788 research outputs found

    Growth differentiation factor 15 increases in both cerebrospinal fluid and serum during pregnancy

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    AIM:Growth differentiation factor 15 (GDF15) increases in serum during pregnancy to levels not seen in any other physiological state and is suggested to be involved in pregnancy-induced nausea, weight regulation and glucose metabolism. The main action of GDF15 is regulated through a receptor of the brainstem, i.e., through exposure of GDF15 in both blood and cerebrospinal fluid (CSF). The aim of the current study was to measure GDF15 in both CSF and serum during pregnancy, and to compare it longitudinally to non-pregnant levels. METHODS: Women were sampled at elective caesarean section (n = 45, BMI = 28.1±5.0) and were followed up 5 years after pregnancy (n = 25). GDF15, insulin and leptin were measured in CSF and serum. Additional measurements included plasma glucose, and serum adiponectin and Hs-CRP. RESULTS: GDF15 levels were higher during pregnancy compared with follow-up in both CSF (385±128 vs. 115±32 ng/l, P<0.001) and serum (73789±29198 vs. 404±102 ng/l, P<0.001). CSF levels correlated with serum levels during pregnancy (P<0.001), but not in the non-pregnant state (P = 0.98). Both CSF and serum GDF15 were highest in women carrying a female fetus (P<0.001). Serum GDF15 correlated with the homeostatic model assessment for beta-cell function and placental weight, and CSF GDF15 correlated inversely with CSF insulin levels. CONCLUSION: This, the first study to measure CSF GDF15 during pregnancy, demonstrated increased GDF15 levels in both serum and CSF during pregnancy. The results suggest that effects of GDF15 during pregnancy can be mediated by increases in both CSF and serum levels

    A Systematic Review of Magnesium Sulfate for Perinatal Neuroprotection: What Have We Learnt From the Past Decade?

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    There is an important unmet need to improve long term outcomes of encephalopathy for preterm and term infants. Meta-analyses of large controlled trials suggest that maternal treatment with magnesium sulfate (MgSO4) is associated with a reduced risk of cerebral palsy and gross motor dysfunction after premature birth. However, to date, follow up to school age has found an apparent lack of long-term clinical benefit. Because of this inconsistency, it remains controversial whether MgSO4 offers sustained neuroprotection. We systematically reviewed preclinical and clinical studies reported from January 1 2010, to January 31 2020 to evaluate the most recent advances and knowledge gaps relating to the efficacy of MgSO4 for the treatment of perinatal brain injury. The outcomes of MgSO4 in preterm and term-equivalent animal models of perinatal encephalopathy were highly inconsistent between studies. None of the perinatal rodent studies that suggested benefit directly controlled body or brain temperature. The majority of the studies did not control for sex, study long term histological and functional outcomes or use pragmatic treatment regimens and many did not report controlling for potential study bias. Finally, most of the recent preterm or term human studies that tested the potential of MgSO4 for perinatal neuroprotection were relatively underpowered, but nevertheless, suggest that any improvements in neurodevelopment were at best modest or absent. On balance, these data suggest that further rigorous testing in translational preclinical models of perinatal encephalopathy is essential to ensure safety and best regimens for optimal preterm neuroprotection, and before further clinical trials of MgSO4 for perinatal encephalopathy at term are undertaken

    Lipopolysaccharide-induced alteration of mitochondrial morphology induces a metabolic shift in microglia modulating the inflammatory response in vitro and in vivo

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    Accumulating evidence suggests that changes in the metabolic signature of microglia underlie their response to inflammation. We sought to increase our knowledge of how pro‐inflammatory stimuli induce metabolic changes. Primary microglia exposed to lipopolysaccharide (LPS)‐expressed excessive fission leading to more fragmented mitochondria than tubular mitochondria. LPS‐mediated Toll‐like receptor 4 (TLR4) activation also resulted in metabolic reprogramming from oxidative phosphorylation to glycolysis. Blockade of mitochondrial fission by Mdivi‐1, a putative mitochondrial division inhibitor led to the reversal of the metabolic shift. Mdivi‐1 treatment also normalized the changes caused by LPS exposure, namely an increase in mitochondrial reactive oxygen species production and mitochondrial membrane potential as well as accumulation of key metabolic intermediate of TCA cycle succinate. Moreover, Mdivi‐1 treatment substantially reduced LPS induced cytokine and chemokine production. Finally, we showed that Mdivi‐1 treatment attenuated expression of genes related to cytotoxic, repair, and immunomodulatory microglia phenotypes in an in vivo neuroinflammation paradigm. Collectively, our data show that the activation of microglia to a classically pro‐inflammatory state is associated with a switch to glycolysis that is mediated by mitochondrial fission, a process which may be a pharmacological target for immunomodulation

