52 research outputs found
Testing dose-dependent effects of stacked Bt maize pollen on in vitro-reared honey bee larvae
International audienceAbstractIn agricultural landscapes all over the world, honey bees are exposed to genetically modified (GM) pollen. Stacked Bt-maize varieties combine multiple Bt proteins against different insect taxa with herbicide resistance. To test for potential effects on non-target organisms, we conducted an in vitro larvae-rearing experiment where we fed increasing amounts of stacked Bt pollen to honey bee larvae. Bt pollen was equally well digested as two control maize varieties. No dose-dependent effects of Bt maize were detected in terms of survival and developmental delay. However, for prepupal weight we did find a dose-dependent response, suggesting a pleiotropic effect. Comparing this finding with the literature we conclude that the found effect is not likely to occur in a field situation. We could however show that dose-dependent effects are detectable. Our results underline the importance of testing dose-depending effects of GM plant material in an environmental risk assessment (ERA)
Efficacy of Bifidobacterium animalis subsp. lactis (BB-12), B. infantis and Lactobacillus acidophilus (La-5) probiotics to prevent gut dysbiosis in preterm infants of 28+0â32+6 weeks of gestation: a randomised, placebocontrolled, double-blind, multicentre trial: the PRIMAL Clinical Study Protocol
Introduction The healthy âeubiosisâ microbiome in infancy is regarded as the microbiome derived from term, vaginally delivered, antibiotic free, breastfed infants at 4â6 months. Dysbiosis is regarded as a deviation from a healthy state with reduced microbial diversity and deficient capacity to control drug-resistant organisms. Preterm infants are highly sensitive to early gut dysbiosis. Latter has been associated with sepsis and necrotising enterocolitis, but may also contribute to long-term health problems. Probiotics hold promise to reduce the risk for adverse short-term outcomes but the evidence from clinical trials remains inconclusive and none has directly assessed the effects of probiotics on the microbiome at high resolution.
Methods and analysis A randomised, double blind, placebo-controlled study has been designed to assess the safety and efficacy of the probiotic mix of Bifidobacterium animalis subsp. lactis, B. infantis and Lactobacillus acidophilus in the prevention of gut dysbiosis in preterm infants between 28+0âand 32+6 weeks of gestation. The study is conducted in 18 German neonatal intensive care units. Between April 2018 and March 2020, 654 preterm infants of 28+0â32+6 weeks of gestation will be randomised in the first 48âhours of life to 28 days of once daily treatment with either probiotics or placebo. The efficacy endpoint is the prevention of gut dysbiosis at day 30 of life. A compound definition of gut dysbosis is used: (1) colonisation with multidrug-resistant organisms or gram-negative bacteria with high epidemic potential or (2) a significant deviation of the gut microbiota composition as compared with healthy term infants. Dysbiosis is determined by (1) conventional microbiological culture and (2) phylogenetic microbiome analysis by high-throughput 16S rRNA and metagenome sequencing. Persistence of dysbiosis will be assessed at 12-month follow-up visits. Side effects and adverse events related to the intervention will be recorded. Key secondary endpoint(s) are putative consequences of dysbiosis. A subgroup of infants will be thoroughly phenotyped for immune parameters using chipcytometry.
Ethics and dissemination Ethics approval was obtained in all participating sites. Results of the trial will be published in peer-review journals, at scientific meetings, on the website (www.primal-study.de) and via social media of parent organisations. Trial registration number DRKS00013197; Pre-results
Attitudes towards complementary and alternative medicine in chronic pain syndromes: a questionnaire-based comparison between primary headache and low back pain
<p>Abstract</p> <p>Background</p> <p>Complementary and Alternative Medicine (CAM) is widely used and popular among patients with primary headache or low back pain (LBP). Aim of the study was to analyze attitudes of headache and LBP patients towards the use of CAM.</p> <p>Methods</p> <p>Two questionnaire-based surveys were applied comparing 432 primary headache and 194 LBP patients.</p> <p>Results</p> <p>In total, 84.75% of all patients reported use of CAM; with significantly more LBP patients. The most frequently-used CAM therapies in headache were acupuncture (71.4%), massages (56.4%), and thermotherapy (29.2%), in LBP thermotherapy (77.4%), massages (62.7%), and acupuncture (51.4%). The most frequent attitudes towards CAM use in headache vs. LBP: "leave nothing undone" (62.5% vs. 52.1%; p = 0.006), "take action against the disease" (56.8% vs. 43.2%; p = 0.006). Nearly all patients with previous experience with CAM currently use CAM in both conditions (93.6% in headache; 100% in LBP). However, the majority of the patients had no previous experience.</p> <p>Conclusion</p> <p>Understanding motivations for CAM treatment is important, because attitudes derive from wishes for non-pharmacological treatment, to be more involved in treatment and avoid side effects. Despite higher age and more permanent pain in LBP, both groups show high use of CAM with only little specific difference in preferred methods and attitudes towards CAM use. This may reflect deficits and unfulfilled goals in conventional treatment. Maybe CAM can decrease the gap between patients' expectations about pain therapy and treatment reality, considering that both conditions are often chronic diseases, causing high burdens for daily life.</p
The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry
Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes
Evolution of intraspecific social parasitism in honeybee workers (Apis mellifera capensis Esch)
