40 research outputs found

    Demographic analysis reveals gradual senescence in the flatworm Macrostomum lignano

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    Free-living flatworms ("Turbellaria") are appropriate model organisms to gain better insight into the role of stem cells in ageing and rejuvenation. Ageing research in flatworms is, however, still scarce. This is partly due to culture difficulties and the lack of a complete set of demographic data, including parameters such as median lifespan and age-specific mortality rate. In this paper, we report on the first flatworm survival analysis. We used the species Macrostomum lignano, which is an emerging model for studying the reciprocal influence between stem cells, ageing and rejuvenation. This species has a median lifespan of 205 ± 13 days (average ± standard deviation [SD]) and a 90th percentile lifespan of 373 ± 32 days. The maximum lifespan, however, is more than 745 days, and the average survival curve is characterised by a long tail because a small number of individuals lives twice as long as 90% of the population. Similar to earlier observations in a wide range of animals, in M. lignano the age-specific mortality rate increases exponentially, but levels off at the oldest ages. To compare the senescence of M. lignano with that of other ageing models, we determined the mortality rate doubling time, which is 0.20 ± 0.02 years. As a result, we can conclude that M. lignano shows gradual senescence at a rate similar to the vertebrate ageing models Rattus norvegicus and Mus musculus. We argue that M. lignano is a suitable model for ageing and rejuvenation research, and especially for the role of stem cells in these processes, due to its accessible stem cell system and regeneration capacity, and the possibility of combining stem cell studies with demographic analyses

    Emigration of European silver eel (Anguilla anguilla L.) from a polder system into the Schelde estuary

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    Connectivity between freshwater habitats and marine areas is heavily obstructed by migration barriers, leading to a high pressure on diadromous eel populations. Migration barriers attribute to the 98% decline of the European eel (Anguilla anguilla L.) population. A better understanding of eel behaviour regarding these barriers is needed for water managers to take proper mitigation actions. We tracked 50 eels by means of acoustic telemetry between July 2012 and January 2015 and analysed their migration behaviour in a Belgian polder area. On their way to the Schelde Estuary, eels face several migration barriers such as a pumping station, a weir and tidal barriers. The telemetry study did reveal significant delays and searching behaviour near those barriers. Depending on nothing but their accumulated fat, delays can have a serious impact on the fitness of the eel by wasting precious energy resources needed for a successful trans-Atlantic migration. In addition, delays and searching behaviour can also increase predation risk. The obtained knowledge can contribute to efficient management such as improved fish passage and guidance solutions

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Drosophila-parasitoid communities as model systems for host-Wolbachia interactions

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    International audienceWolbachia bacteria are cytoplasmic endosymbionts that infect a wide range of arthropod and nematode hosts. They are transmitted from mother to offspring via the eggs (vertical transmission) and enhance their transmission to the next generation by manipulating the reproductive system of their hosts. These manipulations occur in many forms, such as the induction of cytoplasmic incompatibility, feminization, male killing and parthenogenesis induction. Wolbachia is estimated to occur in up to 66% of all insect species, but the greatest diversity of reproductive manipulations is found in the order of the Hymenoptera. Studies of Wolbachia in Drosophila-parasitoid communities have allowed for important insights into different aspects of Wolbachia biology. The extensive knowledge available on Drosophila parasitoids provides a solid base on which to test new hypotheses on host-Wolbachia interactions. The large range of Wolbachia phenotypes present in Drosophila parasitoids, combined with the recent acquisition of the bacteria from their Drosophilid hosts, make them an ideal model system to study the evolution and dynamics of Wolbachia infections, both in the laboratory as in the field. In this chapter, we aim to review the current knowledge on the associations between Wolbachia and Drosophila parasitoids, and identify open questions and specify new research directions

    Clinical course and recommendations for patients after anterior cruciate ligament injury and subsequent reconstruction:A narrative review

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    Almost all athletes who have suffered an anterior cruciate ligament (ACL) injury expect a full return to sports at the same pre-injury level after ACL reconstruction (ACLR). Detailed patient information on the reasonable outcomes of the surgery may be essential to improve patient satisfaction.Pre-operative rehabilitation before ACLR should be considered as an addition to the standard of care to maximise functional outcomes after ACLR.We propose an optimised criterion-based rehabilitation programme within a biopsychosocial framework.No benchmark exists for evaluating return-to-sport (RTS) readiness after ACLR. Therefore, the authors propose a multi-factorial RTS test battery. A combination of both physical and psychological elements should be included in the RTS test battery.There is need for shared decision-making regarding RTS. Cite this article: EFORT Open Rev 2017;2:410-420. DOI: 10.1302/2058-5241.2.170011
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