were gathered from the Anti-Doping Testing Figure Report made available by the World Anti-Doping Agency (from 2016 to 2018). Interestingly, there were no differences in the frequency of adverse findings (overall, 0.95%, range from 0.77 to 1.70%) among disciplines despite long distance runners having the highest number of samples analysed per year ( 9812 samples/year). Sprinters and throwers presented abnormally high proportions of adverse analytical findings within the group of anabolic agents (p < 0.01); middle- and long-distance runners presented atypically high proportions of findings related to peptide hormones and growth factors (p < 0.01); racewalkers presented atypically high proportions of banned diuretics and masking agents (p = 0.05). These results suggest that the proportion of athletes that are using banned substances is similar among the different disciplines of athletics. However, there are substantial differences in the class of drugs more commonly used in each discipline. This information can be used to effectively enhance anti-doping testing protocols in athletics.post-print1.911 K

    Anomalous ion diffusion within skeletal muscle transverse tubule networks

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    <p>Abstract</p> <p>Background</p> <p>Skeletal muscle fibres contain transverse tubular (t-tubule) networks that allow electrical signals to rapidly propagate into the fibre. These electrical signals are generated by the transport of ions across the t-tubule membranes and this can result in significant changes in ion concentrations within the t-tubules during muscle excitation. During periods of repeated high-frequency activation of skeletal muscle the t-tubule K<sup>+ </sup>concentration is believed to increase significantly and diffusive K<sup>+ </sup>transport from the t-tubules into the interstitial space provides a mechanism for alleviating muscle membrane depolarization. However, the tortuous nature of the highly branched space-filling t-tubule network impedes the diffusion of material through the network. The effective diffusion coefficient for ions in the t-tubules has been measured to be approximately five times lower than in free solution, which is significantly different from existing theoretical values of the effective diffusion coefficient that range from 2–3 times lower than in free solution. To resolve this discrepancy, in this paper we study the process of diffusion within electron microscope scanned sections of the skeletal muscle t-tubule network using mathematical modelling and computer simulation techniques. Our model includes t-tubule geometry, tautness, hydrodynamic and non-planar network factors.</p> <p>Results</p> <p>Using our model we found that the t-tubule network geometry reduced the K<sup>+ </sup>diffusion coefficient to 19–27% of its value in free solution, which is consistent with the experimentally observed value of 21% and is significantly smaller than existing theoretical values that range from 32–50%. We also found that diffusion in the t-tubules is anomalous for skeletal muscle fibres with a diameter of less than approximately 10–20 μm as a result of obstructed diffusion. We also observed that the [K<sup>+</sup>] within the interior of the t-tubule network during high-frequency activation is greater for fibres with a larger diameter. Smaller skeletal muscle fibres are therefore more resistant to membrane depolarization. Because the t-tubule network is anisotropic and inhomogeneous, we also found that the [K<sup>+</sup>] distribution generated within the network was irregular for fibres of small diameter.</p> <p>Conclusion</p> <p>Our model explains the measured effective diffusion coefficient for ions in skeletal muscle t-tubules.</p

    The Viborg vascular (VIVA) screening trial of 65-74 year old men in the central region of Denmark: study protocol

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    <p>Abstract</p> <p>Background</p> <p>Screening for abdominal aortic aneurysm (AAA) of men aged 65-74 years reduces the AAA-related mortality and is generally considered cost effective. Despite of this only a few national health care services have implemented permanent programs.</p> <p>Around 10% of men in this group have peripheral arterial disease (PAD) defined by an ankle brachial systolic blood pressure index (ABI) below 0.9 resulting in an increased mortality-rate of 25-30%. In addition well-documented health benefits may be achieved through primary prophylaxis by initiating systematic cholesterol-lowering, smoking cessation, low-dose acetylsalicylic acid (aspirins), exercise, a healthy diet and blood-pressure control altogether reducing the increased risks for cardiovascular disease by at least 20-25%.</p> <p>The benefits of combining screening for AAA and PAD seem evident; yet they remain to be established. The objective of this study is to assess the efficacy and the cost-effectiveness of a combined screening program for AAA, PAD and hypertension.</p> <p>Methods</p> <p>The Viborg Vascular (VIVA) screening trial is a randomized, clinically controlled study designed to evaluate the benefits of vascular screening and modern vascular prophylaxis in a population of 50,000 men aged 65-74 years. Enrolment started October 2008 and is expected to stop in October 2010. The primary outcome is all-cause mortality. The secondary outcomes are cardiovascular mortality, AAA-related mortality, hospital services related to cardiovascular conditions, prevalence of AAA, PAD and potentially undiagnosed hypertension, health-related quality of life and cost effectiveness. Data analysis by intention to treat.</p> <p>Results</p> <p>Major follow-up will be performed at 3, 5 and 10 years and final study result after 15 years.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00662480</p

    Gaining access to agency and structure in industrial marketing theory : a critical pluralist approach.

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    This article is concerned with gaining greater insight into the interplay between agency and structure in industrial marketing (IM) scholarship. The article’s intent is to embed Midgley’s notion of critical pluralism within this endeavour. The article commends the movement towards increased deployment of critical realism, but cautions against the dangers of creating further atomism in marketing theory by generating another paradigm of thought with strongly defended boundaries, impervious to outside influence. The article advances a case for critical pluralism within IM scholarship and offers a three-dimensional (theoretical, methodological and methodical) framework to aid this. The discussion demonstrates how critical pluralism can be deployed to gain insights into agency and structure using a number of ‘integrative’ theoretical perspectives
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