3,766 research outputs found
An insight into the role of trissolcus mitsukurii as biological control agent of halyomorpha halys in Northeastern Italy
11noSustainable strategies such as classical or augmentative biological control are currently being evaluated for the long-term management of the alien invasive pest Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). A three-year study carried out in northeastern Italy was performed to investigate the distribution and field performance of the H. halys egg parasitoid Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae), in comparison with other parasitoid species. In the study area, adventive populations of T. mitsukurii were present since 2016, representing the earliest detection of this species in Europe. Trissolcus mitsukurii was the most abundant parasitoid and showed a higher “parasitoid impact” (i.e., number of parasitized eggs over the total number of field-collected eggs) compared to the other species, i.e., Anastatus bifasciatus (Geoffroy) (Hymenoptera: Eupelmidae), Trissolcus basalis (Wollaston) and Trissolcus kozlovi Rjachovskij (Hymenoptera: Scelionidae). The hyperparasitoid Acroclisoides sinicus (Huang and Liao) (Hymenoptera: Pteromalidae) was also recorded. Phylogenetic analysis of T. mitsukurii population distinguished two clades, one covering samples from Italy, Japan and China, the other from South Korea. The present study provides promising results for the biological control of a pest that is having a dramatic impact on a wide range of crops worldwide.openopenScaccini D.; Falagiarda M.; Tortorici F.; Martinez-Sanudo I.; Tirello P.; Reyes-Dominguez Y.; Gallmetzer A.; Tavella L.; Zandigiacomo P.; Duso C.; Pozzebon A.Scaccini, D.; Falagiarda, M.; Tortorici, F.; Martinez-Sanudo, I.; Tirello, P.; Reyes-Dominguez, Y.; Gallmetzer, A.; Tavella, L.; Zandigiacomo, P.; Duso, C.; Pozzebon, A
The role of disulfide bond replacements in analogues of the Tarantula toxin ProTx-II and their effects on inhibition of the voltage-gated sodium ion channel Nav1.7
Spider venom toxins, such as Protoxin-II (ProTx-II), have recently received much attention as selective Nav1.7 channel blockers, with potential to be developed as leads for the treatment of chronic nocioceptive pain. ProTx-II is a 30-amino acid peptide with three disulfide bonds that has been reported to adopt a well-defined inhibitory cystine knot (ICK) scaffold structure. Potential drawbacks with such peptides include poor pharmacodynamics and potential scrambling of the disulfide bonds in vivo. In order to address these issues, in the present study we report the solid-phase synthesis of lanthionine-bridged analogues of ProTx-II, in which one of the three disulfide bridges is replaced with a thioether linkage, and evaluate the biological properties of these analogues. We have also investigated the folding and disulfide bridging patterns arising from different methods of oxidation of the linear peptide precursor. Finally, we report the X-ray crystal structure of ProTx-II to atomic resolution; to our knowledge this is the first crystal structure of an ICK spider venom peptide not bound to a substrate
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Maternal Hyperleptinemia Increases Arterial Stiffening and Alters Vasodilatoy Responses to Insulin in Adult Male Mice Offspring
Cardiovascular disease (CVD) is the number one cause of death in the U.S., and exposure to adverse maternal environments has been associated with the development of CVD including hypertension. Gestational diabetes mellitus (GDM) is an adverse maternal environment that has been associated with metabolic and CVD outcomes in the offspring. Key features of GDM and CVD are maternal hyperleptinemia and vascular disfunction/remodeling, respectively. Yet, there is limited information on the effects of maternal hyperleptinemia has on the function and structure of the offspring’s resistance vasculature. We hypothesize that alterations in offspring’s resistance artery structure and function underlie programming mechanisms for cardiovascular disease that are associated with maternal hyperleptinemia and GDM. To test this hypothesis, we used Leprdb/+ mice dams, which exhibit maternal hyperleptinemia and wildtype (WT) as controls. Vascular function was assessed in WT male offspring of control and hyperleptinemic dams at 31 weeks of age, after half the offspring had been fed a high fat diet (HFD) for 6 weeks. On a standard diet (SD), offspring of hyperleptinemic dams had mesenteric arteries with larger internal diameters than those of WT dams (258.36±14.99 vs 233.65±9.36 μm, p<0.05) indicative of outwardly remodeled, and enhanced maximal vasodilatory responses to insulin (39.97±6.71 vs 32.23±5.07 %, p<0.05). In offspring of WT, but not hyperleptinemic dams, HFD increased vessel wall cross-sectional