Das Ziel meiner Arbeit war die Analyse eines durch legende Arbeiterinnen der Kaphonigbiene Apis mellifera capensis verursachten Sozialparasitismus. Bislang war intraspezifischer Sozialparasitismus durch legende Arbeiterinnen entweder wenig beachtet oder, wie im Falle von A. m. capensis, als ein durch Imkerei hervorgerufenes Artefakt betrachtet worden. Im Gegensatz hierzu konnte ich im ersten Teil meiner Arbeit zeigen, dass dieser Sozialparasitismus tatsĂ€chlich nicht nur ein durch menschliche EinflĂŒsse hervorgerufenes PhĂ€nomen ist, sondern einen natĂŒrlichen Teil des Verhaltensrepertoires der Honigbiene darstellt. Im zweiten Teil der Arbeit habe ich unter Zuhilfenahme von genetischen und gaschromatographischen Techniken die komplexen proximaten Mechanismen untersucht, mit denen A. m. capensis Arbeiterinnen den sozialparasitischen Status innerhalb der A. m. scutellata Wirtskolonie etablieren. Hierdurch ergĂ€nzt meine Arbeit die eher deskriptiven Veröffentlichungen zum intraspezifischen Sozialparasitismus bei Hummeln und Zwerghonigbienen- Arbeiterinnen substantiell. Weiterhin können die Ergebnisse dieser Arbeit helfen, den Sozialparasitismus von legenden A. m. capensis Arbeiterinnen, der in SĂŒdafrika zu erheblichen Völkerverlusten fĂŒhrt, besser zu verstehen und zu behandeln.The goal of my thesis was to analyse the social parasitism carried out by laying Cape honeybee, Apis mellifera capensis, workers. Intraspecific social parasitism by laying workers was widely unattended or in the case of the honeybee disposed as an artefact of beekeeping. In contrast to that, I have shown in the first part of my thesis that socially parasitic behaviour of workers is not only a man made phenomenon but is indeed an inherent part of the biology of the Western honeybee. In the second part of my thesis, I have analysed in detail the proximate mechanisms by which A. m. capensis workers establish themselves as social parasites within A. m. scutellata colonies. This thesis, thus, replenishes substantially the more descriptive papers about intraspecific social parasitism by laying workers in bumblebees and dwarf honeybees. Furthermore, the results may help to understand and manage the socially parasitic A. m. capensis workers which are a severe pest for apiculture in Northern South Africa.von Stephan HĂ€rte
Removal of small hive beetle (Aethina tumida) eggs and larvae by African honeybee colonies (Apis mellifera scutellata)
The removal of small hive beetle [SHB] eggs and larvae was studied in seven Apis mellifera scutellata colonies. Because female beetles can protect their eggs by oviposition in small cracks we introduced unprotected eggs and protected eggs into these colonies. Whereas all unprotected eggs were removed within 24 hours, % of the protected eggs remained, showing that SHB eggs are likely to hatch in infested colonies. However, all larvae introduced into the same seven colonies were rejected within 24 hours. Workers responded quickly to the presence of SHB offspring in the colonies because % of the unprotected eggs and % of the larvae were removed within the first hour after introduction. The removal of SHB eggs and larvae was not correlated with colony phenotypes (size, amount of open and sealed brood, pollen and honey stores). Our data show that African colonies remove both SHB unprotected eggs and larvae within short periods of time. Therefore, we conclude that this removal behavior plays an important role for the apparent resistance of African honeybees towards SHB infestations
A new device for monitoring individual activity rhythms of honey bees reveals critical effects of the social environment on behavior
Chronobiological studies of individual activity rhythms in social insects can be constrained by the artificial isolation of individuals from their social context. We present a new experimental set-up that simultaneously measures the temperature rhythm in a queen-less but brood raising mini colony and the walking activity rhythms of singly kept honey bees that have indirect social contact with it. Our approach enables monitoring of individual bees in the social context of a mini colony under controlled laboratory conditions. In a pilot experiment, we show that social contact with the mini colony improves the survival of monitored young individuals and affects locomotor activity patterns of young and old bees. When exposed to conflicting Zeitgebers consisting of a light-dark (LD) cycle that is phase-delayed with respect to the mini colony rhythm, rhythms of young and old bees are socially synchronized with the mini colony rhythm, whereas isolated bees synchronize to the LD cycle. We conclude that the social environment is a stronger Zeitgeber than the LD cycle and that our new experimental set-up is well suited for studying the mechanisms of social entrainment in honey bees
Ecology: Honey Bee Foraging in Human-Modified Landscapes
SummaryComprehensive information on the spatial resource use of honey bees is rare, but highly relevant to assess the consequences of habitat loss and fragmentation, agricultural intensification or extensification on colony fitness, pesticide exposure risks and pollination functions
The pigment-dispersing factor neuronal network systematically grows in developing honey bees
The neuropeptide pigment-dispersing factor (PDF) plays a prominent role in the circadian clock of many insects including honey bees. In the honey bee brain, PDF is expressed in about 15 clock neurons per hemisphere that lie between the central brain and the optic lobes. As in other insects, the bee PDF neurons form wide arborizations in the brain, but certain differences are evident. For example, they arborize only sparsely in the accessory medulla (AME), which serves as important communication center of the circadian clock in cockroaches and flies. Furthermore, all bee PDF neurons cluster together, which makes it impossible to distinguish individual projections. Here, we investigated the developing bee PDF network and found that the first three PDF neurons arise in the third larval instar and form a dense network of varicose fibers at the base of the developing medulla that strongly resembles the AME of hemimetabolous insects. In addition, they send faint fibers toward the lateral superior protocerebrum. In last larval instar, PDF cells with larger somata appear and send fibers toward the distal medulla and the medial protocerebrum. In the dorsal part of the medulla serpentine layer, a small PDF knot evolves from which PDF fibers extend ventrally. This knot disappears during metamorphosis and the varicose arborizations in the putative AME become fainter. Instead, a new strongly stained PDF fiber hub appears in front of the lobula. Simultaneously, the number of PDF neurons increases and the PDF neuronal network in the brain gets continuously more complex
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