    Recent Observations of Betelgeuse and New Instrumentation at the ISI

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    The Infrared Spatial Interferometer (ISI) has been conducting mid-infrared observations of late-type stars for about 18 years. A long-term set of diameter measurements of Betelgeuse at 11.15 μm shows pronounced changes in the stellar size over time. These changes may arise from variations in the opacity of the environment immediately surrounding the star. New instrumentation is being developed to identify the composition and kinematics of the circumstellar environment of Betelgeuse, and of other late-type stars. A digital spectrometer-correlator is being built and tested that will enable visibility measurements on and off individual molecular spectral lines. Results from testing the spectrometer system are presented

    Experimental investigation of planar ion traps

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    Chiaverini et al. [Quant. Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of 0.44 micron diameter charged particles in a vacuum of 15 Pa (0.1 torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional DC biased electrode above the trap which increases the trap depth dramatically, and a novel planar ion trap geometry that generates a two dimensional lattice of point Paul traps.Comment: 11 pages, 20 figure

    A simple genetic basis of adaptation to a novel thermal environment results in complex metabolic rewiring in Drosophila

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    BACKGROUND:Population genetic theory predicts that rapid adaptation is largely driven by complex traits encoded by many loci of small effect. Because large-effect loci are quickly fixed in natural populations, they should not contribute much to rapid adaptation. RESULTS:To investigate the genetic architecture of thermal adaptation - a highly complex trait - we performed experimental evolution on a natural Drosophila simulans population. Transcriptome and respiration measurements reveal extensive metabolic rewiring after only approximately 60 generations in a hot environment. Analysis of genome-wide polymorphisms identifies two interacting selection targets, Sestrin and SNF4Aγ, pointing to AMPK, a central metabolic switch, as a key factor for thermal adaptation. CONCLUSIONS:Our results demonstrate that large-effect loci segregating at intermediate allele frequencies can allow natural populations to rapidly respond to selection. Because SNF4Aγ also exhibits clinal variation in various Drosophila species, we suggest that this large-effect polymorphism is maintained by temporal and spatial temperature variation in natural environments.François Mallard, Viola Nolte, Ray Tobler, Martin Kapun and Christian Schlöttere

    First Report of Root and Collar Rot Caused by Fusarium tricinctum and Fusarium avenaceum on Carrot in France