area (18590.01±1251.16 vs 12807.20±1060.70 μm2, p<0.05), and enhanced the maximal vasodilatory response to acetylcholine (33.74±4.92 vs 21.86±2.73 %, p<0.05). HFD reduced the maximal response to insulin in offspring of hyperleptinemic dams compared to their WT and lean controls (21.88±3.80 vs 37.42±7.84 and 39.97±6.71 % respectively, p<0.05). Offspring of hyperleptinemic dams fed a HFD had increased elastic moduli normalized as a function of the percolation of the internal elastic lamina compared to their WT and lean controls (0.53±0.038 vs 0.34±0.023 and 0.38±0.032 ×106 dynes/cm2 respectively, p<0.05). Offspring of hyperleptinemic dams also had stiffer arteries at high pressure under both dietary conditions (2.36±0.35 vs 1.45±0.11 ×106 dynes/cm2, p<0.05). We conclude that when mice were fed a SD, maternal hyperleptinemia had beneficial effects to offspring’s vascular health, but did not protect offspring fed a HFD. Furthermore, maternal hyperleptinemia induced arterial stiffness in offspring regardless of diet. These results suggest that GDM programs offspring vascular function and structure through mechanisms that may be in part dependent on circulating maternal leptin levels and are differentially affected by postnatal developmental exposures
The impact of silent vascular brain burden in cognitive impairment in Parkinson's disease
White matter hyperintensities (WMHs) detected by magnetic
resonance imaging (MRI) of the brain are associated with dementia and cognitive
impairment in the general population and in Alzheimer's disease. Their effect in
cognitive decline and dementia associated with Parkinson's disease (PD) is still
unclear. METHODS: We studied the relationship between WMHs and cognitive state in
111 patients with PD classified as cognitively normal (n = 39), with a mild
cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross-sectional
and follow-up study. Cognitive state was evaluated with a comprehensive
neuropsychological battery, and WMHs were identified in FLAIR and T2-weighted
MRI. The burden of WMHs was rated using the Scheltens scale. RESULTS: No
differences in WMHs were found between the three groups in the cross-sectional
study. A negative correlation was observed between semantic fluency and the
subscore for WMHs in the frontal lobe. Of the 36 non-demented patients
re-evaluated after a mean follow-up of 30 months, three patients converted into
MCI and 5 into dementia. Progression of periventricular WMHs was associated with
an increased conversion to dementia. A marginal association between the increase
in total WMHs burden and worsening in the Mini Mental State Examination was
encountered. CONCLUSIONS: White matter hyperintensities do not influence the
cognitive status of patients with PD. Frontal WMHs have a negative impact on
semantic fluency. Brain vascular burden may have an effect on cognitive
impairment in patients with PD as WMHs increase overtime might increase the risk
of conversion to dementia. This finding needs further confirmation in larger
prospective studies
Comparing novel shotgun DNA sequencing and state-of-the-art proteomics approaches for authentication of fish species in mixed samples
Replacement of high-value fish species with cheaper varieties or mislabelling of food unfit for human con-sumption is a global problem violating both consumers' rights and safety. For distinguishing fish species in pure samples, DNA approaches are available; however, authentication and quantification of fish species in mixtures remains a challenge. In the present study, a novel high-throughput shotgun DNA sequencing approach applying masked reference libraries was developed and used for authentication and abundance calculations of fish species in mixed samples. Results demonstrate that the analytical protocol presented here can discriminate and predict relative abundances of different fish species in mixed samples with high accuracy. In addition to DNA analyses, shotgun proteomics tools based on direct spectra comparisons were employed on the same mixture. Similar to the DNA approach, the identification of individual fish species and the estimation of their respective relative abundances in a mixed sample also were feasible. Furthermore, the data obtained indicated that DNA sequencing using masked libraries predicted species-composition of the fish mixture with higher specificity, while at a taxonomic family level, relative abundances of the different species in the fish mixture were predicted with slightly higher accuracy using proteomics tools. Taken together, the results demonstrate that both DNA and protein-based approaches presented here can be used to efficiently tackle current challenges in feed and food authentication analyses.Proteomic
miR-146a is a pivotal regulator of neutrophil extracellular trap formation promoting thrombosis.
