17 research outputs found
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
Stimulation of the Sphenopalatine Ganglion Induces Reperfusion and Blood-Brain Barrier Protection in the Photothrombotic Stroke Model
The treatment of stroke remains a challenge. Animal studies showing that electrical stimulation of the sphenopalatine ganglion (SPG) exerts beneficial effects in the treatment of stroke have led to the initiation of clinical studies. However, the detailed effects of SPG stimulation on the injured brain are not known.The effect of acute SPG stimulation was studied by direct vascular imaging, fluorescent angiography and laser Doppler flowmetry in the sensory motor cortex of the anaesthetized rat. Focal cerebral ischemia was induced by the rose bengal (RB) photothrombosis method. In chronic experiments, SPG stimulation, starting 15 min or 24 h after photothrombosis, was given for 3 h per day on four consecutive days. Structural damage was assessed using histological and immunohistochemical methods. Cortical functions were assessed by quantitative analysis of epidural electro-corticographic (ECoG) activity continuously recorded in behaving animals.Stimulation induced intensity- and duration-dependent vasodilation and increased cerebral blood flow in both healthy and photothrombotic brains. In SPG-stimulated rats both blood brain-barrier (BBB) opening, pathological brain activity and lesion volume were attenuated compared to untreated stroke animals, with no apparent difference in the glial response surrounding the necrotic lesion.SPG-stimulation in rats induces vasodilation of cortical arterioles, partial reperfusion of the ischemic lesion, and normalization of brain functions with reduced BBB dysfunction and stroke volume. These findings support the potential therapeutic effect of SPG stimulation in focal cerebral ischemia even when applied 24 h after stroke onset and thus may extend the therapeutic window of currently administered stroke medications
The Quality of Registration of Clinical Trials
BACKGROUND: Lack of transparency in clinical trial conduct, publication bias and selective reporting bias are still important problems in medical research. Through clinical trials registration, it should be possible to take steps towards resolving some of these problems. However, previous evaluations of registered records of clinical trials have shown that registered information is often incomplete and non-meaningful. If these studies are accurate, this negates the possible benefits of registration of clinical trials. METHODS AND FINDINGS: A 5% sample of records of clinical trials that were registered between 17 June 2008 and 17 June 2009 was taken from the International Clinical Trials Registry Platform (ICTRP) database and assessed for the presence of contact information, the presence of intervention specifics in drug trials and the quality of primary and secondary outcome reporting. 731 records were included. More than half of the records were registered after recruitment of the first participant. The name of a contact person was available in 94.4% of records from non-industry funded trials and 53.7% of records from industry funded trials. Either an email address or a phone number was present in 76.5% of non-industry funded trial records and in 56.5% of industry funded trial records. Although a drug name or company serial number was almost always provided, other drug intervention specifics were often omitted from registration. Of 3643 reported outcomes, 34.9% were specific measures with a meaningful time frame. CONCLUSIONS: Clinical trials registration has the potential to contribute substantially to improving clinical trial transparency and reducing publication bias and selective reporting. These potential benefits are currently undermined by deficiencies in the provision of information in key areas of registered records
A new minimum fluorescence parameter, as generated using pulse frequency modulation, compared with pulse amplitude modulation: F α versus F o
Migraine patients should be cautiously followed for risk factors leading to cardiovascular disease
Migraine and ischemic strokes are two of the most prevalent diseases worldwide. Besides having a coincident symptomatology, for long researchers have been searching for a possible causal relation between these diseases. Current evidence based on data suggest that patients with aura migraine could have a doubled risk of developing an ischemic stroke, when compared to the rest of the population. At the same time, migraine sufferers apparently have higher incidences of risk factors for cardiovascular events. The aim of this review was not only to dissect some of the more compelling evidence based on data regarding this association, but also to discuss the possible clinical and therapeutic implications
Role of Nitric Oxide Synthase Inhibition in Leukocyte-Endothelium Interaction in the Rat Pial Microvasculature
Combined mass mapping and biochemical characterization of grape beta-glycosidase-enriched extract
International audienceA beta-glucosidase enzyme activity was enriched from skins of ripe grape berry by cell wall fractionation, hydrophobic interaction and cation-exchange chromatographies. This enriched enzyme extract contained several beta-glycosidase activities hydrolyzing a wide range of synthetic and natural monoglycosides and diglycosides, as well as a beta-fructosidase activity. The enzyme extract was further characterized by two-dimensional gel electrophoresis coupled to peptide mass fingerprinting of eight spots using MALDI-TOF mass spectrometry. No beta-glucosidase but a beta-fructosidase associated to the relevant spot at 66 kDa/pI 5.1 was identified. Taken together all results issued from the biochemical characterization, the substrate specificity and the mass spectrometry-based identification of this enriched enzyme extract, we propose that this protein could be a specific beta-fructosidase isoform associated with a broad spectrum of beta-glycosidase activities in grape berry skin and involved in cell wall modifications which occur during the ripening-induced thickness of the grap