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    In 2017, carrot (Daucus carota L.) seed production represented around 22% of the area devoted to the production of vegetable fine seeds. Since 2015, symptoms of root and collar rot have been observed in carrot seed parcels located in the Central Region, one of the most important production zone in France. Diseased plants became dried prematurely, compromising seed development. Depending on the year and the climatic conditions, the disease in a same field can be considered as epidemic (rate losses between 30 to 100% of plants in 2016) or can impact plants more sporadically (less than 10% in 2017 and 2018). Sixteen diseased carrot samples (Nantaise type) were collected from five fields of seed production in the Central Region: two fields in 2016 and 2017, one field in 2018. Seven fungal isolates, obtained from lesions, were grown on Potato Dextrose Agar (PDA) medium and incubated for one week at 20°C in darkness. From the colony top, fluffy mycelium pigmented in pink, red, purple or orange was observed, with a red color at the reverse. To induce sporulation, isolates were grown on Synthetischer Nährstoffarmer Agar (SNA) medium during three weeks at 24°C in near-UV radiations under a 12h-photoperiod. Four isolates (FT001, FT003, FT007, FT017) developed orange sporodochia with lunar or crescent-shaped macroconidia (40.3 ± 0.8 × 5.9 ± 0.1 µm; n=90) and lime or pear-shaped microconidia (10.7 ± 0.2 × 7.7 ± 0.2 µm; n=60), as described in Fusarium tricinctum (Leslie and Summerell 2006). Three isolates (FA001, FA002, FA006) developed orange sporodochia with sickle-shaped macroconidia (50.5 ± 1.1 × 5.0 ± 0.1 µm; n= 60), but no microconidia, as observed in Fusarium avenaceum (Leslie and Summerell 2006). To confirm the identification, DNA was extracted from the mycelium of the seven isolates and molecular markers (ATP citrate lyase, ACL1; RNA polymerase II, RPB2) were used for PCR amplification (Gräfenhan et al. 2011; O’Donnell et al. 2013). The ACL1 sequences from the seven field isolates (GenBank Accession numbers MK183788-MK183791; MK181528-MK181530) were 99-100% identical with the ACL1 sequence of a reference F. tricinctum isolate (query coverages 99-100%; E-values of 0.0) and a reference F. avenaceum isolate (query coverages 98-99%; E-values of 0.0) [respectively DAOM 235630 isolate, GenBank Acc. No. JX397813 and BBA64135 isolate, GenBank Acc. No. JX397768, Niessen et al. 2012]. Using RPB2, sequences from field isolates (GenBank Acc. No. MK183109-MK183115) were 98.5-99.9% identical with the RPB2 sequence of a reference F. tricinctum isolate (query coverages 96-100%; E-values of 0.0) and a reference F. avenaceum isolate (query coverages 95-100%; E-values of 0.0) [respectively MRC 1895 isolate, GenBank Acc. No. MH582113 and MRC 1413 isolate, GenBank Acc. No. MH582082, O’Donnell et al. 2018]. To confirm pathogenicity, FT001 and FA002 were inoculated on collars of 10-weeks old carrot plants in the greenhouse. Forty plants per isolate and 40 control plants were used. Ten microliters of a conidial suspension (105 conidia.mL-1) - or sterile water for the controls - were deposited at the collar, previously wounded using a scalpel blade. Necrotic lesions developed at 20 dpi (FT001) and at 30 dpi (FA002). Fusarium tricinctum and F. avenaceum were re-isolated from the lesions and identified by sequencing using ACL1 and RPB2 markers. No isolation of Fusarium was obtained from the controls. To our knowledge, this is the first report of F. tricinctum and F. avenaceum in carrot in France

    The Alpha 7 Nicotinic Acetylcholine Receptor Does Not Affect Neonatal Brain Injury

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    Inflammation plays a central role in the development of neonatal brain injury. The alpha 7 nicotinic acetylcholine receptor (α7nAChR) can modulate inflammation and has shown promising results as a treatment target in rodent models of adult brain injury. However, little is known about the role of the α7nAChR in neonatal brain injury. Hypoxic-ischemic (HI) brain injury was induced in male and female C57BL/6 mice, α7nAChR knock-out (KO) mice and their littermate controls on postnatal day (PND) 9–10. C57BL/6 pups received i.p. injections of α7nAChR agonist PHA 568487 (8 mg/kg) or saline once daily, with the first dose given directly after HI. Caspase-3 activity and cytokine mRNA expression in the brain was analyzed 24 h after HI. Motor function was assessed 24 and 48 h after HI, and immunohistochemistry was used to assess tissue loss at 24 h and 7 days after HI and microglial activation 7 days after HI. Activation of α7nAChR with the agonist PHA 568487 significantly decreased CCL2/MCP-1, CCL5/RANTES and IL-6 gene expression in the injured brain hemisphere 24 h after HI compared with saline controls in male, but not female, pups. However, α7nAChR activation did not alter caspase-3 activity and TNFα, IL-1β and CD68 mRNA expression. Furthermore, agonist treatment did not affect motor function (24 or 48 h), neuronal tissue loss (24 h or 7 days) or microglia activation (7 days) after HI in either sex. Knock-out of α7nAChR did not influence neuronal tissue loss 7 days after HI. In conclusion, targeting the α7nAChR in neonatal brain injury shows some effect on dampening acute inflammatory responses in male pups. However, this does not lead to an effect on overall injury outcome
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