Neutrophil extracellular traps (NETs) induce a procoagulant response linking inflammation and thrombosis. Low levels of miR-146a, a brake of inflammatory response, are involved in higher risk for cardiovascular events, but the mechanisms explaining how miR-146a exerts its function remain largely undefined. The aim of this study was to explore the impact of miR-146a deficiency in NETosis both, in sterile and non-sterile models in vivo, and to inquire into the underlying mechanism. Two models of inflammation were performed: 1) Ldlr-/- mice transplanted with bone marrow from miR-146a-/- or wild type (WT) were fed high-fat diet, generating an atherosclerosis model; and 2) an acute inflammation model was generated by injecting lipopolysaccharide (LPS) (1 mg/Kg) into miR-146a-/- and WT mice. miR-146a deficiency increased NETosis in both models. Accordingly, miR-146a-/- mice showed significant reduced carotid occlusion time and elevated levels of NETs in thrombi following FeCl3-induced thrombosis. Infusion of DNAse I abolished arterial thrombosis in WT and miR-146a-/- mice. Interestingly, miR-146a deficient mice have aged, hyperreactive and pro-inflammatory neutrophils in circulation that are more prone to form NETs independently of the stimulus. Furthermore, we demonstrated that community acquired pneumonia (CAP) patients with reduced miR-146a levels associated with the T variant of the functional rs2431697, presented an increased risk for cardiovascular events due in part to an increased generation of NETs.This work was supported by research grants from Instituto de Salud Carlos III (ISCIII), Fondo Europeo de Desarrollo Regional “Investing in your future” (PI17/00051 y PI17/01421) (PFIS18/0045: A.M. de los Reyes-García) (CD18/00044: S. Águila), and Fundación Séneca (19873/GERM/15). The CNIC is supported by the ISCIII, the Ministerio de Ciencia, Innovación y Universidades (MCIU), and the Fundación Pro CNIC, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). A.B. Arroyo has a research fellowship from Sociedad Española de Trombosis y Hemostasia (SETH). The MCIU supported A.dM. (predoctoral contract BES-2014-067791).S
First bounds on the very high energy gamma-ray emission from Arp 220
Using the Major Atmospheric Gamma Imaging Cherenkov Telescope (MAGIC), we
have observed the nearest ultra-luminous infrared galaxy Arp 220 for about 15
hours. No significant signal was detected within the dedicated amount of
observation time. The first upper limits to the very high energy -ray
flux of Arp 220 are herein reported and compared with theoretical expectations.Comment: Accepted for publication in Ap
Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope
We report the detection of a new source of very high energy (VHE, E_gamma >=
100GeV) gamma-ray emission located close to the Galactic Plane, MAGIC
J0616+225, which is spatially coincident with SNR IC443. The observations were
carried out with the MAGIC telescope in the periods December 2005 - January
2006 and December 2006 - January 2007. Here we present results from this
source, leading to a VHE gamma-ray signal with a statistical significance of
5.7 sigma in the 2006/7 data and a measured differential gamma-ray flux
consistent with a power law, described as dN_gamma/(dA dt dE) = (1.0 +/-
0.2)*10^(-11)(E/0.4 TeV)^(-3.1 +/- 0.3) cm^(-2)s^(-1)TeV^(-1). We briefly
discuss the observational technique used and the procedure implemented for the
data analysis. The results are put in the perspective of the multiwavelength
emission and the molecular environment found in the region of IC443.Comment: Accepted by ApJ Letter
Constraints on the steady and pulsed very high energy gamma-ray emission from observations of PSR B1951+32/CTB 80 with the MAGIC Telescope
We report on very high energy gamma-observations with the MAGIC Telescope of
the pulsar PSR B1951+32 and its associated nebula, CTB 80. Our data constrain
the cutoff energy of the pulsar to be less than 32 GeV, assuming the pulsed
gamma-ray emission to be exponentially cut off. The upper limit on the flux of
pulsed gamma-ray emission above 75 GeV is 4.3*10^-11 photons cm^-2 sec^-1, and
the upper limit on the flux of steady emission above 140 GeV is 1.5*10^-11
photons cm^-2 sec^-1. We discuss our results in the framework of recent model
predictions and other studies.Comment: 7 pages, 7 figures, replaced with published versio
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